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DLN2.6燃烧室

DLN2.6燃烧室
DLN2.6燃烧室

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1.0 Purpose and Scope

The DLN2.6 combustor is fully premixed throughout the entire operating range from first fire to baseload. This is accomplished through fuel nozzle staging and fuel split scheduling. There are four distinct injection points. The PM1 Nozzle, 2 PM2 Nozzles, 3 PM3 nozzles and the quaternary gas pegs. The PM1 nozzle is located in the center of the combustion endcover, while the PM2 and PM3 nozzles make up the outer nozzles. The quaternary pegs are located in the forward casing upstream of the nozzle /cap assembly. The nozzle configuration is very similar to the DLN-2 combustion system w/ the exception that there is a center nozzle added for NOx turndown, and the outer 5 nozzles are staged as a 3 and 2 arrangement , unlike the DLN-2 which has a 4 and 1 nozzle staging arrangement. The diffusion or primary fuel on the DLN-2 combustion system has been replaced by a continuous “hot” compressor discharge purge to the diffusion side of the outer 5 nozzles.

The 7FA/7FA+ systems have the same combustion hardware , while the 7FA+e to reduce overall pressure drop has an increased volume in the head end of the combustor. The endcover is 1“ larger in diameter than the 7FA/7FA+ DLN2.6 systems. The 7FA+e outer nozzles have a cast swirler with integral full fairings as shown in Appendix B.

The loading sequence is shown below. Calculated combustion reference temperature is used to Mode switch at full speed.

DLN-2.6

TYPICAL

LOADING

(firing to 16% speed)

SEQUENCE

(16% to 95 % speed)

(95 % speed to TTRF1 switch #1)

(TTRF1 switch #1 to #2)

(TTRF1 switch #2 to #3)

(TTRF1 switch #3, brief duration)

(TTRF1 switch #3 + a time delay to #4)

(Above TTRF1 switch #4 to base load)

e john cole 1998

A typical unload is shown below. Each mode transfer during the unload is triggered by a combustion reference temperature switch point (same as used during loading) minus a deadband temperature (typically

50 - 80 F) which prevents unexpected toggling between Modes due to load /TTRF swings in the system.

A breaker open event will drive the unit to M1 , but it will first give the PM2 nozzles an open loop fuel command to sustain flame while the load is being shed on the unit. After a specified amount of time the percentage of fuel to the PM2 nozzles will be cut off and all the fuel will be driven to the PM1 nozzle.

DLN-2.6

TYPICAL

SHUTDOWN

SEQUENCE

1.1. DLN TUNING KIT SETUP

Please use the Installation and Operation Manual for the Combustion Dynamics

Measurement System. This manual details the setup, configuration and troubleshooting of the system

The DLN2.6 system typically sees two distinct axial tones with frequencies of 100-125 Hz and 130-150 Hz . These are called “cold” and “hot” tones respectively. The 100-125 Hz or “cold” tone is usually seen at lower firing temperatures in M5 and M6, toward more “even” fuel splits (each fuel nozzle receiving the same amount of fuel), or in M6 with “high” PM1 split (eg:15-16% PM1) The “hot” tone can vary between 130-150 Hz depending on the fuel nozzle peg hole definition, the fuel nozzle split and the combustion reference temperature.

A third frequency seen in the DLN2.6 combustor occurs at 2300-2500 Hz and is a radial or “screech” tone. It is audible and can be best described as a high pitch whine. The tuning kit is capable of detecting screech but due to an attenuation from the approximately 25’ of tubing between the chambers and transducers the levels are significantly reduced. Screech is usually detected at even fuel splits and lower firing temperatures in M5 and M6 (it has only been detected once in the field on a 2.6 system and moving off even split in M6 (PM3/PM2 split) eliminated the tone.)

Screech is very destructive and levels of 1-2 psi will cause high cycle fatigue which will quickly crack welds and lead to component hardware failure. It is imperative that the screech be tuned to less than 0.25 psi pk-pk 16 scan average

Note: Date and Time synch the tuning kit, and the processor you are using for data summary to the MarkV panel.

FFT Bands

The tuning computer has three break frequency’s which will enable better resolution of the dominant tones. The frequency ranges for the 2.6 are as follows:

Peak 1 <130 Hz Peak 2 130>220Peak 3 >220

The break frequency’s are set to detect the expected frequency’s in the combustor based on laboratory and Field testing, as well as to standardize the data output from site to site.

Note: the “cold” and “hot” tones are very close to each other, if the breakpoints are set on a dominant frequency the max amplitude may be clipped. Try changing the breakpoint frequency and scanning again , recheck amplitudes.

“Hot & Cold tone response in Mode 5 and Mode 6“

The “hot” - 130-150 Hz and “cold” tone 100-125 Hz are excited and damped by certain changes in system settings , the following list gives a quick guide .

Note: Quaternary is used ONLY to damp “hot tone” dynamics if none are present do not use it.

In Mode 5, Nox emissions may decrease slightly with addition of quaternary fuel, as the outer nozzles are leaned out and the quaternary is added. In Mode 6 - Nox will not be affected by adding quaternary. If dynamics are present and quaternary is added it may appear to reduce Nox , it is most likely due to the unmixedness /dynamics that were present before and were slightly increasing Nox .

“Acceptable Dynamic Levels” - - Although every effort should be made to stay within the expected and preferred dynamic levels , it is realized that due to system - system differences this is not always possible

1.2 REQUIRED STARTUP INSTRUMENTATION / MEASUREMENTS

?Emissions Monitoring / CEMS equipment

Emissions monitoring equipment is required for DLN 2.6 tuning and optimizing split schedule.

(NOx in ppmvd, CO in ppm and O2 in %). Mode 5 and Mode 6 split optimization must be

completed with emissions and dynamics present. The goal is to optimize the Nox emissions while maintaining acceptable dynamic levels. Emissions are also needed as a diagnostic tool to ensure the combustion system is operating normally and as expected.

