A multi-point injection system for a marine methanol engine intake duct

Abstract

The utility model discloses a kind of marine methanol engine air intake passage multi-point injection systems, belong to methanol engine technical field, solve the problem that methanol common rail pipe residual methanol fuel is difficult to discharge of existing multi-point injection system. It includes methanol common rail pipe, cylinder head airway, still includes electromagnetic pressure stabilizing valve, rail pressure sensor, ECU control unit;The outer tube is also provided with the new air pipe connected with air compressor on one end close to inlet flange, the new air pipe is communicated with inner tube, and electromagnetic valve is equipped on the new air pipe, the outer tube is also provided with the exhaust pipe communicated with inner tube on one end close to electromagnetic pressure stabilizing valve, the tail end of the exhaust pipe is communicated with methanol pressure relief pipe, and on-off valve is equipped on the exhaust pipe.The utility model's multi-point injection system can blow out and recycle residual methanol fuel to container, avoid the problem of resource waste, meet the requirement of intrinsically safe engine simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of engine technology, and more specifically, to a multi-point injection system for the intake manifold of a marine methanol engine. Background Technology

[0002] Currently, methanol engine injection methods are mainly divided into three types: dual-fuel injection, direct injection, and port injection. Dual-fuel injection requires two independent injection systems, resulting in a complex control system that demands precise control of the fuel ratio. Direct injection offers high thermal efficiency but places high demands on the reliability of components such as methanol nozzles and high-pressure pumps. Port injection boasts a simple structure and low cost, making it suitable for retrofitting traditional engines. Due to structural limitations of various engines, port injection systems have diverse design options, ranging from injection in the intake manifold to injection in the cylinder head. Considering the intrinsically safe requirements of marine engines and issues such as methanol wetting the walls, a multi-point injection structure using the cylinder head intake manifold is chosen, offering significant advantages over intake manifold injection.

[0003] According to ship design requirements, existing methanol engine intake multi-point injection systems typically employ a double-layered methanol common rail structure to prevent methanol fuel leakage into the hull and meet the requirements for intrinsically safe marine engines. However, during maintenance, methanol fuel residue remains in the common rail after the engine is shut down. Disassembling the line poses a risk of spillage, resulting in resource waste and safety hazards.

[0004] Therefore, there is an urgent need to design a new type of multi-point injection system for the intake of marine methanol engines to solve the above-mentioned technical problems. Utility Model Content

[0005] The technical problem to be solved by this utility model is to address the above-mentioned shortcomings of the prior art. The purpose of this utility model is to provide a multi-point injection system for the intake of a marine methanol engine, which can blow out residual methanol fuel and recover it into a container, thus avoiding the problem of resource waste, while meeting the requirements of intrinsically safe engines.

[0006] The technical solution of this utility model is as follows: A multi-point injection system for the intake manifold of a marine methanol engine includes a methanol common rail and a cylinder head intake manifold. The methanol common rail is connected to the cylinder head intake manifold through multiple methanol injection valves. It also includes an electromagnetic pressure regulator, a rail pressure sensor, and an ECU control unit. One end of the methanol common rail is provided with an inlet flange, and the other end is connected to the electromagnetic pressure regulator. The output end of the electromagnetic pressure regulator is equipped with a methanol pressure relief pipe, which is connected to a methanol collection tank. The methanol common rail includes an inner pipe and an outer pipe, with a cavity between the inner and outer pipes. Both ends of the outer pipe are fixedly connected to the inlet flange and the electromagnetic pressure regulator, respectively. The pipe is connected to an inlet flange and an electromagnetic pressure regulating valve at both ends. The rail pressure sensor is installed at the end of the outer pipe near the electromagnetic pressure regulating valve, and the probe of the rail pressure sensor extends into the inner pipe. The outer pipe is also provided with a fresh air pipe connected to an air compressor at the end near the inlet flange. The fresh air pipe is connected to the inner pipe and is equipped with a solenoid valve. The outer pipe is also provided with an exhaust pipe connected to the inner pipe at the end near the electromagnetic pressure regulating valve. The end of the exhaust pipe is connected to a methanol pressure relief pipe and is equipped with a switch valve. The methanol injection valve, electromagnetic pressure regulating valve, rail pressure sensor, solenoid valve, and switch valve are all electrically connected to the ECU control unit.

[0007] As a further improvement, the methanol common rail pipe is composed of two double-layer pipe sections connected by a connecting flange, and a first sealing gasket is provided between the corresponding connecting flanges of the two double-layer pipe sections.

