High Pressure and efficient Boilers for High Pressure and efficient Boilers for Cogeneration applicationsCogeneration applications

• By

• B. Shukla

• MD and Chief Consultant,• WHITE POWERCON• #2082,1stmain 4th cross Judicial Layout,• GKVK Post • BANGALORE-560065

•

What is CO-GENERATION?• This is a combined / integrated System of production of Electrical power and useful heat by sequential use of energy from a common fuel source generally bagasse).

• To generate surplus power

For Best Utilization of resources

. To have Independency in power and steam

The Major advantage of Co- Gen The Major advantage of Co- Gen power is ;-power is ;-

• A-Most techno- commercial viable Projects with short pay back.• B-Cost of power production is very cheap compare to that of • purchase power.• C-Dependability and reliability with quality of power.• D-Quick return on investments.• E-Restore ecological imbalance.• F-Ability to use Bio-Mass and organic matters like wood, grass and agro wastes and also municipal wastes.• G-Availability of power between Nov. to May when Hydel power

availability less.• H-provides ecmomical and timeluy solution of Power problems.

CO-GENERATION in SUGAR MILLS

How Cogeneration Saves Energy

BOILER ALTERNATORTURBINE

TO

PROCESS

TO PROCESS

Fuel

Air

TO POWER SUPPLY

CONDENSER

TO COOLING TOWER

COGENERATION PLANT LAYOUT

Feed water

PRDS

• Better Power Quality• Improved Reliability and run ability• Lower Energy Costs• Reduction CO2 in the environment• Conserve Natural Resources• Support Grid Infrastructure

– Fewer T&D Constraints– Defer Costly Grid Upgrades– Price Stability

Benefits of cogeneration

Steps for conservationSteps for conservation1.Government of India enforced the 1.Government of India enforced the energy conservation act 2001 with effect energy conservation act 2001 with effect from 1.3.2002.from 1.3.2002.

2.The initial phase of 5 years would be 2.The initial phase of 5 years would be implementation of the act . implementation of the act .

3.The act provides mainly for efficient use 3.The act provides mainly for efficient use of energy and its conservation.of energy and its conservation.

4.Industry using 4.Industry using

Mandatory Requirement of ActMandatory Requirement of Act

• Those unit having connected load of 5000 KWh are called as ‘ Designated Energy Consumer’.

• As per the act it is mandatory for all designated Energy Consumers to get Energy Audit conducted by an Accredited Energy Auditor. And to designate or appoint an Energy Manager.

Energy Saving potential areas in sugar industries

1.Convertion from low Pressure to HP

Boilers

2.Steam Boilers (Reducing moisture percentage

in Bagasse)

3.Crushing section

4.Evaporator section

FEASIBILITY STUDY (TYPICAL STEPS)

Energy auditing

Technical Analysis

Inception

Implementation Planning

Financing

Operation and maintenance

CASE STUDIESCASE STUDIES

• A-IMPROVEMENT PROJECT By

• I-BY RETROFITTING

• II- -RENOVATION &TECHNOLOGICAL UPGRADATION

• B-INITIATING NEW PROJECTS

RETROFITTINGRETROFITTING

• Replacement of old 18/21Kgs/cm to HP >100bars boilers

• A-Provision of Better control system.• B-Efficiency improvement by Automation• C-Reduction of unaccountable losses by • providing dust extraction system• D-Reduction of Boiler & TG down time &• efficiency improvement by water & steam • quality control

