The performance of the evaporator of a finned-tube air-to-air two-phase thermosiphon loop heat exchangeer was studied by simulating the behavior of such systems while varying the lenght and the diameter of the tubes, the percent static charge in the evaporator, and the air-to-air temperature difference. All simulations were carried out using R-11 as the working fluid in copper tubes.

With the proper selection of the size of the tues and the percent static charge, a reasonably constant performance can be achieved over a modest range of temperature difference.

Units: Dual