Research On The Application Of Annular Air Inlet In Air Conditioning System

Large temperature difference air supply system features large temperature difference of air supply and small air volume,which reduces the treatment of primary air and the air laying of conveying equipment,as well as the power of the fan and the size of the air duct,making the large temperature difference air supply system can reduce the initial investment and operation cost of the project.However,the large temperature difference air supply system has a higher requirement for the equipment at the end of the air inlet.It needs to be able to quickly mix with the surrounding air after the wind enters the room,so as to avoid uneven indoor temperature and make people feel uncomfortable.Based on this problem,this paper presents a new type of annular air inlet terminal device suitable for large temperature difference air supply system.This paper briefly summarizes the research status of annular jet and large temperature difference air conditioning system,the problems of complicated process and poor air distribution at the air inlet terminal device of the large temperature difference air supply system are presented.Then,a model of annular air inlet terminal device is designed,which may be suitable for large temperature difference air supply system,in order to verify whether the annular air inlet terminal device meets the requirements of large temperature difference air supply system.In this paper,the basic flow law of annular jet is studied by CFD numerical simulation and experimental verification.Obtained by curve fitting method in air conditioning system within the scope of the wind speed of annular jet speed axial velocity decay curve formula of axial temperature decay curve formula,and get the diffusion section of annular jet and jet distance into slope of 0.28 a linear relationship,the jet flow direction and x is about 10 ° Angle,airflow mixing point about in jet distance is about 0.65 m.By comparing the suction volume of the annular air inlet with that of the whirling wind mouth,it is found that the multiple of the suction volume of the annular air inlet 0.8m away from the air inlet is20.45 times,and the multiple of the suction volume of the whirling wind mouth is 16.68 times.By establishing the distance model between different annular air inlet and ceiling,and studying the influence of air inlet placement distance on the volume of suction,the recommended installation distance of annular air inlet is 15cm-25 cm.On this basis,the large temperature difference air supply annual air inlet air conditioning room simulation model is established,through the characteristics of air distribution index of ADPI of annual air inlet air distribution is analyzed,the results show that under the condition of three conditions in the summer annual air inlet ADPI average of 93.8%,winter conditions ADPI average of 94.3%,are far larger than ADPI index 80%,pertaining to the annual air inlet has the very good air distribution performance.By studying the temperature difference between the annular air inlet in vertical and horizontal directions,the maximum temperature difference between the air inlet in the working area in summer is 1.2? in horizontal direction and 0.6? in vertical direction.In winter working conditions,the maximum temperature difference of the air inlet in the working area is 0.6? in the horizontal direction and 0.2? in the vertical direction,so there will be no local overheating in the room.Finally,the paper will ring of air inlet diameter,the guide surface outlet Angle and slot width as variables,through the numerical simulation analysis,the annual air inlet is obtained under different structural parameters of air distribution,it is concluded that the optimal diameter annual air inlet area of 30 cm-36 cm,annual air inlet optimal diversion Angle for 0°,the optimal outlet annual air inlet slit width is 1.5 mm,this is after the application of annual air inlet in air conditioning system provides the reference and suggestion.