Heat Release Rate Formula :
The heat release Rate formula is the chemical energy released ΔQc(kj/kg) in kilo joule per kilogram is equal to the ΔW(kj/kg) in kilo joule per kilogram and addition of product is the work output ΔW(kj/kg) in kilo joule per kilogram and addition of chemical energy released ΔQh(kj/kg) kilo joule per kilogram and addition of Internal energy of the contents Δu(kj/kg) in kilo joule per kilogram. Hence the Heat Release Rate Formula can be written as,
ΔQc(kj/kg) =ΔW(kj/kg) +ΔQh(kj/kg) +Δu(kj/kg)
Where,
ΔQc → chemical energy released in kj/kg
W → work output in kj/kg
Qh → Heat transfer kj/kg
U → Internal energy of the contents in kj/kg
Sample Examples :
Example1 :
Calculate the heat released of a cylinder whose internal energy is 200 KJ/Kg and heat transfer is 520 KJ/Kg for the work 180 KJ/Kg?
Solution :
Given parameters are
Work= 180KJ/Kg.
Internal energy=200 KJ/Kg
Heat transfer=520 KJ/Kg
Substitute all the values in the given formula
ΔQc =ΔW +ΔQh +Δu
=180+520+200
=900 KJ/Kg
Therefore Heat release rate=900 KJ/Kg
Example2 :
Calculate the heat transfer for the work done 250 KJ/Kg? In a heat produced in a burner is 450 KJ/Kg and internal energy is 500 KJ/Kg.
Solution :
Given parameters are
Work=250kJ/kg
Internal energy =500 KJ/Kg
Heat transfer=450 KJ/Kg.
Substitute all the values in the given formula
ΔQc =ΔW +ΔQh +Δu
=250+500+450
=1200 KJ/Kg