Investigation On Thermal Performance And Pressure Loss Of The Fluid Serpentine-channel Cold-plate Used In Thermal Management System Of The Battery Pack

With the increasing tension of energy and the deterioration of environment,it is difficult to meet the requirements of energy and environment by just improving the performance of internal-combustion engine.Under the circumstances,new energy vehicles especially electric vehicle;ushered in the great development.As an important component part of the electric vehicle,battery has been a key factor restricting the performance and life of electric vehicles and the temperature of battery has great impact on performance of battery.Thus,the battery thermal management system(BTMS)is necessary.Currently,the mainstream battery thermal management system is air cooling system while liquid cooling system has got more and more attentions due to the increasing energy density of battery.The current researches of liquid cooling system are mostly focus on the thermal performance,seldom has so far been performed on pressure loss of fluid flow in channel.In liquid battery thermal management system,the liquid is driven by the pump powered by the battery,which means more pressure loss will consume more electric power of battery,resulting in shorter mileage of vehicles.Thus,it is very necessary that research on the thermal performance meanwhile study on the pressure loss of channel.The thesis is supported by key project of Changsha Science and Technology Bureau[kh1601129],integrated service platform for Collaborative Innovation of New Energy Vehicles[2016XK2008]and China Power Valley Innovation And Entrepreneurship Development Program[ZJ/2016-006].Using the method combined by theoretical analysis,numerical simulation method and experimental verification to research the thermal performance and pressure loss of serpentine-channel cold plate with different structure parameter on microwave regeneration.The main innovative points are as follows:(1)A serpentine-channel cold plate with varing characteristics is created and a model of thermal resistance which represents the cooling effect of cold plate is built and its objection function is created.By changing the structure parameter and the velocity of fluid,different thermal resistance are obtained and the laws of cooling system thermal performance are got through comparisions between these thermal resistance.(2)A type of U-tube and straight pipe are created to research the friction pressure loss coefficient A and excess pressure loss coefficient C respectively.The ? and ? are obtained by pressure loss simulation using FLUENT software and the object function about pressure loss is created.(3)Combining thermal resistance model and pressure loss model,an object function about thermal performance and pressure loss is created and a methodology which can quickly find the optimal structure about thermal properties and pressure loss of serpentine-channel cold plate used in battery thermal management system is created basing on this object function.