• 해양환경안전학회지
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• 제22권5호
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• pp.583-592
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• 2016

해상에서는 UN산하 IMO(International Maritime Organization, 국제해사기구)는 선박에서 배출하는 $CO_2$량을 2030년까지 30 %까지 줄이는 것을 목표로 설정하고 있다. 본 연구는 이러한 상황에 대응하고 친환경기술의 개발을 목표로 선박용 내연기관에서의 폐열을 이용하는 열전발전시스템 개발에 최종목표를 두고, 본 논문에서는 선박용 열전발전시스템 개발에 앞서 기초 열해석을 실시하고 분석하였다. 그 결과 다음과 같은 열전발전시스템의 효율향상에 관한 유효한 방법을 얻어 낼 수 있었다. 1) 고온측 열원과 모듈간 온도차를 줄여 모듈의 온도차를 늘리는 것으로 열전발전시스템의 효율이 8.917 %로 향상되는 것을 알 수 있었다. 2) 외부부하저항의 변화에 따른 시스템 효율은 약 6 %로 그 변화폭이 크게 발생하지 않는 것을 확인할 수 있었다. 3) 동일 계산 조건에서 방형관의 재질이 스테인레스인 경우의 시스템 효율이 8.707 %로 두랄루민(8.605 %), 동(8.607 %)보다 높을 것을 확인할 수 있었다.

• 한국자동차공학회논문집
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• 제16권3호
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• pp.87-93
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• 2008

The $CO_2$ air conditioning system installed in fuel cell vehicles could be used either for stack cooling or for cabin cooling, and thus was used for the stack cooling when additional stack heat release was required over a fixed radiator capacity for high power generation. This study investigated the performance of the stack cooling system using $CO_2$ air conditioner at various operating conditions. Also, the heat releasing effectiveness and mutual interference were analyzed for the stack cooling system using an air conditioner and compared with the conventional radiator cooling system with/without cabin cooling. The heat release of the stack cooling system with the aid of $CO_2$ air conditioner increased up to 36% more than that of the conventional radiator cooling system with cabin cooling. Furthermore, the heat release of the stack cooling system using $CO_2$ air conditioner increased more by 7% than that of the conventional radiator cooling system without cabin cooling.

• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.129-137
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• 2012

This thesis introduced an azimuth tracking prismatic daylighting system. The system improved several issues of the previous passive prismatic daylighting system: low efficiency at sunrise and sunset, glare effect and polarized. The system was developed to track the movement of sun with azimuth tracking device, and it has its own power from the attached solar cells. We compared the with previous passive one in terms with system efficiency and daylighting factors(DF).

• 설비공학논문집
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• 제27권10호
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• pp.544-551
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• 2015

This study was conducted to determine the LCC of apartment complexes with district heating and a cogeneration system. For the purpose of analyzing LCC according to the size of the apartment complex, 500, 1,500, and 4,000-unit model apartments were selected. Analysis was performed on the design of the heating system and the life cycle cost including total construction cost, maintenance and operation cost for the duration of the project period (15 years). According to the calculated results, 1) The initial cost of the cogeneration system for 500, 1,500, and 4,000-unit apartments is higher than that of the district heating system by 20%, 13%, and 12%, respectively. 2) In the case of the cogeneration system, the payback period by electric generation was found to be 5.21, 4.92 and 4.47 years, and saving cost was calculated to be 29 billion won, 94 billion won and 262 billion won after the payback period for 500, 1,500, and 4,000-unit apartments, respectively. 3) The LCC values of the cogeneration system were 1.12, 1.07 and 1.06 times larger than those of the district system according to the size of the apartment complex. In this study, the district heating system was found to be more efficient than the cogeneration system in terms of LCC reduction. 4) District heating is affected by fuel bills, so energy efficiency should be improved through recovering waste heat (incineration heat, etc.). Also, district cooling should be provided according to heat use to keep the temperature high in winter and low in summer.

• 한국지열·수열에너지학회논문집
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• 제3권2호
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• pp.25-30
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• 2007

The final energy consumption in the building sector in Korea represents almost 20% of the total energy consumption. Besides, Space heating and hot water generation in Korea are based on fossil fuels, with a serious environmental impact. This study describes thermal performance of heating demonstration system using close-loop ground source heat pump installed at Korean minjok leadership academy. The results of the experimental study, it retrieve the investment cost for 3years 8months and reduction amount of $CO_2$are 293,900 $kgCO_2$.

• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.76-83
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• 2008

New and more efficient propulsion systems are required for LNG carriers. One of the proposed systems is a combination of a gas turbine with a heat recovery steam generator. This system constitutes a novel approach, which needs to be analyzed by system analysis and risk assessment to compensate for the lack of field experience. Of specific concern is the high pressure fuel supply system. This paper describes the dispersion and fire analysis performed to identify for safety and design improvement of proposed system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.123-126
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• 2005

Recently, because of the depletion of fossil fuels and the environmental pollution by using fossil fuels and harmfulness of atomic power plants. the interests concerning new and renewable energy resources are rising increasingly. And of all new and renewable energy sources the PV generation systems are recognized as the most useful and desirable renewable energy source in allowance for installation conditions. In this development, the 3kWp photovoltaic power generation system is realized to verify the performance of the 3kWp PCS developed by Hyundai Heavy Industries Co. (HHI). The photovoltaic array used in this system is composed of 60 modules of 50Wp capacity. The developed system is tested as procedures and items of test regulation recognized by governmen and the experimental results show the excellent electrical characteristics. Now, the 3kWp PCS developed is installed in the PV model house built in HHI plant and is being tested for practical use commercialization.

• 한국멀티미디어학회논문지
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• 제23권9호
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• pp.1171-1180
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• 2020

The number of the PV systems installed in south korea has been gradually increasing. Interest of operation & management of PV System is rising up as PV System installation trends to increase. The vital function of operation & management is the monitoring system. Most monitoring systems are only available for equipment of suppliers and manufacturers. In this study, a monitoring system was implemented to support multi-domain equipment (inverter, junction box, water distribution board, environmental sensors) that are not limited to specific manufacturers. Monitoring system includes a visualization function, which makes it easy for users to check the power generation and the operation status of the equipment of PV System. In the future, this monitoring system will be utilized as an operation & maintenance foundation element in the PV system industry.

• 한국멀티미디어학회논문지
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• 제18권10호
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• pp.1231-1240
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• 2015

Nowadays, in islands where electricity should be provided autonomously, stand-alone microgrid technologies using renewable energy such as sunlight generation and wind power generation come into wide use. The microgrid electricity generation using renewable energy is greatly affected by the natural environment of a site. In order to maintain stable electricity supply for fluctuating electricity generation due to natural environment, the energy management via EMS is positively necessary. In existing stand-alone microgrid EMS, system operation logic is not changeable flexibly because compiled or builded codes are released into the EMS of a site, respectively. In this paper, we designed a flexible operating script-based microgrid EMS Framework for various sites and applied it to some island sites. We could confirm its usability.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.196-197
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• 2010

This paper investigates a high performance converter topology for hydrogen gas generation electrolysis system. The proposed converter topology consists of full-bridge inverter, medium frequency transformer, and diode rectifier. Hydrogen gas generation electrolysis process considered in the paper is analyzed and characterized by its equivalent circuit. The electrolysis cell is modeled as effective resistance, capacitance, inductance, and internal emf voltage source. The proposed converter topology provides enhanced efficiency of hydrogen gas generation process under the operating condition of dc output voltage with high frequency ripple on it. The high performance operation of proposed converter is confirmed through the simulation with the electrolysis cell considered in the equivalent circuit model.