Convert Nox raw to 15 % 02 by the equation below :

NOx @ 15 % O2 = Nox (raw) * ( 20.9- 15%) / ( 20.9 - O2%)

?Dynamics Monitoring system - (detailed in above section)

All 14 chambers must have working PCB’s or unit must NOT be loaded –Failure to monitor

EVERY combustion chamber may cause damage to hardware

?Startup strainers – witch hats/ y-strainer

?It is imperative that startup strainers be used. This is the only protection the combustion system has to ensure no contaminants enter the system. The fuel nozzles

will entrain any debris that enters the system. Fuel nozzles will be plugged which can

lead to nozzle damage.

The startup strainers are detailed in AO179 in the drawing systems specification, please refer to this document for a thorough explanation of strainer specifications.

Note : The DLN2.6 PM2 manifold witches hat strainer exhibits 25 psid at FSNL – clean. The cause of this is being investigated.

?Manifold Pressure Instrumentation

All gas manifolds should have a DP transmitter with the high side attached to the PM1, PM2, PM3 and Quaternary Manifold respectively and the low side attached to a CPD source. Due to nozzle affective area sizing /control valve calibrations for each valve it is important to verify the pressure at the PM3 and PM2 manifolds. The DLN2.6 system currently does not optimize at an even split on the PM3/PM2 due to dynamic constraints. The unit is loaded off even split during the initial tuning to further reduce the risk of part load dynamics as described in detail in a later section. In M5 without quaternary fuel the PM3 and PM2 nozzles will theoretically show even manifold pressures at a 60/40 % PM3/PM2 split. –this must be verified by the DLN TA.

?DLN Audit / Red Flag review Complete

Ensure the DLN audit and subsequent action items that impact the system are closed prior to first fire of the unit..

1.3. FUEL GAS TEMPERATURE

Each requisition has been sized based on the Engineering entry for fuel gas temperature/ wobbe#, as defined below. If the site is a heated requisition it is important that the unit is run within the acceptable +/- 5 % wobbe# limitation and there are provisions that will limit the system to M4 in the event of loss of fuel gas temperature. A system tuned for 365 F fuel gas temperature may be dynamically inoperable at 65 F – if the unit is left in this state severe damage to combustion hardware and hot gas path may result.

Note: a system “tuned” to acceptable levels of “hot tone” at 350 F will have high levels of “cold tone” when the gas temperature is out of the acceptable wobbe limits specified. Conversely a system tuned for cold gas (~60) F will have high levels of “hot tone” when the gas temperature exceeds the acceptable wobbe limits of +/-5%.

The graph below represents the dynamic response w/ change in fuel gas temperature. It does not attempt to show amplitudes but, shows the trend of dynamics with FGT as well as the dynamic response. The “cold tone” comes in very strong very quickly, that is why it is advisable to change fuel split in ? % increments.

M6 - Dynamics reponse to Fuel Gas Temperature

Even PM3/PM2 split

?Modified Wobbe Index

During specified cold and hot fuel modes as defined below in the startup requirements for the 2.6 system, gas fuel temperatures shall be maintained such that the resulting Modified Wobbe Index value is within 5% of the applicable cold and hot target values.

Where: MWI = LHV / SQRT ( T *Sg)

MWI = Modified Wobbe Index (temperature corrected)

LHV = Lower Heating Value of Fuel (BTU/SCF)

T = Absolute Temperature (R)

Sg = Specific Gravity of fuel relative to air at ISO Conditions

?Startup requirements

For cold fuel requisitions (65-150 F) there are no fuel gas temperature limitations on how the unit is loaded. The Wobbe index will be within the specified +/- 5% .

For heated requisitions (250 - 365 F ) the following is required :

? Ignition until the M1 transfer temperature shall be cold fuel

? Once M3 is established the controller will send a signal via the Ethernet/modbus link to the DCS to start fuel heating

? M4 shall not be initiated until the required fuel gas temperature is reached. A lockout will be given to the controller to disable further loading until this is done. This limit shall be defined during the testing of the first heated 7FA DLN2.6 system.

For requisitions with fuel gas temperature from 120 - 250testing is required to define the limitations on the system due to PM1 nozzle area and dynamics response to variable fuel gas temperature

1.4 REQUIRED COMBUSTION FIELD COMMISSIONING DATA

?Tuning Spreadsheet - While loading the unit record test points at each 5 MW step, record test points during DLN tuning (split checks). Use the spreadsheet in Appendix A. It specifies the

required parameters to be logged. This data will help the TA on site to keep a record of tuning

and aid in determining the optimum split schedules for the machine. Also once the unit is

completely “tuned”, perform a slow unload from Baseload Mode 6 to just before the transfer to

Mode 5. Record data (emissions/dynamics/Machine parameters) every 5 MW. This will be the

final “tune” emissions and dynamics and can be easily referenced Emissions or Dynamics on

the control curve need to be diagnosed in the future.

?16 scan average steady state dynamic data – At each tuning point either save to file or print

a 16 scan average and include the relevant data in the tuning spreadsheet.The following are

the DLN data sheets needed back to engineering after final split schedules are installed:

1.) M4 dynamics data at the transfer point from M4-M5

2.) M5 dynamics data at the transfer point from M5-M6

3.) M6 dynamics data at the transfer point from M6 - M5

4.) M6 dynamics data Baseload

5.) M6 dynamics data Baseload w/ full steam injection (if applicable)

6.) Baseload dynamics data on oil operation

?DLN2.6 Split schedules - Record the as left split schedules in the sheet provided.

All data to be included in the assigned PAC case – it will be stored in a database for future reference. When DLN2.6 units are started in the field, operational data can be collected. This data will be helpful to the TA during tuning, troubleshooting and as a record of history for the site. The data should be sent as an addendum to the appropriate PAC case and logged for future reference.

An electronic copy of the tuning spreadsheet and DLN2.6 template can be forwarded at the start of each

PAC case to the DLNTA on site, to standardize the data from site to site.

1.5 TUNING PROCEDURE:

The section below will guide a DLN TA through the tuning procedure. This procedure should be used with the complementary DLN2.6 controls tuning document. It will only guide a TA through the

specific combustion tuning requirements.

