Measuring the efficiency of Heat exchangers
Measuring the efficiency of Heat exchangers
(OP)
Hello all, I would be grateful if someone could provide me with a little insight.
I am tasked with writing some software to do calculations and control a system to measure the efficiency of heat exchange systems.
My problem is that I am from a chemistry background, and I strongly feel that the design of the experiment is flawed; it is not my area and the engineers that have designed the system have dispelled my concerns.
My chief concern is that the system draws air from the external environment, and the relative constituents of the air is not measured; it is my assertion that moisture or other emissions from neighbouring business will be able to significantly alter the specific heat capacity of the air in a system with a large volume of air; and thus invalid any comparisons made with the system.
Does anyone have any experience in this area? Are my concerns well founded?
I just want to fit a GC machine and only operate the machine within certain parameters...I figure buying in a huge volume of compressed air would be preclusively expensive.
I am tasked with writing some software to do calculations and control a system to measure the efficiency of heat exchange systems.
My problem is that I am from a chemistry background, and I strongly feel that the design of the experiment is flawed; it is not my area and the engineers that have designed the system have dispelled my concerns.
My chief concern is that the system draws air from the external environment, and the relative constituents of the air is not measured; it is my assertion that moisture or other emissions from neighbouring business will be able to significantly alter the specific heat capacity of the air in a system with a large volume of air; and thus invalid any comparisons made with the system.
Does anyone have any experience in this area? Are my concerns well founded?
I just want to fit a GC machine and only operate the machine within certain parameters...I figure buying in a huge volume of compressed air would be preclusively expensive.





RE: Measuring the efficiency of Heat exchangers
Regards
StoneCold
RE: Measuring the efficiency of Heat exchangers
Is this for school?
TTFN
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RE: Measuring the efficiency of Heat exchangers
Compare the properties of these two gases
CP BTU/LBMOL/R 6.9697
CP BTU/LB/R 0.2416
CV BTU/LBMOL/R 4.9737
CV BTU/LB/R 0.1724
CP/CV 1.4013
DENSITY LB/FT3 0.074333
CP BTU/LBMOL/R 6.9991
CP BTU/LB/R 0.2450
CV BTU/LBMOL/R 5.0022
CV BTU/LB/R 0.1751
CP/CV 1.3992
DENSITY LB/FT3 0.073607
The top is bone dry air, the bottom is 100% saturated air both at 72F and 14.696 psia.
CP BTU/LBMOL/R 6.9688
CP BTU/LB/R 0.2415
CV BTU/LBMOL/R 4.9735
CV BTU/LB/R 0.1724
CP/CV 1.4012
DENSITY LB/FT3 0.069272
Here is the same dry air only with a filter having a 1 psi pressure drop
The pressure has a larger effect than the humidity.
put your money on measuring the T&P and forget the composition.