• 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.

• 한국도로학회논문집
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• 제13권3호
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• pp.185-193
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• 2011

가변축은 대형화물자동차에 주로 장착되는 보조차축으로써, 물류비용 절감과 도로포장면 파손방지, 유류비 등의 차량운행비용 절감을 목적으로 도입되었다. 그러나 유류비절감 측면에 대한 가변축의 사용효과가 실증적 실험을 통해 입증되지 않았을 뿐만 아니라, 일부 운전자들의 막연한 기대심리로 인한 잘못된 가변축 활용사례가 발생되고 있다. 본 연구에서는 가변축 사용 여부에 따른 연료소모량 변화를 확인하고자 실제 도로주행 실험을 수행하였으며, 실험결과를 바탕으로 연료소모원단위 모형을 개발 및 적용하여 가변축 사용여부별 연료소모량을 비교하였다. 그 결과, 가변축을 사용하지 않을 시에 연료소모량 감소가 예상되었으며, 수치상으로 공차주행 시 -0.83%, 만차주행 시 -2.15%를 나타내었다. 공차주행 시 절감율은 제도의 효과를 정량적으로 나타내는 수치로써, 금액으로 환산 시 약 300억 원에 달한다.

• 한국자동차공학회논문집
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• 제22권5호
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• pp.35-43
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• 2014

The automobile industry requires technological innovations to reduce fuel consumption with the public interest in environmental conservation in recent years. Thus, the hybrid system is applied not only to passenger cars but also commercial vehicles. The purpose of this paper is to develop engine ECU_ILS to develop commercial hybrid vehicles. In order to develop the engine and vehicle, the dynamometer and exhaust gas analyzer is needed. However, a lot of time and cost are required. In contrast, the model-based development environment that can be applied to a variety of test conditions can reduce development time. Therefore, a HILS system environment that can consider the behavior of actual vehicles for evaluation of the control logic, fuel consumption and exhaust gas is required. This engine ECU_ILS system was developed in this study, can analyze parameter such as the fuel injection rate, fuel injection time, fuel consumption and exhaust gas like the actual vehicle test using map data. Also, this system is expected to be able to analyze the characteristic of vehicle behavior and the development of peripheral device in relation to engine and vehicles. This HILS system can be used to develop control strategies of commercial hybrid vehicle systems in the future.

• 융합신호처리학회논문지
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• 제22권1호
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• pp.7-13
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• 2021

최근 해운산업에서는 환경규제에 대한 중요성이 높아지고 있으며, 이를 위한 산업의 요구가 급격히 높아지고 있다. 이에 샤프트제너레이터는 선박에 가장 빠르게 적용이 가능한 환경규제 대응기술로 선주의 요구가 증가하고 있다. 샤프트제너레이터는 메인추진엔진에 전동기를 설치하여, 부하환경에 따라 가변적으로 사용함으로 메인추진엔진의 연료소모율을 줄일 수 있는 장치이다. 저속에서는 모터의 힘으로 동작하고, 급격한 부하가 필요할 때에는 메인추진엔진과 모터가 함께 동작함으로 효율적인 운전이 가능하다. 본 논문에서는 MATLAB Simulink를 이용하여 터그보트의 디젤엔진과 샤프트제너레이터를 모델링하고, 시뮬레이션을 통해서 연료소모율을 검증하였다.

• 동력기계공학회지
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• 제21권6호
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• pp.110-116
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• 2017

Recently the global warming caused by greenhouse gas has emerged as a global environmental problem. For this reason the continued efforts to reduce greenhouse gas emission by international cooperation and each country are in progress. Climate changing has been recognized as the world economy development from fossil fuel use is the culprit. The international maritime organization marine environment protection committee of the global warming reduction emerged restrictions on air pollution have been strengthened. Therefore, the author has investigated the effects of fuel temperature on the characteristics of combustion and performance, using an four-cycle, six cylinders and direct injection diesel engine. The results of cylinder pressure, rate of pressure rise, rate of heat release and specific fuel consumption were increased by changing of fuel temperature.

