CN209925056U - Natural gas engine with partition plate type self-adaptive ventilation system - Google Patents

Abstract

The utility model provides a natural gas engine with clapboard type self-adaptive ventilation system, which comprises an engine body and a ventilation system arranged on the engine body, wherein the ventilation system comprises a primary separation device and a pre-separation device which are arranged on the engine body and are arranged in a mounting groove in a cylinder cover, and an air-driven oil-gas separator fixed on the engine body; the primary separation device is composed of at least two partition plates, an air inlet hole for receiving an oil-gas mixture in a crank case is formed in an installation groove of the cylinder head cover, the cylinder head cover is further provided with an exhaust hole for exhausting separated waste gas, and an air outlet pipe connected with a waste gas inlet of the gas-driven oil-gas separator is arranged on the exhaust hole; the utility model can realize the passive and active separation at the same time, and form the ventilation closed circulation; in addition, the flow rate can be controlled in a self-adaptive mode according to the internal pressure of the separation device, the separation efficiency is improved, and the requirements of the national six-engine can be met.

Description

Natural gas engine with partition plate type self-adaptive ventilation system

Technical Field

The utility model belongs to the engine field, concretely relates to natural gas engine with baffle formula self-adaptation ventilation system.

Background

High-temperature fuel gas generated by the engine during operation can enter the crankcase through a gap between the piston group and the cylinder, so that blow-by gas is generated. The blowby gas is composed of unburned fuel gas, water vapor, exhaust gas, and the like. The water vapor is condensed in the engine oil to dilute the engine oil, so that the service performance of the engine oil is reduced; sulfur dioxide in the waste gas is oxidized in the air to generate sulfuric acid, so that the oxidative deterioration of engine oil is accelerated, and the corrosion and accelerated wear of engine parts can be caused; the blow-by gas also causes the pressure of the crankcase to be too high to damage the sealing of the crankcase, so that the engine oil leaks and runs off; the aging of the engine oil is accelerated, and the reliability is reduced. Therefore, it is desirable to control blow-by gas using a crankcase ventilation system. Blow-by gas can carry a large amount of oil gas when flowing through crankcase ventilation system, causes the engine oil loss, worsens the emission simultaneously, consequently must separate the oil gas, reduces the engine oil loss. The oil and gas discharged by the engine are separated by integrating the oil-gas separator in the cylinder head cover, the cylinder head cover of the traditional engine can only be separated once, and the effect cannot reach the expectation.

Chinese utility model patent as publication No. CN205559013U "a cylinder head cover", including the cylinder head cover body, cylinder head cover body inboard is formed with oil gas preseparation cavity, and this oil gas preseparation cavity is equipped with preseparation air inlet and preseparation gas outlet in advance, follows in the oil gas preseparation cavity the preseparation air inlet arrives the preseparation gas outlet is equipped with in proper order along vertical direction interval arrangement's a plurality of transverse partition plate and is labyrinth interval arrangement's a plurality of longitudinal baffle along the horizontal direction, forms the labyrinth oil gas passageway of intercommunication preseparation air inlet and preseparation gas outlet between transverse partition plate and the longitudinal baffle to it has oil and gas separator to integrate at the cylinder head cover lateral wall. Through the above contents, it can be found that the core of the cylinder head cover oil-gas pre-separation in the prior art lies in the labyrinth oil-gas channel formed between the transverse partition plate and the longitudinal partition plate, but the oil-gas separation capability of the single-layer structure is poor, fine oil drops cannot be separated, and when pressure difference fluctuates in the separation device, the stability of the flow velocity cannot be ensured, the combination of passive separation and active separation cannot be realized, and the requirement of national emission of an engine cannot be met.

For example, the independent externally-hung multi-stage oil-gas separator assembly in the patent of the invention of China with the publication number of CN102705040B is a gas-driven active separator which can actively separate oil-gas mixtures in a crankcase, but the oil-gas mixture can not meet the emission standard of China and the six countries and can not be treated by stages by only adopting an active separating device.