Case StudiesCase Studies

• Introducing New HP Boiler without affecting Present Existing System

      2002-03 2001-02 2000-01 1999-00 1998-99 Max Min Diff

% Saving scope

SL NO. PARTICULARS   UOM Actual Actual Actual Actual Actual        

1 Cane Crushed   MT 729598 736838 646051 700916 736663        

2 No. of Crop Days     173 191 159 165 188        

3 Crushing Rate/22 hours   MT 4162.95 3951 4194.98 4385.11 4230.29        

4 Crushing Rate/24 hours   MT 4541.39 4311.12 4576.34 4783.32 4614.77        

5 Crop Day Average   MT 4217.33 3857 4063.22 4247.98 3918.42        

6 Recovery   % 9.51 9.11 9.758 9.23 8.187        

7 Bagasse Moisture   % 50.66 50.56 50.11 50.4 51.3 51.3 50.11 1.19 2.32

8 Steam % Cane   % 48.76 50.71 48.75 49.45 49.74        

9 Power / Ton of Cane   KWH 24.68 25.46 25.18     25.8 24.68 1.08 4.19

  DOWN TIME ANALYSIS                    

Rs 51.57 lakhs per season

10 No Cane   Hrs-Mts 6.-00 57-50 142-15 154-55 204-10        

11 Mechanical   Hrs-Mts 64-35 59-30 4.-30 24-55 180-45 181 4.5 176 97.5

12 Electrical   Hrs-Mts 11.-10 53-55 4.-00 24-25 70-00 70 4 66 94.3

13 General Cleaning   Hrs-Mts 97-10 97-15 109-25 110-25 51-05 110 51.08 59.3 53.7

14 Lost % on Available Hours % 7.06 10.3 11.23 8.96 11.9 11.9 7.06 4.84 40.7

Comparison of performance during various seasns from 1998 to 2002

SL NO

PARTICULAR   UOM 2002-03 2000-01 1994-95 Max Min %saving scope

                   

  Plant Sanctioned Capacity MT 5000 5000 2500      

                   

1 Cane Crushed MT 729598 646051.4 721475.5      

2 No. of Crop Days   173 159 258      

3 Crushing Rate / 22 hours MT 4162.9 4149.982 2819.806      

4 Crushing Rate / 24 hours MT 4541.4 4576.344 3076.152      

5 Crop Day Average MT 4217.3 4063.216 2796.416      

6 Recovery   % 9.51 9.758 9.357      

7 Pol in Cane % 11.5 11.618 10.963      

8 Total Losses % 2 1.871 1.617      

  a)Bagasse % 0.55 0.541 0.54      

  b)Filter Cake % 0.08 0.07 0.05      

  c)Final Molasses % 1.27 1.211 0.99      

  d)Unknown Loss % 0.1 0.049 0.037      

9 Molasses % Cane % 4.52 4.449 4.415      

10 Bagasse % Cane % 29.56 30.32 31.22      

11 Cane Preparatory Index % 78.18          

12 Bagasse Moisture % 50.66 50.11 50.52      

13 Pol % Bagasse % 1.86 1.78 1.73      

14 Sugar quality ICUMSA % 90to130 80-120        

15 Total Available Hours HRS 4148-39 3816-33 6173-40      

Coomparison of performance with best two seasons

16 Down Time Hours HRS 292-55 428-25 544-45      

17 Imbibition% Fiber % 259.14 293.58 295.62      

18 Milling Loss   4.12 3.78 3.69      

19 Reduced Mill Extraction % 95.73 96.02 95.89      

20 Reduced B.House Extraction % 91.27 91.66 93.43      

21 Steam % Cane % 48.76 48.75 47.41 48.76 47.41 2.77

22 Power / Ton of Cane KWH 24.68 25.18      

Rs 21.62 lakhs/season

23 Peak Period Recovery % 9.68 9.923 9.83      

  DOWN TIME ANALYSIS                

24 No Cane   HRS 6.-00 142-15 54-15      

25 Mechanical   HRS 64-35 4.-30 152-15 64.58 4.5 93

26 Electrical   HRS 11.-10 4.-00 5.-30      

27 General Cleaning   HRS 97-10 109-25 164-00 109.416 97.16 11.2

28 Others   HRS 112-10 167-50 168-45 167.83 112.166 33.17

29 Lost % on Avaible Hours   % 7.06 11.23 8.82      

30 Process Stock-Brown Sugar   Qtls 2325 1477.49 694.65      

              341.8 213.8  128 hours

  Remarks:Possible saving of running hours =128 hours

  Possible increased in crushing of cane per season= 24220 MT/season  

ANALYSIS OF PERFORMANCE FOR THE SEASON 2002-2003(MONTH WISE)

SL NO PARTICULARS   UOM DEC.02 JAN.03 FEB.03 MAR.03 APL.03 MAY.03 JUNE.03 TOTAL Max Min

%saving

                             

