An intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system for ships

Abstract

The present invention relates to a marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system, comprising a linear motor, a symmetrical plunger pump, an accumulator, a reversing valve, an exhaust valve and a controller. The linear motor mover directly drives the symmetrical plunger pump piston, and the two working chambers of the symmetrical plunger pump alternately suck the hydraulic oil in one chamber into the exhaust valve hydraulic cylinder and pump it into the other chamber of the exhaust valve hydraulic cylinder. The flow direction of the hydraulic oil, that is, the movement direction of the exhaust valve, is determined by the three-position four-way reversing valve. When the exhaust valve system is not working, the three-position four-way reversing valve is located in the middle position, the upper and lower chambers of the exhaust valve hydraulic cylinder are connected, and the exhaust valve remains closed under the action of the spring. The controller collects the exhaust valve position signal and outputs the control signal of the linear motor and the reversing valve. The present invention adopts electric hydrostatic actuation technology to realize the intelligent adjustment of the exhaust valve timing, opening duration and lift, integrates the advantages of electromagnetic direct drive and pump-controlled direct drive, is highly efficient and energy-saving, and has a closed hydraulic system with a simple structure and is easy to integrate.

Description

Technical Field

[0001] The invention relates to the technical field of low-speed diesel engine exhaust valves, and in particular to an electric hydrostatic exhaust valve system. Background Art

[0002] In order to improve the economy and low emissions of marine diesel engines, marine low-speed intelligent diesel engines use electronic control units and hydro-pneumatic transmission devices to replace the cam mechanism, and flexibly control the exhaust timing according to changes in operating conditions such as diesel engine speed and load, which has become the direction of technological development.

[0003] At present, the ME-C series engines produced by MAN B&W and the RT-FLEX series engines produced by Wärtsilä both have their own unique hydraulically driven valve distribution systems. Their successful commercial use has provided important reference ideas for researchers at home and abroad. However, the research on the electronically controlled exhaust valve system of domestic low-speed diesel engines is still in its early stages, and basic research on the electronically controlled valve distribution mechanism of medium and small diesel engines has been carried out. The existing electronically controlled exhaust valve system of low-speed diesel engines for ships is composed of a high-pressure servo oil rail and a valve control unit. During operation, the hydraulic pump provides high-pressure hydraulic oil, and then controls the hydraulic oil to drive the exhaust valve through the hydraulic valve. The existing solution requires the hydraulic pump to work for a long time, resulting in increased energy consumption, and the throttling loss of the hydraulic valve control also reduces the system efficiency; at the same time, the required hydraulic pump is large in size, and the layout of the pipeline oil rail is not conducive to system integration, resulting in complex systems and difficult maintenance.

[0004] The present invention adopts electric hydrostatic drive technology to realize intelligent adjustment of exhaust valve timing, opening duration and lift. The linear motor directly drives the hydraulic pump piston to convert mechanical energy into hydraulic energy. The hydraulic pump converts hydraulic energy into exhaust valve mechanical energy through direct volume servo control. The energy transmission path is shortened and the complex valve control unit is simplified. It combines the advantages of electromagnetic direct drive and pump-controlled direct drive, and is highly efficient and energy-saving. The closed hydraulic system has a simple structure and is easy to integrate. Summary of the invention

[0005] The purpose of designing a marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system is to use electric hydrostatic drive technology to achieve intelligent adjustment of exhaust valve timing, opening duration and lift. The linear motor directly drives the hydraulic pump piston to convert mechanical energy into hydraulic energy. The hydraulic pump converts hydraulic energy into exhaust valve mechanical energy through direct volume servo control. The energy transmission path is shortened and the complex valve control unit is simplified. The advantages of electromagnetic direct drive and pump-controlled direct drive are combined to achieve high efficiency and energy saving. The closed hydraulic system has a simple structure and is easy to integrate.

