Desirable as run information system for energy efficiency of utility class boilers
1. DESIRABLE as run INFORMATION
SYSTEM NEEDS FOR ENERGY
EFFICIENCY of UTILITY CLASS
BOILERS :
2. For energy efficiency, a desirable as run information
system on key thermal power station parameters may
cover the following, to take care of reporting needs, as
well as, as a powerful tool for management plans for
energy cost optimization
3. Actual Gen. (MU)
P L F (%)
Av. Hrs for Generation
Availability Factor (%)
Av. GCV of Coal (kCal/kg)
APC (MU)
APC (%)
Oil rate incl. start up (ml/kWh)
Coal Rate (kg/kWh).
Heat rate (kCal/kWh)
4. PAT/ORT/ERC target (MU)
Av. Hrs for Generation
Availability Factor (%)
APC %
P L F (%)
Coal Consumption
Oil Consumption
As fired GCV of Coal (kCal/kg)
Oil rate incl. start up (ml/kWh)
Coal Rate (kg/kWh).
Heat rate (kcal/kWh)
Thermal Efficiency (%)by heat loss method.
5. Sl. No Performance Parameter Unit
1 Avg. Unit Load MW
2 % OF NCR %
3 Main Steam Flow TPH
4 Main Steam Pressure kg/cm2 (g)
5 Main Steam Temperature OC
6 Feed Water Temperature at FCV OC
7 GCV of Coal (as received basis) kCal/kg
8 Hot Reheat Steam Pressure Kg/cm2
9 Hot Reheat Steam Temperature OC
10 Cold Reheat Steam Pressure kg/cm2
11 Cold Reheat Steam Temperature OC
12 G C V OF COAL (as fired basis) kCal/kg
13 TOTAL AIR FLOW TPH
14 GC V OF CARBON kCal/kg
15 BOTTOM ASH QTY. kg/kg
16 COMB. IN BOTTOM ASH %
17 COMB. IN FLY ASH %
18 FLY ASH QTY. kg/kg
6. Sl. No Performance Parameter Unit
19 Flue gas analysis (APH Out)
19.1 CARBON DIOX!DE (CO2) %
19.2 CO %
19.3 OXYGEN (O2) %
19.4 TEMPERATURE Deg C
20 Ambient air parameters
20.1 DRY BULB TEMP Deg C
20.2 WET BULB TEMP Deg C
20.3 RELATIVE HUMIDITY %
20.4 MOISTURE LOAD kg/kg
21 Proximate analysis of Coal
21.1 FIXED. CARBON %
21.2 VOLATILE MATTER %
21.3 TOTAL MOISTURE %
21.4 ASH %
21.5 G C V OF COAL (as fired basis) kCal/kg
22 Ultimate analysis of Coal
22.1 CARBON (C) %
22.2 HYDROGEN (H) %
22.3 SULPHUR (S) %
22.4 TOTAL MOISTURE (H2O) %
19.3 OXYGEN (O2) %
19.4 TEMPERATURE Deg C
8. %O2 at APH inlet
%O2 at APH outlet
%O2 at ID fan inlet
Diff. pressure on gas side across APH (mmwc)
Flue gas temperature at APH inlet (OC)
Flue gas temperature at APH outlet (OC)
Secondary air temperature at APH outlet (OC)
% Differential O2 APH to ID fans inlet
9. BEFORE AND AFTER CRUSHER SIEVE ANALYSIS
BEFORE MILL SIEVE ANALYSIS
MILL OUTPUT ANALYSIS as run :
50 Mesh
100 Mesh
150 Mesh
200 Mesh
11. HP HEATERS as run parameters:
HP Heater Extraction pressure
HP Heater Extraction Temperature
HP Heater drip pressure
HP Heater drip Temperature
TTD and DCA
LP HEATERS as run parameters:
LP Heater Extraction pressure
LP Heater Extraction Temperature
LP Heater drip pressure
LP Heater drip Temperature
TTD and DCA
12. Condensate pressure at HP Heater inlet
Condensate temperature at HP Heater inlet
Condensate pressure at HP Heater outlet
Condensate temperature at HP Heater outlet
Condensate pressure at LP Heater inlet
Condensate temperature at LP Heater inlet
Condensate pressure at LP Heater outlet
Condensate temperature at LP Heater outlet
Cond. Vacuum
13. CONDENSATE EXTRACTION PUMPS as run
PARAMETERS (CEP):
CEP Suction side pressure
CEP Suction side temperature
CEP Discharge header pressure
CEP Discharge header temperature
DE AERATORS
De aerator pressure
De aerator feed water temperature
14. Sl.
DESCRIPTION UNITS Nomenclature
No.
