Research On Operating Characteristics Of Heat Storage Device Based On Cylindrical Phase Change Unit

In today’s society,as a new energy source,solar energy has brought a lot of convenience to mankind.It has the advantages of non-polluting and sufficient resource supply.However,the use of solar energy is unstable and intermittent in the four seasons,day and night,and regions.It is now necessary to store the waste heat for reasonable use by mankind to alleviate the needs of both supply and demand.Because the phase change heat storage device has high heat storage density,small size,and high heat storage and release efficiency,the phase change material(Phase Change Material,PCM)uses latent heat to absorb or release a large amount of heat during phase change,so the phase change energy storage has been It is widely used in various industries such as industry,environmental protection and chemical industry.The heat storage device is the core equipment in the heat storage system,and its performance directly determines the working efficiency of the system,so the research on the performance of the heat storage device has always been a hot spot in the field of heat storage.In order to improve the heat storage and release performance of the heat storage device,this paper encapsulates the hydrated salt whose main material is sodium acetate into various types of cylindrical phase change units,and designs 9 types of heat storage by changing the diameter and spacing of the cylindrical phase change units The device is used to study its heat storage and release performance through the single control variable method.In the case of maintaining the same quality of PCM,first of all,the heat storage of 5 different diameters of 50mm(25 pieces),60mm(16 pieces),80mm(9 pieces),106mm(5 pieces),118mm(4pieces)phase change units The device has carried out an experimental analysis of heat storage and release performance,and found that the difference in the diameter of the phase change unit has a greater impact on the overall heat storage and release efficiency of the device.The smaller the unit diameter(the greater the number)and the better the heat storage and release performance of the device evenly arranged.According to the principle of optimal comprehensive performance,a diameter of 60mm(16)was selected to continue the research on the effect of the change in the spacing between the units on the performance of the device.A total of 10 mm,20mm,30 mm,40.64 mm,50mm were designed for research and comparison.Through experimental tests,it is found that as the distance between the phase change units increases,the heat storage and release efficiency of the device increases but the increase is small.If the distance between the units is too small,the thermal overlap area will be larger,and the thermal impact between the units will be greater.Big.Finally,a device with a unit spacing of 50 mm is used to study the heat storage and release performance of the device at different inlet temperatures and different inlet flow rates.The study shows that increasing the inlet flow rate and increasing the temperature difference between the PCM and the heat transfer fluid(Heat Transfer Fluid,HTF)will increase The heat storage and release efficiency of the device.According to the actual PCM thermal physical parameters of each heat storage device,the relevant physical and mathematical models are established for simulation calculations based on the phase change heat transfer theory.By observing the change of the liquid phase rate curve and cloud diagram during the heat storage and release process of each heat storage device,explore the specific change process of PCM and HTF over time.This article uses a combination of experiment and simulation to explore the heat storage and release performance of a variety of cylindrical phase change unit heat storage devices,which provides reference value for the optimization of heat storage devices and engineering applications in the future,and provides help for energy conservation and environmental protection..