Study On Dehumidification And Regeneration Performance Of Internal Cooling Solid Desiccant Bed Regenerated By Waste Heat Of Cabinet

In the 21st century,Solid desiccant air conditioning(SDAC)is favored by many researchers because of its advantages of environmental friendliness,low cost and low-grade heat source.In order to solve the problem that the solid desiccant release adsorption heat during adsorption and dehumidification,which results in reduced dehumidification performance,and enhance their competitiveness in energy saving.In the thesis,An internal cooling solid dehumidification device that uses the waste heat of the data center cabinet for regeneration was proposed.In the process of adsorption and dehumidification,cold water is introduced into the heat exchanger to cool the air.The cooled air flows through the dehumidification modules at all levels to exchange heat with silica gel,so as to reduce the impact of silica gel adsorption heat.The desorption and regeneration of dehumidification materials are carried out by using the waste heat of the data center cabinet,and hot water is pumped into the heat exchanger for auxiliary regeneration,so as to improve the desorption capability of the device.In this study,the performance indexes and influencing factors of the internal cooling solid dehumidifier are tested,and the calculation model of dehumidification and regeneration process is established.The theoretical value and experimental value are compared to verify the reliability of the experimental value.The research results of this article are as follows:(1)In a wide range of temperature(22?35?)and humid climate(65?75%RH),the range of dehumidification capacity of air is 5.51-19.53 g/kg,the range of dehumidification efficiency is 51.4%?73.9%,the range of silica gel moisture absorption is 29.2%?37.3%,and the range of silica gel utilization is 0.55?0.99.(2)Compared with the non-internal cooling condition,when the difference between the temperature of the cold water in the heat exchanger and the temperature of the inlet air is 2?6?,the maximum dehumidification efficiency of the inlet and outlet air can be increased by 43.8%,the maximum moisture absorption rate of silica gel can be increased by 22.7%,the maximum utilization rate of silica gel can be increased by 80%,and the minimum average temperature of silica gel can be decreased by 6.2?.(3)Under the condition that the temperature range of regenerative hot water is 60??80?,the dry base moisture content of the solid desiccant decreases with the increase of the regeneration water temperature,the minimum value is 0.8%;The regeneration rate is positively correlated with the regeneration water temperature,the maximum value is 4.6g/(kg·min),and the maximum average regeneration rate is 2.3%.The regeneration degree increases with the increase of the water temperature,the maximum regeneration degree is96.8%,and the maximum average regeneration degree is 85.6%.(4)The distribution of modules at different positions in the device results in different times of heat exchange between the air flowing through the modules and the heat exchanger,which results in the difference of dehumidification and regeneration effects between modules.In the process of dehumidification,the order of dehumidification effect of modules at all levels under the condition of Non-internal cooling is:first level,second level,third level,fourth level and fifth level;Under the condition of internal cooling,the order of dehumidification is:first level,fifth level,third level,second level and fourth level.The results show that the increase rate of silica gel utilization from the first stage to the fifth stage is 2.5%,6.1%,40.1%,64.3%and 103%respectively.In the process of regeneration,the order of regeneration is:the first level,the fifth level,the third level,the fourth level and the second level.(5)Based on the two basic principles of energy conservation and mass conservation,the calculation model of dehumidification process is established.Through the fitting tool,the judgment coefficient R~2 of the mass conservation model is higher than 0.95,and the average relative error between the theoretical value of the energy conservation model and the experimental value is less than 5%,which verifies the reliability of the calculation model.Combined with the existing semi-empirical model and experimental test data,the calculation model suitable for the regeneration process of solid dehumidification device is fitted.The judgment coefficient R~2 of the model is higher than 0.99,and the average relative error is12.06%.In the thesis,a renewable energy application system was proposed,which is driven by the waste heat of the cabinet to regenerate the solid desiccant bed,taken the average temperature and humidity of Hainan Island in summer and winter published in recent ten years as the test condition of this experiment,provides a new possibility for the design of dehumidification system in tropical island areas lacking conventional energy.It can be used as a theoretical reference for the design of dehumidification system in such areas and contribute to the sustainable development of the global environment.