Numerical Analysis On Energy Consumption Of A Small Building Based On The Wall Implanted With Heat Pipes

Wall, as the basic structure of building, is a key factor of energy consumption of buildings. The wall implanted with heat pipes(WIHP) is a new type of passive solar energy utilization technology, using the high efficient heat transfer performance, one-way thermal conductivity of gravity heat pipes and the temperature difference between the inner and outer surfaces of the WIHP, to achieve the heat transfer performance of the WIHP can be adjustable according to the requirement, so as to effectively reduce the energy consumption and improve the indoor thermal environment.In this paper, the heat transfer progress of the WIHP was theoretically analyzed. Then, the heat transfer performance under different outside surface temperature was investigated theoretically and experimentally. A small building energy consumption based on the WIHP was numerically studied by using TRNSYS to analyze the heat transfer capacity and energy saving rate of the WIHP. Moreover, the heat transfer performance of the WIHP is optimized theoretically and numerically through discussing the influence of the diameter, evaporation length ratio and filling ratio of heat pipes on the heat transfer performance of the WIHP. Finally, the applicability of the south and west WIHP in winter were studied through the theoretical calculation and analysis.The results indicate that the WIHP has good heat transfer performance, and the heat transfer performance is adjustable and controllable. The equivalent heat transfer coefficient of the WIHP increases gradually with the increasing of the outside surface temperature. Applying the WIHP to the building can obviously reduce building energy consumption, compared with ordinary buildings, the energy saving rate can reach 2.94% in Tianjin region, and the indoor thermal environment, especially in the transition season, is apparently improved. Moreover, the heat transfer performance of the WIHP increases with the increasing of heat pipes diameter, so the WIHP should choose larger diameter heat pipes under the condition of the wall structure permit. The optimal range of evaporation length ratio and filling ratio of the heat pipes implanted in the WIHP are 75%-80% and 30%-40% respectively.The results also show that the south WIHP is with more working hours, larger heat transfer capacity and higher energy saving rate. The working time of the west WIHP is postponed compared with the south WIHP, so the west WIHP can only be used in specific districts. Besides, combining the west and south WIHPs can suggest better performances, which can be popularized in engineering applications.