压缩空气-燃油混合动力排气能量回收利用

Compressed-air hybrid engine for exhaust energy recovery based on medium mixing

提出基于工质混合的压缩空气-燃油混合动力,利用文丘里管混合内燃机排气和压缩空气,回收利用内燃机排气能量.建立混合动力热力学模型,分析压缩空气发动机转速、压缩空气压力和质量流量以及内燃机转速和负荷对混合动力有效效率的影响规律.研究结果表明:压缩空气发动机转速越低,混合动力有效效率越高;内燃机转速和负荷对混合动力有效效率的影响规律与原内燃机的变化趋势一致;内燃机排气提前角存在一个最佳值,最佳排气提前角受内燃机排气压力和压缩空气压力的共同影响,内燃机排气压力升高,最佳排气提前角减小;压缩空气压力升高,最佳排气提前角增大.

A compressed air hybrid engine concept based on the medium mixing was proposed in order torecover the exhaust energy. A venturi pipe was utilized to mix the exhaust gas and compressed air. Thenthe thermodynamic model of hybrid engine was conducted. The impact of some technical parameters on theeconomic performance of hybrid engine was analyzed. The effect of some assumptions on the performanceof hybrid engine was discussed. Results showed that the braking efficiency of hybrid engine increased asthe compressed air engine speed decreased. The influence of internal combustion engine speed and load tothe braking efficiency of hybrid engine was same to the conventional internal combustion engine. Therewas an optimal exhaust valve open timing of internal combustion engine to achieve a highest braking efficiencyof hybrid engine. The optimal exhaust valve open timing was influenced by internal combustionengine exhaust pressure and compressed air pressure. The increase of the internal combustion engine exhaustpressure or the decrease of the compressed air pressure both leaded to a decrease of the optimal exhaustvalve open timing.