[0008] Furthermore, one end of the inner tube of one of the double-layered pipes is provided with a tapered tube, which extends to the outside of the connecting flange corresponding to the double-layered pipe. Correspondingly, one end of the inner tube of the other double-layered pipe is provided with a tapered cavity adapted to the tapered tube. The tapered cavity is located inside the connecting flange corresponding to the double-layered pipe, and the tapered tube is inserted into the tapered cavity. A sealing structure is provided between the tapered tube and the tapered cavity.

[0009] Furthermore, the sealing structure includes a second sealing gasket, which is located at the bottom of the inner cavity of the conical cavity. When the connecting flanges of the two double-layer pipes are connected and tightened, the end of the conical pipe is pressed against the second sealing gasket.

[0010] Furthermore, the sealing structure also includes a sealing ring, which is fixed to the outer wall of the tapered tube. When the connecting flanges of the two double-layer tubes are connected and tightened, the outer wall of the sealing ring is pressed against the inner wall of the tapered cavity.

[0011] Furthermore, each of the two double-layer pipes has a uniformly distributed connecting rod fixed to the outer wall of the end of the inner pipe near the connecting flange, and the other end of each connecting rod is fixedly connected to the outer pipe.

[0012] Furthermore, the wall thickness of the inner tube is greater than that of the outer tube.

[0013] Beneficial effects

[0014] Compared with the prior art, the advantages of this utility model are as follows:

[0015] 1. The multi-point injection system of this utility model connects the inner pipe to the air compressor by setting a fresh air pipe on the methanol common rail pipe, and connects the inner cavity to the methanol pressure relief pipe by setting an exhaust pipe on the methanol common rail pipe. Before disassembling the pipe for maintenance, fresh air can be blown into the inner pipe to clean the methanol fuel in the inner pipe. The exhaust pipe leads to the methanol pressure relief pipe, which can blow out the residual methanol fuel and recover it into the container, avoiding the problem of resource waste, and at the same time meeting the requirements of intrinsically safe engines.

[0016] 2. The multi-point injection system of this utility model has a segmented structure for its methanol common rail, which is convenient to manufacture and facilitates the alignment of the methanol injection valve with the cylinder head air passage. Furthermore, the inner tube of the methanol common rail is installed by connecting the tapered tube and the tapered cavity, and the connection surfaces of the inner and outer tubes are staggered to avoid stress concentration at the connection flange, effectively extending the service life of the methanol common rail and further improving the sealing performance of the inner tube. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic cross-sectional view of the methanol common rail system in this utility model.

[0019] Figure 3 for Figure 2 Enlarged structural diagram at point A;

[0020] Figure 4 This is a schematic cross-sectional view of the disassembled methanol common rail pipe in this utility model.

[0021] Figure 5 for Figure 4 Enlarged schematic diagram of the structure at point B.

[0022] Wherein: 1-Methanol common rail, 2-Cylinder head intake port, 3-Methanol injection valve, 4-Solenoid pressure regulator, 5-Rail pressure sensor, 6-ECU control unit, 7-Inlet flange, 8-Methanol pressure relief pipe, 101-Inner pipe, 102-Outer pipe, 103-Clamping cavity, 104-Fresh air duct, 105-Solenoid valve, 106-Exhaust duct, 107-Switch valve, 108-Connecting flange, 109-First sealing gasket, 110-Conical pipe, 111-Conical cavity, 112-Second sealing gasket, 113-Sealing ring, 114-Connecting rod. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0024] See Figure 1-5 As shown, this utility model discloses a multi-point injection system for the intake manifold of a marine methanol engine, including a methanol common rail 1 and a cylinder head intake manifold 2. The methanol common rail 1 is connected to the cylinder head intake manifold 2 through multiple methanol injection valves 3. It also includes an electromagnetic pressure regulator 4, a rail pressure sensor 5, and an ECU control unit 6. An inlet flange 7 is provided at one end of the methanol common rail 1 for easy connection to a methanol fuel supply pipe. The other end of the methanol common rail 1 is connected to the electromagnetic pressure regulator 4, and a methanol pressure relief pipe 8 is installed at the output end of the electromagnetic pressure regulator 4. The methanol pressure relief pipe 8 is connected to a methanol collection tank to achieve methanol fuel recovery. The methanol common rail 1 has a double-layer structure, including an inner pipe 101 and an outer pipe 102. A clamping cavity 103 is provided between the inner pipe 101 and the outer pipe 102. Both ends of the outer pipe 102 are fixedly connected to the inlet flange 7 and the electromagnetic pressure regulator 4, respectively. Both ends of the inner pipe 101 are connected to the inlet flange 7 and the electromagnetic pressure regulator 4, respectively. The rail pipe 1 is connected only to the inner pipe of the inlet flange 7 and the electromagnetic pressure regulating valve 4. The clamping cavity 103 is not connected to the inlet flange 7 and the electromagnetic pressure regulating valve 4. The rail pressure sensor 5 is installed on the outer pipe 102 near the electromagnetic pressure regulating valve 4, and the probe of the rail pressure sensor 5 extends into the inner pipe 101 to detect the methanol fuel pressure in the inner pipe 101. A fresh air pipe 104 connected to the air compressor is also provided on the outer pipe 102 near the inlet flange 7. The fresh air pipe 104 is connected to the inner pipe 101 and is equipped with a solenoid valve 105. An exhaust pipe 106 connected to the inner pipe 101 is also provided on the outer pipe 102 near the electromagnetic pressure regulating valve 4. The end of the exhaust pipe 106 is connected to the methanol pressure relief pipe 8 and is equipped with a switch valve 107. The methanol injection valve 3, the electromagnetic pressure regulating valve 4, the rail pressure sensor 5, the solenoid valve 105, and the switch valve 107 are all electrically connected to the ECU control unit 6.

