External oil-gas separation system of gas engine

Abstract

The invention discloses an external oil-gas separation system of a gas engine, which belongs to the technical field of engines and comprises an oil-gas separator. The oil-gas separator is installed outside the engine, a gas inlet of the oil-gas separator is connected with the gas inlet corrugated pipe, a gas outlet of the oil-gas separator is connected with the pressure limiting valve, and an oil return hose of the oil-gas separator is connected with a crankcase of the engine A plurality of connectors are connected to the air inlet corrugated pipe, and each connector is connected with a crankcase ventilation opening of the crankcase. The outlet end of the pressure limiting valve is connected with an air outlet hose, and the tail end of the air outlet hose is connected to an air inlet pipeline of a supercharger of the engine. The device can improve the filtering efficiency, ventilation is uniform, installation and maintenance are easy and convenient, waste of engine oil is little, and suction pressure can be effectively controlled.

Description

Technical Field

[0001] The present invention belongs to the technical field of engines, and specifically relates to an external oil and gas separation system for a gas engine. Background Art

[0002] During the operation of an internal combustion engine, a part of the unburned combustible mixture and combustion exhaust gas in the cylinder will leak into the crankcase through the gaps between the piston and the cylinder liner. The accumulation of these oil and gas mixtures will increase the pressure in the crankcase, leading to problems such as a decline in engine performance and an increase in fuel consumption. Therefore, it is necessary to discharge them in a timely manner. However, discharging them into the atmosphere does not meet the emission requirements; while directly leading them to the engine intake pipeline, due to the large negative pressure generated in the intake pipeline during the operation of the supercharger, if the suction pressure at the outlet of the oil and gas separation device is not restricted, when the suction pressure is too high, the pressure in the crankcase is too low, resulting in problems such as a decline in cylinder pressure and difficulty in starting the engine, affecting the normal operation of the engine.

[0003] In the prior art, the technical solutions for the oil and gas separation system of engines are shown in patent documents such as those with publication numbers CN 109139189A, CN103184912B, CN215860389U, CN118327738A, etc. The crankcase oil and gas separation devices mostly adopt maze-type, cyclone-type oil and gas separators built into the engine. In order to ensure the filtration efficiency of the oil and gas separator, a multi-stage separation structure is often adopted, that is, two-stage separation (maze pre-separation + cyclone centrifugation), three-stage separation (maze + cyclone + filter element). Although its filtration efficiency is greatly improved, its compact structural form has problems such as high manufacturing difficulty, uneven ventilation effect, and is mostly used in the oil and gas separation field of automotive engines. The existing built-in oil and gas separators will have problems of low separation efficiency and large outlet resistance after being used for a period of time, and need to be maintained regularly and the filter element needs to be replaced to solve the problem. However, the installation space of the built-in oil and gas separator is small, and the installation and disassembly are difficult, which is not convenient for maintenance. In the prior art, the structural forms of the oil and gas separation systems and devices with a pressure limiting function mainly include three types: a mechanical diaphragm and spring driven by the outlet pressure of the oil and gas separator, a rubber diaphragm and spring driven by the negative pressure of the intake system, and a diaphragm and spring driven by the internal pressure feedback of the crankcase. The pressure regulating valves used all drive the diaphragm and spring to work together through pressure changes. The pressure regulating valve and the oil and gas separator mostly adopt an integrated and integrated structure, which is relatively complex and the material of the rubber components used is easy to age, and the maintenance is inconvenient, and it is mostly used for gasoline engines under dynamic working conditions.

[0004] Therefore, for large gas engines, an oil and gas separation system that can meet the oil and gas separation requirements, has high filtration efficiency, good ventilation effect, low resistance, simple and effective structure, convenient installation and maintenance, and can effectively control the suction pressure is needed. Summary of the Invention

[0005] To overcome the deficiencies in the background art, the present invention provides an external oil-gas separation system for a gas engine, aiming to solve the problems in the prior art such as low filtration efficiency, uneven ventilation effect, difficult installation, maintenance and repair, oil waste, exhaust pollution, and inability to effectively control the intake pressure.

[0006] To achieve the above object, the present invention provides the following technical solution: an external oil-gas separation system for a gas engine, comprising a crankcase ventilation port, an intake bellows, an oil-gas separator, a pressure limiting valve, an outlet hose, a return oil hose, and a check valve.

[0007] The crankcase ventilation port is connected to the intake port of the intake bellows through a pipe connector. The intake bellows adopts a telescopic structure type and can freely adjust the number of intake bellows interfaces and the connection position with the crankcase ventilation port according to the ventilation volume of different engine models and different working conditions of the engine.

