• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.405-410
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• 2006

This paper presents a control algorithm of supply and exhaust diffusers by recognizing a contaminant source location. CFD analysis has been conducted to calculate steady state airflow and concentration distributions in a model room, which has two supply and two exhaust openings on the ceiling. Calculations have been performed for five cases out of nine different ventilation modes by combining on/off control of the supply and exhaust openings. Local mean residual life times are obtained and compared at 9 internal points for each ventilation case. Depending on the contaminant source location, the ventilation system is operated at an optimum ventilation mode, which can results in maximum exhaust performance.

• 설비공학논문집
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• 제21권2호
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• pp.103-108
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• 2009

Local exhaust system used in toilet and cooking place of low-rise public house installed roof ventilator at terminal of stack. There are many high riser public houses in Korea. These buildings were not viewed as being major contributors to exhaust pollutants producted in indoor. It was because many engineers thought that exhaust in high riser public house depends on stack effect. But Neutral pressure level represents in a terminal of stack with air tightness for the best exhaust efficiency. Thereby, lower floors have the worst indoor air quality. This paper focuses mainly on the exhaust efficiency improved by roof fan with motor installed in high riser public house. It is observed there is higher exhaust efficiency than the existing natural roof ventilator.

• 한국산업보건학회지
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• 제20권1호
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• pp.1-9
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• 2010

Objectives : The purposes of this study were to evaluate exhaust ventilation systems(EVSs) and to suggest problems and improvements. Methods : For 50 small and medium-sized enterprises, we carried out evaluation of EVSs. We evaluated hoods with smoke tester and measurement of capture velocity. In addition, we used several indicators for performance evaluation designed in this study. Results : 1. Based on the smoke flow pattern and the criteria of occupational health and safety act, 67.8% of hoods were rated 'good' level at smoke test whereas 26.3% were rated 'good' level at measurement of capture velocity. 2. 29.3% of hoods, of which ratio of measured actual air flow at hood(Qah) to required ideal exhaust air flow at hood(Qih) was 1 or more, were rated 'good' level. 3. The % of EVS, of which ratio of measured actual air flow at stack(Qast) to total required ideal exhaust air flow at hood(Qith) was 1 or more, was 29.0%. 4. For the ratio of measured Qast to existing air flow at fan(Qfan), only 5% of EVSs were 1 or more and 26.0% were 0.8 or more but less than 1.0. 5. For the ratio of measured Qast to total measured actual exhaust air flow at hood(Qath), 74.0% were 0.8 or more but less than 1.0. 6. The percentage of EVS, of which ratio of total measured Qath to existing Qfan was 0.8 or more, was 19.0%. 7. The percentage of EVS, of which ratio of total measured Qath to total required ideal exhaust Qith was 1 or more, was 26.0%. 8. For the comprehensive evaluation indicators designed in this study, 29.0% were 0.8 or more. Conclusions : We found that few exhaust local ventilations at small and medium-sized enterprises were rated 'good' level and that most exhaust local ventilations had 'poor' design and installation. Therefore, relevant professional manpower and enterprises have to construct exhaust local ventilation where it is needed, and technical guidance and economic support are needed to improve 'poor' exhaust local ventilation after self-evaluation.

• 한국소음진동공학회논문집
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• 제16권9호
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• pp.964-970
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• 2006

Micro gas turbine(MGT) has received attention recently as small-scale distributed power sources. With characteristics such as their small size, lightweight, low maintenance cost and minimal vibrations during operation, they are expected to become widespread in a wide range of ' applications, including residential and small-scale industrial use. It is very easier to start-up and stop the MGT system which is the friendly environmental power system has just below the 9ppm NOx emmission and good quality of noise level. The exhaust heat emitted by the MGT is in the form of about $300^{\circ}C$ clean exhaust gas. The exhaust gas is suitable for absorption chiller/heater system. 1 has researched performance characteristics of the 60 kW class MGT-absorption chiller-heater system in the local condition. Variations of heat recovery from exhaust gas has measured according to micro gas turbine output of 15, 30, 45, 60kW. From those results, the performance of the MGT-absorption chiller/heater system has been evaluated.

• 한국가스학회지
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• 제22권3호
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• pp.74-83
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• 2018

국소배기장치를 설치하려는 경우 환경부 허가를 받더라도 고용노동부 허가를 새로 받아야 한다. 이는 대기환경보전법 뿐만 아니라 산업안전보건법 제48조2에 따른 제조업 유해위험방지계획서를 착공 15일 전까지 제출하도록 되어 있기 때문이다. 현행 환경부 대기환경보전법에서는 국소배기장치의 오염원을 대기 중으로 배출되는 부분만 규제하고 산업현장 내에서의 근로자 안전보건에 관한 내용은 산업안전보건법 등 고용노동부 소관 법률로 관리된다. 환경부의 승인을 받은 것임에도 고용노동부의 불승인 사례가 증가하여 생산지연 및 추가 개선비용에 따른 사업장의 불만이 커지고 있다. 또한, 화재 폭발의 위험성이 큰 국소배기장치의 경우 화재 폭발에 의한 중대산업사고 위험성이 증가하고 있다. 원인은 배풍량, 제어속도, 반송속도, 덕트구경, 화재폭발 위험성 등의 설계가 미흡했기 때문이다. 이는 국소배기장치 승인기준 및 절차는 대동소이 하나 산업안전보건법에서 근로자의 안전보건 및 화재 폭발에 대한 심사항목이 추가되어 있기 때문이다. 본 연구에서는 환경부와 고용노동부에서 이원화 되어 있는 국소배기장치 설치 승인기준을 비교 분석하여 합리적인 제도운영 방안을 모색하고자 한다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.802-806
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• 2004

