7 Very High Pressure Compressors (over 100 MPa [14500 psi])
- 格式:pdf
- 大小:481.43 KB
- 文档页数:49
2021年最新压缩机专业词中英文对照容积式压缩机 positive displacement compressor往复式压缩机(活塞式压缩机) reciprocating compressor回转式压缩机 rotary compressor滑片式压缩机 sliding vane compressor单滑片回转式压缩机 single vane rotary compressor 滚动转子式压缩机 rolling rotor compressor三角转子式压缩机 triangle rotor compressor多滑片回转式压缩机 multi-vane rotary compressor 滑片 blade旋转活塞式压缩机 rolling piston compressor涡旋式压缩机 scroll compressor涡旋盘 scroll固定涡旋盘 stationary scroll, fixed scroll驱动涡旋盘 driven scroll, orbiting scroll斜盘式压缩机(摇盘式压缩机) swash plate compressor斜盘 swash plate摇盘 wobble plate螺杆式压缩机 screw compressor单螺杆压缩机 single screw compressor阴转子 female rotor阳转子 male rotor主转子 main rotor闸转子 gate rotor无油压缩机 oil free compressor膜式压缩机 diaphragm compressor活塞式压缩机 reciprocating compressor单作用压缩机 single acting compressor双作用压缩机 double acting compressor双效压缩机 dual effect compressor双缸压缩机 twin cylinder compressor闭式曲轴箱压缩机 closed crankcase compressor开式曲轴箱压缩机 open crankcase compressor顺流式压缩机 uniflow compressor逆流式压缩机 return flow compressor干活塞式压缩机 dry piston compressor双级压缩机 compound compressor多级压缩机 multistage compressor差动活塞式压缩机 stepped piston compound compressor, differential piston compressor串轴式压缩机 tandem compressor, dual compressor截止阀 line valve, stop valve排气截止阀 discharge line valve吸气截止阀 suction line valve部分负荷旁通口 partial duty port能量调节器 energy regulator容量控制滑阀 capacity control slide valve 容量控制器 capacity control消声器 muffler联轴节 coupling曲轴箱 crankcase曲轴箱加热器 crankcase heater轴封 crankcase seal, shaft seal填料盒 stuffing box轴封填料 shaft packing机械密封 mechanical seal波纹管密封 bellows seal转动密封 rotary seal迷宫密封 labyrinth seal轴承 bearing滑动轴承 sleeve bearing偏心环 eccentric strap滚珠轴承 ball bearing滚柱轴承 roller bearing滚针轴承 needle bearing止推轴承 thrust bearing外轴承 pedestal bearing臼形轴承 footstep bearing轴承箱 bearing housing止推盘 thrust collar偏心销 eccentric pin曲轴平衡块 crankshaft counterweight, crankshaft balance weight曲柄轴 crankshaft偏心轴 eccentric type crankshaft曲拐轴 crank throw type crankshaft连杆 connecting rod连杆大头 crank pin end连杆小头 piston pin end曲轴 crankshaft主轴颈 main journal曲柄 crank arm, crank shaft曲柄销 crank pin曲拐 crank throw曲拐机构 crank-toggle阀盘 valve disc阀杆 valve stem阀座 valve seat阀板 valve plate阀盖 valve cage阀罩 valve cover阀升程限制器valve lift guard阀升程 valve lift阀孔 valve port吸气口 suction inlet压缩机气阀 compressor valve 吸气阀 suction valve排气阀 delivery valve圆盘阀 disc valve环片阀 ring plate valve簧片阀 reed valve舌状阀 cantilever valve条状阀 beam valve提升阀 poppet valve菌状阀 mushroom valve杯状阀 tulip valve缸径 cylinder bore余隙容积 clearance volume附加余隙(补充余隙) clearance pocket活塞排量 swept volume, piston displacement理论排量 theoretical displacement实际排量 actual displacement实际输气量 actual displacement, actual output of gas气缸工作容积 working volume of the cylinder活塞行程容积 piston displacement气缸 cylinder气缸体 cylinder block气缸壁 cylinder wall水冷套 water cooled jacket气缸盖(气缸头) cylinder head安全盖(假盖) safety head假盖 false head活塞环 piston ring气环 sealing ring刮油环 scraper ring油环 scrape ring活塞销 piston pin活塞 piston活塞行程 piston stroke吸气行程 suction stroke膨胀行程 expansion stroke压缩行程 compression stroke排气行程 discharge stroke升压压缩机 booster compressor立式压缩机 vertical compressor卧式压缩机 horizontal compressor角度式压缩机 angular type compressor对称平衡型压缩机 symmetrically balanced type compressor压缩机参数词汇1. performance parameter 性能参数——表征压缩机主要性能的诸参数,如:气量、压力、温度、功率及噪声、振动等2. constructional parameter 结构参数——表征压缩机结构特点的诸参数,如:活塞力、行程、转速、列数、各级缸径、外形尺寸等3. inlet pressure/suction pressure 吸气压力(吸入压力)——在标准吸气位置气体的平均绝对全压力。
SCROLL COMPRESSORSSF 1-6 (1.5-5.5 kW/2-7.5 hp) / SF+ 2-22 (2.2-22 kW/3-30 hp)PURE OIL-FREE AIRAs there is no metal-to-metal contact between the compression scrolls, there is no need for oil lubrication in the compression chamber. T herefore, the scroll compression principle guarantees high-quality, oil-free air. As a result, the SF compressor isoil-free in every way.ENERGY EFFICIENCYThe SF scroll compressors, standard equipped with IE3 Premium efficiency motors, are suited for sensitive applications which require flexibility and energy efficiency. Unloaded power consumption is eliminated thanks to the simple start/stop control. Advanced scroll technology guarantees an optimalfree air delivery and low duty cycle applications.EXTREMEL Y LOW NOISE LEVELThe slow speed of the scroll compression elements ensures that the SF scroll compressors are extremely quiet. Sound levels are as low as 53 dB(a), making the SF the perfect choice for your sensitive working environment.SIMPLICITY AND RELIABILITYThe SF scroll compressors stand for simplicity and reliability. The compressor has a minimal number of moving parts, ensuring a long operating life with limited service interventions. With their integrated design, Atlas Copco’s SF scroll compressors have a minimal footprint and offereasy serviceability.PROVEN PEACE OF MINDFor over sixty years, Atlas Copco has been leading the industry in oil-free compressed air technology, drawing on vast experience and continuous technological innovations.You can rest assured at all times: severe certification and testing procedures are conducted to ensure air is suppliedto the highest standards of quality control.110438296Integrated receiverPlug and play solution, lower installation costs with 30l, 270l and 500ltank-mounted options.7Elektronikon® (SF+)Monitoring features include warning indications, maintenance schedulingand online visualization of running conditions.8Innovative designThe new compact vertical setup enables easy access for maintenance,improves cooling allowing lower working temperatures and providesvibration damping.9SF-Skid/T win• Suitable for installation at the point of useor for integration into an existing airnetwork: designed with simplicity in mind.Cooler & piping• An oversized cooler improves theperformance of the unit.• The use of aluminum pipes and thevertically oversized check valve improvereliability over lifetime and assure thehigh quality of your compressed air.10Air inlet filterHigh efficiency paper cartridge air inlet filter, eliminating dust andparticles down to 1 µm.1Automatic regulationAutomatic stop when the required working pressure is reached,avoiding unnecessary energy costs.2High efficiency scroll elementAir-cooled scroll compressor element offeringproven durability and reliability in operation,in addition to solid efficiency.IP55 Class F/IE3 motorTotally enclosed air-cooled IP55 Class F motor,complying with IE3 & Nema Premiumefficiency standards.Refrigerant dryerCompact & optimized integrated refrigerant dryer,ensuring the delivery of dry air, preventing rust andcorrosion in your compressed air network.5Silent canopyA sound insulated canopy makes extremely low noise levels as low as53 dB(A) possible, allowing to install the unit closer to the point of use.6452381® Mk5 High efficiency scroll elementAir-cooled scroll compressor elements with 8 and 10 bar variants, offering proven durability and reliability in operation, in addition to superior efficiency.3Optimized cooler & pipingThe air cooler is finetuned for improved performance, while the use of aluminum & stainless steel pipes improve reliability over lifetime and assure the high quality of compressed air.7motors, complying with IE3 Premium efficiency standards.Smart designOutstanding user-friendly design, with safety in operation & ease of serviceability in mind.8Refrigerant dryerCompact & optimized integrated refrigerant dryer ensuring the delivery of dry air, preventing rust and corrosion in the installed compressed air network.4SF Duplex• Duplex set-up with two cubicles, one/two main modules and one/two modules as back-up.• Elektronikon ® regulates each set of compressor modules via an integrated central control system.• Enclosed in sound-insulated bodywork.Silent canopyThanks to the low-noise scroll element, optimized super-silent fan and sound-insulated canopy, best in class noise levels possible are achieved.512345678ADVANCED SCROLL TECHNOLOGYAir compression is achieved by the interaction of a fixed and orbiting scroll. Air at inlet pressure enters the compression chamber at the exterior side of the scroll element. Once air is drawn in, the orbiting scroll seals off the inlet port. As the scroll continues to orbit, the air is progressively compressed into an increasingly smaller ‘pocket’. A continuous flow of compressed air leaves the scroll element through a discharge port in the center of the fixed scroll. This process is continuously repeated, resulting in the delivery of pulse-free compressed air.Variable flow technology (VFT)All SF + 8-22 multi-scroll compressors areequipped with the unique VFT control system. The VFT system, included in the Elektronikon ® controller, automatically starts and stops the scroll elements to exactly match the demands of your compressed air system. T heElektronikon ® control algorithm ensures that the system pressure is kept within a very narrow pressure band.WorkPlace Air System™ compressors: the sound of silenceA low noise level enables the compressor to be installed close to the compressed air application, minimizing the size of the air distribution system and reducing pressure loss and the potential for leakage. As the air treatment is completely integrated, the installation costs are substantially reduced, making multiple compressor installations practical and financially viable. T o ensure maximum energy efficiency, Atlas Copco offers both traditional on/off regulating systems where the air demand is constant.Cooling fan Suction chamber Suction opening Delivery opening Fixed scroll Orbiting scrollFail-safe temperature sensor for unit protection Compression chamber12345678Current ISO 8573-1 (2010) classes (the five main classes and the associated maximum concentration in total oil content).CLASS ZERO: THEINDUSTRY STANDARDOil-free air is used in all kinds of industries where air quality is paramount. These applications include food and beverage processing, pharmaceutical manufacturing, petrochemical processing, wastewater treatment, and many more. I n these critical environments, contamination by even the smallest quantities of oil can result in costly production downtime and product spoilage.First in oil-free air technologyOver the past 60 years Atlas Copco has pioneered the development of oil-free air technology, resulting in a range of air compressors that provide 100% pure, oil-free air. T hrough continuous research and development, Atlas Copco achieved a new milestone, setting the standard for air purity as the first manufacturer to be awarded ISO 8573-1 Class 0 certification.Eliminating any riskAs industry leader committed to meeting the needs of the most demanding customers, Atlas Copco requested the renowned T ÜV institute to type-test its range of oil-free compressors. Using the most rigorous testing methodologies available, all possible oil forms were measured across a range of temperatures andpressures. T he T ÜV found no traces of oil at all in the output air stream. T hus Atlas Copco is the first compressor manufacturer to receive Class 0 certification, according to ISO 8573-1 Class 0 Ed. 3 2010 specifications.® controller, while the SF +Elektronikon ® Graphic.Improved user-friendliness• 3.5-inch high-definition color display with clear pictograms and extra 4th LED indicator for service.• Graphical display of key parameters (day, week, month) and 32 language settings.• Internet-based compressor visualization using a simple Ethernet connection.• Graphical indication Serviceplan, remote control and connectivity functions.• Software upgrade available to control up to 6 compressors by installing the optional integrated compressor controller.4 modules61218183 modules2 modules1 moduleTECHNICAL SPECIFICATIONS* Free Air Delivery measured according ISO 1217 ed. 4 2009, Annex C.** Mean sound pressure level measured according to ISO 2151, with an uncertainty of 3 dB(A).Weights of the pack & floor-mounted units are shown in the chart.DIMENSIONSLWHL WHL WHL WH•: Optional- : Not availableCOMMITTED TO SUSTAINABLE PRODUCTIVITYWe stand by our responsibilities towards our customers, towards the environment and the people around us. We make performance stand the test of time. T his is what we call – Sustainable Productivity./sf2935 0844 48 © 2014, A t l a s C o p c o A i r p o w e r N V , B e l g i u m . A l l r i g h t s r e s。
