FI106885B - Method of Injecting Fuel into the Cylinder of the Diesel-Type Impact Piston Engine Cylinder and Injector Nozzle Arrangement - Google Patents

Description

1 106885

The invention relates to a method of injecting fuel into a cylinder of a diesel engine according to the preamble of claim 1. The present invention relates to a method for injecting fuel into a combustion chamber of a diesel piston piston combustion engine and to an injection nozzle assembly. The invention further relates to a device for injecting fuel into a cylinder of a diesel engine according to the preamble of claims 5 and 6.

EP 0 586 775 A1 discloses a method as well as a system 10 for injecting fuel in diesel engines. The diesel engine, and thus also the aforementioned, has considerable nitrogen monoxide (NOx) emissions during use.

This emission is due to the high combustion temperature, which causes some of the nitrogen in the combustion air to oxidize to nitrogen monoxide (NOx) during combustion. Another reason for the emission of nitrogen oxides is that the diesel combustion engines, especially the large diesel engines, have a low rotational speed during operation, which accelerates the formation of nitrogen monoxides because sufficient time is available for the NOx formation process to actually run.

It is an object of the present invention to provide a method and apparatus for reducing NOx formation in diesel engines to keep nitrogen monoxide (NOx) emissions from combustion processes low.

This object is achieved according to the invention by the method according to claim 25 1 and the injection nozzle arrangement according to claim 5. Sub-claims 2-3 refer to other preferred embodiments of the invention.

the method according to the invention, in which fuel is injected into the diesel structure type reciprocating internal combustion engine cylinder into the combustion chamber 30 consists of the percussion piston moves towards the combustion chamber for combustion air swirl flow and ulostuieva spray nozzle fuel spray is injected into the case partly forward and partly with respect to the counter direction of the vortex flow, wherein the combustion air is mixed with the flue gas penetrates in the forward direction through an outlet of the fuel jet, and the flue gas is provided by the upstream and downstream fuel jet.

2 106885

The process according to the invention has the advantage that the combustion time is slower due to the flue gas acting as an inert gas, which lowers the combustion temperature. Another advantage can be seen in the fact that the flue gas traps heat as an inert gas, whereby the combustion temperature of the fuel jet 5 penetrated by the flue gas is reduced. Another advantage can be seen in the fact that the upstream fuel jet mixes quite well with the combustion air, which has a favorable effect on the formation of a mixture of fuel, air and flue gas. Said phenomena reduce the combustion temperature and thus also the formation of NOx. These phenomena are particularly evident in the case of low-speed diesel-fueled engines, where the combustion of the fuel occurs shortly after the start of injection. Thus, flue gas is present almost throughout the injection and the formation of the mixture.

Until now, fuel injection has not been followed by professionals in the opposite direction, since it was known that such injection reduces the efficiency of a diesel-15 internal combustion engine. The process according to the invention has the advantage that the formation of NOx is very strongly reduced, whereas the efficiency is not significantly or only insignificantly reduced.

The process according to the invention has the additional advantage that the formation of NOx depends on the amount of fuel injected in the upstream direction of the vortex flow. The more fuel injected in the upstream direction of the vortex flow, the more NOx formation will be reduced. In addition, injection nozzles which differ in NOx formation can be made.

The invention will now be described with reference to several embodiments; In Figure 25, Figure 1 schematically shows a longitudinal section of a cylinder including injection nozzles for carrying out the method according to the invention, Figure 1a shows an overview Fig. 1d shows a general view of the orifices in the injector nozzle, 3 106885 Fig. 2 shows a diagram of NOx formation and efficiency with respect to eddy flow as a function of the amount of fuel injected in the opposite direction.

Fig. 1 shows a cylinder 2 of a multi-cylinder and slow-running, diesel-powered, 2-stroke piston combustion engine, not shown in greater detail herein, with an upwardly movable piston 8. The piston 8 defines with the cylinder head 2b mounted on the cylinder 2. a combustion chamber 1 into which liquid fuel, namely diesel or heavy fuel oil, is injected by means of injection nozzles 13, as described below. A drain valve (not shown) is disposed in the center of the blade cover 2b of cylinder 10, whereby a longitudinal flushing occurs at the beginning of the upward movement of the piston 8 in cylinder 2. The cylinder wall 2 has an inlet port through which combustion air enters the interior of the combustion chamber 1, not shown, whereby the inlet openings are realized and directed so as to cause a swirl of incoming combustion air to form inside the combustion chamber 1.

The injection nozzle 13 has a nozzle needle 17 which is pressed against the stop surface 16 by the closing spring 18. Below the stop surface 16 there is a closed hole from which the injection holes 12 exit and end in the combustion chamber 1. Above the stop surface 16, the nozzle housing has a pressure chamber 10 connected by a pressure line 19 20 to the injection pump 20 to supply fuel from the fuel tank. In the injection stage of the injector nozzle 18, the pressure of the fuel introduced through the conduit 19 to the pressure chamber 10 is so high that the closing force of the spring 18 is exceeded and the nozzle needle 17 rises up from the counter surface 16. A conduit 22 is connected to the housing of the injector nozzle 13 to drain the leakage fuel. The cylinder 2 has a centerline 2a extending axially to the cylinder along which the center of the cylinder head 2b extends. The injection nozzle 18 has a centerline 3a extending axially to the injection nozzle 18 and centered thereon.

