Latent Heat calculation

[skumar84]

I have to model a condesing economizer for a steam boiler ...to model that I have to calculate both sensible and latent heat ...

Sensible heat is pretty straight forward with the equation Q=mcp(t2-t1)

latent heat part is complex as it has to do something with dew point temperature and partial pressures ....I am not sure what procedures i have to follow ....

Mass flow rate of flue gas (m)= 11800 lbs/hr
cp of flue gas = 0.34
Temp of flue gas = 450 F
ambient = 70 F

Help needed in finding out the latent heat that can be obtained by the economizer from the flue gas ...flue has components assuming to be o2, CO2, H20, and N2

 

[RR79]

Hello Skumar84!
Why would you want to calculate the latent heat?
Normally, we should avoid condensating water in the flue gas stream as it may cause corrosion over all the carbon steel surfaces in the economizer and after it.

The main data necessary for a preliminary design of an economizers is:

Fuel (?)
Flue gas inlet temperature (450 F !)
Flue gas flow rate (11800 lb/h !)
Water inlet temperature (?)
Water inlet pressure (?)
Water flow rate (?)


Send me the information and I can use our company´s software to design it. Regards,

RR79

http://www.jlj.com.br

 

[skumar84]

thanks @ RR79

The use of condensing economizer is to extract the latent heat from flue gas to an extent unlike normal economizers...

Fuel - natural gas
Water in temperature - 75 F
Water inlet pressure - assume atmospheric
Water flow rate - 20 gpm