AE4-1381May 2011ZW21 to ZW61KAE and ZW30 to ZW61KSECopeland Scroll® Water Heating CompressorsTABLE OF CONTENTSSection Page Section PageIntroduction (2)ZW**KA Application (2)ZW**KS ApplicationVapour Injection - Theory of Operation (2)Heat Exchanger and Expansion Device Sizing (3)Flash Tank Application (3)Intermediate Pressure and Vapour Injection Superheat (3)Application ConsiderationsHigh Pressure Cut-Out (4)Low Pressure Cut-Out (4)Discharge Temperature Protection (4)Discharge Temperature Control (4)Discharge Mufflers (4)Oil Dilution and Compressor Cooling (4)Electrical Considerations (5)Brazing and Vapour Injection Line (5)Low Ambient Cut-Out (5)Internal Pressure Relief Valve (5)Internal Temperature Protection (5)Quiet Shutdown (5)Discharge Check Valve (5)Motor Protector (5)Accumulators (5)Screens (6)Crankcase Heat-Single Phase (6)Crankcase Heat-Three Phase (6)Pump Down Cycle (6)Minimum Run Time (6)Reversing Valves (6)Oil Type (7)System Noise & Vibration (7)Single Phase Starting Characteristics (7)PTC Start Components (7)Electrical Connections (7)Deep Vacuum Operation (7)Shell Temperature (7)Suction & Discharge Fittings (7)Three Phase Scroll Compressors (8)Brief Power Interruptions ..........................................8Assembly Line ProceduresInstalling the Compressor (8)Assembly Line Brazing Procedure (8)Pressure Testing (8)Assembly Line System Charging Procedure (8)High Potential (AC Hipot) Testing (9)Unbrazing System Components (9)Service ProceduresCopeland Scroll Functional Check (9)Compressor Replacement After Motor Burn (10)Start Up of a New or Replacement Compressor (10)FiguresBrief Product Overview (11)ZW21KAE Envelope (R-134a) (11)ZWKAE Envelope (R-407C, Dew Point) (12)ZWKA Envelope (R-22) (12)ZWKS Envelope (R-22) (13)ZWKSE Envelope (R-407C, Dew Point) (13)Heat Pump with Vapour Injection – EXV Control (14)Heat Exchanger Schematic (14)Heat Pump with Flash Tank (15)Possible Flash Tank Configuration (15)Oil Dilution Chart (16)Crankcase Heater (17)Compressor Electrical Connection (17)Scroll Tube Brazing (17)How a Scroll Works (18)IntroductionThe ZW**KA and ZW**KS Copeland Scroll®compressors are designed for use in vapour compression heat pump water heating applications. Typical model numbers include ZW30KA-PFS and ZW61KSE-TFP. This bulletin addresses the specifics of water heating in the early part and deals with the common characteristics and general application guidelines for Copeland Scroll compressors in the later sections. Operating principles of the scroll compressor are described in Figure 15 at the end of this bulletin.As the drive for energy efficiency intensifies, water heating by fossil-fueled boilers and electric elements is being displaced by vapour compression heat pumps. Emerson Climate Technologies has developed two lines of special water heater compressors to meet the requirements of this demanding application. ZW**KA compressors are designed for lighter duty applications where the ambient temperature does not fall below 0°C and where lower water temperatures can be accepted as the ambient temperature falls. ZW**KS compressors are equipped with a vapour injection cycle which allows reliable operation in cold climates with significantly enhanced heating capacity, higher efficiency, and minimal requirement to reduce water outlet temperatures. Figure 1gives a brief product overview.Water heating is characterized by long operating hours at both high load and high compression ratios. Demand for hot water is at its highest when ambients are low and when conventional heat pump capacity falls off. On the positive side, the system refrigerant charge is usually small, so the risk to the compressor from dilution and flooded starts will usually be lower than in split type air-to-air heat pumps.Water heaters must operate in a wide range of ambient temperatures, and many systems will require some method of defrost. Some systems such as Direct Heating, Top Down Heating or Single Pass Heating operate at a constant water outlet temperature with variable water flow. Others such as Recirculation Heating, Cyclic Heating or Multipass Heating use constant water flow with the water outlet and inlet temperatures both rising slowly as the storage tank heats up. Both system types need to cope with reheating a tank where the hot water has been partially used, and reheating to the setpoint temperature is required. More complex systems deliver water at relatively low temperatures for under-floor heating circuits and are switched over to sanitary water heating a few times per day to provide higher temperature water for sanitary use. In addition, some countries have specific water temperature requirements for legionella control.ZW**KA ApplicationThe application envelopes for ZW**KA compressors are shown in Figures 2 - 4.Appropriate system hardware and control logic must be employed to ensure that the compressor is always operating within the envelope. Small short-term excursions outside the envelope are acceptable at the time of defrost when the load on the compressor is low. Operation with suction superheat of 5 -10K is generally acceptable except at an evaporating tem-perature above 100C when a minimum superheat of 10K is required.ZW**KS ApplicationThe ZW**KS* vapour-injected scroll compressors differ from ZW**KA models in many important details:• Addition of vapour injection• Significantly different application envelopes• Some differences in locked rotor amps (LRA), maximum continuous current (MCC), andmaximum operating current (MOC) – seenameplatesThe application envelopes for ZW**KS compressors are shown in Figures 5 and 6.Vapour Injection – Theory of Operation Operation with vapour injection increases the capacity of the outdoor coil and in turn the capacity and efficiency of the system – especially in low ambient temperatures. A typical schematic is shown in Figure 7. A heat exchanger is added to the liquid line and is used to cool the liquid being delivered to the heating expansion device. Part of the liquid refrigerant flow is flashed through an expansion valve on the evaporator side of the heat exchanger at an intermediate pressure and used to subcool the main flow of liquid to the main expansion device. Vapour from the liquid evaporating at intermediate pressure is fed to the vapour injection port on the ZW**KS compressor. This refrigerant is injected into the mid-compression cycle of the scroll compressor and compressed to discharge pressure. Heating capacity is increased, because low temperature liquid with lower specific enthalpy supplied to the outdoor coil increases the amount of heat that can be absorbed from the ambient air. Increased heat absorbed from the ambient increases the system condensing temperature and in turn the compressor power input. The increase in power inputalso contributes to the improvement in the overall heating capacity.Vapour Injection can be turned on and off by the addition of an optional solenoid valve on the vapour injection line on systems using a thermostatic expansion valve. Alternatively, an electronic expansion valve can be used to turn vapour injection on and off and to control the vapour injection superheat. A capillary tube is not suitable for controlling vapour injection.The major advantage of the electronic expansion valve is that it can be used to optimise the performance of the system and at the same time control the discharge temperature by injecting “wet vapour” at extreme operating conditions.The configurations and schematics shown are for reference only and are not applicable to every system. Please consult with your Emerson Application Engineer.Heat Exchanger and Expansion Device Sizing Various heat exchanger designs have been used successfully as subcoolers. In general they should be sized so that the liquid outlet temperature is less than 5K above the saturated injection temperature at the customer low temperature rating point. At very high ambient temperatures, it will normally be beneficial to turn vapour injection off to limit the load on the compressor motor. Application Engineering Bulletin AE4-1327 and Emerson Climate Technologies Product Selection Software can be used to help size the subcooling heat exchanger and thermal expansion valves, but selection and proper operation must be checked during development testing. Plate type subcoolers must be installed vertically with the injection expansion device connected at the bottom through a straight tube at least 150mm long to ensure good liquid distribution. See the schematic in Figure 8. Flash Tank ApplicationA possible flash tank configuration is shown in Figure9. This particular configuration is arranged to have flow through the flash tank and expansion devices in heating, and it bypasses the tank in defrost mode. The flash tank system works by taking liquid from the condenser and metering it into a vessel through a high-to-medium pressure expansion device. Part of the liquid boils off and is directed to the compressor vapour injection port. This refrigerant is injected into the mid-compression cycle of the scroll compressor and compressed to discharge pressure. The remaining liquid is cooled, exits from the bottom of the tank at intermediate pressure, and flows to the medium-to-low pressure expansion device which feeds the outdoor coil. Low temperature liquid with lower specific enthalpy increases the capacity of the evaporator without increasing mass flow and system pressure drops.Recommended tank sizing for single compressor application in this size range is a minimum of 200 mm high by 75 mm in diameter with 3/8 in. (9.5mm) tubing connections, although it is possible to use a larger tank to combine the liquid/vapour separation and receiver functions in one vessel. A sight tube (liquid level gauge) should be added to the tank for observation of liquid levels during lab testing. See schematic diagram Figure 10 for clarification.It is important to maintain a visible liquid refrigerant level in the tank under all operating conditions. Ideally the liquid level should be maintained in the 1/3 to 2/3 full range.Under no circumstances should the level drop to empty or rise to a full tank. As the tank level rises, liquid droplets tend to be swept into the vapour line leading to “wet” vapour injection. Although this can be useful for cooling a hot compressor, the liquid quantity cannot be easily controlled. Compressor damage is possible if the tank overflows. If liquid injection is required for any reason, it can be arranged as shown in Figures 7 and 9.Since liquid leaves the tank in a saturated state, any pressure drop or temperature rise in the line to the medium-to-low pressure expansion device will lead to bubble formation. Design or selection of the medium-to-low pressure expansion device requires careful attention due to the possible presence of bubbles at the inlet and the low pressure difference available to drive the liquid into the evaporator. An electronic expansion valve is the preferred choice. Intermediate Pressure and Vapour Injection SuperheatPressure in the flash tank cannot be set and is a complex function of the compressor inlet condition and liquid condition at the inlet of the high-to-medium pressure expansion device. However, liquid level can