[0025] In this embodiment of the methanol engine intake manifold multi-point injection system, methanol fuel enters the methanol common rail 1 from the inlet flange 7, and is then injected into the cylinder head intake manifold 2 through the methanol injection valve 3. The rail pressure sensor 5 is used to monitor the rail pressure of the methanol common rail 1 and transmits the rail pressure data to the ECU control unit 6. When the pressure of the methanol common rail 1 is too high, the methanol can be discharged from the methanol pressure relief pipe 8 to the methanol collection tank by controlling the opening of the electromagnetic pressure regulating valve 4, thereby achieving rapid pressure release to control the rail pressure. When the inner pipe 101 is purged, the ECU control unit 6 controls the solenoid valve 105 and the switching valve 107 to open, and compressed air is introduced into the inner pipe 101 to purge the leaked methanol.

[0026] This multi-point injection system connects the inner pipe 101 to the air compressor via a fresh air duct 104 on the methanol common rail 1, and connects the inner pipe 101 to the methanol pressure relief pipe 8 via an exhaust duct 106 on the methanol common rail 1. Before disassembling the pipes for maintenance, fresh air can be blown into the inner pipe 101 to purge the methanol fuel inside the inner pipe 101. The exhaust duct 106 leads to the methanol pressure relief pipe 8, which can blow out the residual methanol fuel and recover it into the container, avoiding the problem of resource waste and meeting the requirements of intrinsically safe engines.

[0027] Preferably, the methanol common rail 1 consists of two double-layered pipe sections connected by a connecting flange 108, and a first sealing gasket 109 is provided between the corresponding connecting flanges 108 of the two double-layered pipe sections to ensure the sealing between the two double-layered pipe sections. Its segmented structure facilitates manufacturing and also makes it easy to align the methanol injection valve with the cylinder head intake port.

[0028] Preferably, one end of the inner tube 101 corresponding to one section of the double-layer pipe is provided with a tapered tube 110, which extends to the outside of the connecting flange 108 corresponding to the double-layer pipe. Correspondingly, one end of the inner tube 101 corresponding to the other section of the double-layer pipe is provided with a tapered cavity 111 adapted to the tapered tube 110. The tapered cavity 111 is located inside the connecting flange 108 corresponding to the double-layer pipe, and the tapered tube 110 is inserted into the tapered cavity 111. A sealing structure is provided between the tapered tube 110 and the tapered cavity 111 to ensure the sealing performance of the inner tube 101. The inner tube 101 corresponding to the methanol common rail pipe 1 is installed by connecting the tapered tube 110 and the tapered cavity 111. The connection surfaces of the inner tube 101 and the outer tube 102 are staggered to avoid stress concentration at the connecting flange 108, effectively extending the service life of the methanol common rail pipe, and further improving the sealing performance of the inner tube.

[0029] Preferably, the sealing structure includes a second sealing gasket 112, which is located at the bottom of the inner cavity of the conical cavity 111. When the connecting flanges 108 corresponding to the two double-layer pipes are connected and tightened, the end of the conical pipe 110 is pressed against the second sealing gasket 112, thereby sealing the inner pipe 101. Further, the sealing structure also includes a sealing ring 113, which is fixed to the outer wall of the conical pipe 110. When the connecting flanges 108 corresponding to the two double-layer pipes are connected and tightened, the outer wall of the sealing ring 113 is pressed against the inner wall of the conical cavity 111, thereby achieving a secondary seal between the conical pipe 110 and the conical cavity 111. This embodiment employs a double-seal method, which can further improve the sealing performance of the inner pipe 101.

