摘要
以WP12重型柴油机为研究对象,通过涡端旁通阀调整两级增压系统的能量分配比例,进而影响工况的当量比,协调排放量与热效率之间的矛盾。实验结果表明:随着涡轮端旁通阀开度的增加,高压级涡轮膨胀比和高压级压气机增压比均减小,进气流量减少;在低转速工况下,进气量的减小导致碳烟排放恶化,有用功明显减小,而换气负功变化微弱,热效率下降;在中高转速工况下,当涡轮端旁通阀开启8%时,排放基本不恶化,换气负功大幅减少是促使柴油机有效热效率提高的主要原因。
In this study,a turbine bypass valve was used to adjusting the energy distribution ratio of two-stage turbocharger system and fuel air equivalence ratio,and the contradiction between emissions and thermal efficiency was coordinated in a WP12 heavy duty diesel engine. The research showed that with the increase of the turbine bypass valve,the expansion ratio and pressure ratio of the high pressure stage turbocharger were reduced. Then the intake air flow rate was also reduced. The reducing intake air resulting in soot emissions deterioration and useful work was significantly reduced. However,it had slight changes with air exchange work. All these causes the decline in thermal efficiency when diesel working in low-speed conditions. It also showed that adjusting turbine bypass valve to 8% in middle or high speed conditions could increase effective thermal efficiency,and keep emission without deterioration.
出处
《西华大学学报(自然科学版)》
CAS
2014年第3期60-65,共6页
Journal of Xihua University:Natural Science Edition
基金
四川省教育厅项目(11ZA284)
四川省教育厅项目(13ZB0022)
关键词
两级涡轮增压
旁通阀
有效热效率
进气压力
排气背压
two-stage turbocharger
bypass valve
effective thermal efficiency
intake pressure
backpressure