Study On The Effect Of Absortents On The Performance Of The Absorption Air-conditioning System Based On Capacitive Deionization Regeneration Method

Under the social background of developing energy conservation,emission reduction and renewable energy utilization,building energy conservation has become increasingly important as a part of people’s daily lives.In building energy saving,the most important part is the energy saving of air conditioning systems.The traditional vapor compression refrigeration system has a high demand for electricity,and commonly used refrigerants such as Freon have a great damaging effect on the ozone layer.The emerging alternative refrigerants cannot completely avoid the damaging effects on the ozone layer,and the system performance also needs to be improved.Absorption air-conditioning system is a kind of green environmental protection air-conditioning system.Using water as the refrigerant has no damaging effect on the environment.At the same time,the requirements for electricity are not high.It can be driven by waste heat and solar energy.The system has good development prospects.However,the performance of the system is inferior to that of the vapor compression system,which greatly limits the development of absorption air-conditioning systems.In order to improve the performance of the system,a capacitive deionization（CDI）regeneration method is used in the absorption air conditioning system.Previous studies have only theoretically analyzed the performance of Li Cl solutions used in the system,lacking verification of the actual performance of the system,and targeting only a single type of absorbent.Therefore,based on this,the performance of different solutions and mixed solutions in the system is analyzed.In the theoretical research part,by establishing the system’s mass-energy balance model,theoretical COP and economics of different solution systems are calculated and compared.The analysis of single solution system found that the corresponding cost of a high-performance absorbent solution is also high.Therefore,the concept of mixed solution absorbents was proposed,and the absorbent solution was combined in pairs to establish a mass-energy balance model for the mixed solution system.Performance and economics of the system were analyzed.At the same time,one of the advantages of the capacitor deionization method is that it has energy storage characteristics.Reasonably reusing this part of the energy is conducive to improving system performance.The effect of different energy recovery efficiency on system performance is analyzed,and an energy recovery scheme is constructed.In the experimental research section,experimental system was set up.The performance and economics of the single solution of different concentrations and the mixed solution of different concentration ratios in the system were verified.At the same time,the actual energy recovery efficiency of the CDI unit was tested.The results show that the capacitor deionization regeneration method has a good treatment effect on the four solutions of LiBr,Li Cl,Ca Cl₂ and Mg Cl₂,and the corresponding system performance is also better than the traditional absorption air-conditioning system.Different solutions have different salt regeneration capabilities.The performance of LiBr solution is the best.When the concentration is 40%,the COP can reach 2.56.Economically,due to the high initial investment of LiBr solution,the total cost of short-term operation is the highest,but the total cost of long-term operation is the lowest.The research results of the mixed solution show that the LiBr+Ca Cl₂ system has the best performance.At a certain concentration ratio,the performance is better than the single solution system,and the cost of the system is also lower than that of the single solution system.At the same time,energy recovery efficiency has a significant impact on system performance.When the energy recovery efficiency is 50%,the system performance can be doubled.Making full use of the energy storage characteristics of the system is beneficial to further improve the system performance.Therefore,the capacitor desorption and regeneration regeneration refrigeration system has good development and application prospects.