03. Electronics Packaging and Thermal Management

Electric vehicles (EVs) are developed to decrease greenhouse gas emissions from the transportation sector. However, EV performance depends on the performance of the battery as the energy source. EV battery temperature must be kept at its optimal condition between 15-45oC to maximize its performance, prevent degradation, and prolong lifespan. Hence, a battery thermal management system (TMS) plays an important role. Loop heat pipe (LHP) is a passive cooling device that has been gaining interest recently to manage EV battery temperatures. A battery pack consists of several battery cells according to their power capacity. Despite being investigated extensively, most LHP studies consider only a single heat source for every single LHP evaporator. This paper aims to fill the gap in the literature by tackling the dual heat sources problem using a single evaporator. A modified copper evaporator with additional grooves on both surface sides was designed and manufactured. A stainless-steel screen mesh was used as the capillary wick. Two cartridge heaters were incorporated into two stainless steel blocks, acting as battery simulators, the heat sources for this study. Deionized water was used as the working fluid. Several thermocouples attached to the national instruments data acquisition (Ni DAQ) 9214 were used to measure the temperatures along the LHP system. In this study, the LHP was tested at various heat loads. The influence of the filling ratio on LHP start-up performance was investigated. The results show that LHP was successfully started up at 40-120 W. The lowest evaporator surface temperature of 44°C was achieved at a filling ratio of 60% when operating at 40 W, which provides the best thermal performance by keeping the battery operating temperature at ideal conditions. The minimum thermal resistance obtained was 0,18±2,4%.