[0006] A marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system comprises a linear motor (1), a plunger pump (2), an accumulator (3), a reversing valve (4), an exhaust valve (5) and a controller (6); the features thereof include: the plunger pump (2) is a single-piston plunger pump with two symmetrical working chambers, the liquid outlet check valve and the liquid inlet check valve are respectively connected to the upper chamber and the lower chamber of the exhaust valve (5) hydraulic cylinder through two pipelines, the accumulator (3) and the reversing valve (4) inlet and outlet are respectively connected to the exhaust valve (5) hydraulic cylinder and the two pipelines of the upper chamber and the lower chamber; the mover of the linear motor (1) directly drives the piston of the plunger pump (2) to reciprocate, and pumps the hydraulic oil in one chamber of the exhaust valve (5) hydraulic cylinder into the other chamber of the exhaust valve (5) hydraulic cylinder, and the hydraulic cylinder of the exhaust valve (5) is a symmetrical hydraulic cylinder; the flow direction of the liquid in the exhaust valve (5) hydraulic cylinder is determined by the reversing valve (4), and the reversing valve (4) is an H-type three-position four-way reversing valve in the middle position; the linear motor (1) adopts a Halbach permanent magnet array to increase the air gap magnetic density, and the linear motor (1) has a moving coil type or a moving magnet type as its mover; the exhaust valve (5) is integrated with an exhaust valve rod, an exhaust valve hydraulic cylinder, an exhaust valve hydraulic cylinder piston, an exhaust valve spring, an exhaust valve spring connecting rod and a displacement sensor; the exhaust valve rod and the exhaust valve spring connecting rod are respectively fixedly connected to the lower end and the upper end of the exhaust valve hydraulic cylinder piston; the exhaust valve spring is installed at the exhaust valve spring connecting rod and is a constant compression spring; the displacement sensor is installed at the upper end of the exhaust valve spring connecting rod, and the position of the exhaust valve (5) is tested through the exhaust valve spring connecting rod; the exhaust valve (5) is integrated with the displacement sensor, and the controller (6) outputs control signals of the linear motor (1) and the reversing valve (4) according to the position signal fed back by the displacement sensor, and the control method comprises the following steps:

[0007] Exhaust valve (5) does not work:

[0008] The plunger pump (2) is not working and the reversing valve (4) is in the middle position, the two chambers of the exhaust valve hydraulic cylinder are connected, and the exhaust valve (5) is closed under the action of its spring;

[0009] Exhaust valve (5) operation:

[0010] S1 The controller (6) controls the cable to input electric energy to the linear motor (1) and the reversing valve (4), the reversing valve (4) switches to the forward position, and the mover of the linear motor (1) reciprocates;

[0011] The mover of the linear motor (1) directly drives the piston of the plunger pump (2) to pump the hydraulic oil in the upper chamber of the hydraulic cylinder of the exhaust valve (5) into the lower chamber of the hydraulic cylinder of the exhaust valve (5);

[0012] S3 The hydraulic oil in the upper chamber of the exhaust valve (5) hydraulic cylinder pushes the piston of the exhaust valve hydraulic cylinder to overcome the exhaust valve spring and the gas load force and move downward, and the exhaust valve (5) opens;

[0013] S4: When the exhaust valve (5) is opened to the target lift, the linear motor (1) stops working and the exhaust valve (5) maintains the target lift;

[0014] S5 The controller (6) controls the cable to input electric energy to the reversing valve (4), the reversing valve (4) switches to the normal reverse position, and the mover of the linear motor (1) reciprocates;

[0015] S6: the mover of the linear motor (1) directly drives the piston of the plunger pump (2) to pump the hydraulic oil in the lower chamber of the hydraulic cylinder of the exhaust valve (5) into the upper chamber of the hydraulic cylinder of the exhaust valve (5);

[0016] S7 The hydraulic oil in the lower chamber of the exhaust valve (5) hydraulic cylinder pushes the exhaust valve hydraulic cylinder piston and the exhaust valve spring to form a combined force to push the exhaust valve (5) upward, and the exhaust valve (5) is closed.

[0017] The piston of the plunger pump (2) is directly connected to the mover of the linear motor (1), and the strokes of the two are the same and smaller than the maximum lift of the exhaust valve (5).

[0018] The controller (6) controls the timing, opening duration and lift of the exhaust valve (5) according to the working conditions of the diesel engine.

[0019] The purpose of the marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system of the present invention is to realize intelligent adjustment of exhaust valve timing, opening duration and lift by electric hydrostatic drive technology. The linear motor directly drives the hydraulic pump piston to convert mechanical energy into hydraulic energy. The hydraulic pump converts hydraulic energy into exhaust valve mechanical energy through direct volume servo control. The energy transmission path is shortened and the complex valve control unit is simplified. The advantages of electromagnetic direct drive and pump-controlled direct drive are combined, and it is highly efficient and energy-saving. The closed hydraulic system has a simple structure and is easy to integrate.

[0020] The linear motor of the present invention directly drives the hydraulic pump piston, eliminating the "rotational-linear motion conversion mechanism", shortening the energy transfer route and improving efficiency; combined with the Halbach permanent magnet array to enhance the air gap magnetic density of the linear motor, the hydraulic pump driving ability and dynamic response performance are improved.

[0021] The present invention is based on direct volume servo control of the hydraulic pump, and the hydraulic pump does not need to work continuously for a long time; the complex hydraulic valve control unit is eliminated, the throttling loss in the system is effectively reduced, and the system efficiency is improved.