be adjusted, which in turn will vary the amount of liquid subcooling in the condenser (water to refrigerant heat exchanger) and vary the injection pressure. Systems with low condenser subcooling will derive the biggest gains by the addition of vapour injection. Systems operating with high pressure ratios will show the largest gains when vapour injection is applied. Such systems will have higher vapour pressure and higher injectionmass flow. Intermediate pressures in flash tank and heat exchanger systems should be very similar unless the subcooling heat exchanger is undersized and there is a large temperature difference between the evaporator and the liquid sides. Vapour exiting a flash tank will be saturated and may pick up 1 - 2K superheat in the vapour line to the compressor. Vapour injection superheat cannot be adjusted on flash tank systems. Heat exchanger systems will be at their most efficient when the vapour injection superheat is maintained at approximately 5K.APPLICATION CONSIDERATIONSHigh Pressure Cut OutIf a high pressure control is used with these compressors, the recommended maximum cut out settings are listed in Figure 1. The high pressure control should have a manual reset feature for the highest level of system protection. It is not recommended to use the compressor to test the high pressure switch function during the assembly line test.Although R-407C runs with higher discharge pressure than R-22, a common setting can be used. The cutout settings for R-134a are much lower, and the switches must be selected or adjusted accordingly.Low Pressure Cut OutA low pressure cut out is an effective protection against loss of charge or partial blockage in the system. The cut out should not be set more than 3 - 5K equivalent suction pressure below the lowest operating point in the application envelope. Nuisance trips during defrost can be avoided by ignoring the switch until defrost is finished or by locating it in the line between the evaporator outlet and the reversing valve. This line will be at discharge pressure during defrost. Recommended settings are given in Figure 1. Discharge Temperature ProtectionAlthough ZW compressors have an internal bi-metal Therm-O-Disc®(TOD) on the muffler plate, external discharge temperature protection is recommended for a higher level of protection and to enable monitoring and control of vapour injection on ZW**KS* models. The protection system should shut down the compressor when the discharge line temperature reaches 125°C. In low ambient operation, the temperature difference between the scroll center and the discharge line is significantly increased, so protection at a lower discharge temperature, e.g. 120°C when the ambient is below 0°C, will enhance system safety. For the highest level of system protection, the discharge temperature control should have a manual reset feature. The discharge sensor needs to be well insulated to ensure that the line temperature is accurately read. The insulation material must not deteriorate over the expected life of the unit.Discharge Temperature ControlSome systems use an electronic expansion valve to control the vapour injection superheat and a thermistor to monitor the discharge temperature. This combination allows the system designer to inject a small quantity of liquid to keep the discharge temperature within safe limits and avoid an unnecessary trip. Liquid injection should begin at approximately 115°C and should be discontinued when the temperature falls to 105°C. Correct functioning of this system should be verified during system development. It is far preferable to use liquid injection into the vapour injection port to keep the compressor cool rather than inject liquid into the compressor suction which runs the risk of diluting the oil and washing the oil from the moving parts. If some operation mode requires liquid injection but without the added capacity associated with “wet” vapour injection, a liquid injection bypass circuit can be arranged as shown in Figures 7 and 9.Caution: Although the discharge and oil temperature are within acceptable limits, the suction and discharge pressures cannot be ignored and must also fall within the approved application envelope.Discharge MufflersDischarge mufflers are not normally required in water heaters since the refrigerant does not circulate within the occupied space.Oil Dilution and Compressor CoolingThe oil temperature diagram shown in Figure 11is commonly used to make a judgment about acceptable levels of floodback in heat pump operation. Systems operating with oil temperatures near the lower limit line are never at their most efficient. Low ambient heating capacity and efficiency will both be higher if floodback is eliminated and the system runs with 1 - 5K suction superheat. Discharge temperature can be controlled by vapour injection, “wet” vapour injection, or even liquid injection if necessary. In this situation, the oil temperature will rise well into the safe zone, and the compressor will not be at risk of failure from diluted oil. The oil circulation rate will also be reduced as crankcase foaming disappears. Special care needs to be taken at the end of defrost to ensure that the compressor oil is not unacceptably diluted. The system will resume heating very quickly and bearing loads willincrease accordingly, so proper lubrication must be ensured.Electrical ConsiderationsMotor configuration and protection are similar to those of standard Copeland Scroll compressors. In some cases, a larger motor is required in the ZW**KS* models to handle the load imposed by operating with vapour injection. Wiring and fuse sizes should be reviewed accordingly.Brazing the Vapour Injection LineThe vapour injection connection is made from copper coated steel, and the techniques used for brazing the suction and discharge fittings apply to this fitting also. Low Ambient Cut-OutA low ambient cut-out is not required to limit heat pump operation with ZW**KS compressors. Water heaters using ZW**KA compressors must not be allowed to run in low ambients since this configuration would run outside of the approved operating envelope causing overheating or excessive wear. A low ambient cut-out should be set at 0°C for ZW**KA modelsIn common with many Copeland Scroll compressors, ZW models include the features described below: Internal Pressure Relief (IPR) ValveAll ZW compressors contain an internal pressure relief valve that is located between the high side and the low side of the compressor. It is designed to open when the discharge-to-suction differential pressure exceeds 26 - 32 bar. When the valve opens, hot discharge gas is routed back into the area of the motor protector to cause a trip.Internal Temperature ProtectionThe Therm-O-Disc® or TOD is a temperature-sensitive snap disc device located on the muffler plate between the high and low pressure sides of the compressor. It is designed to open and route excessively hot discharge gas back to the motor protector. During a situation such as loss of charge, the compressor will be protected for some time while it trips the protector. However, as refrigerant leaks out, the mass flow and the amperage draw are reduced and the scrolls will start to overheat.A low pressure control is recommended for loss of charge protection in heat pumps for the highest level of system protection. A cut out setting no lower than 2.5 bar for ZW**KA* models and 0.5 bar for ZW**KS* models is recommended. The low pressure cut-out, if installed in the suction line to the compressor, can provide additional protection against an expansion device failed in the closed position, a closed liquid line or suction line service valve, or a blocked liquid line screen, filter, orifice, or TXV. All of these can starve the compressor for refrigerant and result in compressor failure. The low pressure cut-out should have a manual reset feature for the highest level of system protection. If a compressor is allowed to cycle after a fault is detected, there is a high probability that the compressor will be damaged and the system contaminated with debris from the failed compressor and decomposed oil.If current monitoring to the compressor is available, the system controller can take advantage of the compressor TOD and internal protector operation. The controller can lock out the compressor if current draw is not coincident with the contactor energizing, implying that the compressor has shut off on its internal protector. This will prevent unnecessary compressor cycling on a fault condition until corrective action can be taken.Quiet Shut downAll scrolls in this size range have a fast acting valve in the center of the fixed scroll which provides a very quiet shutdown solution. Pressure will equalize internally very rapidly and a time delay is not required for any of the ZW compressors to restart. Also refer to the section on “Brief Power Interruption”. Discharge Check ValveA low mass, disc-type check valve in the discharge fitting of the compressor prevents the high side, high pressure discharge gas from flowing rapidly back through the compressor. This check valve was not designed to be used with recycling pump down because it is not entirely leak-proof.Motor ProtectorConventional internal line break motor protection is provided. The protector opens the common connection of a single-phase motor and the center of the Y connection on three-phase motors. The three-phase protector provides primary single-phase protection. Both types of protectors react to current and motor winding temperature.AccumulatorsThe use of accumulators is very dependent on the application. The scroll’s inherent ability to handle liquid refrigerant during occasional operating flood back situations often makes the use of an accumulator unnecessary in many designs. If flood back is excessive, it can dilute the oil to such an extent thatbearings are inadequately lubricated, and wear will occur. In such a case, an accumulator must be used to reduce flood back to a safe level that the compressor can handle.In water heaters, floodback is likely to occur when the outdoor coil frosts. The defrost test must be done at an outdoor ambient temperature of around 0°C in a high humidity environment. Liquid floodback must be monitored during reversing valve operation, especially when coming out of defrost. Excessive floodback occurs when the sump temperature drops below the safe operation line shown in Figure 11 for more than 10 seconds.If an accumulator is required, the oil return orifice should be 1 - 1.5mm in diameter depending on compressor size and compressor flood back results. Final oil return hole size should be determined through testing. ScreensScreens with a mesh size finer than 30 x 30 (0.6mm openings) should not be used anywhere in the system with these compressors. Field experience has shown that finer mesh screens used to protect thermal expansion valves, capillary tubes, or accumulators can become temporarily or permanently plugged with normal system debris and block the flow of either oil or refrigerant to the compressor. Such blockage can result in compressor failure.Crankcase Heater - Single PhaseCrankcase heaters are not required on single phase compressors when the system charge is not over 120% of the limit shown in Figure 1. A crankcase heater is required for systems containing more than 120% of the compressor refrigerant charge limit listed in Figure 1. This includes long line length systems where the extra charge will increase the standard factory charge above the 120% limit.Experience has shown that compressors may fill with liquid refrigerant under certain circumstances and system configurations, notably after longer off cycles when the compressor