• Title/Summary/Keyword: Ventilation Fan

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NUMERICAL ANALYSIS OF TUNNEL FLOW INDUCED BY JET FAN (제트팬 운전에 의해 형성되는 터널내 유동에 대한 수치적 해석)

  • Kim, J.Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.10-13
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    • 2010
  • The flow field in road tunnel is influenced by some facts such as piston effect of vehicle's move, operation of ventilation facilities, natural wind and buoyancy effect of fire plume. Among those, jet fan is one of main ventilation facilities especially in longitudinal ventilation system of tunnel. In this study to analyze tunnel flow induced by operation of jet fan, numerical simulation has been carried out. The velocity distributions and streamlines in tunnel are examined to consider the three-dimensional characteristics of tunnel flow caused by jet fan.

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Optimization of Duct System with a Cross Flow Fan to Improve the Performance of Ventilation (환기 성능 향상을 위한 횡류팬을 이용한 덕트 형상의 최적화)

  • Lee, Sang Hyuk;Kwo, Oh Joon;Hur, Nahmkeon
    • The KSFM Journal of Fluid Machinery
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    • v.16 no.1
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    • pp.40-46
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    • 2013
  • Recently, the duct system with a cross flow fan was used to improve the ventilation in various industrial fields. For the efficient ventilation, it is necessary to design the duct system based on the flow characteristics around the cross flow fan. In the present study, the flow characteristics around a cross flow fan in the ventilation duct were predicted by using the moving mesh and sliding interface techniques for the rotation of blades. To design the duct system with the high performance of ventilation, the CFD simulations were repeated with the revised duct model based on the DOE. With the numerical results of flow rate through the ventilation duct with various geometric parameters, the optimized geometry of ventilation duct to maximize the flow rate was obtained by using the Kriging approximation method. From the performance curves of cross flow fan in the original and optimized models of ventilation duct, it was observed that the flow rate through the optimized model is about 16 percent larger than that through the original model.

Evaluation and CFD Modelling of Flow behind Livestock Ventilation Fan for Small-Scale Wind Power Generation (축사 환기팬 후류의 풍에너지 평가 및 기류 형상의 전산유체역학 모델링)

  • Hong, Se-Woon;Lee, In-Bok;Seo, Il-Hwan;Kwon, Kyeong-Seok;Ha, Tae-Hwan;Hwang, Hyun-Seob
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.5
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    • pp.79-89
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    • 2012
  • The objectives of this paper were to evaluate the wind flow behind the livestock ventilation fan for small-scale wind power generation and to make flow profiles of imaginary ventilation fan for future simulation works. The field experiments using typical 50-inch fan indicated that the wind flow behind the ventilation fan had a good possibility of power generation with its high and steady wind speeds up to a distance of 2 m. The expected electricity yield was almost 101~369 W with a small (0.8 m radius) wind turbine. The decline of ventilation fan performance caused by the obstacle was also not significant with about 4 % from a distance of 2 m. The flow profiles for the computational fluid dynamics (CFD) simulation was created by combining the direction vectors analyzed from tuft visualization test and the flow predicted by the rotating fan modeling. The flow profiles are expected to provide an efficient saving of computational time and cost to design a better wind turbine system in future works.

A NUMERICAL STUDY OF THE VENTILATION AND FIRE SIMULATION IN A ROAD TUNNEL (도로터널 환기/제연 시스템 시뮬레이션)

  • Park, Jong-Tack;Won, Chan-Shik;Hur, Nahm-Keon;Cha, Cheol-Hyun
    • Journal of computational fluids engineering
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    • v.11 no.4 s.35
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    • pp.20-25
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    • 2006
  • In the present study, flow characteristics inside a road tunnel are simulated for the ventilation flows due to jet fan system and flows induces by the traffic. Traffic ventilation is numerically simulated by multiple reference frame. From the results of steady state simulation of tunnel ventilation, it is found that the proper ventilation is achieved by the designed jet fan system along with ventilating flow induced by the traffic. A transient simulation is also performed for the case of vehicle fire in the tunnel reversing the direction of rotation of some fans. The results suggest that the heat and smoke can be controlled by the proper changing of fan operation mode. The present results can be used to design proper ventilation system and effective smoke control system as well.

A Study on the Indoor Airflow Pattern by Changing the Location of Mechanical Terminal Unit (실내 급.배기구 위치변화에 따른 실 공기유동에 관한 연구)

  • Choi, Jeong-Min;Cho, Sung-Woo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.3
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    • pp.193-200
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    • 2009
  • The ventilation system of apartments can be divided by supply and exhaust fan, supply fan and exhaust free and supply free and exhaust fan. Recently, the individual ventilation system and central ventilation system which is combined cooling system with duct system are applied to apartment ventilation system. The airflow pattern is affected by location of supply unit and exhaust unit in indoor. This study is to investigate the proper distance between supply unit and exhaust unit using CFD. As a result of this study, the proper distance between supply unit and exhaust unit could be suggested at the interval of 3 m in supply and exhaust fan system and 2.5 m in supply fan and exhaust free.

