能源与动力学院 毕业设计(论文)外文翻译皮

毕业设计外文翻译原文标题：Proposal for a high efficiency LNGpower-generation System utilizing wasteheat from the combined cycle中文标题:一个高效的利用液化天然气联合循环余热的发电系统学院名称：能源与动力工程学院专业名称：热能与动力工程Proposal for a high efficiency LNG power-generation system utilizing waste heat from the combined cycleY. Hisazumi*, Y. Yamasaki, S. SugiyamaEngineering Department, Osaka Gas Co., 1-2 Hiranomachi 4-chome Chuo-ku, Osaka 541, Japan Accepted 9 September 1998AbstractHigh-efficiency power-generation with an LNG vaporizing system isproposed: it utilizesthe LNG's cold energy to the best potential limit. This system can be applied to LNG vaporizers in gas companies or electric power companies and recovers the LNG's cold energy as electric power. The system consists of a Rankine cycle using a Freon mixture, natural-gas. Rankine cycle and a combined cycle with gas and steam turbines. The heat sources for this system are the latent heat from the steam-turbine's condenser and the sensible heat of exhaust gas from the waste-heat recovery boiler. In order to find out the optimal condition of the system, several factors, such as gas turbine combustion pressure, steam pressure, condensing temperature in combined cycle, composition of mixture Freon, and natural gas vaporizing pressure are evaluated by simulation. The results of these studies show that in the total system, about 400 kWh can be generated by vaporizing 1 ton of LNG, including about 60 kWh/LNG ton recovered from the LNG cold energy when supplying NG in 3.6 MPa.. About 8.2MWh can be produced by using 1 ton of LNG as fuel, compared with about 7 MWh by the conventional combined system. A net efficiency of over 53%HHV could be achieved by the proposed system. In the case of the LNG terminal receiving 5 million tons of LNG per year, this system can generate 240 MW and reduce the power of the sea water pump by more than 2MW. 1998 Elsevier Science Ltd. All rights reserved.1. IntroductionIn the fiscal year 1994, the amount of LNG imported to Japan reached about 43 million tons; of this 31 million tons were used as fuel for power generation. As shown in Fig. 1, about 20% of the LNG imported was used for power generation [2]. Fig. 2 shows the major LNG power generation systems now in operation and their outputs. Several commercial LNG power generation plants have been constructed since 1979, and their total output has reached approximately 73 MW. Among the new power-generation plants without CO2 emission, this value of 73 MW is second to the 450 MW input of geo-thermal power generation plants in Japan, with the exception of power generation by refuse incinerators, and is much larger compared with the 35 MW output of solar-power plants and the 14 MW output of wind-power stations.Table 1 shows the LNG power generation plants constructed in Japan. The economics of LNG power generation became worse as the appreciation of the yen madethe cost of energy kept constant but while raising the construction cost; the adoption of the combined cycle utilizing gas-turbine and steam turbine (hereafter called combined cycle) increased the gas send-out pressure and lowered the power output per ton of LNG. Therefore, no LNG powergeneration plants were constructed in the 1990s due to lower cost effectiveness of the systems.As for the thermal power plant using natural gas as fuel, the steam turbine produced only about 6 MWh of power output per ton of LNG. But recently, improvement in blade-cooling technology and materials of the gas turbine enabled a 1400℃class turbine to be designed and increased the combustion pressure up to 3 MPa. Therefore, as shown in Fig. 3, the heat efficiency of the combined cycle has been improved and the electrical output from 1 ton of LNG has reached about 7MWh.In this paper, a proposal is made for the high-efficiency LNG power generation system based on a new concept which fully utilizes the cold energy without discarding it into the sea. The system is composed of the combined cycle and the LNG power-generation plant.2. High-efficiency LNG power-generation system2.1. Basic componentsFig.4 shows the process flow diagram of the high-efficiency LNG power-generation system. This complex system consists of the combined cycle and the LNG power generation cycle. The combined cycle is composed of a gas turbine (GAS-T) and a steam turbine (ST-T) using natural gas (NG) as fuel, while the LNG power generation cycle is composed of a Freon (uorocarbon) mixture turbine (FR-T) and a natural-gas turbine (NG-HT, NG-LT) using the latent heat of condensation from the exhaust steam and the sensible heat of the exhaust gas as heat sources. The plate fin type heat exchanger can be used for the LNG/natural gas (LNG-CON) and LNG/ Freon mixture (FR-CON). The shell-and-tube type can be selected as exchangers for exhaust steam/natural gas (LNG-VAP),exhaust steam/Freon mixture(FR-VAP), and exhaust gas/natural gas (NG-SH) applications according to the operating conditions.Ice thickness on the surface of the heat-exchanger tubes becomes a problem as heat is exchanged between exhaust gas and cold natural gas or Freon mixture. The ice thickness can be estimated by the technology of heat transfer between LNG and sea water, thus enabling one to avoid blockages due to ice inside the tubes.In addition, stable and continuous send-out of gas is made possible by using a bypass system, even if turbines and pumps for the Freon mixture and natural gas circulating systems (FR-RP, LNG-RP) stop.2.2. Features of the systemThe practical use of the following existing technologies in combination shows the high feasibility of the proposed system:. Power generation using Freon or hydrocarbon type Rankine cycle,. Power generation by natural-gas direct expansion],. TRI-EX type vaporizer which vaporizes LNG by using an intermediate medium or vacuum type LNG vaporizer.The Freon mixture is made up of the HFC type, which is a fluorocarbon consisting of H, F, and C and has no adverse influence on the ozone layer; it enables reduction in exergy loss at the heat exchanger and increases itscirculating flow rate to be achieved.The effective recovery of cold exergy and pressure exergy is made possible by the combined system using natural gas and Freon mixture Rankine cycle.Fig. 5 shows the temperature-heat duty relation when vaporizing 1 kg of LNG in the system shown in Fig. 4. Separation of the condensed natural-gas in two sections enables an increase in the heat duty between Freon (FR) and LNG, and a reduction of difference in temperature of LNG and natural gas between the inlet and outlet of the heat exchanger.3. Evaluation of the characteristics of the proposed system3.1. Process simulationThe characteristics of this system were evaluated by using process simulator. The followings are the conditions used for the calculation:Effciencies of rotating machines LNG compositionGas turbine (GAS-T) 88% CH4 89.39%Steam turbine (ST-T) 85% C2H6 8.65%Natural-gas turbine (NG-HT, LT) 88% C3H8 1.55%Freon turbine (FR-T) 88% iC4H10 0.20%Air compressor (AIR-C) 85% nC4H10 0.15%LNG pump (LNG-MP, RP) 70% iC5H12 0.01%Freon pump (FR-RP) 70% N2 0.05%Natural gas gross heat-value: 10,510 kcal/Nm3AIR/NG flow ratio of gas turbine: 323.2. Effects of send-out pressure of the natural gasWhen natural-gas is sent out at 3.5 or 1.8 MPa, evaluations were made of the effects of send-out pressure of the LNG and change in superheating temperature of the natural gas on the total output of the high pressure (NG-HT) and the low pressure (NG-LT) natural-gas expansion-turbines. Fig. 6 shows the results of this calculation, where self consumption of power is calculated from the power, raising the pressure of the LNG up to the inlet pressure of the turbine minus the power required for the original send-out pressure. In both cases, the inlet pressure rise for the turbine causes an increase of self consumption power, but brings about a greater out-put. About 7 MPa of the inlet pressure of the turbine is appropriate considering the pressure tolerance of the heat exchangers.When the superheating temperature of the natural gas at the inlet to the turbine becomes high, the recovery of power increases, but the temperature of the exhaust gas from the outlet of the natural-gas super heater (NG-SH) declines, thus indicating that there is a limitation to superheating gas.3.3. Effects of combustion pressure of the gas turbineThe outputs of the gas turbine and the steam turbine, and the efficiency per gross heating value were evaluated by changing the combustion pressure of the gas turbine operating at 1300℃turbine-inlet temperature - see Fig. 7.If the combustion pressure of the gas turbine becomes high, the output of the gas turbine increases, but the output of the steam turbine decreases because the rise in combustion pressure causes a lowering of the exhaust-gas temperature at the outlet of the gas turbine and consequently a decline in the steam temperature at the inlet of the steam turbine. However, the overall efficiency of the turbines increases upon increasing the combustion pressure because the increment of gas-turbine output exceeds the decrement of steam turbine output. As a result, taking the pressure loss into account, it is appropriate to set the send-out pressure of the natural gas at the LNG terminal at 3.5 MPa.（FR-vap），3.4. Effects of Inlet pressure of the steam turbineFig. 8 shows the relations between the steam-turbines output and exhaust gas temperatures by changing the steam pressure in the range of 3-7 MPa. As the steam pressure increases, the output of the steam turbine rises and the temperature of the exhaust gases also increase. Besides, the power required for the water-supply pump increases with a rise in the steam pressure. Therefore, the current combined cycles operate at steam pressure of 7 MPa or more because the increment of the output of steam turbine exceeds the additional power required for the water-supply pump.3.5. Rankine cycle using a Freon-mixture refrigerant.The Freon refrigerant was selected from the HFC refrigerants on the basis of marketability, boiling point and freezing-point. Table 2 shows the physical properties of HFC Freon.When only HFC-23 is used as the medium, because of its low freezing-point it never freezes even if heat is exchanged between the LNG and HFC-23. But if HFC-23 is heated by the exhaust steam of the steam turbine, the pressure rises approximately up to the critical pressure. Therefore, the use of HFC-23 is not cost effective, because it is then necessary to set a high design pressure. To cope with this problem, we evaluated the compound refrigerant composed of HFC-134a (with high boiling point) and HFC-23.Fig. 9 shows saturated vapor pressure at various temperatures, the boiling point and the dew point at atmospheric pressure for mixtures of HFC-23 andHFC-134a of various compositions. The saturated pressure at each temperature rises with the increasing mole ratio of HFC-23: Hence, 40-45% of the mole ratio of HFC-23 is the optimal value considering the design pressure of the equipment.Fig. 10 shows the plots of the output of the Freon turbine versus the condensing temperature of the steam turbine when changing the composition of the HFC-23. In this figure, the turbine outlet pressure is determined in such a way that thedifference in temperature between the LNG and Freon mixture is not less than 5℃in the Freon condenser (FR-CON). The Freon turbine's inlet-pressure is set to the saturatedtemperature of the Freon mixture, i.e. less than 2℃from the steam-condensing temperature.This figure indicates that the output of the turbine scarcely correlates with the mole ratio of HFC-23. The higher the steam-condensing temperature becomes, the greater the output per ton of LNG the turbine produces, but in such a case, it is necessary to evaluate the system as a whole because more fuel is required, as described below. The result indicates that the optimal mole composition of HFC-23 and HFC-134a is 40%/60% considering both design pressure and the output of the turbine.3.6. Comprehensive evaluation from the viewpoint of the steam-condensing Temperature.As the dew point of the exhaust gas is 42℃, it is wise to set the exit temperature of the exhaust gas from the natural-gas super heater (NG-SH) to 80℃or more in order to prevent white smoke from the smoke stack. Table 3 shows the effect of the steam-condensing temperature on the generated output of the total system. The lower steam-condensing temperature brings about a higher efficiency of the total system, but also causes a lowering in the inlet temperature of natural-gas turbine. Therefore, it is appropriate to set the steam-condensing temperature at approximately 30℃.When the condensing temperature is 30C, the generated outputs per ton of LNG of the combined cycle and LNG power generation plant are 342.83 and67.55 kWh, respectively, resulting in 402.64 kWh of total generated output aftersubtracting the self-use power. As 48.94 kg of fuel is used for operating the system, the generated outputs of the combined cycle and the total system reach about 7 and 8.2 MWh, per ton of fuel respectively.3.7. Evaluation of exergyNatural-gas is liquefied at an LNG liquefaction terminal, with the consumption of about 380 kWh/LNG-ton: 1 ton of LNG having about 250 kWh of physical exergy as cold exergy and 13.5 MWh of chemical exergy. Fig. 11 shows the result of evaluating the exergy of the system shown in Fig. 4 under the optimal condition. The total output of Freon and natural gas turbines is 67.5 kWh, and the effective recovery percentage of cold exergy is 56%. As 90 kWh out of the pressure exergy can be recovered as output, about 157 kWh of net recovery can be obtained, which indicates the recovery percentage reaches about 63% for 250 kWh of LNG cold exergy. This conversion efficiency is higher than that achieved from chemical exergy to electric power.Most of the exergy loss occurs in the heat exchanger and the turbine, and in mixing with re-condensed LNG. As for the turbines, the loss of energy may be improved by using high-efficiency turbines. On the other hand, modification of the heat exchanger to reduce the energy loss may cause increased complexity of the system and is difficult to be done from the economic viewpoint. Though the recovery.percentage of cold energy in this system is low compared with the 80% in air-separation equipment, this system has the advantage of recovering a large amount of the available cold energy.4. ConclusionThe paper has proposed a high-efficiency LNG power generation system in combination with a combined-cycle power generation system fueled by natural-gas. The system utilizes LNG cold energy and it requires no sea water as a heat source.This system can be applied to LNG vaporization and send-out processes of gas companies or electric-power companies. The system recovers LNG coldenergy as an electric-power output without wasting it into sea water. The system consists of Rankine cycle with Freon mixture and a natural-gas Rankine cycle using the latent heat of exhaust steam from the steam turbine and the sensible heat of exhaust gas from the waste-heat recovery boiler. To improve the total efficiency of the system, a simulation was conducted to evaluate several factors, such as the composition of the Freon mixture, natural gas send-out pressure, as well as the combustion pressure steam inlet pressure, and steam-condensing temperature of the combined cycle. As a result, not less than 60 kWh/LNG-ton of output was generated even at a high natural-gas send-out pressure of 3.5 MPa. This value is considerably higher than the output generated at a LNG send-out pressure of 3 or 4 MPa, as given in Table 2.The system can produce about 400 kWh of net output when vaporizing 1 ton of LNG. While the conventional combined-cycle system in operation generates about 7 MWh when 1 ton of LNG is used as fuel, the system using the same amount of fuel generates about 8.2 MWh with a high degree of efficiency: a not-less-than 53% conversion efficiency was achieved per gross heat value.In the case of an LNG terminal receiving 5 million tons of LNG per year, this system can generate a power of about 240 MW when 600 t of LNG is used in an hour. With the elimination of about 24,000 tons per hour of sea water, which has been used for vaporizing 600 t/h of LNG in the conventional system, no less than 2 MW of electric power for operating sea water pumps can be saved.The proposed system emits no CO2, and can generate a large amount of electricity with high cost efficiency when incorporated into a combined cycle, with no use of sea water. Therefore, we consider that installation of this system is the one of the most favorable means of investment to put a new energy source or energy-saving equipment to practical use.To realize the full potential of this system, it is necessary to understand the heat characteristics of the Freon mixture, the icing and heat transfer characteristics of exhaust steam, the controllability of total system and the characteristics against partial load.References[1] The Center for Promotion of Natural gas Foundation. Research and development report of cold energy utilizing system, 1994[2] Japan's Energy and Economy Research Center. Energy and economy statistical data in 1995[3] Abe. Operating results and future prospect of a recent combined-cycle power generation plant. Thermal and Nuclear Power 1995;46(6):33-41[4] Maertens J. Design of Rankine cycles for power generation. Int. Refrig. 1986;9:137-43[5] Terada, Nakamoto. Power generation utilizing LNG cold. Thermal and Nuclear Power Generation 1986;37(10):66-71[6] Ooka, Ueda, Akasaka. Advanced LNG vaporizer and power generation utilizing LNG cold. Chemical Engineering 1981;45(3):187-90[7] Miura. The development of LNG vaporizer using vacuum steam heat (VSV). Journal of Japan Gas Society 1992;45:34-6[8] Nagai. Software-package and the usage. Chemical Equipment1994;August:31-7[9] Daikin Co. Ltd. Freon Data Sheet of HFC23一个高效的利用液化天然气联合循环余热的发电系统日本大阪541燃气有限公司工程部1-2平野町4肖梅中央谷，1998年9月概述本文提出了一个高效液化天然气气化发电系统，它是利用液化天然气冷能的最佳潜能极限。

