• Title/Summary/Keyword: Air and Gas

Search Result 4,822, Processing Time 0.035 seconds

An Economic Analysis of the Natural Gas Air-conditioning (가스냉방의 경제성 분석)

  • Gim, Bong-Jin;Park, Yearn-Hong
    • IE interfaces
    • /
    • v.11 no.1
    • /
    • pp.207-214
    • /
    • 1998
  • Since the natural gas air-conditioning not only increases the base load of the gas company but also decreases the summer peak load of the electricity company, it is considerded as an efficient demand-side management program. This paper suggests the economic evaluation method of the gas air-conditioning program from the perspectives of the participants, the pipeline gas company, the local distribution company, the electricity company, and the total resources. The absorption type gas air-conditioning/space-heating is selected as a case study to illustrate the economic analysis of the natural gas air-conditioning.

  • PDF

Real-time Air Quality Monitoring System Based on Wireless Network (무선네트워크기반 공기질 실시간 모니터링 시스템)

  • Paik, Seung Hyun;Lee, Jun Yeong;Jung, Sang Woo;Park, Hong Bae
    • IEMEK Journal of Embedded Systems and Applications
    • /
    • v.11 no.3
    • /
    • pp.143-151
    • /
    • 2016
  • In this paper, a real-time air quality monitoring system based on wireless network is designed and implemented for industrial park or multiuse facilities. The existing gas detector is high price and hard to apply the remote monitoring system. On the other hand, demand for air quality monitoring is increasing because of industrial gas accident, air pollution, and so on. In Korea, indoor air regulation was established by law. According to indoor air regulation, CO2, CO, and NO2 are important gases as the air quality standard. So we study the gas detector for indoor air quality and the wireless network system. The wireless network consist of sensor network and WCDMA to apply various place. To verify the performance of the implemented gas detector, the gas measurement experiment is performed in laboratory environment by using the realized gas detecting wireless sensor node. And we evaluate the experiment results.

Gas Removal Characteristics of Air Clean System Applying a Magnetic Field (자계가 인가된 공기청정장치의 가스 제거 특성)

  • Shin, Soo-Youn;Moon, Jae-Duk
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.5
    • /
    • pp.921-925
    • /
    • 2007
  • Gas removal characteristics of an air clean system, consisted of a filter and a nonthermal discharge plasma reactor with a magnetic field, have been investigated with emphasis on the enhancing gas removal efficiency of the applied magnetic field. It is found that the magnetic field influenced significantly to the corona discharge characteristics, decreasing the corona onset voltage and increasing the corona current. As a result, the proposed air clean system with the magnetic field showed the higher removal efficiency of the gas (e.g., trimethlyamine) than that of without the magnetic field. This would be because the magnetic field applied to the discharge plasma reactor of the air clean system can elevate the corona characteristics, and activate the generation of ozone, thus the removal efficiency of the gas was concurrently enhanced. This reveals that the proposed air clean system with the magnetic field could be used as an effective means of removal an indoor pollutant gas.

Temperature Distributions inside a Space Heater for Greenhouse (I) - Temperature Characteristics with Heating Oil - (시설원예용 온풍난방기내의 온도분포에 관한 연구 (I) - 난방유 사용시 온도특성 -)

  • 서정덕;김종진;최규성;신창식;노수영
    • Journal of Biosystems Engineering
    • /
    • v.24 no.4
    • /
    • pp.335-342
    • /
    • 1999
  • Air and flue gas temperature distributions in the space heater for greenhouse were measured to develop a thermal design technology for the space heater. Also, the characteristics of the fan supplying air to the space heater were investigated. The temperature of the flue gas inside the flue gas tube was linearly decreased as the lenght of than those of the flue gas with the oxygen concentration of 8.25% at the last exit of the second flue gas tube. Thus, the operating efficiency of the space heater could be increased with low air ratio decreased exhausting gas temperature and saved the energy consumption with decreased excess air flow. The temperature of the air supplied by fan was increased slowly around the first flue gas tube, meanwhile, increased sharply around the second flue gas tube due to large LMTD (Logarithmic Mean Temperature Difference) at the first flue gas tube than which of the second flue gas tube.

  • PDF

Development of High Sensitive Integrated Dual Sensor to Detect Harmful Exhaust Gas and Odor for the Automotive (악취분별능력을 가진 자동차용 고기능 듀얼타입 집적형 유해가스 유입차단센서 개발)

  • Chung, Wan-Young;Shim, Chang-Hyun
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.13 no.7
    • /
    • pp.616-623
    • /
    • 2007
  • A dual micro gas sensor array was fabricated using nano sized $SnO_2$ thin films which had good sensitivities to CO and combustible gases, or $H_2S$ gas for air quality sensors in automobile. The already existed air quality sensor detects oxidizing gases and reducing gases, the air quality sensor(AQS), located near the fresh air inlet detected the harmful gases, the fresh air inlet door/ventilation flap was closed to reduce the amount of pollution entering the vehicle cabin through HVAC(heating, ventilating, and air conditioning) system. In this study, to make $SnO_2$ thin film AQS sensor, thin tin metal layer between 1000 and $2000{\AA}$ thick was oxidized between 600 and $800^{\circ}C$ by thermal oxidation. The gas sensing layers such as $SnO_2$, $SnO_2$(pt) and $SnO_2$(+CuO) were patterned by metal shadow mask for simple fabrication process on the silicon substrate. The micro gas sensors with $SnO_2$(+Pt) and $SnO_2$(CuO) showed good selectivity to CO gas among reducing gases and good sensitivity to $H_2S$ that is main component of bad odor, separately.

