AIR CURTAIN CHARACTERISTICS INVESTIGATION OF THE HIGH TEMPERATURE VEHICLE PAINTING DRYING WORKSHOP

Chen Yue,Le Tong,Murong Ge,Furui Wang,Weifeng He,Pengju Gao,Youde Peng 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.2

Installing the air curtain for painting drying workshop is an effective method for continuous vehicle in and out. A top injection air curtain is designed for the high temperature vehicle painting drying workshop in this research. Based on the numerical simulation method, the effect of key operating parameters and working state of the air curtain on the stability and thermal dissipation performance of air curtain have been investigated. The results showed that increasing both the air curtain injection velocity and injection angle improved the stability of the top injection air curtain. Both the optimized air curtain injection velocity and the air curtain injection angle are obtained to achieve the lowest thermal dissipation effect at the fixed workshop height. The stability of the air curtain declines sharply and the thermal energy dissipation of the workshop increased obviously at high workshop height. With the vehicle skeleton passes through the air curtain, the stable gas barrier is destroyed, and the thermal dissipation is increased compared without vehicle passing. The low air curtain jet velocity is recommended with vehicle through the air curtain. Moreover, the small distance between the car bottom to the ground, and the quickly vehicles passing air curtain are suggested in actual operation.

외부바람의 영향을 고려한 난방공간에서의 하향토출 에어커튼의 성능

성순경(Sun-Kyung Sung) 대한설비공학회 2009 설비공학 논문집 Vol.21 No.7

Air curtains are widely used for gates of shopping mall, warehouse, cold stores and refrigerated display cabinets. The purpose of the air curtain is to reduce the infiltration of outdoor air and heat loss from the air conditioning space to ambient air. Design data for the air curtain given by previous researchers do not mention the influence of wind speed. Thus, this paper presents a performance of single jet air curtain in heating space when the wind blows toward the opening space of the building. A numerical simulation is used to study the influence of various parameters on the efficiency of the downward-blowing air curtain device which is installed inside of the wall above the door. The performance of the air curtain is evaluated by sealing efficiency which provides the assessment of the energy savings. A new safety factor is also proposed for determination of air curtain jet velocity under the various wind conditions.

Study on the Evaluation of Sealing Performance of Horizontal Blowing Air Curtain Installed in Doorways

권용일 대한설비공학회 2021 International Journal Of Air-Conditioning and Refr Vol.29 No.1

Air curtains are installed to reduce heat loss due to drafts intruding into the indoor through the open doorways, and play the role of separating two climatic zones and different environmental zones. It is also used to protect the workplace from impurities or to reduce the spread of cigarette smoke in restaurants. Recently, aircraft to provide the individual air barrier by the vertical blowing air curtains have installed a physical barrier in the breathing zone between adjacent seats to protect passengers from COVID-19. The main factors affecting the sealing performance (SP) of the air curtain are the difference of temperature and pressure between indoor and outdoor, and are used to make the proper jet flow an air barrier with the high airtightness. Until now, various types of air curtains are manufactured and sold. Air curtains with the improved SP do not only have a discharge port but also a suction port. This study was conducted to evaluate the SP of the horizontal blowing air curtain according to the discharge pressure, and to select the minimized volume flow rate required for creating the proper zone separation. The volume flow rate of outdoor air intruding into the indoor through the doorways is used to evaluate the SP of the air curtain, and is calculated using the SVE4 proposed by Murakami in this study.

공조공간에서 수평토출형 에어커튼의 차단 성능

성순경(Sun-Kyung Sung) 대한설비공학회 2012 설비공학 논문집 Vol.24 No.11

Air curtains are widely used in commercial and public buildings to replace solid doors where traffic of people is predicted. At doorways where the solid door is open continuously or intermittently, an air curtain may be installed in order to reduce the flow of heat and moisture from the enclosed space to the outside. The purpose of this paper is to predict isolation performance of the single-sided air curtain when the wind is blowing. For the study, a numerical simulation is used to find the influence of various jet velocities on the efficiency of the single-sided air curtain device which is mounted at the side of the doorway. The isolation performance of the single-sided air curtain is evaluated by sealing efficiency which provides the assessment of the infiltration air ratio. According to the result of this study, the single-sided air curtain has lower sealing efficiency than downward-blowing air curtain. Therefore, for energy conservation in heating space, the single-sided air curtain is not recommended because of its low effectiveness.

