Significance and Use
This test method is intended for use as a guide in cases where 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. Table 1 shows a summary for the range of each variable used in developing the correlation. The mean value and an estimate of its distribution about the mean, namely the standard deviation, is shown. This indicates, for example, that the mean density for all fuels used in developing the correlation was 779.3 kg/m3 and that two thirds of the samples had a density between 721.4 and 837.1 kg/m3, that is, plus or minus one standard deviation. The correlation is most accurate when the values of the variables used are within one standard deviation of the mean, but is useful up to two standard deviations of the mean. The use of this correlation may be applicable to other hydrocarbon distillates and pure hydrocarbons; however, only limited data on non-aviation fuels over the entire range of the variables were included in the correlation.
Note 4—The procedures for the experimental determination of the gross and net heats of combustion are described in Test Methods D 240 and D 4809.
The calorimetric methods cited in Note 4 measure gross heat of combustion. However, net heat is used in aircraft calculations because all combustion products are in the gaseous state. This calculation method is based on net heat, but a correction is required for condensed sulfur compounds.
TABLE 1 Mean and Standard Deviation of the Variables
|Aromatics, volume %||13.5||23.9|
|Density, kg/m3 [°API]||779.3 [50.0]||58.0 [13.5]|
|Volatility, °C [°F]||171.11 ||57.2 |
|Heat of combustion, MJ/kg [Btu/lb]||43.421 [18 668]||0.862 |
1.1 This test method covers the estimation of the net heat of combustion (megajoules per kilogram or [Btu per pound]) of aviation gasolines and aircraft turbine and jet engine fuels in the range from 40.19 to 44.73 megajoules per kilogram or [17 280 to 19 230 Btu per pound]. The precision for estimation of the net heat of combustion outside this range has not been determined for this test method.
1.2 This test method is purely empirical and is applicable to liquid hydrocarbon fuels that conform to the specifications for aviation gasolines or aircraft turbine and jet engine fuels of grades Jet A, Jet A-1, Jet B, JP-4, JP-5, JP-7, and JP-8.
Note 1—The experimental data on heat of combustion from which the Test Method D 3338 correlation was devised was obtained by a precision method similar to Test Method D 4809.
Note 2—The estimation of the net heat of combustion of a hydrocarbon fuel is justifiable only when the fuel belongs to a well-defined class for which a relation between heat of combustion and aromatic and sulfur contents, density, and distillation range of the fuel has been derived from accurate experimental measurements on representative samples of that class. Even in this case, the possibility that the estimates may be in error by large amounts for individual fuels should be recognized. The fuels used to establish the correlation presented in this method are defined as follows:
|Aviation gasoline—Grades 100/130 and 115/145 (1, 2) |
|Kerosines, alkylates, and special WADC fuels (3) |
|Pure hydrocarbons—paraffins, naphthenes, and aromatics (4) |
|Fuels for which data were reported by the Coordinating Research Council (5).|
Note 3—The property ranges used in this correlation are as follows:
|Aromatics—from 0 to 100 mass %|
|API Gravity—from [25.7 to 81.2°API]|
|Volatility—from [160 to 540°F], average boiling point|
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.3.1 Although the test method permits the calculation of net heat of combustion in either SI or inch-pound units, SI units are the preferred units.
1.3.2 The net heat of combustion can also be estimated in inch-pound units by Test Method D 1405 or in SI units by Test Method D 4529. Test Method D 1405 requires calculation of one of four equations dependent on the fuel type with a precision equivalent to that of this test method. Test Method D 4529 requires calculation of a single equation for all aviation fuels with a precision equivalent to that of this test method. Unlike Test Method D 1405 and D 4529, Test Method D 3338 does not require the use of aniline point.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D86 Test Method for Distillation of Petroleum Products at Atmospheric Pressure
D240 Test Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter
D1266 Test Method for Sulfur in Petroleum Products (Lamp Method)
D1298 Test Method for Density, Relative Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method
D1319 Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsorption
D1405 Test Method for Estimation of Net Heat of Combustion of Aviation Fuels
D1552 Test Method for Sulfur in Petroleum Products (High-Temperature Method)
D2622 Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry
D2887 Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography
D3120 Test Method for Trace Quantities of Sulfur in Light Liquid Petroleum Hydrocarbons by Oxidative Microcoulometry
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
D4294 Test Method for Sulfur in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence Spectrometry
D4529 Test Method for Estimation of Net Heat of Combustion of Aviation Fuels
D4809 Test Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter (Precision Method)
D5453 Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
D6379 Test Method for Determination of Aromatic Hydrocarbon Types in Aviation Fuels and Petroleum Distillates--High Performance Liquid Chromatography Method with Refractive Index Detection
Energy Institute Standard
IP436 Test Method for Determination of Aromatic Hydrocarbon Types in Aviation Fuels and Petroleum DistillatesHigh Performance Liquid Chromatography Method with Refractive Index Detection
aviation fuel; gross heat of combustion; heat energy; heat of combustion; heating tests; net heat of combustion; Aviation fuels (heat of combustion); Combustion--petroleum products; Heating tests--petroleum products;
ICS Number Code 75.160.20 (Liquid fuels)
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Citing ASTM Standards
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