毕业设计（论文）外文资料翻译附件1 ：外文资料翻译译文双闭环直流调速系统的说明一、系统分析与综合1. 系统分析（1）在转速、电流双闭环调速系统中，若要改变电动机的转速，应调节什么参数？改变转速调节器的放大倍数Kn行不行？改变电力电子变换器的放大系数Ks 行不行？改变转速反馈系数行不行？若要改变电动机的堵转电流，应调节系统中的什么参数？答：若要改变电动机的转速，改变转速调节器的放大倍数Kn 和电力电子变换器的放大系数Ks 都不行，稳定时n=Un=Un*,所以只有改变给定值Un*和反馈系数才行。

若要改变电动机的堵转电流，同样只须改变给定值Uim*和反馈系数，因为，稳定时，Uim* = Idm, 从式中可得出。

（2）转速、电流双闭环调速系统稳态运行时，两个调节器的输入偏差电压和输出电压各是多少？答：转速、电流双闭环调速系统稳态运行时，两个调节器的输入偏差电压均是零，由式子n=Un=Un*，n=n0 ; Uim* = Idm, Idm=Idl 。

（3）在转速、电流双闭环调速系统中，两个调节器均采用PI 调节器。

当系统带额定负载运行时，转速反馈线突然断线，系统重新进入稳态后，电流调节器的输入偏差电压Ui 是否为零？为什么？答：当系统带额定负载运行时，转速反馈线突然断线，则Un=0，Un =Un*-Un=Un*, 使Ui 迅速达到Uim ，Ui 0 ，速度n 上升，当系统重新进入稳态后，即Id=Idl ，那么，Ui = Uim*- Idl 0，Ui 也不再变化，转速n也不再变化，但，此时的转速n 比反馈线断线时的转速要大。

（4）为什么用积分控制的调速系统是无静差的？答：在积分调节器的调速系统中，能实现无静差，是由于积分调节器控制特点，即积分的记忆和积累作用。

（5）双环调速系统（PI），负载变化，Idl>Idm, 问双环调速系统ACR和ASR 怎么调节，结果如何？答：当负载变化时，Idl>Idm, 转速迅速下降，电流Id 很快增加到Idm，而达限幅值，速度ASR迅速饱和，ACR一直在限流状态下，形成堵转现象，长时间运行会损坏系统。

