• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.234-238
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• 2002

Lubricating oil supply system is an essential instrument for safe turbine operation. A lubricating condition may cause the abnormal vibration of turbine. In this paper we have discussed the abnormal vibration of turbine due to lubricating oil. Dusts of the air usually attach to end of the oil deflector and contact particles of the bearing oil. Dusts which were contacted particles of the bearing oil were changed into carbon deposit because of high temperature. therefore, carbon deposits occur abnormal vibration of the turbine when they contact a rotor. So, we have solved this problems through the various maintenance.

• 한국자동차공학회논문집
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• 제12권6호
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• pp.127-134
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• 2004

Three-dimensional numerical investigations are carried out to understand the combustion characteristics inside a DLN(dry low NOx) utility gas turbine combustor during the combustion mode change period by applying transient fuel flow rates in fuel supply system as numerical boundary conditions. The numerical solution domain comprises the complex combustor liner including cooling air holes, three types of fuel nozzles, a swirl vane, and a venturi. Detailed three-dimensional flow and temperature fields before and after combustion mode changeover have been analyzed. The results may be useful for further studies on the unfavorable phenomena, such as flashback or thermal damage of combustor parts when the combustion mode changes.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1998년도 제17회 KOSCI SYMPOSIUM 논문집
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• pp.1-8
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• 1998

Waste combustion above a grate is the core process of incineration systems, stability of which should be guaranteed for emission minimization. However, complicated reactions and heat and mass transfer phenomena make understanding the process difficult. One dimensional bed combustor with a numerical combustion model is utilized to investigate the combustion process of the bed, using cubic wood particles as a simulated fuel. Bed combustion behavior is characterized with apparent flame propagation speed, which has close relationship with air supply rate and chemical and physical characteristics of the fuel. Base on the availability of oxygen, two distinct reaction zone is identified; the oxygen-limited and the reaction-limited zone leading to the extinction by excessive convection cooling. The numerical modeling shows good agreement with the experimental results. The transient bed combustion behavior of local temperature and oxygen consumption rate is adequately reproduced. The numerical model is extended to model the waste bed combustion of a commercial incineration plant, which shows meaningful results as well.

• 한국생산제조학회지
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• 제18권6호
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• pp.690-696
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• 2009

This paper introduces the automatic fine Bituminous Coal injection lance position control method using flame image process. The fine Coal injection lance is used to supply additional heat into the furnace in Mill plant. It injects fine coal into high pressured air flow and produces very heated and high pressured flame. For the such high temperature and pressure, the fine coal injection lance effects not only efficiency of burner but also furnace abrasion. To keep efficient combustion status and to avoid the abrasion, in this paper, the flame is monitored by computer image process. This paper proposes the flame image process method and lance position control according to calculated result for flame image process.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.399-404
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• 2008

Condensing gas boiler units may make a big role for the reduction of energy consumption in heating industries. In order to decrease the energy consumption of a condensing gas boiler unit, the effective control of the system is necessary. In this study, control algorithms of a condensing gas boiler were developed. Control algorithms are composed of the setpoint algorithm and the control algorithm. The setpoint algorithm consists of the supply water temperature setpoint algorithm and the pump setpoint algorithm. The control algorithm consists of the gas valve control algorithm and the blower control algorithm. In order to analyse the performance of control algorithms, dynamic models of a condensing gas boiler system were used. Simulation results showed that control algorithms developed for this study may be practically applied to the condensing gas boiler.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기설비전문위원
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• pp.156-158
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• 2004

In the ATs(Auto-Transformers)-fed AC electric railroad system, the trolley wire with high power is supported with a messenger by the dropper. As the dropper maintains the height of the trolley wire and plays a role in distributing the supply power, it should be stabilized in that an electric and mechanical character accord ins the change of the open air circumstance and constructed easily. Consequently, this paper propose C5111 Sn(3.5$\sim$4.5%) and hexagonal round bolt for the way of the efficient stabilization as a result of the test that the correlation of the Sn content and the change of temperature affect a character of product.

