Effects of mean piston speed, equivalence ratio and cylinder wall temperature on performance of an Atkinson engine
Effects of mean piston speed, equivalence ratio and cylinder wall temperature on performance of an Atkinson engine
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DOI：
10.1016/j.mcm.2010.12.015
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发表时间：
2011-03-01
影响因子：
--
通讯作者：
Ebrahimi, Rahim
中科院分区：
文献类型：
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作者：
Ebrahimi, Rahim
用有限时间热力学方法分析了空气标准阿特金森循环的性能。该模型考虑了工质比热容比与温度的线性关系、按活塞平均速度计算的摩擦损失、用压缩效率和膨胀效率描述的内不可逆性以及传热损失。通过详细的数值算例，导出了输出功率与压缩比、输出功率与热效率之间的关系。结果表明：当压缩比小于一定值时，发动机输出功率随平均活塞转速的增加而减小;当压缩比大于一定值时，发动机输出功率随平均活塞转速的增加先增大后减小。随着压缩比的进一步增加，平均活塞速度的增加导致输出功率的降低。在整个压缩比范围内，输出功率随缸壁温度的升高而增大，随当量比的增大先增大后减小。当考虑实际阿特金森发动机的设计时，这项调查的结论是重要的。(C)2010爱思唯尔有限公司版权所有。
The performance of an air standard Atkinson cycle is analyzed using finite-time thermodynamics. In the model, the linear relation between the specific heat ratio of the working fluid and its temperature, the friction loss computed according to the mean velocity of the piston, the internal irreversibility described by using the compression and expansion efficiencies and the heat transfer loss are considered. The relations between the power output and the compression ratio and between the power output and the thermal efficiency are derived by detailed numerical examples. The results show that if the compression ratio is less than a certain value, the power output decreases with increasing mean piston speed, while if the compression ratio exceeds a certain value, the power output first increases and then starts to decrease with increasing mean piston speed. With further increase in the compression ratio, the increase of mean piston speed results in decreasing the power output. Throughout the compression ratio range, the power output increases with increasing cylinder wall temperature while it first increases and then starts to decrease with the increase of equivalence ratio. The conclusions of this investigation are of importance when considering the designs of actual Atkinson engines. (C) 2010 Elsevier Ltd. All rights reserved.