1 Cane Crushed MT 48558.3 128742 134980 140288 127097 128072.4 21860 729598      

2 Recovery   % 8.05 8.84 10.06 10.66 10.14 8.75 6.68 9.61      

3 Sugar Production Qtls 3100 113875 13227.5 14747 13123.3 114975 25397 696220      

4 Season Days-Crop Day Days 14 31 28 31 30 31 8 173      

5 Season Days-Crushing Day Days 14 27 27 31 29 31 8 167      

6 Total Available Hours HRs 332-36 744-00 672-00 744-00 720-00 744-00 192-03 4148-39      

7 Total Working Hours HRs 330-51 641-40 636-35 705-45 676-15 692-10 172-28 3855-44      

8 Stoppage Hours HRs 1.-45 102-20 35-25 38-15 43-45 51-50 19-35 292-55      

  a)Want of Cane HRs 0-00 6.-00 0-00 0-00 0-00 0-00 0-00 6.-00      

  b)Engineering(Mech&Elec) HRs 0-00 5.-00 5.-55 20-45 12.-40 21-35 10.-20 75-45      

 c)Process   HRs 0-00 0-50 0-00 0-30 0-00 0-00 0-00 1.-20      

  d)General Cleaning HRs 0-00 41-40 26-15 0-00 29-15 0-00 0-00 97-10      

  e)Others   HRs 1.-45 48-50 3.-15 17-00 1.-50 30.15 9.-15 112-10      

9 Down Time % Available % 0.53 13.75 5.27 5.14 6.08 6.97 10.-20 7.06      

10 Crushing Rate / 22 hours MTs 3228.9 4414 4664.88 4373.12 4134.77 4617.712 2504.2 4162.95      

11 Crushing Rate / 24 hours MTs 3522.43 4815.3 5088.96 4771 4510.66 5037.504 2731.8 4541.39      

12 Crop Day Average MTs 3468.45 4153 4820.73 4525.41 4236.57 4131.368 2732.5 4217.33      

13 Crushing Day Average MTs 3468.45 4768.2 4999.27 4525.41 4382.66 4131.368 2732.5 4368.85      

14 Pol % Cane % 9.844 10.656 11.947 12.627 12.14 11.025 9.11 11.5      

15 Total Losses % 1.8 1.828 1.898 1.993 2.01 2.284 2.443 2      

  a)Final Molasses % 1.13 1.143 1.218 1.306 1.31 1.369 1.45 1.27      

  b)Bagasse % 0.521 0.543 0.54 0.545 0.56 0.57 0.6 0.55      

  c)Filter Cake % 0.08 0.081 0.083 0.084 0.08 0.087 0.105 0.08      

  d)Unknown % 0.069 0.062 0.057 0.058 0.06 0.263 0.288 0.1      

16 Reduced Mill Extraction % 94.79 95.31 95.88 96.12 96.02 95.64 94.48 95.73      

17 Reduced BH. Extraction % 91.66 91.49 91.39 91.15 91.19 91.14 90.46 91.27      

18 Pol % Bagasse % 1.89 1.88 1.86 1.85 1.84 1.84 1.9 1.86      

19 Bagasse % Cane % 27.53 28.82 29.06 29.42 30.19 30.75 31.63 29.56      

20 Final Molasses Purity % 29.6 30.45 30.99 31.71 31.51 31.55 34.15 31.35      

21 Molasses % Cane % 4.26 4.17 4.37 4.61 4.66 4.85 4.93 4.52      

22 Steam % Cane % 49.47 47.69 47.62 48.37 47.96 48.18 70.91 48.76      

23 Power per Ton of Cane Units 23.61 23.61 23.27 24.69 25.13 25.57 34.3 24.63 34.3 23.27 32.2

Remarks: Saving of power in terms of money will be Rs 77.15 lakhs /month. @Rs 5.00/KWH

% Recovery during 2002-03

8.05 8.84 10.06 10.65 10.148.75

6.68

0

2

4

6

8

10

12

Dec Jan Feb Mar Apl May Jun

Rec

ove

ry

%bagasse moisture

27.53 28.82 29.06 29.42 30.19 30.75 31.63

05

1015

20253035

Dec Jan Feb Mar Apl May Jun

Dec Jan Feb Mar Apl May Jun

%b

ag

as

se

mo

istu

re

Column 7

29

28.6

28.2

27.8

27.4

power consumption per ton of cane crushed

23.61 23.61 23.27 24.69 25.13 25.5734.3

0

5

10

15

20

25

30

35

40

Dec Jan Feb Mar Apl May Junpo

we

r c

on

su

me

d p

er

ton

of

ca

ne

BY Technological Up gradationBY Technological Up gradation

• A-Replacement of old low pressure Boilers to High pressure to get the benefits

improved cycle efficiency.

• B-Providing Topping up TG Set to optimize expenses on Electrical system.

• C-Better environments by Providing

• Emission monitoring.

Acquire Best Available Technology in Acquire Best Available Technology in New ProjectsNew Projects

• A-Select Most modern and reliable

• equipments

• B-Design Tailor make System.

• C-Select Flexible System for Better

utilization of resources and Better economy.