has cooled. This may cause excessive start-up clearing noise, or the compressor may lock up and trip on the protector several times before starting. The addition of a crankcase heater will reduce customer noise and light dimming complaints since the compressor will no longer have to clear out liquid during startup. Figure 12lists the crankcase heaters recommended for the various models and voltages.Crankcase Heat – Three-PhaseA crankcase heater is required for three-phase compressors when the system charge exceeds the compressor charge limit listed in Figure 1and an accumulator cannot be piped to provide free liquid drainage during the off cycle.Pump Down CycleA pump down cycle for control of refrigerant migration is not recommended for scroll compressors of this size. If a pump down cycle is used, a separate external check valve must be added.The scroll discharge check valve is designed to stop extended reverse rotation and prevent high-pressure gas from leaking rapidly into the low side after shut off. The check valve will in some cases leak more than reciprocating compressor discharge reeds, normally used with pump down, causing the scroll compressor to cycle more frequently. Repeated short-cycling of this nature can result in a low oil situation and consequent damage to the compressor. The low-pressure control differential has to be reviewed since a relatively large volume of gas will re-expand from the high side of the compressor into the low side on shut down. Minimum Run TimeThere is no set answer to how often scroll compressors can be started and stopped in an hour, since it is highly dependent on system configuration. Other than the considerations in the section on Brief Power Interruptions, there is no minimum off time. This is because scroll compressors start unloaded, even if the system has unbalanced pressures. The most critical consideration is the minimum run time required to return oil to the compressor after startup.Since water heaters are generally of compact construction, oil return and short cycling issues are rare. Oil return should not be a problem unless the accumulator oil hole is blocked.Reversing ValvesSince Copeland Scroll compressors have very high volumetric efficiency, their displacements are lower than those of comparable capacity reciprocating compressors. As a result, Emerson recommends that the capacity rating on reversing valves be no more than 2 times the nominal capacity of the compressor with which it will be used in order to ensure proper operation of the reversing valve under all operating conditions.The reversing valve solenoid should be wired so that the valve does not reverse when the system isshut off by the operating thermostat in the heating or cooling mode. If the valve is allowed to reverse at system shutoff, suction and discharge pressures are reversed to the compressor. This results in pressures equalizing through the compressor which can cause the compressor to slowly rotate until the pressures equalize. This condition does not affect compressor durability but can cause unexpected sound after the compressor is turned off.Oil TypeThe ZW**K* compressors are originally charged with mineral oil. A standard 3GS oil may be used if the addition of oil in the field is required. See the compressor nameplate for original oil charge. A complete recharge should be ~100 ml less than the nameplate value.ZW**K*E are charged with POE oil. Copeland 3MAF or Ultra 22 CC should be used if additional oil is needed in the field. Mobil Arctic EAL22CC, Emkarate RL22, Emkarate 32CF and Emkarate 3MAF are acceptable alternatives. POE oil is highly hygroscopic, and the oil should not be exposed to the atmosphere except for the very short period required to make the brazing connections to the compressor.System Noise and VibrationCopeland Scroll compressors inherently have low sound and vibration characteristics, but the characteristics differ in some respects from those of reciprocating or rotary compressors. The scroll compressor makes both a rocking and a torsional motion, and enough flexibility must be provided to prevent vibration transmission into any lines attached to the unit. This is usually achieved by having tubing runs at least 30cm long parallel to the compressor crankshaft and close to the shell. ZW compressors are delivered with rubber grommets to reduce vibration transmission to the system baseplate.Single Phase Starting CharacteristicsStart assist devices are usually not required, even if a system utilizes non-bleed expansion valves. Due to the inherent design of the Copeland Scroll, the internal compression components always start unloaded even if system pressures are not balanced. In addition, since internal compressor pressures are always balanced at startup, low voltage starting characteristics are excellent for Copeland Scroll compressors. Starting current on any compressor may result in a significant “sag” in voltage where a poor power supply is encountered. The low starting voltage reduces the starting torque of the compressor and subsequently increases the start time. This could cause light dimming or a buzzing noise where wire is pulled through conduit. If required, a start capacitor and potential relay can be added to the electrical circuit. This will substantially reduce start time and consequently the magnitude and duration of both light dimming and conduit buzzing.PTC Start ComponentsFor less severe voltage drops or as a start boost, solid state Positive Temperature Coefficient devices rated from 10 to 25 ohms may be used to facilitate starting for any of these compressors.Electrical ConnectionThe orientation of the electrical connections on the Copeland Scroll compressors is shown in Figure 13 and is also shown on the wiring diagram on the top of the terminal box cover.Deep Vacuum OperationScrolls incorporate internal low vacuum protection and will stop pumping (unload) when the pressure ratio exceeds approximately 10:1. There is an audible increase in sound when the scrolls start unloading. This feature does not prevent overheating and destruction of the scrolls, but it does protect the power terminals from internal arcing.Copeland Scroll compressors(as with any refrigerant compressor) should never be used to evacuate a refrigeration or air conditioning system. The scroll compressor can be used to pump down refrigerant in a unit as long as the pressures remain within the operating envelope. Prolonged operation at low suction pressures will result in overheating of the scrolls and permanent damage to the scroll tips, drive bearings and internal seal. (See AE24-1105 for proper system evacuation procedures.)Shell TemperatureCertain types of system failures, such as condenser or evaporator blockage or loss of charge, may cause the top shell and discharge line to briefly but repeatedly reach temperatures above 175ºC as the compressor cycles on its internal protection devices. Care must be taken to ensure that wiring or other materials, which could be damaged by these temperatures, do not come in contact with these potentially hot areas. Suction and Discharge FittingsCopeland Scroll compressors have copper plated steel suction and discharge fittings. These fittings are far more rugged and less prone to leaks than。
MAIN COMPONENTS1. Compressor unit : The unit should be installed on a level floor capable of taking the weight of the compressor.2. Compressed air outlet valve.3. Delivery pipe : The max . total pipe length can be calculated from L = L = Length of the pipe (m)P = Max. allowable pressure drop (recommended 0.1 bar (1.5psi)) d = Inner diameter of the pipe (mm)P = Absolute pressure at compressor outlet (bar) Qc = Free air delivery of the compressor (l/s)4. Ventilation :The inlet grid(s) and ventilation fan should be installed in such a way that any recirculation of cooling air to the inlet grating of the compressor is avoided.The air velocity to the grid(s) has to be limited to 5 m/s. The maximum air temperature at compressor intake opening is 46 C, min 0 C. Alternative 1 and 3 :The required ventilation to limit the compressor room temperature can be calculated from :Qv = (1.06N + 1.2D) TQv = Required cooling air flow (m /s) N = Nominal motor power (kW)T = Temperature increase in the compressor room. ( C) D = Electric power dryer. Alternative 2 and 4 :The fan capacity should match the compressor - fan capacity at a pressure head equal to the pressure drop caused by cooling air ducts.(10) Max. allowable pressure drop in ducting before or after the compressor = 30 Pa 5. Drain pipes to drain collector must not dip into the water. For draining of pure condensate water, install an oil / water seperator. Consult Atlas Copco.Drain pipes of different compressors may not be interconnected before the (atmospheric) collector. Interconnecting drain pipes of different compressors can damage the electronic drains of the compressor.6. Control cubicle with monitoring panel.7. Power supply cable to be installed by a qualified electrician. For the right cable size, see Atlas Copco technical data. In case of IT network, consult Atlas Copco.To preserve the ingress protection rating of the electric cubicle, it is absolutely necessary to use a proper cable gland when connecting the supply cable to the compressor.8. Filter type DD for general purpose filtration (particle removal down to 1 micron with a maximum oil carry over of 0.5 ppm).A high efficiency UD+ filter may be installed instead of DD filter (particle removal down to 0.01 micron and max. oil carry over of 0.01ppm)Should oil vapours and odeurs be undesirable, a QD active carbon filter should be installed after the UD+ filter.It is recommended to install by-pass pipes over each filter together with ball valves in order to isolate the filters during service operations, without interrupting the compressed air delivery.9. The air receiver (optional) should be installed in a frost-free room on a solid, level floor. For normal air consumption, the volume of the air net (receiver and piping) can be calculated as follows:V=(0.25 x Qc x P1 x To)/(fmax x P xT1) V = Volume of the air net in l.Qc = Free air delivery of the compressor in l/sP1 = Compressor air inlet pressure in bar absolute fmax = Cycle frequency=1 cycle/30s P =Punload - Pload in barT1 = Compressor air inlet temperature in K T0 = Air receiver temperature KA safety valve need to be foreseen on the air receiver.10. Cooling air outlet grating of AIR/OIL coolers.11. Provision for energy recovery system.12. Cooling air inlet grating.P x d x P450 x Qc1.855Fini wt.Approved.TreatmentMaterial Name Drawn byDes checked.ScaleBlank wt .Prod checked.FamilyBlank nr.KgDesignation SheetINVReplacesCompare DateDrawing owner/Confidentiality Class STATUSTolerances, if not indicated, according to:A1Not Applicable 119/08/201798203002231 : 200N/AInternalNot ApplicableApproved InternalINEsdAPIGA75-110 VSD+acc. to 1102 KINSTALLATION PROPOSAL Drawing format EdPosi-tionModified fromDateIntr./Appd.123456789A10BCDEFGParent 3D modelEd . Version 3DC O N F IDE N T I A L :T h i s d o c u m e n t i s o u r p r o p e r t y a n d s h a l l n o t w i t h o u t o u r p u r p e r m i s s i o n b e a l t e r e d ,c o p i e d , u s e d f o r m a n u f a c t u r i n g o r c o m m u n i c a t e d t o a n y o t h e r p e r s o n o r c o m p a n y00-9820300223A l l m a t e r i a l s s u p p l i e d a r e i n c o m p l i a n c e w i t h t h e r e q u i r e m e n t s o f t h e L i s t o f P r o h i b i t e d S u b s t a n c e sNotes :- All pipes should be installed STRESS FREE to the compressor unit.- For more information concerning air nets, cooling systems, etc refer to the compressor installation manual.VENTILATION PROPOSALSALT. 1ALT. 2ALT. 3ALT. 41400Minimum free area to be reserved for the compressor installation8003459ATLAS COPCO STANDARD CLASS VIEW A100014008130090012671011213. Make sure the air intake of the compressor is always clean and no water droplets are present. Maximum acceptable relative humidity per ambient temperature100% RH 35 (95 F) 70%RH 40 (104 F) 30%RH 46 (115 F)1。
