Hi,

I am trying to determine the optimum pipe diameter for a heat pump. To do this I am looking at the pump losses in just the sections of pipe where there is a single phase, i.e. I am excluding the condenser, evaporator and expansion valve-evaporator line. In order to do this it is important to properly model the heat exchange between the pipework and the air within the casing as changes in fluid temperature will result in varying volumetric flow rates.

Because it is possible to relate viscosity and Cp (and therefore h) to temperature I am attempting to define the walls heat transfer coefficient in sections based upon the temperature of the fluid within that section (I am aware that this will vary but hope to get a reasonably accurate value by using small pipe lengths). I have read in the SW help files that it is possible to define a heat transfer coefficient dependency based upon a goal value however I have been unable to find this option.

Could anybody give me direction to this option or inform me if I have misunderstood the help file?

I am using SW 2016 and trying to define a real wall boundary condition within flow simulation. Apologies for the poor quality image.

Thanks in Advance!

Rob