Numerical Simulation Optimization Of Phase Change Thermal Process In Ice Hockey Cold Storage System

The ice storage air conditioning uses night cooling and daytime cooling to achieve peak load reduction,capacity reduction of refrigeration unit equipment,and balance of grid pressure.In this paper,Fluent numerical simulation software is used to establish the flow and heat transfer model of single ball ice and ice storage tank system,and the Solidification/Melting model and turbulence model are loaded,taking into account the change of density of phase change material with temperature in the process of single ice ball phase change.The influence of the coolant flow direction in the ice storage tank and the position of the brine inlet on the cold storage process was studied.Do the following work:The general laws of the freezing and solidification processes of a single ice hockey are studied.The changes in the internal temperature and the interface between solid and liquid phases are analyzed.The influences of inlet temperatures of different radii and brine on the cold storage and release processes are studied.The simulation results show that: The larger the ice storage radius,the longer the phase change takes place.However,the ball diameter should not be too large to control the cold storage time.The greater the temperature difference between the coolant and the ice ball,the more favorable the phase transformation is.With the progress of heat,the phase transition time is also shortened.Considering the difference between the solid-liquid phase density and the solid-liquid phase density difference,due to the effect of natural convection,the time difference of phase transition is shorter and the simulation result is closer to the actual situation.The cold storage process of the ice storage tank was simulated,the heat transfer conditions of the cold storage tank under the convection state were studied,and the influence of the different coolant flow speeds and inlet and outlet positions on the ice storage characteristics was optimized.The structure of the ice storage tank was optimized.The simulation results show that the greater the flow rate of the coolant,the more convection phenomenon in the ice storage tank,the faster the solid-liquid interface moves,the shorter the storage time,and the more conducive to heat transfer;the cold refrigerant flows from the inlet into the ice storage tank first There will be a period of laminar flow,which will enter the turbulent flow stage during the impact of the ice hockey,and will be accompanied by local recirculation and vortices.The closer to the interior of the tank,the more rapid the change of the velocity vector of the refrigerant,and thus the acceleration of the ice hockey.Heat exchange,so it is possible to design a wrinkle,gully,bulge,depression,etc.in the spherical shell to increase the disturbance of the fluid;the greater the inlet flow velocity,the larger the Nusselt number,the between the refrigerant and the ice ball The larger the convection heat transfer coefficient,the larger the drag coefficient,so the inlet flow rate must not be excessively increased;the greater the inlet flow velocity of the refrigerant,the faster the outlet temperature reaches a stable state;the refrigerant is used from The flow pattern at the bottom of the inflow to the top is larger than the convection heat transfer coefficient at the top of the inflow to the bottom,which is more conducive to heat transfer,and this advantage is more pronounced with the increase of the flow rate of the refrigerant.Furthermore,the structure of ice hockey and ice storage tanks has been optimized to achieve maximum energy utilization and can play an active role in the development of energy conservation and emission reduction.