Hi there,(adsbygoogle = window.adsbygoogle || []).push({});

I am doing a project modelling and simulating a gas engine waste heat recovery system using an organic rankine cycle.

As part of this project I would like to size the surface area of a heat exchanger (if only roughly). I have found the appropriate formula using Q = U.A.LMTD and all the variables are fine and I believe I am calculating correctly but I'm assuming an overall heat transfer coefficient ("U") of ~400 W/m^2.K. I have no idea if this is accurate

The two fluids exchanging heat are an exhaust gas (heat source) and various refrigerants (R134a, R245fa), I was hoping someone might be able to suggest an accurate "U" for these fluids and if possible something to reference.

I don't have a fantastic knowledge of heat exchangers by any means, do I assume the heat exchange surface to be made from metal and is it relevant whether i specify plate or shell and tube etc?

Any help would be greatly appreciated, thanks advance for your time.

Ronan

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# Overall Heat Transfer Coefficient (Exhaust Gas to Refrigerant)

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