| Based on the concept of sustainable development and responding to energy conservation and emission reduction policies,"oil to electricity"is an inevitable trend for the transformation and upgrading of marine power equipment.With the continuous upgrading of pure electric ship power equipment,the size and scale of its batteries are gradually becoming larger,the problem of heat dissipation of batteries needs to be solved urgently,and thermal management systems have become a current research hotspot.First,determine that the cathode material of the power battery is lithium iron phosphate,the specification is 3.2 V 500 Ah,calculate the electrochemical parameters of the single-layer battery,and establish a finite element model of the single-layer battery based on the COMSOL Multiphysics software.The working voltage-discharge capacity characteristic curve,working voltage-time characteristic curve,solid and liquid phase lithium ion distribution curve and current distribution curve of single-layer battery were drawn to verify the accuracy of the established lithium ion battery model.Determine the heat exchange scheme and technical indicators,and further establish the finite element model of the power battery and the finite element model of the heat sink.The temperature-time curve of the battery was drawn to verify the accuracy of the established electrochemical-thermal coupling model.According to the fractal theory,construct two self-similar and quasi-similar bionic fractal design schemes,calculate and determine the fractal ratio,fractal dimension and fractal series,and design the imitation honeycomb,imitation spider web,imitation lung trachea,imitation leaf according to the cold plate shape Four bionic flow channels.Secondly,under different magnifications and different temperature conditions,the thermal behavior of the single battery charging and discharging process is studied,the heat generation law is summarized,and data support is provided for the thermal characteristic analysis of the radiator.Taking the discharge process of a single battery as the research object,study the heat dissipation effect of the radiator,explore the influence of the discharge rate,the initial temperature of the coolant,the flow rate of the coolant,the number and position of the inlet and outlet of the flow channel on the maximum temperature rise and temperature difference of the battery;study the cooling The flow characteristics of the liquid,find the abnormal points of pressure drop and flow rate,optimize the structural design of the bionic flow channel,and determine the best cooling system control scheme with low pumping power and small.temperature rise.Taking the discharge process of large batteries as the research object,the heat dissipation effect of the bionic radiator was analyzed,and the advantages and disadvantages of the four bionic radiators in controlling temperature rise and uniform battery temperature were compared.The flow characteristics of the coolant in the four bionic flow channels were further verified.The energy-saving characteristics of the flow channel structure;for the flow characteristics and heat transfer performance of the two fractal flow channels of the imitation honeycomb and the lung trachea,the total pumping power and the total heat exchange amount are calculated to determine the optimal fractal structure and fractal of the bionic flow channel series.Finally,taking the maximum temperature rise and the maximum temperature difference as the optimization goals,taking the component of the coolant,the initial temperature,and the flow as the influencing factors,based on the response surface method,the Box-Behnken design is used.The test results show that:a single factor effect:q>c>T,the effect of the interaction of factors on the temperature rise:qc>q T>c T;the influence of a single factor on the temperature difference:q>T>c,the effect of the interaction of factors on the temperature difference:qc>c T>q T.The optimal combination of influencing factors was determined,and the flow rate,mass concentration,and initial temperature were 0.65cm~3/s,15%,and 305 K,respectively. |
PDF Full Text Request