Fig. 1a shows a view of the combustion chamber 1 of the three injection nozzles 3 located on the cylinder head 2b. Here, only the injection holes 12 of the injection nozzles 3 shown schematically in the jet-shaped formations 6a, 6b, 6c are injected into the combustion chamber 1, and the outlet direction 5a, 5b, 5c from the fuel injection holes 12 is shown. Fuel injection is shown by way of example only in one injection nozzle 3. 35 But each injection nozzle is injected with fuel, preferably by using three identical injection nozzles, which are placed in the same manner as each of the injection nozzles 3, formations 6a, 6b, 6c.

By adjusting the inlet gap in the wall of the cylinder 2, a vortex movement is produced in the combustion air entering the combustion chamber 1. In the upward movement of the working piston 8, the vortex flow of the combustion air is further influenced, whereby the direction of the vortex flow 4 is indicated by an arrow. The jet-shaped formations 6a, 6b, 6c in the combustion chamber 1 normally deviate due to the vortex flow 4 with respect to the fuel outlet direction 5a, 5b, 5c from the injection holes 12.

1a, the center line 2a of the cylinder 2 and the center line 3a of the injection nozzle 18 can also be observed perpendicular to the direction of observation. The reference line 5 extending perpendicularly through the center line 2a and the centerline 3a defines a line with respect to which the angle of the outlet directions 5a, 5b, 5c is defined. The angle of the exit direction 5a is 0 °, the angle of the exit directions 5b and 5c is a1 or a2, whereby the angles in this representation increase clockwise. The outlet directions 5b and 5c are marked downstream of the vortex flow 4, whereas the outlet direction 5a is marked to run perpendicular to the vortex flow 4.

In Figure 1b, the injection nozzles 3 are arranged in the burner-20 1 in the same manner as in Figure 1a. However, the injection nozzle 3 shown in Fig. 1b further has injection holes 12 having an outlet direction 5d, 5e, 5f extending at an angle α3, a4 or cx5, whereby these angles increase counterclockwise relative to the reference line 5 in this disclosure. In the present publication, these outlet openings 5d, 5e and 5f are referred to in the opposite direction to the vortex flow 4.

Fig. 1c shows a section through an injector nozzle 3 whose fuel injection holes 6a, 6b, 6d are injected into the combustion chamber 1 by means of the injection holes 12, which are jet-shaped formations which burn and thus partly consist of fuel and partly combustion products 30 such as smoke. The development of the jet-shaped formations 6a, 6b, 6c is strongly influenced by the vortex flow 4. The fuel jet 6d injected in the opposite direction to the vortex flow produces flue gas which is effectively mixed with the further supplied air and the jet stream 6b and less oxygen is present during the combustion of the material jets 6a, 6b. The flue gas causes the combustion to take place at a slower time, which lowers the temperature of the fuel jet 6a, 6b. In addition, the flue gas traps heat, which further reduces the combustion temperature of the fuel jet that penetrates the flue gas. The lower combustion temperature of the fuel jet 6a, 6b thus achieved results in less NOx formation. Of course, the downstream fuel jet 6b also acts approximately perpendicularly to the eddy jet outward jet fuel jet 6a, since the jet stream 4 also transmits substantially less of this fuel jet 6a, mixing of flue gas with fresh combustion air.

The method according to the invention is based on spraying at least one fuel jet 6b coming out of the injection nozzle 3 with respect to the vortex flow 4, 6a, 6d with respect to the direction of the vortex flow 4 to the downstream fuel jets 6a and / or 6b, whereby the flue gas affects the combustion process of the downstream fuel jet 6a and / or 6b.

Injection nozzle 3 may be constructed in many different ways so that it can operate as described above. Specifically, the injection holes 12 can be mounted in many different ways on the injection nozzle 3 to achieve this effect, and the injection nozzle 3 can also be fitted in many different ways on the cylinder head 2b to inject some of the fuel upstream of the vortex current **. Figure 1d shows an exemplary embodiment of an arrangement of the outlet openings 7a-7I in the wall 3b of the injection nozzle 3, and only as an example of many possible exemplary embodiments.

The wall 3b is an integral part of the injection nozzle 3 located inside the combustion chamber 1. The wall 3b may be constructed, for example, cylindrical 30 or conical, with Fig. 1d showing from the outside the development of the wall 3b. The reference line 5 defines the zero point of the angle and passes through the outlet 7a. The outlet openings 7b, 7c, 7h-7I are each spaced at 10 degrees, so that angle a increases clockwise. The outlet openings 7d, 7e, 7f, 7g are also spaced 10 degrees apart, with the angle a increasing to 35 counterclockwise. In Figure 1b, the outlet direction 5a corresponds to the outlet 7a through which the reference line 5 passes. Outlets 7b and 7c correspond to directions 5b, 5c of outlet β 106885 and have a clockwise angle α1 or α2 relative to reference line 5. The outlet openings 7d, 7e, 7f correspond to the exit directions 5d, 5e, 5f and have angles a3, a4 and a5 anticlockwise with respect to the reference line 5. The shape and direction of the jet-shaped formations 6a, 6b, 6c, 6d can be influenced, e.g. Thus, a number of embodiments of the injection nozzle 3 are formed, all of which have the effect of the invention.

