A Novel Pre-chamber Combustion System Combined with Fuel Reformation for Stable Lean-burn Operation
2022-01-0513
03/29/2022
- Event
- Content
- In order to improve thermal efficiency of gasoline engines, lean-burn operation with the pre-chamber was examined. To achieve stable operation with an air excess ratio of λ = 2.0 or higher, a new combustion technique that combines Pre-chamber combustion and fuel reforming was proposed. In the proposed system, a small amount of reforming gas containing hydrogen is supplied to the Pre-chamber to promote the combustion with an extremely lean mixture in the Pre-chamber. The combustion in the main chamber can be accelerated. NOx emissions are reduced due to the lean combustion in the Pre-chamber. In this study, the proposed system was demonstrated. Before the experiment, 1D engine cycle simulation was conduced to find the specifications and conditions of the engine to realized the proposed combustion concept. The amount of hydrogen injected was evaluated using the hydrogen volume fraction, VFH2. As a result, it was found that combustion concept can be realized with the hydrogen volume fraction, VFH2, in the Pre-chamber is about 4%. Next, the proposed Pre-chamber combustion system was experimentally examined using the single cylinder test engines. The experimental conditions were shown in Table 1. As a result, the lean limit for stable engine operation could be extended up to about λ=2.5 using the hydrogen supplied Pre-camber combustion.
- Citation
- Kuboyama, T., "A Novel Pre-chamber Combustion System Combined with Fuel Reformation for Stable Lean-burn Operation," SAE Technical Paper 2022-01-0513, 2022, .