Search

DE-102024132881-A1 - Fuel gas injection device for supplying fuel gas to a cylinder arrangement of a reciprocating internal combustion engine, reciprocating internal combustion engine and method for operating a reciprocating internal combustion engine

DE102024132881A1DE 102024132881 A1DE102024132881 A1DE 102024132881A1DE-102024132881-A1

Abstract

The invention relates to a fuel gas injection device (10) for supplying fuel gas to a cylinder arrangement of a reciprocating internal combustion engine (200), the fuel gas injection device (10) comprising: a gas distributor (12) with a housing (16) that defines a fuel gas flow chamber (18), wherein the housing (16) has at least one fuel gas inlet (20) fluidically connected to the fuel gas flow chamber (18) and at least one fuel gas outlet (22) fluidically connected to the fuel gas flow chamber (18); and a gas flow regulator (14) configured to adjust a fuel gas flow entering the fuel gas flow chamber through the fuel gas inlet, wherein the gas distributor has a control shaft (32) rotatably mounted in the housing (16), and wherein the fuel gas inlet (20) can be fluidically connected to the fuel gas outlet (22) by rotating the control shaft. The invention also relates to a reciprocating internal combustion engine and a method for operating a reciprocating internal combustion engine.

Inventors

  • Karsten Wittek

Assignees

  • Hochschule Heilbronn, Körperschaft des öffentlichen Rechts

Dates

Publication Date
20260513
Application Date
20241111

Claims (20)