[0022] The present invention adopts hydrostatic drive technology, is a closed hydraulic circuit, and has no oil tank, so that the system structure is simple and easy to integrate.

[0023] The intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system for ships of the present invention has a simple structure and is easy to integrate and modularize. It provides a new technical solution for the valve distribution system of low-speed diesel engines, conforms to the current technological development trend of high efficiency and energy saving, and will bring huge economic benefits after being put into industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system of the present invention.

[0025] Figure 2 This is a system liquid flow direction diagram when the marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system of the present invention is opened.

[0026] Figure 3 This is a system liquid flow direction diagram when the marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system of the present invention is closed. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0028] like Figures 1 to 3As shown, a marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system comprises a linear motor (1), a plunger pump (2), an accumulator (3), a reversing valve (4), an exhaust valve (5) and a controller (6); its features include: the plunger pump (2) is a single-piston plunger pump with two symmetrical working chambers, its liquid outlet check valve and liquid inlet check valve are respectively connected to the upper chamber and lower chamber of the exhaust valve (5) hydraulic cylinder through two pipelines, the accumulator (3) and the reversing valve (4) inlet and outlet are respectively connected to the exhaust valve (5) hydraulic cylinder and the two pipelines of the upper chamber and the lower chamber; the mover of the linear motor (1) directly drives the piston of the plunger pump (2) to reciprocate, and pumps the hydraulic oil in one chamber of the exhaust valve (5) hydraulic cylinder into the other chamber of the exhaust valve (5) hydraulic cylinder, and the hydraulic cylinder of the exhaust valve (5) is a symmetrical hydraulic cylinder; the flow direction of the liquid in the exhaust valve (5) hydraulic cylinder is determined by the reversing valve (4), and the reversing valve (4) is connected to the upper chamber and the lower chamber of the hydraulic cylinder. The directional valve (4) is an H-type three-position four-way reversing valve in the middle position; the linear motor (1) adopts a Halbach permanent magnet array to increase the air gap magnetic density, and the linear motor (1) mover is a moving coil type or a moving magnet type; the exhaust valve (5) is integrated with an exhaust valve rod, an exhaust valve hydraulic cylinder, an exhaust valve hydraulic cylinder piston, an exhaust valve spring, an exhaust valve spring connecting rod and a displacement sensor; the exhaust valve rod and the exhaust valve spring connecting rod are respectively fixedly connected to the lower end and the upper end of the exhaust valve hydraulic cylinder piston; the exhaust valve spring is installed at the exhaust valve spring connecting rod and is a constant compression spring; the displacement sensor is installed at the upper end of the exhaust valve spring connecting rod, and the position of the exhaust valve (5) is tested through the exhaust valve spring connecting rod; the exhaust valve (5) is integrated with the displacement sensor, and the controller (6) outputs control signals of the linear motor (1) and the reversing valve (4) according to the position signal fed back by the displacement sensor, and the control method comprises the following steps:

[0029] Exhaust valve (5) does not work:

[0030] The plunger pump (2) is not working and the reversing valve (4) is in the middle position, the two chambers of the exhaust valve hydraulic cylinder are connected, and the exhaust valve (5) is closed under the action of its spring;

[0031] Exhaust valve (5) operation:

[0032] S1 The controller (6) controls the cable to input electric energy to the linear motor (1) and the reversing valve (4), the reversing valve (4) switches to the forward position, and the mover of the linear motor (1) reciprocates;

[0033] The mover of the linear motor (1) directly drives the piston of the plunger pump (2) to pump the hydraulic oil in the upper chamber of the hydraulic cylinder of the exhaust valve (5) into the lower chamber of the hydraulic cylinder of the exhaust valve (5);

[0034] S3 The hydraulic oil in the upper chamber of the exhaust valve (5) hydraulic cylinder pushes the piston of the exhaust valve hydraulic cylinder to overcome the exhaust valve spring and the gas load force and move downward, and the exhaust valve (5) opens;

[0035] S4: When the exhaust valve (5) is opened to the target lift, the linear motor (1) stops working and the exhaust valve (5) maintains the target lift;

[0036] S5 The controller (6) controls the cable to input electric energy to the reversing valve (4), the reversing valve (4) switches to the normal reverse position, and the mover of the linear motor (1) reciprocates;

[0037] S6: the mover of the linear motor (1) directly drives the piston of the plunger pump (2) to pump the hydraulic oil in the lower chamber of the hydraulic cylinder of the exhaust valve (5) into the upper chamber of the hydraulic cylinder of the exhaust valve (5);

[0038] S7 The hydraulic oil in the lower chamber of the exhaust valve (5) hydraulic cylinder pushes the exhaust valve hydraulic cylinder piston and the exhaust valve spring to form a combined force to push the exhaust valve (5) upward, and the exhaust valve (5) is closed.