[0008] Between the intake and outlet ports of the intake bellows is a bellows unit, and each bellows unit has a certain amount of telescopic displacement.

[0009] The intake port of the oil-gas separator is connected to the outlet port of the intake bellows, and the outlet port of the oil-gas separator is connected to the intake side of the pressure limiting valve. The bottom of the oil-gas separator leads into the crankcase through a return oil hose.

[0010] A check valve is added between the return oil hose and the crankcase. When the pressure is abnormal, it restricts the reverse flow of the engine oil in the crankcase.

[0011] The outlet side of the pressure limiting valve is connected to the outlet hose and finally leads to the intake pipe between the air-gas mixer and the turbocharger of the gas engine. The intake side of the pressure limiting valve is connected to the oil-gas separator through a pipe.

[0012] The intake pipe may include an air filter, an air-gas mixer, a turbocharger, and a connecting pipe.

[0013] The pressure limiting valve includes an upper valve body, a lower valve body, a fastener, an O-ring, a spring, and a valve core.

[0014] The upper valve body is of a boss structure type, and the interface is a standard sealed pipe thread. There is a groove in the upper valve body for spring limit.

[0015] The lower valve body is of a boss structure type, and the interface is a standard sealed pipe thread. There is a step in the lower valve body for placing the valve core, and there is a groove in the sealing surface of the lower valve body for O-ring sealing.

[0016] The upper valve body and the lower valve body are flange-connected and axially sealed through a fastener.

[0017] The spool valve described is a conical boss and can be adjusted according to the geometric shape of the valve port.

[0018] The implementation method of the pressure limiting function of the external oil-gas separation system and device: A pressure limiting valve is added between the outlet of the oil-gas separator and the intake pipe between the air-gas mixer of the gas engine and the turbocharger. A spool valve and a return spring are arranged in the pressure limiting valve. When the gas engine is running, due to the suction of the turbocharger, when a negative pressure is generated at the inlet of the intake pipe, the spool valve in the pressure limiting valve will open and move towards the outlet side of the pressure limiting valve. The spool valve described is of a conical boss structural type and can reduce an appropriate part of the valve port under the action of the negative pressure in the intake pipe until the force acting on the spool valve is completely balanced. The return spring described has been adjusted according to the geometric shape of the valve port to ensure the corresponding pressure loss. Its main principle is to increase the resistance flowing through the valve port, thereby increasing the pressure loss between the intake pipe and the outlet side of the pressure limiting valve to relieve the suction pressure at the outlet of the oil-gas separator. Further, a check valve is added between the oil return hose of the oil-gas separator and the crankcase, which restricts the reverse flow of engine oil in the crankcase when the pressure is abnormal.

[0019] Further, the external oil-gas separation system and device with pressure limiting function includes two oil-gas separation system units, and the two oil-gas separation system units respectively form a parallel circuit with the gas engine. One of the oil-gas separation system units consists of a crankcase breather, an intake bellows, an oil-gas separator, a pressure limiting valve, an outlet hose, an oil return hose and a check valve.

[0020] The oil-gas separation system and device described are applicable to the crankcase oil-gas separation system and device for V-type or in-line gas engines under steady-state conditions. The oil-gas separator and the pressure limiting valve are both of external structure. The adjustment mechanism of the pressure limiting valve adopts the negative pressure of the intake system to adjust the return spring and the intake resistance at the spool valve.

[0021] In summary, the beneficial effects of the present invention are as follows: By adopting a telescopic intake bellows unit, the number of intake bellows interfaces and the connection positions with the crankcase ventilation ports can be freely adjusted according to the ventilation volumes of different engine models and different operating conditions of the engine, solving the problems of low filtration efficiency and uneven ventilation effect in the prior art. By adopting an external oil-gas separation system unit, the installation quantity and position of the oil-gas separation system unit can be freely adjusted according to the usage requirements and layout at the engineering site. At the same time, the external oil-gas separation system unit has a simple structure and is convenient for installation, disassembly, and solving the problem of difficult installation, maintenance, and repair in the prior art. At the same time, the external oil-gas separator and related pipelines are far away from the high-temperature engine body, which is beneficial to heat dissipation, reduces the temperature of the oil system, and has better working reliability. By adopting an intake system negative pressure adjustment return spring and an adjustment mechanism for the intake resistance at the valve core, by adding a pressure limiting valve between the oil-gas separator and the intake pipeline and adding a check valve to the oil return pipeline, and leading the separated gas to the intake pipeline between the air-gas mixer and the turbocharger of the gas engine, while meeting the emission requirements and oil recovery, the suction pressure at the outlet of the oil-gas separator is limited, ensuring the stable operation of the gas engine under various operating conditions. In short, the present invention can improve the filtration efficiency, have uniform ventilation, low resistance, be simple in installation, maintenance, and repair, have less oil waste, and can effectively control the suction pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic installation structure diagram of an embodiment of the present invention on an engine;

