To improve the energy utilization efficiency of internal combustion （IC） engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exer...To improve the energy utilization efficiency of internal combustion （IC） engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exergy balance model was built. The working processes of gasoline engine were simulated by using the GT-power. In this way, the required parameters were calculated and then gasoline engine exergy balance was obtained by programming on computer. On this basis, the influences of various parameters on exergy balance were analyzed. Results show that, the proportions of various forms of exergy in gasoline engine from high to low are irreversible loss, effective work, exhaust gas exergy and heat transfer exergy. Effective exergy proportion fluctuates with cylinder volumetric efficiency at full load, while it always increases with break mean effective pressure （BMEP） at part load. Exhaust gas exergy proportion is more sensitive to speed, and it increases with speed increasing except at the highest speed. The lower proportion of heat transfer exergy appears at high speed and high load. Irreversible loss is mainly influenced by load. At part load, higher BMEP results in lower proportion of irreversible loss; at full load, the proportion of irreversible loss changes little except at the highest speed.展开更多
为验证被动预燃室技术在商用缸内直喷(gasoline direct injection,GDI)发动机中的应用潜力,采用三阶段喷射策略研究了预燃室点火发动机在增压稀薄燃烧环境中的热效率、燃烧特性(累计放热量达到总放热量的50%对应的曲轴转角CA50、爆震指...为验证被动预燃室技术在商用缸内直喷(gasoline direct injection,GDI)发动机中的应用潜力,采用三阶段喷射策略研究了预燃室点火发动机在增压稀薄燃烧环境中的热效率、燃烧特性(累计放热量达到总放热量的50%对应的曲轴转角CA50、爆震指数和循环变动系数)和排放特性,建立了三维仿真模型进行模拟。结果表明,在高负荷条件下,平均爆震指数可控制在0.20~0.34 MPa之间,循环变动系数可控制在3.0%~3.5%之间;当指示平均有效压力(indi⁃cated mean effective pressure,IMEP)在1.0 MPa~1.4 MPa范围内,指示热效率均能达到40%以上;负荷增加时,氮氧化物呈下降趋势,碳氢化合物和一氧化碳排放略有增加。展开更多
基金Foundation item： Project（2011CB707201） supported by the National Basic Research Program of China Project（10JJ5058） supported by the Natural Science Foundation of Hunan Province, China
文摘To improve the energy utilization efficiency of internal combustion （IC） engine, exergy analysis was conducted on a passenger car gasoline engine. According to the thermodynamic theory of IC engine, in-cylinder exergy balance model was built. The working processes of gasoline engine were simulated by using the GT-power. In this way, the required parameters were calculated and then gasoline engine exergy balance was obtained by programming on computer. On this basis, the influences of various parameters on exergy balance were analyzed. Results show that, the proportions of various forms of exergy in gasoline engine from high to low are irreversible loss, effective work, exhaust gas exergy and heat transfer exergy. Effective exergy proportion fluctuates with cylinder volumetric efficiency at full load, while it always increases with break mean effective pressure （BMEP） at part load. Exhaust gas exergy proportion is more sensitive to speed, and it increases with speed increasing except at the highest speed. The lower proportion of heat transfer exergy appears at high speed and high load. Irreversible loss is mainly influenced by load. At part load, higher BMEP results in lower proportion of irreversible loss; at full load, the proportion of irreversible loss changes little except at the highest speed.
文摘为验证被动预燃室技术在商用缸内直喷(gasoline direct injection,GDI)发动机中的应用潜力,采用三阶段喷射策略研究了预燃室点火发动机在增压稀薄燃烧环境中的热效率、燃烧特性(累计放热量达到总放热量的50%对应的曲轴转角CA50、爆震指数和循环变动系数)和排放特性,建立了三维仿真模型进行模拟。结果表明,在高负荷条件下,平均爆震指数可控制在0.20~0.34 MPa之间,循环变动系数可控制在3.0%~3.5%之间;当指示平均有效压力(indi⁃cated mean effective pressure,IMEP)在1.0 MPa~1.4 MPa范围内,指示热效率均能达到40%以上;负荷增加时,氮氧化物呈下降趋势,碳氢化合物和一氧化碳排放略有增加。
