• Title/Summary/Keyword: Air & gas

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Breakdown Characteristics of Dry Air under 362 kV GIB (362 kV GIB 내에서 건조공기의 절연파괴 특성)

  • Han, Ki-Son;Ju, Hyung-Jun;Yoon, Jin-Yul;You, Hong-Geun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.10
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    • pp.804-808
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    • 2010
  • In this paper, we studied the dielectric breakdown voltage characteristics by the AC withstand voltage test on using green insulation dry air instead of $SF_6$ insulation gas used in the GIB (gas insulated bus) of 362 kV GIS (gas insulated switchgear). The AC withstand voltage test applied to the standard KEPCO's 362 kV GIB with dry air insulation, and the equivalence of dielectric breakdown voltage for dry air and $SF_6$ gas were examined, and the empirical formulas of dielectric breakdown voltage for dry air were calculated, and the criterion of AC withstand voltage test for dry air insulation was derived. Using the criterion, dry air can be used instead of $SF_6$ gas for 362 kV GIB in the factory acceptance test was confirmed.

Gas and particle removal characteristics of a novel electrostatic precipitation type air cleaner using an activated carbon filter as an electrode (활성탄 섬유 필터를 전극으로 활용한 정전 방식의 공기정화장치의 가스 및 입자 제거 특성 분석)

  • Lim, Gi-Taek;Kim, Yong-Jin;Han, Bangwoo;Woo, Chang Gyu;Shin, Weon Gyu;Kim, Hak-Joon
    • Particle and aerosol research
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    • v.14 no.1
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    • pp.9-16
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    • 2018
  • We have developed an electrostatic precipitation (ESP) type air cleaner for indoor air quality and investigated its performances regarding CADR (Clean air delivery rate), single-pass efficiency and gas removal efficiency. The ESP air cleaner used an ACF (Activated carbon fiber) filter for gas removal and the ACF as a high voltage electrode for particle removal. The ESP air cleaner was tested in a chamber with the volume of $1m^3$ regarding CADR and gas removal efficiency. The applied CADR area of the ESP was $1.8m^2$. Gas removal efficiency was tested with 3 gases (Acetaldehyde, Acetic acid, Ammonia). As the results of the gas removal efficiency, the ESP air cleaner shows the removal efficiencies of 90, 98 and 85% for acetaldehyde, acetic acid and ammonia, respectively.

Heat Recovery Characteristics of the Exhaust Heat Recovery System with Heat Pipe Unit Attached to the Hot Air Heater in the Greenhouse (히트파이프를 이용한 온풍난방기 배기열회수 시스템의 열회수 특성)

  • Kang, K. C.;Kim, Y. J.;Ryou, Y. S.;Baek, Y.;Rhee, K. J.
    • Journal of Biosystems Engineering
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    • v.26 no.5
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    • pp.441-448
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    • 2001
  • Hot air heater with light oil combustion is used as the most common heater for greenhouse heating in the winter season. However, exhaust gas heat discharged to atmosphere through chimney reaches up to 10~20% of total heat capacity of the oil burred. In order to recover the heat of this exhaust gas and to use for greenhouse heating, the heat pipe type exhaust heat recovery system was manufactured and tested in this experiment. The system consisted of a heat exchanger made of heat pipes, ø15.88${\times}$600mm located in the rectangular box of 675(L)${\times}$425(W)${\times}$370(H)mm, an air suction fan and air ducts. The number of heat pipe was 60, calculated considering the heat exchange amount between exhaust gas and air and heat transfer capacity of a heat pipe. The working fluid of heat pipe was acetone because acetone is known for its excellent heat transfer capacity. The system was attached to the exhaust gas path. According to the performance test it could recover 53,809 to 74,613kJ/h depending on the inlet air temperature of 12 to -12˚at air flow rate of 1.100㎥/h. The temperature of the exhaust gas left the heat exchanger dropped to 100$^{\circ}C$ from 270$^{\circ}C$ after the heat exchange between the suction air and the exhaust gas.

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A Study on the Calculation Formulae of Required Air and Burning Gas Amount of Heavy Fuel Oil (중유의 연소에 필요한 소요공기량과 발생가스량의 산식에 관한 연구)

  • 이우환
    • Journal of Advanced Marine Engineering and Technology
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    • v.6 no.1
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    • pp.34-40
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    • 1982
  • The characteristics of typical 17 kinds of fuel oils are studied to fine the calculation formulae for the required amount of air and the combustion gas amount. 1) The author's calculation formulae are as follows; (1) Theoretically required amount of air (2) Theoretical amount of combustion gas 2) Theoretical amount of the required air in combustion and combustion gas of fuel oils are always estimated less with Rosin's formula than with author's one. 3) Theoretical amount of the required air and the amount of combustion gas of fuel oils are more reasonable with author's formula than Rosin's one in comparison with results of actual analysis.