[0023] Figure 2 is a schematic external shape structure diagram of a pressure limiting valve according to an embodiment of the present invention;

[0024] Figure 3 is a schematic cross-sectional structure diagram of a pressure limiting valve according to an embodiment of the present invention;

[0025] Figure 4 is a schematic pipeline system structure diagram of an embodiment of the present invention.

[0026] In the figure, 1 is the crankcase ventilation port; 2 is the intake bellows; 3 is the oil-gas separator; 4 is the pressure limiting valve; 5 is the outlet hose; 6 is the oil return hose; 7 is the check valve; 8 is the upper valve body; 9 is the lower valve body; 10 is the fastener; 11 is the O-ring; 12 is the spring; 13 is the valve core; 14 is the crankcase; 15 is the mixer; 16 is the air filter; 17 is the turbocharger. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the present invention. Obviously, the described embodiments are only some preferred embodiments of the present invention, rather than all embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0028] Embodiment; Please refer to Figures 1-4 .

[0029] This embodiment provides an external oil-gas separation system for a gas engine, including a crankcase breather port 1, an intake bellows 2, an oil-gas separator 3, a pressure limiting valve 4, an outlet hose 5, a return oil hose 6, and a check valve 7.

[0030] The crankcase breather port 1 is connected to the intake port of the intake bellows 2 through a pipe connector. The intake bellows 2 adopts a telescopic structure type and can freely adjust the number of interfaces of the intake bellows 2 and the connection position with the crankcase breather port 1 according to the ventilation volume of different engine models and different working conditions of the engine.

[0031] Specifically, the intake bellows 2 is provided with two intake ports and one outlet port. The overall structure is a three-way pipe. There is a bellows unit between the two intake and outlet ports. Each bellows unit has a certain amount of telescopic displacement. Further, the number of bellows units can be adjusted according to the number of crankcase breather ports 1 to meet the ventilation requirements.

[0032] The intake port of the oil-gas separator 3 is connected to the outlet port of the intake bellows 2, and the outlet port of the oil-gas separator 3 is connected to the intake side of the pressure limiting valve 4. The outlet side of the pressure limiting valve 4 is connected to the outlet hose 5.

[0033] Specifically, after the oil-gas mixture enters the crankcase 14, it enters the intake bellows 2 through the crankcase breather port 1. After the oil-gas mixture is separated by the oil-gas separator 3, under the action of the negative pressure at the inlet of the intake pipeline, the valve core 13 in the pressure limiting valve 4 will open and move towards the outlet side of the pressure limiting valve 4. The separated gas passes through the pressure limiting valve 4, through the outlet hose 5, and finally leads to the intake pipeline between the air-gas mixer 15 and the turbocharger 17 of the gas engine, and returns to the cylinder to burn again.

[0034] At the same time, the bottom of the oil-gas separator 3 is led into the crankcase 14 through the return oil hose 6 to complete an oil-gas separation cycle. A check valve 7 is added between the return oil hose 6 and the crankcase 14 to limit the reverse flow of engine oil in the crankcase 14 of the gas engine when the pressure is abnormal.

[0035] The pressure limiting valve 4 includes an upper valve body 8, a lower valve body 9, a fastener 10, an O-ring 11, a spring 12, and a valve core 13.

[0036] Specifically, both the upper valve body 8 and the lower valve body 9 are of a boss structure type, and the interfaces are standard sealed pipe threads. There is a groove in the upper valve body 8 for spring 12 positioning. There is a step in the lower valve body 9 for placing the valve core 13, and there is a groove on the sealing surface of the lower valve body 9 for O-ring 11 sealing. The upper valve body 8 and the lower valve body 9 are flange-connected and axially sealed through the fastener 10.

[0037] The pressure limiting valve 4, as an important component of the external oil-gas separation system of the present invention, utilizes the movement of the valve core 13 with a conical boss structure to increase the resistance flowing through the valve port, thereby performing the function of limiting the suction pressure.

