SFC and Heat rate


Thread Starter


Hi friends;
I want to know what is the difference between SFC (Specific fuel consumption) and heat rate.

Please tell me how i calculate the SFC and heat rate of gas turbine. I also want to know what effect of LHV on both above parameters. I want to calculate SFC in BTU/HP-Hr.

I have the LHV value is 18800 BTU/SCF and HP is nearly about 3900 HP. SG of natural gas is 0.6325.

Please guide on this both issue. I appreciate if anyone send me a article on both parameters of split shaft gas turbine.
Thanks phil corso for typing a few letters. But where i find send me link

>Asraf... Search "Eng-Tips!"
>Regards, Phil Corso
How i contact with you? Please post this article on the above post email id. Thanks

>Ashraf... I used AOL Search Engine. If
>you still have difficulty, please
>contact me off-list!
>Phil Corso
> Sir i search but i cannot find it. I think thread is closed.

>>Ashraf... "Eng-Tips" Thread # 666-144149


hey sir, i want it need that answer too.. i'm student but i don't no how can get heat in the combustion chamber with heat rate.. plis sir if you can contact to me i glad.. mi mail is [email protected]


Heat rate is simply the ratio between the total amount of heat and energy generated. Let see this example

Heat Rate = Total heat supply (kJ)/Total energy generated (kWh)

We have variations in terminologies depends upon what you want to define

1. If you use LHV then you call it LHV heat rate

2. If you use HHV then you call it HHV heat rate

3. If you define for unit gross (LHV/HHV) then you call it unit gross heat rate

4. If you define for turbine alone then you call it turbine heat rate(LHV/HHV)

SFC is the ratio between energy generated and the quantity of fuel to produce it.

SFC= Unit generated (kWh)/kg of fuel to produce it

Still you have to define whether whether the value is based on HHV or LHV.

P/s Asyraf

You are from Polytech Kuantan right? Kuantan used to be my hometown during my child hood. It was almost 40 yrs ago.
Sir its good explanation. We used LHV its value near about 17295 BTU/Lb. And the unit of energy generated we used HP/Hr. I want to know how can i convert PPH into MMBTU/hr. We measure fuel in PPH and our SFC unit is BTU/HP-HR.