1 Condenser Back Pressure (Vacuum) mbar absolute
2 CW Inlet Temp. (Left) °C t1L
3 CW Inlet Temp. (Right) °C t1R
4 CW Inlet Temp. (L/R-avg) °C ( t1 )
5 CW Outlet Temp. (Left) °C ( t2L )
6 CW Outlet temp. (Right) °C ( t2R )
CW Outlet Temp.
7 °C ( t2 )
(L/R-avg)
15. Sl.
DESCRIPTION UNITS Nomenclature
No.
8 CW Temp. rise (avg) °C ( t2 – t1 )
9 Saturation Temp °C (T)
10 Terminal Temperature Difference (TTD) °C (T – t2)
Saturation and inlet temperature
11 °C (T-t1)
difference
t 2 t1
12 Condenser Effectiveness Factor T t1
13 DP Across Condenser (L) mwc
14 DP Across Condenser (R) mwc
DP Across Condenser
15 mwc
(L/R-avg)
16 Condenser CW flow M3/hr
17 LMTD °C
18 Condenser Thermal Load MkCal/hr
16. AUXILIARIES POWER CONSUMPTION:
Overall Auxiliary Power Consumption
MU %
Total Generation: Year
Auxiliary Power Consumption 100
Unit Key Auxiliaries MU %
BFP's
CW Pumps
ID Fans
PA Fans
Coal Mills
CEP's
FD Fans
17. Unit Load (MW)
Frequency (Hz)
Suction flow (TPH)
BFP flow (TPH)
Suc. Pressure (kg/cm2)
Dis. Pressure (kg/cm2)
Total Dev Head (kg/cm2)
Total Dev Head (TDH) (mwc)
Suction Temp. (0C)
Density (kg/m3)
BFP (motor input) (kW)
Scoop position (%)
% Loading on motor
% Loading on flow
%Recirculation
% Loading on Head
Sp. Energy Consumption (kWh/T)
Efficiency %
FRS pressure drop
18. Unit Load (MW)
Frequency (Hz)
CEP flow (TPH)
Suc. Pressure (Cond. Back Pr.) (kg/cm2)
Dis. Pressure (kg/cm2)
Total Dev Head (kg/cm2)
Total Dev Head (TDH) (mwc)
Suction Temp. (0C)
Density (kg/m3)
CEP (motor input) (kW)
% Loading on motor
% Loading on flow
% Loading on Head
Sp. Energy Consumption (kWh/T)
Efficiency %
19. Unit Load (MW)
Frequency (Hz)
CW pump flow (TPH)
Suc. Pressure (mwc)
Dis. Pressure (kg/cm2)
Total Developed Head (kg/cm2)
Total Developed Head (TDH) (mwc)
CW pump (motor input) (kW)
% Loading on motor
% Loading on flow
% Loading on Head
Sp. Energy Consumption (kWh/T)
Efficiency %
CW Bypass valve condition
20. Unit load (MW)
Frequency (Hz)
FGT at ID inlet (0C)
Density (kg/m3)
Avg. Suction Press. (mmwc)
Avg. Discharge Press. (mmwc)
Total static head developed (mmwc)
FG Quantity handled (CMS)
kW of ID fan motors (kW)
Scoop position (%)
Or IGV open (%)
% Loading on motor
% Loading on flow
% Loading on Head
Sp. Energy Consumption (kWh/T)
Efficiency %
% Oxygen difference across APH inlet and ID fan inlet
21. Unit load (MW)
Frequency (Hz)
Suction temperature (0C)
Density (kg/m3)
Avg. Suction Press. (mwc)
Avg. Discharge Press. (mwc)
Total static head developed (mwc)
FD air flow (TPH)
kW of FD fan motors (kW)
IGV/Damper open (%)
% Loading on motor
% Loading on flow
% Loading on Head
Sp. Energy Consumption (kWh/T)
Efficiency %
22. Unit load (MW)
Frequency (Hz)
Secondary air temperature(deg C)
Mill outlet temperature (deg C)
Mill differential pressure (mmwc)
Coal flow (TPH)
Air flow (TPH)
Coal sieve analysis (mill inlet)
Coal fineness at mill outlet(passing on 200 mesh)
Motor input kW
% Loading on motor
% Load on coal output
Sp. Energy Consumption (kWh/T)
Mill rejects %
23. Unit load (MW)
Frequency (Hz)
Suction temperature (0C)
Density (kg/m3)
Avg. Suction Press. (mmwc)
Avg. Discharge Press. (mmwc)
Total static head developed (mmwc)
PA air flow (CMS)
kW of PA fan motors (kW)
% Loading on motor
% Loading on flow
% Loading on Head
Sp. Energy Consumption (kWh/T)
Efficiency %
24. COOLING TOWERS (CT):
Unit load (MW)
Frequency (Hz)
Hot well temperature (0C)
Cold well temperature (0C)
DBT & WBT at CT fan outlet
DBT & WBT at ambient.
