• 제목/요약/키워드: Back-fire

검색결과 207건 처리시간 0.021초

인화귀원(引火歸原)의 병기론 연구 (Pathological Mechanistic Study of Conducting Fire Back to Its Origin)

  • 조원준;김영목
    • 동의생리병리학회지
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    • 제21권4호
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    • pp.795-802
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    • 2007
  • The fire not to back to its origin(火不歸原) is said that source yang(元陽) of sea of qi(氣海) rises because fire(火) of lower energizer(下焦) can't return to its origin. Successive medical men regarded the cause of it as yang deficiency(陽虛) or yin deficiency(陰虛) generally, but Jangseoksun(張錫純) presented eight kinds of cause, they are syndrome of upcast yang(戴陽證), deficiency of qi(氣虛), yin deficiency, yin and yang deficiency(陰陽虛), thoroughfare qi ascending counterflow(衝氣上衝), heart fire(心火), yang deficiency with cold fluid retention(寒飮) in middle energizer(中焦寒飮), yang deficiency with sunken cold locked in(沈寒錮冷). The method of conducting fire back to its origin may be the treatment of fire not to back to its origin as an interpretation of the phrase in a broad sense, but it is limited to yang deficiency with sunken cold locked in besides syndrome of upcast yang as the treatment based on pathological conditions. By this standpoint Eunsuryong(殷壽龍) used conducting fire back to its origin to remove hidden cold(伏寒) and make rising false fire(假火) settle. The meaning of conducting fire back to its origin is not just raise yang qi(陽氣) but break sunken cold locked in by using the drugs like Buja(附子), Yukgye(肉桂). Jakyak(芍藥) can concentrate yang qi on the life gate(命門) by converging it, Sukjihwang(熟地黃) can supply yin essence(陰精) and check the intense nature of tonifing yang(補陽) drugs. So if we want to use the method of conducting fire back to its origin, we should confirm the symptoms of sunken cold locked in and yang deficiency not to misdiagnose yin deficiency.

밸브 오버랩 기간이 없는 흡기관 분사식 수소기관의 성능 및 역화특성 (Characteristics of Performance and Back-Fire for External Mixture Hydrogen Fueled Engine without Valve Overlap Period)

  • 이광주;강준경;;노기철;이종태
    • 한국수소및신에너지학회논문집
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    • 제18권4호
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    • pp.374-381
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    • 2007
  • In order to verify the feasibility of expansion of back-fire limit equivalence ratio in the hydrogen-fueled engine with external mixture, the characteristics of performance and combustion are experimentally analyzed with change of intake/exhaust valve timings under the fixed valve overlap period of $0^{\circ}$ CA(non-valve overlap period). These characteristics are also tested for the change of exhaust valve closing timing while intake valve opening timing is fixed to clear the main cause of back-fire occurrence. As the results, the less valve overlap period center is retarded, the more back-fire limit equivalence ratio increases and back-fire does not occurred after TDC. In addition, it was shown that the control of back-fire is dependent on intake valve opening timing than valve overlap period.

가연성 배기덕트-흄 화재위험성 평가에 관한 연구 (A Study on the Fire Risk Assessment of Combustible Exhaust Duct-fume)

  • 윤여송;이영순
    • 한국안전학회지
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    • 제25권1호
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    • pp.32-37
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    • 2010
  • When back-out & firing Process applies heat, hume is piled up in exhaust duct by organic compound and it have high dangerousness. There by, the process is happening a lot of damage that is exhaust duct fire. However we do not have certain fire dangerousness estimation and digestion countermeasure. So we need preventive measure. Back-out & firing is a process which has fine structure, electrical and mechanical characteristics, such as firing kiln and back-out kiln which has pipe line and box type. The box oven is made of heating coil, fan motor and control panel. Back-out & firing process has air circulation institution of quick ventilation type. When we operate this process for long time, fire can break out easily. Duct is made by zinc shredder. If fire breaks out in duct inside, fire by deposit fume can be dispersed easily. Accordinglym, This project estimate danger for back-out & firing process exhaust duct through real fire test. And there is purpose of study to establish preventive measure.

