The Effect of Heat Transfer Fluid Velocity on Heat Exchange Efficiency in Cold Energy Storage Tank: A Numerical Simulation Study

Abstract

Developing a cold thermal energy storage (CTES) technology is one of the most effective methods to solve energy shortage and environmental pollution all over the world. The current study deals with the modelling and simulation of a cold thermal energy storage tank consisting of an polyvinyl chloride pipe (PVC) heat exchanger partially filled with a phase change material (PCM). Water, as the heat transfer fluid (HTF), flows through the inner tubes and the outer one while propylene glycol as the phase change material fills. This paper focuses on studying the effect of the velocity characteristics on the heat transfer efficiency of polyvinyl chloride pipe (PVC) heat exchanger in cold thermal energy storage system by the numerical simulation. In this paper, the detail of heat transfer performance within the heat exchanger is numerically solved using computational fluid dynamics (CFD), for various velocity as well as different heat transfer for optimal design. Several results of changes in the temperature field at the outlet of the cold thermal energy storage tank are presented when the inlet water velocity changes from 1 m/s to 1.4 m/s. The results indicate that low input water velocity will provide better heat exchange efficiency. However, it is required to make sure that the flow inside the heat exchanger is the turbulent flow because the study uses turbulent flow modules.