本科生毕业设计（论文）专业外文翻译原文：Magnesium alloy electric wheel hubmicro-arc oxidation production research译文：镁合金电动车轮毂微弧氧化生产研究指导教师：张清郁职称：讲师学生姓名：陈孟丽学号：1002130301专业：机械设计制造及其自动化院（系）：机电工程学院2015年4月10日Magnesium alloy electric wheel hub micro-arc oxidation production researchMost electric vehicles at home and abr o ad is configured t o aluminum alloy wheel hub,its quality,energy saving,shock absorption,noise reduction and vehicle dynamics characteristics index is much lower than magnesium alloys.Magnesium alloy is30% lighter than aluminum alloy,th e damping effect is30times that of aluminum alloy. Replace the aluminum alloy with magnesium alloy wheel hub,driving the development of magnesium alloy material development and deep processing technology,t o reduce electric vehicle weight and power consumption,energy conservation and environmental protection; T o reduce vibration and noise;Improve ride comfort and electric vehicle dynamic characteristics such as objective(transportation quality each reduce10%,energy consumption will be r educed8%~10%).But its corrosion resistance is poor,seriously limits the monly used chemical oxidation and anode oxidation formation of oxide film on magnesium alloy has certain protective effect,but its corrosion resistance, environmental friendliness,appearance is not satisfactory,be badly in need of the development of new surface treatment.In recent years,people trying to develop a variety of new technologies,such as micro arc oxidation technology,the betterOne Micro-arc oxidation mechanismMicro-arc oxidation technology is a new surface tr eatment technology of gr een environmental protection,can grow in light metal surface in situ ceramic layer directly.Its technological characteristics,surface treatment,as well as the performance of the since the technology was invented by the favour of people,its mechanism is t o light metals such as aluminum,magnesium,titanium and its alloy pu t in electrolyte a q ueous solution as anode, using the method of electrochemical spark discharge spots on the surface of the material, the thermal chemistry,plasma chemistry and electrochemistry,under the joint action of metal oxide ceramic layers of a surface modification technologyTwo research methods and technologyThis topic in the research on magnesium alloy electric wheel hub,higher requirements on the t oughness of the alloy,so choose AM60B,melt and initial temperatur e of468℃,the melting end temperatur e is596℃,the liquidus temperatur e range of 165℃.The chemical composition as shown in table1.T able1AM60B alloy chemical composition(WB/%)Al Zn Mn Si Cu Ni Fe杂质余量5.6～6.4≤0.200.26～0.5≤0.05≤0.008≤0.001≤0.0040.02Mg Because of the magnesium alloy electric wheel hub surface area is larger,generalabove0.4m2,require micro-arc oxidation power supply is bigger,this subject a do pts the lanzhou university of technology institute of materials and development of MAO-300 type nc micro-arc oxidation production device(figure1)micro-arc oxidation on magnesium alloy wheel casting processing,its similar to ordinary anodic oxidation equipment,including special high-voltage power supply,micro-arc oxidation alkaline solution of electrolytic tank,mixing system,cooling system,workpiece with stainless steel plate for peer electrode.With micro-arc oxidation method in sodium silicate and sodium hydroxide electrolyte fluid system in the preparation of magnesium alloy wheel casting oxide ceramic membrane, the concrete technological process first set oxidation process parameters and the alkaline tank sodium silicate solution,the cleaning after micro-arc oxidation of magnesium alloy wheel casting into cell15~20min,clean with clear water tank2~4min,add ho t water in ho t water(80℃,10~15min),closed,then cool in the cold water tank2min,hoisted ou t drainage,drying,examine the hub.After micro-arc oxidation tr eatment must be closed by ho t water,formed by micro-arc oxidation discharge holes so the distribution of the channel and the surrounding a large number of micro cracks will be closed,prevent oxygen t o cause oxidation.After completion of micro-arc oxidation,from after micro-arc oxidation on magnesium alloy wheel casting intercept film sample were analyzed,and to facilitate test analysis,r equest samples made of circular plate,so the sample interception location choice among wheels,mo s t is shown in ing scanning electron microscope analysis of oxide filmFigure1MAO-300type nc micro-arc oxidation power supplyFigure2after micro-arc oxidation magnesium alloy wheel hub casting andinterception of membrane layer analysis sampleThree micro-arc oxidation process parameters on the quality of the film Based on the research of the sample and analysis of micro-arc oxidation technology is, in fact,the substrate magnesium magnesium oxide.Figure3for the dimension of samples before and after oxidation appearance schematic simulation,which is suitable for ceramic oxide film a outward growth,namely the increase of size part,b is the depth of the internal oxidation t o the matrix,a and b interface for initial sample surface position,h for the total thickness of oxide film.Figure3samples dimension changes before and after micro-arc oxidation diagram Larger influence on test has a positive voltage,frequency,duty cycle,current density and oxidation time on the process parameters.Due to the electric casting of magnesium alloy surface area is larger,micro-arc oxidation micro-arc discharge must be formed in the surface can occur after a certain thickness of oxide film,so the formation of the oxide film is needed for the voltage doesn't need much,the current is larger,the oxide film formation and the process of thickening,o ften accompanied by current and voltage mutation.When the oxide film thickness reaches a certain degree,the need t o increase the voltage on both ends of the workpiece,usually at ar ound150V in the micro arc discharge betw een the workpiece and the electrolyte.Increased with the increase of voltage,current,micro-arc density is mo r e and mo r e close,mo r e and mor e bright,and micro-arc constantly beating, basically,the current and voltage,linear increase abo u t180V voltage,the density of micro-arc basically meet the technological requirements,the current growth slowly.When the thickness of oxide film reaches a certain electricityFrom electric casting magnesium alloys is n o t hard t o find in the micro-arc oxidation test result analysis,micro-arc oxidation in the process can be divided into two steps, namely the oxide film formation stage and the stage of micro-arc oxidation film discharge, the formation of oxide film phase as the initial stage,the stage of the supply voltage is small,and after the film to pr oduce micro-arc discharge requires high voltage,for magnesium alloy electric casting the large workpiece with micro-arc oxidation processing surface area is larger,the film for a long time,t o a large extent affected the production efficiency.Experimental results also found that the dc power of oxide film faster than pulse power,in the absence of micro arc discharge,oxide film layer is not dense,it can be seenfrom appearance,need again with pulse power supply for micro-arc oxidation discharge, the oxide film become mo r e dense.In order to improve the production efficiency,to meet the n eed s of industrial production,suggest early low voltage adjustable dc constant voltage power supply are available t o set up the initial oxidation film,forming a complete insulation film in place to ensure that the first phase,and the oxide film in the late discharge can use digital pulse type adjustable power supply,it can shorten the artifacts of micro-arc oxidation time.The size of the current density in a certain extent reflects the intensity of micro-arc oxidation,strongly affect the resulting performance of the micro arc oxidation ceramic layer.The duration of oxidation also seriously affects the coating corrosion resistance: oxidation time is too short,although generat ed mainly the dense layer,bu t the film is too thin,don't have good corrosion resistance;After oxidation time is too long,at some time, with the increase of time,although the overall film thickness increases,bu t the increase is a loose layer,layer density and thinning trend,d o e s n ot favor the coating corrosion resistance,also no t economic.The density of micro arc also related with the pulse frequency,when the pulse frequency increases,the density of micro arc also gradually increased.Will have the electric field set up suddenly,can pr oduce micro arc.In the basic process parameters such as electrolyte concentration,duty ratio and pulse n umbe r of uncertain,the arc voltage is constant commonly,so when the frequency increases,the sustain micro-arc voltage frequency increases,the micro-arc density will increaseFour micro-arc oxide film layer structure characteristicsAfter micro-arc oxidation of magnesium alloy wheel hub interception by Mef3large metallurgical microscope observation of the sample,the micro-arc oxide film surface morphology as shown in figure4.Can be seen from the figure in the wheel hub surface layer is made up of many tiny"small volcanic cone"(figure pr otuberant part ar ound the holes)in dendritic combination,constitute the mesh structure."Small volcanic cone"center has a small hole,this is the electrolyte reaction with matrix micro-arc discharge channel, namely when the micro-arc spew ed molten oxide channel.In addition,because the current micro area local plasma channel is different that differ by the size of the hole,big hole are also distributed ar ound a large n u mbe r of micro cracks,the generation of micro cracks o ften related to the stress that exist in the film.With SSM Analysis Analysis software[6]toanalyze the surface density,including25m film for sample,the hole surface area ratio of 18%,that of micro-arc oxidation film density is better.Figure4magnesium alloy wheel hub micro-arc oxide film layer surface morphologyFigure5AM60B magnesium alloy micro-arc oxidation film section morphology by SEM Figure5is thr ough JMS-6700-f field emission scanning electron microscopy(sem) observed the micro-arc oxide film layer section morphology photos.Figure5shows the average film thickness of a bo u t22(including m,the oxide film and substrate with good, decomposition of a distinct,density on the interface is good,no big holes.By figure5can also see,micro-arc oxide film by the outermost layer of loose layer,the inside of the transition layer and layer in betw een density of three parts,the transitional layer is the interface film layer and substrate,holes and other defects existing in the loose layer,d ens e layer is the key t o improve its corrosion resistance.Figure6is obtained by Phlip X'pert X-ray diffractometer AM60B magnesium alloy wheel hub of micro-arc oxidation film XRD spectrum,according t o the intensity of diffraction peak accumulation analysis shows that the matrix of Mg peak relatively obvious, the main phase of micro-arc oxidation coating is cubic structure of MgO style,surface with Mg2Si2O4and MgAl2O4spinel phase,according t o the test conditions that may also contain SiO2,MgF2and small a mounts of Mg(OH)2,and the oxide of Al,K and Na. Studies have shown that MgAl2O4and Mg2Si2O4can improve the wear resistance of ceramic layer and MgO style the corrosion resistance of ceramic layer play a very important role.This is the micro-arc oxide film performance is higher than the r oot cause of the anode oxidation membrane performance.In addition,micro-arc oxidation ceramic layers of low porosity,and to improve the corrosion resistance of the coatings;Ceramic layer from the substrate on the growth,combined with matrix closely,therefore,is no t easy t o fall off.In addition,the technology can generat e uniform film both inside and outside the material surface layer,expand the scope of application of micro-arc oxidation.Figure6AM60B magnesium alloy micro-arc oxidation film XRD spectrum Five T o detect the corrosion resistance of the micro-arc oxide film layer In order t o meet the requirements of the use of electric cars,micro-arc oxidation on magnesium alloy electric wheel hub on the corrosion resistance test,salt spray testing machine mainly USES the WJ-90after micro-arc oxidation tr eatment of the surface of the wheel hub for salt spray test.After testing found that did not use h ot water seal processing of the surface of the wheel hub48h corrosion rate was0.108%,while only0.073%,afterho t water hole sealing hubs such as chromium than other chemical surface tr eatment processing of low corrosion rate(0.6%).[9],that magnesium alloy after micro-arc oxidation electric wheel hub surface corrosion resistance is superior.T o evaluate a r ough check the appearance of the film,feel is very good,membrane layer uniform light show that membrane surface appearance level is higher.Practice shows that without the micro-arc oxidation of the surface of the magnesium alloy wheel casting coating,its poor corrosion resistance,abrasion resistance,in a very short period of time,began to appear on the surface of parts oxidation falls off ph eno menon,it is difficult t o sell in the market; After micro-arc oxidation treatment,its corrosion resistance,wear-resisting performance is significantSix The conclusion(1)quality of micro-arc oxidation on magnesium alloy electric wheel hub surface influence factor has a positive voltage,frequency,duty cycle,current density and oxidation time on the process parameters.Optimum process parameters for150~180V voltage, current density of1.1A/dm2,oxidation time t o20min,400Hz frequency,duty cycle of 20%.(2)the oxide film is divided into two layers of loose layer and den se layer structure, the dense layer is the main body,the film formed by cubic structure of MgO style,the surface is MgO style and MgA12O4,spinel phase mixture,and combined with matrix and closely for hard ceramic layer and played a key role of the magnesium alloy surface anticorrosion(3)the micro-arc oxidation technology for new surface tr eatment technology of environmental protection,bu t its large area needed for the magnesium alloy casting film for a long time,the production efficiency is low,the mass production t o meet the large area of magnesium alloy castings,micro-arc oxidation power supply can be established by using dc power first initial oxidation film layer,then use pulse power arc discharge strengthening oxide film layer,the ways which are already so den se and har d ceramic oxide film layer can be obtained,also can greatly improve production efficiency.镁合金电动车轮毂微弧氧化生产研究国内外大多数电动车车辆配置为铝合金轮毂，其在质量、节能、减震、降噪和车辆动力学特性等指标大大低于镁合金。

土耳其的能源需求M． Mucuk anｄＤ。

Uｙｓaｌ经济学,经济和行政学院，塞尔丘克大学法律系,42０75，科尼亚,土耳其摘要：本研究的目的是预测在土耳其使用Boｘ－Jeｎｋinｓ方法论20０7 —２０１5年期间的一次能源需求.由能源和自然资源部规定的期限１970至2０06年的年度数据进行的研究中使用。

考虑到单位根检验的结果,能源需求的系列是一阶差分平稳。

位居其后的替代模型可以发现,最合适的模型是能源需求的系列AＲIMＡ(3，1，３）。

根据这个模型，估计结果表明，能源需求也将继续增加的趋势,在预测期内。

据预计,在一次能源需求将在2015年达到11９。

472 T ＯE与相比，应设计用于在土耳其的需求不断增加2０06.因此能源政策增加约22％。

介绍经济政策的最终目标是维持社会福利水平的增加。

有必要通过有效地利用资源，以实现在社会福利的增加，以增加产量.出于这个原因,可以看出，已内化到新的增长模式的技术因素是一个快速发展。

在技术的发展也有助于在对能源的需求的增加。

事实上，在与工业革命发生在18世纪末和19世纪初，生产过程中采用新技术，以及无论在国家的基础,并在全球范围内增加能源消耗带来的。

然而,随着工业化在一起因素，例如人口和城市化也起到了作用，显著作为能源消费的增加解释变量.能量需求，这取决于上面提到的因素，表现出动态结构的未来值,是非常重要的在于要今天实施的政策方面，由于所使用在我们的日常生活中的大部分能量资源具有一个不平衡各地区和储量分布中一直在稳步下降。