?Check TTRF Calculation

Use the UT4 verification standard, and the TTRFPC calculation program to verify that combustion reference temperature is being calculated correctly. The DLN2.6 system changes Modes and split schedules based on TTRF.

Incorrect TTRF calculation will cause the turbine to run off its known operational curve, this can lead to serious damage of combustion hardware and hot gas path.

?Verify Exhaust Control Curves

ENSURE THE CORRECT CONTROL CURVES ARE BEING USED. Combustion dynamics are very sensitive to temperature, the wrong curves will cause the combustor to run off its intended schedule, and the

unit may exhibit unacceptable dynamic levels. Nox emissions are affected as they are directly proportional to the turbine firing temperature. Verify TTXM =TTRXP = TTRX at baseload. TTRXP identifies the

CPD/CPR temperature curve. The TTRXS curve will control the unit only in the event of CPD loss, this is the backup control curve and will either be based on FSR or DWATT control.

?Simple Cycle Control Curve

The DLN2.6 combustion system does NOT run on the Simple Cycle control curve. Verify that it is not operator selectable, and disabled in code.

?Verify Expected Machine Parameters

Once the unit is loaded verify that the expected controlling machine parameters are as expected

CPD,TTXM,TTRF1, CPR

?Minimum Inlet Guide Vane Angle - For 7FA+e only

In Mode 1 the PM1 nozzle takes all of the fuel. The PM1 nozzle must maintain an acceptable Pressure drop across the nozzle for dynamics constraints. This limits the total area of the Nozzle. To enable operation over the entire guaranteed ambient range any unit with Inlet Bleed Heat, will use a 42 deg. IGV angle.

1.6 Tuning GAS ONLY DLN

2.6 SYSTEMS 7FA/7FA+/7FA+e (Steam Injection Instructions to be added at a later Date)

Tuning Tips :

?Take data every 5 MW and input into spreadsheet

?Record all split checks / or if higher than acceptable dynamics comment on the spreadsheet - note frequency / amplitude and max can (previously provided on page 5)

?In M3 and M4 -- increase / decrease PM1 % split as necessary to decrease dynamic levels, attempt to stay close to default values. Maintain 2% margin from maximum dynamic levels (refer to section on M3 and M4 below for more detail)

?Ensure the default split schedules are used as the initial starting point

?Attempt to maintain +/- 2 % split margin from dynamics in M5 and M6 - although this may not always be possible and maintain Emissions compliance

?Ensure emissions are reliable. The CEMS on site are notorious for inaccuracies. M5 and M6 will need to be tuned with a reliable emissions

monitoring system.

?The “hot” and “Cold” tones can be close to each other. Take a 16 scan average at the indicated breakpoints above. If the frequency’s are close to each other , move out the breakpoint and take another scan. Check and see if the dominant tone has changed

Fire - Mode 3

Description:

The PM2 and PM1 nozzles are fueled during the firing sequence. Approximately 30% of the fuel is ported to the PM1 nozzle. The PM2 nozzles are fueled to ensure that cross firing of the unit occurs. The PM1 nozzle located in the center of the fuel nozzle arrangement will ensure a stable ignition and warm-up sequence

occurs. At approximately 16% turbine speed the unit is transferred to Mode 2 (2 PM2 nozzles only) for acceleration up to 95% speed.Tuning:

The firing FSR (FSKSU_FI) and the warm-up FSR (FSKSU_WU) may need to be adjusted if the unit fails to light or the unit does not crossfire. Adjustments have been made which change the M3-M2 transfer point from warm-up to 16% speed to ensure combustor crossfire and stability.

? The PM2 nozzles due to their location near the crossfire tubes once lit will crossfire continuously to the

other combustion chambers, until pressure differences combustor to combustor are decreased.Crossfiring and ignition of all chambers should take 1-2 seconds once flame is initially established.

16% SPEED TO 95% SPEED - Mode 2 (7FA/7FA+)

The unit accelerates in Mode 2 up to 95 % speed. If the spreads from warm-up to 70% speed are +150 F and the average exhaust temperature is below 850 F increase the FSRMIN to the unit between those two speed setpoints.

M2 - M1 transfer

During the transfer a transient 2-4 psi pk-pk ~156 Hz is seen as the PM2’s are blowing out and the PM1

nozzles ignite. Spreads in Mode 1 are usually below 20 F , if TTXSP1 >100 F at FSNL its indicative of a can blown out.

The unit will not crossfire in Mode 1 due to the position of the flame in the center burner tube, if spreads or flame detectors indicate a can blown out select STOP and give the unit a fired shutdown.

Take a view2 during the transfers and record any dynamic transients (note frequency and amplitude)

Mode 1

Description:

In Mode 1 all the fuel is being ported to the center (PM1) nozzle. This is a quiet mode dynamically.Fuel gas temperature must remain 50F above the dew point as this is still a fully premixed mode Expected Combustion Parameters throughout Mode 1:Dynamics < 1.0 psi pk-pk (varied frequencys)TTXSP1< 25 F FD_intens_n >80 Counts NOX 20-60 @15% O2 ppmvd CO 50-250 ppmvd

Expected Nox/CO vs Combustion Reference Temperature:

0.010.020.030.040.050.060.0

1300

1400

1500

1600

1700

TTRF1 ( combustion Reference Temperature)

I S O N o x @15% O 2 (p p m v d )

0.050.0

100.0150.0200.0

250.0C O (p p m v d )

7FA+ DLN2.6 @ 42deg. IGV's ----M1

Concerns:

The PM1 nozzle is sized such that there is sufficient pressure drop across the Nozzle. Each requisition is sized to enable the PM1 control valve to remain critical. On a cold day the transfer point from M1- M3 will be the highest fuel flow to the PM1 nozzle. Any increase in transfer temperature may cause the valve to go non critical at the min ambient rated condition when the unit is running minimum upstream pressure.

