• 연구논문집
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• 통권29호
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• pp.49-55
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• 1999

Heat release rate used to characterize the fire is an important factor for determining the fire size, the fire growth and the time for suppression and evacuation. The purpose of present work is to review theoretical backgrounds and to introduce equations for estimation of heat release rate with oxygen consumption method in fires. Our work also shows the experimental results of applications for liquid fuels. The oxygen concentration is measured by the analyzer of paramagnetic type. The analyzers of Infra-Red type are used to measure the concentrations of $CO_2$ and CO gas. Time delays of analyzers are ignored.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.41-42
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• 2006

A study on the combustion characteristics by using Emulsion Fuel in Diesel Engine is performed experimentally. In this paper, the experiments are performed at engine speed 1800rpm, emulsion fuel ratio is 0%, 10%, 20%, and main measured items are specific fuel consumption, pressure, ratio of pressure rise, rate of heat release etc. The obtained conclusions are as follows. 1) Specific fuel consumption increase maximum 19.8% at low load, but is not effected at full load. 2) Ratio of pressure rise and rate of heat release are about the same in the case of 10% and 20% of emulsion fuel ratio. 3) Cylinder Pressure increase 11.7%, ratio of pressure rise increase 60.4% in case of emulsion fuel ratio 20% at full load. 4) Rate of heat release increase 76.9% in case of emulsion fuel ratio 20% at full load.

• 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.

• 설비공학논문집
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• 제27권5호
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• pp.247-253
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• 2015

The presented work demonstrates the effects of flow rate on the secondary side of DHS (District Heating System). Increasing flow rate at the secondary side of DHS decreases energy consumption and time to reach the set-point of the heated room while increasing heat flux on the floor in the heating space. When flow rate increases, the overall heat transfer rate of radiant floor also increases. However, the results also show overall heat transfer rateto not increased linearly and thus the existence of an optimal flow rate for the secondary side of DHS. Control of the radiant floor with hot water may be more effectively accomplished with a combined control strategy that includes heat flux and a temperature set-point. This experimental analysis has been performed using a lab-scaled DHS pilot plant located at Jeonju University in Korea.

• KIEAE Journal
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• 제16권2호
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• pp.23-31
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• 2016

Purpose: Recently energy consumption is rapidly increasing due to continuous development of social evolution in various field. In this situation, there is a lot of effort to reduce this energy consumption in many ways, especially in building energy. Preceding studies already started to analyze the housing area such as zero energy house and passive house by researching annual building energy consumption, but to apply the results of housing to office building is insufficient since it has different consumption tendency. Method: In this study, eQuest program was used for simulation and the base model is selected among standard office building in ASHRAE 90.1. Variables are divided into passive and active factors for comparison. Result: In passive factors, glazing system showed the highest energy saving rate by 21.3% with triple low-e glass and enhancing wall u-value showed the lowest energy saving rate by 3.6% with 0.15 m2/K. In active factors, VAV system showed 30.9% energy saving rate when compared to CAV system, and heat exchanger showed 10.2% energy saving rate. For regeneration energy part, photovoltaic panel generated 10.4% of base annual energy usage.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.906-911
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• 1993

There will be about 0.25 to 0.3billion tons of grain product including rice, wheat and corn etc. each year in China. An energy analysis on grain drying system on which electricity , oil , coal or sun power and batch, tower with thick or thin layer of grain, infra red radiation. fluidized flowing types grain drying systems were made and compared for the sake of energy saving is shown in this paper.

• 에너지공학
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• 제14권2호
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• pp.147-152
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• 2005

본 논문에서는 화력발전소 보일러 연료소비량을 측정에 의하지 않고 계산으로 구하는 방법을 세부 항목 별로 유도하고 그 결과를 검증하였다. 보일러 경계를 출입하는 Energy in Energy out의 정량적 관계를 분석하여 Energy in에 해당하는 투입열량과 Energy out에 해당하는 흡수열량 및 손실열량으로부터 에너지 출입의 유기적인 관계식을 수립하여 연료소비량 계산식을 유도, 정립하고 실제 운전중인 석탄 및 중 유연소 발전소에 적응하여 계산식의 정확성을 검증하였다.

