[ytszazu]

There are two heat flows entering and mixing together. assume balanced and proper mixing.

A) Incoming:

Gas 1:
1100 C
13644 m3/hr
Cp = 1.73 kj/kg.K

Gas 2:
80 C
Cp = 1.00882 kj/kg.K

B) Outgoing
160 C
Cp = 1.12

There are two unknown values here. So an exact answer isn't necessary

What I would like to know is for example,
If we set the output volume to 120000 m3/hr,

Hiow much volume of the second gas stream (the 80 C one) that we need?

Regards,

Yong Tze Shoong.

[Donaldson Tan]

Your Cp is quoted on mass basis, but I do not have the mass flowrate of any stream, only volumetric.

I can assume ideal gas behavior conveniently if your Cp is quoted on a molar basis.

[ytszazu]

I apologise for the extremely late reply.     

Okay, the gasses for both streams are as follows:

Gas one is furnace flue gas (mixture of 1 part H2O, 2 parts CO2 and 8 parts N2) by volume
H2O density = 18g/mol
CO2 density = 44g/mol
N2 density = 28g/mol
Pressure is considered ambient, temperature as indicated in first post.
My mistakes on the Cp, it is 1.37kj/kg.K at that temperature.

Gas two is air.
Average density is 1.2 kg/m3

Regards,

ytszazu

[Donaldson Tan]

ytszazu:

If you do a degree of freedom analysis, you would realise that your system does not have the degree of freedom you think it has.

Deduce the molar mass of air and the flue gas

Calculate the molar flowrate of air and the mixed gas.

Then do a simple energy balance..