Study On Application Of Solar-air Source Heat Pump Capillary Radiant Heating System In Beijing

In recent years,"haze days"has become a"new normal"in Beijing,which constantly endangering people’s health.Extensive Coal-burning for heating is one of the major causes of haze in the north.Utilizing clean energy heating to adjust the traditional energy structure is one of the directions to improve the environment in Beijing.At present,the system that combined solar energy and air-source heat pump is commonly applied in hot water supply,which most research studied on.Nevertheless,this system was also able to replace the coal-burning heating.This paper established an experiment of solar-air source heat pump capillary radiation heating system to study the system feasibility of low-story office buildings in Beijing.The major study methods are presented as follows.（1）Exergy analysis is utilized in the heat transfer process in order to reveal the variation of the energy quality.The exergy balance equation is established to analyze energy quality variation,through which the system optimization strategy is put forward.By theoretical analysis,it is found that the exergy loss is related to the inlet water temperature（T_L）,the outlet water temperature（T_H）and the heating temperature（T_S）.The exergy loss could be reduced by adjusting water flow volume in the heating collecting process.On the other hand,in the process of heat releasing,the exergy loss is primarily caused by capillary radiation heating,related to the radiation area.（2）In order to verify the practical applicability of the system in Beijing,an experimental solar-air source heat pump capillary radiant heating system was set up.Three main heating modes（capillary radiation running mode,solar-air source heat pump mode,air-source heat pump mode）are studied.Through the comparison of indoor temperature and heating performance,the characteristics and applicability of three modes are obtained.The results show that solar energy utilization rate could be intensely improved by the union of two running modes,which are capillary radiation mode and solar-air source heat pump mode.（3）The economic and environmental analysis of solar-air source heat pump capillary radiant heating system in Beijing was carried out.Compared with the traditional air source heat pump,the solar-air source heat pump capillary radiant heating system can save 38.6kg of burning coal,which reduces the emission of CO₂by 96.2kg and SO₂ by 2.9kg.Therefore,the system has certain applicability in economic and environmental protection in Beijing.