M1 - M3/ M3 - M1 transfers: (values are reference only -please refer to controls standard for updated schedules)

FXKTS11615FXKTS1DB

-60

DLN2.6 7FA+ Transfer from M3 - M1

2040

6080100120Time F S R P M 1_P C T ,F S R P M 3_P C T ,D W A T T ,T T X S P 1

0.40.81.21.622.42.83.23.6

4

D y n a m i c s - M a x A m p l i t u d e 1s c a n p s i -p k -p k

Concerns:

Currently the M3-M1 transfer is being “tuned”. There is usually a 7-10 MW dip during the transfer from M3-M1. It is very important that the transfer temperatures be maintained and not increased, due to gas pressure limitations that may exist on cold ambients max load M1 (the transfer point from M1 – M3 would be the worst case, as it would require the highest fuel pressure)Dynamics are < 1.0 psi pk-pk throughout the transfer

Mode 3

Description:

The unit transfers from M1-M3 at approximately TTRF=1615. In Mode 3 fuel is ported to the PM2 and PM1nozzles. Ensure that there is enough flow to the PM1 nozzle. This nozzle acts like an anchor and keeps the system stable. If the PM1 split is too low 156 Hz dynamics will increase (2-4 psi). To decrease dynamics increase the PM1 split. Usually this occurs from 1650-1900 F. If split is changed to decrease dynamics,perform another M1-M3 / M3- M1 transfer to ensure reliability.

Split Schedule Constants For Reference only ----- Schedules listed in controls specification:The Plot below defines the upper and lower limits for the PM1 flow split schedule in Mode 3

Expected Combustion Parameters: Dynamics < 1.0 psi pk-pk (varied frequencys)TTXSP1< 60 F FD_intens_n >80 Counts NOX 20-70 @15% O2 ppmvd

CO

200-800 ppmvd Expected Nox/CO vs Combustion Reference Temperature:

P M 1 S p l i t S c h e d u l e - M o d e 3

2

222233333444445555561500

1550

1600

1650

1700

1750

1800

1850

1900

1950

2000

2050

2100

C o m b u s t i o n R e f e r e n c e T e m p e r a t u r e (d e g . F )

P M 1 % F l o w

7FA+ M3 operation 48 deg IGV's

0.0

10.0

20.030.040.050.060.070.01600165017001750180018501900195020002050

Combustion Reference Temperature (TTRF1)

I S O N o x @ 15% O 2 (p p m v d )

0.0100.0

200.0300.0400.0500.0600.0700.0800.0C O (p p m v d )

M4 OPERATION

Description:

In Mode 4 fuel is ported to the three PM3 nozzles and 1 PM1 nozzle. The Unit transfer from M3 - M4 at approximately 2000 deg. Combustion reference temperature. The temperature needs to be high enough to ensure the 3 PM3 nozzles maintain a stable flame. The PM1 flow is kept high enough to ensure the nozzle will anchor the combustors during the transfer from M3 - M4.

Dynamics in Mode 4 can be tuned below 1psi pk-pk. Again, the knob is similar as in Mode 3. Dynamics can be as high as 3 - 5 psi “hot tone” ~150 Hz, to decrease this frequency increase the PM1 percent fuel https://www.doczj.com/doc/1d4267657.html,ually only a

few percent will reduce levels below 1 psi pk-pk 16 scan average.

Allowable Adjustments of PM1 nozzle from Nominal Splits listed in controls specification: (values are for reference only)

The following graph defines the upper and lower “tuning” limits for the PM1 Nozzle in Mode 4.

PM1 % Split Schedule - Mode 4

2224262830323436384042444648% P M 1 F l o w S p l i t

Expected Combustion Parameters in Mode 4: Dynamics < 1.0 psi pk-pk (150 Hz)TTXSP1< 60 F (usually 40-50 F)FD_intens_n >80 Counts NOX 20-70 @15% O2 ppmvd

CO

200-800 ppmvd Expected Nox/CO vs DWATT:

7FA+ M4 Emissions

48 deg IGV

46.0

48.0

50.0

52.054.0

56.0

58.0

DWATT

N o x (p p m v d )

0.050.0100.0150.0

200.0

250.0

300.0

C O (p p m )M4 - M5/ M5 - M4 transfers:

M5 - M4 transfers had to be tuned initially when the 7FA /7FA+ full fairings were released.

The transfer temperature had to be increased going into M5 to provide increased margin on blowout.

Since the PM3 nozzles need to keep the machine stable throughout the transfer as the PM1 split is ramped during the M5 – M4 transfer, increasing the PM3 to an independent split set point of 70% helps keep the machine lit during the transient until the PM1 nozzle flow is large enough to stabilize the combustor.The M4 - M5 transfer also sets an independent split setpoint of 70% during the transfer.

Take a view2 during the transfers and record any dynamic transients (note frequency and amplitude)

M4 - M5 TRANSFER

00.511.522.533.544.550

0.00050.0010.00150.0020.00250.0030.00350.0040.0045

0.005

Time -h.mmss(.0015-.0025 =10 sec)

m a x c h a m b e r a m p l i t u d e p s i -p k -p k

F S R P M 1_P C T ,F S R P M 3_P C T ,D W A T T ,T T X S P 1,F S R

M5/ M5Q OPERATION

Description:

In Mode 5 the 3 PM3 and 2 PM2 nozzles are fueled. Quaternary may be needed to suppress “hot tone”dynamics.

Mode 5 intentionally has a very small operating window typically from 2110 -2220 TTRF1.

? Check PM3 and PM2 manifold pressures - find out what PM3/PM2 split even pressure in the manifolds

occur. This will usually (not always) correspond to the lowest Nox value. If even pressures does not occur at 60%PM3 (5 nozzles are being fueled –(3PM3 to 2 PM2 nozzles would mean 60% is evenly fueled ) this should be investigated

? Are strainer DP’s higher in one fuel circuit than the other ? This may cause even split to shift ? Is there a distinct dynamic signature shift from upper to lower combustion chambers ? If the

fuel is not being evenly fed to either the PM3/PM2 circuit it may be identifiable as a frequency shift or amplitude gain from top to lower chambers.

