boiler losses

Information about boiler losses

Published on January 6, 2011

Author: shivajichoudhury

Source: authorstream.com

Content

BOILER LOSSES symptoms & causes: BOILER LOSSES symptoms & causes SHIVAJI CHOUDHURY BENEFIT -identification of losses: BENEFIT -identification of losses Efficiency increase Reduction in fuel cost Green house gases emission decrease Particulate emission reduction Availability improvement Reduction in O&M cost Less capacity addition Increase profitability BOILER LOSSES: BOILER LOSSES Symptoms Excess air or high O2 Boiler efficiency less than design Exit gas temp high causes 1.Moisture losses 2.Dry gas losses 3.Incomplete combustion 4.Radiation losses Boiler: Boiler SUPER CRITICAL BOILER 1.MOISTURE LOSSES: 1.MOISTURE LOSSES Coal quality Increase in coal surface moisture High moisture in air Tube leakage Excessive Soot blowing 1.1.Boiler Tube leakage: 1.1.Boiler Tube leakage symptoms Increased make up Increased precipitated current draw Increased stack opacity Boiler walk down Decreased stack temp 1.2.Change in Coal quality: 1.2.Change in Coal quality Increased H2 in coal Increased in internal moisture in coal. 1.3.Increase in coal surface moisture: 1.3.Increase in coal surface moisture Symptoms Decreased mill outlet temp Increased mill current draw Increased primary air temp Decreased stack gas temp 2.Dry gas losses: 2.Dry gas losses Dry gas losses are caused by high-excess air and high exit gas temperatures. High excess air means that greater quantity of air than is required for optimum combustion is being heated in the combustion process. This extra quantity reduces boiler efficiency by increasing the energy required to heat the air . 2.1.Dry gas losses: 2.1.Dry gas losses Symptoms Increased O2 Change in stack gas temp Causes 2.1.Boiler casing in leakage 2.2.Air pre heater leakage 2.3.Incorrect fuel to air ratio 2.4.Fouled heat transfer surfaces 2.2.BOILER CASING AIR IN LEAKAGE: 2.2.BOILER CASING AIR IN LEAKAGE Decreased exit furnace temperature (Before econ) Low combustion air flow and normal O2 at furnace exit Decreased exit boiler temperature (after econ ) 2.3.AIR PRE HEATER LEAKAGE: 2.3.AIR PRE HEATER LEAKAGE Decreased avg cold end temp Increased O2 across air heater and normal O2 at boiler exit. 2.4.INCORRECT FUEL TO AIR RATIO: 2.4.INCORRECT FUEL TO AIR RATIO High O2 at boiler exit Incorrect combustion control signals. 2.5.FOULED HEAT TRANSFER SURFACES: 2.5.FOULED HEAT TRANSFER SURFACES Boiler water walls Increased main steam temperature Super heater Decreased main steam temperature Re heater Decreased re heater temperature Economizer Decreased in economizer out temp Increased in main steam temp Air pre heater Low exit air temp Normal inlet gas and air temp Decreased in air pre heater DP (erosion) Increased in air pre heater DP (Plugged) 3.INCOMPLETE COMBUSTION: 3.INCOMPLETE COMBUSTION SYMPTOM Unburned carbon loss in ash Decreased O2 and increased in CO CAUSE Coal quality Increased carbon content Increased ash content Burner tips plugged/eroded Burner damper setting Improper aux to burner air ratio Incorrect fuel to air ratio Decrease in mill fineness 3.1.DECREASE IN MILL FINENESS: 3.1.DECREASE IN MILL FINENESS SYMPTOM Sieve test results: fineness < 70% thru 200 mesh. CAUSE Loss of roller tension Ring roller wear Classifier vane wear Exceeding mill capacity Classifier vane improperly adjusted 3.2.Unburned combustibles: 3.2.Unburned combustibles The unburned combustibles in the ash are related to the excess air level , the pulverizer settings , classifier settings , and burner operations. Increasing the fineness of the coal will decrease the unburned carbon in the ash and increase boiler efficiency . However, this may increase pulveriser power consumption, wear, and maintenance. MILL : MILL Optimization Envelope: Optimization Envelope 4.RADITION LOSSES: 4.RADITION LOSSES Insulation (ducts, pipes, turbine etc ). No insulation Insulation damaged Poor insulation Cladding missing/loose Boiler skin temp >27 deg C above ambient air temperature. Surface air velocity HI ( > 30 meter per minute over surface or as per design). PowerPoint Presentation: BOILER -500 MW Efficiency LOSSES IN BOILER –Design (IN PERCENT ) 500 MW THERMAL POWER PLANT( AS PER BS 2886) at 100% TMCR 500 MW: LOSSES IN BOILER –Design ( IN PERCENT ) 500 MW THERMAL POWER PLANT( AS PER BS 2886) at 100% TMCR 500 MW DRY GAS- 4.32 H2O IN FUEL 2.15 H2O FROM COMP OF H2 3.68 H2O IN AIR 0.11 UNBURN CARBON 1.50 RADIATION 0.12 UNACCOUNTED 0.76 TOTAL LOSSES 12.64 Losses in Thermal Power Plant: Losses in Thermal Power Plant Impact of parameter deviation on HEAT RATE (210 MW ,KWU Turbine )-operator controllable parameters.: Impact of parameter deviation on HEAT RATE (210 MW ,KWU Turbine )-operator controllable parameters. SN PARTICULAR UNIT DESIGN PARAMETERS INCREASE OF HEAT RATE DUE TO DEVIATION IN KCAL/KWH MULTIPLICATION FACTOR 1 PARTIAL LOADING MW 210 24.7 PER 20 MW 1.235 2 MS PRESS KG/CM2 150 25.5 PER 20 KG/CM2 1.275 3 MS TEMP AT HPT INLET DEG C 535 7.5 PER 10 DEG C 0.75 4 HRH TEMP AT IPT INLET DEG 535 6.6 PER PER 10 DEG C 0.66 5 CONDENSER VACUUM mmHg 660 23.4 PER 10 mm Hg 2.34 6 FEED WATER TEMP DEG C 241 16 PER 20 DEG C 0.8 7 RH ATTEMP FLOW T/HR 0 6.4 PER 10 T/HR 0.64 8 OXYGEN % IN FLUE GASES % 3 8 PER 1% 8

