An Investigation of Performance Characteristics of A Biogas-Fueled Motorcycle Engine

현탄 콩,치엠트란 람,부티김 차우 한국수소및신에너지학회 2012 한국수소 및 신에너지학회논문집 Vol.23 No.4

To determine the performance characteristics of motorcycle engine using biogas for practical use, the intake system of a 110 cc motorcycle engine is properly modified to operate with biogas as a fuel. Biogas is a potentially renewable fuel for replacing gasoline in future, but it has high percentage of CO2 that could lead to slow the burning rate of biogas-air mixture and cause instability in combustion. Thus, the performance characteristics of biogas-fueled motorcycle engines could be different from those of gasoline motorcycle engines. In this paper, the important parameters of performance characteristics (such as: power output, thermal efficiency, fuel consumption, exhaust emission,…) of biogas-fueled motorcycle engine are studied and estimated with change of engine speed and load. The obtained results when operating with biogas are used to compare with that of gasoline fuel under the same operating conditions. Engine speed in the experimental is changed from 1500 rpm (idle-mode) up to 3500 rpm by a step of 500 rpm. Engine load is changed from zero to maximum load with the help of an exciting voltage device from generator-type dynamometer. The experimental results show that the tested engine operated with richer biogas-air mixture than that of gasoline-air mixture under the same test conditions. Biogas-fueled engine gives a higher fuel consumption and lower thermal efficiency under the same power output. Brake thermal efficiency of biogas engine is found to be about 3% lower than gasoline-fueled motorcycle engine for whole range of speed. Exhaust emission of biogas-fueled motorcycle engine (such as: CO, HC) is found to be lower than the limitation level of the emission standards of Vietnam for motorcycle engines (CO <4.5% HC <1200 ppm).

크랭크 없는 고효율 스팀엔진 개발

이대희(D.H. Lee),차윤석(Y.S. Cha),이대근(D.K. Lee),이준식(J.S. Lee),임창율(C.Y. Lim),김영생(Y.S. Kim),배종렬(J.R. Bae) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

An innovative crankless steam engine utilizing the rack and pinion has been developed to improve the thermal efficiency of the engine. This newly developed crankless steam engine converted the thermal energy of steam to the electrical power output by way of the rack and pinion instead of the conventional crank. Straight motion due to the rack changed to the rotary motion by the pinion gear of the clutch. The crankless steam engine performance was tested with steam at 5 to 6.5 ㎏<SUB>f</SUB>/㎠ and the power output varied from 2.4 to 8.0 ㎾. It follows that the maximum efficiency of the crankless steam engine has reached 74 % when the steam inlet pressure is 6.5 ㎏<SUB>f</SUB>/㎠ and the power output is 8.0 ㎾. The maximum efficiency of this engine is more than 2 times as high as the existing conventional crank engine.

선박용 저속 디젤엔진의 출력산정에 관한 연구

정균식(Kyun-Sik Jung),이진욱(Jin-Uk Lee),정진아(Jin-Ah Jung),최재성(Jae-Sung Choi) 한국마린엔지니어링학회 2010 한국마린엔지니어링학회 학술대회 논문집 Vol.2010 No.4

Recently, EMS(Engine Monitoring System) is reported that the IHP calculated and measured from electronic indicator has a deviation compared to mechanical indicator. The same results has been shown in case of trainingship HANNARA, so it is required to analysis about the estimation of engine output. In this paper it is studied on the cause of error for engine performance analysis and investigated the reliability of engine output by the acquisition methods of cylinder pressure data.

개방형 액체로켓엔진의 추력제어를 위한 최적출력 추종제어 시뮬레이션

차지형(Jihyoung Cha),조우성(Woosung Cho),고상호(Sangho Ko) 한국추진공학회 2020 한국추진공학회지 Vol.24 No.2

This paper deals with an optimal output tracking control for open-cycle liquid propellant rocket engine. For this purpose, we modeled simplified mathematical model of open-cycle liquid propellant rocket engine and designed optimal output feedback control system using combustion chamber pressure. For design the closed-loop system of open-cycle liquid propellant rocket engine, we designed optimal output feedback linear quadratic tracking control system using the linearized model and demonstrated the performance of the controller through numerical simulation.

개방형 액체로켓엔진의 추력제어를 위한 최적출력 추종제어 시뮬레이션

차지형(Jihyoung Cha),조우성(Woosung Cho),고상호(Sangho Ko) 한국추진공학회 2019 한국추진공학회 학술대회논문집 Vol.2019 No.11

본 논문에서는 개방형 액체로켓엔진의 제어 알고리즘을 다룬다. 이를 위해 엔진의 각 구성품들을 기준으로 수학적 모델링을 하였으며 추력제어를 위하여 연소실 압력을 피드백하여 제어시스템을 구축하였다. 제어시스템을 위하여 최대추력 상태에서 선형 모델을 이용하여 최적 출력피드백 LQ 추종제어기를 설계하였으며 시뮬레이션을 통해 제어기의 성능을 검증하였다. This paper deals with an optimal output tracking control for open-cycle liquid propellant rocket engine. For this purpose, we modeled simplified mathematical model of open-cycle liquid propellant rocket engine and designed optimal output feedback control system using combustion chamber pressure. For desing the closed-loop system of open-cycle liquid propellant rocket engine, we designed optimal output feedback linear quadratic tracking control system using the linearized model and demonstrated the performance of the controller through numerical simulation.

