Injection nozzle and device for loading a fuel with gas

Abstract

Injection nozzle (1,5) for fuel, preferably diesel fuel, wherein a diffusion device (2,6) is directly or indirectly connected to the nozzle, characterized in that gas is supplied to the fuel by diffusion.

Description

[0001] The invention relates to an injection nozzle and an apparatus / device directly or indirectly connected to it for loading the fuel by diffusion / permeation with gas, hereinafter referred to as a diffusion device, for example air or air and exhaust gas. State of the art

[0002] Patent DE 314 252 A describes an open nozzle in which the fuel is conveyed by air through a storage chamber and cutting area into the cylinder chamber. The air is used to discharge the fuel.

[0003] Furthermore, US Patent 5,150,836 A discloses an open injection nozzle in which fuel is delivered to the engine by means of a pulse using a precisely controlled amount of gas. The pressure and gas volume are sufficient to propel the fuel from the nozzle at nearly the speed of sound.

[0004] GB 1 459 097 A lists a gas atomizing nozzle in which the liquid and gas are combined via spiral channels at a focal point.

[0005] DE 10 2015 216 727 A1 discloses the use of a two-component nozzle for injecting a fuel-water emulsion into an internal combustion engine, wherein the mixing of the two components takes place inside or outside the nozzle. DE 198 15 042 A1 also discloses that, particularly for operating a starting aid system for engines that run primarily on vegetable oils, diesel fuel is vaporized via an evaporator tube containing a glow plug and mixed with intake air. The diesel operation is intended to continue only until the engine reaches operating temperature.

[0006] DE 197 13 377 A1 describes a nozzle in which a fluid, in particular fuel, is guided through channels in such a way that a swirling fluid flow is created which enters a second fluid, in particular combustion air and thereby leads to a fine distribution of the fuel.

[0007] The aforementioned devices and methods have in common that either air is used to discharge the fuel or diesel fuel is atomized by collision of the fluids.

[0008] In DE 10 2013 213 349 B4, an internal combustion engine is described which is operated in a first operating state with different liquid fuels (diesel, etc.) and in a second operating state with gas.

[0009] DE 11 2006 000 809 T5 describes an injector having openings in two planes, whereby the fuel is expelled through these openings and thereby mixes.

[0010] EP 3 058 208 A1 claims a liquid injector for generating atomized liquid, wherein the pressurized liquid and the gas are directed to adjacent focal points and collide.

[0011] In the aforementioned patent applications, fuel and gas are managed in different ways so that they interact with each other, thereby improving fuel distribution. Furthermore, it is known (DE 601 10 544 T2, DE 10 2007 017 561 A1 and DE 20 2012 100 107 U1) to operate an internal combustion engine (diesel engine) in mixed operation with gaseous fuel and diesel fuel in such a way that both energy sources are used in a mixture. This combines the positive properties of homogeneous combustion of gaseous fuel with the inhomogeneous combustion of diesel fuel.

[0012] From DE 10 2018 219 935 A1, it is known to supply liquid cryogenic fuel to the combustion engine via the intake manifold or the pre-chamber using at least one injector. In an extension, liquid and gaseous fuel can also be supplied to the engine simultaneously or sequentially.

[0013] EP 1 647 685 A2 is also known as an internal combustion engine that operates with two types of fuel, whereby at least one first type of fuel is supplied, then a second type of fuel is supplied by switching, and a fuel mixture ratio is set depending on the volume of fuel supplied.

[0014] The specific formulation of the application of diesel and gasoline is also known (DE 10 2012 112 337 A1), whereby gasoline is first loaded in the conventional manner and diesel fuel is injected after compression. These systems require two fuels to produce combustion with the desired properties. In all these designs, the costs are considerable, and two fuels must always be carried.

