Performance Study Of Frost-free Air Source Heat Pump Driven Liquid Desiccant Dehumidification Temperature And Humidity Sub-control Air Conditioning System

With the development of society and economy,people have higher and higher requirements for the comfort and health of life.The development of HVAC has brought great comfort to people’s lives,but it has also brought problems such as high energy consumption and environmental pollution.Therefore,it is of great practical significance to develop energy-saving and environmental protection air-conditioning systems.Aiming at the shortcomings of the existing air-conditioning system,this paper proposes a frost-free air source heat pump-driven liquid desiccant dehumidification temperature and humidity sub-control air conditioning system.This system uses a liquid desiccant dehumidification system to handle indoor latent heat,Indoor sensible heat end treatment indoor sensible heat.Under summer operating conditions,Recovery of heat of condensation of heat pump during summer operation to heat regenerated solution and air.In winter,the outdoor air is dehumidified by the solution dehumidification system before entering the outdoor heat exchanger,which can avoid frosting on the surface heat exchanger,and at the same time use the solution regeneration process to humidify the fresh air sent into the room.This paper introduces the composition of the new system and the workflow in winter and summer in detail,establishes the mathematical model of each part of the system,connects the model of each part,draws the thermal calculation method of the system,and establishes the system calculation model by MATLAB software.For summer operating conditions: The temperature of the inlet of the dehumidifier solution,the concentration of the inlet of the dehumidifier solution,the ratio of the solution flow rate between the dehumidifier and the regenerator,the proportion of the condensation heat used by the solution heater,and the influence of the air flow rate of the dehumidifier inlet on the system performance are analyzed.When each influencing factor is 0.26,20 ℃,0.20,0.5,0.3kg/s,the system performance can reach the best.Under the Xi’an outdoor air-conditioning calculation parameters,the SCOP,HCOP,and EER values ? ? of the system are 4.5063,5.1131,and 4.1064,respectively.The system performance increases as the outdoor air temperature increases,and the outdoor air moisture content decreases.Under the same operating conditions,the system proposed in this article is compared with two conventional heat pump-driven solution dehumidification air conditioning systems that use condensing heat and no condensing heat.The results show that the COPR values ? ? of this system and the other two systems are 1.25~2,1.45~2.2,the system performance advantage is obvious,and under high temperature and high humidity conditions,the COPR value is greater.For winter conditions: when the solution flow ratio between the dehumidifier and the regenerator is0.08,the system performance is the best.Under the Xi’an outdoor air-conditioning calculation parameters,the system’s SCOP,HCOP,and EER values ? ? are 2.1951,2.3567,and 2.0732,respectively.In the winter frosting area,the dew point temperature of the air after dehumidification is lower than the dew point temperature before dehumidification by 4.29℃ to 5.29℃,which ensures that the dew point temperature of the air after dehumidification is lower than the evaporation temperature of the heat pump system,thereby avoiding frost formation of the air source heat pump.The change law of the system’s heat pump cycle performance coefficient HCOP value with outdoor air temperature is the same as that of a conventional air source heat pump system during normal operation,and increases with the increase of outdoor air dry bulb temperature,and the HCOP value is not affected by outdoor relative humidity.It shows that the system can run stably in winter frosty area.