Simulation Study On Performance Of Chilled Water Storage Tank Based On Natural Striatified Theory

The air condition system with chilled water storage is an important measures to move the electricity demand from the peak to the valley.And the natural stratified water storage system has been widely used,as a more economical way to store large amount of cold.The geometry,flow rate and temperature difference are important factors affecting thermal performance,which determines the capacity and economy of the whole process.In this paper,the influence of height-to-diameter ratio(HD),shape,flow rate and temperature on the performance of storage tank under different insulation conditions is studied by numerical simulation.The shape and flow parameters of numerical model are set according to the previous experiment,and the model verification is carried out.The charging efficiency are used as the index to evaluate the performance.The inlet diffuser was simplified and verified.The cold storage performance of tank with different HD,shape,f low rate and temperature is simulated and analyzed under adiabatic condition.The performance of the cylinder and the rectangular tank is nearly the same.When the flow rate is 1.6L/min,the larger the HD,the better the cold storage performance,but this effect decreases with the increase of HD.Larger flow rate and temperature difference are not conducive to charging efficiency.Under the circumstances,the performance of tank is becoming firstly better and then worse with the increase of the HD.Because of the fact that the adiabatic tank does not exist,simulation and analysis under nonadiabatic conditions are also carried out.The effect of HD on performance is studied under different insulation thickness.The simulation results are close to the adiabatic condition when the thickness of insulation is 3 cm.If the thickness of insulation is 1 cm,the cold storage performance of rectangular water tank is significantly worse than cylindrical tank,and the performance of tank is becoming firstly better and then worse with the increase of the HD.In general,the recommended HD range is 4~8.The transformation measures are put forward when built fire pool is used as storage tank,and the simulation is carried out.The cold storage performance of the connecting system with multi slots is better than conventional system,and the additional hole plate can greatly optimize the performance of the system.The combination of the two transformation can greatly improve the performance of tank.