? Re-check gas valve calibration. This is the most likely culprit and can be easily identified when

the unit is offline. ** If the calibration does change so will even split ***

? Due to dynamics constraints (may occur on “cold fuel – Low FGT 60-150F ” systems) it may not be

possible to verify even pressures .? Disable Quaternary before transferring into Mode 5 - currently software should have Quaternary

valve disabled Until units w/ FGT = 365 are tested in the field it is safer to delay quaternary than have it enabled when “cold

tone” is present as it is excited by quaternary and can easily JUMP to ~10 psi w/ the addition of quaternary fuel.

? Once into Mode 5 check dynamic levels

? if “hot tone” dynamics are > 4.0 psi pk-pk turn on quaternary - TIL 1191 states 6 -11% . Maintain this criteria.

? If dynamics are < 4.0 psi pk-pk “hot tone” move towards more “even” PM3 / PM2 split.

? If dynamics are “cold tone “(~125 Hz) and > 1.0 ps pk-pk 16 scan average move away towards richer PM3 split from even PM3/PM2 split (manifold pressures will determine

“even” split)

? Do a split check +/- 2 % from nominal split

? Find optimum Dynamics / Emissions

? when doing split checks move in ? % increments

Ensure the transfer from M5 - M4

? Unload unit slowly in 2 MW increments to just before the M5 – M4 transfer point (ensure M5 is forced >1)

? record data at each 2 MW interval

? check emissions / dynamics

? Decrease load another 2 MW below transfer point ( record data point)

? examine CO /Nox /Dynamics

? If CO > 20 ppm it indicates lean combustors

? Increase PM3 split in ? % increments up to 4% from even

PM3/PM2 pressure and record data. (Maintain PM3 split no more

than +4% from even PM3/PM2 split.)

? If ISO Nox @ 15% O2 < 4 ppm it indicates lean combustors

? Increase PM3 split in ? % increments and record data. (Maintain

PM3 split no more than +4% from even PM3/PM2 split.)

? If 19Hz Dynamics > 2.0psi pk-pk 16 scan average it indicates lean

combustors (Maintain PM3 split no more than +4% from even PM3/PM2

split.)

? Manually force transfer from M5 -M4 and examine the view 2

? If the transfer failed examine where the spreads increased \ flame detectors intensities dropped or went to 0. – Ensure all software standards have been implemented. The M4 – M5 and M5

– M4 transfers incorporate a PM3 independent split setpoint during the transient. The PM3

split will drive to 70% to hold the combustors as the PM1 nozzle is being enabled/disabled.

? If TTXSP1 increased as the PM1 was prefilling but before it had started to ramp up then it is a good indication that the PM3’s blew out before the PM1 nozzle could ramp

up and hold the unit. (Ensure the unit has an independent split setpoint of 70 % PM3

during the transfer). Increase the PM3 split setpoint at the minimum Mode 5 point

(just before transfer to Mode 4). Maintain criteria of no more than +4% from even

PM3/PM2 pressure.

? If TTXSP1 increased after the PM1 valve had almost ramped to its intended position, it is likely that the Transfer out temperature may need to be increased.

Once back in M5

? load unit just below transfer to M6

? Do a split check +/- 2 % from nominal split

? Find optimum Dynamics / Emissions

Allowable Adjustments of PM3 nozzle in Mode 5 from Nominal Splits listed in controls specification:

This is solely dependant on Dynamics --- the best emissions will be at even PM3/PM2 split and should be relatively flat +/- 2% from this point – *but if “cold tone” dynamics are present they will prevent running even PM3/PM2 split*

Expected Combustion Parameters: Dynamics < 3.0 psi pk-pk (130-150 Hz),<1.0psi pk-pk (100-125 z)TTXSP1< 60 F (usually ~40-50 F)FD_intens_n >80 Counts NOX 4 - 13 ppm @15% O2 ppmvd

CO

< 1.0 ppmvd M5 - M6/ M6 - M5 transfers:

Typically this transfer is very quiet. All nozzles are fueled in Mode 6. During the transfer from M5 - M6 the

center nozzle is fueled. Take a view2 during the transfers and record any dynamic transients (note frequency and amplitude)

M6 / M6Q OPERATION

Description:

55

565758

596061626364

651875

190019251950197520002025205020752100212521502175220022252250

Combustion Reference Temperature (deg. F)

% P M 3 S p l i t

Assume Even Pressure = 60 % --if not schedule is moved based on even Manifold PM3/PM2 Pressure

In Mode 6 all of the nozzles are fueled. Optimum Emissions theoretically will occur when all the fuel nozzles have the same fuel to air ratio (f/a). This will occur once the PM1 nozzle reaches about 16.5 % fuel split. This is unlikely as once the PM1 nozzles receive ~ 15.5 % flow split, 100/125 Hz dynamics (cold tone) is excited.

The dynamic tones in Mode 5 are a good indication of what the levels will be in Mode 6. If “hot “ tone dynamics are dominant, once the center nozzle is fueled the system will become “softer”. The term “softer”essentially refers to the responsiveness of the system when the F/A ratio in the outer nozzles is decreased, the resulting drop across the nozzle is decreased , decreasing the overall Pressure ratio across the outer nozzles. This will induce the combustors to exhibit more of the 100/125 Hz “cold” tone dynamics.

NOTE : Once the center nozzle attaches the dynamic level may go from 1 - 6 automatically.

If this happens reduce the fuel to the PM1 nozzle quickly in 1 % increments until the tone is gone.

There may be a hysteresis effect, meaning that you may need to reduce the PM1 further than the original split where the dynamics first increased to remove the dynamics. Record dynamics levels and frequency and stay at least 2% below this split setpoint

Mode 6 Tuning:

Disable Quaternary before transferring into Mode 6

until units w/ FGT = 365 are tested in the field it is safer to delay quaternary than have it enabled when “cold tone” is present as it is excited by quaternary and can easily JUMP to ~10 psi w/ the addition of quaternary fuel.

The optimum dynamics / emissions split schedules currently do not optimize at even PM3/PM2 manifold pressures due to “cold” tone dynamics.

