KC-2844 -- An Analysis of Pressure and Temperature Measurements Along a Capillary Tube-Suction Line Heat Exchanger PDF

The pressure and temperature distribution along a capillary tube-suction line heat exchanger was experimentally measured. Specifically, capillary tube pressures, tube wall temperatures, and suction line fluid temperatures were measured at one-foot intervals under conditions similar to those of an actual operating R-12 refrigerant system. The results showed that the behavior of a capillary tube with heat transfer is considerably different from an adiabatic capillary tube. An analysis of the results provided significant insight into the operation of a capillary tube-suction line heat exchanger, resulting in several new conclusions. Specifically, the transfer of heat increases the length of the two-phase region while simultaneously reducing the flow restriction. Additionally, the rate of heat transfer increased along the heat exchanger toward the exit, so that most of the heat transfer occurred in the two-phase region. Several other important observations also are discussed in the text.