• 한국추진공학회지
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• 제10권2호
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• pp.39-45
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• 2006

로켓 엔진 터보펌프용 터빈은 고온, 고압의 연소가스를 사용하기 때문에 실제 환경에서 성능시험을 수행하기가 매우 어렵다. 따라서 대부분의 경우, 시험에 따르는 위험을 줄이기 위하여 공기를 사용한 시험을 통하여 성능을 평가한다. 본 논문에서는 10 톤급 액체로켓엔진 터보펌프용 터빈에 대한 공기 상사 성능시험에 대하여 기술하였다. 터빈의 공기역학적인 성능을 평가하기 위한 성능시험설비를 구성하였으며, 성능시험설비는 고압공기 공급시스템, 유량측정용 노즐, 시험부, 동력계. 압력조절을 위한 출구 오리피스 그리고 측정 및 제어 시스템으로 구성된다. 본 논문에서는 터빈성능 시험을 위한 상사시험 조건을 결정하는 방법과 시험조건을 조절하는 방법에 대하여 기술하였다. 시험결과, 측정 변수들의 상대 표준오차는 1%이내였으며 측정된 터빈 효율은 해석결과와 2% 이내로 일치하였다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.107.1-107
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• 2003

The fermentation process and subsequent processing determine the efficacy of a bioherbicide propagule. Large batches of biomass of the mycoherbicide agent for white clover, Sclerotium sp.(BWC98-105) was produced in simple liquid fermentator in 5 gallons vessels(Model No. 8087, Dabo Inc., Korea) with oxygen supply(DPH16000, FineTech Inc., Korea) simulating industrial conditions by utilizing commercially available, inexpensive ingredients (10 ％ rice bran), The maximum biomass yield of Sclerotium sp.(BWC98-105) was obtained after 5 days of air pumped incubation at room temperature condition(22-28$^{\circ}C$). By using this simple facility, it could get fragmented or proliferated greatly and attained maximum mycelia biomass. The biomass of mycoherbicide agent consisted of hyphae devoid of spores. Biomass mycelia of the fungus 99％ survival at room temperature after 2 me. A thorough understanding of the effects of fermentation and formulation on viability and virulence is required to guide these processes. After an economical yield level of bioherbicide propagule has been achieved in a fermentation process, formulation becomes a critical factor which influences product efficacy. Because the fermentation must be stopped at a point when virulence/viability are optimum, the live bioherbicide propagule must be stabilized, formulated, and packaged.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.29-33
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• 2004

This paper presents ESPI system for the measurement of thermal expansion coefficient of STS430 up to 1,000$^{\circ}C$. Existing methods, strain gauge and moire have the limitation of contact to object and do not supply the coefficient up to 800$^{\circ}C$. There needs to measure the data up to 800$^{\circ}C$, because heat resistant materials have high melting temperature up to 1,000$^{\circ}C$. In previous studies related to thermal strain analysis, the quantitative results are not reported by ESPI at high temperature, yet. In-plane ESPI and vacuum chamber for the reduction of air turbulence and oxidation are designed for the measurement of the coefficient up to 1,000$^{\circ}C$and speckle correlation fringe pattern images are processed by commercial image filtering tool-smoothing, thinning and enhancement- to obtain quantitative results, which is compared with references data. The comparison shows two data are agreed within 4.1％ blow 600$^{\circ}C$ however, there is some difference up to 600$^{\circ}C$. Also, the incremental ratio of the coefficient is changed up to 800$^{\circ}C$. The reason is the phase transformation of STS430 probably begins at 800$^{\circ}C$.

• Environmental Engineering Research
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• 제21권2호
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• pp.145-151
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• 2016

Biodrying is a pre-treatment method that applies biological and mechanical concepts to drying solid waste. In Malaysia, municipal solid waste (MSW) is unseparated and contains a high level of moisture, making the use of technology such as solid waste burning unsuitable and harmful. MSW containing organic material can be processed naturally until the moisture content of the waste is reduced. This study on MSW biodrying was carried out on a laboratory scale to measure the percent moisture content reduction and to monitor temperature patterns under different ventilation periods. This work was conducted using five biodrying reactors volumes of 50 liters each. Reactors were ventilated for 5, 10, 15, 20 and 30 min every 3 h, with a 3 bar air supply. The duration of this process was 14 days for all samples. The results showed that the optimum ventilation time was 10 min, with an 81.84% reduction in moisture content, and that it required almost half of the electricity cost required for the 20 and 30 min ventilations.