Experimental Study On Performance Of Solid Desiccant Bed Regenerated By Microwave And Cabinet Exhaust

As a large energy consumer,data center’s energy consumption is mainly composed of IT equipment energy consumption,refrigeration system energy consumption and power consumption,among which refrigeration system energy consumption accounts for about40%.On the premise of meeting the normal operation of the equipment,reducing the energy consumption of the refrigeration system is of great significance to the construction of a low energy consumption data center.The traditional control mode of temperature and humidity coupling in air conditioning system has the problem of energy waste.The application of temperature and humidity independent control air conditioning system in the cooling system of data center can effectively reduce the energy consumption of data center by using humidity control system to eliminate outdoor fresh air residual humidity.In the dehumidification system,regeneration energy consumption accounts for most of the energy consumption of the whole system,which becomes one of the main factors restricting the development of temperature and humidity independent control air conditioning system.According to the characteristics of high efficiency and energy saving of microwave,high regeneration rate,and the characteristics of data center exhaust air with almost no latent heat load,large heat dissipation capacity of equipment,and long heat dissipation time,this paper proposes a solid dehumidification bed system with microwave and cabinet exhaust coupled regeneration.Under the dehumidification condition,the maximum dehumidification capacity and average dehumidification capacity are 15.59g/kg and 3.59g/kg,respectively,and both occur in the high temperature and high humidity condition(33℃,80%RH).Under the same test conditions,the higher the inlet air temperature is,the higher the maximum and average dehumidification capacity of the dehumidification bed are;the higher the relative humidity of the inlet air is,the higher the maximum and average dehumidification capacity of the dehumidification bed are.Reducing the relative humidity or temperature of the inlet air can effectively prolong the effective dehumidification time of the solid desiccant bed.The moisture absorption of silica gel is directly proportional to the relative humidity and inversely proportional to the temperature.The highest moisture absorption rate was in Guangzhou summer(28℃,80%RH).In the regeneration process,the regeneration degree of microwave and hot air coupling can reach 100%under all conditions.When the regeneration degree is 100%,the unit energy consumption is the highest under the condition of hot air 40℃and microwave power 500W,which is 0.367(k W·h)/kg;The unit energy consumption is the lowest,which is0.266(k W·h)/kg.The higher the microwave power is,the higher the average energy utilization rate is,the faster the change rate of dry basis moisture content is,the shorter the time to reach the dry basis moisture content tends to zero,and the greater the impact on dry basis moisture content is.Compared with single hot air regeneration,microwave hot air coupled regeneration has higher regeneration efficiency.In practical engineering application,single cabinet exhaust regeneration has lower unit energy consumption and higher energy utilization rate than microwave and cabinet exhaust coupled regeneration.The optimal conditions of regeneration efficiency are 50℃exhaust temperature,700W microwave power and 0.5m/s wind speed;The working condition with the lowest energy consumption and the highest utilization rate is that the exhaust temperature of a single cabinet is 50℃and 0.5m/s wind speed.Based on the experimental test,the dehumidification and regeneration model of dehumidifier is established.The average correlation coefficient R~2 is 0.9982,and the average relative error is 2.56%.By comparing the correlation coefficient R~2 of five commonly used regeneration empirical models,it is found that the correlation coefficient R~2 of midilli model is the highest,and the average correlation coefficient reaches 0.9995.The experimental values and model values of various regeneration conditions are compared,and the average relative error is-0.6%.The dehumidification and regeneration models established in this paper have good accuracy and reliability.