In a preferred embodiment, the counter-clockwise penetration openings 7d, 7e, 7f, 7g or their outlet direction 5d, 5e, 5f have an angle of at least 20 ° with respect to the reference line 5. In another preferred embodiment, the penetration openings 7d, 7e, 7f, 7g are at an angle of at least 20 ° to at most 100 ° with respect to the reference line. In another preferred embodiment, the passageways 7d, 7e, 7f, 7g are formed such that at least 15% of the amount of fuel exiting the injector nozzle 3 is injected through these opposed passageways 7d, 7e, 7f, 7f, 7f.

Figure 2 shows the relationship between the amount of fuel injected upstream of the vortex flow 4 and the NOx production or efficiency η. As the amount of fuel increases and is injected in the opposite direction to the vortex flow 4, the formation of NOx during combustion is reduced. Thus, for example, when spraying 30% of the fuel in the opposite direction, the reduction in NOx formation results in a significant change in ANOx, whereas the efficiency η decreases only by a small amount Δη.

It may be advantageous that in the upstream direction with respect to the vortex flow 4, the output fuel is controlled by a controllable means whereby the output fuel is controllable or adjustable by a sensor, e.g., a sensor for NOx and a control device. This type of controllable means may be fitted, e.g., to the injection nozzle 30 itself, e.g. as a slide, which partially obscures the passageways 7d, 7e, 7f, 7g, and is connected to a mechanical actuator. The controlled means may also be configured as a mechanical actuator that changes the position or arrangement of the fuel injector, e.g. by rotating the injectors so that the proportion of fuel directed in the upstream direction of the vortex flow 4 35 is changed.

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Claims (8)

A method for injecting fuel into a cylinder (1) of a diesel-engine type piston combustion engine (2), wherein all the specified amount of fuel at one stroke is injected into the injection nozzles (3), and the combustion air is introduced into the cylinder (2) wherein at least one fuel jet (6b, 6c) exiting the injection nozzle (3) is injected downstream with respect to the vortex flow (4), and at least one fuel jet (6d) exiting the injection nozzle (3) is injected in the opposite direction with respect to and spraying the upstream fuel jet (6b, 6c, 6d) over the same period of time and so that the flue gas from the upstream combustible fuel jet (6d) penetrates the forward fuel jet (6b, 6c). Method according to claim 1, characterized in that it defines a reference line (5) passing through the center line (2a) of the cylinder (2) and through the center line (3a) of the injection nozzle (3), and at least one fuel jet (6d) is injected at an angle of at least 20 ° between the fuel jet inlet direction (5d, 5e, 5f) and the reference line (5). Method according to Claim 1 or 2, characterized in that at least 10% of the amount of fuel exiting the injection nozzle (3) is injected in at least one upstream fuel jet (6d) relative to the vortex flow (4). Method according to one of Claims 1 to 3, characterized in that the fuel amount of the fuel jet (6d) directed in the opposite direction to the vortex flow (4) is controlled by the control means. Arrangement of the injection nozzle (3) having outlet openings (12; 7a -: · 7I) in the combustion chamber (1) of a diesel-engine type piston combustion engine, in which the combustion air is introduced into the cylinder such that a turbulent flow of combustion air is generated is arranged such that at least a first outlet (12; 7b, 7c, 7h - 7I) 35 is sprayed with a fuel jet (6b, 6c) downstream of the vortex flow (4) and at least a second outlet (12; 7d, 7e, 7f, 7g) ) through the jet • 1 '106885 δ the fuel jet (6d) in the opposite direction to the vortex flow (4), characterized in that the outlet openings (12; 7a-7I) are arranged and oriented so that the first and second outlet openings are open during the same time period, and that the flue gas 5 of the upstream outgoing combustible fuel jet (6d) penetrates downstream through the outgoing fuel jet. Arrangement according to Claim 5, characterized in that the outlets (12; 7a to 7I) of the injection nozzle (3) are formed such that at least 10% of the amount of fuel comes out through the other outlets (12; 7d, 7e, 7f) from which the fuel jet is sprayed. in the opposite direction to the vortex flow (4). Arrangement according to Claim 5 or 6, characterized in that the angle (a3, a4, a5) whose second outlets (7d, 7e, 7f) from which the fuel jet is sprayed in the opposite direction to the vortex flow (4) forms a reference line (5), extending radially from the center line (3a) of the injection nozzle (3) and perpendicular to the vortex flow (4) is in the range of 20 ° to 100 °. 7 106885 Arrangement according to one of Claims 5 to 7, characterized in that it comprises a control means which acts on the fuel amount of at least one fuel jet (6d) directed against at least one countercurrent vortex flow (4). »· ', · I m 106885 9