  1. Fuel gas injection device (10) for supplying fuel gas to a cylinder arrangement of a reciprocating internal combustion engine (200), the fuel gas injection device (10) comprising: - a gas distributor (12) with a housing (16) that defines a fuel gas flow chamber (18), wherein the housing (16) has at least one fuel gas inlet (20) fluidically connected to the fuel gas flow chamber (18) and at least one fuel gas outlet (22) fluidically connected to the fuel gas flow chamber (18); and - a gas flow regulator (14) comprising at least one gas valve (78) and configured to adjust the fuel gas flow entering the fuel gas flow chamber (18) through the fuel gas inlet (20), in which the gas distributor (12) has a control shaft (32) rotatably mounted in the housing (16) and coupled to a crankshaft of the reciprocating internal combustion engine (200), and in which the fuel gas inlet (20) can be fluidically connected to the fuel gas outlet (22) by rotating the control shaft (32) such that the fuel gas inlet (20) is fluidically connected to the fuel gas outlet (22) only within a limited rotational angular interval.
  2. Fuel gas injection device (10) according to Claim 1 , characterized in that the housing (16) has at least two fuel gas outlets (22) fluidically connected to the fuel gas flow space (18), wherein in a first rotation angle interval the fuel gas inlet (20) is fluidically connected to a first fuel gas outlet (22) of the fuel gas outlets (22) and in a second rotation angle interval the fuel gas inlet (20) is fluidically connected to a second fuel gas outlet (22) of the fuel gas outlets (22).
  3. Fuel gas injection device (10) according to one of the preceding claims, characterized in that the gas distributor (12) has at least one actuating element (34) with at least one fluid passage (36), wherein the actuating element (34) is rotatably arranged in the fuel gas flow chamber (18) and is connected to the control shaft (32) in such a way that the actuating element (34) is rotatable through the control shaft (32), wherein in the limited rotation angle interval the fuel gas inlet (20) is fluidically connected through the fluid passage (36) to the fuel gas outlet (22).
  4. Fuel gas injection device (10) according to the preceding claim, characterized in that the actuating element (34) is designed as an actuating plate (35).
  5. Fuel gas injection device (10) according to one of the Claims 3 and 4 , characterized in that the gas distributor (12) has a further actuating element (34A) with a fluid passage (36), wherein the further actuating element (34A) is rotatably arranged in the fuel gas flow chamber (18) and is connected to the control shaft (32) in such a way that the further actuating element (34A) is rotatable through the control shaft (32), wherein at least one fuel gas outlet (22), in particular a first group of fuel gas outlets (22), is fluidically connectable to the fuel gas inlet (20) through the fluid passage (36) of the actuating element (34), and wherein at least one other fuel gas outlet (22), in particular a second group of fuel gas outlets (22), is fluidically connectable to the fuel gas inlet (20) through the fluid passage (36) of the further actuating element (36A).
  6. Fuel gas injection device (10) according to one of the Claims 3 until 5 , characterized in that an end face (40) of the actuating element (34) is in surface contact with a contact surface of an outlet part (26) of the housing (16) having the fuel gas outlet (22).
  7. Fuel gas injection device (10) according to one of the Claims 3 until 5 , characterized in that the gas distributor (12) has a housing-fixed intermediate part (42) which is arranged between the actuating element (34) and an outlet part (26) of the housing (16) having the fuel gas outlet (22), wherein the intermediate part (42) has a fluid channel (44) fluidically connected to the fuel gas outlet (22), and wherein an end face (40) of the actuating element (34) is in surface contact with a contact surface (46) of the intermediate part (42).
  8. Fuel gas injection device (10) according to one of the Claims 6 and 7 , characterized in that the actuating element (12) is made of graphite at least in the area of the end face (40), and/or that the exit part (26) or the intermediate part (42) is made of graphite at least in the area of the contact surface.
  9. Fuel gas injection device (10) according to one of the Claims 3 until 8 , characterized in that the fluid passage (36) is limited by a control edge (50) forward in the direction of rotation (48) and a control edge (52) rearward in the direction of rotation (48).
  10. Fuel gas injection device (10) according to one of the Claims 7 until 9 , that the shape and size of the fluid channel (44) corresponds to the shape and size of the fluid passage (36).
  11. Fuel gas injection device (10) according to one of the Claims 3 until 10 , thereby known The figure shows that the gas distributor (12) has a spring unit (58) which applies a spring force to the actuating element (34) by which the actuating element (34) is forced in the direction of the fuel gas outlet (22), in particular against the contact surface of the outlet part (26) or against the contact surface (46) of the intermediate part (42).
  12. Fuel gas injection device (10) according to one of the Claims 1 and 2 , characterized in that an exhaust valve (104) is associated with the fuel gas outlet (22), wherein the exhaust valve (104) can be actuated by a rotation of the control shaft (32).
  13. Fuel gas injection device (10) according to the preceding claim, characterized in that the control shaft (32) is designed as a camshaft.
  14. Fuel gas injection device (10) according to one of the preceding claims, characterized in that a sealing unit (56) is arranged on the control shaft (32), in particular wherein the sealing unit (56) has a plastic ring and an O-ring which is arranged radially inside the plastic ring and exerts a radially outwardly acting contact force on the plastic ring.
  15. Fuel gas injection device (10) according to the preceding claim, characterized in that a sealing bushing (54) is pressed into the housing (16), wherein the control shaft (32) extends through the sealing bushing (54) into the fuel gas flow chamber (18), and wherein the sealing bushing (54) forms a running surface for the sealing unit (56).
  16. Fuel gas injection device (10) according to one of the preceding claims, characterized in that the fuel gas injection device (10) has a drive shaft (60) which is mechanically coupled to the control shaft (32) by a gear unit, wherein the control shaft (32) can be coupled to the crankshaft by the drive shaft (60).
  17. Fuel gas injection device (10) according to the preceding claim, characterized in that the drive shaft (60) has a conical seat surface (64) for connecting the drive shaft (60) to a drive gear.
  18. Fuel gas injection device (10) according to one of the preceding claims, characterized in that an outlet line (80) is connected to the fuel gas outlet (22).
  19. Fuel gas injection device (10) according to one of the preceding claims, characterized in that the gas flow controller (14) has at least two gas valves (78) which are connected in parallel to each other.
  20. A reciprocating internal combustion engine (200) comprising: - a cylinder arrangement comprising at least one cylinder unit (204), wherein the cylinder unit (204) has a combustion chamber (206) in which a piston (208) is slidably mounted; - a crankshaft; and - a fuel gas injection device (10) according to any one of the preceding claims, wherein the control shaft (32) of the fuel gas injection device (10) is coupled to the crankshaft, and wherein fuel gas can be supplied to the combustion chamber (206) of the cylinder unit (204) through the fuel gas outlet (22).

