Research On Influence Of Annular Water Distributor On Thermal Performance Of Hot Water Storage Tank

With the increasingly serious energy crisis and environmental pollution,the reserves of non-renewable resources are limited,and the development and utilization of renewable resources are imminent.Solar energy is huge,inexhaustible,clean,pollution-free,wide distribution,is one of the most ideal clean energy;But its instability,intermittent shortcomings also bring great difficulties to the development and utilization.The solar heating system is one of the most perfect solar energy resources utilization projects at present.The phase change heat storage tank plays a key role in solving the problem of the mismatch between supply and demand of the system.With the development of science and technology,how to make more efficient use of solar energy resources and improve the heat storage and release performance of phase change heat storage tank has become the main research direction of many scholars.In this paper,the structure of the second generation phase change heat storage tank is optimized.To avoid temperature dead zones,adopt the way into the out of work,inlet arrangement in the center of the bottom of the tank geometry,design a kind of annular fabric water intake structure,and select the present study more box type structure of water tank and the traditional type straight into the water tank experiment and simulation,and by changing the velocity of water inflow temperature conditions,It is found that the strong heat convection phenomenon is formed in the annular water distribution tank during the heat storage process,and the heat storage efficiency is accelerated.The oblique temperature layer is thicker,and there is no temperature dead zone.The faster the inlet flow rate is,the higher the heat storage efficiency is,and the higher the inlet temperature is,the higher the heat storage efficiency is.In the process of heat release,the temperature stratification phenomenon of the annular water distributor tank is obvious,the heat release efficiency is the highest,and the heat waste is avoided.With the increase of influent flow rate,the delamination effect and heat release efficiency of the three types of water storage tanks decrease,but the decrease speed of the annular water distribution tank is the least.Further research on circular water distribution device to phase change heat storage water tank unit(heat)storage,the influence of heat release process,this paper chooses two kinds of porosity,comparing the regenerative ball combination in different velocity and inlet temperature under the condition of experiment and simulation,found in the process of heat storage,the layers of PCM temperature,show no dead zone temperature.The higher the influent velocity is,the higher the heat storage efficiency is.The higher the inlet water temperature,the higher the heat storage efficiency;The larger the porosity,the higher the heat storage efficiency.In the process of heat release,the annular water distributor can effectively restrain the disturbance of the inlet water flow to the internal temperature field,so that the heat storage tank keeps a good temperature stratification.The higher the flow velocity,the higher the heat release efficiency of PCM,the higher the porosity,the higher the heat release efficiency of PCM;Finally,Fluent is used to simulate the variable temperature inlet condition,and the heat release time is longer than that of constant temperature inlet.In this paper,the research method combining experiment and simulation is used to develop the annular water distribution device and design the third-generation heat storage tank with no temperature dead zone and better thermal stratification.The theoretical basis and technical support are provided for the further research on the phase change heat storage device,and the reference value is provided for the promotion and application of the solar phase change heat storage heating system.