Research On Dehumidification Performance Of The Metal Packing Absorbing Typed Dehumidifier Used In Air-conditioning

Refrigeration and air conditioning consumes large share of electric energy especially in hot humid areas. In order to overcome the latent load, the air is dehumidified achieved by bring the air temperature below its dew point temperature. The metal pack absorbing typed dehumidifier in this paper has several advantages as following: pollution free liquid desiccants, low operating noise, elimination of pollutants, improvement of air quality in the room, and high dehumidification efficiency. On the basis of its good environmental protection and energy-conserving characteristic, absorbing typed dehumidifier has very strong development and application prospect.Dehumidification performance of the metal packing absorbing typed dehumidifier used in air-conditioning is studied with experimental and numerical method in this paper. Metal packing absorbing typed dehumidifier experimental system is set up and tested. The effects of inlet parameters(air temperature,air humidity,air flow rate and solution temperature,solution concentration,solution flow rate) on the outlet parameters were also investigated. And a great deal of data collected through experiment was processed using multiple linear regression method. Several empirical formulas were given on coefficient of heat transferαC, Coefficient of mass transferαD. Mathematical model of dehumidifier describing heat and mass transfer between air and liquid desiccants is set up based on double-films theory. Taking the heat and mass transfer coefficients achieved from experiments as the input parameter of the model,the temperature distribution of air and water flow on the packing surface was described.It was found that for the fixed dimension, an increase in inlet air humidity ratio, air mass rate and inlet solution temperature results in an increase in air humidity ratio at the exit of dehumidifier. The exit temperature of air also increases with an increase in air mass flow rate, inlet air humidity ratio, inlet air temperature, concentration of solution and inlet solution temperature. However the air exit temperature decreases with an increase in solution mass flow rate. From the experimental result and numerical simulation result, we can draw the conclusion that the inlet parameters of the solution have more influence to heat and mass transfer performance. In the range from 0.4 to 0.96 of air to solution mass flow rate ratio,the dehumidification efficiency calculated is between 40%～87%. At inlet air temperature, humidity and air flow rate of 34.9℃, 25.92g/kgDA and 1.2kg/m2s, and inlet solution temperature, concentration and solution flow rate of 30.4℃, 20% and 2.58 kg/m2s, and air to solution mass flow rate ratio of 0.46, the maximum of dehumidification efficiency reached 87%. The dehumidifier runs steadily within experiment. Consequently, the feasibility efficiency of this dehumidifier can be obtained in application, which will force the subject studying forward. Moreover, the conclusions in this paper will be of some value for the later reference, such as the studying methods, the data, and the changing tendency of performance parameters.