石油产品.四变量公式法计算中间馏分燃料的十六烷指数

[中文适用范围]： 本文件规定了石油衍生中间馏分燃料十六烷指数的计算程序。计算值称为“四变量方程十六烷指数”。在本文件的其余部分中，“十六烷指数”一词均指四变量方程十六烷指数。本文件适用于含有来自焦油砂和油页岩的非石油衍生物的燃料。它不适用于纯碳氢化合物，也不适用于从煤中提取的馏分燃料。十六烷指数计算不考虑用于提高十六烷值的添加剂的影响。注 1 本文件最初是使用燃料矩阵开发的，其中一些燃料矩阵含有来自焦油砂和油页岩的非石油衍生物。注 2 十六烷指数不是表达十六烷值的替代方式；它是一种补充工具，使用时应充分考虑其局限性。注 3：当没有试验发动机直接测定十六烷值或发动机额定样品不足时，可使用十六烷指数估算柴油的十六烷值。 最适合于应用本文件的燃料特性范围如下： 燃料特性范围十六烷值 32.5 至 56,510 % (V/V) 蒸馏恢复温度，℃ 171 至 259 15℃时的密度，kg/m3805.0 至 895,050 % (V/V) 蒸馏恢复温度，℃ 212 至 30890 % (V/V) 蒸馏恢复温度，℃ 251 至 363 在十六烷值（32.5 至 56.5）范围内，对于 65% 的受检馏分燃料，通过十六烷指数方程进行预测的预期误差将小于±2 个十六烷值。对于性质不在此应用范围的燃料，误差可能会更大。由于观察到特定于样本的偏差，即使燃料的性质在推荐的应用范围内，预期误差也可能更大。因此，用户可以评估所需的预测一致性程度，以确定预测的适用性。注 4 对于含有 FAME（脂肪酸甲酯）的馏分燃料，观察到了特定于样本的偏差。 1  [外文原描述]： This document specifies a procedure for the calculation of the cetane index of middle-distillate fuels from petroleum-derived sources. The calculated value is termed the "cetane index by four-variable equation". Throughout the remaining text of this document, the term "cetane index" implies cetane index by four-variable equation. This document is applicable to fuels containing non-petroleum derivatives from tar sand and oil shale. It is not applicable to pure hydrocarbons, nor to distillate fuels derived from coal. Cetane index calculations do not take into account the effects from additives used to enhance the Cetane number. NOTE 1 This document was originally developed using a matrix of fuels, some of which contain non-petroleum derivatives from tar sands and oil shale. NOTE 2 The cetane index is not an alternative way to express the cetane number; it is a supplementary tool, to be used with due regard for its limitations. NOTE 3 The cetane index is used to estimate the cetane number of diesel fuel when a test engine is not available to determine this property directly, or when insufficient sample is available for an engine rating. The most suitable range of fuel properties for application of this document is as follows: Fuel property Range Cetane number 32,5 to 56,5 Density at 15 °C, kg/m 3 805,0 to 895,0 10 % ( V/V ) distillation recovery temperature, °C 171 to 259 50 % ( V/V ) distillation recovery temperature, °C 212 to 308 90 % ( V/V ) distillation recovery temperature, °C 251 to 363 Within the range of cetane number (32,5 to 56,5), the expected error of the prediction via the cetane index equation will be less than ±2 cetane numbers for 65 % of the distillate fuels examined. Errors can be greater for fuels whose properties fall outside this range of application. As a consequence of sample-specific biases observed, the expected error can be greater even when the fuel's properties fall inside the recommended range of application. Therefore, users can assess the required degree of prediction agreement to determine the fitness-for-use of the prediction. NOTE 4 Sample specific biases were observed for distillate fuels containing FAME (fatty acid methyl ester).