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고압 천연 가스 인젝터의 분무 특성에 관한 연구

An Investigation on the Spray Characteristics of a Compressed Natural Gas Injector

  • THONGCHAI, SAKDA (Graduate School of Department of Mechanical Engineering, University of Ulsan) ;
  • KANG, YUJIN (Graduate School of Department of Mechanical Engineering, University of Ulsan) ;
  • LIM, OCKTAECK (School of Mechanical Engineering, University of Ulsan)
  • 투고 : 2018.04.06
  • 심사 : 2018.04.30
  • 발행 : 2018.04.30

초록

This study was carried out to investigate the injection characteristics of 800 kPa compressed natural gas compressed natural gas (CNG) injector developed in Korea. The CNG injector with multi-holes, employed in this experiment, was designed to inject CNG in the manifold at high pressure of 800 kPa. The spray macroscopic visualization test was carried out via Schlieren photography to study fuel-air mixing process. The fundamental spray characteristics, such as spray penetration, spray cone angle and spray velocity, were evaluated in the constant volume combustion chamber (CVCC) with varying the constant back pressure in CVCC from 0 to 1.8 bar. For the safety reason, nitrogen ($N_2$) and an acetone tracer were utilized as a surrogate gas fuel instead of CNG. The surrogate gas fuel pressures were controlled at 3, 5.5, and 8 bar, respectively. Injection durations were set at 5 ms throughout the experiment. The simulating events of the low engine speed were arranged at 1,000 rpm. The spray images were recorded by using a high-speed camera with a frame rate of 10,000 f/s at $512{\times}256pixels$. The spray characteristics were analyzed by using the image processing (Matlab). The results showed the significant difference that higher injection pressure had more effect on the spray shape than the lower injection pressure. When the injection pressure was increased, the longer spray penetration occurred. Moreover, the linear relation between speed and time are dependent on the injection pressure as well.

키워드

참고문헌

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