• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.667-672
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• 2023

This study proposes polymer electrolyte membrane fuel cell (PEMFC) based cogeneration system for greenhouse heating and cooling. The main scope of this study is to examine the proposed cogeneration system's suitability for the 660 m²-class greenhouse. A 25 kW PEMFC system generates electricity for two identical air-cooled heat pumps, each with a nominal heating capacity of 70 kW and a cooling capacity of 65 kW. Heat recovered from the fuel cell supports the heat pump, supplying hot water to the greenhouse. In cooling mode, the adsorption system provides cold water to the greenhouse using recovered heat from the fuel cell. As a result, the cogeneration system satisfies both heating and cooling capability, performing 175 and 145 kW, respectively.

• 한국가스학회지
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• 제19권6호
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• pp.28-33
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• 2015

2012년 7월부터 우리나라 천연가스 열량에 대한 기준이 기존의 표준열량제에서 열량범위제로 변경되면서 가정이나 산업체로 공급되는 가스 열량 변화가 가스기기 성능에 미치는 영향을 규명하고자 하는 노력이 이루어지고 있다. 특히 천연가스를 주 연료로 사용하는 열병합 발전용 엔진의 경우 이러한 열량 변화에 의해 엔진 성능 전반에 걸쳐 영향이 있을 것으로 예상된다. 따라서 이번 연구에서는 열량범위제를 고려한 CNG 열량 변화가 디젤-CNG 혼소엔진의 효율 및 연소특성에 미치는 영향에 대해 조사하였다. CNG 모사 연료의 발열량은 $10,400kcal/Nm^3$에서 $9,400kcal/Nm^3$까지 질소 가스를 CNG에 희석하는 방식으로 변경을 하였다. 우선 디젤연료의 분사시기와 혼소율을 80%로 고정한 조건에서 가스연료의 발열량 변화가 엔진 효율 및 출력 변화에 미치는 영향을 살펴보았으며, 열방출율 및 연소압력 등의 변화를 측정하였다. 실험 결과로부터 가스 열량이 낮아질수록 엔진 출력과 효율이 모두 감소함을 알 수 있었으며, 점화지연시간과 연소기간은 가스 열량 감소에 관계없이 일정하게 유지되는 반면 최대연소압력은 낮아짐을 볼 수 있었다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.199-204
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• 2009

This study analyzed the central heating system and the cogeneration system among the methods of supplying energy which have application to the Hydrogen Fuel Cell system and apartment complexes for performance evaluations. Therefore, a feasibility study on the first application of this system in an apartment complexes was considered to evaluate the energy performance by the amount of fuel consumed by the system using Hydrogen Fuel Cell energy and environmental performance by the amount of greenhouse gas emissions. As a result, the Hydrogen Fuel Cell system consumes 83% of fuel while the cogeneration system consumes 81% of fuel comparison to conventional central heating system. The Hydrogen Fuel Cell and the cogeneration system produce 73%t and 70% of greenhouse gas emissions in comparison to conventional central heating system.

• 한국산업융합학회 논문집
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• 제22권2호
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• pp.163-171
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• 2019

Recently, rural housing in urban areas has been increasing due to the improvement of income level. With the increase of the construction of the power house, the installation of the heating system using the harmonious fuel for the purpose of heating and the beauty of the room is increasing rapidly. In addition to the increasing use of firewood heating equipment, the incidence of fire is also increasing. Analysis of the National Fire Data System of the Fire Department The result of the analysis of the National Fire Data System Many parts of the fire are incinerated by the accumulation of tar due to the incompleteness of periodic cleaning inside the cylinder. The distance between the fire extinguisher and the combustible materials such as ceiling, Resulting in fire. In addition, it was found that much of the fire of the firewood heating system in the time zone occurs during the sleeping and resting time and there is not enough time for the residents to cope. This, in turn, causes serious harm to the lives and property of the users of the pyrotechnic heating system. Therefore, in this study, domestic and foreign standards and laws related to fuel oil heating facilities were analyzed and 12 cases of fire accidents were analyzed. Through the revision of the fire prevention and firefighting facilities installation and maintenance law, the installation standards of the alarm and fire extinguishing facilities were presented.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.83-85
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• 2013

With an increase in the use of low rank coals in power plants, various operational issues were raised in the fuel storage and supply, combustion, boiler and flue gas treatment systems. In the fuel storage and supply system, the main issue is the self-heating propensity of low rank coals leading to spontaneous combustion in yard storage, transport and pulverization. This study evaluated the reactivity of various sub-bituminous and bituminous coals with oxygen at low temperatures by analyzing the temperature increase characteristics of coals under a constant flow rate of oxygen supply. The results were quantified to a self-heating index and the relation with the fuel properties were evaluated.

