A scavenge device for a marine engine

Abstract

The utility model relates to marine engine technical field, and disclose a marine engine body degassing device, including engine body, cylinder cover, water inlet main pipe and outlet pipe, still include: degassing pipeline assembly, it is configured to integrate in the cooling system loop of engine body, three -way joint is as the core convergence component of degassing pipeline assembly, has first air inlet, second air inlet and air outlet, first exhaust branch, it is connected between the upper air outlet of engine body and the first air inlet of three -way joint. The utility model directly links up the two most easy to accumulate gas parts of engine body and water inlet main pipe and leads to the outlet pipe through degassing pipeline assembly, uses the stable negative pressure that water pump runs at the outlet pipe to form, initiatively, continuously gas is sucked out system, this fundamentally eliminates the negative influence of gas resistance to water pump building pressure, ensures the immediate establishment and stable operation of cooling circulation.

Description

Technical Field

[0001] This utility model relates to the field of marine engine technology, specifically to a degassing device for a marine engine. Background Technology

[0002] Marine engines, especially high-horsepower marine engines, generate a huge amount of heat during operation. The reliability and efficiency of their cooling systems are directly related to the engine's operational safety and lifespan. The cooling system removes heat through circulating coolant, and a key prerequisite for the efficient operation of this system is that the water pump must be able to build up and maintain sufficient pressure (i.e., "pressure build-up") to drive the coolant to circulate continuously and smoothly in components such as the engine block, cylinder head, and radiator.

[0003] However, in actual operation, air can easily get into the cooling system. This air may come from incomplete purging during coolant filling, poor system sealing leading to air intake, or coolant vaporization due to localized high temperatures. The accumulation of air in the system will form "air locks," which severely hinder the flow of coolant. For the water pump, if there are air locks at its inlet, it will prevent it from building up pressure effectively or build up insufficient pressure. Insufficient pressure will further lower the boiling point of the coolant, exacerbate vaporization, and generate more bubbles, creating a vicious cycle. Ultimately, this will cause localized overheating of the engine, which may lead to serious failures such as cylinder head gasket erosion, cylinder head deformation, or even cylinder block damage. This risk is particularly fatal for ships operating at sea.

[0004] In the existing technology, the exhaust of engine cooling systems usually relies on exhaust screws or manual exhaust valves located at local high points. This requires manual operation and has low exhaust efficiency and is incomplete. For complex marine engine cooling circuits, it is difficult to ensure that all gases are effectively discharged, and it cannot fundamentally solve the problem of water pump pressure failure caused by gas storage in the chamber.

[0005] Therefore, there is an urgent need in this field for a dedicated degassing device that can automatically, efficiently, and continuously remove gas from the engine block and key pipelines to ensure rapid and stable pressure build-up of the water pump. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a degassing device for a marine engine. This device can automatically and efficiently collect and discharge gas from the engine body and the water inlet manifold. It uses the system's own pressure difference to smoothly guide the gas into the water outlet circuit, thereby ensuring that the water pump can quickly build up and maintain a stable pressure, ensuring smooth coolant circulation, and preventing engine overheating.

[0007] This utility model discloses a degassing device for a marine engine, comprising an engine block, a cylinder head, a water inlet manifold, and a water outlet manifold, and further comprising: The bleaching line assembly is configured to be integrated into the cooling system circuit of the engine block; The three-way connector, as the core manifold component of the degassing pipeline assembly, has a first air inlet end, a second air inlet end, and an air outlet end; The first exhaust branch is connected between the upper exhaust port of the engine block and the first intake end of the three-way connector, and is used to guide the gas inside the engine block; The second exhaust branch is connected between the upper air outlet of the main water inlet pipe and the second air inlet of the tee connector, and is used to guide the gas in the main water inlet pipe. A negative pressure drainage branch is connected between the air outlet of the tee joint and the water outlet pipe of the engine. The highest point of the negative pressure drainage branch is not lower than the top of the three-way connector, so that the mixed gas collected in the three-way connector can be automatically drawn out and discharged under the drive of negative pressure in the water outlet pipe. The degassing pipeline assembly precisely covers the engine block and the main water inlet pipe, two areas where gas tends to accumulate. It achieves centralized gas collection through dual exhaust branches, with a three-way connector serving as the core of the confluence, simplifying the pipeline layout and ensuring efficient gas convergence. The negative pressure drainage branch utilizes the natural negative pressure of the water outlet pipe to drive the gas out, eliminating the need for an additional power source and achieving passive automatic degassing. The design at the highest point of the branch prevents gas backflow, ensuring continuous degassing and eliminating the impact of air resistance on water pump pressure build-up from the source.