CT fan flow (CMS)
Blade angle setting
CT effectiveness %
Cycles of concentration
CT approach
25. FAD test:
Initial pressure at receiver (kg/cm2)
Final pressure at receiver (kg/cm2)
Receiver + pipe volume (M3)
Time taken from initial pressure to final pressure (Min)
Compressor motor input power (kW)
Sp. Energy Consumption (kWh/M3)
Compressor efficiency
26. Plant running hrs
Coal Qty handled (TPH)
Direct Bunkering %
Stacking & Reclaiming %
% Capacity Utilization
Overall unit consumption (CHP)
Overall Sp. Energy Consumption (kWh/T)
ASH HANDLING PLANT (AHP):
Unit-wise ash generation(TPH)
Average Ash- Water Ratio
Overall unit consumption (AHP)
Sp. Energy Consumption (kWh/T of ash)
27. Make-up water consumption in each unit as %:
Blow down % in each unit:
Number of soot blowers installed and actually operational:
Number of LP heaters operational:
Number of HP heaters operational:
number of unit trippings due to boiler tube leakages and other
reasons:
Mill outage hours:
Oil gun hours:
28. 1. High Pressure Turbine Efficiency
A. Effect on Heat Rate (per percentage points):
•0.2 % of Unit Heat rate or 5 kcal/kWh for a unit with a HR
of 2500 kcal/kWh.
B. Possible Causes of Deviation
•Erosion of nozzle blocks
•Erosion of turbine blades
•Deposits of nozzles or blades
•Broken turbine blades
•N2 packing leak (HP and turbine are in the same shell)
•Excess gland packing leaks
•Strip Seal leakage
•Malfunctioning Control Valve
29. C. Possible Corrective Measures
•Repair or replace nozzle block
•Repair or replace turbine blades
•Clean turbine blades
•Replace gland packing
•Replace turbine seal strips
30. 2. Intermediate Pressure Turbine Efficiency
A. Effect on Heat Rate (per percentage point):
•0.2% of unit Heat rate or 5 kCal/kWh for a unit with a HR of 2500
kCal/kWh.
B. Possible Causes of Deviation
•Erosion turbine blades
•Deposits on turbine blades
•Reheater bypass valve leakage
•Excess Gland Seal leakage
•Strip seal leaks
C. Possible Corrections
•Repair or replace turbine blades
•Repair leaking reheater bypass valve
•Repair strip seal
•Repair gland seals
31. 3. Main Steam (Throttle) Pressure
A. Effect on Heat Rate (per kg/cm2)
•1 kCal/kWh
B. Possible Causes of Deviation
•Feed water flow too low (once-through units)
•Firing rate inadequate
C. Possible Corrections
1. Operator Controllable
•Increase feed water flow
•Increase firing rate
32. 4. Main Steam (Throttle) Temperature
A. Effects on Heat Rate (per deg C)
• 0.5 kCal/kWh
B. Possible Causes of Deviation
•Super heater spray control problems
•Super heater spray valve leakage
•Fouling of the super heater (low temperature)
•Fouling of the boiler water wall (high temperature)
•High excess air
•Burner tilts mispositioned
•Gas tempering flow inadequate
•Bypass dampers mispositioned
•Temperature control setting calibration drift
•Super heater tube leaks
•Incorrect amount of super heater heat transfer surface
33. C. Possible Corrections
•Blow soot
•Adjust burner tilts
•Adjust bypass damper settings
•Control excess air
•Manually control super heater spray flow
•Calibrate temperature control set point
•Repair super heater spray control valve
•Clean boiler water walls
•Clean super heater platens
•Repair super heater tube leaks
•Add or remove super heater heat transfer surface
34. 5. Reheat Temperature
A. Effect on Heat Rate (per deg C)
•0.5 kCal/kWh
B. Possible Causes of Deviation
•Reheat Attemperation control problems
•Reheat Attemperation control valve leakage
•Fouling of the reheater (low temperature)
•Fouling of the boiler water wall (high temperature)
•Fouling of the super heater
•High excess air
•Burner tilts mispositioned
•Gas tempering flow inadequate
•Bypass dampers mispositioned
•Reheater tube leaks
•Incorrect amount of reheater heat transfer surface
35. C. Possible Corrections
•Blow soot
•Adjust burner tilts
•Adjust bypass damper settings
•Adjust attemperating air flow damper
•Control excess air
•Manually control reheat spray flow
•Repair super heater spray control valve
•Clean boiler water walls
•Clean super heater platens
•Clean reheater platens
•Repair reheater tube leaks
•Add or remove reheater heat transfer surface
36. 6. Super heater Attemperation
A. Effect on heat rate (for 10 t/hr flow rate):
• 0.25 kcal/kWh
B. Possible Causes of Deviation
•Improperly adjusted control set point
•Leaking spray control valve
•Broken spray nozzle
