• Title/Summary/Keyword: 수소기관

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The Realization of High Performance in a Hydrogen-Fueled Engine with External Mixture by Retarding Valve Timing and Super Charging (밸브 타이밍 지각과 과급에 의한 흡기관 분사식 수소기관의 고성능 실현)

  • Lee, Kwang-Ju;Hur, Sang-Hoon;Lee, Jong-Tae
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.6
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    • pp.464-470
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    • 2009
  • In order to analysis the possibility of high expansion and performance without backfire in a hydrogenfueled engine using external mixture injection, combustion characteristics and performance enhancement were analyzed in terms of retarding valve timing and increasing the boosting pressure. As the results, it was found that thermal efficiency increased by retarding intake valve timing with the same level of supplied energy is over 6.6% by the effect of high expansion including effect of combustion enhancement due to supercharging. It was also shown that the achievement of high power (equal to that of a gasoline engine), low brake specific fuel consumption and low emission (NOx of less than 16 ppm) without backfire in a hydrogen-fueled engine is possible around a boosting pressure of 1.5 bar, intake valve opening time of TDC and $\Phi$=0.35 in fuel-air equivalence ratio.

A Study on the Combustion Stabilization and Performance Improvement in the Free-piston Hydrogen Fueled Engine (프리피스톤 수소기관의 연소안정화 및 성능향상에 관한 연구)

  • Noh, K.C.;Yoon, J.S.;Kim, K.M.;Park, S.W.;Lee, J.T.
    • Transactions of the Korean hydrogen and new energy society
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    • v.17 no.2
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    • pp.227-233
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    • 2006
  • A free-piston hydrogen fueled engine is considered as one of the next power systems which is able to obtain high efficiency and low emission, simultaneously. In this study, in order to ensure the possibility as the next generation power system, the combustion characteristics and the performance of the free-piston hydrogen fueled engine are analyzed by using the linear RICEM for the change of injection pressure and equivalence ratio. As the results, in-cylinder maximum pressure is shown at injection pressure $P_{inj}$=6bar. Backfire phenomenon is not observed under experimental condition and knock occurs over ${\Phi}=0.8$. The thermal efficiency is the highest at injection pressure, $P_{inj}$=6bar and equivalence ratio, ${\Phi}=0.7$, respectively.

The development of hydrogen storing system for fuelcell vehicle (연료전지차량용 수소저장시스템 개발 동향)

  • 이성근;임태원
    • 한국전기화학회:학술대회논문집
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    • 2004.06a
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    • pp.141-148
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    • 2004
  • 지구의 환경보존과 에너지원의 효율적인 이용을 위하여 고효율의 환경친화적 청정에너지 기술개발을 활발이 진행중에 있으며, 이중 수소를 이용한 연료전지차 개발이 최근 가장 각광을 받고 있다. 연료전지차 실용화를 위해서는 여러 가지 기술적으로 해결해야 과제가 많으나, 그 중에서도 연료로 사용하고 있는 수소의 안전적인 저장 문제가 중요하다고 하겠다. 수소를 저장하는 방법은 여러 가지 있으나, 현재 기술로 이용 가능한 것은 압축저장 방식이다. 현재 소개되고 있는 연료전지차 대부분에는 350 bar 압축수소저장용기가 탑재되어 $120\~300km$까지 주행이 가능하다. 이는 소비자 입장에서 수소충전을 자주해야 하는 불편사항이다. 이를 보완하기 위해서 초고압 (700 bar) 수소저장시스템과 저압이면서 수소를 더 많이 저장할 수 있는 신 수소저장물질 개발을 각 연구기관에서 활발이 연구중에 있다. 국내에서도 최근에 연료전지차의 관심이 높아지면서 연료전지차량용 부품 개발을 정부과제로 연구중이거나 예정이다. 수소저장분야도 21세기 프론티어사업을 통하여 산.학.연 합동으로 연구를 활발이 진행중에 있다.

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국내 원자력발전소의 수소점화기 제어성능분석

  • Choi, Young;Park, Jong-Hwa
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2003.05a
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    • pp.526-531
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    • 2003
  • 원자력발전소에서는 심각한 사고로 인한 고온상태에서 원자로내부의 물질이 산화반응하여 대량의 수소가 발생한다. 이 때 수소가 폭발하면, 원자력발전소의 건전성에 중대위험이 발생한다. 실제로 미국원자력발전소인 쓰리마일원전(TMI-2) 사고 이후 지금까지 중대사고시 수소거동에 대하여 여러 연구기관에서 많은 연구가 수행되었으나 아직도 많은 기술적 불확실성이 존재한다.(중략)

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An Investigation on Enhencing Thermal Efficiency of a Hydrogen Fueled 2 Stroke Free-piston Engine with Reverse Uni-flow Scavenging (역단류 소기방식을 갖는 2행정 프리피스톤 수소기관의 열효율 향상에 관한 연구)

  • Byun, Chang-Hee;Baek, Dae-Ha;Lee, Jong-Tae
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.3
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    • pp.299-304
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    • 2011
  • A hydrogen fueled 2 stroke free-piston engine with reverse uni-flow scavenging have a advantageous structure for the backfire occurrence, but it can reduce thermal efficiency by the circuit-flow to go through a exhaust-port. In this research, varied boost pressure, SVOT and exhaust pressure are used in a 2stroke free-piston engine with hydrogen fueled for studying the possibility of increasing thermal efficiency of free-piston hydrogen engine. As a result, to increase thermal efficiency of free-piston are suitable to supply the mixture after port closed the exhaust rater than to use the scanvenging. And it was increased by the exhaust pressure, to achieve it must be used the lean-mixture at SVOT aBDC $34^{\circ}$.

