Design And Performance Analysis Of High Performance Plate Phase Change Energy Storage Unit

High power density intermittent working electronic equipment requires reliable cooling and temperature control system to ensure its safe and reliable operation.The integrated system composed of a refrigeration unit and a liquid circulating cooling device containing a phase change energy storage module can meet the cooling and temperature control requirements of such equipment,and the system is compact and economical.This project develops a high-performance plate type phase change energy storage module for an integrated active cooling system for high power density intermittent operation electronic equipment.The main research work completed is as follows:?1?A high performance flat plate phase change energy storage unit is developedBased on the design concept of plate heat exchanger,the high performance flat plate phase change energy storage unit with a specification of 800mm×600mm×?4⁶?mm is developed by using the technology of heat conduction enhancement,setting and encapsulation of phase change energy storage materials.The energy storage unit is composed of high performance energy storage materials with high energy storage density and high thermal conductivity,and encapsulating materials.The phase transition temperature range,latent heat and thermal conductivity of high performance phase change materials are 23²8?,167.5J/g and 33W·?m·K?-1,respectively.The 0.3mm material is chosen as the sealing material.It has the advantages of light weight,easy processing,low cost and easy access.?2?An experimental device for measuring heat release and storage performance is designed and built.The experiment for measuring the fast heat storage and release characteristic of the high performance plate phase change energy storage unit is carried out by changing the inlet temperature and flow rate of the fluid.The result shows:In the process of heat storage,the instantaneous heat storage strength q continues to decrease,rapidly first and then slowly.Accumulative heat storage Q and the heat utilization rate are also increasing and rapidly first and then slowly.The comprehensive heat transfer coefficient K first decreases rapidly and then slowly fluctuates.Hot fluid flow only has a significant influence on K,inlet temperature has significant influence on K,Q,q and?.Under eight experimental conditions,the average value of K in the latent heat storage stage is within the range of 279⁴02W·?m²·K?^-1.The average value of Q in 10min is 2.67³.82kW,Q can reach 2300kJ and?is more than 80%,which basically meets the requirements under specific conditions.?3?In order to obtain better fluid flow velocity range,inlet temperature range and channel gap range,a more reasonable surface heat transfer texture structure of flat plate phase change energy storage unit is designed.On the basis of experimental research,the thermal energy storage of high performance flat phase change energy storage unit is numerically simulated with the software of FLUENT.The result shows:Considering the heat transfer rate and the heat storage time,The heat storage and release rate of the phase change energy storage unit is larger and the heat storage time is short when the flow rate is 0.05⁰.1m/s and the temperature is 32³6?.When the gap of the channel is increased from 2mm to 4mm,the heat release rate increases obviously.When the gap of the channel is more than 4mm,the heat storage rate does not increase and even reduces.Therefore,the recommended channel gap is between 4⁶mm.The heat transfer rate of the phase change energy storage unit can be increased by two kinds of texture of the concave pit and groove on the convective heat transfer surface,but the influence degree is smaller than other factors.Considering the complexity of the texture processing,the flat phase change energy storage unit with smooth surface is the better choice.In general,the high performance flat plate phase change energy storage unit is basically satisfied with the requirements,but the energy storage density and the combination mode of phase change energy storage unit need to be further optimized.