Before transferring to Mode 6 –verify where even occurs in the PM3 / PM2 Manifold

Use Default split schedules in Mode 6 – Ensure that the split schedules in the unit are

Per the controls standard – and the PM3 / PM2 split schedule is corrected for even manifold pressures on a site to site basis.

Once the unit is transferred to Mode 6

1. Evaluate Emissions / Dynamics at the M6 transfer in temperature

SPLIT CHECK for dynamics / emissions

? Evaluate Dynamics (frequency and Amplitude)

? If dynamics less < 2 psi pk-pk (16 scan average)

? Perform a PM3/PM2 split check +/- 2% split

? Perform a PM1 split check at optimum PM3/PM2 split , +/- 2% split

These checks will evaluate dynamics and emissions margin

? If dynamics are dominated by “hot” tone

? Decrease PM3 / PM2 split towards even

? Increase PM1 Split setpoint

? Turn on quaternary (TIL 1191 – states quaternary levels to be maintained within 6 – 11 %)? If Dynamics are dominated by “cold” tone

? Increase PM3 / PM2 split away from “even”? Decrease PM1 split setpoint

2. Increase Load in 5 MW steps

? Every 5 MW take a complete test point recording Emissions/Dynamics/ machine parameters listed

in Appendix A 3. Hold at ~ 65 deg IGV’s and perform another split check 4. Increase Load in 5 MW increments 5. Once the unit is at Baseload

? Perform a split check

? Ensure all vital machine parameters are as expected (i.e Are we are operating on expected control

curves ? Is DWATT/CPD/CPR/TTXM/FSR/LVDT Feedback on valves as expected ?)? Optimize for emissions and dynamics (know the site emissions guarantee)

? Attempt to maintain a PM3/PM2 and PM1 split schedule that is at least 2 % away from

unacceptable dynamics levels (Section 1.1 states expected and max dynamic levels)

Allowable Adjustments of PM3 nozzle in Mode 6 from Nominal Splits listed in controls specification:

This is solely dependant on Dynamics --- the best emissions will be at even PM3/PM2 split and should be relatively flat +/- 2% from this point – *but if “cold tone” dynamics are present they will prevent running even PM3/PM2 split*

PM3 % Flow - Mode 6

555657

58

5960616263

64

651875

1900

1925

1950

1975

2000

2025

2050

2075

2100

2125

2150

2175220022252250

% P M 3 S p l i t

Assume Even Pressure = 60 % --if not schedule is moved based on even Manifold PM3/PM2 Pressure

The chart Below shows the PM3/(PM3 + PM2) split for a fixed PM1 split as a function of NOx emissions.

Allowable Adjustments of PM1 nozzle in Mode 6 nozzle from Nominal Splits listed in controls specification

This is solely dependant on Dynamics --- the optimum PM1 emissions will be about 13-14% PM1 split for a given PM3/PM2 split. DO NOT increase PM1 split past 16% without consultation.

This may cause the PM1 nozzle to attach and as mentioned in previous sections 100Hz dynamics may jump from 1-10 psi unexpectedly.

The chart below shows the PM1 Nozzle for a fixed PM3/PM2 split as a function of NOx

emissions:

Expected Combustion Parameters: Dynamics < 2.0 (130-150 Hz) / <1.0 (100-125Hz)TTXSP1< 60 F (usually 40 - 50 F)FD_intens_n >80 Counts NOX 4 - 10 ppmvd @15% O2 ppmvd

CO

1.0 ppmvd 7FA DLN

2.67

8910

1112131415

PM1 (%)

N O x @ 15% O 2 (p p m v d )

Expected NOx Emissions vs Load

LOAD REJECTION

A load rejection is a transient that takes the machine out of its normal operational window for a short duration of time, approximately 30 seconds. Having all commissioning aspects such as DLN tuning complete will help to prevent any

problems such as flameout or high exhaust temperature spreads during the event.All modes will be driven to the PM1+PM2 nozzle combination, then the PM2nozzles which are given an open loop fuel command for a specified amount of time will be cut off and all the fuel will be driven to the PM1 nozzle. The

DLN_MODE on the MARK V will read Mode 1 during the breaker open event even though fuel is being driven to the PM2 nozzles.

Please reference DLN2.6 commissioning procedure, it details required pass/fail criteria for a load rejection and combustor diagnostics in the event of an unsuccessful load rejection Appendix A

tuning spreadsheet:

Please include the following parameters in the spreadsheet

7FA DLN 2.6

051015202530354045505560657075800

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

105

% Gas Turbine Load

I S O N O x @ 15% p p m v d

危险废物焚烧NOx超低排放技术方案

危险废物焚烧NOx超低排放技术方案 摘要:针对危险废物焚烧项目单一采用SNCR脱硝工艺、NOx排放值难以满足超低排放标准的情况,提出采用"SNCR+低温SCR脱硝"和"SNCR+臭氧脱硝"两种工艺方案对现有的危废焚烧烟气处理系统进行NOx超低排放改造.通过技术经济分析,拟推荐将"SNCR+臭氧脱硝"工艺作为危废焚烧项目NOx超低排放改造的优先选择. 危险废物是指列入国家危险废物名录或者根据国家规定的危险废物鉴别标准和鉴别方法认定的具有腐蚀性、毒性、易燃性、反应性和感染性等一种或一种以上危险特性,以及不排除具有以上危险特性的固体废物。目前国内普遍采用焚烧法对危险废物进行处理,回转窑以其处理种类广、适应性强、焚烧较彻底等优点而成为焚烧法处理危险废物的主要炉型。 危险废物焚烧产生的烟气中含有较多的NOx,NOx 与SO2 是造成大气污染和产生酸雨的主要原因。随着国家环保要求的日趋严格,许多地方政府也逐渐提高了地方的环保要求。对于危险废物焚烧项目,已有地区出台了比GB 18484-2001《危险废物焚烧污染控制标准》更加严格的排放标准,例如山东省要求:在污染物重点控制区NOx≤100 mg/m3。此标准已经明显高于欧盟2010 当中对于NOx 排放的要求,这对于危险废物处理企业实现超低排放提出了巨大的挑战。目前,危废焚烧项目烟气处理大部分采用“SNCR+急冷塔+干法脱酸+活性炭+袋式除尘+湿法脱酸+

