LOW GRADE WHU POTENTIAL- TEXTILE SECTOR

12-Aug-14R Rajmohan

Partnership to Advance Clean Energy-Deployment (PACE-D)(PACE-D)Technical Assistance Program

CONTENTS

• Process Flow • Sources of Low Grade Waste Heat • Overall Potential• WHU Solutions • Case Studies

Textile Processing : Illustrative for Cotton Prints

Source: Cluster Manual Pali Textile Cluster; BEE

Boiler

Thermopac

Process Utilities

Air compressors

Textile Processing : Pali Textile cluster- Quick overview

Source: Cluster Manual Pali Textile Cluster; BEE

Sl No Item Target Efficiency

1 Sources of Energy Electricity from Grid & Pet Coke

2 Energy Use pattern – Pet Coke

5 to 7 TPD (Power process)1 to 1.5 TPD (Small Units)

3 Energy Use pattern- Electricity

Power Process: 3000 kWh/DayOnly printing: 160-500 kWh/Day

4 Specific energy consumption ( Processing of polyester & Printing)

Electricity: 1.2 kWh/KgThermal: 15000 Kcals/Kg

Sources of Waste Heat

DryingDrying StenterStenter

DyeingDyeingJiggerJigger DryingDryingJiggerJiggerSingeingSingeing

Stretching

Stretching

BoilerBoiler

Low Grade WH: Overall PotentialEffluents

Quantity: 3000 Kg/CycleTemperature: 70 Deg C

WHR potential: 120000 Kcals/Cycle

Jiggering & Swing SteamReject condensate: 120 Kg/Hr

Temperature: 70 Deg CWHR potential: 6300 Kcals/Cycle

Drying & Jiggering SteamReject Effluent: 200 Kg/Hr

Temperature: 70 Deg CWHR potential: 12000 Kcals/Cycle

Drying & Jiggering waterReject condensate: 3500 Kg/Hr

Temperature: 70 Deg CWHR potential: 210000 Kcals/Cycle

Dyeing @ 140 Deg C

Reject effluent: 5000 Kg/Hr

Temperature: 100 Deg C

WHR potential: 408000

Kcals/Cycle

Stretching @ 120 Deg C

Reject Effluent: 123 Kg/Hr

Temperature: 100 Deg C

WHR potential: 1230 Kcals/Cycle

WHU- Overall potential0.323 Kg of Fuel/Kg of Cloth

Annual fuel savings: 93 MT/YearCost savings: 11.2 Lac Rs/Year

Mill producing 37 Kg of cloth/Hr

Low Grade WHU Technologies: Waste heat recovery from Boiler Flue gases - Economizer

• Waste heat recovery device • Usually used in boilers to recover waste heat from flue gases.• Recovered heat is used to pre-heat feed water to boiler• Useful where water feeding to boiler is continuous

BoilerFlue Gas

ECO

To Chimney

Feed water Pump

200 Deg.C

T1= 30 Deg.C

150 Deg.C

T2 = 50 Deg.C

Low Grade WHU Technologies: Waste heat recovery from Boiler/Thermopac Flue gases – Air Preheater

Boiler/ Thermo pac

Flue GasAPH

FD Fan

200 Deg.C

T1= 30 Deg.C

150 Deg.C

T2 = 80 Deg.C

Combustion air

• Waste heat recovery device • Usually used in boilers/Furnaces to recover waste heat from flue gases.• Recovered heat is used to pre-heat combustion air to boiler/Furnace• Useful where Economizer exists already

Low Grade WHU Technologies: Waste heat recovery from Boiler Flue gases – Water Preheater (S&T heat exchanger)

• Waste heat recovery device • Usually used in boilers to recover waste heat from flue gases.• Recovered heat is used to pre-heat boiler feed water• Useful when the feed water flow to the boiler is not continuous

Boiler

Flue Gas S& T

H E To Chimney

Water Pump

Feed Water Tank

Feed water Pump

Low Grade WHU Technologies: Waste heat recovery from Boiler Flue gases – Water Preheater- Heat pipe heat exchanger

• Waste heat recovery device • Usually used in boilers to recover waste heat from flue gases.• Recovered heat is used to pre-heat feed water to boiler• Useful to recover heat where Delta T is lower

Low Grade WHU Technologies: WHR from Boiler Blow Down – Flash Steam Recovery & Heat recovery from BD condensate

• Flash steam recovery from Boiler blow down • Heat recovery from the condensate of the blow down• Recovered heat is used to pre-heat Boiler feed water/ other hot water

requirements

Low Grade WHU Technologies: Condensate Recovery

• Condensate recovery device • No mechanical pumping• Recovered condensate is used as boiler feed water• Savings of both water and heat

Low Grade WHU Technologies: Heat Recovery from Hot effluents

• Waste heat recovery device • Used to recover heat from process effluents

Low Grade WHU Technologies: Heat Recovery from Hot Vapours

• Hot vapors from sources like Stenters are the heat source• Used to either generate hot water or to heat the fresh air to the source

equipments

CASE STUDY 1 : Waste heat recovery system in Boiler

Item Unit ValueAs Is To be

Flue gas temperature Deg C 204 180GCV of fuel Kcals/Kg 8000 8000Fuel used MT/Year 1260 1210Savings in fuel MT/Year 50Cost of Fuel Rs/MT 12000 12000Savings n Energy cost Rs/Year 600000Investment Rs 300000Simple Payback period Year 0.5

Savings by Installing Waste heat recovery System in Boiler

CASE STUDY 2 : Waste heat recovery system in Thermopac

Item Unit ValueAs Is To be

Flue gas temperature Deg C 250 180GCV of fuel Kcals/Kg 8000 8000Fuel used MT/Year 1800 1710Savings in fuel MT/Year 90Cost of Fuel Rs/MT 12000 12000Savings n Energy cost Rs/Year 1080000Investment Rs 500000Simple Payback period Year 0.5

Savings by Installing Waste heat recovery System in Thermopac

CASE STUDY 3 : Waste heat recovery –Boiler Blowdown

Item Unit ValueAs Is To be

Quantity of water per blowdownLit 200 200No of blowdown per day Nos 5 5Total blowdown quantity Lit/Day 1000 1000Total heat recovery from blowdownKcals/Day 80000 80000Savings in fuel MT/Yr 3.4Savings n Energy cost Rs/Year 40800Investment Rs 50000Simple Payback period Year 1.2

Savings from Boiler blowdown heat recovery

CASE STUDY 4 : Waste heat recovery- Jet Dyeing Machine

Item Unit ValueAs Is To be

No of Jet Dyeing Machine Nos 3 3Steam consumption/Hr Kg/Hr 150 150Flash steam recovery potentialKcals/Hr 28800Savings in fuel MT/Yr 29.5Savings n Energy cost Rs/Year 354000Investment Rs 200000Simple Payback period Year 0.6

Savings from Heat recovery- Jet Dyeing Machine

CASE STUDY 5 : PHE – Heat Recovery from Jet Dyeing Machine (Sameer Synthetics)

Temp. of water drained : 85oCProposal : Collect hot water and use for pre-heating cold water stream used for process

CASE STUDY 2: Cost Benefit Analysis

Number of Machines in Operation 9

Quantity of Water Drained/Batch/Machine 400 l

Number of batches/day/machine 10

Water temperature at outlet of machine 80oC

Expected temperature of effluent at outlet of PHE 38oC

Expected energy savings 1,512,000 kCal/day

Equivalent Fuel Savings 189 kg/day

Equivalent Cost Savings 6.8Lakh Rs/year

Investment 4 Lakh Rs

Simple Payback Period 7 Months