Boiler Efficiency Calculation Inquiry
Boiler Efficiency Calculation Inquiry
(OP)
Hello experts and professionals,
I want to confirm one thing regarding boiler efficiency calculation method.
My feed water temperature at dearator tank is 95C after which it goes to air preheater before going finally into boiler. The water temperature after air pre heater is 110 C. So while calculation boiler efficiency via direct method, I have to take value of feed water at 95 C or 110 C?
My vote goes for 95 C since it is the heat given to water for heating. The rest temperature is raised via exhaust gases emission which should not be included as it is heat extracted from something which is not produced separately for water.
Please confirm.
Also, if anybody like to help me confirming/clarifying following,
To get natural gas fuel in KJ/KG from BTU/SCF, I am doing following steps
1- Multiplying BTU/SCF with KJ/cubic meter.
2-Dividing this figure by natural gas density (kg/cubic meter) to get finally KJ/KG
A much thanks in advance.
I want to confirm one thing regarding boiler efficiency calculation method.
My feed water temperature at dearator tank is 95C after which it goes to air preheater before going finally into boiler. The water temperature after air pre heater is 110 C. So while calculation boiler efficiency via direct method, I have to take value of feed water at 95 C or 110 C?
My vote goes for 95 C since it is the heat given to water for heating. The rest temperature is raised via exhaust gases emission which should not be included as it is heat extracted from something which is not produced separately for water.
Please confirm.
Also, if anybody like to help me confirming/clarifying following,
To get natural gas fuel in KJ/KG from BTU/SCF, I am doing following steps
1- Multiplying BTU/SCF with KJ/cubic meter.
2-Dividing this figure by natural gas density (kg/cubic meter) to get finally KJ/KG
A much thanks in advance.
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RE: Boiler Efficiency Calculation Inquiry
RE: Boiler Efficiency Calculation Inquiry
RE: Boiler Efficiency Calculation Inquiry
Btu/scf x 379.5 = Btu/lb mole
Btu/lb mole x 1.055 = kJ/lbmole
kJ/lbmole x 2.204 = kJ/kgmole
kJ/kgmole / FG mol wt = kJ/kg
If you are looking for overall eff, use 95degC, the feed temp to the BFW preheater / economiser.
RE: Boiler Efficiency Calculation Inquiry
Think of the boiler as the engine in a car. When an economizer is added, that doesn't change the boiler - it's like adding a another higher gear to the transmission in a car. The car will get improved fuel economy, and will go faster, but that modification had nothing to do with the engine. The engine itself remained unchanged.