烟气加热”工艺。此工艺仅能够实现50%左右的NOx 脱除效率,脱除后的NOx 排放值在200~300mg/m3 之间,难以满足NOx 超低排放的要求。本文以年处理量为3 万t 的危险废物焚烧项目为例,提出采用“SNCR+低温SCR 脱硝”和“SNCR+臭氧脱硝”两种组合工艺进行提升改造,并进行技术和经济分析,以期找到一种最佳方案。 1 项目概况 目前,国内主流的危险废物焚烧项目处置规模为30 000 t/a,一般采用“回转窑+二燃室+余热锅炉(SNCR)+急冷塔+干法脱酸塔+活性炭+袋式除尘器+湿法脱酸塔+烟气加热”。在此工艺下,NOx 排放水平为:平均值250 mg/m3,峰值300 mg/m3(以NO2 计算),已不能满足山东等地区的排放要求(<100 mg/m3)。常规危废焚烧项目设计及运行数据见表1。 1.jpg 2 改进工艺方案介绍 目前,市场上主流的脱硝工艺包括SNCR、SCR、臭氧脱硝、烟气再循环、低氮燃烧等。鉴于危废项目烟气成分的复杂性及酸性气体成分较高,采用单一的脱硝工艺难以满足NOx 超低排放的要求,因此,需考虑采用组合工艺。结合目前危废项目主流工艺的特点,拟推荐采用“SNCR+低温SCR 脱硝”或“SNCR+臭氧脱硝”进行提标改造。下面对两种改造工艺进行介绍,并对比分析。

燃气轮机结构-燃烧室

第三章燃气轮机 3.1概述 (1)燃烧室功用及重要性 1.保证燃机在各种工况下,将燃料化学能转换为热能,加 热压气机压缩的空气,用于涡轮膨胀做功。 2.燃烧室是燃机的主要部件之一,燃机的性能、可靠性、寿命 皆与它有密切关系。 (2)燃烧室的工作条件 ①燃烧室在高温、大负荷下工作 ②燃烧室在变工况下工作 ③燃烧室在具有腐蚀性的环境下工作 ④燃烧室内的燃烧过程是一个极其复杂的物理化学过程 ⑤燃烧室中的燃烧在高速气流及贫油混合气情况下进行 (“空气分股”、“减速扩压”、“反向回流”) (3)燃烧室的设计要求 ①不同工况下,燃烧室工作应稳定 ②燃烧要安全 ③燃烧室具有最小的流体阻力 ④燃烧室出口温度场应能满足涡轮的要求 ⑤在任何使用条件下,燃烧室都应该迅速、可靠地启动点火,且联 焰性好 ⑥工作寿命长 ⑦燃烧室的尺寸和质量要小 ⑧排气污染应能满足国家标准要求 ⑨检视、装拆和维修应当方便 3.2三种基本类型燃烧室 的结构概述 (1)分管燃烧室 1.结构特点 管形火焰筒的外围包有一个单独的壳体,构成一个分管,沿燃气轮机周围6-16 个这样的分管,各分管用传焰管连通,以传播火焰和均衡压力。 2.优点: ①装拆、维修、检修方便 ②因各个分管的工质流量不大,调试容易,实验结果比较接近实际 情况 3.缺点: ①装拆、维修、检修方便 ②因各个分管的工质流量不大,调试容易,实验结果比较接近实际 情况

(2)环管燃烧室 1 .结构特点: 若干个火焰筒均匀排列安装在同一个壳体内,相邻火焰燃烧区 之间用传焰管连通。 2.优点: ①适合与轴流式压气机配合,布局紧凑、尺寸小、刚性小; ②气流转弯小,流体阻力小,热散失亦小; ③调试比较容易,加工制造的工作量比分管小。 3.缺点: ①燃烧室出口温度场沿周向不够均匀; ②燃烧室的流体损失较大; ③耗费的材料、工时较多; ④质量较重。

金属陶瓷

金 属 陶 瓷 材 料 2014级材料一班 王倩文 1430140512

目录 一、金属陶瓷的定义 (3) 二、金属陶瓷的特点 (4) 1.金属对陶瓷相的润湿性好。 (4) 2.金属相与陶瓷相应无剧烈的化学反应 (4) 3.金属相与陶瓷相的膨胀系数相差不会过大 (4) 三、金属陶瓷的行业现状 (5) 1.中国硬质合金工业产业分布、生产企业和研发机构 (5) 2.碳化钛基金属陶瓷 (5) 2.1 切削加工领域的应用 (6) 2.2 航天航空工业方面的应用 (6) 2.3 其他方面的应用 (7) 3.碳氮化钛基金属陶瓷 (8) 3.1 Ti(C,N)基金属陶瓷组分和成分设 (8) 3.2 晶粒细化 (9) 3.3 Ti(C,N)基金属陶瓷的应用 (9) 4.三元硼化物金属陶瓷 (10) 四、金属陶瓷的发展趋势 (11) 1.新材料的研究与开发。 (11) 2.超细晶粒和纳米级金属陶瓷。 (12) 3.梯度金属陶瓷的应用开发。 (12) 4.金属陶瓷回收再利用问题。 (12) 5.基础研究的发展。 (13)

