Combustion cyclical variation of electronically controlled common rail diesel fueled with methanol-diesel dual-fuel(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年02期
- Page:
- 107-114
- Research Field:
- 汽车与机械工程
- Publishing date:
Info
- Title:
- Combustion cyclical variation of electronically controlled common rail diesel fueled with methanol-diesel dual-fuel
- Author(s):
- LI Gang; ZHANG Chun-hua; LI Yang-yang
- School of Automobile, Chang’an University, Xi’an 710064, Shaanxi, China
- Keywords:
- automobile engineering; internal combustion engine; electronically controlled common rail; methanol-diesel dual-fuel; cyclical variation
- PACS:
- U464.173
- DOI:
- -
- Abstract:
- In order to investigate the combustion cyclical variation of dual-fuel engine, tests were conducted on a methanol-diesel dual-fuel engine modified by an electronically controlled common rail diesel engine. The tests were carried out under four operation conditions. The first was conducted by changing co-combustion ratio under engine speed of 1 400 r/min, load ratio of 40% (51.6 kW) and the optimum timing of pilot-diesel injection. The second was conducted by changing load ratio under engine speed of 1 400 r/min, co-combustion ratio of 21.2% and the optimum timing of pilot-diesel injection. The third was conducted by changing engine speed under the torque of 220 N·m, co-combustion ratio of 39.6% and the optimum timing of pilot-diesel injection. The fourth was conducted by changing pilot-diesel injection timing under engine speed of 1 400 r/min, load ratio of 25% (32.84 kW) and co-combustion ratio of 37.26%. Effects of parameter variations on the peak pressure (pmax), the peak pressure-rise rate ((dp/dφ)max), the coefficient of cyclical variation of peak pressure (COVpmax) and the coefficient of cyclical variation of mean indicated pressure (COVIMEP) of the dual-fuel engine were studied. The results show that with the increase of co-combustion ratio, the peak pressure reduces a little and the rising-rate of peak pressure becomes larger. Combustion stability is poor and there is a large cyclical variation under large co-combustion ratio. With the increase of load ratio, the peak pressure increases, and its rising rate increases first and then decreases. As engine speed increases, the peak pressure becomes bigger with low rising-rate. When the load ratio or the speed increases, the combustion cyclical variation becomes smaller. As the injection timing is advanced, the peak pressure and its rising-rate increase. Properly advancing the injection timing under small load and big co-combustion ratio can improve the stability of combustion, while excessively advancing the injection timing can bring knockings.
Last Update: 2017-04-07