The Characteristics of Performance in the Medium Duty Hydrogen-CNG Fueled Engine with Compression Ratio and Rate of Hydrogen Addition (압축비와 수소첨가율에 따른 중형 수소-천연가스 기관의 제반 성능특성)

  • Kim, Yong-T.;Lee, Jong-T.
    • Transactions of the Korean hydrogen and new energy society
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    • v.16 no.2
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    • pp.191-198
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    • 2005
  • Adding hydrogen gas in natural gas leads to stable combustion in internal combustion engine and its performances rely on compression ratio. To analyze the effects of compression ratio and rate of hydrogen addition on the engine performance, the characteristics of overall engine performance including emission were investigated by using the medium duty natural gas fueled engine. As results, it was found that compression ratio occurred knock was nearby compression ratio, $\varepsilon$=14 for the case that hydrogen was enriched in the natural gas fueled engine. But slight knock was occurred at $\varepsilon$=14.7 in the case of neat natural gas. Also HC and $CO_2$ were reduced around 80% and 20% respectively when the rate of hydrogen addition was increased to 50% and compression ratio from $\varepsilon$=13 to $\varepsilon$=14.7.

A Study on the Application of the Lean Boosting in a Hydrogen-fueled Engine with the SI and the External Mixture (흡기관 분사식 수소 SI기관의 희박과급 적용에 관한 연구)

  • Lee, Kwangju;Lee, Jonggoo;Lee, Jongtai
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.2
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    • pp.136-141
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    • 2013
  • In order to achieve simultaneously the ultra-low NOx, the high power and the high efficiency in a hydrogen-fueled engine with SI and the external mixture, the effects of low temperature combustion, performance and exhaust are compared and analyzed by the application of the lean boosting. As the results, the decrease rate of the high temperature in the hydrogen is less decreased than the other fuels by high constant-volume specific heat. However, when the conditions of 1.7bar and ${\Phi}=0.33$ are reached by the lean boosting, the maximum gas temperature of hydrogen is decreased under the temperature of NOx formation and it is possible to stabilize combustion below 2% of COVimep. Also, at that condition, it is feasible to achieve simultaneously NOx-free and the power of gasoline level. Therefore, it is found that the lean boosting is useful in the hydrogen-fueled engine.

The Characteristics of Backfire for a Free-Piston Hydrogen Fueled Engine with Reverse Uni-flow Scavenging (Reverse uni-flow 소기방식을 갖는 2행정 프리피스톤 수소기관의 역화 현상에 관한 연구)

  • Byun, Chang-Hee;Choi, Kwan-Yeon;Back, Dae-Ha;Lee, Jong-Tae
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.2
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    • pp.98-103
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    • 2010
  • In order to develop two-stroke free-piston hydrogen engine to obtain high thermal efficiency and low emission, backfire occurrence have to be prevented. In this research, backfire characteristics are analyzed as functions of the intake valve opening timing and compression chamber pressure under piston by using RICEM (Rapid Intake Compression Expansion Machine) that has reverse uni-flow scavenging. As the result, reverse uni-flow scavenging is advantage about back fire. but, it exists suitable intake valve opening timing and its timing become known that equivalence ratio 1 retard until the piston rises. Also, To rise chamber pressure of lower piston, this does not cause backfire occurs in equivalent ratio 0.6 observed back fire. Therefore, 2cycle hydrogen fueled free-piston engine is undesirable scavenging compression by compressing the piston.

The Effect of Hydrogen Added into In-let Air on Industrial Diesel Engine Performance (흡기중의 수소첨가가 산업용 디젤기관의 성능에 미치는 영향)

  • Park, Kweon-Ha;Lee, Jin-A;Lee, Wha-Soon
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.8
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    • pp.1050-1056
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    • 2010
  • Diesel engines introduce only air into the cylinder, and the air is high lycompressed. Fuel is directly injected into the combustion chamber in high temperature and pressure. Therefore diesel engines have high thermal efficiency because of the high compression ratio, while having high level of particulate matter and nitrogen oxide emissions because of the direct fuel injection. Many technologies have been developed to reduce particulate matter and nitrogen oxide emissions from diesel engines. One of the technologies is hydrogen fuel introduced into the combustion chamber with diesel fuel. In this thesis tiny amount of hydrogen is supplied into the combustion chamber in order to enhance the combustion performance. The engine, in which hydrogen is introduced, is tested. There are 20 test conditions given as 5 torque values of 100%, 75%, 50%, 25%, 0%, and 4 engine speeds of 700rpm, 1000rpm, 1500rpm and 2000rpm for the two cases with or without hydrogen addition. Maximum torques and Idle torques at each engine speed are measured, then the torque values are divided into 4 levels with 25% increasing step. The result shows that the fuel consumption, smoke, CO are reduced while the NOx emission is slightly increased, and the hydrogen addition has not a great effect on the performance at low loads but a great effect at a maximum load.