材料是人类文明的里程碑,是人类赖以生存和得以发展的重要物质基础。正是材料的使用、发现和发明,才使人类在与自然界的斗争中,走出混沌蒙昧的时代,发展到科学技术高度发达的今天。当今世界,能源、信息、材料已成为人类现代文明进步的标志,继金属、有机高分子材料以后,金属陶瓷材料正以其卓越的性能、繁多的品种和广泛的用途进入各行各业,其发展之快,作用之大,令世人瞩目。金属陶瓷材料具有比强度高、比模量高、耐磨损、耐高温等优良性能,在众多场合已被作为新材料的代名词,成为现代高新技术、新兴产业和传统工业技术改造的物质基础,也是发展现代国防所不可缺少的重要部分,引起了世界各国尤其是发达国家的高度重视,纷纷投入巨资进行研究开发,把金属陶瓷材料作为本国高技术发展的一个重要领域。 一、金属陶瓷的定义 金属陶瓷是由陶瓷硬质相与金属或合金粘结相组成的结构材料。从金属陶瓷英文单词Cermets来,是由Ceramic(陶瓷)和Metal(金属)结合构成的。金属陶瓷既保持了陶瓷的高强度、高硬度、耐磨损、耐高温、抗氧化和化学稳定性等特性,又具有较好的金属韧性和可塑性。由于“金属陶瓷”和“硬质合金”两个学科术语没有明确的分界,所以具体材料也很难划分界线,从材料的组元看,“硬质合金”应该

超低排放方案

第一章总的部分 1、项目概况 本项目为电厂2×35 t/h+1×75 t/h锅炉超低排放项目,项目建成后,锅炉烟气中烟尘最终排放浓度<5 mg/Nm3,SO2最终排放浓度<35 mg/Nm3,NOx最终排放浓度<50 mg/Nm3,满足超低排放指标要求。2、编制依据 (1)《环境空气质量标准》(GB3095-2012)二级标准; (2)《山东省火电厂大气污染物排放标准》(DB37/664-2013); (3)山东省环保厅《关于加快推进燃煤机组(锅炉)超低排放的指导意见》(鲁环发[2015]98号); (4)国家有关法律、法规、方针及产业政策和投资政策; (5)建设单位提供的有关基础资料。 3、编制原则 (1)项目建设必须遵守国家各项政策、法规和法令,符合国家产业政策、投资方向及行业发展规划,贯彻相关的标准和规范。以满足环境保护和节能减排的社会效益为中心,兼顾投资成本和经济效益的合理性。 (2)严格按照建设项目的范围和内容要求进行编制,遵守基本建设程序。设计中注意节省投资,合理布置装置总图。在充分分析交通运输、原料供应、水源条件及电厂可依托设施等因素的基础上,充分利用电厂现有公用工程(水、电、汽)、已形成的交通运输等有利条件,合理选择装置总图布置,尽可能节省项目建设投资,最大限度地降低项目成本。 (3)采用的技术为国家产业政策积极推荐倡导的环保节能型、技术先进的工艺路线。在设计中按照“工艺技术成熟、装置可靠、经济运行合理”的基本原则,充分利用企业现有设施、少占用地、节约投资、合理利用资金。

(4)认真贯彻国家有关劳动安全、工业卫生和环境保护的法律法规,三废治理实现“三同时”,提高综合治理的水平;贯彻“安全第一、预防为主”的方针,保证项目投产后符合职业安全卫生的要求,保障劳动者在生产过程中的安全与健康。

燃煤电厂烟尘超低排放技术

燃煤电厂烟尘超低排放技术 前言 十二五期间,我国平均雾霾天数逐渐增多,空气污染加剧,霧霾严重影响人们身体健康和正常工作、生活秩序。而雾霾天气的形成与一次细颗物PM2.5的排放及环境空气中的二次细颗粒物的形成密切相关。我国的能源消费主要以煤炭为主,发电方式在很长的一段时间内是以燃煤发电为主。《火电厂大气污染排放标准》( GB 13223-2011) 要求在一般地区烟尘排放限值30 mg /m3,重点地区烟尘排放限值20 mg /m3。基于这样的原因,许多大型电厂都安排了电袋复合除尘器,基本上达到了排放要求。2014年9月12日,国家发改委、环境保护部、能源局联合印发《煤电节能减排升级与改造行动计划( 2014-2020)》的通知中,强调严控大气污染物排放,东部地区11个省市新建燃煤发电机组大气污染物排放浓度基本达到燃气轮机组排放限值,在基准含氧6%条件下,烟尘、SO2、NOx排放浓度分别不高于10、35、50 mg /m3,中部地区8 省则要求接近或达到燃气轮机组排放限值,鼓励西部地区接近或达到燃气轮机组排放限值。 1.成熟的除尘器技术 目前国内比较成熟且适用于各级容量机组的除尘技术主要是静电除尘器和袋式除尘器。 (1)静电除尘器使用周期长、维护费低且适用性较广泛,国内电除尘器出口烟尘浓度限制为20 mg /m3时,50%以上的煤种适用常规电除尘器; 但静电除尘器耗电量大,设备复杂、占地大并且对粉尘比电阻要求较高。对除尘效率低于99.8%,通常选用电除尘器。像神府东胜煤、晋北煤等电除尘器适应性较好的煤种,宜选用电除尘器。 (2)布袋式除尘器对粉尘气流量的变化适宜性强,具有除尘效率高,运行稳定,适用范围广,操作维护容易并且可处理高温、高比电阻的粉尘,但布袋除尘寿命主要取决于滤袋的使用寿命,不适宜于黏结性强及吸湿性强的粉尘,特别是烟气温度不能低于露点温度,否则会产生结露,致使滤袋堵塞。像准格尔煤、宣威煤、澳大利亚煤等电除尘器适应性差的煤种,不宜选用常规电除尘器,可选用布袋除尘器。 2.高效除尘技术方案 2.1湿式电除尘器 湿式电除尘器是直接将水雾喷向电极和电晕区,水雾在芒刺电极形成的强大的电晕场内荷电后分裂进一步雾化,在这里电场力、荷电水雾的碰撞拦截、吸附凝并,共同对粉尘粒子起捕集作用,最终粉尘粒子在电场力的驱动下到达集尘极而被捕集;与干式电除尘器通过振打将极板上的灰振落至灰斗不同的是:湿式电除尘器则是将水喷至集尘极上形成连续的水膜,采用水清灰,无振打装置,流动水膜将捕获的粉尘冲刷到灰斗中随水排出。湿式电除尘器对酸雾、有毒重金属以及PM10,尤其是PM2.5 的细微粉尘有良好的脱除效果。 2.2低低温静电除尘器技术

航空发动机燃烧室参数化建模

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