上面提到的局限性迫使国家在考虑到可持续增长做出预测已经塑造他们的能源政策。

本研究的目的是预测在土耳其通过Box-Jeｎkins方法的基础上规定的期限1970年至２006年的年度数据对能源的需求期间二零零七年至2015年。

土耳其是不被认为是丰富的化石燃料,诸如石油，天然气和煤炭的国家之列。

出于这个原因，正确的能量需求预测携带在设计在国内实施的策略一个显著值。

内蒙古科技大学本科生毕业设计外文翻译题目：汽车电池工业的挑战：在汽车电力系统中电池已经成为一个越来越集成组件学生姓名：丁文俊学号：1066129102专业：车辆工程班级：车辆10-2班The challenge to the automotive battery industry: the battery has to become an increasingly integrated component within the vehicle electric power systemEberhard Meissner, Gerolf RichterVarta Automotive, Vehicle Electric Systems and System Development, P.O. Box 210520, 30405 Hannover, GermanyAbstractDuring the time that the automotive battery was considered to be just a passive component in a vehicle electric power system, the battery industry’s answer to all new challenges was constructive improvements. The emerging requirements of even higher function reliability cannot, however be met this way. A battery manufacturer of today has to give recommendations for the appropriate choice of the electrical architecture and has to design batteries that suit best the requirements. In addition, manufactures have to be engaged in the technology of battery management, of battery monitoring and state detection, and performance of prediction under future operation conditions. During service on-board a vehicle, battery performance undergoes significant changes, e.g., loss of storage capability, increase in internal resistance, and changes in voltage characteristics. These aging processes have to be considered when the electrical architecture is being designed and management strategies are being formulated. Battery monitoring and state detection must be able to identify and quantify battery degradation. Moreover, performance prediction as well as management strategies have to be corrected on account of the changing battery characteristics.Keywords: Automotive battery; Vehicle electric power system; State-of-charge; State of health; Monitoring; Capacity loss1.IntroductionIn everyday language, the term …automotive battery‟means a battery on board of a road vehicle. The storage device of energy in the vehicle with an internal-combustion engine (ICE) is the SLI battery, which takes its name from the basic electricalfunctions of starting (S), lighting (L) and ignition (I). It provides the electric power for cranking the ICE, buffers electrical energy within the vehicle electric power system during operation, provides electrical energy when the engine is off (especially for lighting), and is recharged from an alternator driven by the ICE. The operating mode of automotive batteries is characterised by …floating‟ in a medium state-of-charge with shallow cycling, where full recharge and full discharge are never achieved [1,2]. At present, SLI batteries are of the lead–acid type, usually with 12V nominal voltage and of flooded design. Despite being installed in series-production vehicles back in the late 1980s, valve-regulated lead–acid (VRLA) batteries have not become widespread in large numbers and are still limited to markets with special requirements such as luxury cars, taxis, agriculture vehicles, motorcycles, and military applications[3]. Different from the …automotive battery‟, vehicle propulsion is the main task of a …traction battery‟. Typical applications are forklift trucks, automatically guided vehicles (AGVS) and electric road vehicles (EVS). From an operation point of view, a traction battery essentially differs from an automotive type in that it is recharged at a recharge station,or is exchanged by another recharged battery. For example,the electric energy for vehicle propulsion is not generated on board of the vehicle, but comes from a (immobile) recharge station. In most cases, the operating mode is characterized by deep cycles, starting from a full state-of-charge, and complete recharge (at least from time to time) afterwards.2. Functions and situation of automotive batteryToday’s vehicle electric power systems with the battery as an essential component are characterized by the increasing number and associated power demand of electrical consumers, by packaging issues, and by the limitation of the operational voltage of electronic components.With the old d.c. generators, the SLI battery had to act as a charge buffer element when the ICE was idling due to their low power output at low revolutions. After introduction of ac alternators of increasing power and efficiency, this was not an issue for many years. Nowadays, however, electronic ICE controllers allow reduced idlingrpm to lower emissions, while many comfort components and mechanical devices that are driven electrically require electrical power. Under poor weather conditions in a hot climate, with airconditioning, headlights and wipers on and the electrical cooling fan of the ICE in operation periodically, the alternator cannot supply sufficient current for a modern highly equipped A-size car. While the alternator provides about 70 A, the overall current load fluctuates between 80 and 100 A, and the battery has to provide the difference.When (electrical power assisted) steering is activated, battery discharge peaks reach −60 A. More current (up to 120 A) is generated when idling is over and the ICE rpm increase. But with increasing alternator voltage, the load current increases as well as many loads have a ohmic-like behaviour. For battery recharge, there is not more than +40A left in best case and +20A on average. In this case of load-levelling, charge balance under stop-and-go conditions will be negative, whichmay compromise cranking capability at the long term. Negative charge balance, compromising cranking capability, may have other reasons as well, e.g., extended use of comfort components when the engine is off. In all these cases, an intelligent energy management, which uses information from battery state detection, may switch off non-essential consumers, provide appropriate control to the alternator, or even the idle speed and the automatic gearbox, [2]3. New functions of automotive batteryNew vehicle electric designs are driven by fuel economy and reduced emissions, as well as by new functions for improvement of safety and comfort, reliability, and the availability of the vehicle, i.e., cranking and energy supply to essential functions under all (standard or misuse) conditions. While some of these functions are already established, such as electrically controlled and powered systems for braking, steering and stabilization, others are just being introduced. The stop–start operation mode of the ICE will require even more battery cycling when the electrical system has to be bridged while the ICE is at standstill. The same is true for the torque assist/acceleration assist (boost) mode. Planned generation of electrical energy (onlywhen it is economically meaningful), including electrical brake energy recovery (recuperation), requires knowledge about the capability of the battery to accept charge.4. Battery state detection—foundation of vehicle electrical power managementThe necessary steps to analyze battery status, and to make use of this information, are discussed here in more detail, as the terms used in the field of battery monitoring and energy management are often used in different manner. Especially, there is no unequivocal meaning for the term ‘battery management system’(BMS). In most cases, any feedback to the battery is missing, i.e., the battery is only (passively) monitored and information is generated, rather than it is (actively) Managed. Any analysis of an arbitrary system requires information,i.e., input data. In case of the battery, voltage U, temperature T and current i can be measured directly (observable values). Measurements of a sub-set of such data are ‘battery monitoring’,as battery operation is only (passively) observed These data are input information that are being processed during ‘battery state detection’(BSD). This term comprises analysis of the state vector P of the battery, i.e., values of internal parameters or properties that may not be accessible for direct measurement (non-observable values), but that determine battery state, property, performance and capability.Examples for such internal battery parameters are acid gravity, active material utilization, and any inhomogeneity of these.4.1 Determination of loss of capacit yFollowing the introduction of antimony-free grid alloys, grid corrosion has become a common failure mode that limits battery use in hot environments. In moderate environments,the ohmic part of a value is only then a helpful indication for battery degradation if electrolyte resistance is a relevant failure mode, e.g., with AGM batteries that suffer of dry-out. On the other hand, reduced grid corrosion together with increased cycling duty have resulted in loss of capacity (i.e., charge storage capability measured at the standard low rate) due to active-material degradation beingvery often a prominent failure mode. In many cases, the limiting process of active-material degradation from cycling is softening of the positive active material. This soft material is still in place but is so poorly connected to the grid that discharge is significantly impeded at technically relevant rates. There is, however, some electrical connection of this soft active material to the grid and this is why it is charged to PbO2. This view is supported by the fact that even shed material has been found to be charged PbO2 rather than discharged PbSO4 [5]. If there is no significant sulfation at the negative electrode, then electrolyte is not involved in this type of storage capability loss, i.e., the electrolyte specific gravity would be the original value for a (hypothetical) full recharge. The amount of liquid that can bestored in the tank (its charge storage capability CSC) is represented by the height times the width of this 2-dimensional representation. Change in the height of the liquid level represents the change in actual pressure (i.e., the equilibrium voltage U OO), and the width the amount of liquid (i.e., charge throughput Q) that is drawn from the tank when the height is changed by a certain amount. and is an approximation of the lead–acid battery characteristic . From the considerations given above, the capacity loss due to active-material degradation does not use up electrolyte, i.e., the electrolyte relative density in the fully charged state is the same as that for a fresh battery. If the battery is discharged at a low rate, negligible changes are observed until the available portion of the active material is consumed. This situation is illustrated with a set of ‘stones’on the bottom of the storage tank. The storage capability above these ‘stones’is unchanged, and the existence of the ‘stones’is scarcely obvious before the level of the liquid falls to their level. Then, the pressure in the tank decreases suddenly.4.2 Quantification of acid stratificationAcid stratification is a consequence of the participation of sulfuric acid from the electrolyte in the electrochemical reactions. Convection of the free electrolyte is generated by differences in local concentration, i.e., specific gravity of the electrolyte, and results in electrolyte concentration being higher in the lower part of the cells than in the upper part. Suppression of this electrolyte convection is one of the majorbenefits of electrolyte immobilization in VRLA batteries. To date, acid stratification has received little attention in the case of SLI batteries. Due to the usual rather shallow cycling operation, generation of stratification is limited, and mechanical movement of the battery in the vehicle, as well as some gas evolution during charge at elevated temperature (when the battery is located under the hood), supports equilibration. Cycling operation is more harsh today and generates more stratification, while there is less electrolyte mixing due to the use of battery designs with low-gassing grid and closer plate packaging, and to better vehicle suspension. The reduction in the storage capability of a SLI battery (12 V/110 Ah) when cycled between 80 and 20% SOC at the C20 rate is shown. Already after six cycles, the charged battery (14.7V for 24 h) provides less than 70% of its nominal capacity (Note, when the battery was turned upside down several times and recharged at 16V, stratification was overcome the and capacity was fully recovered). This demonstrates the relevance of acid stratification for battery state detection5. SummaryNowadays, vehicle electric systems are driven by fuel economy, ecology, and by new functions for improvement of safety, comfort, and reliability. Electrically driven components that require electrical power of high reliability are penetrating the mass market, and the emerging start–stop systems will bring new challenges. Overall the requisite electrical performance is increasing with much higher fluctuations of the load demand. This cannot be accommodated simply by scaling up today’s components. All of the above also applies to the battery, especially as packaging of the rather bulky battery within the vehicle is becoming more and more of an issue for designers. Consultation with the battery manufacturer for packaging and possibly partitioning into two batteries may be helpful in many cases. While there is still potential for the further technical improvement of automotive batteries, procedures are needed for optimum use of the battery resource, i.e., knowledge of actual SOC, power capability, and quantification of the degradation of the battery performance as an input for energy management. Early detection of possible restrictions of reliability by battery state detection allows for actions by the energy management system well inadvance. The expertise of the battery manufacturer is challenged by this task.References[1] E. Meissner, G. Richter, J. Power Sources 95 (2001) 13–23.[2] E. Meissner, G. Richter, J. Power Sources 116 (2003) 79–98.[3] J.R. Pierson, R.T. Johnson, J. Power Sources 42 (1993) 237–246.[4] D. Berndt, J. Power Sources 100 (2001) 29–46.[5] D. Berndt, Maintenance-free Batteries, second ed., John Wiley &Sons, New York, 1997.汽车电池工业的挑战：在汽车电力系统中电池已经成为一个越来越集成组件埃伯哈德迈斯纳，高尔夫级瓦尔塔汽车、车辆电气系统和系统开发，邮政信箱210520，30405汉诺威，德国文摘在起初期间，汽车电池被认为只是一个无源元件。

翻译原文 (4)Photovoltaic (PV) Electric Systems (4)The Advantages of Mitsubishi Solar Panels (5)1光伏电力系统光伏电力系统利用太阳能电池吸收太阳光线，并将这种能量转化成电能。