KCP Boiler70 TPH, 43.4ata &

400ºC

TBW Boiler70 TPH, 67ata & 485ºC

9.7

4

MW

, 7

0 tp

h

TG

ComparisonComparisonPrevailing SystemPrevailing System Proposed SystemProposed System

Multi fuel Boiler105ata, 525º C, 88%

Toppin

g

up T

G

set18

.6

MW

, 6

1 tp

h

TG

GEC TurbineSIEMENS Turbine

C

C

11 KV BUS

9.7

4

MW

, 7

0 tp

h

TG

18

.6

MW

, 6

1 tp

h

TG

C C

GEC Turbine SIEMENS Turbine

67

ata

& 4

85

ºC

42

ata

& 4

00

ºC

Actual Thermal Efficiency of existing power Actual Thermal Efficiency of existing power plant on dateplant on date

Heat value of KPC boiler ≈ 767 Kcal/kg (from steam table)(at 43.4 ata and 400ºC)

Then net heat value of KPC boiler ≈ 767 – 105 ≈ 662 Kcal/kg.

Thermal efficiency of KPC boiler = ηth = (Net heat value * Total Steam generation) / (CV of the bagasse * total bagasse consumption) ηth = (662 * 122759) / (2277 * 61672)

= 57.99% ≈ 58% ( against 69% of design)

Heat value of TBW boiler = 807.7 Kcal/kg (From steam table)(at 67 ata and 485ºC)Then net heat value of TBW boiler ≈ 807.7 – 105 ≈ 702.7 Kcal/kg

GCV of coal = (CV of coal * total coal consumption) / Total fuel consumption = (5500 * 4622) / 56213 = 452.22 Kcal/kgGCV of Bagasse = (CV of bagasse * total bagasse consumption) / Total fuel consumption = (2277 * 51591) / 56213 = 2089.77 Kcal/kg

Then net GCV = 452.22 + 2089.77 = 2542 Kcal/kg

Then net heat gain = heat gain * steam required for cane * efficiency of Topping TG set = 13.8 * 125*103 * 0.9 = 1552.5 Kcal/kg

Total power generation = 1552.5/860 = 1.8 MW

Transfer rate = 1800 * 24 * 330 * 1.96 = 2.79 crore.

Thermal efficiency of TBW boiler = ηth = (Net heat value * Total Steam generation) / (Net GCV * total fuel consumption) = (702.7 * 129399) * 100 / (2542 * 56213) η th = 63% (against 71.75% of design)

Average thermal efficiency of KPC & TBW boiler = (58+63) / 2 = 60.5%

Expected direct efficiency of multifuel boiler = 84%Then fuel saving = 84 – 60.5 = 23.5%

Cost of fuel saving = Actual cane crushed * % of fuel caned * % fuel savefor 02-03 = 729598 * 0.3 * 0.235 = Rs. 51436.65

Then total saving of bagasse = 51437 * 500 = Rs. 2,57,815 = 2.57 crore

Net gain in power = 2.79 croreNet gain in fuel save = 2.57 crore

Then total gain = 2.79+2.57 = 5.36 crore

Heat value of AFBC boiler = 821.5 Kcal/kg (from steam table)(at 515º C and 105 kg/cm2)

Then net heat gain = 821.5 – 807.7 = 13.8 Kcal/kg

From dataBudgeted crane crushed/year = 775000 M.TActual crane crushed/year = 72598.401 M.TNo. of crop days = 170 days% Steam required for crane = 48%% of bagasse in cane = 30%

Then steam required for cane/hr. = (budgeted cane crushed * %steam reqd. for cane) / (No. of days * 24) = (775000 * 0.48) / (170*24) = 91.176 tph ≈ 100 tphFor maximum efficiencysteam required for cane/hr = 100/0.80 = 125 tph

The Major advantage of Co- Gen The Major advantage of Co- Gen power is ;-power is ;-

• A-Most techno- commercial viable Projects with short pay back.• B-Cost of power production is very cheap compare to that of purchase

power.• C-Dependability and reliability with quality of power.• D-Quick return on investments.• E-Restore ecological imbalance.• F-Ability to use Bio-Mass and organic matters like wood, grass and agro

and • municipal wastes.• G-Availability of power between Nov. to May when Hydel power

availability • less.•

Continue---• H-provides ecmomical and timeluy solution of Power problems.

STEPS FOOR SAVINGSSTEPS FOOR SAVINGS

• !-Saving of Bagasse by adopting high technology HP Boilers• 2-Reduction of moisture in bagasse 50 to 45% by improving Milling

Technique.• 3-Reduction in Process steam consumptions in evaporator and Prime

movers • BLTFF evaporators • 4- Reduction in live s team consumption by using multi stage reaction

Turbines.• 5- Reduction in over consumptions of power TCH using new technique of • • Variable drives and high efficient auxiliaries. • 6-improve crushing rate by having quality power