Numerical Simulation Of Solar Energy Storage In Trans-seasonal Soils

The improvement of people’s lives is premised on the production of high-quality energy and the use of efficient energy technologies.In other words,energy is the foundation of all human social activities.In recent years,the increasing energy depletion and air pollution problems have sounded alarms for mankind,and have prompted countries around the world to vigorously promote new energy sources.Solar energy,a new type of energy,has received increasing attention.As a new type of solar energy application,solar seasonal heat storage technology can reduce the limitation of time and greatly improve the efficiency of solar energy application.In view of this,this article first briefly introduces common solar crossseason heat storage methods,then,taking Beijing as an example,the soil is the thermal storage medium,using ANSYS FLUENT simulation software to establish a numerical model of the coupling heat transfer between a single horizontal buried pipe and soil,combined with the user-defined function(UDF)to realize the dynamic simulation of solar heat storage across seasons.The duration of the simulation calculation is the entire non-heating season(March 16 th to November 15th).Study the change law of soil heat storage with the calculation time during the whole calculation time.The results of the study show that the heat storage of the soil does not continue to increase with the increase of the heat storage time,but shows a change that first increases and then decreases with the increase of the heat storage time,and reaches a peak around August 15.In addition,in this paper,through the established numerical model of heat transfer between the buried pipe and the surrounding soil,under the same conditions of flow velocity,pipe diameter,soil initial temperature and calculation time,the effects of the depth of the buried pipe,the temperature of the fluid inlet in the pipe,the soil thermal properties and the distance between the buried pipes on the temperature distribution of the soil heat storage body are discussed.From the temperature distribution of the soil,the effect on the heat storage effect of the soil is further calculated.The results show that: For the three working conditions with burial depth of 1.5m,2.0m and 2.5m,the soil with a depth of 2.5m has the largest heat storage,and the soil with a depth of 1.5m has the smallest heat storage.For the three working conditions with fluid inlet temperature of 60 ℃,70 ℃ and 80 ℃,the soil with the inlet temperature of 80 ℃ has the largest heat storage capacity,and the soil with 60 ℃ has the smallest heat storage capacity.For the four soils of sand,clay,brown soil and granite,brown soil is the most conducive to heat storage,while sandy soil is the most unfavorable.For the four working conditions with the buried pipe spacing of 2.8m,3.2m,3.6m and 4m,the heat storage of soil increases with the distance between buried pipes,The soil with the buried pipe spacing of 4m has the largest heat storage,and the soil with the buried pipe spacing of 2.8m has the smallest heat storage.