A Study on the Heat Transfer Performance of a Thermal Storage Heating Device

Abstract

Recognizing the challenges faced by electric busses that must utilize a portion of their battery energy to heat the passenger compartment in colder locations, thus reducing their driving range, this work has devised an effective solution to this issue. A compact single-row thermal storage system was designed to fulfill the heating needs of electric busses. Thermal resistance investigation demonstrated that this device provides exceptional insulating efficacy and heat dissipation rate. This study utilizes an aluminum-silicon alloy as the phase transition material for heat storage, with 316 stainless steel as the encapsulating medium. Air serves as the heat exchange medium, and a numerical model has been established. A small-scale experimental apparatus has been established to verify the accuracy of the numerical model. The study offers a comprehensive examination of the flow dynamics of the heat exchange fluid in storage tanks of varying diameters, the solidification pattern of the aluminum-silicon alloy phase change material, and the attributes of temperature distribution. Under equal inlet temperature and flow rate conditions, increased tank diameters lead to prolonged solidification durations for the aluminum-silicon alloy, elevated output temperatures, and a more heterogeneous temperature distribution inside the thermal storage medium. Elevating the inlet temperature in tanks of identical diameter results in increased exit temperatures and extended solidification durations for the aluminum-silicon alloy. Conversely, maintaining a constant intake temperature while augmenting the inlet flow rate reduces the output temperature and decreases the solidification duration of the aluminum-silicon alloy.