For example, the chinese patent application with publication number CN108049937A, the cylinder head cover built-in oil-gas separation system, built-in oil-gas separator, includes: the labyrinth cavity comprises a cover body, a labyrinth cavity body and a bottom cover, wherein the labyrinth cavity body and the bottom cover are arranged on one side of the cover body; a rough filtering pore plate, a circuitous rectifying structure, a fine filtering pore plate and a position separating plate are arranged in the labyrinth cavity. Through the above contents, it can be found that in the prior art, the cylinder head cover oil-gas pre-separation device is provided with a rough filtering orifice plate and a circuitous rectifying structure, and can be used for oil-gas separation, but super-large oil drops (oil drops with a diameter larger than 10 um) and large oil drops (oil drops with a diameter of 2-10 um) are easily mixed, and oil drop adsorption and flow guide effects are not provided, so that the diameter of oil drops entering the fine filtering orifice plate is still very large, and the device has a very large influence on treatment of small oil drops (oil drops with a diameter of 0.1-2 um); the circuitous rectifying structure disclosed by the prior art cannot solve the problem of secondary crushing (collision splashing) of oil drops generated by high-speed collision of an oil-gas mixture, the oil drops cannot be adsorbed and recovered after flowing through the circuitous rectifying structure, and the oil drops still flow to an outlet along with the oil-gas mixture, so that the separation efficiency is low.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art, and provides a natural gas engine with a clapboard type self-adaptive ventilation system, which can separate ultra-large oil drops, large oil drops and fine oil drops in a grading way, has high separation efficiency, can solve the problems of oil drop adsorption recovery and collision splashing, does not need to regularly maintain and replace a filter element, can simultaneously realize passive and active separation, and forms ventilation closed circulation; in addition, the flow rate can be controlled in a self-adaptive mode according to the internal pressure of the separation device, the separation efficiency is improved, and the requirements of the national six-engine can be met.

The utility model aims at realizing through the following technical scheme:

the utility model provides a natural gas engine with clapboard type self-adaptive ventilation system, which comprises an engine body and a ventilation system arranged on the engine body, wherein the ventilation system comprises a primary separation device and a pre-separation device which are arranged on the engine body and are arranged in a mounting groove in a cylinder cover, and an air-driven oil-gas separator fixed on the engine body; the preliminary separation device is composed of at least two clapboards, an air inlet used for receiving an oil-gas mixture in a crank case is arranged on a mounting groove of the cylinder head cover, the cylinder head cover is also provided with an exhaust hole used for exhausting separated waste gas, and the preliminary separation device comprises:

the coarse separation device consists of a first filter orifice plate and a first filter baffle which are arranged on the bottom plate in parallel, a first oil return cavity on the bottom plate and a first oil return pipe below the first oil return cavity, and the coarse separation device is positioned behind the primary separation device and is used for carrying out accelerated collision on the oil-gas mixture to further separate large oil drops; the fine separation device consists of a second filter pore plate, a filter element, a second filter baffle plate, a second oil return cavity on the bottom plate, a second oil return pipe below the second oil return cavity and a check valve arranged on the second filter pore plate, which are arranged on the bottom plate in parallel, wherein the check valve is not communicated when the internal air pressure is small due to the arrangement of the check valve, and the check valve is communicated to relieve the internal air pressure to ensure the separation effect when the internal air pressure is too large, so that the pre-separation device has the characteristic of self-adaptive pressure regulation; the fine separation device is positioned behind the coarse separation device and used for accelerating collision of the oil-gas mixture again to further separate oil drops, the exhaust hole is arranged behind the fine separation device, and the exhaust hole conveys the separated waste gas to the gas-driven oil-gas separator through the gas outlet pipe;

the exhaust hole is provided with an air outlet pipe connected with a waste gas inlet of the air-driven oil-gas separator; the compressed gas inlet of the gas-driven oil-gas separator is connected with a pressurized intercooling pipeline on the engine body through a gas taking pipe and is used for sucking the pressurized compressed gas of the engine to push an injection pump to generate negative pressure so as to overcome resistance required by collision separation; the mixed gas outlet of the gas-driven oil-gas separator is connected with the gas inlet of a gas compressor on the engine body through a vent pipe so as to realize closed circulation from gas inlet to gas outlet; and an oil return port of the gas-driven oil-gas separator is connected to an oil pan of the engine body through an oil return header pipe.

