A New Criterion to Determine the Start of Combustion in Diesel Engines
A New Criterion to Determine the Start of Combustion in Diesel Engines
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DOI：
10.1115/1.2179471
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发表时间：
2004
影响因子：
1.5
通讯作者：
T. Katrašnik;F. Trenc;Samuel Rodman Opresnik
中科院分区：
文献类型：
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作者：
T. Katrašnik;F. Trenc;Samuel Rodman Opresnik
提出了一种由柴油机缸内压力图判断燃烧开始的新判据。它被定义为气缸压力相对于曲柄角的三阶导数的最大值。该标准比其他先前发布的基于压力诊断的标准更精确地声明SOC。这一事实在分析上得到了证明，并且从实验数据的分析中可以看出。除了其准确性之外，它还足够稳健，以允许在处理大量循环的压力数据期间自动评估SOC。通过将热力学第一定律应用于发动机气缸分析，发现缸内压力相对于曲柄角的三阶导数是从缸内压力图确定SOC的最合适的标准。随后，通过对不同转速和负荷下缸内压力图的实验数据分析，验证了该准则的有效性。为了评估的放热率（ROHR），这形成了实验验证的基础，缸内压力图处理的计算机代码的基础上的热力学第一定律。气缸压力是用先进的压电传感器测量的，分辨率为0.1 deg CA。采用电容式上止点传感器确定上止点。由于所开发的方法的分析基础及其通过高度准确的实验数据的验证，可以得出结论，新的标准是可信的SOC的测定。
A new criterion for the determination of the start of combustion (SOC) from the diesel engine in-cylinder pressure diagram was developed. It is defined as the maximum of the third-order derivative of the cylinder pressure with respect to the crank angle. This criterion declares SOC more precisely than other previously published criteria based on pressure diagnostics. This fact was proven analytically and was discernable from the analysis of the experimental data. Besides its accuracy it is also robust enough to allow automatic evaluation of the SOC during processing of the pressure data for a large number of cycles. By applying the first law of thermodynamics analysis to the engine cylinder it was discovered that the third-order derivative of the in-cylinder pressure with respect to the crank angle is the most suitable criterion for determination of the SOC from the in-cylinder pressure diagram. Subsequently, the criterion was validated through experimental data analysis of the in-cylinder pressure diagrams for various engine speeds and loads. In order to evaluate the rate of heat release (ROHR), which formed the base for the experimental validation, in-cylinder pressure diagrams were processed with a computer code based on the first law of thermodynamics. The cylinder pressure was measured with an advanced piezoelectric sensor at the resolution 0.1 deg CA. Top dead center was determined with the capacitive top dead center sensor. Due to the analytic foundation of the developed method and its validation through highly accurate experimental data it can be concluded that new criterion is credible for the determination of the SOC.