유도공기 및 에어커튼을 이용한 주방 레인지후드 성능 개선에 관한 수치모사

손덕영(Deok-Young Sohn),임지홍(Ji-Hong Lim),최윤호(Yun-Ho Choi),박재훈(Jae-Hoon Park) 대한설비공학회 2007 설비공학 논문집 Vol.19 No.4

In an apartment house that is generally air-tight and well insulated, the combustion gas from cooking devices is the major source of air pollution in the kitchen. It spreads throughout the house affecting the overall indoor air quality. In this study, the performance of the kitchen range hood which employs air induction and air curtain was investigated by numerical simulation. The results are compared with that of two other kitchen range hoods which are in general use. The two general types of range hoods considered in the present calculations are box and plate type range hoods. The former has a large capture space between the filter and suction duct, while the latter has little. It was found that the capture efficiency of the kitchen range hood with air induction and air curtain is higher than that of the general types of range hoods by 20% approximately. The reason may be because the air induction and the air curtain block the air stream escaping from the front and the side part of range hoods effectively and because an additional fan for air induction and air curtain increases suction flow rates.

난방공간에서 에어커튼의 토출각도 변화에 따른 성능 변화

성순경(Sun-Kyung Sung) 대한설비공학회 2010 설비공학 논문집 Vol.22 No.2

Air curtains are widely used for gates of shopping mall, warehouse, cold stores and refrigerated display cabinets. The purpose of the air curtain is to reduce the infiltration of outdoor air and heat loss from the air conditioning space to ambient air. The discharge angle of air curtain is very important as the sealing efficiency is affected by it. This paper presents a performance of single jet air curtain in heating space when the discharge angle of nozzle changes. A numerical simulation is used to study the influence of various parameters on the efficiency of the downward-blowing air curtain device which is installed inside of the wall above the door. The performance of the air curtain is evaluated by sealing efficiency which provides the assessment of the energy savings. A condition of discharge angle that has the highest sealing efficiency is proposed.

Numerical study of air curtain systems for blocking smoke in tunnel fires

Uk-Hee Jung,Sung Kim,Sang-Ho Yang,Jin-Hyuk Kim,Young-Seok Choi 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

A tunnel fire is very dangerous to drivers because of generated poisonous gases. For dealing with this hazardous situation, ventilation systems for smoke control are installed so that drivers can be safely evacuated from the site of the fire. An air curtain system is one of these ventilation systems, and such a system in a tunnel generates an air wall to block the passage of poisonous gases. In this study, airflow discharge patterns of air curtain systems were analyzed using Computational fluid dynamics (CFD), with two design parameters— to predict the ability of the air curtain to block the contaminated adverse air-flow in the tunnel. The considered two design parameters were the installed angle of the slit nozzle (N A ) and the discharged air velocity at the slit nozzle outlet (N V ). The tunnel geometry for the CFD analysis was a two-lane type with a tunnel length of 100 m and an elliptical cross section. The height of the tunnel was approximately 7.3 m and the height of the installed air curtain was about 4.9 m from the road surface. In this study, the heat release rates of the fire, the distance from the fire site, and the temperature of the working fluid were respectively assumed to about 20 MW, 50 m and 473 K, on the basis of the NFPA 502. The CFD analysis demonstrated that an N A of 0 deg could not block the adverse air flow due to a realistic tunnel inlet-outlet static pressure difference (ΔP S ). An N A of 20 deg was required to effectively block the adverse flow. The blocking failure first formed at the sidewall of the tunnel, and it proceeded toward the center of the tunnel cross section when the adverse wind was strong. That aspect of the blocking failure was judged to be due to the fact that the tunnel cross section is elliptical. Anyway, when the tunnel ΔP S was increased, that showed the need for a high N V .