这个系统让广大家庭通过一种清洁，可靠，平静的方式来产生电能，这样就可以补偿将来的部分电能支出，也减少了对输电网的依赖。

太阳能电池一般是由经改进的硅，或者其他能够吸收阳光并将之转化成电能的半导体材料制成。

太阳能电池是相当耐用的（1954年在美国安装的第一个光伏电力系统至今仍在运营）。

绝大多数的生厂商都担保自己的产品的电源输出至少维持20年。

但大多数的有关太阳能研究的专家认为一个光伏电力系统至少能维持25到30年。

1.1 太阳能电池的类型目前有单晶硅，多晶硅和薄膜三种基本形式的光伏组件。

这些类型的电池工作效率都很好但单晶硅电池效率最好。

薄膜技术的电池以成本低为特色，而且伴随着太阳能电池板的发展它的效率也在不断地提高。

越来越多的生厂商以及各种各样的电池型号在当今市场上出现。

一个太阳能技术的支持者可以帮你分析各个系统的利弊，如此你就可以得到为你所用数十年的最佳的系统设计方案。

1.2光伏电力系统如何运作光电板通常安装在建筑物顶部，通过逆变器来引到建筑物中。

逆变器将通过太阳能板产生的直流电转化成交流电，而在当今美国交流电是向建筑提供电动力的主要形式。

朝南方向的太阳能板能使能量的收集效果最大化，大部分都是与建筑物顶部成60度的位置安放太阳能电池。

有关太阳能电池发电的更多的信息，可以查询Cooler Planet’s的《太阳能电池如何工作》。

朝南方向的太阳能板能使能量的收集效果最大化，大部分都是与建筑物顶部成60度的位置安放太阳能电池。

1.3 太阳能电池板与光伏建筑一体化太阳能电池板是用于捕获太阳光的平面板，他们以阵列的形式安装在建筑物顶部或者柱子上。

他们是传统的用于获得太阳能的阵列形式。

景德镇陶瓷学院毕业设计(论文)有关外文翻译院系：机械电子工程学院专业：机械设计制造及其自动化姓名：李东波学号：200610310131指导教师：吕冬青（老师）完成时间：2011年4月20日说明1、将与课题有关的专业外文翻译成中文是毕业设计（论文）中的一个不可缺少的环节。

此环节是培养学生阅读专业外文和检验学生专业外文阅读能力的一个重要环节。

通过此环节进一步提高学生阅读专业外文的能力以及使用外文资料为毕业设计服务，并为今后科研工作打下扎实的基础。

2、要求学生查阅与课题相关的外文文献3篇以上作为课题参考文献，并将其中1篇（不少于3000字）的外文翻译成中文。

中文的排版按后面格式进行填写。

外文内容是否与课题有关由指导教师把关，外文原文附在后面。

3、指导教师应将此外文翻译格式文件电子版拷给所指导的学生，统一按照此排版格式进行填写，完成后打印出来。

4、请将封面、译文与外文原文装订成册。

5、此环节在开题后毕业设计完成前完成。

6、指导教师应从查阅的外文文献与课题紧密相关性、翻译的准确性、是否通顺以及格式是否规范等方面去进行评价。

指导教师评语：签名：年月日计算机辅助夹具设计 - 回顾与未来趋势J.塞西尔虚拟企业工程实验室（VEEL），工业工程处，新墨西哥州立大学，拉斯克鲁塞斯，美国夹具设计是一个重要的工艺设计活动，因为它的自动化对计算机辅助设计和计算机辅助制造（CAM）的一体化是至关重要的。

在本文提供了夹具设计最先进的国家的审查办法。

夹具设计现有目前的缺点方法和研究领域集中在不久的将来的发展也已确定。

关键词：计算机辅助设计，计算机辅助制造;夹具设计1．导言夹具是是用来固定某个工件的位置的机构，利用机械工具来准确的固定工件和在加工过程中支撑着工件。

通常情况下，夹具设计包括压板，定位装置和支撑装置，以及相应的夹具元件来实现各自的职能。

在制造业中，夹具设计的自动化是一个重要的研究领域，必须让设计和制造实现一体化。

夹具的设计是一项复杂的任务，作为一个关键的是设计制造环节，特别是在现代计算机集成制造（CIM）环境[1,2]。

热能与动力工程毕业设计文献翻译文献翻译题目生水源热泵空调系统学生姓名专业班级热能与动力工程08-1 学号院（系）机电工程学院指导教师（职称）完成时间生水源热泵空调系统Yong Cho , Rin YunA K-Water Institute, Korea Water Resources Corporation, 462-1, Jeonmin-dong, Daejeon305-730, Republic of KoreaB Department of Mechanical Eng., Hanbat National Univ., Duckmyung-dong, San 16-1, Daejeon 305-719, Republic of Korea摘要生水源是很有发展前景的新热源之一，研究人员正在将生水源和其他水源(如地面水、湖泊水、河流水和污水)一起作为研究对象。

一般来说,取于环境再供给水质处理设备的水就叫做生水。

在这个课题中，利用供给水质处理设备的生水热能来工作的热泵机组的制冷和制热性能还有待研究。

每两个被测的热泵的热容量为65.2KW，并且通常安置在加热或制冷的控制中心房间。

可以运用焊接的金属板接收来自于生水源的热能。

除了春季，与周围的空气源相比，生水源能够提供良好的热源。

在春秋季节，加热和制冷的负荷极低，因此，生水源热泵系统在这些季节表现不佳。

关键词生水源/热泵/加热和制冷/部分负荷性能1.引言水源有很多种,像地面水,湖泊水,河水,污水和生水。

生水是这些很有发展前景的热源之一。

一般来说,这种水取于环境再通过大型的管道进入水质处理设备来进行后续处理或净化。

像那种没有经过处理的水源就叫做生水。

被调往多个区域供水系统的生水通过各种渠道的运输流动是产生巨大温差的来源。

在这个研究项目中，生水被当作热泵系统的热源来完成水质处理设备整合操作中心的加热和冷却过程。

在实际生活中我们很难找到可以把生水当作热源的相似或相近的操作系统。

混合动力汽车毕业论文中英文资料对照外文翻译文献对插电式混合动力电力车技术成本效益分析安德鲁辛普森国家可再生能源实验室摘要插入式混合电动汽车（PHEVs）已经成为一个很有前途的技术，使用电取代石油消费。

然而，有一个非常广泛的混合动力汽车的设计与大大变成本和效益。

特别是电池成本，燃料成本，车辆性能属性和驾驶习惯大大影响PHEVs相对价值。

本文提出了一种成本（车辆购置成本和能源成本）和收益减少（对比石油消费PHEVs）相对于混合动力电动汽车和传统。

详细仿真模型，用于预测石油和混合动力汽车的成本削减设计相比，基于中型轿车。

两个动力总成技术方案被认为是探索短期和PHEVs长期前景。

分析认为，石油减少超过45％，每台车辆可以达到20英里（32公里），或储存更多的能量配备PHEVs。

然而，这些车辆长期增量成本预计将超过8,000美元，比近期成本高得多。

一个简单的经济分析表明，高石油价格和低成本的电池需要PHEVs做出引人注目的业务案例。

然而，大油气PHEVs为政府加快混合动力汽车技术的部署提供强大的理由。

关键词插入式混合动力；混合动力电动汽车；二次电池的电池；1 介绍插入式混合动力电动汽车插入式混合电动车最近出现了有希望的替代方案，使用电要取代石油消费的车队相当一部分[1]。

插件的混合电动汽车（混合动力汽车）是一种混合动力电动汽车充电的能力，其电化学能源（戊肝）从一板外源产品，如电力公司电网（电力储存）。

车辆可以当时正处在一个电荷消耗（CD）的模式，降低了系统的状态充电（SOC）的，从而使用电力，以取代液体燃料，否则将被消耗。

这是液体燃料典型的石油（汽油或柴油），尽管PHEVs也可以使用，如生物燃料或替代氢气。

PHEV的电池通常在混合电动汽车相比有较大的能力，从而增加潜在的石油流离失所。

1.1插入式混合动力电动汽车术语插入式混合电动汽车的特点是“PHEVx”符号，其中“X”通常是指汽车的全电范围（阿英俄）作为英里的距离定义的并联混合动力汽车可以完全充电驱动器之前需要操作的引擎。

能源与动力工程毕业设计一、课程说明课程编号：100135Z11课程名称：毕业设计/Graduation Project课程类别：专业教育课程（集中实践环节）学时/学分：8周/8学分先修课程：教学计划中所有课程和实践环节适用专业：能源与动力工程教材、教学参考书：专业课相关教材和国家标准、规范二、课程设置的目的意义本课程是大学本科四年级学生的实践教学课程，目的是使学生充分利用所学专业知识，通过查阅专业资料，确定方案，开展相关设计工作。

该课程是学生走向社会独立解决工程问题的一次训练，通过毕业设计使学生初步掌握解决工程实际问题的能力，获得实践经验和本领，从而为继续深造或走向社会奠定坚实的基础。

三、课程的基本要求1．培养学生综合运用所学的基础理论知识和专业知识分析和解决工程技术问题的能力。

2．进一步深化和拓宽学生的知识面，提高学生的自学能力和独立工作的能力。

3．使学生受到科研人员和工程师的双重训练，培养其开展科学研究工作的初步能力，包括：（1）调查研究、文献检索和搜集资料的能力；（2）方案论证，确定实验和设计方案的能力；（3）进行科研实验及理论分析、设计和计算的能力；（4）计算工程技术与经济指标的综合能力；（5）计算机计算和绘图的能力；（6）撰写论文和设计说明书的能力；（7）协同合作及组织工作的能力。

4．培养学生的团队精神、创新精神；树立正确的人生观、价值观，在思想政治素质方面得到进一步提高。

四、教学内容、重点难点及教学设计课程基本内容1、毕业设计双向选题：参照学院毕业设计双向选择实施办法；2、下达毕业设计任务书：说明设计内容及其要求；3、查阅、撰写文献综述；4、毕业实习，收集数据；5、中英文翻译；6、开题：确定研究方法、技术路线及毕业设计的主要内容；7、进行毕业设计：选择实验装置、设备、仪表、测试方法；实验程序设计；实验数据的处理和结果分析；利用技术经济指标对设计结果进行评价。

8、绘制相关设计图纸；9、撰写毕业论文；10、参加毕业答辩。

外文文献翻译
能源与动力学院School of Energy and Power
专业班级：热能与动力工程
学生姓名：曾群
学生学号： 2011101334
指导教师：王培斌
2015年 5 月 10 日
一、目的：
1．了解国外相关知识的发展；
2．熟悉外文科技文献的写作格式及特点；
3．熟悉和巩固所学专业外语的有关知识；
4．学会中英（外）文文献的检索方法。