Study on the control of fuel-air ratio ofgas swirl burner (가스 스월버너의 공연비 제어에 관한 연구)

  • Kim, I.K.;Kim, Y.S.;Kim, Y.H.;Kim, K.S.;Kim, J.W.
    • 한국연소학회:학술대회논문집
    • /
    • 1999.10a
    • /
    • pp.129-138
    • /
    • 1999
  • In this paper, our main issue is that establishing the control procedure of continuous gas flow rate according to combustion fan RPM. For this, first, we decide the optimum operating condition of gas swirl burner through analysis of combustion characteristics - thermal efficiency, combustion efficiency and exhaust gases such as CO, $CO_{2}$, $O_{2}$, $NO_{x}$ and THC. Second, fuel gas flow rate of gas valve is decided with considering excess air ratio and combustion fan RPM is decided by the target of combustion air flow rate. Finally, experimental operating equation is acquired by regression for gas valve and combustion fan. This equation is the control equation of continuous gas flow rate and always gas flow rate is decided by combustion fan operating RPM.

  • PDF

A Study on Tracer Gas Methodology to Measure Interzonal Airflow Rates (실간환기량 측정을 위한 추적가스 실험방법론에 관한 연구)

  • Han, Hwa-Taik;Cho, Seok-Hyo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.21 no.11
    • /
    • pp.606-612
    • /
    • 2009
  • Interzonal air movements are important to characterize overall ventilation performance of complicated multi-zone buildings. Tracer gas techniques are widely used to measure ventilation rates, ventilation effectiveness, and interzonal air movements. Depending on the number of gases used, they are divided into single and multi tracer gas methods. This paper deals with the comparison of the tracer gas methods in measuring air exchange rate between rooms. Experiments have been conducted in a simple two-room model with known airflow rates. In multi-gas procedure, the concentration decays of two tracer gases, i.e SF6 and R134a are measured after simultaneous injections in each room. The single tracer gas method is also applied by injecting SF6 gas with a time lag between two rooms. The data reduction procedures are developed to obtain the interzonal airflow rate using the matrix inversion, and various data manipulation methods are tested, such as data shift, interpolation, and smoothing. Uncertainty for each airflow rate is investigated depending on the parameters based on the setting values.

An Experimental Study for Reducing the Exhaust Hydrocarbon Emission at SI Engine Using Timed Secondary Air Injection (2차 공기 분사에 의한 스파크 점화 가솔린 엔진의 배기 Hydrocarbon 저감에 관한 실험적 연구)

  • 심현성;김세준;정석호
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.7 no.7
    • /
    • pp.104-112
    • /
    • 1999
  • An experimental study for reducing the exhaust hydrocarbon emission at spark ignition engine using timed secondary air injection is carried out . In this study, secondary air injection timings and durations are controlled to decrease the hydrocarbon emission and to increase exhaust gas temperature at cold and warm-up engine conditions. The hydrocarbon reduction rate and exhaust gas temperature are compared between timed secondary air injection and continuous air injection. The optimum secondary air injection timing for reducing the hydrocarbon emission is at the exhaust valve open timing. At some engine conditions , the hydrocarbon emissions are decreased to 10% of engine raw values and exhaust gas temperatures increase by 20$0^{\circ}C$ with times secondary air injection . Timed secondary air injection has more hydrocarbon reduction rate that continuous secondary air injection except some engine conditions.

  • PDF

Measurement of Minimum Ignition Energy by Electrostatic Discharge for Flammable Ternary Gas Mixtures (3성분계 인화성 혼합가스의 최소점화에너지 측정에 관한 연구)

  • Choi, Sang-Won
    • Journal of the Korean Society of Safety
    • /
    • v.28 no.1
    • /
    • pp.29-34
    • /
    • 2013
  • When flammable gases are mixed with air or oxygen in the explosion concentration range and are ignited by sufficiently large electrostatic discharge energy, they may explode causing severe disaster in workplace. The minimum ignition energy(MIE) of single gas-air mixtures has been already investigated by many research, but the MIE of mixtures of more than ternary gas mixture is not examined yet. The purpose of this study is to investigate the MIE of a ternary gas(methane, ethylene, hydrogen, propane) mixtures experimentally. The results of our experiment show that the ignition of a methane-ethylene-air, methane-hydrogen-air, methane-propane-air, ethylene-hydrogen-air, ethylene-propane-air and hydrogen-propane-air mixture due to electrostatic discharge energy primarily depends on that the mixture: the MIE decreases gradually with the increase of having the lower MIE than other mixture ratio in the normal atmospheric pressure.

Breakdown Characteristics of Dry Air under 170[kV] GIB (170[kV] GIB 내에서 건조공기(Dry Air)의 절연파괴 특성)

  • Han, Ki-Son;Yoon, Jin-Yul;Ju, Hyung-Jun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.24 no.10
    • /
    • pp.136-142
    • /
    • 2010
  • In this paper, we changed $SF_6$ insulation gases used already in the GIB(Gas Insulated Bus, gas insulated busbar) of switching appliances of power grid 170[kV] GIS(Gas Insulated Switchgear, Gas Insulated Switchgear) with green insulation dry air gases and studied dielectric breakdown voltage characteristics by the AC voltage withstand test. Withstand test AC voltage applied to the standard KEPCO's 170[kV] GIB with dry air insulation and and the equivalent of dry air and $SF_6$ gas were examined. Breakdown voltage of dry air, using an expression of the experiments were calculated and AC Withstand criterion of dry air insulation for the AC voltage test was derived. Using the criterion, dry air gases can be used instead of the $SF_6$ gas was confirmed in the factory acceptance test at 170[kV] GIB.