• Journal of Advanced Marine Engineering and Technology
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• 제21권4호
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• pp.356-363
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• 1997

Many research works have been carried out to investigate the factors governing the performance of diesel engine. The area of the study has been focused on reducing both of NOx and smoke because of many difficulties to reduce them simultaneously in diesel engines. One of the efforts is an application of EGR technology to reduce NOx emission, which is very effective, but increases other emissions and makes fuel economy worse. In order to solve the problem, EGR is employed with water emulsified fuel and tested in this paper. Emulsified fuel is produced by centrifugal mixer and the amount of water is controlled by water injector and pulse generator, and EGR rate is controlled with 6-step control valve. The chamber pressure, fuel consumption and emissions are measured with various values of both EGR and water mixing rate, The results show that NOx emission is reduced much rather and smoke is also reduced simultaneously.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 추계학술대회논문집
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• pp.93-96
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• 2009

In the cathode channel of a PEM fuel cell, the local concentration of oxygen near the gas diffusion layer (GDL) decreases in streamwise direction due to chemical reactions, which degrades the efficiency of the oxygen consumption and overall fuel cell efficiency. We numerically studied the influence of the swirling flow generated by a slanted groove mixer (SGM) on the concentration distribution of oxygen. We found that the swirling flow can increase the concentration of oxygen near the GDL, and subsequently improves the oxygen consumption rate.

• 수산해양기술연구
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• 제28권2호
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• pp.191-196
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• 1992

This paper is an experimental study to investigate utility of ultrasonic treatment of fuel oil in diesel engine. Experiment was carrid out to clarify the effect of ultrsonic vibration on the characteristics of maximum pressure, fuel consumption ratio, smoke, BMEP and torque. The result obtained are as follows: 1. In the case of given ultrsonic vibration, the maximum pressure is increased in all experimental conditions. 2. In the case of given ultrsonic vibration, the decrease effect of fuel consumption rate is increased at low rpm. 3. The generation quantity of soots is increased according to load. In the case of given ultrsonic vibration, the decreased quantity of soots does not very according to load. 4. In the case of given ultrsonic vibration, the BMEP and torque are increased at low load.

• Journal of Advanced Marine Engineering and Technology
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• 제8권2호
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• pp.25-38
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• 1984

Since the energy shock in 1973, there have been wide studies for the developments of the alternative energy source, the rationalization of the energy utilization and the energy economy because of the recognition of the limitation of energy source all over the world. This study is experimentally examined in and compared with the engine performance of output, torque and fuel consumption rate, and the exhaust emissions with the change of engine rmp in the cases of using water-gashol blends, gashol and gasoline as a fuel in a conventional 4 cycle 4 cylinder gasoline engine. In the case of using water-gashol blends, it is installed by the exhaust manifold pipe into the intake manifold, and water is injected from nozzle fitted up the air horn of the carburetor. The results are obtained as follows; 1. In the case of an addition with water, the engine output and the torque are little difference with the case of gasoline. 2. The fuel consumption rate is decreased as compared with the case of gasoline. Especially, the decrease in quantity is remarkable at the low rpm. 3. The exhaust emissions are remarkably decreased as compared with the case of gasoline. Especially, decreases of CO and HC in quantity are remarkable at the low rpm, and a decrease of No/sub x/ in quantity is remarkable at the high rpm. 4. There is a moderate condition of operation because the producing factors of NO/sub x/ and CO, HC are contrary to each other.

• 청정기술
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• 제21권2호
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• pp.96-101
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• 2015

수소를 환원제로 사용한 산화철의 유동 환원에서, 환원율에 대한 다양한 공정 변수를 통해 산화철의 하나인 적철광의 환원 거동을 면밀히 관찰하였다. 본 연구를 위해 특별히 설계된 실험실 규모의 유동층 장치에서 목적으로 하는 환원 특성에 대한 가스 속도, 환원 시간 및 온도의 최적 값을 평가 하였다. 최적의 환원율을 나타낸 온도는 750 ℃, 환원 시간은 30분이며 이들을 다음의 시험을 위한 시작점으로 매개 변수 값을 설정 하였다. 가장 높은 관심을 갖는 변수들 중 하나는 가스의 소비 원단 위로, 이는 최적의 조건에서 산화철 1톤을 기준하여 90% 이상의 환원율을 달성하기 위해 요구되는 가스의 양을 말한다. 이 매개 변수는 실험실 수준 장치의 스케일 엎에 있어서 중요한 인자이며, 본 연구를 통해 1,500 Nm³/ton-ore가 산화철이 가장 높은 환원율을 갖기 위한 최적의 가스 소비 원단위 임을 확인하였다.