[0008] As a further optimization of this utility model, the first exhaust branch includes a degassing main pipe, which is fixed to the outside of the engine body by a bracket; The bracket ensures the main degassing pipe is installed securely, preventing the pipeline from shifting or being damaged due to severe vibrations during the operation of the marine engine. The external installation method facilitates pipeline maintenance and repair, does not occupy internal engine space, adapts to complex engine structures, and improves the overall reliability of the device.

[0009] As a further optimized solution of this utility model, the first exhaust branch also includes a first degassing connector that connects to the exhaust port of the engine block and a connecting pipe that connects to the first intake end of the three-way connector. The two ends of the degassing main pipe are respectively connected to the first degassing connector and the connecting pipe through a flexible connector. The first degassing connector and connecting pipe achieve precise connection of the pipeline, ensuring smooth gas flow. The flexible connector can buffer vibration and impact, avoiding pipeline fatigue and breakage caused by rigid connection. At the same time, it can adapt to installation deviations, simplify the assembly process, and improve the sealing and durability of pipeline connection.

[0010] As a further optimization of this utility model, the second exhaust branch includes a second degassing connector, which is fixed to the cylinder head of the engine by a pipe clamp. The pipe clamp securely fixes the second exhaust connector to the cylinder head, ensuring the connector position is stable and preventing gas leakage. The fixing method is simple and reliable, easy to install and remove, and adapts to the cylinder head installation space. At the same time, it does not affect the normal operation of the cylinder head and ensures the exhaust efficiency of the second exhaust branch.

[0011] As a further optimization of this utility model, the negative pressure drainage branch includes an air outlet pipe, and the connection point between the air outlet pipe and the water outlet pipe is the highest point of the entire degassing pipeline assembly. The highest point design allows the gas in the system to naturally rise and gather at this position, which facilitates rapid suction under negative pressure, improves degassing efficiency, and at the same time prevents coolant from flowing back into the degassing pipeline, avoids pipeline blockage, ensures the stability and continuity of the degassing process, and is suitable for the complex operating posture of marine engines.

[0012] As a further optimization of this utility model, the outlet of the negative pressure drainage branch is connected to the pipe wall of the water outlet pipe through a flexible connector, and the end of the water outlet pipe is connected to the expansion tank, the installation height of the expansion tank being higher than the highest point of the device. Flexible connectors buffer vibration and ensure connection sealing. The expansion tank is higher than the highest point of the device, and the height difference is used to assist gas-liquid separation. Gas is discharged from the system through the tank pressure relief cover, and the coolant is returned and circulated, achieving synergy between degassing and liquid replenishment. This design further improves the thoroughness of degassing, avoids gas residue, and ensures stable cooling system pressure.

[0013] As a further optimization of this utility model, the flexible connector is a rubber hose, which has good flexibility and sealing performance, can effectively buffer vibration and absorb installation deviation, is suitable for the harsh vibration environment of marine engines, and has corrosion resistance and high temperature resistance to match the working medium and temperature range of the cooling system. It has a long service life, low cost, and is easy to disassemble and assemble, thus reducing maintenance costs.

[0014] As a further optimization of this utility model, in the degassing pipeline assembly, at least the inner diameter of the negative pressure drainage branch is configured to be 3mm. This ensures smooth gas flow while limiting coolant loss, keeping the water flow rate below 1L / min to avoid affecting the main circulation efficiency of the cooling system. Precise pipe diameter control balances the degassing effect and cooling efficiency, ensuring that most of the coolant is used for engine cooling, while achieving efficient degassing and ensuring stable system operation.

[0015] The degassing device for marine engines proposed in this utility model has the following beneficial effects: (i) Through a specially designed degassing pipeline assembly, the engine block and the water inlet manifold, the two parts most prone to gas accumulation, are directly connected and led to the water outlet pipe. The stable negative pressure formed by the water pump running at the water outlet pipe actively and continuously draws the gas out of the system. This fundamentally eliminates the negative impact of air resistance on the water pump pressure building, ensuring the immediate establishment and stable operation of the cooling cycle. (ii) As a passive fluid circuit, the device can work automatically without any human intervention during engine operation. It can respond to the generation of gas in the system in real time and discharge it in a timely manner, realizing the automation and intelligence of the degassing process, which greatly reduces maintenance requirements and the risk of human error. (III) This utility model ingeniously utilizes the inherent pressure distribution of the cooling system, namely, the relative positive pressure at the engine body / inlet main pipe and the negative pressure at the outlet pipe, and realizes the directional delivery of gas through a simple pipeline system. The entire device has a compact structure, is firmly installed by brackets and pipe clamps, has high reliability, and is particularly suitable for marine engines in harsh vibration environments. (iv) By ensuring the effective operation of the cooling system, the risk of engine overheating caused by air resistance and pressure build-up failure is directly avoided. This is crucial for marine engines with high power density and high heat load. It can effectively prevent serious failures such as cylinder head gasket damage and cylinder head cracks, and significantly improve the engine's operational safety and service life.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall assembly of this utility model; Figure 2 A schematic diagram of the degassing pipeline assembly provided by this utility model; Figure 3 A schematic diagram of the pressure build-up test after applying the present invention to a marine engine.

