An automatic freshwater pressure regulating device for engines

Abstract

This utility model discloses an automatic freshwater pressure regulating device for an engine, belonging to the field of engine technology. It includes: an expansion tank, a compressed air source, a control unit, a freshwater inlet temperature sensor, a freshwater inlet pressure sensor, a booster air pressure sensor, and a speed sensor. The freshwater inlet temperature sensor, freshwater inlet pressure sensor, booster air pressure sensor, speed sensor, pressure-replenishing solenoid valve, and pressure-relief solenoid valve are electrically connected to the control unit. This design compares the detected freshwater inlet pressure with a pressure MAP calibrated according to different engine speeds, booster air pressures, and freshwater inlet temperatures. It controls the opening and closing of the pressure-replenishing and pressure-relief solenoid valves to adjust the engine freshwater pressure in a timely and automatic manner, eliminating the risk of cylinder liner and engine block cavitation under low-speed, high-load conditions in marine engines.

Description

Technical Field

[0001] This utility model belongs to the field of engine technology, specifically relating to an automatic freshwater pressure regulating device for engines. Background Technology

[0002] Marine engine expansion tanks are typically installed at a certain height on the ship, either above the engine room or above the deck. To facilitate the addition of freshwater additives, these expansion tanks are mostly open or semi-open structures, lacking pressurization capabilities. Their installation height significantly affects the static water pressure of the entire freshwater circulation system. However, due to hull structure and height limitations, the expansion tank cannot be installed very high, resulting in lower water pressure in the circulation system. Therefore, an engine-driven freshwater pump is used to deliver freshwater to the engine cylinder liners. However, the pressure and flow rate of the freshwater pump are strongly correlated with engine speed; at low engine speeds, the pressure of the entire freshwater circulation system will also be relatively low. Due to limitations imposed by the shape of the freshwater pump's volute and impeller, the correlation curve between the freshwater pump's flow rate, pressure, and engine speed is fixed, lacking independent pressure regulation capabilities.

[0003] When a marine engine operates at low speed and high load, the actual pressure of the fresh water delivered to the cylinder liner wall by the engine-mounted fresh water pump may be lower than the saturated vapor pressure of fresh water due to the low engine speed. The contact surface between the cylinder liner and the fresh water will generate bubbles due to vibration. These bubbles will collapse rapidly during the flow process, generating shock waves and high temperatures, which will cause erosion or damage to the surrounding materials, thus triggering the risk of cavitation erosion of the cylinder liner and engine block. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an automatic freshwater pressure regulating device for engines, which addresses the shortcomings of existing technologies, so as to realize the controllability of freshwater pressure in engines and eliminate the risk of cavitation corrosion of cylinder liners and engine blocks under low speed and high load conditions in marine engines.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0006] An automatic freshwater pressure regulating device for an engine includes: an expansion tank, a compressed air source, and a control unit. A pressure-replenishing solenoid valve is installed on the pressure-replenishing pipeline between the compressed air source and the expansion tank. The expansion tank is connected to the atmosphere via a pressure-relief pipeline, on which a pressure-relief solenoid valve is installed. The device also includes: a freshwater inlet temperature sensor, a freshwater inlet pressure sensor, a boost air pressure sensor, and a speed sensor. The freshwater inlet temperature sensor and the freshwater inlet pressure sensor are installed in the cylinder liner of the engine. The boost air pressure sensor is installed in the boost intake manifold of the engine. The speed sensor is installed at the power output end of the engine. The freshwater inlet temperature sensor, the freshwater inlet pressure sensor, the boost air pressure sensor, the speed sensor, the pressure-replenishing solenoid valve, and the pressure-relief solenoid valve are all electrically connected to the control unit.

[0007] Furthermore, it also includes an engine monitoring device, which is electrically connected to the control unit.

[0008] Furthermore, the expansion tank includes a tank and a tank cover, with the tank cover being sealed to the tank.

[0009] Furthermore, the expansion tank is equipped with a safety valve.

[0010] Furthermore, a freshwater circulation pipeline is connected between the expansion tank and the cylinder liner of the engine, and a freshwater treatment device and a freshwater pump are installed on the freshwater circulation pipeline near the water inlet of the cylinder liner.

[0011] Furthermore, the freshwater treatment device includes a cooling device, a filtration device, and a preheating device.

