An Investigation into the Performance of a Thermosyphon Heat Exchanger

Abstract

In this investigation, work was carried out to evaluate the thermal performance of Thermosyphon and its use as a heat exchanger in air condition test rig for heat recovery. Thermosyphon was chosen after considering the critical parameters that affects its performance such as temperature range (20 ͦ C– 40 ͦ C), container material (Cu) and working fluid (methanol) etc. Thermosyphon was built with 50% changing for its use in vertical position (inclination angle 90 ͦ). Testing of Thermosyphon at various heat loads (100 – 600 watt) was done. The results obtained showed that the temperature variation along its length was almost constant. Therefore, for the same geometry three thermosiphons were constructed and fitted inside the air conditioning test rig to investigate its performance for low temperature application (20 ͦ C – 40 ͦ C). Thermosyphon heat exchanger subjected to the temperature of the ambient air and temperature of the test chamber. After taking the overall temperature into account the experimental effectiveness was found to be 34.3 %. The effect of the variation of air face velocity (1- 6m/sec) on evaporator section of thermosyphon heat exchanger was also investigated. Air face leads to higher thermal heat transport the COP of the air conditioning test rig has which been also investigated to study the effect of thermosyphon heat exchanger on its performance. The COP observed was found to be improved to 4.73 from 0.76; however the achieved COP was below the theatrical COP (5.583). The study has helped to bring down the difference between actual and theoretical COP. Moreover, the effectiveness of thermosyphon heat exchanger using fins, increasing the no. of rows and decreasing the pitch to diameter ratio can be improved further.