Simulation Research On Solar Hot Air Heating System Based On Heat Accumulation Of Inner Enclosure Structure

The solar hot air heating system that utilizes the built-in building envelope structure to store heat has advantages such as the use of clean energy,simple structure,and the advantages of building integration,in the cold winter application,the indoor air temperature can be effectively increased in northern civil buildings,which is of great significance for energy saving and consumption reduction,and thus has a broad application prospect.Since the enclosing structure has a certain degree of thermal inertia,enclosing structures with different structures and different thicknesses are used as the regenerators,and the heat storage capacity is different from each other.This topic focuses on the numerical simulation of a solar hot air heating system using internal walls or floors as a heat storage body,which is currently underresearched,to study the heat storage and release characteristics of the internal containment structure.The composition and working principle of the solar hot air heating system based on the internal enclosure structure heat storage were introduced,the physical model and mathematical model of the system were established,the grid division and boundary conditions were set up to lay the foundation for numerical simulation.In order to study the effect of wall structure and size on the heat storage effect,the heat storage and release process of interior walls under different thicknesses,different cross-sectional dimensions and different air distribution methods was simulated,the results show that: the smaller the wall thickness of the system during the day,the indoor temperature is higher,but the night temperature drops faster,the choice of channel wall thickness of 30mm~50mm on one side of the wall can maintain indoor all-day temperature maintained at 11 ℃ above;the solar hot air heating system that uses the internal wall for heat storage mainly relies on the surface wall for heat storage,changes the channel section length,the indoor temperature difference is within 1℃,changes the channel section width,and the daytime indoor temperature difference is about 1.5℃;the type of system for entering the air in the middle of the wall is about 1.5℃ higher than the system of the air inlet at the end of the day,and the temperature difference at night is within 1℃.In order to study the influence of floor structure and size on heat storage effect,simulations were conducted on rooms with different passage cross-sectional areas,spacings and structures,the results show that the average temperature of the indoor air in the channel with a channel side length of 140 mm is 4℃ higher than the system with a channel side length of 50 mm,and the night temperature is within 1℃;300mm floor spacing allows room to reach better temperature levels throughout the day;the nighttime room temperature of a system with a width of 1100 mm and a series arrangement of channels is about 7℃ higher than that of a system with a channel spacing of 140 mm and a parallel arrangement.