Henny PennyPressure Fryers压力炸锅Model/型号 500Model/型号561Model/型号 600OPERATOR’SMANUAL操作手册FM07-07003-10-05This manual should be retained in a convenient location for future reference.本手册应保存在方便的地方以供日后参考A wiring diagram for this appliance is located on the rear shroud cover of the control panel.线路图位于控制面板下的门里面Post in a prominent location, instructions to be followed if user smells gas. This informationshould be obtained by consulting the local gas supplier.安全指引应于醒目处张贴,当使用者闻到燃气时应严格按照安全指引操作。
向当地燃气供就供应商索取相关信息D o not obstruct the flow of combustion and ventilation air. Adequate clearance must be left alla round appliance for sufficient air to the combustion chamber. 请勿堵塞燃烧和换气的气流。
炸锅周围须留有足够空间保证燃烧室有充分的空气供给Keep appliance area free and clear from combustibles. 本炸锅应远离易燃物品adjustment, alteration, service, or maintenance can cause property Improperinstallation,damage, injury, or death. Read the installation, operating, and maintenanceinstructions thoroughly before installing or servicing this equipment. 不正确的安装、调节、改造、维修或保养可能引发财产损失、伤害或死亡。
VCOMB 4206© Rolls-Royce plc 2023The information in this document is the property of Rolls-Royce plc and may not be copied, orcommunicated to a third party, or used, for any purpose other than that for which it is supplied withoutthe express written consent of Rolls-Royce plc. Whilst this information is given in good faith based uponthe latest information available to Rolls-Royce plc, no warranty or representation is given concerningsuch information, which must not be taken as establishing any contractual or other commitment bindingupon Rolls-Royce plc or any of its subsidiary or associated companies.Proven powerInitially developed to create a turbofan member of theAE common core family for the growing regional jet andmedium/large business jet markets, further developmentcreated a growth version of military aircraft applications.To date, the AE 3007 has surpassed 65 million engineflight hours across defence and civil fleets.The AE 3007 turbofan core is derived from theAE 1007C-Liberty engine and is in the 8,000 lbf thrustclass. The AE 3007 turbofan engine is a high bypass, twoshaft engine.The engine features a wide-chord single-stage lowpressure (LP) compressor , 14-stage high pressure (HP)compressor , an effusion-cooled annular combustor , twostage high pressure HP) turbine and a three stage lowpressure (LP) turbine.Powering the Northrop Grumman RQ-4A Global Hawk • A single AE 3007H engine allows the Northrop Grumman R-Q4A Global Hawk to fly at over 65,000ft.• It provides the fuel efficiency required and the electrical power necessary to fly surveillance missions over 30 hours.• The system has already proven itself over the skies of Afghanistan and Iraq.A high-altitude, unmanned aircraft • The Northrop Grumman Triton is also powered by a single Rolls-Royce AE 3007H engine.• The AE 3007H provides the power to fly surveillance missions up to 24 hours at altitude over 10 miles high.• The Triton is specially designed to allow coverage out to 2,000 nautical miles, our engine provides the fuel efficiency and electrical power .Powering the Embraer 145• Two AE 3007A1P engines power the Embraer 145 Special Version aircraft used for intelligence, reconnaissance and surveillance missions.Thrust lbf: AE 3007H 9,500 (42) AE 3007A1E 8,895 (40) AE 3007A1P 8,338 (37) AE 3007A1 7,580 (33) AE 3007A1/3 7,580 (33)Bypass ratio 5.0 I Pressure ratio 23 I Length in (m) 115.08 (2.92)Fan diameter in (m) 38.5 (0.98) I Basic weight lb (Kg) 1,644 (746) Compressor 1LP , 14HP I Turbine 2HP , 2LP。
容积式压缩机positive displacement compressor往复式压缩机(活塞式压缩机)reciprocating compressor 回转式压缩机rotary compressor滑片式压缩机sliding vane compressor单滑片回转式压缩机single vane rotary compressor滚动转子式压缩机rolling rotor compressor三角转子式压缩机triangle rotor compressor 多滑片回转式压缩机multi-vane rotary compressor滑片blade旋转活塞式压缩机rolling piston compressor 涡旋式压缩机scroll compressor涡旋盘scroll固定涡旋盘stationary scroll, fixed scroll驱动涡旋盘driven scroll, orbitingscroll斜盘式压缩机(摇盘式压缩机)swash plate compressor斜盘swash plate摇盘wobble plate螺杆式压缩机screw compressor单螺杆压缩机single screw compressor阴转子female rotor阳转子male rotor主转子main rotor闸转子gate rotor无油压缩机oil free compressor膜式压缩机diaphragm compressor活塞式压缩机reciprocating compressor单作用压缩机single acting compressor双作用压缩机double acting compressor双效压缩机dual effect compressor双缸压缩机twin cylinder compressor闭式曲轴箱压缩机closed crankcasecompressor开式曲轴箱压缩机open crankcasecompressor顺流式压缩机uniflow compressor逆流式压缩机return flow compressor干活塞式压缩机dry piston compressor双级压缩机compound compressor多级压缩机multistage compressor差动活塞式压缩机stepped piston compoundcompressor, differentialpiston compressor串轴式压缩机tandem compressor, dualcompressor截止阀line valve, stop valve排气截止阀discharge line valve吸气截止阀suction line valve部分负荷旁通口partial duty port能量调节器energy regulator容量控制滑阀capacity control slide valve 容量控制器capacity control消声器muffler联轴节coupling曲轴箱crankcase曲轴箱加热器crankcase heater轴封crankcase seal, shaft seal 填料盒stuffing box轴封填料shaft packing机械密封mechanical seal波纹管密封bellows seal转动密封rotary seal迷宫密封labyrinth seal轴承bearing滑动轴承sleeve bearing偏心环eccentric strap滚珠轴承ball bearing滚柱轴承roller bearing滚针轴承needle bearing止推轴承thrust bearing外轴承pedestal bearing臼形轴承footstep bearing轴承箱bearing housing止推盘thrust collar偏心销eccentric pin曲轴平衡块crankshaft counterweight,crankshaft balance weight曲柄轴crankshaft偏心轴eccentric type crankshaft曲拐轴crank throw typecrankshaft连杆connecting rod连杆大头crank pin end连杆小头piston pin end曲轴crankshaft主轴颈main journal曲柄crank arm, crank shaft曲柄销crank pin曲拐crank throw曲拐机构crank-toggle阀盘valve disc阀杆valve stem阀座valve seat阀板valve plate阀盖valve cage阀罩valve cover阀升程限制器valve lift guard阀升程valve lift阀孔valve port吸气口suction inlet压缩机气阀compressor valve 吸气阀suction valve排气阀delivery valve圆盘阀disc valve环片阀ring plate valve 簧片阀reed valve舌状阀cantilever valve 条状阀beam valve提升阀poppet valve菌状阀mushroom valve 杯状阀tulip valve缸径cylinder bore余隙容积clearance volume附加余隙(补充余隙)clearance pocket活塞排量swept volumepiston displacement理论排量theoretical displacement实际排量actual displacement实际输气量actualdisplacement,actualoutput of gas气缸工作容积workingvolume of the cylinder活塞行程容积pistondisplacement气缸cylinder气缸体cylinder block气缸壁cylinder wall水冷套water cooled jacket气缸盖(气缸头)cylinderhead安全盖(假盖)safety head假盖false head活塞环piston ring气环sealing ring刮油环scraper ring油环scrape ring活塞销piston pin活塞piston活塞行程piston stroke吸气行程suction stroke膨胀行程expansion stroke压缩行程compressionstroke排气行程discharge stroke升压压缩机boostercompressor立式压缩机verticalcompressor卧式压缩机horizontalcompressor角度式压缩机angular typecompressor对称平衡型压缩机symmetrically balancedtype compressorcapacity of acompressor输气量standard capacity标准输气量rotational speed旋转速度outer dead point外死点inner dead point内死点stroke行程stroke volume行程容积swept volume 扫气容积clearance volume余隙容积relative clearancevolume相对余隙容积work volume/cylindervolume工作容积、气缸容积balancing volume平衡容积stroke bore ratio行程缸径比crank radius 曲柄半径length of connecting rod连杆长度ratio of crank radius to length of connecting rod连杆比mean piston speed活塞平均速度coefficient of capacity容积效率、输气系数pressure coefficient压力系数indicator diagram指示图mean indicated effective pressure平均指示压力piston rod load活塞力crank rotation angle曲柄转角piston rod load diagram活塞力图tangential force切向力normal force法向力mean tangential force平均切向力end bearing端轴承location bearing定位轴承distance piece中体tail piece端体counterweight平衡重oil retainer阻油圈oil slinger甩油环oil slinger ring挡油盘oil dipper溅油杆frame机身crankcase曲轴箱oil pan油底壳breather呼吸器main bearing主轴承main bearing liner主轴瓦main bearing cap主轴承盖connecting rod连杆crankpin bearing连杆轴瓦connecting rodcap连杆大头盖connecting rodbushing连杆小头衬套connecting rod body连杆杆身master and articulatedconnecting rod主副连杆crosshead十字头crosshead shoe十字头滑板crosshead pin十字头销crosshead guide十字头滑道floating crossheadpin浮动十字头销crosshead pinbushing十字头销衬套piston rod活塞杆through pistonrod贯穿活塞杆disk piston盘形活塞trunk piston筒形活塞conic piston锥形活塞differential piston级差活塞labyrinth piston迷宫活塞composite piston组合活塞plunger柱塞piston pin活塞销floating piston pin浮动活塞销piston pin bushing活塞销衬套piston ring活塞环compression ring气环oil ring油环rider ring导向环,支撑环cylinder气缸differential cylinder级差气缸power cylinder动力缸cylinder block缸体cylinder head缸盖cylinder liner缸套clearance valve余隙阀clearance cylinder余隙缸valve cage阀罩Specification 技术条件Bare compressor主机Reciprocatingcompressor往复式压缩机Compressed medium介质Stage级Throw列Bare compressor主机Driver原动机,驱动机Auxiliary equipment附属设备Frame and movingparts机体部分Liquid injectingcooling喷液冷却Ideal compressor理想压缩机Crankshaft pistonreciprocatingcompressor曲轴活塞压缩机Reciprocating compressorwithoutcrankshaft无曲轴压缩机Shaft pistoncompressor轴活塞压缩机Diaphragmcompressor膜片压缩机Gas compressor气体压缩机Air compressor空气压缩机Process compressor工艺流程用压缩机Compressor for shippurpose船用压缩机Fillingcompressor冲瓶用压缩机Motor compressor摩托压缩机Integral compressor 整体压缩机Minitype compressor 微型压缩机Stationary compressor 固定式压缩机Portable compressor 移动式压缩机Skid mounted compressor 撬装式压缩机No-foundation compressor 无基础压缩机Water-cooled compressor 水冷压缩机Air-cooledcompressor空冷压缩机Mixed cooling compressor 混冷式压缩机compressor with crosshead有十字头式压缩机compressor without crosshead无十字头式压缩机performanceparameter性能参数constructionalparameter结构参数suction pressure进气压力discharge pressure 排气压力rated pressure 额定压力nominal pressure 名义压力,公称压力stage pressure ratio级压力比overall pressure ratio总压力比pressure loss压力损失actual pressure实际压力capacity排气量channel valve槽状阀dish valve碟状阀multistoried valve多层阀ring valve环状阀disk valve网状阀leaf valve条状阀mushroom valve菌状阀combined valve组合阀direct-flow valve直流阀reed valve舌簧阀flap valve舌簧阀cushion valve气垫阀valve stop/valve guard升程限制器cushion plate缓冲片damper plate缓冲片guide plate导片valve spring气阀弹簧oil wiper packing刮油器packing case填料盒stuffing填函pre-stuffing前置填函mounting pad安装垫packing ring密封环oil wiper ring刮油环equalizing ring均压圈rectangle packing平面调料tapered packing梯形填料packing gland填料压盖diaphragm膜片base plate基座capacity of a compressor输气量standard capacity标准输气量rotational speed旋转速度outer dead point外死点inner dead point内死点stroke行程stroke volume行程容积swept volume 扫气容积clearance volume余隙容积relative clearance volume相对余隙容积work volume/cylinder volume工作容积、气缸容积balancing volume平衡容积stroke bore ratio行程缸径比crank radius 曲柄半径length of connecting rod连杆长度ratio of crank radius to length of connecting rod连杆比mean piston speed活塞平均速度coefficient of capacity容积效率、输气系数pressure coefficient压力系数indicator diagram指示图mean indicated effective pressure平均指示压力piston rod load活塞力crank rotation angle曲柄转角piston rod load diagram活塞力图tangential force切向力normal force法向力mean tangentialforce平均切向力end bearing端轴承location bearing定位轴承distance piece中体tail piece端体counterweight平衡重oil retainer阻油圈oil slinger甩油环oil slinger ring挡油盘oil dipper溅油杆frame机身crankcase曲轴箱oil pan油底壳breather呼吸器main bearing主轴承main bearing liner主轴瓦main bearing cap主轴承盖connecting rod连杆crankpin bearing连杆轴瓦connecting rodcap连杆大头盖connecting rodbushing连杆小头衬套connecting rodbody连杆杆身master and articulatedconnecting rod主副连杆crosshead十字头crosshead shoe十字头滑板crosshead pin十字头销crosshead guide十字头滑道floating crossheadpin浮动十字头销crosshead pinbushing十字头销衬套piston rod活塞杆through pistonrod贯穿活塞杆disk piston盘形活塞trunk piston筒形活塞conic piston锥形活塞differential piston级差活塞labyrinth piston迷宫活塞composite piston组合活塞plunger柱塞piston pin活塞销floating pistonpin浮动活塞销piston pinbushing活塞销衬套piston ring活塞环compression ring气环oil ring油环rider ring导向环,支撑环cylinder气缸differential cylinder级差气缸power cylinder动力缸cylinder block缸体cylinder head缸盖cylinder liner缸套clearance valve余隙阀clearance cylinder余隙缸valve cage阀罩Specification 技术条件Bare compressor主机Reciprocatingcompressor往复式压缩机Compressed medium介质Stage级Throw列Bare compressor主机Driver原动机,驱动机Auxiliaryequipment附属设备Frame and moving parts机体部分Liquid injecting cooling喷液冷却Ideal compressor理想压缩机Crankshaft piston reciprocating compressor曲轴活塞压缩机Reciprocating