A first filter hole plate in the coarse separation device is provided with a coarse filter hole for accelerating an oil-gas mixture, in one embodiment, a first filter baffle plate is provided with a filter rib for guiding oil drops to a first oil return cavity, in another embodiment, the first filter baffle plate is provided with a needle-shaped projection part for increasing the contact area of oil-gas collision, and the needle-shaped projection part can effectively prevent the oil drops from being secondarily crushed due to high-speed collision, so that the oil-gas separation efficiency is improved; the first oil return cavity is arranged below the first filter baffle plate, the first filter baffle plate is of a non-closed opening structure so that an oil-gas mixture can flow conveniently, and the first oil return pipe is arranged at the bottom of the first oil return cavity.

In one embodiment, the second filter plate, the filter element and the second filter baffle plate of the fine separation device are arranged against each other on the bottom plate; the second filter hole plate is provided with fine filter holes for carrying out secondary acceleration on the oil-gas mixture; the outlet end of the one-way valve is fixed on the second filter hole plate, and the fine filter holes are formed in the second filter hole plate, so that the outlet end of the one-way valve covers part of the fine filter holes, when the internal pressure of the preseparation device is low, the air pressure is insufficient to impact and open the one-way valve, the oil-gas mixture can be accelerated through the fine filter holes which are not covered by the one-way valve, when the internal pressure of the preseparation device is high to a certain degree, the air pressure is sufficient to impact and open the one-way valve, and part of the oil-gas mixture can flow through the fine filter holes which are covered by the one-way valve; the second is strained and is provided with on the baffle and is used for collision separation oil droplet and water conservancy diversion oil droplet to the second and strain the rib to return oil chamber's two, baffle rear is strained at the second to the second oil chamber setting, the baffle is strained to the second and is non-confined open structure, the second returns oil pipe setting and returns oil chamber's bottom at the second.

In one embodiment, the pre-separation device further comprises a concave baffle, the concave baffle is of an open structure so as to form an oil-gas channel, and the concave baffle is further provided with three filter ribs for colliding and separating oil drops and guiding the oil drops to the second oil return cavity; the oil-gas mixture impacts the concave baffle, oil drops flow into the second oil return cavity through the three filter ribs, and the rest of the oil-gas mixture flows into the exhaust hole through the opening structure (oil-gas channel) of the concave baffle.

In one embodiment, umbrella-shaped oil return valves for preventing exhaust gas from backflushing to enter the preseparation device are further arranged on the first oil return pipe and the second oil return pipe, so that the influence on oil-gas preseparation efficiency caused by the exhaust gas backflushing can be effectively prevented.

In one embodiment, the material of the filter element is any one of non-woven fabric, felt, glass fiber and synthetic fiber.

In an embodiment, the interval of first filtration pore board and first filtration baffle is 2 ~ 5mm, according to the air input size of inlet port, the aperture of coarse filtration pore can set up to 3 ~ 6mm, the number of coarse filtration pore sets up to 10 ~ 45, makes the velocity of flow control through first filtration pore board at 5 ~ 8m/s, and the first filtration pore board oil-gas mixture of flowing through is effectual with first filtration baffle striking separation oil drop at this velocity of flow within range.

In one embodiment, according to the size of the air inflow of the air inlet hole, the aperture of the fine filtering holes can be set to be 2-3 mm, the number of the fine filtering holes is set to be 10-54, the flow speed passing through the second filtering hole plate is controlled to be 15-30 m/s, and the effect of separating oil drops by the collision of the oil-gas mixture flowing through the second filtering hole plate and the second filtering baffle in the flow speed range is good.

Compared with the prior art, the utility model has the advantages of:

the natural gas engine with the partition plate type self-adaptive ventilation system can accelerate an oil-gas mixture twice, separate large oil drops and small oil drops respectively and flow out through the oil return cavity, and is high in separation efficiency; on the adsorption of the oil drops, the filter element is not blocked by residues due to the impact force of secondary acceleration, so that the filter element does not need to be replaced periodically, and the problem of periodic replacement and maintenance can be solved; in addition, the natural gas engine with the clapboard type self-adaptive ventilation system achieves the effect of self-adaptively adjusting the internal pressure of the pre-separation device by arranging the one-way valve, and realizes the new effect of self-adaptive pressure adjustment generated by the combination of the one-way valve and the second filter hole plate; this natural gas engine with baffle formula self-adaptation ventilation system can also predetermine the specification of coarse filtration pore and fine filtration pore according to the size of air input to this flow velocity after the guarantee once accelerates and the secondary accelerates promotes the efficiency that the striking separation oil drips.

