Optimal Design And Application Of Dew Point Evaporative Cooling Air Handling Unit In Dry Area

In this paper,the optimal design and application of dew point indirect evaporative cooling air conditioning units in dry areas are studied.Firstly,the existing evaporative cooling air conditioning units are classified into single stage evaporative cooling air conditioning units,two-stage evaporative cooling air conditioning units,three-stage evaporative cooling air-conditioning unit and compound evaporative cooling air-conditioning unit.At the same time,the application effect in different areas is summarized and summarized.The average temperature drop of the single-stage evaporative cooling air conditioning unit is 4℃,The efficiency of the unit is generally between 60%and 95%.Two or three evaporative cooling air conditioning unit temperature drop is generally between 14 to 22 degrees,the unit efficiency of 106%to 127%.Secondly,the dew point indirect evaporative cooling air conditioning unit is studied theoretically,the structure of the unit is studied,mainly 10000 m~3/h and 20000 m~3/h.At the same time,the operating principles of the unit are described:Use wet channel air dry bulb temperature and dew point temperature difference between the cooling.It also studied the air flow within the unit and how it cooled the unit.At the same time,the design and calculation of the unit,including the determination of outdoor weather parameters,to determine the indoor calculation parameters,the face of the wind speed,the unit shape design,design and calculation of the function section and equipment selection,equipment selection mainly for pump selection and fan Selection.The dew point indirect evaporative cooling air conditioning unit experimental study,through a period of about a week of testing found that in Fuzhou,such high humidity areas,the unit is running well with good cooling effect,the average temperature in sunny days can reach 7℃,even if In rainy days there are about 4℃temperature drop,while the unit efficiency is higher,generally up to 110%,up to 120%,which is far more than ordinary indirect evaporative cooling air conditioning unit,In addition,Fuzhou area itself humidity comparison Large,about the moisture content of 21 g/kg,the unit average humidification moisture content of 1 g/kg,showing unit humidification is not large,basically meet the needs of the indoor environment,but also for different exhaust volume and air volume comparison test,Found that the ratio of about 0.5 to achieve the best.At the same time,the COP of the unit is an average of 8 and it is very energy-efficient.The dew point indirect evaporative cooling air conditioning units of the actual engineering applications,mainly in an industrial workshop in Yangling of Shanxi Province,a food factory in Xingping City of Shaanxi Province and an airport in Dunhuang of Gansu,where an industrial workshop in Yangling a detailed design,selection And the calculation,while the other two places only conducted the unit test.The test found that in these three places,the unit temperature drop in the basic 7~11℃,cooling effect is good,the unit wet bulb efficiency of about 110%,up to 120%,the same with the Fuzhou experiment,meet the requirements.At the same time in different regions of the unit to increase the air content of the moisture content is different in Shaanxi Yangling,Xingping,Dunhuang unit air outlet average moisture content were 5.5 g/kg,0.8 g/kg,2.1 g/kg,This is related to meteorological parameters in various places.However,the dew point indirect evaporative cooling air conditioning unit has the most obvious application effect in dry areas such as Dunhuang.The average temperature drop is 11.43℃,which is very suitable for popularization in the dry areas.In the semi-arid areas,Production sites have strict humidity requirements,you need to pay attention to control humidity.Finally,the problems of the indirect evaporative cooling aircrew in dew point experiment and actual engineering application are optimized,and according to the structure of the unit and the influencing factors of the performance of each functional section,according to the usage in different regions and different places,Cooling air conditioning unit optimization program,mainly in the following aspects:the addition of circulating water tank to the unit,an increase of automatic control system,control unit exhaust volume and air supply ratio of about 0.5,optimize the material,the rational design of the unit flow channel,take Different filtering measures,designed to send exhaust system.