[0012] Furthermore, the expansion tank is equipped with a liquid level measuring device.

[0013] Furthermore, the expansion tank is connected to a freshwater tank via a water supply pipe, and a water supply valve is installed on the water supply pipe.

[0014] Furthermore, the compressed air source is a compressed air bottle.

[0015] Furthermore, the compressed air cylinder is equipped with a pressure reducing valve at its gas outlet.

[0016] After adopting the above technical solution, the beneficial effects of this utility model are:

[0017] The automatic freshwater pressure regulating device for engines disclosed in this utility model establishes a MAP (Modular Map) for engine speed, boost air pressure, freshwater inlet temperature, and freshwater inlet pressure under various operating conditions. Based on the real-time engine speed, boost air pressure, and freshwater inlet temperature during operation, the device controls the opening and closing of the pressure-replenishing solenoid valve and the pressure-relief solenoid valve to adjust the engine freshwater pressure in a timely and automatic manner to achieve the target value, thereby eliminating the risk of cylinder liner and engine block cavitation under low-speed and high-load conditions in marine engines. At the same time, this device can increase the pressure of the freshwater circulation pipeline and the freshwater inlet pressure, and reduce the freshwater inlet pressure head requirement. Therefore, a freshwater pump with a similar flow rate and lower head can be replaced, reducing the auxiliary power consumed by the freshwater pump, reducing engine fuel consumption, and achieving energy saving and emission reduction. Moreover, this device has fewer restrictions on the installation height of the expansion tank; it only needs to be installed slightly higher than the installation position of other devices in the entire freshwater circulation system. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the automatic freshwater pressure regulating device for engines according to this utility model;

[0019] Figure 2 This is a schematic diagram of the control logic of the automatic freshwater pressure regulating device for engines according to this utility model;

[0020] In the diagram, 1-control unit, 2-wiring harness, 3-engine monitor, 4-engine, 5-freshwater inlet temperature sensor, 6-freshwater inlet pressure sensor, 7-boost air pressure sensor, 8-speed sensor, 9-expansion tank, 10-compressed air cylinder, 11-pressure replenishment pipeline, 12-pressure replenishment solenoid valve, 13-pressure relief pipeline, 14-pressure relief solenoid valve, 15-safety valve, 16-liquid level measuring device, 17-water replenishment pipeline, 18-water replenishment valve, 19-freshwater circulation pipeline, 20-freshwater treatment device, 21-freshwater pump. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the textual part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0022] like Figure 1As shown, an automatic freshwater pressure regulating device for an engine includes: an expansion tank 9, a compressed air source, and a control unit 1. A pressure-replenishing solenoid valve 12 is installed on a pressure-replenishing pipeline 11 between the compressed air source and the expansion tank 9. The expansion tank 9 is connected to the atmosphere via a pressure-relief pipeline 13, on which a pressure-relief solenoid valve 14 is installed. Both the pressure-replenishing solenoid valve 12 and the pressure-relief solenoid valve 14 are normally closed and will not open simultaneously.

[0023] When it is necessary to pressurize the freshwater circulation system, the pressurizing solenoid valve 12 opens, and compressed air enters the expansion tank 9 through the pressurizing pipeline 11, which increases the pressure of the freshwater circulation system and the freshwater inlet pressure, thereby increasing the static water pressure at the cylinder liner wall. When it is necessary to depressurize the freshwater circulation system, the depressurization solenoid valve 14 opens, releasing pressure to the atmosphere and reducing the pressure of the entire freshwater circulation system and the freshwater inlet pressure.

[0024] The automatic freshwater pressure regulation device for the engine in this application further includes: a freshwater inlet temperature sensor 5, a freshwater inlet pressure sensor 6, a boost air pressure sensor 7, and a speed sensor 8. Specifically, the freshwater inlet temperature sensor 5 and the freshwater inlet pressure sensor 6 are installed in the cylinder liner of the engine 4, and are used to detect the temperature and pressure of the freshwater entering the engine 4, respectively. The boost air pressure sensor 7 is installed in the boost air intake manifold of the engine 4, and is used to detect the boost air pressure of the engine. The speed sensor 8 is installed at the power output end of the engine 4, and is used to detect the engine speed.