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Performance Analysis of an Inert Gas Generator for Fire Extinguishing

  • Kim, Su-Yong;Arkadiy F. Slitenko
    • 연구논문집
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    • s.29
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    • pp.5-15
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    • 1999
  • Present study deals with performance analysis of an inert gas generator (IGG) which is to be used as an effective mean to suppress the fire. The IGG uses a turbo jet cycle gas turbine engine to generate inert gas for fire extinguishing. It is generally known that a lesser degree of oxygen content in the product of combustion will increase the effectiveness of fire suppressing. An inert gas generator system with water injection will bring advantages of suffocating and cooling effects which are considered as vital factors for fire extinguishing. As the inert gas is injected to the burning site, it lowers the oxygen content of the air surrounding the flame as well as reduces the temperature around the fire as the vapour in the inert gas evaporates during the time of spreading. Some important aspects of influencing parameters, such as, air excess coefficient. $\alpha$, compressor pressure ratio, $ pi_c$, air temperature before combustion chamber, $T_2$, gas temperature after combustion chamber, $T_3$, mass flow rate of water injection, $M_w$, etc., on the performance of IGG system are investigated. Calculations of total amount of water needed to reduce the turbine exit temperature to pre-set nozzle exit temperature employing a heat exchanger were made to compare the economics of the system. A heat exchanger with two step cooling by water and steam is considered to be better than water cooling only. Computer programs were developed to perform the cycle analysis of the IGG system and heat exchanger considered in the present study.

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Estimation of Air Concentrations of PCBs using Passive Air Samplers (PAS) and a Gas/particle Partition Model (Passive Air Sampler (PAS)와 기체/입자 분배모델을 이용한 대기 중 PCB 농도 산정)

  • Baek, Song-Yee;Choi, Sung-Deuk;Chang, Yoon-Seok
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.6
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    • pp.734-743
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    • 2007
  • Polyurethane foam-disk passive air samplers (PAS) were deployed in a southern area of Korea for three months. The target compounds were 12 coplanar polychlorinated biphenyls (PCBs). The congener profiles measured in this study were the same as those in ambient air and emission gas from the incinerator. A gradient of the total PCBs in different regions (industrial>residential>rural) was observed, suggesting the industrial complex may be an important source of coplanar PCBs. In general, only gas-phase compounds are mainly sequestrated by PAS. In order to estimate the concentration of particle-phase PCBs, a gas/particle partition model was used. A combined result (gas+particle-phase PCBs) was compared with previous results, indicating that the level of coplanar PCBs in our study area is comparable to those in other urban sites in the world. The validation of this method for estimating the total concentration is required through additional backup studies.

Research about room air quality of department store underground parking lot (백화점 지하 주차장의 실내 공기질에 관한 연구)

  • Kim Ki-Tae;Yang Sung-Su;Son Bu-Soon;Jeon Young-Taek;Jang Bong-Ki;Lee Jong-Dae
    • Journal of environmental and Sanitary engineering
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    • v.21 no.1 s.59
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    • pp.44-51
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    • 2006
  • This study was conducted to investigate air quality in the underground parking lot of department store. Sampling sites were selected to the three sites in one department store. Measuring instrument started from November 3rd, 2005 to November 9, 2005. Target air quality parameters include a number of criteria pollutants such as NOx, $O_3$. The purpose of this study was to find out the present condition of indoor air quality in underground parking space of department store. Through the field measurement, the current situation and the behavior of contaminants were investigated and then was compared with the advice standards. The result of this study was as follows; The Average density of NOx gas and $O_3$ gas was maintained below the indoor air advice standards. The Average density of NOx gas and $O_3$ gas was highly measured during the weekend than during the week day. Average density of NOx gas and $O_3$ gas was highly measured at daytime than that of afternoon. Average density of NOx gas was highly measured in the center area than the other area. Average density of $O_3$ gas was highly measured at the entrance than the other area. NOx gas concentration was maintained below 0.3ppm, an average for 1 hours, as defined in the parking space law. $O_3$ gas concentration was maintained below 0.08ppm, an average for 1 hours, as defined in the parking space law.

Combustion Emission Characteristics on the Effect of Secondary Air Injection in Model Gas Turbine Combustor (모형 가스터빈 연소기의 2차공기 주입에 따른 연소배출특성)

  • 김규성;임경달;이도형
    • Journal of Ocean Engineering and Technology
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    • v.14 no.3
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    • pp.84-89
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    • 2000
  • The purpose of this study is to investigate the combustion emission characteristics by the effect of secondary air injection and variation of the excess air ratio in combustion field of model gas turbine combustor. For this purpose, mean temperature, CO, $CO_2$, $O_2$ and HC concentrations were measured by changing excess air ratio and secondary air injection. As a result of this study, mean temperature was decreased and CO, HC emission increased by increasing the excess air ratio of secondary air. Therefore, this results showed the secondary air injection effected strongly on the flame structure and combustion emission characteristics.

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Effects of Secondary Air Injection in Combustion Field of Model Gas Turbine Combustor (모형 가스터빈 연소기에서 2차공기 주입이 연소장에 미치는 영향)

  • 김규성;임경달;이동형
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.04a
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    • pp.171-176
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    • 2000
  • This purpose of this study is to investigate the combustion emission characteristics on the effect of secondary air injection in combustion field of model gas turbine combustor changing excess air ratio. For this purpose, meantemperature, CO, CO2, O2 and HC concentration were measured by changing excess air ratio and secondary air injection. As a result of this study, meantemperature, CO2 emission was decreased and CO emission increased by increasing the excess air ratio of secondary air. therefore, This paper showed the effect of Secondary air injection on flame structure, combustion emission characteristics.

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