Drawings

Embodiments of the invention are further described below with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of an engine according to an embodiment of the present invention;

fig. 2 is a schematic view of a ventilation system according to an embodiment of the present invention;

fig. 3 is a schematic view of the internal structure of a cylinder head cover according to an embodiment of the present invention;

fig. 4 is a schematic three-dimensional structure diagram of a cylinder head cover mounting groove according to an embodiment of the present invention;

fig. 5 is a schematic cross-sectional view of a cylinder head cover mounting groove according to an embodiment of the present invention;

FIG. 6 is a schematic three-dimensional view of a preseparation device according to an embodiment of the present invention;

fig. 7 is a schematic three-dimensional structure of a first filter aperture plate and a first filter baffle according to an embodiment of the present invention;

fig. 8 is a schematic three-dimensional view of a first filter baffle having needle-like protrusions according to an embodiment of the present invention;

fig. 9 is a schematic three-dimensional view of a second filter plate, a filter element, a second filter baffle, and a one-way valve according to an embodiment of the present invention;

FIG. 10 is a schematic view of the outlet end of the check valve covering the fine filter aperture according to one embodiment of the present invention;

fig. 11 is a schematic three-dimensional structure of a concave baffle according to an embodiment of the present invention;

fig. 12 is a schematic view of a separation structure of two separators according to an embodiment of the present invention;

fig. 13 is a schematic diagram of a separation structure of four separators according to an embodiment of the present invention;

fig. 14 is a schematic structural view of an outlet pipe of a cylinder head cover according to an embodiment of the present invention;

fig. 15 is a schematic structural diagram of an air-driven oil-gas separator according to an embodiment of the present invention;

fig. 16 is a schematic diagram illustrating the operation of the check valve in the on state according to an embodiment of the present invention.

In the figure, 100 is an engine body, 101 is a fixing frame, 200 is a cylinder head cover, 201 is an air inlet, 202 is a mounting groove, 203 is an exhaust hole, 204 is an air outlet pipe, 205 is an air taking pipe, 206 is an oil return header pipe, 207 is a vent pipe, 300 is an air-driven oil-gas separator, 301 is an exhaust gas inlet, 302 is a compressed gas inlet, 303 is a mixed gas outlet, 304 is an oil return port, 400 is a primary separation device, 401 is a first partition plate, 402 is a second partition plate, 403 is a third partition plate, 404 is a fourth partition plate, 500 is a pre-separation device, 501 is a bottom plate, 504 is a concave baffle plate, 505 is a first filter hole plate, 506 is a first filter baffle plate, 507 is a first oil return hole, 508 is a first oil return pipe, 509 is a second filter hole plate, 510 is a filter core, 511 is a second filter baffle plate, 512 is a second oil return cavity, 513 is a second oil return pipe, 514 is a one-way valve, 515 is a coarse filter hole, 516 is a filter rib, 518 is two filter ribs, 519 is three filter ribs, 520 is a needle-shaped projection.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly apparent, the present invention is further described in detail by the following embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

The embodiment of the utility model provides a natural gas engine with baffle type self-adaptation ventilation system, as shown in fig. 1, 2, including engine block 100 and the ventilation system that sets up on engine block 100, the ventilation system includes that set up on engine block 100 in the cylinder head cover 200 installation groove 202 primary separator 400 and pre-separator 500 (as shown in fig. 3, 4), and fix the oil-gas separator 300 of gas drive on engine block 100 through mount 101; the primary separation device 400 is composed of at least two partition plates; as shown in fig. 4, an air intake hole 201 for receiving an oil-gas mixture in a crankcase is opened on an installation groove 202 of the cylinder head cover 200, and the cylinder head cover 200 is further provided with an exhaust hole 203 for exhausting separated exhaust gas;

