INVESTIGATION OF THE INFLUENCE OF THE CAPILLARY STRUCTURE OF A THERMOSIPHON ON ITS THERMAL POWER WITH HEAT CARRIERS R134a, R410a, R407c

Abstract

Thermosiphon (TC) is an evaporative-condensing heat exchange device, where the circulation of the working fluid (intermediate coolant) is carried out due to gravitational forces. There is no porous wick in thermosiphons, it is replaced by grooves of various geometric shapes. Structurally, thermosiphons are made in the form of hermetically sealed and elongated cylindrical vessels, the inner volume of which is filled with a working fluid. Liquid heat carriers are used as the working fluid, which can perform an aggregate-phase transition at operating temperatures observed during operation in a recuperative heat exchanger. In this article, author is talking about comparing the limits of thermal power of thermosiphons operating at operating temperatures of ventilation and air conditioning systems. At the same time, thermosiphons use freons R134a, R410a, R407c as the working medium, and the capillary structure of thermosiphons is represented in the form of grooves of the following types: a Ω –shaped groove, a rectangular groove and a triangular groove. For comparison, a thermosiphon with an outer diameter of 8 mm is used. The dependences of the thermal power on the operating temperature for all types of limitations of the heat transfer capacity of thermosiphons are presented, depending on the capillary structure used and the working fluid. The analysis of the best capillary structure of thermosiphons when using freons as a working body is carried out.