[0038] Method for realizing the pressure limiting function of the external oil-gas separation system: Add a pressure limiting valve 4 between the gas outlet of the oil-gas separator 3 and the intake pipeline between the air-gas mixer 15 of the gas engine and the turbocharger 17. A valve core 13 and a return spring 12 are arranged inside the pressure limiting valve 4. During the operation of the gas engine, when a negative pressure is generated at the inlet of the intake pipeline due to the suction of the turbocharger 17, the valve core 13 inside the pressure limiting valve 4 will open and move towards the gas outlet side of the pressure limiting valve 4. The valve core 13 is in the structure form of a conical boss, which can reduce an appropriate part of the valve port under the action of the negative pressure in the intake pipeline until the force acting on the valve core 13 is completely balanced. The return spring 12 has been adjusted according to the geometry of the valve port to ensure the corresponding pressure loss. Its main principle is to increase the resistance flowing through the valve port, thereby increasing the pressure loss between the intake pipeline and the gas outlet side of the pressure limiting valve 4 to relieve the suction pressure at the gas outlet of the oil-gas separator 3. Further, add a one-way valve 7 between the oil return hose 6 of the oil-gas separator 3 and the crankcase 14 to limit the reverse flow of the engine oil in the crankcase 14 when the pressure is abnormal.

[0039] The external oil-gas separation system with pressure limiting function includes two oil-gas separation system units, and the two oil-gas separation system units are respectively in parallel circuits with the gas engine. One of the oil-gas separation system units consists of a crankcase breather 1, an intake bellows 2, an oil-gas separator 3, a pressure limiting valve 4, an outlet hose 5, an oil return hose 6, and a one-way valve 7. As shown in the attached drawing, the double-dashed line frame is an oil-gas separation system unit. The installation quantity and position of the oil-gas separation system unit can be freely adjusted according to the usage requirements and layout at the engineering site. At the same time, the structure of the external oil-gas separation system unit is simple, which is convenient for installation, disassembly, and maintenance.

[0040] The embodiment of the present invention is applied to a V-type or in-line gas engine under a steady-state condition. Both the oil-gas separator 3 and the pressure limiting valve 4 are of an external structure. The adjustment mechanism of the pressure limiting valve 4 adopts the negative pressure of the intake system to adjust the intake resistance at the return spring 12 and the valve core 13.

[0041] The parts not detailed in the present invention are the prior art; for those of ordinary skill in the art, the technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope described in this specification. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An external oil-gas separation system for a gas engine, comprising an oil-gas separator (3); characterized in that: The oil-gas separator (3) is installed outside the engine. Its air inlet is connected to the intake bellows (2), its air outlet is connected to the pressure limiting valve (4), and its oil return hose (6) is connected to the crankcase (14) of the engine; a plurality of connectors are connected to the intake bellows (2), and each connector is connected to a crankcase ventilation port (1) of the crankcase (14); the outlet end of the pressure limiting valve (4) is connected to the outlet hose (5), and the end of the outlet hose (5) is connected to the intake pipeline of the supercharger (17) of the engine; The pressure limiting valve (4) includes an upper valve body (8), a lower valve body (9), a spring (12) and a valve core (13); connection flanges are provided at the docking ends of the upper valve body (8) and the lower valve body (9) for connecting the upper valve body (8) and the lower valve body (9) together through a bolt assembly; a valve core (13) is provided in the lower valve body (9); the spring (12) is sleeved on the valve core (13) for driving the valve core (13) to move towards the intake side of the pressure limiting valve (4); threads are provided at the opposite ends of the upper valve body (8) and the lower valve body (9) for connecting the pipelines on the outlet side and the intake side respectively.

2. The external oil-gas separation system for a gas engine according to claim 1, characterized in that: A groove is provided on the flange surface of the lower valve body (9), and an O-ring (11) is provided in the groove.

3. The external oil-gas separation system for a gas engine according to claim 1, wherein: The oil return hose (6) is provided with a check valve (7) for preventing the oil and gas in the crankcase (14) from flowing back to the oil-gas separator (3).

4. The external oil-gas separation system for a gas engine according to claim 1, wherein: The valve core (13) is a cone with a larger lower part and a smaller upper part, and its larger end abuts against a step preset on the inner wall of the lower valve body (9); the top end of the spring (12) is embedded in a card slot preset in the upper valve body (8).

5. The external oil-gas separation system for a gas engine according to claim 1, wherein: There are two oil-gas separators (3); the corresponding two intake bellows (2) are distributed on the left and right sides of the engine and are respectively used to connect the crankcase ventilation ports (1) of the left and right rows of the engine.

6. The external oil-gas separation system for a gas engine according to claim 1, wherein: A mixer (15) and an air filter (16) are sequentially connected to the intake pipeline of the supercharger (17) of the engine; the end of the outlet hose (5) is connected to the intake pipeline between the mixer (15) and the supercharger (17).

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