• Title/Summary/Keyword: efficiency improvement

Search Result 5,525, Processing Time 0.04 seconds

A Study on the Problem-Solving Method and Thermal Efficiency Properties at the Time of High Expansion Realization in a 4-Cycle Diesel Engine (4사이클 디젤기관에서 고팽창 실현 시 문제점 해결방안과 열효율 특성에 대한 연구)

  • Jang, Tae-Ik
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.33 no.6
    • /
    • pp.835-842
    • /
    • 2009

  • The present thesis carried out a research on a compression pressure's reduction phenomenon and its countermeasure according to the thermal efficiency improvement method by a Miller method in 4-cycle low speed diesel engine. In case of retardation of intake valve closing time in a engine, the theoretical heat efficiency shows a remarkably reducing trend when a compression ratio is not compensated. Accordingly, the thermal efficiency showed an increasing trend in case of compensating the compression ratio. Especially, it could be understood that the theoretical heat efficiency at near ABDC $100^{\circ}$ of intake valve closing time in case of compensation of the compression ratio was improved by around 25.1%, and the mean effective pressure was also increased by around 18.6%. Also, as the retardation of intake valve closing time increases, air quantity becomes insufficient due to a backflow phenomenon of intake air and thus thermal efficiency was decreased in a high load operation domain. The solving method of this problem is possible by supercharge. Therefore, in order to improve thermal efficiency by retardation of ntake valve closing time, the thermal efficiency improvement according to low compression is possible when there are a compensation device of a compression ratio and a supercharge device. This is a problem-solving method of low compression and high expansion cycle.

  • https://doi.org/10.5916/jkosme.2009.33.6.835 인용 PDF KSCI

A study on the efficiency improvement of electro-hydraulic pump system by load sensing (부하센싱에 의한 전기유압펌프시스템의 효율 향상에 관한 연구)

  • 황성호;강종우;박성환;하석홍;이진걸
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1993.10a
    • /
    • pp.1178-1182
    • /
    • 1993

  • Variable-displacement pumps are inherently more efficeint than fixed-displacement pumps under varying loads. Their energy-saving characteristics can be improved by the use of special control. This paper shows the improvement of the system by the use of load-sesing technique.

  • PDF

A Suggestion for Improvement of Droppers (드로퍼의 개선 방안)

  • Yoon Yong-Han;Yim Geum-Kwang;Yang Byoung-Nam
    • Proceedings of the KSR Conference
    • /
    • 2005.05a
    • /
    • pp.862-866
    • /
    • 2005

  • This paper presents a suggestion for improvement of droppers. To prevent circulation currents in trolly wire system, we developed a new type of elastic droppers and validated/verified its function. In this paper, therefore, we introduced a developed elastic dropper and analyzed economical efficiency of it.

A Suggestion for Improvement of Cantilever (가동 브래킷의 개선 방안)

  • Yoon Yong-Han;Yim Geum-Kwang;Yang Byoung-Nam
    • Proceedings of the KSR Conference
    • /
    • 2005.11a
    • /
    • pp.688-693
    • /
    • 2005

  • This paper presents a suggestion for improvement of cantilever. We developed a new type of cantilever and validated/verified its function. In this paper, therefore, we introduced a developed cantilever and analyzed economical efficiency of it.

  • PDF