CFD Analysis of Dual-Phase Flows Inside Helically Coiled Tubes in Vapour Compression Micro-Refrigerator

Abstract

This study focus on experimental exploration of heat transfer by helical coil. Helical pipe of circular cross section is used widely in variety of applications due to inexpensive and easiness in production. Enhancement of heat transfer by helical pipe is more prominent than in straight pipe, which has supported by many literatures. Controlling pressure drop (which is also a significant factor) to enhance heat transfer in the helical pipe. Modeling of dual phase, especially fluid – vapor flow under adiabatic conditions inside a flat helical tube utilizing CFD examination is difficult with the accessible dual phase models in fluent due to constantly changing flow patterns. In the present investigation, CFD examination of two phase flow of refrigerants inside a level helical pipe of inward diameter across, 20 mm and 100mm length is completed utilizing homogeneous model in adiabatic conditions. The refrigerants considered are R290 and R134a. The investigation is performed at saturation temperatures with fluid flow rates to assess the nearby frictional weight drop. Flow characteristics, velocity, pressure drop, turbulent kinetic energy, and temperature contours along the total length of the coil are to be analysed. Velocity, pressure drop, turbulent kinetic energy, and temperature distribution of multi-phase flow inside the pipe also to be analyzed. By utilizing homogeneous model, normal properties are acquired for each of the refrigerants that are considered as multi-stage pseudo liquid.