Experimental Study On Air-source Heat Pump Combined Heating In Winter

With the development of the global economy in the 21 st century,energy crisis and environmental pollution have become the core problems that people pay close attention to.People urgently seek for energy-saving measures to solve these problems,the heating energy consumption has been in building energy consumption accounted for a large,air source heat pump technology to extract heat from the air,energy conservation,environmental protection,as a heat source in winter is a good choice.In areas with hot summer and cold winter,it is wet and cold in winter.Ordinary split air conditioners and electric heaters can no longer meet people’s needs for thermal comfort and energy saving.Radiative heating has better thermal comfort,but the thermal response time is longer.In this paper,through theoretical analysis combined with the measured,and the research under the different water supply temperature,radiation floor + fan coil units at the end of the room air source heat pump heating system and the running effect,thermal environment and radiation,respectively,and end use ceiling + fan coil units and fan coil heating,finally analyze the heating efficiency of the system,explore its applicability in chongqing area and the market prospect.First of all,the research results and development trend of radiative heating technology at home and abroad are investigated and analyzed,and the research content and technical route of this paper are put forward.Of air source heat pump and wallmounted gas furnace with radiant floor heating,respectively,when the economy were analyzed,at the same time use the chongqing regional climate characteristics and the software simulation research laboratory in university campus construction load characteristic,for the region based on air source heat pump radiant floor + fan coil heating system provides data support and theoretical basis.Secondly,the laboratory radiant heating system and air conditioning system were designed,and the distribution of indoor thermal and humidity environmental parameters,the change of heat pump power,the system energy efficiency and the hydraulic transmission and distribution under different temperatures of the air source heat pump water supply temperature at 35℃,37℃,39℃,41℃,43℃ and 45℃ were studied.The results show that when the system is running stably,the temperature difference between the human standing posture(1.7m)or sitting posture(1.1m)and the ankle(0.1m)is within the recommended 2℃.The higher the water supply temperature,the higher the floor surface temperature,only 41℃,43℃,45℃ water supply floor temperature meet the recommended value of 25℃～27℃;When the system is just started,the power of the unit rises rapidly and then decreases and tends to be stable.Both the power and the time required to reach s Tab.operation of the unit increase with the rise of water supply temperature.When the system is stable,the power is 1250W～2500W and the time required is 28min～60min respectively.During the s Tab.operation of the system,COP varies from 2.39 to 2.8 when the water is supplied at 35℃.At 37℃,COP varies from 2.28 to 2.69.At 39℃,COP varies from 2.26 to 2.63.COP varies from 2.16 to 2.58 at 41℃ water supply.When water supply is at 43℃,COP varies between 2.16 and 2.53.At 45℃,COP varies from 2.26 to 2.44.Then,when the water supply temperature is 45℃,the indoor thermal and wet environment,power,supply and return water temperature and energy efficiency of the radiated floor + fan coil unit,radiated ceiling + fan coil unit and fan coil unit heating at the end are experimented.The results show that the indoor vertical temperature gradient is small only when the end device is radiant floor + fan coil unit,and the temperature difference between the ankle and the standing or sitting posture is within the recommended 2℃.When the three are stable,the power is 2500 W,2500W and 1400 W respectively,and the required time is 60 min,76min and 28 min respectively.During the s Tab.operation of the system,when the end device is radiant floor + fan coil unit,COP varies between 2.26 and 2.44.When the end device is radiant ceiling + fan coil unit,COP varies between 2.23 and 2.41.When the end device is only fan coil unit,COP varies between 2.47 and 2.6.Finally,compared with the separate air-conditioning and gas wall-hanging furnace heating system,the results show that the air-source heat pump heating system has no obvious advantages in economy,but the indoor comfort is much better than the split airconditioning system.Compared with the gas wall-hanging furnace system,the investment is close,but the equipment service life is longer,environmental protection and low carbon.The research results of this paper have certain guiding significance and reference function for promoting heat pump heating and improving indoor environmental quality of residential buildings in hot summer and cold winter areas.