• Journal of Biosystems Engineering
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• 제24권4호
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• pp.351-358
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• 1999

In these days, we are faced to a couple of difficult problems, the one is the unstable price of the energy due to the shortage of fossil fuel resources and the other is the serious environmental pollution from the excessive consumption of fossil fuel. In order to save the thermal energy for the house heating, in this study the heat pump using the natural thermal energy resources was provided for Ondol heating and the thermal energy consumption of the heat was compared to that of oil boiler. The results could be summarized as follows: 1. In the Ondol room the temperature difference between the Ondol surface and room air was about 5∼$10^{\circ}C$ in accordance with the ambient temperature. 2. The Ondol room heating efficiency of the heat pump with compressor of 2PS was the highest at the water flow rate of 200 l/h. 3. The energy saving rate of the heat pump to the oil boiler for heating the Ondol system was 19.3%. 4. The Ondol heating cost of the heat pump was less 20.6% than that of oil boiler when oil price was 478 won/l.

• 한국가스학회지
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• 제20권6호
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• pp.43-49
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• 2016

전 세계적인 천연가스 저열량화 추세에 따라 우리나라 천연가스 열량 기준이 기존의 표준 열량제에서 보다 유연한 열량범위제로 개선되었다. 이 같은 변화는 가정이나 산업체 전반에 걸쳐 가스기기 성능에 직접적인 영향을 미치기 때문에 이를 규명하고자 하는 연구가 필요하다. 특히 열병합 발전용 엔진으로 사용되는 디젤-CNG 혼소엔진의 경우 도시가스를 주 연료로 사용하기 때문에 발열량 변화는 발전 사업자의 수익성 확보와 연관되는 중요한 사안이다. 따라서 본 연구에서는 열량범위제 내에서 허용하는 CNG 발열량 변화가 디젤-CNG 혼소엔진의 배기특성에 주는 영향에 대해 조사하였다. 도시가스 발열량 변화를 모사하기 위해 열량 범위 상한선인 $10,400kcal/Nm^3$의 CNG 연료에 질소를 희석시켜 발열량을 $10,400kcal/Nm^3$에서 $9,400kcal/Nm^3$까지 변경하였다. 혼소율 80% 조건에서 디젤 연료 분사 시기는 16 CAD BTDC, 분사압력은 110 MPa로 고정하고 엔진회전수 및 토크는 1800 rpm/500 Nm으로 설정하여 시험을 수행하였다. 엔진시험 결과 발열량이 감소할수록 불완전연소가 증가하여 THC, $CH_4$ 및 CO 배출량은 증가하는 반면 NOx 배출량은 감소함을 확인하였다. 그리고 이 같은 결과를 바탕으로 배기 특성 변화에 대해 대응할 수 있는 방안에 대해 고찰하였다.

• 플랜트 저널
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• 제10권3호
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• pp.45-51
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• 2014

본 연구에서는 기존 가정용연료전지에서 활용이 미약한 중저온의 배열을 건물난방부하에 적용할 수 있도록 온도 안정화 장치를 개발하였으며 이 장치가 기존 난방설비와 연계가 가능하도록 제어시스템을 구축하였다. 연료전지 시스템의 정상작동을 위해서는 연료전지로부터 배출되는 온수의 공급온도가 $60^{\circ}C$이어야 하고 다시 연료전지로 회수되는 작동 유체의 환수온도는 항상 $55^{\circ}C$로 유지하여야 한다. 본고에서는 먼저 스택배열 활용을 극대화하기 위해 CFD 분석을 통해 소형열교환기와 기존 난방설비배관과의 최적 연계장치시스템을 구성하였다. 또한 계절별 난방 수온의 불규칙한 온도변화에 대응하기 위해서 연료전지 스택의 열원과 아파트세대 난방용 환수관을 연결한 온도자동조절 밸브를 사용하여 온도안정화 장치를 개발하였다. 소형열교환기와 통합 활용할 수 있도록 설정된 온수의 온도가 편차 ${\pm}0.5^{\circ}C$ 이내에서 유지되도록 하였다. 이 연구결과를 통해 연료전지인 PEMFC의 배열을 건물난방부하에 활용이 추후 가능할 것으로 예상된다.

• 신재생에너지
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• 제5권3호
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• pp.40-48
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• 2009

Recovered heat has been considered as a renewable energy in Europe since 2008 because its great effect on energy saving and carbon decreasing in plant process. Energy saving and decreasing green gas are critical issue today, so various technologies to save energy and decrease carbon dioxide in plant process have been applied to many industrial area. In this paper, the feasibility of condenser heat recovery by heat pump in power plant for district heating and fuel line preheating were reviewed by verifying energy (heat) balance and mass balance of power plant model. Some ways to compose proper system to recover heat of condenser are suggested and their possibilities are also reviewed. Limitations on heat recovery in power plant are also reviewed. The results are verified by calculating input/output energy based on actual performance test data of Taean Thermal Power Plant in Korea. There is noticeable improvement of plant performance in some cases which demand low temperature (<100 C) heat like distrcit heating, fuel line heating, and so forth.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.105-110
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• 1999

The elementary experiment was performed to develop the emulsified fuel production system using pressure injection nozzle in this study. The stabilities and characteristics of emulsified fuel which is produced through direct spray of water via pressure injection nozzle into oil are examined. To understand performance of emulsion production, stabilities of emulsified fuel which is made by adding water to the mixed fuel of Bunker-C and 10 $^{\sim}$ 50 vol% of heating oil were investigated. According to volume ratios of surfactant in heating oil the stability and SMDs were measured