Application Research On Passive Solar Building With Phase Change Wallboard In Shenyang Area

With the rapid development of economy and society, the demand on energy increases rapidly. There are lots of greenhouse gas emissions with a large number of fossil energy consumption. Energy shortage and resulting pollution have become an important restriction on sustainable development of economy and society of China. Therefore, reducing energy consumption, developing low carbon technology, and promoting the application of renewable energy have become an important direction for future development in China.At present, building energy consumption accounts for about 30% of the total energy consumption in our society, and building energy saving has become one of the important tasks to save energy and reduce emission. The use of solar energy, one of the inexhaustible energy resources, will save a lot of secondary energy consumption. During the process of design, construction and running of passive solar buildings, elements are added to adapt to the supply of solar energy so that the demand on building energy consumption is satisfied without consumption of other energy. At present, regenerative collector walls are generally used in passive solar buildings. In order to achieve the purpose of raising the temperature in the room, the vertical south regenerative collector wall is used to absorb the sunshine through the glass surface, and the heat is transported to the interior by conduction, radiation and convection. In the daytime in winter, the surface temperature of thick collector wall rises slowly; the air is heat up with relative large time delay; heat is transferred to the air indoor and outdoor from the collector wall with high temperature, resulting in a great heat loss. In the daytime in summer, the air is easy to be overheated because of the high surface temperature of collector wall.Phase-change material absorbs or releases vast energy during the process of phase changing. Energy can be saved or loads can be transferred if phase-change materials are used in building materials of other building products. In this thesis, phase-change material applying to phase-change wall is selected with preference and configured. The thermophysical properties of the selected phase-change material are tested and analysed.In view of the problems mentioned above, a combination of passive solar building and phase change wall is proposed. One of the characteristics of phase change materials is that the latent heat of phase changing is large. In the daytime in winter, solar energy is stored in the building envelopes, and then the saved heat energy is gradually released into the air in the night. In this way, the temperature fluctuation between day and night is reduced and thermal comfort is improved. In summer, the refrigeration ability saved from the outdoor air with low temperature in the night is used to reduce the temperature of the air indoor in the daytime. A passive solar house combined with phase change wall is established for experiments in Shenyang. The temperature of the air between the solar wall and phase change wall, the temperature of the air indoor, the temperature of the inner surfaces of the solar wall and phase change wall and the surface temperature of building envelopes are measured under the operation conditions of winter storage and heating, and summer storage and cooling. The thermal performance of the building envelopes is analysed. The partial correlation analysis method is used to analyze the weight of the affect of various factors on the temperature of the air indoor.Based on the dynamic heat capacity and thermal resistance network analysis method, a mathematical model of passive solar buildings combined with phase change wall is established. In this model, the unsteady conduction, the comprehensive role of phase change wall to the radiation and convection, the solar radiation and the radiation between the envelope surfaces are taken into consideration. Based on the heat balance analysis and the theory of exponential equation, the air temperature at various nodes in the system is calculated. The experimental test data is in good agreement with the simulation results, which proves that the model is correct.Using the verified mathematical model, a further analysis on the factors affecting the performance of the passive solar buildings combined with phase change wall and the optimization of architectural design is carried out. The simulation results show that the increase of interlayer thickness will raise the temperature of the air indoor, while it may also increase the possibility that the air indoor coming back to the interlayer. 0.4m is proved to be appropriate interlayer thickness. Compared the climatic conditions in Shenyang with those in other northern cities, the passive solar buildings combined with phase change wall have a wide application prospect in northern China.