[0039] The piston of the plunger pump (2) is directly connected to the mover of the linear motor (1), and the strokes of the two are the same and smaller than the maximum lift of the exhaust valve (5).

[0040] The controller (6) controls the timing, opening duration and lift of the exhaust valve (5) according to the working conditions of the diesel engine.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system, comprising a linear motor (1), a plunger pump (2), an accumulator (3), a reversing valve (4), an exhaust valve (5) and a controller (6); its features include: The plunger pump (2) is a single-piston plunger pump with two symmetrical working chambers. Its liquid outlet non-return valve and liquid inlet non-return valve are respectively connected to the upper chamber and lower chamber of the exhaust valve (5) hydraulic cylinder through two pipelines. The inlet and outlet of the accumulator (3) and the reversing valve (4) are respectively connected to the two pipelines of the upper chamber and the lower chamber of the exhaust valve (5) hydraulic cylinder. The mover of the linear motor (1) directly drives the piston of the plunger pump (2) to reciprocate, and pumps the hydraulic oil in one chamber of the exhaust valve (5) hydraulic cylinder into the other chamber of the exhaust valve (5) hydraulic cylinder. The hydraulic cylinder of the exhaust valve (5) is a symmetrical hydraulic cylinder. The flow direction of the liquid in the exhaust valve (5) hydraulic cylinder is determined by the reversing valve (4). The reversing valve (4) is an H-type three-position four-way reversing valve in the middle position. The linear motor (1) adopts a Halbach permanent magnet array to provide The air gap magnetic density is increased, the linear motor (1) has a moving coil type or a moving magnet type as the mover; the exhaust valve (5) is integrated with an exhaust valve rod, an exhaust valve hydraulic cylinder, an exhaust valve hydraulic cylinder piston, an exhaust valve spring, an exhaust valve spring connecting rod and a displacement sensor; the exhaust valve rod and the exhaust valve spring connecting rod are respectively fixedly connected to the lower end and the upper end of the exhaust valve hydraulic cylinder piston; the exhaust valve spring is installed at the exhaust valve spring connecting rod and is a constant compression spring; the displacement sensor is installed at the upper end of the exhaust valve spring connecting rod, and the position of the exhaust valve (5) is tested through the exhaust valve spring connecting rod; the exhaust valve (5) is integrated with the displacement sensor, and the controller (6) outputs control signals of the linear motor (1) and the reversing valve (4) according to the position signal fed back by the displacement sensor, and the control method comprises the following steps: Exhaust valve (5) does not work: The plunger pump (2) is not working and the reversing valve (4) is in the middle position, the two chambers of the exhaust valve hydraulic cylinder are connected, and the exhaust valve (5) is closed under the action of its spring; Exhaust valve (5) operation: S1 The controller (6) controls the cable to input electric energy to the linear motor (1) and the reversing valve (4), the reversing valve (4) switches to the forward position, and the mover of the linear motor (1) reciprocates; The mover of the linear motor (1) directly drives the piston of the plunger pump (2) to pump the hydraulic oil in the upper chamber of the hydraulic cylinder of the exhaust valve (5) into the lower chamber of the hydraulic cylinder of the exhaust valve (5); S3 The hydraulic oil in the upper chamber of the exhaust valve (5) hydraulic cylinder pushes the piston of the exhaust valve hydraulic cylinder to overcome the exhaust valve spring and the gas load force and move downward, and the exhaust valve (5) opens; S4: When the exhaust valve (5) is opened to the target lift, the linear motor (1) stops working and the exhaust valve (5) maintains the target lift; S5 The controller (6) controls the cable to input electric energy to the reversing valve (4), the reversing valve (4) switches to the normal reverse position, and the mover of the linear motor (1) reciprocates; S6: the mover of the linear motor (1) directly drives the piston of the plunger pump (2) to pump the hydraulic oil in the lower chamber of the hydraulic cylinder of the exhaust valve (5) into the upper chamber of the hydraulic cylinder of the exhaust valve (5); S7 The hydraulic oil in the lower chamber of the exhaust valve (5) hydraulic cylinder pushes the exhaust valve hydraulic cylinder piston and the exhaust valve spring to form a combined force to push the exhaust valve (5) upward, and the exhaust valve (5) is closed.

2. The intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system for ships according to claim 1 is characterized in that The piston of the plunger pump (2) is directly connected to the mover of the linear motor (1), and the strokes of the two are the same and smaller than the maximum lift of the exhaust valve (5).

3. The marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system according to claim 1 is characterized in that The controller (6) controls the timing, opening duration and lift of the exhaust valve (5) according to the working conditions of the diesel engine.

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