Cogeneration Mentor Poveda Energy Efficiency Coordinator
COGENERATION Definition: Efficient production of two forms of useful energy from the same fuel resource, using the exhaust energy from one production system as the input to the other.
Characteristics Needs more physical space Additional investments Total system efficiency approach 70% Standard industrial boiler: 30-35% efficiency
Bottoming system Process equipment Lowpressure steam Turbine Generator Electricity High-pressure steam To preheat water Air Fuel Exhaust Exhaust Topping system Water Steam Water Turbine Generator Electricity Steam to process Fuel Air
Electric Generation Standard cycle Exhaust gases Steam (H.E.) 200 kwh 1/2 Barrel Fuel Combustion Chemical - Thermal Energy Water Boiler Thermal - Kinetic Energy Condenser Turbine Steam (L.E.) Electric Generator Mechanical - Electrical E. Electricity Electric Energy Fuel Energy Combustion Boiler Condenser Turbine Generator
Cogeneration Heat recovery boiler Exhaust gases Steam (H.E.) 200 kwh 1/2 Barrel Fuel Combustion Main Boiler Turbine Vapor (B.E.) Electric Generator Electricity 1000 kg steam Condenser Industrial Process Process Steam Electric Energy Fuel Energy Combustion Boiler Condenser Turbine Generator
COGENERATION PLYWOOD - ECUADOR
BEFORE COGENERATION ALL POWER FROM PUBLIC GRID PLYWOOD INDUSTRY INDUSTRIAL PROCESS WOOD WASTE GENERATION WOOD WASTE OPEN FIRE TO THE ENVIRONMENT: FUME PARTICLES CO, CO2 HOT GASES > 300º C THERE IS NOT RATIONAL USE OF ENERGY EXPENSIVE PRODUCTION FINES BUNKER BUYED TO STEAM PRODUCTION STEAM DEFICIT
CONDITIONS BEFORE COGENERATION Monthly plywood production = 2,000 m 3 Fuel oil to feed the boiler: Yearly expenditure: US$ 110,000 Annual electricity consumption (From local utility) =5,260,000 kwh/year. Annual fuel oil consumption: 300,000 gal: 11,500,000 kwh equiv Energy Index: energy consumption / Plywood production = 219+479=698 kwh/ m 3. Annual waste production transportation = US$ 25,000 All the waste were burned in open fire with high CO and particles production. Environmental pollution and fines from the local authority. To burn the residues was necessary an exclusive purpose team.
Cogeneration Project Comprehensive Project 1,000 kw Generator Steam generation improvement Insulation increase in steam distribution lines No more use of fuel oil
ELECTRIC SINGLE LINE DIAGRAM)
Demanda ( kw) Lun 00:00 07:00 14:00 21:00 04:00 11:00 18:00 01:00 08:00 15:00 22:00 05:00 Demanda ( kw) kwh Bus General =160,787.42 kwh Turbogen. =135,065.23 DEMANDA ENERGIA TURBOGENERADOR + EEQ kwh EEQ-Endesa = 28,263.25 Semana del 15 al 21 Enero/01 Vs. DEMANDA TOTAL (PERIODO SEMANAL) kwh Endesa-EEQ. = - 2,541.06 1400,0 Demanda máxima Bus General =1,270 kw 07h00 (Jueves 18) 1300,0 Demanda máxima Turbogenerador =1,220 kw 05h15 (Sabado 20) 1200,0 1100,0 1000,0 900,0 800,0 700,0 600,0 500,0 400,0 300,0 200,0 100,0 0,0-100,0-200,0 Lun 00:00 07:00 Demanda mínima Bus General =110.0 kw 02h45(Lunes 15) Demanda mínima Turbogenerador = 37.6 kw 20h15(Miercoles 17) Demanda máxima E.E.Q. =1,180 kw 20h00 (Martes 16) 14:00 21:00 04:00 11:00 18:00 01:00 08:00 15:00 22:00 05:00 12:00 19:00 Días de la Semana kw Bus Gen. kw TURBOGENERADOR. kw EEQ. 12:00 02:00 09:00 16:00 23:00 06:00 13:00 20:00 03:00 10:00 17:00 19:00 02:00 09:00 16:00 23:00 06:00 13:00 20:00 03:00 10:00 17:00 kwh Bus General =160,787.42 kwh Turbogen. =135,065.23 kwh EEQ-Endesa = 28,263.25 kwh Endesa-EEQ. = - 2,541.06 1400,0 1300,0 1200,0 1100,0 1000,0 900,0 800,0 700,0 600,0 500,0 400,0 300,0 200,0 100,0 0,0-100,0-200,0 TYPICAL LOAD PROFILE DEMANDA ENERGIA TURBOGENERADOR + EEQ Vs. DEMANDA TOTAL (PERIODO SEMANAL) Semana del 15 al 21 Enero/01 Demanda máxima Bus General =1,270 kw 07h00 (Jueves 18) Demanda mínima Bus General =110.0 kw 02h45(Lunes 15) Demanda máxima Turbogenerador =1,220 kw 05h15 (Sabado 20) Demanda mínima Turbogenerador = 37.6 kw 20h15(Miercoles 17) Demanda máxima E.E.Q. =1,180 kw 20h00 (Martes 16) Días de la Semana kw Bus Gen. kw TURBOGENERADOR. kw EEQ.
FINANCIAL CONDITIONS Project Cost =US$ 2,600,000 Financing: 50% Owner and 50% 5 year bank loan, 11% interest rate. US$ 1,300,000 at 11% in 5 years: US$ 12,000 each month Production: 675,000 kwh per month Generation Cost per kwh: 0.06 US$/kWh (62% capital and 38% operation) Cost per kwh from utility (1994) = US$ 0.10 Amount recovery per month: US$ 27,000 Repayment Time: 43 month (3.7 years) Without taking into account the savings in fuel oil
OPERATION CONDITIONS AFTER COGENERATION Annual plywood production = 42,000 m 3. Energy Index: energy consumption / Plywood production = 215 kwh/ m 3. Monthly consumption = 752,500 kwh. Internal Generation = 675,000 kwh / month. Difference to buy from utility =77,500 kwh/month ADVANTAGES Energy Efficiency lower the index kwh/ m 3. Reduction 3.98 kwh/ m 3. Savings in fuel oil = 110,000 US$ /year. Since the total production increases the residues increase. The annual cost to transport them most be = US$ 84,637 The pollution was reduced substantially and the fines were avoided.
ENERGY PRODUCTION AND CONSUMPTION COMPARISON BEFORE AFTER Annual plywood production 24,000 m 3 42,000m 3 Monthly plywood production 2,000 m 3 3,500 m 3 kwh vs. Production Index 219 kwh/ m 3 215 kwh/m 3 Annual energy consumption 5,2 mill. kwh 8,1 mill. kwh Energy monthly internal production 438 MWh 810 MWh Power self generation Difference to buy from Utility 675 kwh/month 135 kwh/month
Benefits Green Seal for export Pollution reduction No fuel oil to feed the boiler Less electricity from utility No fines from the local authority No more residues transportation