[0015] The production of perforated and non-perforated polymeric structures of varying porosity and from different materials using phase separation technology is described in WO 02 / 043 937 A2. This method can also be used to manufacture atomizing nozzles for fuel injection. Diffusion in the classical sense does not occur. Objective of the invention

[0016] The aim of the invention is to homogenize the fuel distribution and distribution density in the diesel process and thereby influence the combustion process in such a way that unburned fuel is minimized and less soot is produced. This simultaneously improves the conversion of fuel into mechanical energy. Inventive solution

[0017] The invention comprises an injection nozzle and a diffusion device directly or indirectly connected to it for loading the fuel, typically diesel fuel, with gas, for example, air or exhaust gas, or even air and exhaust gas. The fuel is loaded with gas in the diffusion device via a semipermeable membrane (gas filter), preferably a sintered metal gas filter or a ceramic filter. The semipermeable membrane has a pore size that allows the gas to pass through while retaining the fuel when at rest. During operation, the gas is subjected to a higher pressure than the fuel pressure.

[0018] The flow resistance of the semipermeable membrane depends on the pore size and pore length. The aforementioned fuels and gases exhibit almost purely viscous behavior. Therefore, the viscosity ratio is the determining factor for the flow through the respective components. Under the same pressure conditions, the viscosity ratio of, for example, diesel to air under normal conditions is greater than 10. 4 Under these conditions, no diesel will flow through the semipermeable membrane.

[0019] Since the viscosity ratio of diesel fuel to air is very high, air / gas can be added to the diesel fuel via diffusion through the semipermeable membrane.

[0020] The parameters permeation area and thickness, gas pressure and fuel pressure are designed so that the required amount of gas is absorbed by the fuel through diffusion.

[0021] After the injection of the loaded fuel, the dissolved gas causes the droplets exiting the injection nozzle to spontaneously burst due to the gas pressure within the droplets after the pressure is released in the compression chamber, resulting in a very fine and even distribution of the fuel.

[0022] The subsequent combustion process results in a homogeneous temperature distribution, thus minimizing soot production. Furthermore, this homogeneous combustion reduces excess air during combustion and, through exhaust gas recirculation, the formation of NOₓ. x will be reduced.

[0023] The diffusion of the gas into the fuel is a surface and time process; therefore, the surface-to-volume ratio of the fuel is made as large as possible as it flows through the diffusion device.

[0024] The required gas pressure is determined by the pressure drop for gas passage through the semipermeable membrane (viscous pressure drop) and the required and specified pressure for gas diffusion (diffusion pressure gradient). The saturation volume for gas is proportional to the diffusion pressure over a wide range (Dalton's law). The overpressure relative to the injection pressure is selected according to the gas requirements in the fuel. Example of implementation

[0025] The invention is described in more detail below with reference to exemplary embodiments and the associated drawings relating to these exemplary embodiments. Fig. Figure 1 shows a schematic representation of the injection nozzle with directly connected diffusion unit. Fig. Figure 2 also shows a schematic representation of the injection nozzle with indirect connection of the diffusion unit. Fig. Figure 3 shows a schematic representation of the section through the diffusion device during diffusion of the gas into the fuel from one side. Fig. Figure 4 shows a section through an area of ​​the diffusion device with gas being fed into the fuel from two sides.

[0026] As from Fig. As can be seen in Figure 1, the injector nozzle 1 is directly connected to the diffusion device 2; they form a single unit. The supply line 3 delivers the gas at the required pressure, and line 4 carries the fuel to the injector nozzle 1 via the diffusion device 2. An advantage of this arrangement is that the gas content of the fuel can be dynamically adjusted to meet specific requirements.

[0027] Fig. Figure 2 shows the injector nozzle 5, which is connected to the diffusion device 6 via a line 9. The supply lines 7 and 8 on the diffusion device 6 provide the gas and the fuel. Line 9 delivers the gas-enriched fuel to the nozzle. An advantage of this arrangement is that a larger quantity of the gas-enriched fuel is contained in line 9, thus ensuring a stable supply to the nozzle even under dynamic fuel demand.

