Pre-chamber injection device

Abstract

FIELD: internal combustion engines.SUBSTANCE: pre-chamber injection device comprises a housing (1) with a central cavity (2) with an installation thread (3) for a spark plug. There is a pre-chamber (5) with injection holes (6) for supplying fuel gas, communicating with the nozzle tip (7). In the wall of the housing (1) there are longitudinal gas supply channels (8) to the injection holes (6), communicating through a distribution channel (9) made in the upper part of the housing (1) with a branch pipe (10) for supplying fuel gas. The pre-chamber injection device is made as a monolithic one-piece structure from a refractory and durable material using additive technologies. The device comprises a closed independent cooling system for the pre-chamber injection device. The closed independent cooling system consists of a pipe (13) for supplying coolant to the pre-chamber injection device, an annular channel for cooling the pre-chamber, a channel (12) for supplying coolant to the annular channel (15) for cooling the pre-chamber, a channel (16) for removing coolant from the annular channel (15) for cooling the pre-chamber, and a pipe (17) for removing coolant from the pre-chamber injection device.EFFECT: reduced temperature of the device.3 cl, 3 dwg

Description

[0001] The invention relates to the field of mechanical engineering, namely to fuel supply systems for internal combustion engines (ICE) with a pre-chamber device for igniting the fuel-air mixture, and can be used in internal combustion engines with pre-chamber ignition for operation on a lean gas-air mixture.

[0002] A remote pre-chamber radiator (patent RU 497 U1, published June 16, 1995, IPC F02B 19 / 12) is known. It comprises a casing filled with a heat-conducting agent. The pre-chamber body in the spark plug contact area is protected by a copper casing, and the heat-conducting agent is made of low-melting metals or their alloys. This device does not provide the required cooling efficiency due to the practical limitations of the sealing plates that transfer heat to the atmosphere, and accordingly, their heat-transfer capacity is limited by their geometric dimensions.Moreover, the thermal energy absorbed by the low-melting metal during the phase transition is limited by the total heat capacity of this low-melting metal. This means that energy removal from the pre-chamber due to melting of the metal will only occur during the phase transition, until thermodynamic equilibrium between the low-melting metal and the pre-chamber is reached. Consequently, the temperature will continue to rise. Energy transfer through the threaded connection between the pre-chamber body and the engine combustion chamber body is insufficiently effective for cooling the pre-chamber and spark plug, as has been demonstrated by numerous experiments with various pre-chamber designs. This device, due to the combination of measures employed, is not capable of ensuring the long-term operation of a pre-chamber piston internal combustion engine, as overheating of the spark plug and pre-chamber is inevitable.

[0003] A prechamber device for an internal combustion engine is known (US Patent 11035288 B2, published January 15, 2021, IPC F02B 19 / 12), which comprises a prechamber body with coolant passages formed therein, forming part of the engine cylinder head cooling jacket. In this device, cooling is implemented as part of the overall piston engine cylinder head cooling system, which requires the use of a suitable piston engine cylinder head, thus limiting the device's applicability. The applied solution requires a reliable seal between the prechamber body and the piston engine cylinder head, as this carries the risk of coolant ingress into the combustion chamber. Over time, as the prechamber is used and the seal wears, this solution will inevitably lead to failure of the piston internal combustion engine.

[0004] A pre-chamber injection device is known (patent RU 2818109 C1, published on 24.04.2024, IPC F02B 19 / 12, F02B 19 / 16, F02B 19 / 18), which comprises a housing having a central cavity with an installation thread for a spark plug and a pre-chamber with injection holes for supplying fuel gas, communicating with a nozzle tip. In the wall of the housing, longitudinal gas supply channels with injection holes are made, communicating through an annular distribution channel made in the upper part of the housing with the supply channel of the fuel gas supply pipe, made with a connecting thread for connection to the fuel supply line. The pre-chamber injection device is made in the form of a monolithic one-piece structure from a refractory and durable material using additive technologies. This pre-chamber injection device is the closest in design to the declared device and is presented as a prototype.

