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Calculated Ignition Index
The Calculated Ignition Index (CII) is an index of the ignition quality of residual fuel oil. The running of all internal combustion engines is dependent on the ignition quality of the fuel. For spark-ignition engines the fuel has an octane rating. For diesel engines it depends on the type of fuel, for distillate fuels the cetane numbers are used. Cetane numbers are tested using a special test engine and the existing engine was not made for residual fuels. For residual fuel oil two other empirical indexes are used CII and Calculated Carbon Aromaticity Index (CCAI). Both CII and CCAI are calculated from the density and viscosity, kinematic viscosity of the fuel. Definition Formula for CII: CII = (270.795 + 0.1038T)-0.254565D+23.708 \log \log(V+0.7)\, Where: D = density at 15°C (kg/m3) V = viscosity (cST) T = viscosity temperature (°C) Use CII was designed to give out numbers in the same order as the cetane index for distillate fuels. Combustion {{chemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cetane Number
Cetane number (cetane rating) is an indicator of the combustion speed of diesel fuel and compression needed for ignition. It plays a similar role for diesel as octane rating does for gasoline. The CN is an important factor in determining the quality of diesel fuel, but not the only one; other measurements of diesel fuel's quality include (but are not limited to) energy content, density, lubricity, cold-flow properties and sulphur content.Werner Dabelstein, Arno Reglitzky, Andrea Schütze and Klaus Reders "Automotive Fuels" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2007, Wiley-VCH, Weinheim. Definition The cetane number (or CN) of a fuel is defined by finding a blend of cetane and isocetane with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel alpha-methylnaphthalene, which was assigned a cetane number of 0. Once the blend is known, the cetane number is calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calculated Carbon Aromaticity Index
The calculated carbon aromaticity index (CCAI) is an index of the ignition quality of residual fuel oil. The running of all internal combustion engines is dependent on the ignition quality of the fuel. For spark-ignition engines the fuel has an octane rating. For diesel engines it depends on the type of fuel, for distillate fuels the cetane numbers are used. Cetane numbers are tested using a special test engine and the existing engine was not made for residual fuels. For residual fuel oil two other empirical indexes are used: CCAI and Calculated Ignition Index The Calculated Ignition Index (CII) is an index of the ignition quality of residual fuel oil. The running of all internal combustion engines is dependent on the ignition quality of the fuel. For spark-ignition engines the fuel has an octane rating ... (CII). Both CCAI and CII are calculated from the density and kinematic viscosity of the fuel. Definition Formula for CCAI: CCAI=D-140.7 \log (\log (V+0.85))-80.6-210 \ln ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically, density is defined as mass divided by volume: : \rho = \frac where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate – this quantity is more specifically called specific weight. For a pure substance the density has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure. To simplify comparisons of density across different syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the internal frictional force between adjacent layers of fluid that are in relative motion. For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's axis than near its walls. Experiments show that some stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion. For a tube with a constant rate of flow, the strength of the compensating force is proportional to the fluid's viscosity. In general, viscosity depends on a fluid's state, such as its temperature, pressure, and rate of deformation. However, the dependence on some of these properties ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