compressor withoutcrankshaft无曲轴压缩机Shaft piston compressor轴活塞压缩机Diaphragmcompressor膜片压缩机Gas compressor气体压缩机Air compressor空气压缩机Process compressor 工艺流程用压缩机Compressor for ship purpose船用压缩机Fillingcompressor冲瓶用压缩机Motor compressor 摩托压缩机Integral compressor 整体压缩机Minitype compressor 微型压缩机Stationary compressor 固定式压缩机Portable compressor 移动式压缩机Skid mounted compressor 撬装式压缩机No-foundation compressor 无基础压缩机Water-cooled compressor 水冷压缩机Air-cooledcompressor空冷压缩机Mixed cooling compressor混冷式压缩机compressor withcrosshead有十字头式压缩机compressor withoutcrosshead无十字头式压缩机performanceparameter性能参数constructionalparameter结构参数suction pressure进气压力discharge pressure 排气压力rated pressure 额定压力nominal pressure名义压力,公称压力stage pressureratio级压力比overall pressureratio总压力比pressure loss压力损失actual pressure实际压力capacity排气量channel valve槽状阀dish valve碟状阀multistoried valve多层阀ring valve环状阀disk valve网状阀leaf valve条状阀mushroom valve菌状阀combined valve组合阀direct-flow valve直流阀reed valve舌簧阀flap valve舌簧阀cushion valve气垫阀valve stop/valveguard升程限制器cushion plate缓冲片damper plate缓冲片guide plate导片valve spring气阀弹簧oil wiper packing刮油器packing case填料盒stuffing填函pre-stuffing前置填函mounting pad安装垫packing ring密封环oil wiper ring刮油环equalizing ring均压圈rectangle packing平面调料tapered packing梯形填料packing gland填料压盖diaphragm膜片base plate基座压缩机英语术语Type of compressor 压缩机类型1. positive displacement compressor 容积式(正位移)压缩机1) reciprocating compressor 往复式压缩机2) piston compressor活塞式压缩机3) plunger compressor柱塞式压缩机4) diaphragm compressor 隔膜式压缩机5) rotary compressor回转式压缩机6) double screw compressor 双螺杆压缩机7) single screw compressor单螺杆压缩机8) rolling piston compressor 滚动活塞式压缩机9) sliding vane compressor 滑片式压缩机10) liquid ring compressor 液环式压缩机11) triangle rotor compressor 三角转子压缩机12) scroll compressor 涡旋式压缩机13) Roots blower 罗茨鼓风机2.dynamic compressor 动力式压缩机1) turbo compressor 透平压缩机2)centrifugal compressor 离心式压缩机3) axial flow compressor 轴流式压缩机Reciprocating compressor 往复式压缩机基本概念1) compressed medium 压缩介质(介质、工质)——被压缩的工质(气体)2) stage 级——完成压缩循环的基本单元3) 段——在一台工艺流程用压缩机中,相邻各级的气量和组分相同时,称为段4) line (row) 列——在同一气缸轴线上的单个气缸或串联气缸,结构上组成一列5) bare compressor 主机——压缩机的机体部分和压缩部分的总称6) driver 驱动机(原动机)——驱动压缩机的动力机械或装置7) auxiliary equipments 附属设备(辅机)——除主机和驱动机外,其余设备的总称8) frame and moving parts机体部分(基础部分)——压缩机的机身或曲轴箱和运动部件等的总称9) compressing components压缩部分(气缸部分)——压缩机的气缸、活塞、气阀和填料函等部件的总称10) variable-type 变型——对原型机的结构作局部变更,在其型号中标有“结构差异”者,称为原型机的变型11) variant 派生——原型机的机体部分基本不变或其型号中的“结构”不变,而“特征”和(或)性能参数及特性或介质改变者,称为原型机的派生12) inter-cooling 中间冷却(级间冷却)——导走级间压缩介质的热量13) after coling 后冷却——导走完成压缩后的压缩介质的热量14) liquid injection cooling喷液冷却——向压缩介质中喷液以降低介质温度15 ideal compressor 理想压缩机——无余隙容积、无泄漏、亦无压力损失现象的压缩机types 分类1. crankshaft pistoncompressor 曲轴活塞压缩机(活塞压缩机)——具有曲轴旋转运动的压缩机2. reciprocating compressorwithout crankshaft 无曲轴压缩机(无轴压缩机)——没有曲轴或轴的旋转运动的压缩机3. shaft piston compressor 轴活塞压缩机(斜盘压缩机)——活塞轴线平行于动力输入轴轴线,且均布于其周围的压缩机4. diaphragm compressor 隔膜压缩机(膜片压缩机)——机械直接或液压驱动膜片,完成压缩循环的压缩机5. gas compressor 气体压缩机(压气机)——压缩介质除空气外的其他气体,也可包括空气的压缩机之统称6. air compressor 空气压缩机(压风机)——压缩机介质为空气的压缩机7. general purposecompressor/all purposecompressor/compressor forpressed air/pressed–aircompressor 动力用压缩机——为气动机械和气动工具提供动力气源的压缩机8. process compressor 工艺流程用压缩机(流程压缩机)——石油、化工等工艺流程用的压缩机9. compressor for ship purpose 船用压缩机——专用于舰船的压缩机10. filling compressor 充瓶用压缩机(充瓶压缩机)——用于压缩介质装瓶的压缩机11. multi–purpose compressor/multi–service compressor 联合压缩机——同一台压缩机中,各气缸分别压缩多种工质且非前后级关系的压缩机12. combined compressor/combination compressor复合压缩机(串联压缩机)——同一压缩机中,分别采用不同类型的压缩机,形成前后级关系,达到提高介质压力的压缩机13. motor compressor/gas–engine compressor 摩托压缩机14. integral compressor/motor compressor 整体压缩机(摩托压缩机)——与往复式原动机部分地共用一个运动机构的压缩机。
压力和压强的英语单词:pressure /ˈpreʃə(r)/ ;stress /stres/英语释义:- pressure: the force applied to a surface per unit area.- stress: pressure or tension exerted on a material object.短语:1. under pressure 在压力下2. high pressure 高压3. pressure cooker 高压锅4. blood pressure 血压5. stress management 压力管理6. stress out 使紧张7. stress test 压力测试8. working pressure 工作压力9. put stress on 强调10. relieve stress 缓解压力用法:- “pressure” 可表示物理上的压力,也可用于表示心理、社会等方面的压力。
- “stress” 更侧重于精神、心理方面的压力或紧张状态。
双语例句:1. The gas pressure is very high.(气体压力非常高。
)2. He is under a lot of pressure at work.(他工作上有很大压力。
)3. The water exerts pressure on the dam.(水对大坝施加压力。
)4. She is feeling the stress of the exam.(她感受到考试的压力。
)5. Don't stress too much about it.(别对此过于紧张。
)6. Thepany is facing high pressure to increase profits.(公司面临提高利润的巨大压力。
)7. He cracked under the stress.(他在压力下崩溃了。
PRODUCTION TECHNICAL TRAINING生产培训PRESENTS课程介绍MODULE: Compressors模块:压缩机DESIGNED FORENHANCING OPERATIONS KNOWLEDGE & SKILLS适用于提高操作知识和技能STUDENT PACKAGE学生部分TABLE OF CONTENTS目录If viewing this TOC on a computer, you can move directly to a subject area by pointing with your cursor and single clicking.如果要在计算机上观察这种TOC(目录表),你可以利用光标指点和单击,直接移动到主题区。
I.INTRODUCTION: (6)I.引言II.GAS COMPRESSION AND METHODS OF COMPRESSION (6)II.气体压缩和压缩方法A.C OMPRESSION B ASICS (6)A.压缩基本知识1)Gas Physics (6)1) 气体的物理性质2)Centrifugal Compressor Head Curve (7)2)离心式压缩机压头曲线B.P URPOSES OF C OMPRESSING G AS IN C HEMICAL P ROCESS S YSTEMS (7)B.化学工艺系统中压缩气体的目的C.C OMMON T YPES OF C OMPRESSORS AND T HEIR O PERATION (8)C.常用类别的压缩机及其运转III.CENTRIFUGAL AND AXIAL FLOW COMPRESSORS (9)III. 离心和轴流压缩机A.C ENTRIFUGAL C OMPRESSORS (9)A.离心压缩机1)Uses (9)1)用途2)Major Components and Operation (10)2)主要零部件和运转B.A XIAL F LOW C OMPRESSORS (10)B.轴流压缩机1)Uses (10)1)用途2)Design and Operation (11)2)设计和运转C.C ENTRIFUGAL C OMPRESSOR S EALING/L UBRICATION AND C OMPONENTS..............C.离心压缩机密封/润滑和零部件1)Non-contact Shaft Seals (12)1)非接触轴封a)Labyrinth Seal (12)a)迷宫式密封b)Ported Labyrinth Seal (3)b)带排出孔的迷宫式密封c)Restrictive Ring Seal (4)c)阻流环密封2)Contact Shaft Seals (5)2)接触轴封a)Mechanical Contact Shaft Seal (5)a)机械接触轴封b)Liquid-Film Shaft Seal (6)b)液膜轴封c)Overhead Seal Tank (7)c)高位密封油箱3)Bearings (8)3)轴承a)Journal Bearing (9)a)支持轴承b)Thrust Bearing (9)b)推力轴承c)Tilting-Pad Journal Bearing (9)c)可倾瓦块支持轴承d)Balancing Drums (10)d)平衡盘4)Lube-Oil Systems (13)4)润滑油系统D.C OMMON O PERATING P ROBLEMS IN C ENTRIFUGAL AND A XIAL F LOW C OMPRESSORS C OMPRESSORS (15)D.离心和轴流压缩机的常见运转问题1)Surge Problems (15)1)喘振问题a)Causes of Surge (15)a)喘振原因b)Methods of Correcting Surge (16)b)纠正喘振的方法2)Vibration Problems (16)2)振动问题a)Definitions and General Physics (17)a)定义和一般物理性质b)Monitoring Systems (20)b)监视系统c)Radial Vibration (21)c)径向振动d)Axial Displacement (22)d)轴向位移e)Temperature (23)e)温度f)Vibrating Alarm Systems (23)f)振动报警系统g)Transducer-Failure Alarm (24)g)传感器故障报警h)High-Radial-Vibration Alarm (24)h)大径向振动报警i)Axial-Position Alarm (24)i)轴向位移报警j)High-Temperature Alarm (24)j)高温报警3)Lube and Seal-Oil Systems and Problems (25)3)润滑和密封油系统及问题a)Typical Lube Oil System (25)a)典型的润滑油系统b)Typical Seal Oil System (28)b)典型的密封油系统IV.POSITIVE DISPLACEMENT COMPRESSORS (30)IV. 容积式压缩机A.R ECIPROCATING C OMPRESSORS (30)A.往复式压缩机1)Design Characteristics (30)1)结构特点2)Double-Acting Reciprocating Compressor (39)2)双作用往复式压缩机3)Operation (39)3)操作B.R OTARY C OMPRESSORS (40)B.旋转式压缩机1)Rotary Sliding Vane Compressors (40)1)旋转滑动叶片压缩机2)Rotary Two-Impeller (Lobed) Compressors (41)2)旋转式双叶轮(叶形轮)压缩机3)Rotary Screw Compressor (42)3)旋转式螺杆压缩机4)Rotary Liquid Piston Compressors (43)4)旋转液体活塞压缩机VI.SUMMARY (47)VI.摘要I.INTRODUCTION:引言Compressors are similar in construction to pumps, but operate on different principles since gases are compressible and liquids are not. The primary purpose of compressors is to move air or gases from one place to another and to increase its pressure. Centrifugal and reciprocating compressors are found in many plants. As a Technician, you must be familiar with the design and basic operation of these pieces of equipment and how gases behave when they are compressed.压缩机的结构与泵的类似,但以不同的原理运转,原因是气体可压缩,但液体不能。
CHAPTER7VERY HIGH PRESSURECOMPRESSORS(over100MPa[14500psi])Enzo GiacomelliGeneral Manager Reciprocating CompressorsNuovo PignoneAlessandro TraversariGeneral Manager Rotating MachineryNuovo Pignone7.1DESIGN PROCEDURE7.1.1General Information on High Pressure ServicesThe mechanical difficulties connected with high pressures were encountered bycompressor manufacturers during the development of ammonia synthesis processesafter1920,as pressures of about100MPa(14500psi)were reached.Subsequently,the ammonia synthesis process was developed by reducing the final pressure and today’s values are around32MPa(4640psi).Other applicationssuch as Urea production required pressure up to35MPa(5075psi),but today,dueto improvement in the process,reaction can be obtained at pressures of15to20MPa(2175-2900psi).The storage and reinjection of natural gas also use highpressures ranging between15and60MPa(2175to8700psi).Each applicationhas particular difficulties connected to gas compression,liquid carry over,lubri-cation and corrosion.The use of high pressure processes increased after World War II with industrial demand for low density polyethylene(LDPE),1whose polymerization is achievedby bringing the gas up to350MPa(50750psi)by using special types of recipro-cating compressors(Fig.7.1).Compressors in this service have been given thename hypercompressor.7.17.2CHAPTER SEVENFIGURE7.112cylinder compressor for very high pressures(courtesy of Nuovo Pignone).Plant capacities have considerably increased.In the early1960s,the normal production per single line was on the order of7,000t/yr,*while lines producing200,000t/yr LDPE are now in operation.These plants are dangerous in case of erroneous or unsafe operation,because of the highflammability of the gas and the very high pressures involved in the pro-duction process.One of the sources of risk is to be found in the secondary hypercompressor, where two main areas called for special care in the design and manufacturingstages:parts subjected to pressure and the crankgear.The cylinders are subject to pressurefluctuations,which can cause fatigue failure if design,manufacture and material selection are not adequate.The crank mechanism,driving the plungers,must perform its task with great accuracy,because any misalignment might cause failure2with possible risk offire.Plungers are in fact brittle items owing to the very hard metal used,generally solidtungsten carbide.As a consequence,the design of these machines must be based on sound fun-damental choices3and supported by the most up to date analysis methods andexperimental techniques.4VERY HIGH PRESSURE COMPRESSORS7.3 Polyethylene types,differing in molecular weight,density,and degree of crys-tallization,can be divided into two categories depending on the process used to polymerize the ethylene:•High Density Polyethylene(HDPE)is obtained with a low-pressure process, working at pressures below5MPa(725psi)and giving a product with density ranging from0.945to0.970g/cm3(.034–.035lb/in3).