[0028] The supply of fuel to the nozzle by a diffusion device, in which gas is supplied by diffusion, can also be carried out in such a way that more than one diffusion device is used. Fig. 1 and Fig. 2 not shown, supply the nozzle with gas-enriched fuel and in the same way a diffusion device can supply several nozzles with the gas-enriched fuel.

[0029] In Fig. Figure 3 schematically shows the cutaway diffusion device 10. Gas is introduced into this device in region 12. The tubular geometry 11 represents the semipermeable membrane (microporous membrane). The outer tubular geometry 14 is arranged around this tube, with the fuel flowing in the space 13 between the outer wall 14 and the outer geometry of the semipermeable membrane 11.

[0030] The semipermeable membrane 11, in this example made of sintered stainless steel (CrNi steel), has a porosity that, depending on its dimensions and operating conditions, allows the necessary gas components to pass through while preventing the fuel, preferably diesel fuel, from diffusing through the semipermeable membrane. This is prevented by the higher gas pressure compared to the fuel pressure and the significantly higher viscosity of the fuel compared to the diffusing gases such as air or exhaust gas.

[0031] To increase diffusion into the fuel, it is also possible, as in Fig. As shown in Figure 4, the gas supply to the fuel in area 18 takes place via the semipermeable membranes 17 and 19. The provision of the gas for diffusion is achieved by areas 16 and 20.

[0032] To achieve the most favorable surface area to volume ratio of the fuel for diffusion, the thickness of the flowing fuel is kept small, which increases the pressure drop of the flow. However, the flow velocity in the diffusion device is relatively low, so the flow pressure drops are small. To further optimize diffusion, the semipermeable membrane can also be designed such that, through a chosen topography, for example, with the same radius, the surface area is increased. This is achieved by corrugating, interlocking, or otherwise shaping the surface to increase the surface area.

[0033] The design of the diffusion device is not limited to tubular geometries; rather, other cross-sections, such as rectangular geometries or elliptical cross-sections, can also be used. List of reference symbols 1 injector 2 Diffusion device 3 Gas supply line 4 Fuel supply line 5 injector 6 Diffusion device 7 Gas supply line 8 Fuel supply line 9 Fuel line with gas 10 Diffusion device 11 semipermeable membrane 12 Gas area 13 Fuel Area 14 cylinder wall 15 cylinder wall 16 Gas area 17 semipermeable membrane 18 Fuel Area 19 semipermeable membrane 20 Gas Area

Claims

Injection nozzle (1,5) for fuel, preferably diesel fuel, wherein a diffusion device (2,6) is directly or indirectly connected to the nozzle, characterized in that gas is supplied to the fuel by diffusion. Injection nozzle according to claim 1 characterized in that the injection nozzle (1) and the diffusion device (2) form a structural unit. Injection nozzle according to claim 1 characterized in that the injection nozzle (5) and the diffusion device (6) are structurally separated. Injection nozzle according to claims 1 to 3 characterized in that gas is supplied to the fuel by diffusion via semipermeable membranes (11, 17, 19). Injection nozzle according to claim 4 characterized in that the semipermeable membrane (11,17,19) of the diffusion device (2,6) is made of sintered metal. Injection nozzle according to claim 5 characterized in that the semipermeable membrane (11,17,19) of the diffusion device (2,6) is made of CrNi steel. Injection nozzle according to claim 4 characterized in that the semipermeable membrane (11,17,19) of the diffusion device (2,6) is made of ceramic. Injection nozzle according to claims 1 to 7 characterized in that in the diffusion device (2,6) air or exhaust gas as well as air and exhaust gas (12,16,20) of different compositions are supplied to the fuel (13,18). Injection nozzle according to claims 1 to 7 characterized in that gas (12,16,20) of different composition is supplied to the fuel (13,18).

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