[0005] The described pre-chamber injection device has a drawback: during operation, the pre-chamber injection device heats up, which reduces the device's reliability and limits its ability to operate within the internal combustion engine's power range. When the engine power exceeds 5 kW per cylinder, the pre-chamber injection device near the spark plug electrode heats up to a temperature above 900°C, which causes rapid spark plug wear.

[0006] The technical objectives of the invention are to create a pre-chamber injection device with a closed and independent cooling system, to reduce the temperature of the pre-chamber injection device to an operating temperature not exceeding the operating temperature of a piston internal combustion engine, to stabilize the temperature of the spark plug near the electrode to 400-500°C without the effect of pre-ignition and erosion of the spark plug, as well as to expand the possibility of using the present invention over the power range of piston internal combustion engines, and to increase the reliability of the device.

[0007] The stated problem is solved by the following design of the pre-chamber injection device.

[0008] According to the invention, a pre-chamber injection device comprises a housing with a central cavity with a mounting thread for a spark plug, a pre-chamber with injection holes for supplying fuel gas, communicating with a nozzle tip. Longitudinal gas supply channels to the injection holes are located in the wall of the housing. The gas supply channels communicate through a distribution channel formed in the upper part of the housing, which communicates with a fuel gas supply pipe. A coolant supply pipe is located in the wall of the housing, communicating with a coolant supply channel to an annular cooling channel of the pre-chamber, which communicates with a coolant discharge channel, which communicates with the coolant discharge pipe. The coolant supply channel is located longitudinally to the housing from the supply pipe to the annular cooling channel of the pre-chamber.The coolant return channel is completely symmetrical to the coolant supply channel and is located longitudinally along the housing, from the annular prechamber cooling channel to the coolant return pipe. This water-cooled prechamber injection device solution ensures a stable spark plug operating temperature by cooling the device housing and the spark plug mounting threads. It does not share any channels with the cylinder head, creating a closed, independent cooling system.

[0009] The applied technical solution stabilizes the temperature of the device, reducing it to the operating temperature of the spark plug, which does not exceed the operating temperature of the piston internal combustion engine, throughout the entire power range of known piston internal combustion engines, and also increases the reliability of the device.

[0010] The annular cooling channel of the pre-chamber has a cross-section of an irregular rhombus.

[0011] The coolant inlet pipe and the coolant outlet pipe are provided with connecting threads for coolant pipes.

[0012] The device is equipped with mounting lugs for mounting the device on the cylinder head of a piston internal combustion engine.

[0013] The housing with the pre-chamber, longitudinal gas supply channels, distribution channel, fuel gas supply pipe, nozzle tip, coolant supply pipe, coolant supply channel, annular pre-chamber cooling channel, coolant discharge channel and coolant discharge pipe made in it are made in the form of a monolithic one-piece structure from a refractory and durable material using additive technologies.

[0014] The claimed technical solution is explained by drawings in the form of volumetric geometric models of the pre-chamber injection device, which depict:

[0015] - in Fig. 1 - a longitudinal section of the pre-chamber injection device;

[0016] - in Fig. 2 - a cross-section according to Fig. 1 between the distribution channel and the installation thread for the spark plug, in the area of ​​the middle part of the device, a bottom view, explaining the location of the gas supply channels, the coolant supply channel and the coolant discharge channel in the wall of the device housing;

[0017] - Fig. 3 - general view of the pre-chamber injection device.

[0018] The pre-chamber injection device (Fig. 1) comprises a housing 1 having a central cavity 2 with an installation thread 3 for a spark plug 4 and a pre-chamber 5 with injection holes 6 for supplying fuel gas, communicating with a nozzle tip 7.

[0019] In the wall of the housing 1, longitudinal gas supply channels 8 (Fig. 2) are made up to the injection holes 6, communicating through a distribution channel 9 made in the upper part of the housing 1, communicating with the fuel gas supply pipe 10 with a connecting thread 11 (Fig. 3).