二、选题要求：
1．学生自主选题，经指导教师审查合格。

2．篇幅在3000汉字以上，较完整的一篇外文论文
3．内容与所学专业相关，并注明来源。

三、译文要求：
1．译文正确，内容完整，图可以复印后贴于适当位置。

2．译文打印在A4纸上，原稿复印后附在译文后。

四、时间安排：
在毕业设计开题3周内完成。

外文文献资料简表。

自动化专业毕业设计（论文）外文翻译Electronic power steering systemWhat it isElectrically powered steering uses an electric motor to drive either the power steering HYPERLINK "/infobank/epc.htm" \t "_top" hydraulic pump or the steering linkage directly. The power steering function is therefore independent of engine speed, resulting in significant energy savings.How it works :Conventional power HYPERLINK "/infobank/epc.htm" \t "_top" steering systems use an engine accessory belt to drive the pump, providing pressurized fluid that operates a piston in the power steering gear or actuator to assist the driver.In electro-hydraulic steering, one electrically powered steering concept uses a high efficiencypump driven by an HYPERLINK "/infobank/epc.htm" \t "_top" electric motor. Pump speed is regulated by an electric controller to vary pump pressure and flow, providing steering efforts tailored for different driving situations. The pump can be run at low speed or shut off to provide energy savings during straight ahead driving (which is most of the time in most world markets).Direct electric steering uses an electric motor attached to the HYPERLINK "/infobank/epc.htm" \t "_top" steering rack via a gear mechanism (no pump or fluid). A variety of motor types and gear drives is possible. A microprocessor controls steering dynamics and driver effort. Inputs include vehicle speed and steering, wheel torque, angular position and turning rate.Working In Detail:A "steering sensor" is located on the input shaft where it enters the gearbox housing. The steering sensor is actually two sensors in one: a "torque sensor" that converts steering torque input and its direction into voltage signals, and a "rotation sensor" that converts the rotation speed and direction into voltage signals. An "interface" circuit that shares the same housing converts the signals from the torque sensor and rotation sensor into signals the control electronics can process. Inputs from the steering sensor are digested by a microprocessor control unit that also monitors input from the vehicle's HYPERLINK "/infobank/epc.htm" \t "_top" speed sensor. The sensor inputs are then compared to determine how much power assist is required according to a preprogrammed "force map" in the control unit's memory. The control unit then sends out the appropriate command to the " HYPERLINK "/infobank/epc.htm" \t "_top" power unit" which then supplies the electric motor with current. The motor pushes the rack to the right or left depending on which way the voltage flows (reversing the current reverses the direction the motor spins). Increasing the current to the motor increases the amount of power assist.The system has three operating modes: a "normal" control mode in which left or right power assist is provided in response to input from the steering torque and rotationsensor's inputs; a "return" control mode which is used to assist steering return after completing a turn; and a "damper" control mode that changes with vehicle speed to improve road feel and dampen kickback.If the steering wheel is turned and held in the full-lock position and steering assist reaches a maximum, the control unit reduces current to the electric motor to prevent an overload situation that might damage the motor. The control unit is also designed to protect the motor against voltage surges from a faulty HYPERLINK "/infobank/epc.htm" \t "_top" alternator or charging problem. The electronic steering control unit is capable of self-diagnosing faults by monitoring the system's inputs and outputs, and the driving current of the electric motor. If a problem occurs, the control unit turns the system off by actuating a fail-safe relay in the power unit. This eliminates all power assist, causing the system to revert back to manual steering. A dash EPS warning light is also illuminated to alert the driver. To diagnose the problem, a technician jumps the terminals on the service check connector and reads out the HYPERLINK "/infobank/epc.htm" \t "_top" trouble codes. INCLUDEPICTURE "/infobank/images/eps-18-4.gif" \* MERGEFORMATINETHYPERLINK "/infobank/images/c01e.gif" click here to see a bigger HYPERLINK "/infobank/images/c01e.gif"INCLUDEPICTURE "/infobank/images/c01e.gif" \*MERGEFORMATINETElectric power steering systems promise weight reduction, fuel savings and package flexibility, at no cost penalty.Europe's high fuel prices and smaller vehicles make a fertile testbed for electric steering, a technology that promises automakers weight savings and fuel economy gains. And in a short time, electric steering will make it to the U.S., too. "It's just just a matter of time," says AlyBadawy, director of research and development for Delphi Saginaw Steering Systems in Saginaw, Mich. "The issue was cost and that's behind us now. By 2002 here in the U.S. the cost of electric power steering will absolutely be a wash over hydraulic." Today, electric and hybrid-powered vehicles (EV), including Toyota's Prius and GM's EV-1, are the perfect domain for electric steering. But by 2010, a TRW Inc. internal study estimates that one out of every three cars produced in the world will be equipped with some form of electrically-assisted steering. The Cleveland-based supplier claims its new steering systems could improve fuel economy by up to 2 mpg, while enhancing handling. There are true bottom-line benefits as well for automakers by reducing overall costs and decreasing assembly time, since there's no need for pumps, hoses and fluids. Another claimed advantage is shortened development time. For instance, a Delphi group developed E-TUNE, a ride-and-handling software package that can be run off a laptop computer. "They can take that computer and plug it in, attach it to the controller and change all the handling parameters -- effort level, returnability, damping -- on the fly," Badawy says. "It used to take months." Delphi has one OEM customer that should start low-volume production in '99. HYPERLINK "/adlog/c/r=12640&s=790604&o=13886:14023:13888:15399:&h=c n&p=&b=14&l=&site=23&pt=&nd=&pid=&cid=&pp=100&e=&rqid=01c17-ad-e8480771F615DF093&orh=LINE&oepartner=&epartner=&ppartner=&pdom=&cpnmod ule=&count=&ra=10.15.56.33&t=2008.04.19.09.09.02/http://cm/ck/9 998-57911-18316-1?mpt=2008.04.19.09.09.02" \t "_blank" Electric steering units are normally placed in one of three positions: column-drive, pinion-drive and rack-drive. Which system will become the norm is still unclear. Short term, OEMs will choose the steering system that is easiest to integrate into an existing platform. Obviously, greater potential comes from designing the system into an all-new platform. "We have all three designs under consideration," says Dr. Herman Strecker, group vice president of steering systems division at ZF in SchwaebischGmuend, Germany. "It's up to the market and OEMs which version finally will be used and manufactured." "The large manufacturers have all grabbed hold of what they consider a core technology," explains James Handy sides, TRW vice president, electrically assisted steering in Sterling Heights, Mich. His company offers a portfolio of electric steering systems (hybrid electric, rack-, pinion-, and column-drive). TRW originally concentrated on what it still believes is the purest engineering solution for electric steering--the rack-drive system. The system is sometimes refer to as direct drive or ball/nut drive. Still, this winter TRW hedged its bet, forming a joint venture with LucasVarity. The British supplier received $50 million in exchange for its electric column-drive steering technology and as sets. Initial production of the column and pinion drive electric steering systems is expected to begin in Birmingham, England, in 2000."What we lack is the credibility in the steering market," says Brendan Conner, managing director, TRW/LucasVarity Electric Steering Ltd. "The combination with TRW provides us with a good opportunity for us to bridge that gap." LucasVarity currently has experimental systems on 11 different vehicle types, mostly European. TRW is currently supplying its EAS systems for Ford and Chrysler EVs in North America and for GM's new Opel Astra.In 1995, according to Delphi, traditional hydraulic power steering systems were on 7596 of all vehicles sold globally. That 37-million vehicle pool consumes about 10 million gallons in hydraulic fluid that could be superfluous, if electric steering really takes off. The present invention relates to an electrically powered drive mechamsm for providing powered assistance to a vehicle steering mechanism. According to one aspect of the present invention, there is provided an electrically powered driven mechanism for providing powered assistance to a vehicle steering mechanism having a manually rotatable member for operating the steering mechanism, the drive mechanism including a torque sensor operable to sense torque being manually applied to the rotatable member, an electrically powered drive motor drivingly connected to the rotatable member and a controller which is arranged to control the speed and direction of rotation of the drive motor in response to signals received from the torque sensor, the torque sensor including a sensor shaft adapted for connection to the rotatable member to form an extension thereof so that torque is transmitted through said sensor shaft when the rotatable member is manually rotated and a strain gauge mounted on the sensor shaft for producing a signal indicative of the amount of torque being transmitted through said shaft. Preferably the sensor shaft is non-rotatably mounted at one axial end in a first coupling member and is non-rotatably mounted at its opposite axial end in a second coupling member, the first and second coupling members being inter-engaged to permit limited rotation there between so that torque under a predetermined limit is transmitted by the sensor shaft onlyand so that torque above said predetermined limit is transmitted through the first and second coupling members. The first and second coupling members are preferably arranged to act as a bridge for drivingly connecting first and second portions of the rotating member to one another. Preferably the sensor shaft is of generally rectangular cross-section throughout the majority of its length. Preferably the strain gauge includes one or more SAW resonators secured to the sensor shaft. Preferably the motor is drivingly connected to the rotatable member via a clutch .Preferably the motor includes a gear box and is concentrically arranged relative to the rotatable member. Various aspects of the present invention will hereafter be described, with reference to the accompanying drawings, in which :Figure 1 is a diagrammatic view of a vehicle steering mechanism including an electrically powered drive mechanism according to the present invention, Figure 2 is a flow diagram illustrating interaction between various components of the drive mechanism shown in Figure 1 ,Figure 3 is an axial section through the drive mechanism shown in Figure 1, Figure 4 is a sectional view taken along lines IV-IV in Figure 3,Figure 5 is a more detailed exploded view of the input drives coupling shown in Figure 3, and Figure 6 is a more detailed exploded view of the clutch showing in Figure 3. Referring initially to Figure 1 , there is shown a vehicle steering mechanism 10 drivingly connected to a pair of steerable road wheels The steering mechanism 10 shown includes a rack and pinion assembly 14 connected to the road wheels 12 via joints 15. The pinion(not shown) of assembly 14 is rotatably driven by a manually rotatable member in the form of a steering column 18 which is manually rotated by a steering wheel 19.The steering column 18 includes an electric powered drive mechanism 30 which includes an electric drive motor (not shown in Figure 1) for driving the pinion in response to torque loadings in the steering column 18 in order to provide power assistance for the operative when rotating the steering wheel 19.As schematically illustrated in Figure 2, the electric powered drive mechanism includes a torque sensor20 which measures the torque applied by the steering column 18 when driving the pinion and supplies a signal to a controller 40. The controller 40 is connected to a drive motor 50 and controls the electric current supplied to the motor 50 to control the amount of torque generated by the motor 50 and the direction of its rotation. The motor 50 is drivingly connected to the steering column 18 preferably via a gear box 60, preferably an epicyclic gear box, and a clutch 70. The clutch 70 is preferably permanently engaged during normal operation and is operative under certain conditions to isolate drive from the motor 50 to enable the pinion to be driven manually through the drive mechanism 30. This is a safety feature to enable the mechanism to function in the event of the motor 50 attempting to drive the steering column too fast and/or in the wrong direction or in the case where themotor and/or gear box have seized.The torque sensor 20 is preferably an assembly including a short sensor shaft on which is mounted a strain gauge capable of accurately measuring strain in the sensor shaft brought about by the application of torque within a predetermined range. Preferably the predetermined range of torque which is measured is 0-lONm; more preferably is about l-5Nm.Preferably the range of measured torque corresponds to about 0-1000 microstrain and the construction of the sensor shaft is chosen such that a torque of 5Nm will result in a twist of less than 2° in the shaft, more preferably less than 1 ° .Preferably the strain gauge is a SAW resonator, a suitable SAW resonator being described inWO91/13832. Preferably a configuration similar to that shown in Figure 3 of WO91/13832 is utilised wherein two SAW resonators are arranged at 45°to the shaft axis and at 90°to one another. Preferably the resonators operate with a resonance frequency of between 200-400 MHz and are arranged to produce a signal to the controller 40 of 1 MHz ± 500 KHz depending upon the direction of rotation of the sensor shaft. Thus, when the sensor shaft is not being twisted due to the absence of torque, it produces a 1 MHz signal. When the sensor shaft is twisted in one direction it produces a signal between 1.0 to 1.5 MHz. When the sensor shaft is twisted in the opposite direction it produces a signal between 1.0 to 0.5 MHz. Thus the same sensor is able to produce a signal indicative of the degree of torque and also the direction of rotation of the sensor shaft. Preferably the amount of torque generated by the motor in response to a measured torque of between 0-10Nm is 0-40Nm and for a measured torque of between l-5Nm is 0-25Nm.Preferably a feed back circuit is provided whereby the electric current being used by the motor is measured and compared by the controller 40 to ensure that the motor is running in the correct direction and providing the desired amount of power assistance. Preferably the controller acts to reduce the measured torque to zero and so controls the motor to increase its torque output to reduce the measured torque. A vehicle speed sensor (not shown) is preferably provided which sends a signal indicative of vehicle speed to the controller. The controller uses this signal to modify the degree of power assistance provided in response to the measured torque. Thus at low vehicle speeds maximum power assistance will be provided and a high vehicle speeds minimum power assistance will be provided。

