| With the continuous increase of building energy consumption in the proportion of terminal energy consumption and the improvement of people’s awareness of energy saving,the use of renewable energy to reduce building ventilation energy consumption has become a hot spot in building energy saving research at home and abroad.The building solar chimney absorbs solar radiation through heat-absorbing materials,heats the air in its passage,and drives the air flow under the action of thermal buoyancy.It is an effective use of renewable energy to achieve natural building ventilation technology.At present,the research on building solar chimney mainly focuses on the influence of structural parameters and environmental parameters on its ventilation performance.However,there are few reports on the coupling effect of solar chimney effect and indoor heat plume.However,in actual situations,there are often heat sources inside buildings,and indoor high-temperature heat sources have a greater impact on indoor airflow and ventilation due to convection and radiation.In view of this,this paper establishes a three-dimensional mathematical model of multi-physical coupling of the solar chimney and the heat plume in the building,and uses three-dimensional numerical simulation to study the solar radiation intensity I,the heat flux density of the internal heat source W,the height of the internal heat source from the ground Z,and the surface of the internal heat source.The emissivity ε and the distance between the upper and lower air inlets of the dual air inlet chimney S and other factors affect the ventilation performance of the solar chimney;obtain the indoor local flow field,temperature field and pressure field distribution characteristics under the coupling effect;give the solar chimney ventilation Q and the sun The correlation formula of the coupling effect between the radiation intensity I and the surface heat flux density W of the internal heat source;reveals the coupling mechanism of the solar chimney effect and the heat plume of the indoor heat source.Mainly as follows:(1)Within the scope of this paper,the heat flux density of the internal heat source and the solar radiation intensity both have a gain effect on the ventilation performance of the solar chimney,and the two promote each other.With the increase of solar radiation intensity,the ventilation of the chimney gradually increases,the maximum increase is 22.3%,but the increase will decrease with the increase of the heat flux density of the internal heat source and the height from the ground.(2)With the increase of the heat flux density of the internal heat source,the chimney ventilation will increase under different solar radiation intensities,with a maximum increase of 23.3%.When the solar radiation intensity is small,the change of the internal heat source heat flux has a greater impact on the chimney ventilation,and with the increase of the height of the internal heat source from the ground,the heat flux of the internal heat source has a more obvious gain effect on the chimney ventilation.(3)The ventilation volume of the solar chimney gradually increases with the increase of the height of the internal heat source from the ground and the surface emissivity of the internal heat source,but the degree of influence is less than the intensity of solar radiation and the heat flux density of the internal heat source.In the case of a certain solar radiation intensity,the stronger the surface heat flux density of the internal heat source,the more obvious the gain effect of the internal heat source surface emissivity ε on ventilation.(4)The ventilation volume of the dual air inlet solar chimney will gradually increase as the distance between the upper and lower air inlets of the chimney increases.When the distance S between the upper and lower air inlets of the chimney is 1100 mm,the air movement direction of the air inside the chimney channel changes at the entrance of the chimney adjacent to the inclined section,and part of the airflow is disturbed with the air outflow from the upper air inlet of the chimney,causing the upper air inlet of the chimney to enter the chimney The air flow rate of the channel is greatly reduced,and the total flow rate and the outlet wind speed of the chimney outlet are reduced.(5)The exit wind speed of the solar chimney is positively correlated with factors such as solar radiation intensity I,internal heat source heat flow density W,height Z from the internal heat source to the ground,surface emissivity of the internal heat source ε,and the distance between the upper and lower air inlets of the chimney S. |