[0020] A longitudinal coolant supply channel 12 is formed in the wall of the housing 1, into which coolant enters through a coolant supply pipe 13, made with a connecting thread 14 (Fig. 3) for a coolant pipeline (not shown in the image). The coolant supply channel 12 (Fig. 1) communicates with an annular cooling channel of the pre-chamber 15. A coolant discharge channel 16 is formed longitudinally in the wall of the housing 1, which communicates with its lower part with the annular cooling channel of the pre-chamber 15 and communicates with a coolant discharge pipe 17, made with a connecting thread 18 (Fig. 3) for a coolant pipeline (not shown in the image).

[0021] The annular cooling channel of the pre-chamber 15 is adapted to the modern production capabilities of additive technologies and has a cross-section of an irregular rhombus.

[0022] In the upper part of the housing 1, mounting lugs 19 are made for fastening the device to the cylinder head of a piston internal combustion engine.

[0023] The pre-chamber injection device is made in the form of a monolithic one-piece structure made of refractory material, manufactured using additive technologies, such as 3D metal printing using the selective laser sintering method from spherical powder of Inconel 718 nickel alloy.

[0024] The device operates by supplying gas fuel directly to the cylinder of a piston engine, as well as initiating the combustion process in an internal combustion engine by igniting the fuel-air mixture inside the pre-chamber 5 of the pre-chamber injection device.

[0025] Fuel gas from the fuel supply pipeline through a valve (not shown) enters through the fuel gas supply pipe 10 and is then distributed in the distribution channel 9 through the gas supply channels 8 with excess pressure to the injection holes for supplying fuel gas 6, through which in turn it enters the pre-chamber 5.

[0026] When the fuel-air mixture is ignited by spark plug 4, a flare ignition occurs in pre-combustion chamber 5, effectively igniting the lean fuel-air mixture within the cylinder of a piston internal combustion engine. This causes the pre-combustion chamber injection device to heat up.

[0027] Water cooling of the pre-chamber injection device is implemented as follows. The coolant supplied through the coolant supply pipe 13 through the coolant supply channel 12 into the annular cooling channel of the pre-chamber 15, then enters through the coolant discharge channel 16 into the coolant discharge pipe 17, provides the operating temperature of the spark plug 4, stabilizing it near the electrode to 400-500 ° C without the effect of pre-ignition and erosion of the spark plug, cooling the body 1 of the device and the installation thread 3 of the spark plug 4. The coolant flowing through the annular cooling channel of the pre-chamber 15 reduces the temperature of the pre-chamber 5, increasing the reliability of the device.

[0028] These solutions allow for more efficient combustion of the lean fuel-air mixture in the combustion chamber of a piston internal combustion engine over a wide range of loads.

[0029] The proposed device has increased reliability, which is achieved by the measures taken to maintain the operating temperatures of the device.

[0030] The proposed pre-chamber injection device can be adapted to various piston internal combustion engines.

[0031] Through engineering calculations, experimental research and testing, the achievement of the technical result was confirmed.

Claims

1. A pre-chamber injection device comprising a housing with a central cavity with an installation thread for a spark plug, a pre-chamber with injection holes for supplying fuel gas, communicating with a nozzle tip, longitudinal gas supply channels located in the wall of the housing to the injection holes, communicating through a distribution channel made in the upper part of the housing with a fuel gas supply pipe, wherein the pre-chamber injection device is made in the form of a monolithic one-piece structure from a refractory and durable material using additive technologies, characterized in that it contains a pipe for supplying coolant to the pre-chamber injection device, an annular cooling channel for the pre-chamber, a channel for supplying coolant to the annular cooling channel of the pre-chamber, a channel for removing coolant from the annular cooling channel of the pre-chamber, a pipe for removing coolant from the pre-chamber injection device,forming a closed independent cooling system of the pre-chamber injection device, 2. The device according to paragraph 1, characterized in that the coolant supply pipe and the coolant outlet pipe are made with a connecting thread for the coolant pipeline.

3. The device according to paragraph 1, characterized in that the annular cooling channel of the pre-chamber has a cross-section of an irregular rhombus.

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