Experimental Study On The Thermal Performance Of Passive Solar Building Heavy Heat Storage System

In the current context of the global energy and environmental crisis, solar energy, as the most important primary energy among the renewable energy, will play a pivotal role in China’s energy development strategy. The area of severe cold and cold regions accounts for more than2/3of the total land area in our country. And the coal-based building heating produces vast quantities of greenhouse gas emissions and brings about serious environmental pollution. Therefore, solar heating technology has great significance to achieve the sustainable development of cities.Solar energy has the advantage of wide availability, cleanness and non-pollution. But solar thermal utilization is characterized by low energy density, intermittence and non-stability of solar radiatioa The thermal performance of solar building is instable, which causes great fluctuations in interior temperature of solar building.Thus, it results in lower efficiency of the stability of the solar heating system, the client comfort and energy utilizatioa Efficient heat storage technology is considered as an important means to overcome intermittent solar thermal instability and a core technology to improve the efficiency of solar energy utilizatioa The thesis gives a series of study on such urgent problems in the system of solar thermal storage technology of our country as thermal storage form, thermal storage design load calculations, thermal storage system energy transmission and distribution, and the impact of thermal storage on building environment and heat load.Firstly, the heavy solar thermal storage experimental system is constructed, namely a solar thermal storage heating system composed by ceilings, walls and other building components through the use of economical heavy material with a certain heat storage capacity, combined with solar air collectors, heat pipes, fans and controlled device. The heavy building solar thermal storage system can achieve three kinds of energy distribution of the direct experimental heating, heat storage and heating-heat storage conditions and were measured in heating season of DalianSecondly, the variation trend of heat storage coupling temperature boundary conditions is analyzed based on the measured results of heavy solar thermal storage system architecture, including the variation trend of thermal convection boundary conditions, the effect of thermal radiation boundary conditions and volatility of thermal convection-radiation on thermal boundary conditions coupled heat storage, and the influence of air flow pattern on indoor thermal environment. Thirdly, a study is given to the heat transfer process of the heavy heat storage, including the thermal performance and its problems of external air heating collector heavy wall, the decay depth and delay time of the ceiling temperature, and the matching attribute of the heat intensity and the heat transfer’s time.Then, an analysis is given to the mechanism of thermal effect on interior space, including positive and negative effect of reservoir of heat on the indoor space, the influence of heat storage on the thermal stability of the indoor space, the thermal effect between indoor air and its envelope, the relationship between the wind velocity and the.temperature change of other constructional elements, and significant factors of the indoor temperature under the effect of heat storage based on regression analysis.Finally, a temperature wave equation of thermal storage ceiling is formed, the impact of heavy thermal storage on the average building load and the guaranteed solar rate is analyzed, and the energy distribution of heavy thermal storage system in the solar architecture is drawn.The main conclusions of this study include:(1) The pattern of energy transfer in thermal storage ceiling is mainly realized through heat absorption by convection and heat release by radiation and the ration of heat transfer in convection and radiation is roughly7:3;(2) Under the conditions of heat storage and heating-heat storage conditions,the decay temperature in the thickness direction is38℃/m, in the longitudinal direction is only0.9℃/m;(3) Three significant factors that affect the interior space temperature in the heavy thermal storage system are respectively solar irradiance, the outdoor temperature and the wall temperature under the effect of the heat storage ceiling;(4) In three working conditions, assurance rate of solar heating can all meet standard requirements that up to10%-30%. Heat storage conditions at10:00-47:00, while heating-heat storage conditions at10:00-8:00next day were both higher than30%.