차량 흡기시스템의 냉각공기 유로 개선에 의한 통합 시동발전기용 단기통 디젤엔진 및 보조전원공급장치의 출력성능 향상

이태의(Tae Eui Lee),Andreas Stabel,이가영(Ga Young Lee) 대한기계학회 2022 大韓機械學會論文集B Vol.46 No.6

최근 차량 전기 · 전자 장비의 첨단화로 인해서 추가적인 전원공급을 위해 고출력의 초소형 엔진을 이용한 보조전원공급장치(APU)의 수요가 증가하고 있다. 이에 본 연구에서는 매우 제한된 공간에서 최소의 설계 개선으로 기존에 사용하지 않는 플라이휠의 냉각 공기를 단기통 수랭식 엔진 흡기시스템으로 재순환시키고, 발전기 고정자 철심의 적층 면적을 증가하는 방법으로 엔진 및 전기적 발전출력을 향상시키기 위한 실험적 연구이다. 엔진 상태에서는 성능 변수(토크, 출력 등) 등을 분석하였고, 완성품 발전시스템에서는 부하에 따른 전압 · 전류 등의 출력특성 변화를 실험하였다. 본 실험 결과에 따르면 수랭식 디젤 엔진 3,000 rpm 조건에서는 평균 8.7%의 출력증가를 나타내었고, 통합 시동형 APU 시스템 상태의 전기적 발전출력 성능은 최소 12.7%가 증가한 10.16 kW(363 A)로 나타났다. Due to the recent technological advancement of vehicles and electronic equipment, the demand for additional power supply by auxiliary power units (APU), using small diesel engines (less than 14 kW), is increasing. Therefore, this experimental study was conducted to investigate the improvement of the engine and electrical power output by recirculating the cooling air of the flywheel using an improved air intake system design consisting of a water-cooled single cylinder engine; and by increasing the area of the limited space in the generator stator iron. The engine performance parameters were analyzed and changes in the output characteristics of the generation system, such as voltage and current, were tested. From the results, the diesel engine exhibited an average power increase of 8.7% at 3,000 rpm while in the electrical power state, and the generation output was 10.16 kW, which corresponds to a 12.7% (363 A) increase in output.

이공계 유학생을 위한 과학기술문 쓰기 교육 방안

정호진,이소현 한국언어문화교육학회 2010 언어와 문화 Vol.6 No.2

This paper aims to present a teaching proposal of scientific and technical writing for future students majoring in science and engineering in universities. Academic purpose Korean has been newly centered in the field of Korean language education, since students from abroad have sharply increased within the past ten years. Many researches have been done and many textbooks have been developed for academic purpose Korean language learners. However, only a few researches were conducted and no Korean language textbooks have been published for Korean language learners majoring in science and engineering. In the field of academic purpose Korean language education, “writing” is mostly needed, but learners find it most difficult. Therefore, in this paper, a teaching plan is proposed for how to write scientific and technical paper, focusing on experiment report. As for this, output-oriented writing approach and content-based instruction are adopted. This is because scientific and technical writings have special frames and forms to be taught, and it is necessary to narrow the gap between the learning content given in Korean language courses and in lessons of ones’s major field of study for future science and engineering students.

Output Voltage Control of Hydrogen Engine Generator using A Hill Climbing Method by Adjusting the Hydrogen Flow Rate with A Proportional Control Valve

Hikari Nitta,Nobukazu Hoshi,Koki Ishizuka,Kazuhito Fukuda 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Hydrogen engine generator has attracted attention because it is cheaper than fuel cells and does not emit CO₂. However, hydrogen flow rate must be controlled appropriately according to output power, which changes depending on the load. If the hydrogen flow rate input into the engine was not controlled appropriately, the output voltage is dropped or the fuel efficiency becomes worse. In this paper, output voltage control of a hydrogen engine generator using a hill climbing method with an evaluation function simulating a quadratic function is proposed. It is clarified by experiments that the output voltage of the generator can be controlled to a constant value by applying the hill climbing method with the evaluation function even when the load fluctuates. In addition, it is shown that the response time can be shortened by 0.4 sec with the same system configuration as the previously proposed PI controlled system.

A Study on Characteristics of Power Generation System Using Biogas from the Waste of Pig Farm

Thanh-Cong Huynh,Xuan-Mai Pham,Dinh-Hung Nguyen,Minh-Tien Tran 한국수소및신에너지학회 2010 한국수소 및 신에너지학회논문집 Vol.21 No.5

electric production, a SI gasoline engine is modified to use biogas fuel and was installed in a 20 KVA power generation system. An electronic speed regulation unit is developed to keep the system speed at 1500rpm. Experimental investigations have been carried out to examine the performance characteristics of power generation system (such as: system frequency, phase output voltage,...). In addition, the operating parameters and output emissions (NOx, HC, and CO2) of biogas-fueled engine are preliminary evaluated and analyzed for the change of system load. Results indicated that the researched power generation system shows a high stability of output voltage and frequency with help of speed regulator. Biogas fuel (mainly CH4 and CO2) has an environmental impact and potential as a green alternative fuel for SI engine and they would not require significant modification of existing engine hardware. Output emissions of biogas-fueled engine are found to be relative low. NOx emission increases with the increase of output electric power of the power generation system.

Modeling and Simulation of PV Engineering Mathematical Model Parameters Calculation Based on Newton-Raphson Method

Peng Zhang 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.8

Traditional Photovoltaic (PV) mathematical models have advantage of high accuracy, but its characteristics are multi-parameters and non-linear, which makes it difficult to be solved. Obviously, these are not suitable for engineering design since it requires both complexity and accuracy. In this paper, a simplified precision engineering PV mathematical model is proposed based on analysis of double diode PV cells mathematical model, and also gives a parameter calculation method based on Newton-Raphson method. Four different kinds of PV materials and variable resistance parameter characteristics are separately tested under different irradiance and temperature conditions. The results show that the proposed model can quickly and accurately reflect the PV model I-V and P-V characteristics, which has good versatility and sensitivity, and provides strong support for PV system related research.