A Study On The Performance Of Air Conditioning Systems Using Heat And Humidity Independent Treatment For Condensing Heat Classification

An air conditioning system with independent treatment of heat and humidity can overcome problems existing in traditional air conditioning systems, such as reheat loss, poor adaptability of enthalpy humidity ratio, low system energy efficiency, etc. It is a hot topic both domestic and international, but system performance in winter condition is seldom put in research.In this paper, a type of air conditioning system was introduced with independent treatment of heat and humidity in grade utilization of condensation heat. Through organic combination of solution circulation and vapor compression refrigeration cycle,with graded utilization of condensing waste heat, the problem of high solution recycling heat compensation in air conditioning system with independent treatment of heat and humidity was properly resolved, and energy efficiency could be improved. In summer condition, evaporation temperature was raised to realize dry operation, thus greatly increasing system COP. In winter, evaporator inlet air humidity was reduced with solution desiccant, thus restraining frost on evaporator surface. Also in winter condition, heat of outdoor wet air was fully used as the low temperature heat source of heat pump evaporator to improve energy efficiency, and supplying air was humidified in solution regeneration process to reduce energy consumption.Factors influencing the performance of solution regenerator, the pivotal equipment in air conditioning system with independent treatment of heat and humidity,were studied in this paper. An experimental platform was set up for a counter flow adiabatic regeneration process in graded utilization of condensation heat. An NTU-Le model of counter flow adiabatic dehumidifier or regenerator was built.Regenerator outlet parameters could be predicted in good agreement with experimental results.In utilization of the NTU-Le model of counter flow adiabatic dehumidifier or regenerator, influences of various methods for graded utilization of condensation heat on regeneration process performance were studied. Results showed that condensation heat was better used in heating solution than air, the former of which improved regeneration process performance and result better. An appropriate temperature of solution regeneration should be comprehensively selected to achieve better results of regeneration.A study on overall thermal performance of the system in winter condition was carried out, in which influences of climatic parameters and key operating parameters on system performance was analyzed. The influence of the outdoor air temperature,outdoor air humidity,indoor air return air temperature and the humidity on the system key operation parameters and the influence of the performance of the system was analyzed. The results show that the lateral indoors,air humidity is bigger than air temperature on the influence of the COP. In outdoor air temperature is greater than the effect of air humidity on the COP.Through experiments in wet and cold winter condition, this system was proved to have frost suppression characteristics. If working in the same evaporation temperature,this system can avoid frosting problems on evaporator surface. If working in frost free mode, this system can reach lower evaporation temperature than traditional air source heat pump. Accordingly, this system is particularly suitable to be promoted in wet and cold areas.