한국가스학회지 (Journal of the Korean Institute of Gas)

  • 제17권1호
  • /
  • Pages.7-12
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  • 2013
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  • 1226-8402(pISSN)
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  • 2713-6922(eISSN)
한국가스학회 (The Korean Institute of GAS)
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HCNG 엔진의 공기과잉율 변화에 따른 노킹 특성에 관한 연구

A Study on the Knocking Characteristics with Various Excess Air Ratio in a HCNG Engine

  • Lim, Gihun (Dept. of Environment & Energy Mechanical Engineering, University of Science and Technology) ;
  • Park, Cheolwoong (Korea Institute of Machinery and Materials) ;
  • Lee, Sungwon (Korea Institute of Machinery and Materials) ;
  • Choi, Young (Korea Institute of Machinery and Materials) ;
  • Kim, Changgi (Korea Institute of Machinery and Materials) ;
  • Lee, Janghee (Korea Institute of Machinery and Materials)
  • 투고 : 2012.06.15
  • 심사 : 2013.01.02
  • 발행 : 2013.02.28
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초록

자동차 배기가스 규제가 강화됨에 따라 천연가스에 수소를 첨가하는 수소-천연가스 혼합연료(HCNG)를 기존의 압축천연가스(CNG) 엔진에 적용하려는 많은 연구들이 진행되고 있다. 그러나 수소의 높은 연소 속도로 인한 역화, 조기착화, 노킹(knocking) 등의 이상연소 발생 가능성은 엔진의 가열 또는 열효율 및 출력의 저하를 야기하는 문제점이 발생할 수 있다. 본 연구에서는 CNG 연료에 수소를 일정 부분 혼합한 HCNG 연료를 기존의 CNG 엔진에 적용하여 희박연소 한계 확장을 통해 연소 성능 개선을 확인하고, CNG와 HCNG 연료의 노킹 특성을 파악하고자 하였다. 공기과잉율의 변화에 따른 노킹 발생 조건을 관찰함으로써 HCNG 연료의 적용성 및 노킹마진을 평가하고자 하였다. HCNG 연료 사용 시 최적운전조건에서 노킹 문제없이 엔진을 운전할 수 있었으나 노킹이 일어날 수 있는 가능성이 높아져 이에 대한 대비가 필요할 것으로 판단된다.

As emission regulation for vehicle has been reinforced, many researches carried out for HCNG(hydrogen-natural gas blends) fuel to the conventional compressed natural gas (CNG) engine. However, abnormal combustion such as backfire, pre-ignition or knocking can be caused due to high combustion speed of hydrogen and it can result in over heating of engine or reduction of thermal efficiency and power output. In the present study, improvement of combustion performance was observed with HCNG fuel since it can extend a flammability limit. Knocking characteristics for CNG and HCNG fuel were investigated. Feasibility of HCNG fuel was evaluated by checking the knock margin according to excess air ratio. The operation of engine with HCNG was stable at minimum advance for best torque(MBT) spark timing and knock phenomena were not detected. However, it is necessary to prepare higher knock tendency since possibility of knock is higher with HCNG fuel.

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참고문헌

  1. Fanhua, M., Haiquan, L., Yu, W., Yong, L., Junjun, W., and Shuli, Z., "Combustion and emission characteristics of a port-injection HCNG engine under various ignition timings", Int. Journal of Hydrogen Energy, Vol. 33, pp. 816-822, (2008) https://doi.org/10.1016/j.ijhydene.2007.09.047
  2. Fanhua, M., Mingyue W., Long, J., Renzhe, Chen., Jiao, Deng., and Nashay, N., "Performance and emission characteristics of a turbocharged CNG engine fueled by hydrogen-enriched compressed natural gas with high hydrogen ratio", Int. Journal of Hydrogen Energy, Vol. 35, pp. 6438-6447, (2010) https://doi.org/10.1016/j.ijhydene.2010.03.111
  3. Nafiz, K., Bilge, C., S., O. A., and Kadir, A., "Investigation of combustion characteristics and emissions in a spark-ignition engine fuelled with natural gas-hydrogen blends", Int. Journal of Hydrogen Energy, Vol. 34, pp.1026- 1034, (2009) https://doi.org/10.1016/j.ijhydene.2008.10.075
  4. Heywood, J. B., Internal Combustion Engine Fundamentals, 2nd ed., McGRAW-HILL, The United States, (1988)
  5. Konig, G. and Sheppard, C., "End Gas Autoignition and Knock in a Spark Ignition Engine", SAE Technical Paper 902135, (1990)
  6. Nates, R. and Yates, A., "Knock Damage Mechanisms in Spark-Ignition Engines", SAE Technical Paper 942064, (1994)
  7. König, G., Maly, R., Bradley, D., Lau, A. et al., "Role of Exothermic Centres on Knock Initiation and Knock Damage", SAE Technical Paper 902136, (1990)
  8. Fitton, J. and Nates, R., "Knock Erosion in Spark- Ignition Engines," SAE Technical Paper 962102, (1996)
  9. Valtadoros, T. H., Wong, V.W., and Heywood, J. B., "Engine Knock Characteristics at the Audible Level", SAE Technical Paper 910567, (1991)