How to calculate heat exchanger effectiveness when condensation occurs
How to calculate heat exchanger effectiveness when condensation occurs
(OP)
I've been testing an air-handling unit with a recuperative counter-flow heat exchanger. Everything is smooth when I calculated effectiveness and temperature efficiency when there is no condensation.
However, as to my knowledge you cannot calculate the effectiveness when condensation occur, at least not with the same equations. I'm using the e-NTU, which is only valid for dry air.
Can anyone please give some advice on how to calculate the effectiveness when condensation occurs?
Cheers
Kep
However, as to my knowledge you cannot calculate the effectiveness when condensation occur, at least not with the same equations. I'm using the e-NTU, which is only valid for dry air.
Can anyone please give some advice on how to calculate the effectiveness when condensation occurs?
Cheers
Kep





RE: How to calculate heat exchanger effectiveness when condensation occurs
Hope that helps.
RE: How to calculate heat exchanger effectiveness when condensation occurs
I thought it was a simple matter to calculate the effectiveness when considering latent heat.. but maybe it's complicated? I can't find information anywhere online.. Maybe I should just write in the report that the effectiveness is lower probably because of condensation and since it's not readily calculated bla bla etc etc.. something =)
Thank you for the help Dan =)
RE: How to calculate heat exchanger effectiveness when condensation occurs
Either way the condensation shouldn't be ignored, it takes quite a bit of energy to lower the temperature of water vapour enough so it condenses out as a liquid as compared to the same amount of air - it is signifigcant. Even if you had some crude way of measuring the weight of a drip pan before and after testing or the entire coil assemble, if possible? you could work out the energy it took to transform the water vapour into liquid. If you know the entering air temp. and relative humidity, and then the exiting air temp, and relative humidity you could do it that way also, probally easier than measuring and weighing condensed water :]
It kind of sounds like you are doing doing performance testing for a product.
RE: How to calculate heat exchanger effectiveness when condensation occurs
RE: How to calculate heat exchanger effectiveness when condensation occurs
RE: How to calculate heat exchanger effectiveness when condensation occurs
RE: How to calculate heat exchanger effectiveness when condensation occurs