Description

The invention relates to a fuel gas injection device for supplying fuel gas to a cylinder assembly of a reciprocating internal combustion engine. The invention also relates to a reciprocating internal combustion engine with such a fuel gas injection device and a method for operating such a reciprocating internal combustion engine. The fuel gas injection device described herein is applicable to reciprocating internal combustion engines (hereinafter also referred to as "reciprocating engines" for the sake of simplicity) that are operated with a gaseous fuel (fuel gas). The application primarily aims at the use of hydrogen ( H₂ ) as the fuel gas. However, other fuel gases can also be used, for example, methane ( CH₄ ), ammonia ( NH₃ ), or gas mixtures. Fuel gas injection systems for reciprocating engines are state of the art. According to one classification method, fuel gas injection systems can be divided into three groups based on the location where the fuel gas and combustion air are combined (location of mixture formation). In the first group of fuel gas injection systems, a fuel gas flow is metered into the total airflow upstream of a turbocharger at a single point, i.e., centrally. This type of metering is also referred to as central mixture formation. In the second group of fuel gas injection systems, fuel gas is introduced into at least one intake port of each cylinder unit. Preferably, the fuel gas is introduced into the intake port near the intake valves to minimize the amount of combustible mixture present upstream. This type of metering is also referred to as port fuel injection or intake manifold injection. Another common term is PFI injection (from the English PFI = port fuel injection). In the third group of fuel gas injection systems, fuel gas is introduced directly into the combustion chamber of the cylinder units. Here, the fuel gas injection preferably occurs intermittently via a so-called DI injector (from the English DI = direct injection). In most stationary gas engines powered by natural gas, the fuel-air mixture is formed using a centralized mixing system. This usually involves the continuous metering of fuel gas via a Venturi mixer. When hydrogen or a fuel gas mixture with a high hydrogen content is used as the fuel, centralized mixture formation is less suitable. With centralized mixture formation, a large quantity of combustible gas mixture is permanently present upstream of the intake valves. In the event of backfire, this large quantity of gas mixture is set into reaction. Consequently, a pressure and temperature increase occurs in the charge air system, which can lead to damage to components. A second classification method allows fuel gas injection devices to be divided into two groups according to the type of fuel gas injection. In continuous injection, a fuel gas stream is injected continuously, i.e., without interruptions, into an air stream. A continuous fuel gas stream is frequently used in connection with direct mixture formation. Intake manifold injection systems can be equipped with continuous injection. However, this type of fuel gas supply is less suitable when using hydrogen as the fuel gas. Due to the continuous flow of fuel gas into the intake manifold, there is a constant presence of combustible gas upstream of the intake valves. When the intake valve opens, the combustible gas mixes with hot residual gas in the combustion chamber. This can result in an undesirable backfire. In intermittent injection, a fuel gas stream is injected intermittently, i.e., with interruptions, into an air stream. Intermittent injection is used in most duct injection systems and all direct injection systems. Most intermittent fuel gas injection systems utilize intermittently operating injectors. Intermittently operating injectors are state of the art. Intermittently operating injectors usually have a movable valve element, which is preferably pressed against a housing-side seat by means of a closing spring. If the injector is to open an inflow cross-section, an opening force must be applied that opposes the spring force of the closing spring. In most injectors, this opening force is generated by means of an electromagnet. This type of injector actuation is called electromagnetic direct actuation. It enables short opening and closing times as well as high precision, i.e., low stroke profile deviations. From the DE 10 2020 127 020 B3 The applicant is aware of a pneumatically actuated DI injector in which the pressurized fuel gas is used as the working fluid to open a valve. The in the DE 10 2020 127 020 B3 The described injector can also be used as a PFI injector, i.e., for injecting fuel gas into an intake port of a cylinder unit. For large-volume engine cylinders, a correspondingly large inlet cross-sectional area must be provided to ensure sufficient fuel gas can be metered in within the available time. This applies equally to port injection (PFI) and direct injection (DI). In large-displ