• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.910-915
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• 2009

For large reciprocating compressors in parallel operation, an analytical study has been carried out on the gas pulsation in associated discharge piping lines. Since the pressure pulsation at a valve, valve dynamics, and the gas flow rate through the valve are interrelated, affecting one another, these need to be solved simultaneously. Acoustic transfer matrix method, which relates acoustic pressure and velocity at one location to those at another location, has been adopted to calculate the effect of the gas flow at one valve location on the gas pulsation at other valve locations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.465-468
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• 1995

The gas-insulated switchgear(GIS) has made high-reliability, high-safety, compact substations possible by using $SF_6$ gas. They are likely to be further developed toward higher voltages and targer capacities, along with greater compactness and lower cost. Although $SF_6$ gas has excellent insulation performance, breakdown voltages are reduced by the conducting particles. Thus, extensive studies have been made on the breakdown characteristics of $SF_6$ gas in particle contaminated conditions. Experiments were carried out for fired particle and free particle in a coaxial electrode system with DC and AC voltages. This paper represents the experimental results of the processes involved in electrical breakdown in compressed $SF_6$ gas, where breakdown is initiated by conducting particles.

• Journal of Advanced Marine Engineering and Technology
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• 제24권6호
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• pp.128-139
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• 2000

Environmental concerns and shortage of petroleum have promoted considerable interest in the use of alternate fuels in stationary diesel engine. In this study, a heavy-duty, intercooler-turbocharged 6-cylinder stationary diesel engine was converted into stationary gas engine fueled with propane or natural gas for the cogeneration plants. One of the most important factors in the combustion features of a stationary gas engine is the fuel composition and operating parameters in terms of compression ratio, spark advance, and engine loads. Experiments with different fuel gas and load conditions were carried out with combustion pressure analysis and NOx measurement. Combustion analysis based on P-$\theta$ diagrams was also investigated by means of combustion duration and cycle variation. Compression ratio is 10.0 and ignition timing is set by using the gasoline setting as a base line and advanced toward BTDC. The results show that fuel composition and spark advance have dominant effects on combustion and NOx characteristics at operating conditions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.323-324
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• 2005

To found out the degradation characteristic of transformer insulation, insulation materials and electrodes are deposited into transformer oil. They used to heated and make flashover. Due to the thermal and electrical stress added to insulation materials, the density of carbon dioxide and hydrogen included in transformer oil was increased. The gas density can measured by using the gas density detection equipment of gas sensor and air circulation method.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1995년도 제2회 KOSCI Workshop
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• pp.105-121
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• 1995

The objective of this study is to find out the design data for gas burner with an axal and radial type nozzles. The design parameters are chosen as the stabilizer type, the jet hole size of gas nozzle, the distance between gas nozzle and stabilizer, the size of stabilizer and the hole size of stabilizer, the stabilizer type with or without air swirler, the angle of swirler. For the experimental test combustor sizing ${\phi}1.3m{\times}L4.5m$ is designed and manufactured, in which the set up of power diagram, the exhaust gas analysis, blow-off test, the flame temperature and the direct photography are performed.

• 연구논문집
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• 통권30호
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• pp.33-42
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• 2000

We must stabilize quickly increasing waste matters in urban life and livestock industry. Biogas including landfill gas and digester gas is byproduct of anaerobic decomposition of organic waste matter and contains 40%-70% methane, which can be used for energy purposes. Utilization of biogas reduce the emission of methane into the atmosphere to minimize greenhouse effect and the carbon dioxide (CO2) emitted when biogas is converted to energy has been taken out of the atmosphere by growing plant. Recently, bioenergy is world-widely noticeable as all contributing to the greenhouse effect. This paper presents development process of a biogas engine for cogeneration system and results of application to digester gas and landfill gas in site. The biogas engine is a dual fuel engine operated on biogas with a diesel pilot. At present, the engine can substitute biogas for diesel fuel up to 85%. but it can be said that there is a possibility of improvement in performance.

• 대한기계학회논문집B
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• 제29권3호
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• pp.384-389
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• 2005

Experimental study of variation of exhaust gas temperature was carried out with the changes of spark timing and exhaust valve timing during the cold start operation of an SI engine. To investigate the effects of these variables on combustion stability, cylinder pressure and exhaust gas temperature were measured and analyzed. Experimental results showed that exhaust gas temperature increased when spark and exhaust valve timings were retarded from the baseline cases. However, combustion stability during cold start deteriorated under the retarded conditions. To increase exhaust gas temperature for fast warmup of catalysts while maintaining combustion stability, an optimal condition for spark and valve timing retard should be appied for the cold start period.

• 설비공학논문집
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• 제22권2호
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• pp.97-103
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• 2010

For large reciprocating compressors in parallel operation, an analytical study has been carried out on the gas pulsation in associated discharge piping lines. Since the pressure pulsation at a valve, valve dynamics, and the gas flow rate through the valve are interrelated, affecting one another, these need to be solved simultaneously. Acoustic transfer matrix method, which relates acoustic pressure and velocity at one location to those at another location, has been adopted to calculate the effect of the gas flow at one valve location on the gas pulsation at other valve locations.

• Transactions on Electrical and Electronic Materials
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• 제17권4호
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• pp.204-207
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• 2016

Experimental study of UV-irradiated O₂/H₂ gas phase cleaning for PMMA (Polymethylmethacrylate) removal is carried out in a load-locked reactor equipped with a UV lamp and PBN heater. UV enhanced O₂/H₂ gas phase cleaning removes polymethylmethacrylate (PMMA) better at lower process pressure with higher content of H₂. O₂ gas compete for UV (184.9 nm) absorption with PMMA producing O₃, O(¹D) and lower dissociation of PMMA. In our experimental conditions, etching reaction of PMMA at the substrate temperature between 75℃ and 125℃ had activation energy of about 5.86 kcal/mol indicating etching was controlled by surface reaction. Above the 180℃, PMMA removal was governed by a supply of reaction gas rather than by substrate temperature.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.412-414
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• 2006

In this study, an experimental apparatus has been designed and set up to analyze the dissociating phenomena of hydrate in porous rock. Experiments with the depressurization ion scheme have been carried out to investigate the dissociation characteristics of methane hydrates and the productivities of dissociated gas and water. From the experiments, it has been provided a determination of volume of gas produced and the progress of the dissociation front, as a function of time when hydrate is depressurized. Also, it has been investigated the flowing behavior of the dissociated gas and water in porous rock and the efficiency of the production