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This publication extends on a holistic system design approach by implementing an efficient simulation methodology to design a robust cooling system for a liquid cooled battery module. After gaining insight into the functionality of the system and its components, the most promising parts for redesign were selected using a method called Extended Target Weighing Approach (ETWA). Because of this redesign, the cell mount was reduced in height and the cooling system topology parallelized to lower pressure losses. The design of the new cooling system geometry is explored. The parameter optimization is carried out with a simplified 1D fluid dynamics model. To verify and validate the 1D-simulation, a more detailed 3D-simulation is used at bespoke crucial times during development. The main boundary conditions were keeping the pressure losses at or below its reference level from the module’s predecessor, while designing a robust system in terms of flow rate distribution in the parallel channels. The result was a system behaving almost indifferent to changes in temperature or total flow rate with the channels individually changing less than 5% of total flow rate and all channels staying in the range between 20% to 32% of total flow rate at all times. The overall system pressure drop could be brought down to half of its reference value. The two simulations were achieving similar results, eventually deviating less than 5% relative to each other in simulated flow rates and pressure losses.

This publication investigates the process of improving an existing liquid cooled battery module in terms of lightweight design and cooling capabilities for production processes suitable for series production by using a holistic approach. It starts by identifying components with too high efforts using a method called Extended Target Weighing Approach (ETWA) and continues using complementary CFD and thermal simulations to guide the conceptualization of new solutions methodically. While conceptualizing and designing the parts to improve on key aspects of the battery module, a new tool was developed to select the best combination of material, process and manufacturing for these components. For this particular battery module, using the ETWA, we identified the cell mount, the housing and the plethora of components responsible for the sealing functionality as too heavy. Due to this, simulations of the coolant flow and temperature distribution were performed to guide the design choices for the cell mount. The thermal and CFD simulations revealed that a reduction of the initial cell mount height is possible while keeping the maximum temperatures within reason. Housing concepts were developed considering design limitations due to the manufacturing processes recommended by the selection tool. The used tool chain enabled an objective and comprehensible decision-making to optimize the battery module considering lightweight design and cooling capabilities.