For the protection of the local air quality and the global atmosphere, the emissions of trace species including nitric oxides (NO and NO$_2$) from gas turbines are regulated by local governments and by the International Civil Aviation Organization. In-situ measurements of such species are needed not only for the development of advanced low-emission combustion concepts but also for providing emissions data required for the sound assessment of the effects of the emissions on environment. We have been developing a laser absorption system that has a capability of simultaneous determination of NO and NO$_2$concentrations in the exhaust jets from aero gas turbines. A diode laser operating near 1.8 micrometer is used for the detection of NO while a separated visible tunable diode laser operating near 676 nanometers is used for NO$_2$. The sensitivities at elevated temperature conditions were determined for simulated gas mixtures heated up to 500K in a heated cell of a straight 0.5 m optical path. Sensitivity limits estimated as were 30 ppmv-m and 3.7 ppmv-m for NO and NO$_2$, respectively, at a typical exhaust gas temperature of 800K. Experiments using the simulated exhaust flows have proven that $CO_2$ and $H_2O$ vapor - both major combustion products - do not show any interference in the NO or NO$_2$ measurements. The measurement system has been applied to the NO/NO$_2$ measurements in NO and NO$_2$ doped real combustion gas jets issuing from a rectangular nozzle having 0.4 m optical path. The lower detection limits of the system were considerably decreased by using a multipass optical cell. A pair of off-axis parabola mirrors successfully suppressed the beam steering in the combustion gas jets by centralizing the fluctuating beam in sensor area of the detectors.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2001년도 춘계 학술대회
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• pp.95-96
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• 2001

• 한국산업보건학회지
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• 제17권3호
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• pp.212-223
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• 2007

18 Local exhaust ventilation systems in 10 melting companies located in an industrial complex were tested to know the status of maintenance. Test items were fan flowrates, fan static pressures, rotational speeds and differential pressures of bag filters. Only 22% of the tested fans has more than 80% flowrate efficiency. 44% of the fans has lower than 60% efficiency. The performance of the fans are not in a good status. For the fans with lower than 60% efficiency, the analysis shows that the lower flowrate might be caused by the degradation of fan performance. On the other hand, for the fan s with higher than 60% efficiency, the main cause of flowrate reduction might be too much pressure losses due to clogging of filter bags. The degradation of fans usually lead the reduction of hood capture efficiency, resulting in the increase of contaminant concentrations in workplace. To keep fans in good status, self inspections should be periodically conducted. This inspection should include the measurements of flowrate and pressures. The most important thing to be performed is the initial test of local exhaust ventilation system because the initial test data should be used to know the level of system degradation.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권1호
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• pp.49-56
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• 1998

This study identified the fumes produced from the cooking of the seasoned meats containing various condiments such as garlic, onion, pepper, soy sauce, and sesame oil. Concentrations, at the breathing zone of the cook, of volatile organic compounds (VOCs) and aldehydes included in the cooking fumes of seasoned meats were identified. Many chloro and fluoro-aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and aldehydes, which could be carcinogen suspecting chemicals, were producing from the cooking fumes of the seasoned meats. This study also identified the ventilation efficiencies of the cooking fumes of the six exhaust ventilation systems, which were widely being used in the general apartments, houses, and small-food factories. For a comparison of the ventilation efficiencies of the systems, acetaldehyde was chosen as a marker pollutant and its concentrations at the breathing zone of the cook were identified. The laboratory fume hood showed the best ventilation efficiency of the six ventilation systems studied, and then the lateral hood ventilation and the down draft ventilation followed the laboratory fume hood. Finally, this study identified that both a wall factor nearby pollutant sources and a distance factor between the hood face and pollutant sources should be also considered for an effective local exhaust ventilation system design.

• 한국환경과학회지
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• 제2권1호
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• pp.49-56
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• 1993

This study identified the fumes produced from the cooking of the seasoned meats containing various condiments such as garlic, onion, pepper, soy sauce, and sesame oil. Concentrations, at the breathing zone of the cook, of volatile organic compounds (VOCs) and aldehydes included in the cooking fumes of seasoned meats were identified. Many chloro- and fluoro-aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and aldehydes, which could be carcinogen suspecting chemicals, were producing from the cooking fumes of the seasoned meats. This study also identified the ventilation efficiencies of the cooking fumes of the six exhaust ventilation systems, which were widely being used in the general apartments, houses, and small-food factories. For a comparison of the ventilation efficiencies of the systems, acetaldehyde was chosen as a marker pollutant and its concentrations at the breathing zone of the cook were identified. The laboratory fume hood showed the best ventilation efficiency of the six ventilation systems studied, and then the lateral hood ventilation and the down draft ventilation followed the laboratory fume hood. Finally, this study identified that both a wall factor nearby pollutant sources and a distance factor between the hood face and pollutant sources should be also considered for an effective local exhaust ventilation system design.