Numerical Study On The Solar Trans-seasonal Heat Storage In A Water Tank

There is a contradiction between the growing human demand for energy and the declining of existing energy resources.Energy consumption has now become a standard for measuring people’s living standards.The use of coal,oil,and natural gas has enabled the rapid development of human society.But these non-renewable energy reserves are limited,and contemporary society has begun to show signs of an "energy crisis." Faced with the dilemma of the energy crisis,mankind has launched a series of energy innovation revolutions,and the widespread application of new energy and storage of new energy have become research hotpots in recent years.The use of renewable energy by mankind has begun to become a new driving force for the development of human society.This article focuses on the solar cross-season heat storage system.The water buried in the underground water tank is used as the sensible heat storage material.Using CFD software,a coupled heat transfer model of the water tank and the soil surrounding the water tank is established.A user-defined function(UDF)was used.Numerical simulations of the unsteady natural convection heat transfer in hot water storage tanks at different inclination angles,soil type,depth of water tank,thickness of insulation layer,the monthly average temperature of the water tank during a heat storage quarter and its changing laws.Through research and analysis,the relationship between the strength of natural convection in the water tank and the inclination of the water tank was found,and the optimal inclination of the funnel-shaped hot water storage tank was established;it was found that the heat storage capacity of the water tank is greatly affected by the type of soil at the buried water tank.The effect of the depth of the water tank is also related to the type of soil.Finally,the heat stored in a hot water storage tank during a quarter of storage is calculated,and the stored heat can provide a five-storey dormitory building with a construction area of nearly 5000m2 for 50(hanging heating)or 80 days(floor heating).It was found that in the process of extracting heat,most of the heat comes from hot water,and a small part comes from the heat obtained by the reverse heat of the soil around the water tank.