Time-Accurate Conjugate Heat Transfer CFD Analysis of Multiple Cold Plate Configurations for Automotive Li-Ion Battery Thermal Management System 2019-01-0500

An efficient Thermal Management System (TMS) is crucial for superior performance of a Li-ion Automotive Battery Module, and longevity of the battery cells. Liquid-Cooled TMS, consisting of a coolant flow through a cold plate, offers higher rate of heat transfer compared to passive or forced-air cooled TMS, thus allowing cells to discharge at aggressive C-rates and higher ambient temperatures while maintaining the cell temperatures within an optimal range. The current study investigates the effect of a variety of cold plate configurations on the overall thermal performance of a Battery Module (BM) using time-accurate, conjugate heat transfer based three dimensional CFD analysis. Multiple cold plate configurations considered here are, (i) Parallel-Channel with uniformly distributed flow, (ii) Single-Channel Serpentine, (iii) Dual-Channel Serpentine, and (iv) Dual-Triple-Channel Serpentine. A BM consisting of 21700 form factor cells is analyzed at 1C discharge rate with a corresponding time-dependent heat generation. This heat generation function mimics the real-world BM operation where the irreversible joule heat generation varies with the internal resistance of the cells (DCIR) and generally increases towards lower State of Charge (SOC) of cells. Results for pressure drop, heat transfer rate, and overall temperature distribution of the cold plate and the cells are presented. The results of this study provide a framework for automotive designers to select a suitable cold plate configuration based on available pumping power, and to satisfy specific design criterion such as location of inlet/outlet ports and module hot spots.