급기노즐과 배기후드를 포함하는 에어커튼을 이용한 연기확산 차단시스템에 대한 연구

김정엽,이수각 한국방재학회 2015 한국방재학회논문집 Vol.15 No.6

화재 발생시 전체 사망자의 70% 이상이 연기에 의한 것으로 산정되면서 인명안전에 가장 큰 위협이 되고 있는 연기에 대처하기 위한 연기제어 설비의 중요성이 강조되고 있다. 선진외국에서는 높은 속도의 제트류를 이용해서 공기막을 형성함으로써 연기의 확산을 차단하는 방안에 대해 많은 연구가 수행되고 있다. 본 연구에서는 연기확산 차단 시스템으로서 급기노즐과 배기후드를 포함하는 에어커튼 시스템을 제안하고 실규모의 실험장치를 제작하여 제트기류에 대한 측정을 수행하였으며, 동일한 조건에 대한 3차원 수치해석을 수행하였다. 또한 급기노즐의 분출속도와 연기의 유동속도를 중심으로 에어커튼의 연기 차단효과를 수치적 방법으로 분석하였다. 연구결과 급기노즐의 분출속도가 20 m/s이고 연기의 유동속도가 1 m/s인 경우에서는 유입된 연기유량의 12.9%가 에어커튼을 통과하고, 76.3%는 에어커튼에 의해 차단된다. More than 70% of the fatalities by fire is attributable to smoke and thus the importance of smoke control system is increasingly emphasized in a bid to deal with the smoke that has threatened the life safety. In advanced countries, many studies on forming the air curtain using a fast jet flow to block the smoke from spreading have been underway. In this study, air curtain system containing supply nozzle and exhaust hood is proposed as smoke blocking system and a full-scale test device was fabricated to measure the jet flow as well as 3D numerical analysis under the same condition was implemented. Furthermore, smoke blocking effect of air curtain system was numerically analyzed, focusing on ejection velocity of supply nozzle and smoke flow velocity. Consequently, when ejection velocity of supply nozzle was 20 m/s and smoke flow velocity was 1 m/s, 12.9 % of smoke flow passed through air curtain while 76.3% was blocked by air curtain.

지하철 객실 내 에어커튼의 미세먼지 차단 효용성의 수치해석 연구

현예솔,오근우,양민규,최지용,최정일 한국전산유체공학회 2022 한국전산유체공학회지 Vol.27 No.4

This study evaluates the effectiveness of air curtains in alleviating contaminant infiltration to subway cabins when doors are opened. We perform numerical simulations of contaminant transports in the subway station under various conditions(passenger ingress, air curtain operation, seasonal effect, and pressurized cabin). The performance of the air curtain is assessed based on mass transfer rate and separation efficiency. Air curtain-induced air flows promote particle infiltrations into the cabin by lowering the cabin pressure. However, the temperature and pressure differences between in and out of the cabin do not significantly affect the separation efficiency, except for no air curtain operation.

개문영업 상가건물 에너지손실 저감을 위한에어커튼의 최적 토출각도 분석에 관한 연구

박민준,이정재 대한건축학회지회연합회 2023 대한건축학회연합논문집 Vol.25 No.4

In this study, the optimal supply angle of the air curtain installed above a store entrance was reviewed via a transient CFD simulation to reduce heating and cooling energy consumption from opening doors during business hours. As a result of the simulation, when the air curtain is installed, the amount of infiltration is drastically reduced. During the summer season, it is advantageous to supply air angled towards the outdoor side rather than indoor side of an entrance door in cooling conditions, with an angle of 10°⃚ most effective for outdoor temperatures of 30℃, 33℃, and outdoor side 10°⃚ angle for outdoor temperatures of 36℃. In the winter season, it is more advantageous to supply air to indoor side rather than outdoor side of an entrance door in heating conditions and with an angle of 20°⃚ most effective for outdoor temperatures of -6℃, -9℃, and indoor side 10°⃚ angle for outdoor temperatures of –12℃. 본 연구에서는 개문영업에 따라 발생되는 냉난방에너지 손실량을 저감시키기 위해 개구부 상부에 설치되는 에어커튼의 실내외 온도차별 최적 토출각도를 CFD 시뮬레이션을 실시하여 분석하였다. 개문 영업시, 개구부에 에어커튼을 설치하지 않은 경우, 냉방시에서는 실내 찬 공기는 개구부 아래쪽에서 실외로 유출되며, 외부 뜨거운 공기는 개구부 위쪽에서 실내로 유입되고, 난방시에는 반대방향의 침기가 발생한다. 여름철 개문냉방시 에어커튼을 가동할 경우, 실내보다 실외측으로 에어커튼 기류를 토출하는 것이 침기량 저감에 유리하며, 실외온도가 30℃, 33℃의 경우 실외측 20˚, 외기온도가 36℃의 경우 실외측 10˚각도가 가장 효과적으로 침기량을 저감시킬 수 있다. 겨울철 개문난방시에는 여름철과 반대로 실외보다 실내측으로 에어커튼 기류를 토출하는 것이 침기량 저감에 유리하며, 실외온도가 –6℃, -9℃의 경우 실내측 20˚, -12℃의 경우 실내측 10˚각도로 토출하는 것이 침기량 저감에 가장 효과적인 것으로 나타났다.