part 1: overview of cogeneration and its status in asia - Fire

Sample case study in a pulp and paper mill 109
• Power Generation (for thermal matching)
P =
PHR x S xHR CF
o
10
Where, P = electricity generation, MWh/year
6
PHR = power to steam ratio, kW/(ton/hr of steam)
So
= process steam to be met, kg/hr
CF = factor for continuous operation, 0.9-0.95
HR = actual working hours per year
• Heat Generation (for power matching):
S =
P x H xHR xCF
o o
PHR x10
Where, S = heat generation, TJ/year
Po
Ho
• Fuel Consumption:
F
=
η
= power to be met, kW
= enthalpy of process steam, kJ/kg
6
PHR = power to heat ratio, kWe/(ton/hr of steam)
3 . 6
engine
×
×
P
10 3
Where, F = fuel consumption, TJ/year
P = power generation, MWh/year
ηengine
×
= percentage of engine electric output
Table 2.5 Summary of the results for the diesel engine
Thermal Matching
5,000 kg/hr 13,000 kg/hr
Power Generating Capacity, kW 6,259 16,272
Power Generation, MWh/year 46,876 121,877
Excess(+)/Deficit(-) Power, MWh/year 34,161 109,162
Excess(+)/Deficit(-) Heat, TJ/year -55 111
Fuel Consumption, TJ/year 482 1,254
Power Matching
1,500 kW 2,430 kW
Heat Generating Capacity, kJ/kg 1,198 1,941
Heat Generation, TJ/year 25 40
Excess(+)/Deficit(-) Heat, TJ/year -133 -118