Battery Cooling Function in Structural Brackets

Abstract

In the current production of battery packs at Volvo Cars, there are separate cooling plates for thermal management of the battery modules and cells. To hold the cooling plates and the modules in place, separate support bracket with load carrying and crash withstanding capability is used. The two component design of cooling plate and bracket causes issues in the rigidity of the assembly due to tolerance stack up as well as being a complex and bulky solution. The objective of the thesis work was to find an integrated solution that would provide both the required cooling functionality and rigidity to hold the parts in place. Since the battery pack is already in production, the development task was perceived as an incremental product of the existing part and thus the scope was set to keep the changes as minimal as possible from the existing design. The current design was benchmarked thoroughly, the performance was understood and the key requirements from the product were noted down in a requirements list. A functional analysis for the system was done to note down the important functions of the system. Based on the functions of the system, solution principles were brainstormed and developed. The solution principles or concept combinations were screened and evaluated using normative assessment methods like Elimination Matrix and Pugh Matrix. A concept involving aluminium die casting of the part was the winning concept and embodiment of design was carried out following the concept screening. During the embodiment design stage, focus was towards manufacturing feasibility, joining techniques, assembly techniques and feasibility. Finally, a cost, assembly tolerance and weight comparison between the current design and proposed design was carried out and scope for further work is recommended to Volvo Cars.