•Low Density Polyethylene(LDPE),produced by high-pressure processes,oper-ating between100and350Mpa(14500–50750psi),gives a product with a little lower density(0.91to0.93g/cm3)(.033–.034lb/in3).The introduction of low pressure processes producing Linear Low Density Pol-yethylene(LLDPE)with operating pressures below2MPa(290psi)began to erode the sectors served by LDPE,reaching today plant capacities up to500,000t/yr of polyethylene.The possibility of obtaining linear polyethylene with high pressure(HPLLDPE) was then investigated and practical applications were found in some existing plants withfinal pressures from80to170MPa(11600to24650psi),in order to provide some operatingflexibility.Since the polymerization of these products requires the machine to operate in very difficult conditions,the process is now applied only in existing plants.Although extremely good results were obtained with plastic sealing elements on the packings,the difficulty of controlling the process,in general,the severe lubri-cating conditions and the presence of aluminalkyle were resulting in unreliable performance.About50%of the new plants for Low Density Polyethylene today are built to use compressors to bring ethylene to high pressure and then subject the gas in a reactor to temperature and a catalyst.The polymer formed has good mechanical and optical properties.Furthermore,these processes have no environmental impact, as they contain no metals and involve only ethylene and energy.This technology is simple to use,competitive and offers possibilities for devel-opment of catalysts such as the‘‘metallocenic’’ones,wellfitting with homogeneous systems(like the high pressure LDPE).At present,high pressure polyethylene production covers the following sectors:ProductDensityg/cm3(lb/in3)GasPressureMPa(psi)LDPE0.920(.033)ethylene120–350(17400–50750) Copolymers10.927–0.935(.033–.034)ethyleneϩvinylacetate(5to40%)120–350(17400–50750) Copolymers20.927–0.935(.033–.034)ethyleneϩacrylates120–350(17400–50750) HPLLDPE0.880–0.920(.032–.033)ethyleneϩbutylene(10to40%)80–150(11600–21750)7.4CHAPTERSEVENFIGURE 7.2Special crank mechanismwith self-aligned high pressure cylindersdirectly connected to the frame.Although low pressure processes are continuously improving,with the help of special catalysts,the high pressure process will still be needed in future.7.1.2Features of the Machines for LDPE ServicesThese pressures are reached by reciprocating compressors,having special design and using advanced materials such as NiCr-Mo steels vacuum melted and sintered tungsten carbide.For safety and reliability of operation,the following aspects need to be faced:•The fatigue of the components subject to fluctuating pressure between suction and discharge•The sliding seal,between piston and cylinder•The definition of a crankmechanism capable of giving perfect linear movement of the pistons•The risks connected with the gas in the polymerization of ethyleneThe proper design of very high pressure machines requires investigation of ther-modynamic,mechanical,process,operational and safety aspects.5As an example,the motion work (Fig.7.2),should drive the plungers with absolute precision.The crosshead movement should be perfectly straight and coincide with the cylinder axis under both cold and warm conditions.The thermal expansion of the crosshead should not affect alignment.Both planes of the vertical and horizontal guides should pass through the centerline of the plunger,which is centered to the crosshead without clamping and is supported by the packing bush in the cylinder.The cylinders (Fig.7.8),which are directly connected to the frame,require partic-ular care in the design of parts subject to gas pressure and of the seal arrangement.Poppet type valves should be sized to minimize fluttering phenomena that would damage both the seat and the poppet.Solid tungsten carbide or plated plungers are used with bronze or very special plastic packing,depending on the process and pressure.VERY HIGH PRESSURE COMPRESSORS7.5FIGURE 7.3Crankgear using conven-tional and auxiliary crossheads.For reasons of safety,a distance piece is inserted in the cylinder arrangement.A first recovery vent connected to flare or safe area,an oil barrier used to cool the plunger,and an emergency vent allow for proper gas leakage control without en-tering into the crankcase.Should gas enter the frame in emergency conditions,relief valves are provided.Nitrogen purging of the crankcase to eliminate oil vapor mixtures ensures safe operation.7.1.3Crankgear ArrangementsFor structural reasons,it is preferred the cylinders be of the single acting type.The thrust mechanism of each plunger is subjected to a unidirectional load with diffi-culty of lubricating the load bearing connections,where surfaces always remain in contact,without the possibility of establishing an oil film (for example,between the small end of the connecting rod and the crosshead pin.)In the design of the crank-mechanism for polyethylene compressors,various compressor manufacturers have used different solutions to resolve the problem of the linear transmission of movement and the unidirectional load.•The conventional type of crosshead drives through a spherical coupling an aux-iliary crosshead (Fig.7.3),in order to reduce the oscillation transmitted to the plunger,but does not provide reversal of load on the small-end bearing.This bearing must be sized with low specific loading to allow for conditions of pre-carious lubrication and the transient state between liquid film lubrication and dry friction.•An external auxiliary crosshead (Fig.7.4)is driven by the main crosshead through tie bolts.Opposed plungers are attached to this auxiliary crosshead (yoke).With this construction,the thrust reversal is met and oscillation due to the low friction force acting on it is reduced by the auxiliary crosshead .The problem of thermal expansion might still exist,but the solution for this is to locate the main and auxiliary crossheads in different frames,at some distance apart.Accessibility of the inside cylinder may still be somewhat restricted in this type machine.7.6CHAPTERSEVENFIGURE 7.4Crankgear with main crossheads connected toauxiliary crossheads in separateframe.FIGURE 7.5Crankgear using two spe-cial crossheads with tie bolts and auxiliarycrossheads.•Another solution is to utilize a hydraulic device for the transmission of force to the piston.This is able to provide capacity variations,give perfect linear move-ment to the pistons,and also may have a complete oil control circuit.•Two special crossheads (Fig.7.5),one directly attached to the connecting rod,the other positioned on the opposite side of the crankshaft,connected by tie bolts,satisfy the thrust reversal requirement.Auxiliary crossheads are required to avoid transmitting to the pistons oscillations and to absorb the thermal expansion of the main crosshead.This expansion is a function of the distance between the crosshead pin and sliding surfaces and causes a displacement between the axis of the crosshead with respect to the axis of the cylinder.•Another special arrangement (Fig.7.6)has a crosshead,with sliding surfaces and guides in the lower part of the frame.Two connecting rods are used on each side.Thrust reversal is ensured by having two plungers on opposite sides of the main crosshead.In order to obtain adequate linear movement during operation,an auxiliary crosshead is necessary to eliminate the thermal expansion resulting from the distance between plunger and main crosshead guides.VERY HIGH PRESSURE COMPRESSORS 7.7FIGURE 7.6Special crosshead with twoconrods and with auxiliarycrossheads.FIGURE 7.7Special crosshead self-aligned as-sembly,adopted for secondary compressors inLDPE Plants.•A special and precise solution (Fig.7.7),with two opposed plungers,is driven through a special crosshead,within which rotate crankshaft and connecting rod.The crosshead guides are plain and their axis is placed on the centre-line.The distance between crosshead slides is long,with a small clearance,and thus mis-alignment due to thermal expansion is avoided as the plunger axis and the slides are on the same plane.This patented solution 5meets the above requirements most satisfactorily.As a result,the movement of this crosshead is perfectly straight-line and coinciding with cylinder axis under both cold and warm conditions.In fact:•Pitching is mechanically prevented by the very small clearance ratio between guide and wing and distance between the guides and also because the friction force on the slides practically coincides with the gudgeon pin axis;•Thermal expansion of the crosshead does not affect alignment,as the two planes of the vertical and horizontal guides pass through the plunger center-line.7.8CHAPTERSEVENFIGURE 7.8Cylinder with radial valves.This solution avoids the use of auxiliary crossheads which are necessary when a conventional main crosshead is used,to correct its rocking movement.Auxiliary crossheads make the machine longer,more complicated,more difficult to align and,above all,they do not allow the cylinders to be directly connected to the frame,to eliminate the need for external support.This condition is in fact fundamental to building a machine which is really ‘‘factory aligned’’and needs no realignment in the field.The last two solutions are the only ones still applied in new plants.7.1.4Characteristics of CylindersAs they work at very high pressures,hypercompressors should incorporate features to make them safe,reliable,and efficient.5The cylinders,connected by long hydraulically-tightened tie rods,consist of three major parts:a flange connecting the cylinder to the motionwork frame,the main packing housed in a cartridge assembly,and the cylinder head containing suction and discharge valves.The cylinder with radial valve arrangement (Fig.7.8)is a typical structure with a compression chamber,and a plunger with packing for gas sealing.Packing cup geometries are complex,as housings are provided for guide bushes and seal rings,and also because of the presence of lube oil holes.Similar cylinder arrangements are used with high pressures over 230–250MPa (33350to 36250psi),where the cylinder head will have axial valves (Figs.7.9and7.10).36VERY HIGH PRESSURE COMPRESSORS7.9FIGURE 7.9Axial valve cylinderhead.FIGURE 7.10Multipoppet axial valve cylinder head.Construction with vertical or radial pipes-inlet and outlet (Fig.7.9)-allows better fastening to the foundation in order to obtain a very low vibration level.An ar-rangement with axial and radial pipe arrangement (Fig.7.10)is also used in relation to plant layout requirement.Valves of radial type (Fig.7.11)are used up to 250MPa (33350psi).Axial combined suction-delivery valves cover the entire operating pressure range with7.10CHAPTERSEVENFIGURE 7.11Radial valve assem-bly.FIGURE 7.12Axial combined valve assembly.monopoppet (Fig.7.12)or multipoppet (Fig.7.13)solutions.All valves are of the poppet type with gas velocity usually between 30and 60m/s (98to 197ft/sec).Experience indicates outstanding performance of radial valves with over 30,000hours of operation,due to the following advantages:FIGURE7.13Axial multipoppet valve as-sembly.Greater reliability•A very simple valve structure•Less possibility of polymer formation since the gas velocity is a little higher •Very low sticking effect on the poppet during operation because of higher clearance and higher drag force on the poppet•Larger diameter of springs gives greater enduranceBetter sealing•The machining of the seats is more difficult on multipoppet valves•The higher clearance on a monopoppet valve allows for a better contact be-tween seat and poppet with less possibility of damageMonopoppet valves have greater allowance for reconditioning after long oper-ation and are easy to assemble.On the axial valves,special seals separate the two sections from each other and from the outside.This solution serves a dual purpose by:Allowing precompression of the valve bodies with pressure outside them,so that their tensile stresses are minimized.Eliminating high stressfluctuations in the cylinder head at the suction and dis-charge crossbores.The areas of heads subjected to high stress work in a precompression state,when‘‘autofrettage’’is applied.Two-piece construction for compression chamber and packing cups is obtained by shrink-fitting to precompress the most highly-stressed areas.The cylinder heads have large holes intersected by lateral ducts for gas suction and discharge.Cylinder design is important in order to attain the goal of safety-reliability-performance.6It is necessary to solve problems connected with highfatigue stresses due to highfluctuating pressures and the variations in geometriescausing stress raisers.Variations in geometry are minimized to reduce the effects of stress concentra-tion.Surface roughness is very important from the fatigue point of view and specialmachining procedures are needed to obtain