[0030] Preferably, each of the two double-layer pipe sections has a uniformly distributed connecting rod 114 fixed to the outer wall of the end of the inner pipe 101 closest to the connecting flange 108. The connecting rods 114 are spaced apart to ensure that the cavities corresponding to the two double-layer pipe sections are connected. The other end of each connecting rod 114 is fixedly connected to the outer pipe 102. In this embodiment, the inner pipe 101 and the outer pipe 102 are connected together by multiple connecting rods 114, which can effectively improve the stability of the inner pipe 101 and the outer pipe 102.

[0031] Preferably, the wall thickness of the inner tube 101 is greater than that of the outer tube 102. The methanol fuel pressure inside the inner tube 101 is high, so a thicker inner tube 101 is used to ensure its structural strength. The clamping cavity 103 does not bear much pressure, so a thinner wall thickness is used.

[0032] The above are merely preferred embodiments of this utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model, and these will not affect the implementation effect of this utility model or the practicality of the patent.

Claims

1. A multi-point injection system for a marine methanol engine intake port, comprising a methanol common rail pipe (1) and a cylinder head air port (2), the methanol common rail pipe (1) being in communication with the cylinder head air port (2) through a plurality of methanol injection valves (3), characterized in that, It also includes an electromagnetic pressure regulating valve (4), a rail pressure sensor (5), and an ECU control unit (6). One end of the methanol common rail (1) is provided with an inlet flange (7), and the other end is connected to the electromagnetic pressure regulating valve (4). The output end of the electromagnetic pressure regulating valve (4) is equipped with a methanol pressure relief pipe (8), which is connected to a methanol collection tank. The methanol common rail (1) includes an inner pipe (101) and an outer pipe (102). A clamping cavity (103) is provided between the inner pipe (101) and the outer pipe (102). Both ends of the outer pipe (102) are fixedly connected to the inlet flange (7) and the electromagnetic pressure regulating valve (4), respectively. Both ends of the inner pipe (101) are connected to the inlet flange (7) and the electromagnetic pressure regulating valve (4), respectively. The rail pressure sensor (5) is installed on the outer pipe (102) near the electromagnetic pressure regulating valve (4). The probe of the rail pressure sensor (5) extends into the inner tube (101). The outer tube (102) near the inlet flange (7) is also provided with a fresh air duct (104) connected to the air compressor. The fresh air duct (104) is connected to the inner tube (101) and is provided with a solenoid valve (105). The outer tube (102) near the electromagnetic pressure regulator (4) is also provided with an exhaust pipe (106) connected to the inner tube (101). The end of the exhaust pipe (106) is connected to the methanol pressure relief pipe (8) and is provided with a switch valve (107). The methanol injection valve (3), electromagnetic pressure regulator (4), rail pressure sensor (5), solenoid valve (105), and switch valve (107) are all electrically connected to the ECU control unit (6).

2. A multi-point injection system for the intake port of a marine methanol engine according to claim 1, characterized in that, The methanol common rail (1) consists of two double-layer pipes connected by a connecting flange (108), and a first sealing gasket (109) is provided between the connecting flanges (108) of the two double-layer pipes.

3. A multi-point injection system for the intake port of a marine methanol engine according to claim 2, characterized in that, One end of the inner tube (101) of one double-layer pipe is provided with a tapered tube (110), which extends to the outside of the connecting flange (108) corresponding to the double-layer pipe. Correspondingly, one end of the inner tube (101) of the other double-layer pipe is provided with a tapered cavity (111) adapted to the tapered tube (110). The tapered cavity (111) is located inside the connecting flange (108) corresponding to the double-layer pipe. The tapered tube (110) is inserted into the tapered cavity (111), and a sealing structure is provided between the tapered tube (110) and the tapered cavity (111).

4. A multi-point injection system for the intake port of a marine methanol engine according to claim 3, characterized in that, The sealing structure includes a second sealing gasket (112), which is located at the bottom of the inner cavity of the conical cavity (111). When the connecting flanges (108) corresponding to the two double-layer pipes are connected and tightened, the end of the conical pipe (110) is pressed against the second sealing gasket (112).

5. A multi-point injection system for the intake port of a marine methanol engine according to claim 4, characterized in that, The sealing structure also includes a sealing ring (113), which is fixed to the outer wall of the tapered tube (110). When the connecting flanges (108) of the two double-layer tubes are connected and tightened, the outer wall of the sealing ring (113) is pressed against the inner wall of the tapered cavity (111).

6. A multi-point injection system for the intake port of a marine methanol engine according to claim 2, characterized in that, The inner tube (101) of the two double-layer tubes is fixed with evenly distributed connecting rods (114) on the outer wall of one end near the connecting flange (108), and the other end of each connecting rod (114) is fixedly connected to the outer tube (102).

7. A multi-point injection system for the intake port of a marine methanol engine according to any one of claims 1 to 6, characterized in that, The wall thickness of the inner tube (101) is greater than that of the outer tube (102).

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