Heating Performance Of Solar House With Closed Air Loop Coupled TCM

Heating of solar house with closed air loop coupled TCM is that air warmed by solar air collector is driven by fan and construction six body inner surfaces are warmed by heat transport through the building envelope air loop, so uniform room radiant heating s is achieved, problems are ameliorated such as dry heat, uneven radiation discomfort and health caused by warm air heating. Temperature fluctuation of solar house was inhibited and nighttime heating was improved by thermal storage in building envelope.In this study, series of studies were carried out such as principle of heating and cooling, design of heating and cooling plan and architectural form, operation and control ways, automatic operation system, to built experiment platform, experimental study, theoretical analysis, simulation and verification, free running temperature prediction. Theoretical reference on building design, operation control and regional applicability of solar house with closed air loop coupled TCM were provided by these theoretical research resultsThe main research contents and results are as follows:First of all, passive solar heating and cooling solutions and architectural form of solar house with closed air loop coupled TCM were determined by the building climatic design in Dalian. According to the building heat demand, heat gain in winter and cooling summer were taken into account, warm air circulation and thickness of air layer and the heat storage material and layout were determined, etc. Based on these, full scale experiment room and reference room of solar house with closed air loop coupled TCM were built.Secondly, automatic operation of solar house with closed air loop coupled TCM heating all day was implemented with intelligent fan and dampers linkage control. Fans and dampers open automatically while temperature of collector outlet air higher than 22 "C, fans and dampers closed automatically while temperature of collector outlet air less than 18℃. Automatic starting with maximum speed, to ensure the 10～15℃ difference between collector inlet and outlet temperature by adjusting the fan speed. Instead of instantaneous value, the average value of solar irradiance was used to improve system stability; temperature sudden drop was avoided by fan opening lOmin delay; residual heat was utilized within the collector delayed by 10min dampers closed.Third, based on a large enough scale experimental platform, five experimental conditions were set by adjusting the solar air heating system, external roller blind, removable external insulation to the south window at night. Testing systems were used such as multi-channel itinerant detecting instrument, multi-channel temperature and heat flow logger, weather station and real-time data acquisition of solar air heating, to study solar air house with closed air loop about heating forms, heat storage systems, removable exterior insulation at night and indoor thermal environment characteristic. Studies shows that:1) Indoor air temperature in window directly benefit heating form reached 13℃(that is passive solar design heating room temperature limits) 50min in advance than solar air heating system. However, significant effective thermal storage of TCM in solar air heating system solar air collector heating form results in 180min delay to drop to the lower limit value than the benefited window heating; 2) Due to the heat storage system, night indoor and outdoor temperature difference is increased 6.5℃that indoor thermal stability was improved Significantly.3) 10% heat loss and 2.0℃ temperature difference between glass and wall was reduced by removable insulation of experimental house, then to weak the uneven radiation and improve indoor radiate comfortable at night in winter.4) The operating temperature of experimental room day slightly higher than or equal to the room air temperature under the form of solar air heating, due to lightweight structural houses.Finally, according to the flow process of the closed air cycling layer in the building envelopes around the building with solar air collectors was divided two situations, a heating period in the daytime and heat preservation at night. The heat transfer mathematical model of the heating period in the building with collector and windows has been established, based on the theory of the heat transfer in air layer and introduced the saturation coefficient of TCM. The simulation result of indoor air temperature, temperature and saturation coefficient of TCM phase change materials have been validated by experiment data, which could institute that the simulation value was consistent with the actually measured value. Using a heat storage and heat transfer model, and analyzing by the one dimensional prediction formula of construction heat gain and heat loss, natural operation temperature of different building thermal characteristics and different climatic conditions on the closed cycle the influence of air layer solar building indoor thermal environment have been analyzed. Prediction results show that thermal performance directly influences the indoor and outdoor temperature difference in the whole heating cycle, solar radiation directly influenced the daytime heat gain and heat storage and indirect heating at night, the outdoor temperature directly affects the indoor air temperature.