the preliminary separation device 400 is arranged behind the air inlet 501 and used for preliminarily separating the oil-gas mixture, and separating oil drops with the diameter larger than 10um in the oil-gas mixture, as shown in fig. 5 and 6, the preliminary separation device 500 comprises a first filter hole plate 505 and a first filter baffle 506 which are arranged on the bottom plate 501 in parallel, a first oil return cavity 507 on the bottom plate 501 and a coarse separation device formed by a first oil return pipe 508 on the lower portion of the first oil return cavity, and the coarse separation device is located behind the preliminary separation device 400 and used for treating large oil drops (the diameter of the oil drops is 2-10 um) in the oil-gas mixture; the oil-gas separation device comprises a second filter pore plate 509, a filter element 510, a second filter baffle 511, a second oil return cavity 512 on the bottom plate 501, a second oil return pipe 513 on the lower part of the second oil return cavity, and a one-way valve 514 arranged on the second filter pore plate 509, wherein the fine separation device is positioned behind the coarse separation device and is used for treating oil droplets (the diameter of the oil droplets is 0.1-2 um) in an oil-gas mixture; the exhaust hole 203 of the cylinder head cover 200 is provided behind the fine separation means for discharging exhaust gas after oil drops are separated,

the exhaust hole 203 is further provided with an outlet pipe 204 (as shown in fig. 14) for discharging an oil-gas mixture, the outlet pipe 204 is connected with the exhaust hole 203 and penetrates out of the cylinder head cover 200, the outlet pipe 204 is arranged to guide the pre-separated oil-gas mixture into an exhaust gas inlet 301 of the gas-driven oil-gas separator 300, the gas-driven oil-gas separator 300 adopts the existing conventional equipment (such as a cyclone separator), as shown in fig. 15 and 2, a compressed gas inlet 302 of the gas-driven oil-gas separator 300 is connected with a boosting medium-cooling pipeline on the engine body 100 through an air intake pipe 205 and is used for sucking the compressed gas after boosting of the engine to push the jet pump to generate negative pressure to overcome resistance required by collision separation; the mixed gas outlet 303 of the gas-driven oil-gas separator 300 is connected with an air inlet (not shown) of a compressor on the engine body 100 through a vent pipe 207 so as to realize closed circulation from air inlet to air outlet; the oil return port 304 of the gas-driven oil-gas separator is connected to the oil pan of the engine body 100 through the oil return header pipe 206, so that the passive and active separation of the oil-gas mixture in the crankcase is finally realized, and the closed circulation of the ventilation system is also realized, so that the separation effect reaches the emission standard of the national six-engine.

In one embodiment, as shown in fig. 12, the preliminary separation apparatus 400 is composed of first and second partition plates 401 and 402, respectively, which are fixed to the inner walls of both ends of the installation groove 202 to form a curved labyrinth oil and gas passage, and in another embodiment, as shown in fig. 13, the preliminary separation apparatus 400 is composed of first and second partition plates 401 and 402, respectively, third and fourth partition plates 403 and 404, respectively, which are fixed to the inner walls of both ends of the installation groove 202 in a staggered manner to form a curved labyrinth oil and gas passage.

