Research On Airflow Characteristics And Ventilation Effect Of Attached Jet In Sentry Space

There are a large number of toll booths,guard rooms,newsstands and other guardhouse buildings in China.This type of building has many outer protective structures,a large proportion of doors and windows,poor thermal performance of materials,and periodic outdoor solar radiation and air temperature have a significant impact on the indoor environment.They are mostly located in outdoor polluted places,and the intrusion of toxic and harmful substances such as automobile exhaust and road dust can even endanger the health of workers.Based on the sentry space characteristics,functional requirements and the characteristics of the box building in the outdoor environment,the paper proposes a method for controlling the jet ventilation of sentry space,studies its flow mechanism in the box building,and studies its ventilation effect of isolating outdoor solar radiation,pollutants and other external disturbances as well as regulating the indoor environment.In this study,a combination of field theoretical analysis,experimental test and numerical simulation is adopted.Firstly,the basic size of the sentry building,the physical structure of the envelope material and so on are investigated.Secondly,combining the existing attached jet ventilation with the characteristics of sentry building,the attached jet ventilation mode suitable for sentry building is proposed.Then,carried out the outdoor environment experiment test,test the solar radiation,outdoor temperature,outdoor wind,pollutants on the sentry building indoor environment impact;At the same time,the indoor velocity field under the air supply mode of split type air conditioner and double attached air supply mode is tested,which provides an experimental basis for the correctness of turbulence model selection in numerical simulation calculation.Research content,first of all,study the influence of outdoor disturbance on the indoor environment of sentry box building.Under different wind direction,wind speed and the opening and closing of the door,the air flow field around the sentry building and the analysis of the pollutant field are studied.Because the window is a non-closed orifice when the operator is working,the outdoor wind and pollutants will invade into the room through the window,so the focus is on the flow field around the window.Then,the isolation effect of double attached air supply mode on outdoor pollutant invasion in sentry box type buildings is studied,and the regulation effect of this air supply mode on indoor environment under different air supply parameters and loads is further studied.The study found that when the door is not opened,when the wind is in the upwind direction and the leeward direction,the speed near the window is 0.1～0.2m/s,and in the crosswind direction,the speed near the window is 0.05m/s.When opening the door,when the wind is upwind direction,the speed near the window is 1.0～1.5m/s;when the wind is leeward direction and crosswind direction,the speed near the window is0.1～0.2m/s.The average speed of the double-attached air supply work area is mainly determined by the air supply speed,every time the air supply speed increases by0.25m/s,the average wind speed of the working area increases by 0.02～0.03m/s.The supply air temperature has little effect on the average wind speed in the work area.The air supply mode is compared with the Air Curtain Ventilation and the split air-conditioning.It is concluded that the double-attached mode is 0.04m/s lower than that of the split air-conditioning working area;The speed of the working area in the Air Curtain Ventilation is lower by 0.08m/s.The double-attached mode in the sentry building not only meets the comfort requirements of the work area personnel,but also effectively isolates outdoor pollutants and outdoor wind intrusion.For this kind of small space restricted feature,a good air distribution is created in the interior of the sentry building,which ensures the comfort and health of the staff.