Study on Novel Combustion Technologies to Achieve “High-heels” Heat Release Rate Profile in a Higher-compression-ratio Diesel Engine
- Delivery
- Available on this site
- Format
- Price
- Non-members (tax incl.)：￥1,100 Members (tax incl.)：￥880
- Publication code
- 20239259
- Paper/Info type
- Other International Conferences
- Pages
- 1-11(Total 11 p)
- Date of publication
- Aug 2023
- Publisher
- JSAE & SAE
- Language
- English
- Event
- 2023 P, E&L
Detailed Information
| Category(E) | IC2 CI Injection and Combustion, High Efficiency, Optimization of Engine Operating Area |
|---|---|
| Author(E) | 1) Noboru Uchida, 2) Kazumasa Watanabe |
| Affiliation(E) | 1) New A.C.E. Institute Co., Ltd., 2) DENSO CORPORATION |
| Abstract(E) | For further increase in thermal efficiency of heavy-duty diesel engines, improvement of heat energy utilization must be essential. On one hand, increased compression (expansion) ratio could have an obvious potential to improve the thermal efficiency. However, it often results in higher cooling & mechanical losses and/or sluggish diffusion combustion by the deterioration of mixture formation under higher density and temperature condition. Furthermore, mechanical constraint on the peak cylinder pressure for each engine will limit the maximum compression ratio. On the other hand, flexible regulation of the heat release rate (HRR) profile could have more rooms to maximize the indicated thermal efficiency by overcoming these drawbacks relevant to higher compression ratio. Therefore, we have been investigating about the ideal (thermal-efficiency-optimum) HRR profile. Consequently, a new ideal HRR profile was proposed, which starts as a kind of delta shape to fulfil the isobaric cycle from TDC and is followed by the significant increase in HRR to reach the maximum cylinder pressure in the retarded timing. We call it as “High-heels” HRR profile from its two-step-increase delta shape. Then, to confirm the potential of the ideal High-heels HRR profile by utilizing a single-cylinder heavy-duty diesel engine, both numerical simulations and engine experiments were carried out with a variable fuel injection rate equipment, novel swirl-assisted combustion chamber shapes, and a tangentially-drilled-orifices nozzle as the technologies for modifying HRR profile. This study mainly discussed on the aim and the results of the latter two technologies. The experimental results confirmed slight improvements in the thermal efficiency as intended from the baseline, even though the maximum HRR in the late part of combustion has not achieved the target value with the integrated technologies yet. |