[0018] Figure descriptions: 1. Degassing pipeline assembly; 11. Degassing main pipe; 12. First degassing connector; 13. Connecting pipe; 14. T-connector; 15. Second degassing connector; 16. Exhaust pipe; 17. Bracket; 18. Pipe clamp; 2. Engine block; 3. Cylinder head; 4. Water inlet main pipe; 5. Water outlet pipe; 6. Rubber hose. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0020] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] Please see Figure 1 and Figure 2 The degassing device for marine engines proposed in this utility model includes a degassing pipeline assembly 1 installed on the engine body 2. The engine body 2 is also equipped with a cylinder head 3, a water inlet main pipe 4, and a water outlet pipe 5. The degassing pipeline assembly 1 includes a degassing main pipe 11, a first degassing connector 12, a connecting pipe 13, a tee connector 14, a second degassing connector 15, and an outlet pipe 16; The main exhaust pipe 11 is installed on the outside of the engine block 2 via a bracket 17. The two ends of the main exhaust pipe 11 are respectively connected to the first exhaust connector 12 and the connecting pipe 13. The other end of the first exhaust connector 12 is connected to the exhaust port of the engine block 2. The three-way connector 14 has two air inlets and one air outlet. One air inlet is connected to the other end of the connecting pipe 13, and the other air inlet is connected to the air outlet on the upper surface of the water inlet main pipe 4 through the second degassing connector 15. The air outlet of the three-way connector 14 is connected to the air inlet of the water outlet pipe 5 through the air outlet pipe 16. Among them, the degassing main pipe 11 is connected to the first degassing connector 12, the degassing main pipe 11 is connected to the connecting pipe 13, and the air outlet pipe 16 is connected to the air inlet of the water outlet pipe 5 through a rubber hose 6. The end of the second degassing connector 15 connected to the three-way connector 14 is fixed to the cylinder head 3 through a pipe clamp 18. Furthermore, the exhaust pipe 16 is located at the highest point of the degassing pipe assembly 1. The gas inside the engine block 2 is transmitted to the tee joint 14 through the first degassing connector 12, the main degassing pipe 11 and the connecting pipe 13. Meanwhile, the gas inside the water inlet pipe 4 is transmitted to the tee joint 14 through the second degassing connector 15 and mixed with the gas transmitted from the engine block 2. The mixed gas is then transported from the exhaust end of the tee joint 14 through the exhaust pipe 16 and the hose 6 to the water outlet pipe 5. The outlet end of the water outlet pipe 5 is connected to the expansion tank, and the expansion tank is located above the highest point of the entire device. The expansion tank is a key component in systems such as HVAC, automotive engines, and wall-mounted boilers. Its main functions are to regulate the volume change of liquid in the system, stabilize pressure, vent air, and replenish water. The expansion tank consists of a tank body, a liquid level sensor, a filling cap, a pressure relief cap assembly, and an overflow pipe. The positive pressure opening pressure of the expansion tank pressure relief cap assembly is 100 kPa to 120 kPa, and the negative pressure opening pressure is -2 kPa to 8 kPa.

[0022] In one embodiment, by precisely designing the degassing pipe diameter to 3mm, sufficient free gas and small air bubbles in the cooling system can pass smoothly. Driven by pressure difference, this size of pipe can provide sufficient gas flow to promptly remove gas from the water pump chamber and the highest point of the system, achieving its core degassing function. Moreover, it can generate sufficient flow resistance to the liquid flow. Experimental data shows that, with this diameter, regardless of whether the cooling system is in small circulation (cold engine state, bypassed through the thermostat) or large circulation (hot engine state, through the radiator), the liquid flow rate through the degassing pipe is limited to an extremely low 1L / min. This tiny flow rate has a negligible impact on the main circulation, ensuring that the vast majority of the coolant is used for effective engine cooling.