[0025] The freshwater inlet temperature sensor 5, the freshwater inlet pressure sensor 6, the booster air pressure sensor 7, the speed sensor 8, the pressure replenishing solenoid valve 12, and the pressure relief solenoid valve 14 are electrically connected to the control unit 1. The electrical connections mentioned in this application all refer to connections through the wiring harness 2 to transmit electrical signals.

[0026] The control unit 1, or ECU, integrates the engine speed, boost air pressure, fresh water inlet pressure, and fresh water inlet temperature monitored by various sensors. It compares the actual detected pressure with the MAP calibrated during the development of engine 4. By controlling the on / off state of the pressure replenishment solenoid valve 12 and the pressure relief solenoid valve 14, it ensures that the lower limit of the fresh water inlet pressure is maintained, thereby ensuring that the actual water pressure on the cylinder liner wall is greater than the saturated vapor pressure of fresh water and eliminating the risk of cylinder liner cavitation.

[0027] Furthermore, the automatic freshwater pressure regulating device for the engine in this application also includes an engine monitor 3, which is electrically connected to the control unit 1. The engine speed, boost air pressure, freshwater inlet pressure, and freshwater inlet temperature are displayed by the engine monitor 3.

[0028] In this application, the expansion tank 9 includes a tank and a tank cover. The tank cover is sealed to the tank, enabling the entire freshwater circulation system to achieve a closed function.

[0029] To ensure the safety of the freshwater circulation system, the expansion tank 9 is equipped with a safety valve 15. The pressure relief threshold of the safety valve 15 is slightly higher than that of the pressure relief solenoid valve 14. Therefore, when the pressure relief solenoid valve 14 fails to relieve pressure in time or cannot relieve pressure, the safety valve 15 opens, causing the freshwater circulation system to release pressure and ensuring that the pressure of the entire freshwater circulation system does not exceed the pressure that the pipeline can withstand.

[0030] In this application, a freshwater circulation pipe 19 is connected between the expansion tank 9 and the cylinder liner of the engine 4. A freshwater treatment device 20 and a freshwater pump 21 are installed on the freshwater circulation pipe 19 near the inlet of the cylinder liner. The freshwater treatment device 20 includes a cooling device, a filtering device, and a preheating device, which pre-treats the incoming freshwater by filtering, cooling, or preheating. The freshwater pump 21 is used to increase the pressure and flow rate of the incoming freshwater. Since this device can increase and adjust the pressure of the entire freshwater circulation system, the head requirement of the freshwater pump 21 is reduced, and a small-head freshwater pump 21 can be adapted to reduce the auxiliary power consumed by the freshwater pump 21 and reduce the overall fuel consumption of the engine.

[0031] The expansion tank 9 is equipped with a liquid level measuring device 16, which can be a liquid level gauge. The expansion tank 9 is connected to a fresh water tank through a water supply pipe 17. A water supply valve 18 is installed on the water supply pipe 17. When the liquid level in the expansion tank 9 is too low, the water supply valve 18 can be opened to replenish water through the fresh water tank.

[0032] In this application, the compressed air source is a compressed air cylinder 10. The gas outlet of the compressed air cylinder 10 is equipped with a pressure reducing valve. The pressure reducing valve is used to adjust the pressure of the compressed air entering the fresh water circulation system to adapt to the pressure of the fresh water circulation system.

[0033] like Figure 2 As shown, the control logic of this application is as follows:

[0034] (1) When the engine 4 is running, the control unit 1 processes the speed signal a, the boost air pressure signal b, the fresh water inlet pressure signal c, and the fresh water inlet temperature t collected by the speed sensor 8, the boost air pressure sensor 7, the fresh water inlet pressure sensor 6, and the fresh water inlet temperature sensor 5 respectively, and displays them by the engine monitor 3.

[0035] (2) The control unit 1 compares the collected signals a, b, c, t with the MAP calibrated during the development of the engine 4. When the fresh water inlet pressure c is lower than the required value d, the control unit 1 triggers the pressure compensation solenoid valve 12 to open, and delivers the compressed air in the compressed air bottle 10 to the expansion tank 9 in a sealed state, which causes the pressure of the entire fresh water circulation system to increase and the fresh water inlet pressure to increase, thereby increasing the static water pressure at the cylinder liner wall.

