| The research and development and industrialization of electric vehicles have become the mainstream of the development of the automotive industry.As the main energy storage mode of electric vehicles,the power battery has a serious impact on the performance of the vehicle.At the same time,in order to improve energy utilization,thermal management technologies around power battery packs and complete vehicles have received increasing attention.At present,the thermal management of electric vehicle power battery packs adopts liquid cooling integration.The cold plate component acts as a medium for the thermal interaction between the power battery pack and other components,and its heat transfer characteristics have an important influence on the performance of the thermal management system.The thesis combines the research group and the enterprise cooperation project “Development of Intelligent Temperature Control System for a Pure Electric Vehicle Power Battery”,and carries out structural design for the bottom cold plate of the power battery pack,and applies Fluent software to carry out the heat transfer characteristics and influencing factors of the cold plate components.The research and analysis were carried out.Based on the AMEsim simulation platform,the cold plate and air conditioning auxiliary liquid cooling battery system model was built,and the heat transfer performance of the cold plate components was analyzed.The research results show that the structural design scheme of the cold plate components proposed in this paper is reasonable.The main research contents of this paper are as follows:1.Based on the target model,the air conditioning auxiliary liquid cooling battery system architecture is proposed.Then,based on the single cell structure of the model,the battery case structure and the thermal conductive silicone sheet were designed from the perspective of engineering requirements and product development.On this basis,the preliminary analysis of the preliminary design of the cold plate structure and the theoretical analysis of the heat transfer characteristics of the cold plate are carried out.2.HPPC experiments,temperature rise experiments at different discharge rates and thermophysical parameters measurement experiments were carried out on the existing experimental platform of the research group.Through the combination of theory,simulation and experiment,the thermal model of single battery is established,and the heating law of the battery is analyzed,which provides the basis for the design of cooling plate structure of power battery pack and the design of vehicle thermal management structure.3.Combining with the heat dissipation demand of power battery pack,the quantitative indexes for evaluating the performance of cold plate are proposed,which are the average temperature,maximum temperature difference and pressure drop of battery pack.The effects of low temperature cooling,flow direction of coolant,different inlet flow rate,different inlet temperature and different cross-section width on the performance of cold plate are studied in depth.Potential problems are analyzed and boundary conditions and structural parameters are optimized.When the flow direction of coolant is one-way,one-way and one-way,the inlet flow rate is 4L/min,the inlet temperature is 18℃,and the cross-section width of the flow channel is 8mm,The temperature drop,uniformity and energy consumption of the cold plate are greatly improved.Finally,cold plate performance test bench was built to verify the feasibility of analyzing cold plate performance based on Fluent simulation.4.For the air conditioning auxiliary liquid cooling battery system architecture,the selection of key components was carried out.Secondly,based on the AMEsim simulation platform,the battery pack cold plate and the air-conditioning auxiliary liquid-cooled battery system model were built to verify the reliability of the model.The air conditioning auxiliary liquid cooling battery system was simulated to verify that the cold plate and its system have higher heat transfer efficiency for the power battery.The research content of this paper can provide guidance for the design and evaluation of cold plate of power battery pack and the research of integrated thermal management technology for power battery liquid cooling.The research results of this paper have reference value for the design and development of electric vehicle thermal management system. |
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