Evaporative Cooling Cold Water System Based On Desiccant Wheel Driven By Low Temperature And Low Humidity

The rotary dehumidification air-conditioning system can realize independent control of temperature and humidity,so that the system can drive dehumidification by low-grade heat energy,and cool down by high-temperature cold source,which can well solve the energy waste,poor comfort,low dehumidification and mold growth,these caused by the combined heat and humidity treatment of the traditional cooling and dehumidification method.However,the high regeneration temperature,dehumidification temperature rise and heat loss make the traditional rotary dehumidification air-conditioning system inconvenient use for low-grade heat energy and high-temperature cold source,so the energy-saving advantage is difficult to reflect.In response to the above problems,the research in this paper is as follows:The pre-cooled rotor dehumidification air-conditioning system was studied experimentally.The results show that under the same working conditions,the pre-cooling measures are added to make the pre-cooling system have the refrigeration capacity,dehumidification capacity and thermal performance coefficient compared with the conventional rotor dehumidiflcation air conditioning system higher respectively is 144.4%,35.4%and 136.4%.Through thermodynamic theory analysis,comparative analysis of the application of pre-cooling,heat recovery and reducing the moisture content of regenerative air in the conventional rotor dehumidification air-conditioning system energy-saving effect,on this basis,proposed a low-temperature and low-humidity drive double-rotor dehumidification air-conditioning system,The system effectively combines three energy-saving methods of pre-cooling,heat recovery and reducing the moisture content of regenerative air.The exergy consumption comparison method is used to verify the energy saving of the system.The results show that compared with the conventional rotor dehurmidification air-conditioning system,the exergy loss of the low-temperature and low-humidity drive double-rotor dehumidification air-conditioning system is reduced by 52.7%,and the exergy efficiency is 7.3%,exergy efficiency increased by 114.7%.The effect of process air inlet parameters,auxiliary air heater outlet regeneration temperature,air heater outlet regeneration temperature,water supply temperature,water supply flow,and pre-cooling flow ratio on system performance was further studied.The evaporative cooling cold water system based on desiccant wheel driven by low temperature and low humidity coupling the low-temperature and low-humidity drive double-rotor dehumidification system and the evaporative cooling is proposed.The mathematical model of each component of the system is established,and programmed and calculated by MATLAB software.The results show that under typical summer conditions in Xi'an,when the system regeneration temperature is 70 ?,the system's outlet water temperature is 17.5 ?,which is lower than the ambient air dew point temperature of 22.5 ?,the wet bulb efficiency can reach 189.2%,and the cooling capacity is 25.1kW.The main performance influencing factors of the above dehumidification system and cold water system were discussed respectively The operating characteristics of the system under different working conditions were studied and the optimization suggestions were given.The effect of process air inlet parameters,auxiliary air heater outlet regeneration temperature,air heater outlet regeneration temperature,return water temperature,return water flow,and surface cooler flow ratio on system performance was further studied.