Related presentations


Other presentations created by shivajichoudhury

THERMAL POWER PLANT SAFETY
03. 06. 2008
0 views

THERMAL POWER PLANT SAFETY

MECHATRONICS- AN INTRODUCTION
07. 06. 2008
0 views

MECHATRONICS- AN INTRODUCTION

DISTRIBUTED CONTROL SYSTEM
24. 06. 2008
0 views

DISTRIBUTED CONTROL SYSTEM

STEAM TURBINE  LOSSES
28. 12. 2012
0 views

STEAM TURBINE LOSSES

ENVIRONMENT MANAGEMENT
24. 06. 2008
0 views

ENVIRONMENT MANAGEMENT

Boilersafety
08. 04. 2008
0 views

Boilersafety

Super critical boiler
21. 08. 2014
0 views

Super critical boiler

Lubricanting oil additives
30. 08. 2014
0 views

Lubricanting oil additives

Indian silk sarees
05. 09. 2014
0 views

Indian silk sarees

Wear debris analysis
23. 09. 2014
0 views

Wear debris analysis

wear mechanism
23. 09. 2014
0 views

wear mechanism

Mangalyaan
24. 09. 2014
0 views

Mangalyaan

Infrared thermography
15. 10. 2014
0 views

Infrared thermography

Valves
17. 10. 2014
0 views

Valves

Sukhoi su 35
05. 02. 2016
0 views

Sukhoi su 35