Simulation and optimization of de-icing two-phase closed thermosyphon based on CO2 work fluid

Abstract

Two phase closed Thermosyphon (TPCT) are subcategory of heat pipes based on natural circulation loop (NCL) with high performance heat transfer capacity and variety applications which are used to transfer a large range of heat through different temperatures. In general, heat pipes are a sealed closed pipe with high length-to diameter ratio, which operate based on latent heat of evaporation and condensation to transfer heat. The system equipped with capillary wick structure to facilitate the fluid transport where the gravity act as opposition or insufficient force through fluid movement. Two phase closed Thermosyphon (TPCT) is a type of heat pipe, which has no capillary wick structure and the fluid transport by gravity as a directional force. Heat pipes technology has proven their high performance and efficiency by considering all aspects of their related parameters and practical in many industries from cooling nuclear reactors to transferring heat from computer chipsets to the fan. Proper heat transfer capability with the ability to work with large range of temperature differences at both ends of the system has made the analysis of this technology very important. What is very important when using thermosyphon is how to design and consider all the parameters and variables of the system. In addition to design complexities for different applications and considering the wicks system, optimizing and increasing the heat transfer capacity of a TPCT depends on the analysis and selection of many related parameters, including its geometric dimensions and the type and amount of work fluid needed to operate confidently. These researches could have more value when it aim is to design a system that can use and transfer geothermal energy as a clean energy source. This research is based on the simulation a thermosyphon buried in the earth receives the heat energy needed to evaporate its work fluid from the geothermal energy and transfers this energy to the earth's surface in order to melt snow in winter through a thermosyphon mechanism. In addition, by applying numerical optimization on the dimensions and work fluid ratio inside the thermosyphon, in this article, an attempt has been made to present the results of this analysis in different categories by considering its different applications. Finally, by applying CFD analysis on the designed thermosyphon, the fluid behavior in thermosyphon is assessed under mentioned environmental conditions.

Date	18 Dec 2020
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Louis Lamarche (Supervisor)