Study On Thermal Performance Of Phase Change Thermal Storage Building With Hot Air Heating

Phase change heat storage technology has become a research hotspot because it can solve the contradiction between building energy use and energy supply in time and space when using renewable energy as heating source.As an energy-saving envelope structure,phase change material wall can reduce the heat loss of the wall,thus improve the indoor thermal comfortableness.In this study,a phase change thermal storage plate was proposed,which was placed in the inner side of the wall to construct hot air assisted phase change thermal storage system.A demonstration room was built in Chongqing to measure the transient thermal characteristics of the phase change thermal storage system in the early winter and coldest months,which were compared with that of ordinary room.The hot-air phase change heat storage building stores heat during the day and releases it at night to increase the indoor temperature.The results indicate that,when the air inlet peak temperature of the phase change plate inlet header is higher than 55?,the thermal storage system can increase the indoor average temperature by 4.0⁵.5? in the daytime and 3.7⁴.4? at night,thus improve the thermal comfortableness.A one-dimension apparent specific heat capacity phase change thermal transfer model was set up and compiled to phase change wall thermal transfer type?Type205?in TRNSYS.The phase change storage building model in TRNSYS provides a calculation tool for thermal modeling of thermal storage building and prediction of indoor temperature.The model was validated by experiment data,which shows that the heat storage building model can better simulate the dynamic thermal properties of two rooms.Using the validated model to simulate indoor temperature changes during the night heat storage of the room,and to compare the effects of heat storage during the day on indoor temperature.Based on the proven hot-air phase-change heat storage model,the solar air collector was used as a heat source,a typical hot-air solar phase change thermal storage building in Tibet was designed by the solar air collector used as heat source.The temperature difference between the air inlet and outlet of the collector was calculated using the TRNSYS air collector module and the theoretical calculations.The results show that the TRNSYS air collector module can be used to simulate the solar collector air outlet temperature.Simulation of Lhasa hot-air solar thermal storage buildings,using the daily average daily temperature??? and daily heat release temperature offset ratio H_sr said heating effect.It was found that when the phase change material temperature is17²1?,the area of the phase change heat storage plate accounts for 50%of the wall area and is placed on the inside of the same wall,the heat storage effect is the best.At this time,the daily average indoor temperature of the phase change room is 4.2? higher than the ordinary room,which explained the feasibility of promoting the solar hot-air phase change thermal storage system as a supplemental heating for passive solar houses in Tibet.