[0023] The working principle of this invention is based on the ingenious utilization of the inherent pressure field inside the engine cooling system to achieve automatic and directional gas removal, as detailed below: During engine operation, the free gas generated in the cooling system, due to its low density, will naturally rise and accumulate at the high point of the pipeline. Through the first degassing connector 12 and the second degassing connector 15, these gases are precisely arranged in the two "disaster areas" of gas accumulation, namely the engine block 2 and the water inlet main pipe 4, to actively collect these gases. The collected gases are then transported to the three-way connector 14, where gases from different parts are combined. The core driving force of the entire degassing process comes from the water pump. When the engine water pump is running, a stable low-pressure zone is formed in the water outlet pipe 5 at its outlet end, and the outlet of the exhaust pipe 16 is connected to this. At the same time, the pressure inside the engine block 2 and the water inlet main pipe 4 is relatively high due to the pumping action of the water pump. Thus, a natural pressure difference is formed between the inlet and outlet of the degassing pipeline assembly 1, i.e., positive pressure → negative pressure. Driven by this pressure difference, the mixed gas collected in the three-way connector 14 will naturally be drawn into the liquid flow of the water outlet pipe 5 through the highest exhaust pipe 16. After the coolant carrying the gas enters the outlet pipe 5, it will flow to the expansion tank at the rear end (located at the highest point of the system). In the expansion tank, the gas and liquid will naturally separate due to the density difference: the gas will be discharged from the system through the pressure relief cover of the tank, while the coolant will continue to participate in the circulation. Through this series of processes, this invention achieves continuous, automatic, and efficient removal of gas from the cooling system without consuming additional energy or requiring manual intervention.

[0024] like Figure 3 The pressure build-up test data shown confirms that after applying this utility model, the water pump can quickly establish a stable pressure difference of over 20 kPa when the engine starts, and the pressure response is rapid during rapid acceleration. The performance is stable after multiple starts, which fully demonstrates its excellent degassing and pressure holding effects.

[0025] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A degassing device for a marine engine, comprising an engine block (2), a cylinder head (3), a water inlet manifold (4), and a water outlet manifold (5), characterized in that, Also includes: The degassing pipeline assembly (1) is configured to be integrated into the cooling system circuit of the engine block (2); The three-way connector (14), as the core manifold component of the degassing pipeline assembly (1), has a first air inlet end, a second air inlet end and an air outlet end; The first exhaust branch is connected between the upper exhaust port of the engine body (2) and the first intake end of the three-way connector (14) to guide the gas inside the engine body (2); The second exhaust branch is connected between the upper air outlet of the main water inlet pipe (4) and the second air inlet of the three-way connector (14) to guide the gas in the main water inlet pipe (4); A negative pressure drainage branch is connected between the air outlet of the three-way connector (14) and the water outlet pipe (5) of the engine. The highest point of the negative pressure drainage branch is not lower than the top of the three-way connector (14), so that the mixed gas gathered in the three-way connector (14) can be automatically drawn out and discharged under the negative pressure in the water outlet pipe (5).

2. The degassing device for a marine engine according to claim 1, characterized in that, The first exhaust branch includes a venting main pipe (11), which is fixed to the outside of the engine body (2) by a bracket (17).

3. The degassing device for a marine engine according to claim 2, characterized in that, The first exhaust branch also includes a first degassing connector (12) that connects to the exhaust port of the engine block (2) and a connecting pipe (13) that connects to the first intake end of the three-way connector (14). The two ends of the degassing main pipe (11) are respectively connected to the first degassing connector (12) and the connecting pipe (13) through a flexible connector.

4. The degassing device for a marine engine according to claim 1, characterized in that, The second exhaust branch includes a second degassing connector (15), which is fixed to the cylinder head (3) of the engine by a pipe clamp (18).

5. The degassing device for a marine engine according to claim 1, characterized in that, The negative pressure drainage branch includes an air outlet pipe (16), and the connection between the air outlet pipe (16) and the water outlet pipe (5) is the highest point of the entire degassing pipeline assembly (1).

6. The degassing device for a marine engine according to claim 1, characterized in that, The outlet of the negative pressure drainage branch is connected to the wall of the water outlet pipe (5) through a flexible connector, and the end of the water outlet pipe (5) is connected to the expansion tank. The installation height of the expansion tank is higher than the highest point of the device.

7. A degassing device for a marine engine according to claim 3 or 6, characterized in that, The flexible connector is a rubber tube (6).

8. The degassing device for a marine engine according to claim 1, characterized in that, In the degassing pipeline assembly (1), at least the inner diameter of the negative pressure drainage branch is configured to be 3 mm to ensure that the water flow rate during the degassing process does not exceed 1 L / min.

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