Experimental Study On Applicability Of Direct Expansion Air-source Heat Pump Radiative Panel Heating System In Chongqing

At present,the room with air source heat pump for heating has the problem of poor thermal comfort.In order to improve the current indoor heat environment using air source heat pump for heating,combined with the advantages of better radiant heating and heat comfort,a terminal is designed to use radiation.The panel-heating direct-expansion air source heat pump heating system,in which the radiator is used as a connection between the indoor end heat sink and the air source heat pump outdoor unit,is connected by copper tubes,and the suitability of the system for heating in Chongqing is experimentally studied.Combined with the meteorological characteristics and geographical features of Chongqing,five typical conditions were selected to conduct continuous heating experiments to study the applicability of direct-expansion air source heat pump radiant panel heating systems in Chongqing.Under different operating conditions,the system takes about 40 minutes from start-up to stable operation.Low temperature,rainy days,and low-temperature overcast,due to low outdoor temperature and high humidity,the unit will experience a large surge phenomenon after 20 minutes of starting operation.After a few minutes,the shock suddenly disappeared.The experimental data were used to study the variation of parameters such as unit power,surface temperature of the radiant panel,indoor air temperature at different heights,wall temperature,and other parameters over time.The experimental data were processed to obtain the rule of the COP value of the system under different working conditions.The system performs continuous heating experiments on a sunny day.The system COP value varies from 2.98 to 3.2.The system performs continuous heating experiments on a rainy day.The system COP value varies from 2.95 to 3.03.The system performs continuous heating experiments on a cloudy day.The system COP value Between 2.91 and 2.99,the system performs continuous heating experiments on low temperature and rainy days.The COP value of the system varies between 2.56 and 2.63.The system performs continuous heating experiments at low temperature and cloudy days.The system COP value varies between 2.58 and 2.62.In order to study the indoor thermal environment during continuous heating,the indoor radiation asymmetry values and vertical temperature gradients were calculated to be within a reasonable range through experimental data,and the comfort was good.Considering the system heat source and the type of the end heat sink,the split type air conditioner and the air source heat pump hot water floor heating system are selected for economic comparative analysis,and the cost year values of the three systems are respectively calculated.The direct expansion type air source heat pump radiation panel heating system and the sub-system The year-on-year cost of the air-conditioning system is relatively close,the annual value of the cost of the air-source heat pump hot water floor heating system is the largest,and the annual cost of the direct-expansion air-source heat pump radiation board heating system is the smallest.In this paper,continuous heating experiments are performed on the direct expansion air-source heat pump radiant panel heating system.The experimental data is processed to analyze the system performance and provide data support for the application of the system to the actual project.