Research On The Performance Of Secondary Dehumidification Fresh Air Unit For Radiant Air-conditioning

Conventional air conditioning system usually give priority to temperature parameters and reduce the requirements on humidity parameters,which may cause problems such as strong blowing,mismatch between heat and humidity and poor indoor air quality.Therefore,compared with traditional air conditioning system,Green radiant air conditioning system is favored by people,which is more comfortable and energy efficient.In the radiant air conditioning system,dehumidifier is the core equipment for humidity control,so the development and research of dehumidifier is the inevitable direction of the industry.Firstly,this paper improves the structure of the traditional dehumidifier.Based on the air volume of 500m3/h,a double dehumidification fresh air handling unit with deep cooling function is designed,which have built-in refrigeration cycle and full heat recovery device.In the radiant air conditioning system,the principle of new air volume selection is optimized.Secondly,a simulation model of the double dehumidification fresh air handling unit is established.This section identifies the specific process of simulation calculations.In this paper,the main objects of double dehumidification fresh air handling unit includes air coolers,total heat recovery devices,compressors,condensers,evaporators,new fan and exhaust fan.Each component model in the simulation program is modeled according to the prototype data.Thirdly,the software is used to study the characteristics of the double dehumidification fresh air handling unit,and the unit is subjected to more diversified performance analysis.The main contents include variable cooling capacity,variable face velocity,variable fresh air temperature,variable relative humidity of the fresh air,variable return air temperature,variable distribution of cooling load proportion,variable air volume,variable frozen water volume and variable freezing water temperature.The change of unit performance under different working conditions determine the optimal value range of the parameters.The simulation results show that the reduction of the face velocity can improve the dehumidification capacity of the air cooler and the COP of the unit is higher when it is turned on the full heat recovery unit.The result shows that the ratio between 70%and 80%can achieve the lowest energy consumption of the unit.The calculating results show that the temperature is not sensitive to the change of chilled water flow and the chilled water inlet temperature has a great influence on Several parameters,which include the dehumidification capacity of unit,compressor power consumption and COP of unitFinally,on the basis of the actual design,the experiment of the double dehumidification fresh air handling unit is carried out.This experiment focus on two conditions under the cooling condition,which is the fresh air and the return air.The aim is to verify the correctness of the simulation model by comparing the experimental research with the results of simulation.This topic starts from energy saving and environmental protection.This topic takes environmental comfort based on temperature and humidity as the standard.It provides a strong theoretical basis and practical support for the improvement of the double dehumidification fresh air handling unit.