[0036] (3) When the freshwater inlet pressure c rises above e (slightly higher than d), the control unit 1 triggers the pressure replenishment solenoid valve 12 to close, stopping the pressure replenishment;

[0037] (4) When the freshwater inlet pressure c exceeds the limit f, the control unit 1 triggers the pressure relief solenoid valve 14 to open, releasing pressure to the atmosphere and reducing the pressure of the entire freshwater circulation system and the freshwater inlet pressure. When the freshwater inlet pressure is less than f, the control unit 1 triggers the pressure relief solenoid valve 14 to close, stopping the pressure relief.

[0038] (5) When the pressure relief solenoid valve 14 fails to relieve pressure in time or cannot relieve pressure, the pressure of the fresh water circulation system continues to rise. When the pressure reaches the threshold of the safety valve 15, the safety valve 15 (the threshold is slightly larger than f) opens, causing the entire fresh water circulation system to relieve pressure and ensuring that the pressure of the entire fresh water circulation system does not exceed the safety threshold.

[0039] The calibration MAP is based on engine speed, boost air pressure, and freshwater inlet temperature, which limits the lower and upper limits of freshwater pressure under the corresponding conditions of the aforementioned three parameters, so that the pressure of the freshwater circulation system can be automatically adjusted according to different operating conditions.

[0040] The automatic freshwater pressure regulating device for engines of this invention can adjust the engine freshwater pressure in a timely and automatic manner according to the engine speed, boost air pressure, and freshwater inlet temperature under different operating conditions by controlling the opening and closing of the pressure replenishment solenoid valve and the pressure relief solenoid valve, thereby eliminating the risk of cylinder liner and engine block cavitation under low speed and high load conditions of marine engines.

[0041] In the description of this specification, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Unless otherwise expressly defined, terms such as "set," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0042] While specific embodiments of this utility model have been described above, those skilled in the art should understand that the described embodiments are merely some, not all, embodiments of this utility model. These are merely illustrative examples, and the scope of protection of this utility model is defined by the claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model and without any inventive effort, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. An engine fresh water pressure automatic regulating device comprising: The system comprises an expansion tank, a compressed air source, and a control unit. A pressure-replenishing solenoid valve is installed on the pressure-replenishing pipeline between the compressed air source and the expansion tank. The expansion tank is connected to the atmosphere via a pressure-relief pipeline, which is equipped with a pressure-relief solenoid valve. The system is characterized in that... It also includes: a freshwater inlet temperature sensor, a freshwater inlet pressure sensor, a boost air pressure sensor, and a speed sensor. The freshwater inlet temperature sensor and the freshwater inlet pressure sensor are installed in the cylinder liner of the engine. The boost air pressure sensor is installed in the boost air intake manifold of the engine. The speed sensor is installed at the power output end of the engine. The freshwater inlet temperature sensor, the freshwater inlet pressure sensor, the boost air pressure sensor, the speed sensor, the pressure compensation solenoid valve, and the pressure relief solenoid valve are all electrically connected to the control unit.

2. The engine fresh water pressure automatic regulating device according to claim 1, characterized by, It also includes an engine monitoring device, which is electrically connected to the control unit.

3. The engine fresh water pressure automatic regulating device according to claim 1, characterized by, The expansion tank includes a tank and a tank cover, and the tank cover is sealed to the tank.

4. The engine fresh water pressure automatic regulating device according to claim 1, characterized by, The expansion tank is equipped with a safety valve.

5. The engine fresh water pressure automatic regulating device according to claim 1, wherein, A freshwater circulation pipeline is connected between the expansion tank and the cylinder liner of the engine. A freshwater treatment device and a freshwater pump are installed on the freshwater circulation pipeline near the inlet of the cylinder liner.

6. The engine fresh water pressure automatic regulating device according to claim 5, wherein, The freshwater treatment device includes a cooling device, a filtration device, and a preheating device.

7. The engine fresh water pressure automatic regulating device according to claim 1, wherein, The expansion tank is equipped with a liquid level measuring device.

8. The engine fresh water pressure automatic regulating device according to claim 7, wherein, The expansion tank is connected to a freshwater tank via a water supply pipe, and a water supply valve is installed on the water supply pipe.

9. The engine fresh water pressure automatic regulating device according to any one of claims 1 to 8, characterized by, The compressed air source is a compressed air bottle.

10. The engine fresh water pressure automatic regulating device according to claim 9, wherein, The compressed air cylinder is equipped with a pressure reducing valve at its gas outlet.

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