Study On Solar Low Temperature Radiant Heating System

Under the background of vigorously advocating building energy conservation,the promotion of green and energy-saving heating methods has been widely mentioned,and many related green energy-saving heating experiments have continued.In order to improve the contribution rate of solar energy in building heating system,a new type of dual-heat source capillary low-temperature radiant heating system with flat-plate solar heat collection system as the main heat source,air source heat pump as auxiliary heat source and capillary network as the end device was designed.Compared to conventional heating systems,the system differs from the heat source and the heating end way in that it not only saves energy but also improves human comfort.At present,the application of solar energy as the main heat source in the life of the application is still few,in this paper,the theoretical analysis and experimental research methods are used to study the solar energy contribution,energy saving and heating characteristics of the dual-heat source capillary low-temperature radiant heating system,and provide examples for the application of solar energy in the winter low-temperature radiant heating system.First of all,using De ST to simulate the energy consumption during heating of a villa of a building with a building area of 50.6m2 in the Wuhu area,and to obtain the correlation between the hourly cooling load,the heating and air conditioning heat index and the cumulative heat load during the heating period in winter.Secondly,a capillary radiant heating system was designed for the experimental building,and the capillary network was laid on the building's ground and walls.The total laying area was 100m2.The heat source side is an air source heat pump and solar composite heat source system,and introduces various components of the system.Subsequently,the contribution of solar energy on the heat source side of the capillary network heating system was studied,and the energy consumption of the heating system was analyzed.The results showed that the solar heating contribution rate reached 45%,42.5%,and 39.4% when the water temperature was 25,30,and 35 °C,respectively,when the solar irradiance was sufficient in winter(489.5~565.2 W/m2).“Capillary network with composite heat source” and “capillary network with air source heat pump” are compared and analyzed experimentally.When the water supply temperature is 25°C,30°C and 35°C respectively,the composite heat source scheme is opposite to the air source scheme.The electricity saving rate reached 21.3%,19.6% and 18.7% respectively.Finally,an experimental study of capillary network radiant heating system was conducted.The indoor comfort was analyzed from the indoor air temperature,the surface temperature distribution of the indoor enclosure,the temperature distribution of the radiant floor surface,and the change in the indoor relative humidity.It is concluded that the maximum temperature difference in the horizontal direction and the vertical temperature difference in the horizontal direction of the room are within the range of comfort standards.In addition,the indoor relative humidity is suitable and the relative humidity variation is small to meet the indoor air temperature comfort standard.