基于熵方法的柴油机试验数据粗大误差分析

Analysis of gross errors of diesel test data based on entropy method

在四缸增压中冷柴油机上进行国标柴油试验,研究了不同批次国标柴油在柴油机上的经济性及排放性,同时引入测量信息论中熵判别方法计算测试样本的熵及不确定度,判别试验数据在置信区间内是否含有粗大误差。研究表明:在处理小样本数据时,熵判别方法可以对数据进行有效评价。本研究中,在1 600rpm且置信度为95%时,各工况燃油消耗率的置信区间分别为896.25±8.97、324.58±3.68、255.17±2.36、234.58±2.40、224.24±2.74;NOX排放的置信区间分别为232.00±22.81、492.86±32.24、844.43±66.86、1075.00±60.88、1371.71±78.37;排气温度的置信区间分别为161.00±8.48、180.29±8.31、231.43±8.27、300.86±9.83、364.71±10.47。

Tests were done on a four-cylinder turbocharged and intercooled diesel engine with different batches of national standard diesel burned to research the engine emissions and economy performance,while measurement information theory entropy was introduced for calculating entropy and uncertainty of test samples to discriminate if there was gross error.Studies showed that：dealing with small sample data,entropy discrimination method could effectively evaluate them.When operating conditions at 1600 rpm and confidence level was 95%,the confidence intervals of fuel consumption rate were 896.25 ±8.97,324.58±3.68,255.17±2.36,234.58±2.40 and 224.24±2.74;while the confidence intervals of NOx emission were 232.00±22.81,492.86±32.24,844.43±66.86,1075.00±60.88 and 1371.71±78.37;the confidence intervals of exhaust temperature were 161.00±8.48,180.29±8.31,231.43±8.27,300.86±9.83 and 364.71±10.47.