• Journal of the Korean Society of Visualization
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• v.21 no.2
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• pp.45-54
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• 2023

In the present study, we propose new type of a spinning disk reactor(SDR) with high performance and very convenient structure to make a large scale equipment from lab-scale than the conventional one. A split-disk experimental equipment, based on new type of spinning disk reactor, has been developed to generate an energy to break a bulk of injected gas into smaller gas bubble. Several cases of an experimental observation make it to confirm that a bulk of injecting gas could be continuously break into smaller bubbles. It shows the feasibility to make a scale-up of SDR by using the characteristic of Taylor-Proudman column in rotating flow. A theoretical study on single phase liquid flow is given to predict a liquid induced shear stress, which make the present study to be self-containment.

• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.527-530
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• 2001

In this paper, the basic characteristics of flat fluorescent lamp using ultraviolet generate from gas discharge and powder type electrolyminescent display(P-ELD) using a phenomenon of the light emission eaused by the electrical field applied to phosphor are studied. The lamp is a simple structure with insulator layer, phosphor layer, and gas gap. Current(displacement current + discharge current) in flat fluorescent lamp using.

• IE interfaces
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• v.9 no.3
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• pp.283-297
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• 1996

The 'flat-bar' is a stiffener which is a component of ships. It is basically a long rectangle and has 'end-cut' shapes at both sides. The paper describes a fast nesting algorithm of the flat-bar, and a procedure to generate cutting path of gas/plasma torch, which is operated by a NC (numerically controlled) gas/plasma cutting machine. Proposed procedures are written in C-language and executable on VAX machine with Open VMS operating system.

• Journal of the Korean Institute of Gas
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• v.5 no.2 s.14
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• pp.9-13
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• 2001

A complete spectrum of risk assessment including qualitative and quantitative approaches were performed for the POSCO's Batch Annealing Furnace (BAF) gas systems. The purpose of BAF is to enhance the quality of steel by annealing it with either hydrogen/nitrogen mixture gas or pure hydrogen gas. Number of gas leak scenarios were identified to generate frequency of their occurrences. With the hypothetical accident scenarios given, fire/explosion impact studies were performed to estimate magnitude of significant consequences. Several different indices were also presented from which practical safety improvement action items could be established.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.675-678
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• 2006

We developed a Flat Fluorescent Lamp(FFL) with a high luminance by using the same discharge mode as PDP. Our FFL has the simple and unique structure where the glass substrates are used as dielectric layers. The panel has a striped line shape of 7 inch diagonal size. The Xe-Ne-He mixture gas was used to generate the plasma, and the gas discharge characteristics under both total gas pressure and partial gas pressure were investigated. The panel showed a maximum high luminance $7,270cd/m^2$ under bias of 20KHz pulse of 3KV.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.345-350
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• 2008

The present study has been conducted to develop a heat recovery system for a 1 MW class gas engine based cogeneration system. In the cogeneration system, heat is recovered from two parts, which are jacket water and exhaust gas. The heat from the jacket water is recovered by a plate type heat exchanger and used for the room heating and/or hot water supply. The heat from the exhaust gas is used to generate steam. For both of the heat recovery devices, 1/5 scaled tests are performed and the data are compared to the conventional correlations for the design.

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.59-65
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• 2008

Among the various cases of fire accident, gas accident which is roost essential have a lot of forms and causes. The quantity consumed of gas is increasing because of increment of gas-using families and variations of gas machinery. The quantity consumed of gas in 2007 was 35078 tons and the average rate of increasement was 9.4%. The amount of gas accident was on the peak at 1995 when 557 accidents occurred in a year. In 2007, 123 gas accidents was occurred and the average rate of diminution was 11.5%. Accidents by LP gas took 80% of the whole accident and city gas and high pressure gas took 20%. In case of LP gas, accidents were usually occurred because of lack of blocking after the removal of gas machinery and moveable butane burner. Especially, the accidents cause by carelessness of a provider is increasing. Gas accidents which generate damage of human life and property, are caused by users' carelessness, providers' carelessness, inferiority of structure and old products. In this thesis, We will classify the gas accidents. Furthermore through the classification of accidents by forms, causes and regions, this thesis going to be a reference to understand and prevent the accidents.

• The KSFM Journal of Fluid Machinery
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• v.19 no.6
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• pp.26-33
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• 2016

Combined heat and power (CHP) system is one of the power generation system which can generate both electricity and heat. Generally, mid-size and big-size CHP plant in Korea generate electricity from gas turbine and steam turbine, then supply heat from exhaust gas. Actually, CHP can supply heat using district heater which is located at low pressure turbine exit or inlet. When the district heater locates after low pressure turbine, which called back pressure type turbine, there need neither condenser nor mode change operating control logic. When the district heater locates in front of low pressure turbine or uses low pressure turbine extraction steam flow, which calls condensing type turbine, which kind of turbine requires condenser. In this case, mode change operation methods are used for generating maximum electricity or maximum heat according to demanding the seasonal electricity and heat.

• Journal of Power Electronics
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• v.13 no.5
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• pp.841-853
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• 2013

An application of doubly-fed induction generator (DFIG), which is one of adjustable speed generators, to a gas engine cogeneration system has been investigated. To operate during a blackout as an emergency power supply is one of important roles for the gas engine cogeneration system. However, the DFIG requires initial excitation for startup during a blackout because the DFIG has no excitation source. In this paper, we propose the "blackout start" as a new excitation method to generate a rated voltage at the primary side during a blackout. In addition, a stand-alone operation following a blackout has been investigated by using experimental setup with a real gas engine. Power flows in the generating set with the DFIG at the stand-alone operation have been investigated experimentally. Experimental investigation of the power flow suggests that the generating set with DFIG has optimal speed in minimizing whole system losses.