1、 Battery pack structure
The power battery pack is composed of a large number of single batteries. Its structure is related to the structure and quantity of single batteries, electrical connection mode, cooling mode, vehicle structure layout and other factors. The structural design of the power battery pack covers many aspects such as electricity, heat / current, machine, etc., so it needs to be integrated design. After determining the preliminary scheme, it is necessary to carry out multiple iterative calculations and coordinate with each other to meet the requirements of overall space allocation, thermal control requirements, electrical characteristics and other aspects, and then determine the final design scheme.
Because the thermal control subsystem of the power battery pack is associated with the structure of the battery pack, in order to analyze the thermal / flow simulation of the thermal management system, it is necessary to obtain the detailed structural information and the supporting thermal control hardware design scheme. The following figure shows the structural forms of several typical electric vehicle power battery packs. The thermal management hardware and structural design are perfectly integrated.
2、 Hardware structure of thermal management system: cooling system
Battery thermal management system technologies include natural cooling, forced air cooling, liquid cooling, refrigerant direct cooling, phase change heat storage, immersion cooling, semiconductor cooling and other technical methods; each technical solution has its own applicable scenarios; for new energy passenger cars, due to performance, safety, space volume, weight, and cost constraints, we recommend three technical solutions: liquid cooling, refrigerant direct cooling, and natural cooling. We believe that the current power battery liquid cooling technology is being widely used direct refrigerant cooling technology is a very promising development direction (low cost, low weight). Natural cooling technology is cost competitive on low cost models, but it is necessary to limit the operating conditions of the vehicle.
3、 Liquid cooling: liquid-cooled radiator
Take the battery liquid cold plate structure of Bolt EV as an example:
LG's battery system uses a flat-plate cooling method; it uses all the available cooling area of the soft pack cell!
(LG uses water-cooled aluminum plate as the cell heat conduction plate to achieve heat transfer)