电力系统电力系统介绍随着电力工业的增长，与用于生成和处理当今大规模电能消费的电力生产、传输、分配系统相关的经济、工程问题也随之增多。

这些系统构成了一个完整的电力系统。

应该着重提到的是生成电能的工业，它与众不同之处在于其产品应按顾客要求即需即用。

生成电的能源以煤、石油，或水库和湖泊中水的形式储存起来，以备将来所有需。

但这并不会降低用户对发电机容量的需求。

显然，对电力系统而言服务的连续性至关重要。

没有哪种服务能完全避免可能出现的失误，而系统的成本明显依赖于其稳定性。

因此，必须在稳定性与成本之间找到平衡点，而最终的选择应是负载大小、特点、可能出现中断的原因、用户要求等的综合体现。

然而，网络可靠性的增加是通过应用一定数量的生成单元和在发电站港湾各分区间以及在国内、国际电网传输线路中使用自动断路器得以实现的。

事实上大型系统包括众多的发电站和由高容量传输线路连接的负载。

这样，在不中断总体服务的前提下可以停止单个发电单元或一套输电线路的运作。

当今生成和传输电力最普遍的系统是三相系统。

相对于其他交流系统而言，它具有简便、节能的优点。

尤其是在特定导体间电压、传输功率、传输距离和线耗的情况下，三相系统所需铜或铝仅为单相系统的75%。

三相系统另一个重要优点是三相电机比单相电机效率更高。

大规模电力生产的能源有：1.从常规燃料（煤、石油或天然气）、城市废料燃烧或核燃料应用中得到的蒸汽；2.水；3.石油中的柴油动力。

其他可能的能源有太阳能、风能、潮汐能等，但没有一种超越了试点发电站阶段。

在大型蒸汽发电站中，蒸汽中的热能通过涡轮轮转换为功。

涡轮必须包括安装在轴承上并封闭于汽缸中的轴或转子。

转子由汽缸四周喷嘴喷射出的蒸汽流带动而平衡地转动。

蒸汽流撞击轴上的叶片。

中央电站采用冷凝涡轮，即蒸汽在离开涡轮后会通过一冷凝器。

冷凝器通过其导管中大量冷水的循环来达到冷凝的效果，从而提高蒸汽的膨胀率、后继效率及涡轮的输出功率。

而涡轮则直接与大型发电机相连。

中英文资料对照外文翻译文献The basics of Steam Power and use1.1 Why an understanding of steam is neededSteam power is fundamental to what is by far the largest sector of the electricity-generating industry and without it the face of contemporary society would be dramatically different from its present one. We would be forced to rely on hydro-electric power plant, windmills, batteries, solar cells and fuel cells, all of which are capable of producing only a fraction of the electricity we use.Steam is important, and the safety and efficiency of its generation and use depend on the application of control and instrumentation, often simply referred to as C&I. The objective of this book is to provide a bridge between the discipline of power-plant process engineering and those of electronics, instrumentation and control engineering.I shall start by outlining in this chapter the change of state of water to steam, followed by an overview of the basic principles of steam generation and use. This seemingly simple subject is extremely complex. This will necessarily be an overview: it does not pretend to be a detailed treatise and at times it will simplify matters and gloss over some details which may even cause the thermodynamicist or combustion physicist to shudder, but it should be understood that the aim is to provide the C&I engineer with enough understanding of the subject to deal safely with practical control-system design, operational and maintenance problems.1.2 Boiling: the change of state from water to steamWhen water is heated its temperature rises in a way that can be detected (for example by a thermometer). The heat gained in this way is called sensible because its effects can be sensed, but at some point the water starts to boil.But here we need to look even deeper into the subject. Exactly what is meant by the expression 'boiling'? To study this we must consider the three basic states of matter: solids, liquids and gases. (A plasma, produced when the atoms in a gas become ionised, is often referred to as the fourth state of matter, but for most practical purposes it is sufficient to consider only the three basic states.) In its solid state, matter consists of many molecules tightly bound together by attractive forces between them. When the matter absorbs heat the energy levels of its molecules increase and the mean distancebetween the molecules increases. As more and more heat is applied these effects increase until the attractive force between the molecules is eventually overcome and the particles become capable of moving about independently of each other. This change of state from solid to liquid is commonly recognised as 'melting'.As more heat is applied to the liquid, some of the molecules gain enough energy to escape from the surface, a process called evaporation (whereby a pool of liquid spilled on a surface will gradually disappear). What is happening during the process of evaporation is that some of the molecules are escaping at fairly low temperatures, but as the temperature rises these escapes occur more rapidly and at a certain point the liquid becomes very agitated, with large quantities of bubbles rising to the surface. It is at this time that the liquid is said to start 'boiling'. It is in the process of changing state to a vapour, which is a fluid in a gaseous state.Let us consider a quantity of water that is contained in an open vessel. Here, the air that blankets the surface exerts a pressure on the surface of the fluid and, as the temperature of the water is raised, enough energy is eventually gained to overcome the blanketing effect of that pressure and the water starts to change its state into that of a vapour (steam). Further heat added at this stage will not cause any further detectable change in temperature: the energy added is used to change the state of the fluid. Its effect can no longer be sensed by a thermometer, but it is still there. For this reason it is called latent, rather then sensible, heat. The temperature at which this happens is called the 'boiling point'. At normal atmospheric pressure the boiling point of water is 100 ° C.If the pressure of the air blanket on top of the water were to be increased, more energy would have to be introduced it to break free. In other words, the temperature must be raised further to make it boil. To illustrate this point, if the pressure is increased by 10% above its normal atmospheric value, the temperature of the water must be raised to just above 102 °C before boiling occurs.The steam emerging from the boiling liquid is said to be saturated and, for any given pressure, the temperature at which boiling occurs is called the saturation temperature.The information relating to steam at any combination of temperature,pressure and other factors may be found in steam tables, which are nowadays available in software as well as in the more traditional paper form. These tables were originally published in 1915 by Hugh Longbourne Callendar (1863-1930), a British physicist. Because of advances in knowledge and measurement technology, and as a result of changing units of measurement, many different variants of steam tables are today in existence, but they all enable one to look up, for any pressure, the saturation temperature, the heat per unit mass of fluid, the specific volume etc.Understanding steam and the steam tables is essential in many stages of the design of power-plant control systems. For example, if a designer needs to compensate a steam-flow measurement for changes in pressure, or to correct for density errors in a water-level measurement, reference to these tables is essential.Another term relating to steam defines the quantity of liquid mixed in with the vapour. In the UK this is called the dryness fraction (in the USA the term used is steam quality). What this means is that if each kilogram of the mixture contains 0.9 kg of vapour and 0.1 kg of water, the dryness fraction is 0.9.Steam becomes superheated when its temperature is raised above the saturation temperature corresponding to its pressure. This is achieved by collecting it from the vessel in which the boiling is occurring, leading it away from the liquid through a pipe, and then adding more heat to it. This process adds further energy to the fluid, which improves the efficiency of the conversion of heat to electricity.As stated earlier, heat added once the water has started to boil does not cause any further detectable change in temperature. Instead it changes the state of the fluid. Once the steam has formed, heat added to it contributes to the total heat of the vapour. This is the sensible heat plus the latent heat plus the heat used in increasing the temperature of each kilogram of the fluid through the number of degrees of superheat to which it has been raised.In a power plant, a major objective is the conversion of energy locked up in the input fuel into either usable heat or electricity. In the interests of economics and the environment it is important to obtain the highest to the water to enable possible level of efficiency in this conversion process. As we have already seen, the greatest efficiency is obtained by maximising theenergy level of the steam at the point of delivery to the next stage of the process. When as much energy as possible has been abstracted from the steam, the fluid reverts to the form of cold water, which is then warmed and treated to remove any air which may have become entrained in it before it is finally returned to the boiler for re-use.1.3 The nature of steamAs stated in the Preface, the boilers and steam-generators that are the subject of this book provide steam to users such as industrial plant, or housing and other complexes, or to drive turbines that are the prime movers for electrical generators. For the purposes of this book, such processes are grouped together under the generic name 'power plant'. In all these applications the steam is produced by applying heat to water until it boils, and before we embark on our study of power-plant C&I we must understand the mechanisms involved in this process and the nature of steam itself.First, we must pause to consider some basic thermodynamic processes. Two of these are the Carnot and Rankine cycles, and although the C&I engineer may not make use of these directly, it is nevertheless useful to have a basic understanding of what they are how they operate.1.3.1 The Carnot cycleThe primary function of a power plant is to convert into electricity the energy locked up in some form of fuel resource. In spite of many attempts, it has not proved possible to generate electricity in large quantities from the direct conversion of the energy contained in a fossil fuel (or even a nuclear fuel) without the use of a medium that acts as an intermediary. Solar cells and fuel cells may one day achieve this aim on a scale large enough to make an impact on fossil-fuel utilisation, but at present such plants are confined to small-scale applications. The water turbines of hydro-electric plants are capable of generating large quantities of electricity, but such plants are necessarily restricted to areas where they are plentiful supplies of water at heights sufficient for use by these machines.Therefore, if one wishes to obtain large quantities of electricity from a fossil fuel or from a nuclear reaction it is necessary to first release the energy that is available within that resource and then to transfer it to a generator, and this process necessitates the use of a medium to convey the energy from source to destination. Furthermore, it is necessary to employ a medium that isreadily available and which can be used with relative safety and efficiency. On plant Earth, water is, at least in general, a plentiful and cheap medium for effecting such transfers. With the development of technology during the twentieth century other possibilities have been considered, such as the use of mercury, but except for applications such as spacecraft where entirely new sets of limitations and conditions apply, none of these has reached active use, and steam is universally used in power stations.Carnot framed one of the two laws of thermodynamics. The first, Joule's law, had related mechanical energy to work: Carnot's law defined the temperature relations applying to the conversion of heat energy into mechanical energy. He saw that if this process were to be made reversible, heat could be converted into work and then extracted and re-used to make a closed loop. In his concept (Figure 1.1), a piston moves freely without encountering any friction inside acylinder made of some perfectlyinsulating material. The piston isdriven by a 'working fluid'. Thecylinder has a head at one end thatcan be switched at will from beinga perfect conductor to being aperfect insulator. Outside thecylinder are two bodies, one ofwhich can deliver heat without itsown temperature ( T1 ) falling, theother being a bottomless cold sink at a temperature (T2) which is also constant.The operation of the system isshown graphically in figure 1.2,which shows the pressure/volumerelationship of the fluid in thecylinder over the whole cycle. As theprocess is a repeating cycle itsoperation can be studied from anyconvenient starting point, and weshall begin at the point A, where thecylinder head (at this time assumed to be a perfect conductor of heat), allows heat from the hot source to enter the cylinder. The result is that the medium begins to expand, and if it is allowed to expand freely, Boyle's law (which states that at any temperature the relationship between pressure and volume is constant) dictates that the temperature will not rise, but will stay at its initial temperature (Tl). This is called isothermal expansion.When the pressure and volume of the medium have reached the values at point B, the cylinder head is switched from being a perfect conductor to being a perfect insulator and the medium allowed to continue its expansion with no heat being gained or lost. This is known as adiabatic expansion. When the pressure and volume of the medium reach the values at point C, the cylinder head is switched back to being a perfect conductor, but the external heat source is removed and replaced by the heat sink. The piston is driven towards the head, compressing the medium. Heat flows through the head to the heat sink and when the temperature of the medium reaches that of the heat sink (at point D), the cylinder head is once again switched to become a perfect insulator and the medium is compressed until it reaches its starting conditions of pressure and temperature.The cycle is then complete, having taken in and rejected heat while doing external work.1.3.2 The Rankine cycleThe Carnot cycle postulates a cylinder with perfectly insulating walls and a head which can be switched at will from Being a conductor to being an insulator. Even with modifications to enable it to operate in a world where such things are not obtainable, it would have probably remained a scientific concept with no practical application, had not a Scottish professor of engineering, William Rankine,proposed a modification to it at thebeginning of the twentieth century [I].The concepts that Rankine developedform the basis of all thermal powerplants in use today. Even todayscombined-cycle power plants use hiscycle for one of the two phases oftheir operation.Figure 1.3 illustrates theprinciple of the Rankine cycle. Starting at point A again, the source of heat is applied to expand the medium, this time at a constant pressure, to point B, after which adiabatic expansion is again made to occur until the medium reaches the conditions at point C. From here, the volume of the medium is reduced, at a constant pressure, until it reaches point D, when it is compressed back to its initial conditions.电厂蒸汽动力的基础和使用1.1 为何需要了解蒸汽对于目前为止最大的发电工业部门来说，蒸汽动力是最为基础性的。