•Fouling of boiler water walls
•High levels of excess air
•Improperly set gas attemperation
•Improperly set gas bypass dampers
37. C. Possible Corrections
•Blow water wall soot
•Reduce excess air to proper levels
•Adjust gas attemperation
•Adjust gas bypass dampers
•Repair spray valves
•Calibrate temperature controls
•Replace spray nozzle
38. 7. Reheat attemperation
1. Effect on heat rate (per 1% of MS flow):
•2.5 to 3.5 kCal/kWh
B. Possible causes of Deviation
•Fouled water walls
•High levels of excess air
•Fouled super heater sections
•Improperly set gas bypass dampers
•Improperly spray control valve
•Broken spray nozzle
C. Possible Corrections
•Adjust gas bypass dampers
•Adjust excess air to proper levels
•Soot blow water walls
•Soot blow super heater sections
•Repair spray control valves
•Replace spray nozzles
•Calibrate temperature control set point
39. 8. Condenser Backpressure
A. Effect on heat rate (per 1 mm Hg)
•2 kCal/kWh
B. Possible causes of Deviation
•Air leakages
•Excess condenser load
•Tube fouling
•Low circulating water flow
•Increases in circulating water inlet temperature
•Changes in ambient conditions
•Problems with cooling tower performance
C. Possible Corrections
•Increase circulating water flow
•Add an additional vacuum pump
•Check cycle isolation
•Place additional circulating water pumps in service
•Place additional cooling tower cells in service
40. 9. Auxiliary Power Consumption
A. Effect on Heat Rate (per percentage point):
• 20 kCal/kWh
B. Possible Causes of Deviation
•Continuous running of non continuous loads
•Decline in efficiency of operating equipment
•Operation of redundant equipment during low-load operation
C. Possible Corrections
•Stop non-continuous loads
•Reduce equipment operation at low loads
•Repair or replace inefficient equipment
•Maintain equipment whose power usage increases with deteriorating
performance, e.g., electrostatic precipitators, pulverizes, etc.
41. 10. Make up Water Consumption
A. Effect on heat rate (per percentage point):
•6 kcal/kWh
B. Possible Causes of Deviation
•Boiler tube leaks
•Excess deaerator venting to atmosphere
•Excess continuous blow down
•Excess steam lost through condenser venting
•Valve packing leaks
•Pump seal leaks
•Steam leaks to atmosphere
C. Possible Corrections
•Check deaerator vent orifices or valve settings
•Repair valve and pump packing and seals
•Repair boiler tube leaks
•Optimize continuous blow down
•Isolate cycle losses
42. 11 . Feed water Heater Performance
A. Effect on Heat Rate:
1. TTD (per deg C):
• 1.8 kCal/kWh
2. DCA (per deg C)
• 0.2 kCal/kWh
3 High Pressure Heaters Out of Service:
• First Heater: 23 kCal/kWh
• Second Heater: 17 kCal/kWh
• Third Heater: 17 kCal/kWh
4 Heater out of service 0.67 kCal/kWh for every 1DegC feed water heating lost
B. Possible Causes of Deviation:
•Changes in heater level
•Changes in extraction line pressure drop
•Reduced condensate flow through the heater
•Heater baffle leaks
•Failure to vent noncondensible gases
•Tube fouling
43. C. Possible Corrections
• Set feed water heater levels
•Optimize feed water heater levels
•Maintain heater vent valves and line orifices
•Repair baffle leaks
•Clean tube bundles
12. Startup
A. Effect on heat rate:
•1.85 kcal/kWh
B. Possible Causes of Deviation
•Forced outages
•Unscheduled outages
C. Possible Corrections
•Eliminate unscheduled outages through effective predictive and preventive
maintenance.
44. 13.OTHER GENERIC OPTIONS :
•Upkeep of cooling tower fills to be in order.
•Thermal insulation of boiler surfaces to be in order.
•Makeup water consumption to be controlled to less than 3%
•Differential oxygen between air preheater inlet and ID fan inlet to be limited to 3
%.
•TTD of feed heaters to be maintained around 3 deg C
•FRS pressure drop to be maintained as low as feasible.
•Recirculation of feed water to be avoided in BFP circuit.
•If part loading is necessitated often, option of variable frequency drives for key
auxiliary drives may be considered.
•Direct bunkering rather than stacking reclaiming route is desirable in CHP.
•Mill loading/capacity utilization to be close to rating.
•Mill inlet coal size to be ensured close to design value.
•CHP loading to be preferably above 50 %
•Ash water ratio to be maintained closer to design value.
•Water balance to be carried out often to optimize water consumption.-