Study On Direct Condensing Air Source Heat Pump Radiant Floor Heating System

Heating is the basic needs of the residents of the northern in winter, the energy consumption of heating accounted for nearly 30% of the country’s total energy consumption of building energy consumption. The current heating mainly includes, the air-conditioning system heat radiating piece of natural convection heating and radiant floor heating, which floor heating is considered to be the highest energy efficiency and thermal comfort. In recent years, floor heating grew rapidly in the north and in the middle and lower reaches of the Yangtze River. In the future building heating ways, more than 60% will be used radiant floor heating system according to the analysis of. Floor heating system has a comfortable high, energy-saving and health conditions, but the heat efficiency, environmental protection, reduce the transmission and distribution system energy consumption and reduce intermediate energy conversion loss of the conventional low temperature hot water floor radiant heating system should be improved in the future.New floor radiation heating system-direct condensation type air source heat pump heating system import the refrigerant into the floor coil pipe directly, instead of the conventional heat pump system of condenser, reducing the intermediate energy transmission links and thermal resistance, greatly reduces the energy consumption of the system, the related research just begin. This paper focuses on the basic theoretical and experimental research of the Direct condensing air source heat pump floor heating system, expect contribute the development of the Direct condensing air source heat pump floor heating system.In the first chapter, the research significance and domestic and foreign research status of the direct condensing air source heat pump radiant floor heating system were review and analysis, and this chapter also has been clear about the research purpose and content.The working principle and basic problems of the direct condensing air source heat pump radiant floor heating system have been carried on in the second chapter. The heat dissipating member of the direct condensing air source heat pump radiant floor heating system buried underground, and conventional heating system radiator directly dissipate heat to air, the other heat transfer modes and conditions also changed. At the same time, compared with the plumbing heating tube, the media is refrigerant instead of water. In order to define the effects on the performance of the system, direct condensation type air source heat pump heating system and air cooling system and water heating system heat transfer performance was compared. The underground pipe is very special and important part of the direct condensing air source heat pump radiant floor heating system. This paper analysed the working conditions and requirements of the direct condensing air source heat pump radiant floor heating system from the physical properties, heat transfer performance, processing, bearing capacity, economy and resistant corrosion. And it determined the selection of stainless steel tube as the coil pipe of the direct condensing air source heat pump radiant floor heating system.In the third chapter of this paper, ANSYS numerical simulation software was used to establish the heat transfer model of floor heating mechanism layer, and the influence factors of heat transfer in layer structure was also studied.Finally, the surface temperature and heat flux density of different condensing temperature, surface layer material, the thickness of the filled layer and the tube spacing were obtained, which provides guidance for the actual engineering construction.In the fourth chapter, the selection and design of the components of the direct condensing air source heat pump radiant floor heating system (DCHP air) have carried.The fifth chapter analyzes and arranges the experimental data. The experimental results was analysed mainly from energy efficiency and comfort parameters. The experimental data show that the when the outdoor temperature 00C, humidity is 50%, The hourly energy efficiency ratio can reach more than 2.72, when the outdoor temperature rise to 50c, unit hourly energy efficiency ratio increased to above 3.41, much higher than the other heating form. The direct condensing air source heat pump radiant floor heating system has the advantages of high heating comfort. Especially in the intermittent operation, the room temperature and surface temperature fluctuations slightly. Those also provide comfortable indoor thermal environment in accordance with standard of GB50736-2012.Finally, the full text is summarized, and the deficiencies of this study and future research are put forward.