• 에너지공학
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• 제11권2호
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• pp.178-185
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• 2002

본 연구의 목적은 조기 연료 기화장치가 승용차의 냉간 주행성능에 미치는 영향을 조사하여 평가하는 것이다. 이를 위해 실험은 냉 시동성과 냉간 주행성능으로 나누어 실시하여 연료소비율과 유해 배출 가스량을 측정하고, 실린더내의 연소압력을 근거로 열 발생율, 적산 열 발생량, 질량연소율을 구하였다. 결과는 다음과 같다. 조기연료 기화장치의 장착은 냉 시동 초기부터 난기 완료까지의 연료소비량을 17.7%향상, 냉 시동 초기의 일산화탄소의 배출량은 23%, 탄화수소 배출량은 45% 저감 되고, 또한 냉간 주행시의 엔진의 연소 최고압력, 도시 평균 유효압력의 변동을 4∼6% 개선시키고, 단위 출력당 연료 소비율이 0.2∼2.3% 절감된다. 이것은 조기연료기화장치에 의한 연소실내 최대 열 발생 지연기간 및 주 연소기간이 짧아지기 때문이다.

• 수산해양기술연구
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• 제49권1호
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• pp.58-66
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• 2013

Most of steam power plant in Korea are heating the feed water system to prevent freezing water flowing in the pipe in winter time. The heating system is operated whenever the ambient temperature around the power plant area below 5 degree Centigrade. But this kind of heat supplying system cause a lot of energy consuming. If we think about the method that the temperature of the each pipe is controled by attaching the temperature measuring sensor like RTD sensor and heat is supplied only when the outer surface temperature of the pipe is under 5 degree Centigrade, then we can save a plenty of energy. In this study, the computer program package for simulation is used to compare the energy consumption load of both systems. Energy saving rate is calculated for the location of Youngweol area using the data of weather station in winter season, especially the January' severe weather data is analyzed for comparison. Various convection heat transfer coefficients for the ambient air and the flowing water inside the pipe was used for the accurate calculation. And also the various initial flowing water temperature was used for the system. Steady state analysis is done previously to approximate the result before the simulation. The result shows that the temperature control system using RTD sensor represents the high energy saving effect which is more than 90% of energy saving rate. Even in the severe January weather condition, the energy saving rate is almost 60%.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.65-73
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• 1984

While most of researches on the performance of high temperature grain dryer have dealt mainly with improving dryer capacity and drying speed during the last twenty years, energy efficiency, in fact, has not been emphasized. Current fuel supplies and energy cost have shifted the emphasis to reducing the energy consumption for grain drying while maintaining dryer capacity and grain quality. Since the energy input for drying is relatively large, the recovery and reuse of at least part of the exhaust energy can significantly reduce the total energy consumption in existing drying systems. Unilization of exhaust heat in grain dryer either through direct recycling or by a thermal coupling in heat exchanger have been subject of a number of investigators. However, very seldom research in Korea has been done in this area. Three drying tests(non-recycling, 0.22 recycle ratio, and 0.76 recycle ratio)were performed to investigate the thermal efficiency and heat loss factors of continuous flow type dryer, and to analyze the effect of recycle ratio (weight of exhaust air recycled/total weight of input air) on the energy requriements for rough rice drying. The test results showed that when the exhaust air was not recycled, the energy lost from furnace was 15.3 percent of input fuel energy, and latent and sensible heat of exhaust air were 61.4 percent and 11.2 percent respectively. The heat which was required in raising grain temperature and stored in dryer was relatively small. As the recycle ratio of exhaust air was increased, the drying rate was suddenly decreased, and thermal efficiency of the kerosene burner was also decreased. Drying test with 0.76 recycle ratio resulted in 12.4% increase in fuel consumption, and 38.4% increase in electric power consumption as compared to the non-recycled drying test. Drying test of 0.22 recycle ratio resulted in 6.8% saving in total energy consumption, 8.0% reduction in fuel consumption, and 2.5% increase in electric power consumption as compared to the non-recycled drying test.