동일열량공급하의 밸브오버랩기간 변화에 대한 역화억제 검토 (A Investigation of Back Fire Control with Valve Overlap Period Change In the Same Supply Energy)

  • 강준경;;노기철;이종태
    • 한국수소및신에너지학회논문집
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    • 제18권3호
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    • pp.348-355
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    • 2007
  • To grasp a feasibility of back fire control by valve overlap period, back fire limit equivalence ratio was estimated with valve overlap period which has the same supply energy and positive intake pressure as valve overlap period $300^{\circ}\;CA$. As the result, it was shown that the smaller valve overlap period has the higher back fire limit equivalence ratio under valve overlap period $300^{\circ}\;CA$ as well as VOP $0^{\circ}\;CA$. This result means that expansion of back fire equivalence ratio by decreasing valve overlap period was caused by decrease of back flow duration of flame from in-cylinder to intake port than decrease of lower supply energy.

외근직 소방공무원의 직무유형에 따른 요통발생의 차이 (Differences in Incidence of Lower Back Pain according to Fire Fighters' Duty Type)

  • 홍성기;임정수;윤성태;임준
    • 보건행정학회지
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    • 제17권4호
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    • pp.99-112
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    • 2007
  • The purpose of this study was to analyze the effect of fire fighters' duty type on occurrence and severity of low back pain. Data were collected with questionnaire to 450 fire fighters working at 119 safety center and rescue unit of 30 fire stations in Gyeonggi-do. Finally the study was analyzed for 360 persons among them. The risk of experiencing of lower back pain occurred in the order of Rescue[odds ratio(OR) 3.36, 95% confidence interval(95% CI) 1.18-9.52], Vehicle operation(OR 2.63, 95% CI 1.26-5.50), First aid(OR 2.18, 95% CI 1.03-4.59), and Putting out a fire. The risk on severity of lower back pain occurred in the order of Vehicle operation(OR 4.00, 95% CI 1.57-9.80), First aid(OR 1.88, 95% CI 1.00-4.81), Putting out a fire, and Rescue. These result suggest that duty type of fire fighters may be a prognostic factor for occurrence and severity of low back pain. The potential implications of these findings are discussed about different approach for primary and secondary prevention by duty type of fire fighters.

터널화재유동의 역기류 해석을 위한 LES 및 RANS 결과의 비교 고찰 (Comparative Study on The Numerical Simulation for The Back-Layer of The Tunnel Fire-Driven Flow with LES and RANS)

  • 장용준;김학범;김진호;한석윤
    • 대한기계학회논문집B
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    • 제33권3호
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    • pp.156-163
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    • 2009
  • In this study, comparative analysis on the back-layer phenomena in the tunnel-fire driven flow is performed using numerical simulation with LES and RANS. FDS(Fire Dynamics Simulator) code is employed to calculate the fire-driven turbulent flow for LES and Smartfire code is used for RANS. Hwang and Wargo's data of scaling tunnel fire experiment are employed to compare with the present numerical simulation. The modeled tunnel is 5.4m(L) ${\times}$ 0.4m(W) ${\times}$ 0.3m(H). Heat Release Rate (HRR) of fire is 3.3kW and ventilation-velocity is 0.33m/s in the main stream. The various grid-distributions are systematically tested with FDS code to analyze the effects of grid size. The LES method with FDS provides an improved back-layer flow behavior in comparison with the RANS (${\kappa}-{\epsilon}$) method by Smartfire. The FDS solvers, however, overpredict the velocity in the center region of flow which is caused by the defects in the tunnel-entrance turbulence strength and in the near-wall turbulent flow in FDS code.

Plume의 주기성이 연층형성에 미치는 영향 (A Characteristics of Smoke Layer Formation Affected Periodicity of Fire Plumes)

  • 한용식;김명배;오광철;신현동
    • 한국화재소방학회논문지
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    • 제16권2호
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    • pp.38-42
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    • 2002
  • ON-OFF 제트를 사용하여 plume의 주기성이 천장아래에 형성되는 연층에 미치는 정성적인 영향을 파악하였다. 사용된 연기는 가열에 의해 증발된 kerosene 입자를 섞은 질소가스이다. Laser sheet에 의해 산란된 유동장의 순간 상들은 디지털 비디오 카메라에 의해 녹화되었다. ON-OFF 제트와 연속제트의 연층형성 과정을 비교하므로서 화원근처에 형성되는 연층은 plume과 천장의 주기적인 충돌에 의해 지배됨을 확인하였다. 또한 plume의 주기적인 충돌은 연층을 두껍게하며, back-flow를 일으킴을 확인하였다.