very high levels offinish.In case of acylinder head with radial valves,where the whole crossbored cylinder is subject topressures varying between suction and delivery,stressfluctuations must be evalu-ated at the critical points and adequate prestressing applied.The highest pressures require a solution with a combined suction-discharge valve,enabling reduction of stress concentration effects on the head by setting theintersection points at places where pressurefluctuation is low.In a cylinder for very high pressures,the material must also be efficiently ex-ploited by the use of prestress methods such as shrink-fitting and autofrettage,which ensure more uniform stress distribution across the cylinder wall.These twomethods may also be applied together when a high compressive prestress level isnecessary in order to operate safely.7.1.5Safety AspectsSafety is of great importance in LDPE plants on account of theflammability of thegas and the high pressures involved.The discharge temperature of the gas is limitedtoday to100to110ЊC*to reduce the risk of dissociation of ethylene in the cylinder,while in the past120ЊC was reached in single stage compressors.In this case,toensure lowfinal temperature,the gas was cooled before entering the cylinder.As a further precaution,the plant is usually installed in the open air,sometimes under roofing,or in well-ventilated enclosures to prevent any accumulation of gasdue to accidental leakage.For the safety of personnel,it is the practice of engineering and manufacturing companies to position the instrumentation and control equipment at some distancefrom the most hazardous parts of the plant,and to ensure appropriate managementand use of modern monitoring and automation systems.8Centralized control andoperation of the plant also allows optimization of process parameters and shorterperiods of transient operation,with even more outstanding performance of thewhole plant.Additional benefits derive from the application of monitoring systems with main-tenance based on predictive rather than preventive criteria.With modern materials and design techniques,reciprocating compressors in-cluding very high pressure units now reach very high safety levels with reliabilityand availability factors over99.5%.Special safety concepts are applied to compressors,as the plungers are very brittle and misalignment may produce failures.An intrinsically safe crank mecha-nism is of prime importance.7The plungers must always be kept free to rotate andto move axially and a special connection to crosshead(Fig.7.14)is required.Furthermore,the cylinder bolts must be long enough to permit elastic elongation in case of decomposition or overpressure in the cylinder.The head is lifted by theelastic stretching of the tie rods and the gas is released through special reliefchannels in the head itself.A separation chamber between cylinder and frame isdesigned to vent any excess ethylene leakage from packings to the atmosphere,thus preventing gas from entering the frame.Nitrogen purging is applied to theframe as in internal combustion engines.The material used for high pressures zonesis selected ductile enough to‘‘leak before breaking.’’7.2STRESS CONSIDERATIONS7.2.1Heavy-walled Cylinders Under PressureTypical arrangements of high-pressure cylinders of the plunger and packing types(Figs.7.8,7.9,and7.10)consist of cylindrical bodies,nearly symmetrical,such asFIGURE7.14Plunger—crosshead specialconnection.FIGURE 7.15Shear stress versus K ϭOD/ID ratio onheavy-wall cylinders.the cylinder head,where suction and delivery valves are housed,formed by the intersection of the central duct and the lateral ducts feeding the valves,the com-pression chamber and the packing cups.As all these areas are under pressures ranging from the value of suction to that of delivery,they are susceptible to fatigue.For the highest pressures,a solution utilizing a combined suction and discharge valve is employed.Stress concentration in the head is reduced by arranging these points of intersection at a position of low pressure fluctuation (Figs.7.9and 7.10).At the design stage,the target is to simplify the shape by reducing it as nearly as possible to a cylindrical form or,to the intersection of cylinders.This facilitates calculation and tends towards a safer design.Thick cylinders under internal pressure have distribution of stresses in the wall such that the radial stress (always in compression)has a value equal to the internal pressure and decreases to zero at the outside diameter,while the circumferential stress (always tensile)has a maximum value at the inside diameter and decreases to a value which remains above zero.Circumferential and shear stress cannot be reduced below the value of the internal pressure at the inner bore.This distribution is a disadvantage,as a small part of the cylinder wall is under high stress,the outer fibres being less loaded as evidenced by the trend of the shear stress per unit pressure (c ϩp )/p versus the OD/ID (outside diameter/inside diameter)ratio K (Fig.7.15).For values of K in excess of 2.5there is little advan-tage in increasing the wall thickness,and over 5the inside ideal stress is practically that of a cylinder with infinite wall thickness.FIGURE 7.16High pressure cylinder with WCliner and piston rings.To design cylindrical bodies for very high pressures,it is necessary to utilize the material more efficiently by using prestressing methods such as shrinkage or autofrettage,which result in a more uniform stress distribution across the wall.The simplest method of prestressing is compound shrinkage.It makes it possible to have the critical parts working at points that are more favourable on the endur-ance limit diagram,while the stress range will remain unchanged,depending on the total radial thickness only.Tungsten carbide liners (with a normal modulus of elasticity about three times that of steel)have been used inside the cylinder.These offer resistance to fatigue when the tungsten carbide is prestressed so that it is always in compression even under the most severe operating conditions.This construction was applied with piston rings as sliding seals,between piston and cylinder (Fig.7.16).Tungsten carbide has a low friction coefficient,great resistance to wear,and good resistance to corrosion.It is a suitable material for sliding seal elements under heavy contact pressure.The application of brittle wear resistant materials is important,although they are undesirable if highly stressed in high-pressure equipment because of the risk of fragmentation if they should fail.9The failure criterion for brittle materials is the maximum tensile stress,i.e.,when the liners are subjected to internal pressure greater than external pressure,the circumferential stress at the inner diameter has to be considered.The state of stress in any cylindrical body is worsened by the presence of radial holes,necessary in the cylinder for the suction and delivery of gas(in the heads),as well as for bringing lubricating oil to the sealing elements in the packing cups.In the intersection of the radial holes with the bore,the stress system10is com-posed of:cϭcircumferential stress at intersection of radial hole,with the bore due to the internal pressure in the bore and within the radial holeaϭaxial stress due to preload on the cylinder and effects of internal pressure within the radial holerϭradial stress caused by the internal pressures acting on the points of inter-section of the radial hole and the boreThe presence of cross-bores and the consequent stress concentration has a strong effect on the fatigue strength of cylinders.To reduce the risk of failure,the materialhas to be prestressed,inducing compressive stresses by shrinkage or autofrettage.The latter process consists of stressing one part of ring beyond the yield point of the material.A greater plastic deformation occurs on the inside of the cylinder.When the autofrettage pressure is released,a compressive stress results in the innerzone and a residual tensile stress in the outer part.This method is preferred toshrink-compounding in the presence of crossbored cylinders such as those used forhigh-pressure cylinder head and packing cup.Some tests11made on a cylinder with a ratio of2.25between OD and ID di-ameter,with the cylinder wall overstrained up to the geometric mean radius,showedit to be as strong after autofrettage as non-autofrettaged cylinders without stressconcentration.These results were obtained after applying pressure at least onemillion times.It is possible to use shrinking and autofrettage,thus obtaining theadvantage of a more uniform stress distribution across the total cylinder wall thick-ness,ensuring a safer component under working conditions.7.2.2General Design CriteriaMost of the analytical design considerations on the components of the cylindersare based on the traditional equations of stresses and strain related to a cylinderunder pressure.Therefore,the formulas needed to obtain the stress level and thedetermination of the point of failure can be found in the contributions of manyauthors.•Materials used in high pressure services are normally steel alloys with mechanicalproperties ranging from1000to1500MPa(145000–217500psi)UTS(UltimateTensile Strength).•Selection of materials is generally related to the stress level,as the corrosioneffects are negligible,apart from very special applications,where stress corrosionmay occur.FIGURE 7.17a Traction-compression Smith diagramfor NiCrMo steel.•When high stress levels are involved,Vacuum Remelted (Electroslag or Vacuum Arc Remelted)or superclean steels have to be used.•These features are very important because the inclusion level is very low and the risk of fatigue failures is strongly reduced.The characteristics of such materials with relevant endurance limits are reported on Fig.7.17a and 7.17b.The design of cylinder components has to make reference to thick walled cyl-inders under pressure,with the use of shrink-fitting construction,11autofrettage technique,12,13,14,15often applied to cross-bored cylinders 16,17,18generally under fa-tigue.19,20,21The initial contact pressures,between the various components of the cylinders,arising after preloading of the main bolts,should have a safety factor of 1.2against yield stress of the material.The preload is usually established by assuming contact pressure on two adjacent parts will come to a level 10to 20%above the internal pressure.Stress risers have to be accounted for when holes or changes in geometry are involved.The stress concentration factors are generally applied to the range part at the stress,without considering the mean stress level.Various methods could be applied to determine factor or safety.The basic ap-proach is to compare in a consistent way the stress level in operation with an allowable value,usually endurance or yield strength,for the material being used.FIGURE 7.17b Fatigue diagram of cross-bored cylinder(K ϭ3)with and without autofrettage,tested with internalpressure.A combined stress calculated for a cylinder component is usually based on the V on Mises criterion since almost always a triaxial stress state is generated by the complex loading of the cylinder components.Considering the fact that cyclic stress is made up of mean (m )and range (R )stresses,the conditions related to suction and discharge are reduced to a mean stress and a range stress and then combined in accordance to the criterion of V on Mises22ϭ(1/͙2)[(Ϫ)]ϩ(Ϫ)mises m c (mean)r (mean)r (mean)a (mean)21/2ϩ(Ϫ)](7.1)a (mean)c (mean)22ϭ(1/͙2)[(Ϫ)]ϩ(Ϫ␣)mises R c (range)r (range)r (range)a (range)21/2ϩ(Ϫ)](7.2)a (range)c (range)Safety factors are thus defined in respect to the Mises (mean )and the Mises (range )stresses as:。