A Comparative Study on the Auxiliary Fan Pressure and the Ventilation Efficiency in Large-opening Limestone Mine Airways (대단면 석회석 광산 갱도 내 국부선풍기 승압력 및 통기효과 비교 연구)

  • Park, Dongjun;Kang, Hyeonho;Lee, Changwoo
    • Tunnel and Underground Space
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    • v.27 no.1
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    • pp.1-11
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    • 2017
  • Most of the local limestone mines are developed as large-opening underground mines, while mine ventilation is heavily dependent on the natural ventilation and auxiliary systems, rather than the mechanical ventilation system using main fans. The current auxiliary ventilation system with fan and ducting requires optimization since enhanced deployment of diesel equipment demands higher airflow rate and the associated cost is expected to be too excessive for the local mine operators. This paper aims at optimizing the fan capacity for the working site ventilation through comparing the fan pressure in the mine airway and the ventilation efficiency of an axial-flow fan and a propeller fan developed in this study.

A Study on the Ventilation Performance Estimation of Marketing Ventilation Fan Used in the Apartment House Kitchen (공동주택의 주방에서 사용되는 시판 환풍기의 환기 성능 평가에 관한 연구)

  • 송필동;함진식
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2002.11a
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    • pp.315-320
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    • 2002
  • Marketing ventilation fan 3 kinds been using in kitchen of apartment house into compensation discharge performance of contaminant measure. When propane gas burns by gas table, did waste heat into measurement compensation with carbon dioxide that it happens. In measured all type of exhaust fan, discharge performance of carbon dioxide and waste heat was high there are been much displacement. Among A, B, C three types, performance of A type exhaust fan was most superior and performance of C type exhaust fan was most poor

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분배계통에 따른 지하주차장 환기설비 성능의 예측

  • 김경환;이재헌;오명도;김종필
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.10
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    • pp.982-992
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    • 2001
  • In this paper, the performance of ventilation equipments in enclosed parking garages were investigated for several air distribution systems by numerical method. Air change effectiveness of the non-mixing system was 0.42. It meant that more supply air as much as the design supply air was needed to maintain good indoor air quality. In the high speed nozzle ventilating system which is most expensive one, air change effectiveness was 0.54. Therefore this system satisfied to ventilation design. In the jet fan ventilating systems, air change effectiveness for jet fan ventilating system-A with 18 jet fans and jet fan ventilating system-B with 6 jet fans in circulation mixing arrangement were 0.565 and 0.42 respectively. Jet fan ventilating system-C with 6 jet fans in transport mixing arrangement was 0.535. Jet fan ventilating system-A and jet fan ventilating system-C met the ventilation design. But velocity in jet fan ventilating system-A was over 2.0m/s which is inappropriate in human comfort. Therefore this system is not proper to ventilation. Jet fan ventilating system-C was the optimum one for enclosed parking garages among 5 systems examined in this paper.

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Ventilation Analysis according to Jet Fan Location in Long Tunnel (장대형 터널 내 제트 팬 위치에 따른 환기해석)

  • Kang, Shin-Hyung;Byun, Ju-Suk;Lee, Jin-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.5
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    • pp.386-393
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    • 2007
  • This paper studies the ventilation characteristics according to the jet fan location at the long road tunnel using the CFD software 'FLUENT' which is based on the finite volume method. The tunnel model used in the analysis has a length of 1600m, a cross sectional area of $120m^3$, and is composed of 3 lanes and one way. The velocity profile, the distribution of CO concentration and the ventilation flow rate within the tunnel are analyzed, respectively. In the analysis, it is found that the dependence of the ventilation flow rate upon the jet fan location is small, but the CO concentration in the tunnel is at the lowest when the jet fans are installed near the tunnel outlet. An air stream right below the jet fan is almost inactive due to the strong stream injection near the jet fan. Thus, the pollution level below the jet fan must be higher than the other area.

Effects of the Distance between Jet Fans on the Ventilation Performance in a Road Tunnel (제트홴의 이격거리에 따른 터널내 환기특성에 관한 수치적 연구)

  • Kim, Jung-Yup
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.4
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    • pp.25-30
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    • 2011
  • The jet fan is generally used to add thrust in the longitudinal ventilation system of road tunnel and the geometric conditions of jet fan such as the distance from tunnel wall have an effect on the performance of ventilation system. Numerical analyses on the flow in tunnel caused by operation of jet fan are presented to study the ventilation characteristics in tunnel. While the distance between jet fans in parallel installed in tunnel is changed 0.5 L/D to 3.0 L/D, the flowrate and mean velocity through tunnel are calculated for each cases. As the distance between jet fans increases, the flowrate through tunnel increases asymptotically and the momentum of tunnel flow is alike.