1.1 本试验方法涵盖了以公制(SI)单位，兆焦耳/千克为单位的恒定压力下净燃烧热的估算。 1.2 本试验方法纯粹是经验性的，仅适用于通过正常精炼工艺从常规原油中获得的液态烃燃料，这些燃料符合航空汽油或飞机涡轮和喷气发动机燃料的规格要求，其沸点范围和成分有限，如中所述 附注1 . 附注1: 只有当燃料属于明确定义的类别时，根据其苯胺点温度和密度估计碳氢化合物燃料的净燃烧热才是合理的，对于该类别，这些量之间的关系是从对该类别的代表性样品的精确实验测量中得出的。即使在这一类别中，也应该认识到单个燃料的估计值可能存在很大误差的可能性。JP-8燃料虽然没有经过实验测试，但具有与JP-5和Jet A燃料相似的特性，可以被认为是同一类别。用于建立本试验方法中提出的相关性的燃料类别由以下应用表示: 燃料 规格 航空汽油燃料: 规格 D910 GRED80,UL82,UL87,90,91,UL91,94,UL94,100/100LL/100VLL 规格 D6227 规格 D7547 规格 D7592 航空涡轮燃料: 规格 D6615 喷气机B，JP-4 MIL-DTL-5624 JP-5 MIL-DTL-5624 JP-8 MIL-DTL-83133 喷气机A，喷气机A-1 规格 D1655 规格 D7223 规格 D7566 1.3 净燃烧热也可通过试验方法估算 D1405 或 D3338 测试方法 D1405 需要计算取决于燃料类型的四个方程中的一个，其精度与本测试方法相当，而测试方法 D3338 需要计算航空燃料的单一方程，精度相当于该测试方法。 1.4 以SI单位表示的值将被视为标准值。本标准不包括其他计量单位。 1.5 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.6 本国际标准是根据世界贸易组织发布的关于制定国际标准、指南和建议的原则的决定中确立的国际公认的标准化原则制定的贸易技术壁垒委员会。 ======意义和用途====== 4.1 该测试方法旨在用作燃烧热的实验测定不可用且不能方便地进行的情况下的指南，并且估计值被认为是令人满意的。它不打算替代燃烧热的实验测量（ 附注2 ). 附注2: 试验方法中描述了总燃烧热和净燃烧热的实验测定程序 D240 和 D4809 . 4.2 净燃烧热是所有航空燃料性能的一个因素。因为飞机发动机的排气含有未冷凝的水蒸气，所以燃料在汽化水中释放的能量不能回收，必须从总燃烧热测定中减去以计算净燃烧热。对于高性能限重飞机，单位质量的净燃烧热和装载的燃油质量决定了总安全航程。飞机发动机的适当操作还要求每单位体积输送的燃料具有一定的最小净燃烧能量。 4.3 因为烃燃料混合物的燃烧热是混合物物理性质的缓慢变化的函数，所以混合物的燃烧热通常可以通过密度和苯胺点温度的简单现场测试以足够的精度估计，而无需量热法所需的精密设备。 4.4 无硫燃料净燃烧热的经验二次方程是通过最小二乘法从对燃料的精确测量中导出的，其中大多数符合中发现的燃料规范 附注1 并且被选择来覆盖一系列属性值。选择那些不符合规格的燃料是为了将密度和苯胺点温度的范围扩大到规格限值以上和以下，以避免最终效应。硫校正是通过对所测试的含硫燃料进行同时最小二乘回归分析而发现的。

1.1 This test method covers the estimation of the net heat of combustion at constant pressure in metric (SI) units, megajoules per kilogram. 1.2 This test method is purely empirical, and it is applicable only to liquid hydrocarbon fuels derived by normal refining processes from conventional crude oil which conform to the requirements of specifications for aviation gasolines or aircraft turbine and jet engine fuels of limited boiling ranges and compositions as described in Note 1 . Note 1: The estimation of the net heat of combustion of a hydrocarbon fuel from its aniline point temperature and density is justifiable only when the fuel belongs to a well-defined class for which a relationship between these quantities has been derived from accurate experimental measurements on representative samples of that class. Even in this class, the possibility that the estimates can be in error by large amounts for individual fuels should be recognized. The JP-8 fuel, although not experimentally tested, has properties similar to JP-5 and Jet A fuels and can be considered in the same class. The classes of fuels used to establish the correlation presented in this test method are represented by the following applications: Fuel Specification Aviation gasoline fuels: Specification D910 Grades 80, UL82, UL87, 90, 91, UL91, 94, UL94, 100/100LL/100VLL Specification D6227 Specification D7547 Specification D7592 Aviation turbine fuels: Specification D6615 Jet B, JP-4 MIL-DTL-5624 JP-5 MIL-DTL-5624 JP-8 MIL-DTL-83133 Jet A, Jet A-1 Specification D1655 Specification D7223 Specification D7566 1.3 The net heat of combustion can also be estimated by Test Methods D1405 or D3338 . Test Method D1405 requires calculation of one of four equations dependent on the fuel type with the precision equivalent to that of this test method, whereas Test Method D3338 requires calculation of a single equation for aviation fuel with a precision equivalent to that test method. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 This test method is intended for use as a guide in cases where an experimental determination of heat of combustion is not available and cannot be made conveniently, and where an estimate is considered satisfactory. It is not intended as a substitute for experimental measurements of heat of combustion ( Note 2 ). Note 2: The procedures for the experimental determination of the gross and net heats of combustion are described in Test Methods D240 and D4809 . 4.2 The net heat of combustion is a factor in the performance of all aviation fuels. Because the exhaust of aircraft engines contains uncondensed water vapors, the energy released by fuel in vaporizing water cannot be recovered and must be subtracted from gross heat of combustion determinations to calculate net heat of combustion. For high performance weight-limited aircraft, the net heat of combustion per unit mass and the mass of fuel loaded determine the total safe range. The proper operation of the aircraft engine also requires a certain minimum net energy of combustion per unit volume of fuel delivered. 4.3 Because the heat of combustion of hydrocarbon fuel-mixtures are slowly varying functions of the physical properties of the mixtures, the heat of combustion of the mixtures can often be estimated with adequate accuracy from simple field tests of density and aniline point temperature, without the elaborate apparatus needed for calorimetry. 4.4 The empirical quadratic equation for the net heat of combustion of a sulfur-free fuel was derived by the method of least squares from accurate measurements on fuels, most of which conformed to specifications for fuels found in Note 1 and were chosen to cover a range of values of properties. Those fuels not meeting specifications were chosen to extend the range of densities and aniline-point temperatures above and below the specification limits to avoid end effects. The sulfur correction was found by a simultaneous least-squares regression analysis of sulfur-containing fuels among those tested.