电动汽车产业分析毕业设计外文文献英文原文：Abstract - A vehicle is consider Green when it more environmentally friendly than the traditional petroleum combustion engine, in which includes any nontraditional vehicle like, HEV, Plug In, EV, Fuel Cell, Bio fuel etc. that improves fuel economy. The development of electric vehicle has been over a hundred years but failure to gain the public acceptance in various stages due to various reasons which explained・ While EV was never mass produced. Hybrid electric vehicle gains the momentum in recent years. Ford has launched its second generation of HEV and GM also announced the debut of the Volt in 2010. Comparing to the regular HEV, Plug in is the new trend in hybrid auto development due to extend travel range in electrical mode and a possibility of a zero emission as long as travel distance is less than charging threshold・ However, more recently, an electrification trend in automotive industry has been evolved and will revolutionize the industry. With the correct policy and government help and advancement of electric vehicle technology, the prospect of Electric Vehicle will be bright and the focus point of future development.Keywords 一electric vehicle, hybrid, plug in, green, historyINTRODUCTIONAs associated with energy independence and environmental issue, alternative fuel vehicle, especially Electric and Hybrid electric vehicle has become part of the government policy all over the world・ The united State mandates a stricter fuel economy standard・ China issued a new energy vehicle policy to accelerate & subsidize the deployment of electric this year and set a goal of 500k for 2011. Hong Kong also set a clear vision for EV application in the near future・As for the auto industry, a silent green resolution is undergo significant transformation after gasoline price rose significantly to exceed US$2 level and market demands for such vehicle. The industry introduced more fuel efficient HE Vs and less polluted vehicles to the market. As Oil price surged rapidly during the last few years, the phenomenon has pushed pure electric vehicle development regaining traction among automakers and governments・The consumer market has brought significant gain in alternative fuel vehicle as well as HEV and electric vehicles・ A HEV study (Fig. 1) conducted by Polk & Company indicated an upward trend of market share of HEV sales in United State and Western Europe・ An even bigger share of HEV and EV were predicted when they combined・ In fact, selection of HEV models from OEMs have grown from two (Insight & Prius) in 2000 to more than twenties as today. Sales of the HEV are in the fast track along with more than 300,000 HEV sold in 2007(2]. Further known commitments of HEV and electric vehicle from OEM will improve the HEV production even more・Adding plug-in and electric vehicle to the line up will strengthen and accelerate the current electrification trend・Chevy Vblt, the first plug-in hybrid, and a bunch of planned electric vehicles saluted for endconsumer in the North America will lead to a round of new energy vehicle in the market・HISTORY OF ELECTRIC VEHICLE DEVELOPMENTThe development of electric vehicle has a long history. Since the invention of electric motor, electric vehicle has been around for 150 years ・ From simple non-chargeable to modern state of art control system, the development of Electric vehicle can be classified into three stages: Early development stageElectric vehicle was considered among the earliest automobile and well ahead of combustion engine・ It dominated the vehicle registration with 3:1 comparing to gasoline vehicles in the late 1920s to 1930s and held most of the land vehicle performance record in early 1900s. It was a major transportation tool and widely used in the society for local transportation improved from horse carriages・Until 1930, electric vehicle leadership was overtaken by gasoline vehicle development and was never able to reclaim the status for following reasons: Maturity of Gasoline vehicle and can be mass produced at a reasonable cost・With the mass production of Model T & manufacture process revolution, vehicles became suddenly available to general public and proceed as a way to improve life; Gasoline vehicle took over as the leader and surpass electric vehicle both in performance and cost・ Infmstructiire improvement and demand of inter-city travel required a longer travel distance that was never able to exploit by electric vehicle before. Lacking of charge infrastructure development, reliable electricity transmission and limited travel distance, electric vehicle no longer suited for consumer demand and lost the edge to regular gasoline vehicle・Limited or no electrical infrastructure support forced the resignation and abundance of earlier electric vehicle.Widely discovery of gasoline in the sate and ready availability of cheap fuel also contributed the spread of gasoline vehicle・ Petrol in the 1930s provided a direct cheap source of energy for vehicle transportation. It could be carried around by container which enabled and extended the mobility of owning a vehicle・B.Midterm development (1930s-1980s)Electric vehicle production and development came to a halt as personal transportation after combustion engine took over in 1935・ Political sensitivity with OPEC created a necessity of energy independence during the 1960s and 1970s・U.S Government and environmentalist reintroduced tougher fuel efficient standard for the industry and ignited a board interest in electric vehicle in the period・ Energy crisis in early 70s driven the US postal service placed a large order of 350 EV test fleet. It is the highest node of midterm development. However, partly due to limited performance, other governmental priorities, lack of board infrastructure support and range of corporation participation, the development quiet down quickly during this period・C.Modern DevelopmentModern EV development was dominated by EVI who produced by GM for fleet application. Following a program funded by Department of Energy, Ford developed EV Ranger pick up truck, Toyota provided Rav4 EV and Honda had an EV available as well during late 1990s and early 2000s・Unfortunately, this short surge of EV availability did not realized into commercialproduction because of a complicated issue of politics, economic, education and technology that includes vehicle production cost and safety concerns. EVI, Ranger, Rav4 and Honda EV were intended for fleet test only, almost all the vehicles has been discontinued, destroyed and recycled ・ Only a handful of electric vehicles were survived under the hands of EV enthusiasts.D.Modern HEV developmentHowever, in 1999 and early 2000s, a new type of electric vehicle emerged from pure electric vehicle・ Honda introduced the first HEV, Honda Insight, to the US Market that brought another milestone in auto industry. With brisk market acceptance and success of the Prius, HEV technology shows it maturity and potential. Ford introduced the first American hybrid elective vehicle, Escape SUV HE\；during the 'Manilattan on a Tank" event and registered 600 miles/tank in congestive city traffic that opened a new era of competition in US among HEVs. By year of 2008, the HEV sales were more than 2.5% for total sales volume. In deep, the next generation of HEV from Toyota, Honda and Ford has introduced into 2009 with further refinement along updated technology. Fuel efficiency has improved as well.Toyota is the clear leader in the HEV arena base on volume and range of models with it u syiiergy drive system"・ Honda and Ford are right behind with their offering in full hybrids・ GM offers its "two mode" technology in hybrid passenger cars and trucks as well.E・ Future DevelopmentAs gasoline price rise rapidly, combined with environmental concern, the society renews the call for social responsibility. Electric Vehicle and other AFV suddenly becomes popular again・With announcement of the Chevy Volt plug-in concept couple years ago and pure electric vehicle fi'om Nissan, a new round of EV devulopment has resuiTected into OEM’s cycle plan in the up coming years・ The fruit of this EV trend will be seen in the next three years・ Comparing to previous electric vehicle development, there are a few factors that will ensure this initiation be successful in the future:Vehicle operators are the direct target customers of developing EV. Market driven approach always creates competitive and attractive products at reasonable cost and performance・Early technology and environmental adopter will the initial leaders and users・ They are willing to support and has the capability to influence the success・ Also various education programs and EV initiatives transform general understanding of fuel efficient vehicles and their benefits・Warm acceptance of electric vehicle is high in the coming years.Cooperation in charge station and infrastructure development has gained attention at different level. Various business models are being explored・ The industry and government are confident that final plan will reach prior to the mass launch of electric vehicle・Energy storage technology improvement makes lithium battery application became safe in vehicle・Sophistication of system management upgrades and improves electric vehicle to a comparable level of combustion engine・Lastly, proper government policy provides a development foundation for the industry・Special tax incentives and subsidy will offset consumer burden for purchasing electric vehicle・ It is a confident vote for the product whengovernment is willing to provide financial and strategic support.III. CONCLUSIONLike many emerging technology, electric vehicle development and application have been around for a long time, but until recently, the technology has not really taken off. Even though HEV started as a good alternative to gasoline vehicle and well publicized by the media, but it only represented as the intermediate step or near term solution. Government regulation and environmental prospect, in particular will drive the adoption of transportation electrification. Electric vehicle will be the final goal. Along with new electric vehicle development on the way, it will also introduce tremendous opportunity in associated technology especially in Power electronics. We shall utilize 什lis opportunity and contribute to the green trend・中文译文：引言：一辆汽车被认为是绿色的，假如这部车比传统燃油内燃机对环境更友好，而这种汽车包含了任何非传统的汽车，如混合动力汽车，包括EV,燃油电池，生物燃料等提高了燃油经济性。