复合供气压缩着火天然气发动机的试验研究

Experimental Study on Compression Ignition Engine with Natural Gas Compound Supply

设计开发的天然气发动机压缩着火燃烧系统采用球形涡流室式燃烧室结构及天然气复合供气系统,通过台架试验研究了不同天然气供气方式、进气加热温度、高压供气定时和高、低压供气比例对着火燃烧和排放的影响.结果表明,高压供气定时、高低压供气比例、进气加热温度对天然气压燃和排放的影响均存在最优值;与天然气低压供气方式相比较,复合供气方式实现天然气发动机的着火起动需要较高的辅助加热条件;但是在扩展发动机运转范围方面具有明显优势.

The designed combustion system conisists of a ball-shaped swirl combustion chamber and a compound fuel supply system. The factors affecting combustion and emission characteristics are explored on a compression ignition CNG compression natural gasengine,including CNG supply methods,charge air temperature, the timing of high pressure injection and the ratio of high/low pressure injection quantity. The results show that there exist optimal values with the above factors, and that compared with CNG low-pressure injection method, starting-up can be achieved with the compound supply method at a higher charge air temperature, while the operation range of the latter method is wider than that of the former.