Diesel injection

Water pump seals, hoses for air-conditioning systems, seals in cooling systems and covers in diesel injection systems... 

Lacey, P. I., and Lestz, S. J. 1992a. Effect of Low-Lubricity Fuels on Diesel Injection Pumps—Part I Field Performance. SAE Techn. Paper Ser. Warrendale PA Society of Automotive Engineers (Paper No. 920823). 

The kinetics of the selective catalytic reduction of nitric oxides (NOx) on a proprietary high temperature catalyst with diesel as the reductant have been studied. The objective was to derive a kinetic model that can be used for real time simulation of the catalyst. In the extension, the real time simulation will be used when controlling the injeetion of reductant. This is a requirement for achieving a high efficiency and a low fuel penalty. The response time and the NOx conversion level upon transient diesel injection was found to be dependent on the temperature. At temperatures below 570 K very low or no NOx conversion was observed. Above 570 K a small conversion was observed. No direct response upon diesel injection could be distinguished and the NOx conversion was independent on the hydrocarbon concentration. As the temperature was increased the response became apparent and then faster and the conversion level gradually became more dependent on the hydrocarbon concentration. Above 700 K the response was immediate (response time less than 15 s) and the conversion level was directly dependent on the hydrocarbon concentration. It was concluded that the NOx reduction proceeds via the formation of a hydrocarbon intermediate and the successive reaction between the hydrocarbon intermediate and NOx. When this reaction mechanism was modeled mtiny features of the catalyst behaviour were reproduced. 

Figure 1 shows the hydrocarbon concentration at the catalyst inlet and outlet during the first and the second run of the test cycle. The hydrocarbon conversion during diesel injection varied from 40% at low temperatures, to 85% at high temperatures. The response in hydrocarbon concentration at the outlet when diesel was injected was slow at low temperatures and fast at high temperatures. When the injection was interrupted a tailing was observed that was more pronounced at lower temperatures. This indicates that the hydrocarbon both adsorb and desorb from the catalyst. 

An interesting trend can be observed when examining the catalyst behaviour at different temperatures. At temperatures below 570 K very low or no NOx conversion was observed. Above 570 K a small NOx conversion was observed. No direct response upon diesel injection could be distinguished and the conversion was independent on the amount of hydrocarbon injected. As the temperature was increased the response became apparent and then faster and the conversion level gradually became dependent on the amount of injected diesel. Above 700 K the response was immediate and the conversion level was directly dependent on the amount of injected diesel. 

Figure 5 shows the observed and the simulated NOx concentration at the catalyst outlet during the second run of the test cycle. The standard deviation for the residual is 33 ppm or 8% of the mean NOx concentration. The model manages to predict the NOx conversion that onsets before diesel injection in the beginning of the 20-30 minutes and the 50-60 minutes interval. During injection in the 0-10 minutes interval and during the second injection in the... 

Sidhu, S. K. Packaging Very High Pressure Transducers from Common Rail Diesel Injection Systems, SAE Technical Paper 982020. 

Kong, J. and Bae, C. (2009) Effect of tapered nozzle hole on spray characteristics of high pressure diesel injection. Paper Presented at the International Annual Conference on Liquid Atomization and Spray Systems (ICLASS 2009), Vail. 

Blokkeel, G., Demoulin, F. X., Borghi, R. ICM). Modeling of two-phase flows An Eulerian model for diesel injection (Thermo-and-fluid dynamics process in diesel engines, Vol. 2). Berlin Springer. 

The diesel engine takes in and compresses the air. The fuel is injected into the cylinder in atomized form at the end of the compression stroke and is vaporized in the air. Ignition begins by auto-ignition in one or several zones in the combustion chamber where the conditions of temperature, pressure and concentration combine to enable combustion to start. 

The necessity of carrying out injection at high pressure and the atomization into fine droplets using an injector imposes very precise volatility characteristics for the diesel fuel. French and European specifications have established two criteria for minimum and maximum volatility therefore, the distilled fraction in volume % should be ... 

For a long time the official specifications for diesel fuel set only a mciximum viscosity of 9.5 mm /s at 20°C. Henceforth, a range of 2.5 mm /s minimum to 4.5 mm /s maximum has been set no longer for 20°C but at 40°C which seems to be more representative of injection pump operation. Except for special cases such as very low temperature very fluid diesel fuel and very heavy products, meeting the viscosity standards is not a major problem in refining. 

The density of heavy fuels is greater than 0.920 kg/1 at 15°C. The marine diesel consumers focus close attention on the fuel density because of having to centrifuge water out of the fuel. Beyond 0.991 kg/1, the density difference between the two phases —aqueous and hydrocarbon— becomes too small for correct operation of conventional centrifuges technical improvements are possible but costly. In extreme cases of fuels being too heavy, it is possible to rely on water-fuel emulsions, which can have some advantages of better atomization in the injection nozzle and a reduction of pollutant emissions such as smoke and nitrogen oxides. 

Tables 5.29 and 5.30 show an example of the effects of hydrotreated diesel fuels on a diesel passenger car already having a low level of pollution owing to technical modifications such as sophisticated injection and optimized combustion. In the standard European driving cycle (ECE + EUDC), between...

B. M. Bertilsson, "Regulated and Unregulated Emissions from an Alcohol-Pueled Diesel Engine with Two Separate Euel Injection Systems," 5th Int. Symp. on AlcoholEuel Technology (Auckland, New Zealand, May 13—18, 1982) Vol. 3. 

Viscosity. For optimum performance of diesel engine injector pumps, the fuel should have the proper viscosity. Too low viscosity results in excessive injector wear and leakage. Viscosity that is too high may cause poor atomisation of the fuel upon injection into the cylinders. 

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