Compression diesel fuel

In a diesel engine, air is compressed to pressures of 1000 psi or greater. Upon compression, the air temperature increases to temperatures in the range of 600°F to 800°F (315.6°C to 426.7°C). At close to maximum compression, diesel fuel is injected into this hot, compressed air. Ignition of fuel within this environment is initiated whenever fuel components with the lowest autoignition temperature begin to combust. 

Alternative fuels fall into two general categories. The first class consists of fuels that are made from sources other than cmde oil but that have properties the same as or similar to conventional motor fuels. In this category are fuels made from coal and shale (see Fuels, synthetic). In the second category are fuels that are different from gasoline and diesel fuel and which require redesigned or modified engines. These include methanol (see Alcohol fuels), compressed natural gas (CNG), and Hquefted petroleum gas (LPG). 

All diesel fuels tend to contain trace water, expressed in parts per million (ppm). With the veiy high fuel injection pressures now used in electronically controlled diesel engine, fuel-filter/water separators are widely used, since water allowed to circulate freely through the injection system can result in seizure of components and erosion of injector orifice holes, and in extreme cases the high compressibility factor of water can blow the tip off of the fuel injector. 

Btu versus about 2.4 million Btti for a diesel fuel tank of the same size. Thus, the gas must be compressed and stored in a welded bottle-like tank at... 

The major advantage of Fischer Tropsch diesel, compared to natural gas, lies in its liquid nature. It does not need special infrastructure and compression like CNG does, and unlike LNG, once converted, it is a liquid fuel that can be treated like any other liquid fuel. However, because the GTL process is more complex than traditional refining, it requires low-cost natural gas priced at less than 1 per million BTUs to remain cost-competitive. Without stranded gas, sources sold at a large discount compared to crude oil, GTL diesel would be considerably more expensive than traditionally refined diesel fuel. 

Overlaying the bars that give the breakdown of cost to the operation (manufacturing, maintenance, retail) is the total energy cost. For central gaseous it includes an important contribution from delivery (diesel fuel) and retail (electricity for on-site compression). For a more extensive discussion, see the text. 

Diesel fuel fnel nsed for internal combnstion in diesel engines usually, that fraction which distills within the temperature range approximately 200 to 370°C. A general term covering oils used as fuel in diesel and other compression ignition engines. 

Many studies on the performances and emissions of compression ignition engines, fueled with pme biodiesel and blends with diesel fuel, have been conducted and are reported in the literature (Laforgia and Ardito, 1994). Fuel characterization data show some similarities and differences between biodiesel and petrodiesel fuels. The sulfur content of petrodiesel is 20 to 50 times that of biodiesel. Biodiesel has demonstrated a number of promising characteristics, including reduction of exhaust emissions. 

The production, processing, transportation, and compression of NG to the CNG fuel that is used by vehicles results in less environmental impact than the production, transportation, and processing of cmde oil and the transportation of gasoline or diesel to the service stations. COj emission of NG is lower than both diesel fuel and gasoline, which makes natural gas engines favorable also in terms of the greenhouse effect. 

FIGURE 16.42 Measured emissions of (a) particles (PM) and (b) NO, from more than 300 buses and heavy-duty trucks running on compressed natural gas (CNG), two diesel fuels, or alcohol fuels (E93, E95, and M100). The bars are the means and the boxes encompass the 95% confidence intervals. E93 = 93% ethanol, 5% methanol, 2% K-l kerosene E95 = 95% ethanol, 5% gasoline M100 = 100% methanol (adapted from Wang et al., 1997). 

Mixture Formation. The passage of fuel through the injection system is the first step in the formation of a fuel-air mixture. Flow is intermittent, and pressures may range from 100 to 1500 atmospheres, depending upon the type of system. Thus, the metering and delivery of the fuel are affected by pressure waves, the compressibility of the fuel, and the elasticity of the system. Flow under transient conditions in Diesel fuel injection systems has been studied and analyzed (35, 143) and methods have been developed for measuring the rate of fuel flow (34, 136) under these same conditions. 

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