A numerical simulation was performed to study the effect of axial spacing variation between two legs of a U-bend pipe on heat dissipation, used for condenser heat transfer, in a closed-loop water-cooled earth-coupled heat pump. Three problems were studied. The first used a uniform conductivity model, and the second one assumed: a linear relationship of soil conductivity with temperature. By assuming uniform but different average outside pipe surface and earth temperatures, it was found that an increase of 20% in heat transfer, over the base case of pipes touching each other, can be achieved by spacing the pipes about 0.18 m apart. A transient analysis showed increases on the order of 40% over the base case. A spacer design using materials similar to the pipe is suggested to keep a uniform spacing, and it will also help in curbing “thermal leakage” between the two legs of the loop.
Units: Dual
Citation: ASHRAE Transactions, 1988, vol. 94, pt. 2, Ottawa
Product Details
- Published:
- 1988
- Number of Pages:
- 11
- File Size:
- 1 file , 970 KB
- Product Code(s):
- D-OT-88-3150
