10 replies to this topic

[panagiotis]

Hello everyone,

 

I would like to share with you something that I was reading:

 

"The ratio of heat to electrical is approximately 3."

 

Have you ever see this factor 3? Where does this factor come from?

 

That is a way to convert thermal energy to electrical energy.

[breizh]

Hi,

Order of magnitude is correct, with the link underneath, I got 2.24 for NG.

Consider this source to preform calculations:

https://www.eia.gov/....php?id=667&t=3

 

Breizh

Attached Files

•  lower_and_higher_heating_values.xls   45.5KB   7 downloads

[panagiotis]

Hi Breizh,

 

I used the same link for NG, but I calculated the ratio 3.7.

[Bobby Strain]

I am confused. Please provide an equation, with units, to describe what you are referring to

 

Bobby

[panagiotis]

Actually, I used the material given by Breizh.

 

See the calculations below:

 

7.42 ft^3/kWh for natural gas-----> 0.21m^3/kWh_electr (eq.1)

 

The HHV for natural gas is 52,225 MJ/kg, which I converted to kWh/m^3 ----->

52,225 MJ/kg *(0,278/1/0,829) kWh*kg/m3------> 12,0358 kWh_heat/m3 (eq.2)

 

The ratio of heat/electrical can be calculated by multiplying eq. 1 with eq.2----->

 

ratio=0,21 m^3/kWh_electr. * 12,0358 kWh_heat/m3

ratio= 2,53 kWh_heat/kWh_electr.

 

(Ooopsy Breizh, I was wrong it is 2,53 the ratio eventually.)

[Bobby Strain]

I don't know what you are trying to demonstrate. The conversion between heat in btu to KWHr is 1 KWHr = 3412.14 btu. Taken from Katmar's Uconeer.

 

Bobby

[panagiotis]

I try to calculate the ratio of heat/thermal energy to electrical energy!

[Bobby Strain]

For what purpose?

 

Bobby

[shvet1]

Good reference is also able being found in EU BAT

https://eippcb.jrc.e...pa.eu/reference

 

Similar docs are issued for US.

[panagiotis]

I found a paper about heat pump distillation column, and they try to compare the electric power of the compressor with the reduction duty in the reboiler to compare it with the conventional distillation column.

[Bobby Strain]

So, you can easily accomplish that without your equivalence. What matters is $. And capital cost. And other operating costs.

 

Bobby