Design And Simulation Of A Novel Liquid Desiccant Evaporative Cooling Air-conditioning System

Air-conditioners are more and more widely used in the social production and daily life as the development of society. At the same time, the conventional mechanical compression refrigeration system's two big problems have attracted the attentions of investigators. One of the main disadvantages of that system is that it uses very large amount of electrical energy and the other is that the system's working substance can pollute the environment. As the competitor and replacer of the conventional mechanical compression refrigeration system, the liquid desiccant air-conditioning system is energy saving and harmless for the environment. It can be driven by low grade energies, such as waste heat and solar energy.In this work, a novel energy efficient air-conditioning system utilizing liquid desiccant is introduced, after the author sums up the previous researches. At first, fresh air from the atmosphere is dehumidified by direct contact with strong liquid desiccant in the dehumidifier; after being cooled by the evaporative cooling sub-system the process air is blown into the air-conditioning space. The dilute solution is re-concentrated in the regenerator by the effect of heat energy, so the strong liquid desiccant solution can be produced uninterruptedly.The paper presents the application of numerical simulation method to study the proposed liquid desiccant air-conditioning system. And this system is composed of several sub-units; each of them is simulated by the mathematical model for building computer programs. These programs are linked to form an integrated C program simulator. Based on the simulation of the liquid desiccant system, this paper applies the first and second law of thermodynamics to research the effects of five key parameters on the performances of the proposed system, such as the supply air temperature and humidity, the cooling capacity and COP, the exergy of cooling capacity and exergy efficiency. These parameters are the inlet solution temperature in regenerator, the air-to-dehydrated desiccant mass flow rate ratios in dehumidifier and regenerator, ambient air temperature and relative humidity.