As shown in fig. 6, a first filter orifice plate 505 and a first filter baffle 506 in the coarse separation device are arranged in parallel on the bottom plate 501, and a coarse filter orifice 515 (shown in fig. 7) for performing primary acceleration on the oil-gas mixture is arranged on the first filter orifice plate 505. In one embodiment, the first filtering baffle 506 is provided with a filtering rib 516 for separating large oil drops (with an oil drop diameter of 2-10 um) by collision and guiding the large oil drops to the first oil return cavity 507, the first oil return cavity 507 is arranged below the first filtering baffle 506, the first filtering baffle 506 is of an unclosed open structure (so as to form an oil-gas channel), and the first oil return pipe 508 is arranged at the bottom of the first oil return cavity 507; the oil-gas mixture is accelerated by the first filter orifice plate 505 and then collides with the first filter baffle 506, large oil drops flow into the first oil return cavity 507 through a filter rib 516, and the rest of the oil-gas mixture flows out through the opening part (oil-gas channel) of the first filter baffle 506; in another embodiment, as shown in fig. 8, a needle-shaped protrusion 520 for increasing the oil-gas collision contact area is disposed on the first filter baffle 506, the needle-shaped protrusion 520 can effectively adsorb large oil drops colliding with the first filter baffle 506 at a high speed and guide the oil drops to the first oil return cavity 507, so as to prevent the large oil drops from being broken again due to the high-speed collision (splash is easily generated due to the collision of the large oil drops), thereby improving the oil-gas separation efficiency, the large oil drops flow into the first oil return cavity 507 through the needle-shaped protrusion 520, and the rest of the oil-gas mixture flows out through the opening portion (oil-gas passage) of the first filter baffle 506. In one embodiment, if the intake air amount of the intake hole 201 is 60L/min, the aperture of the coarse filter holes 515 is set to 3mm, the number of the coarse filter holes 515 is set to 27, and the distance between the first filter hole plate 505 and the first filter baffle 506 is set to 2mm, so that the flow rate through the first filter hole plate 505 is controlled to be about 5m/s, and at this time, the oil-gas mixture flowing through the first filter hole plate 505 has a good impact separation effect with the first filter baffle 506 under the setting of the flow rate and the distance; in another embodiment, if the intake air amount of the intake hole 201 is 100L/min, the aperture of the coarse filter hole 515 is set to 6mm, the number of the coarse filter holes 515 is set to 10, and the distance between the first filter plate 505 and the first filter baffle 506 is set to 3mm, so that the flow rate through the first filter plate 505 is controlled to be about 6m/s, and at this time, the oil-gas mixture flowing through the first filter plate 505 has a good impact separation effect with the first filter baffle 506 under the setting of the flow rate and the distance; in another embodiment, if the intake air amount of the intake hole 201 is 150L/min, the aperture of the coarse filter hole 515 is set to 5mm, the number of the coarse filter holes 515 is set to 25, and the distance between the first filter hole plate 505 and the first filter baffle 506 is set to 5mm, so that the flow rate passing through the first filter hole plate 505 is controlled to be about 5m/s, and at this time, the oil-gas mixture flowing through the first filter hole plate 505 has a good impact separation effect with the first filter baffle 506 under the setting of the flow rate and the distance; in another embodiment, if the air intake amount of the air intake hole 201 is 270L/min, the aperture of the coarse filter hole 515 is set to 6mm, the number of the coarse filter holes 515 is set to 20, and the distance between the first filter plate 505 and the first filter baffle 506 is set to 4mm, so that the flow rate through the first filter plate 505 is controlled to be about 8m/s, and at this time, the oil-gas mixture flowing through the first filter plate 505 has a good impact separation effect with the first filter baffle 506 under the setting of the flow rate and the distance; in another embodiment, if the intake air amount of the intake hole 201 is 270L/min, the aperture of the coarse filter hole 515 is set to 3mm, the number of the coarse filter holes 515 is set to 45, and the distance between the first filter plate 505 and the first filter baffle 206 is set to 4mm, so that the flow rate through the first filter plate 505 is controlled to be about 8m/s, and at this time, the oil-gas mixture flowing through the first filter plate 505 has a good impact separation effect with the first filter baffle 506 under the setting of the flow rate and the distance.

In one embodiment, as shown in fig. 6, the second filter hole plate 509, the filter element 510 and the second filter baffle 511 of the fine separation device are arranged on the bottom plate 501 closely to each other, and the second filter hole plate 509 is provided with a one-way valve 514; be provided with on the second filter pore board 509 and be used for carrying out the fine filtration hole 517 of secondary acceleration to oil gas mixture, when oil gas mixture flows through second filter pore board 509, oil gas mixture has carried out the secondary acceleration under the effect of fine filtration hole 517, and oil gas mixture can be right filter core 510 carries out high-speed impact, the filter core 510 lower part is the open architecture and is convenient for form the oil gas passageway, filter core 510 is used for adsorbing the oil droplet (it means oil droplet diameter is 0.1 ~ 2 um) after oil gas mixture secondary acceleration, and wherein the material of filter core 510 can be non-woven fabrics, felt, glass fiber or synthetic fiber, and filter core 510 adopts these materials to adsorb oil droplet effect good, and under the high-speed impact effect of secondary acceleration, its surface can not gather the residue, therefore can avoid regularly changing the maintenance (directly adopt the filter cotton to carry out oil gas separation in the prior art, its efficiency is high, but the filter cotton needs to be replaced and maintained regularly, and the maintenance cost is high); as shown in fig. 9 and 10, the outlet end of the check valve 514 is fixed on the second filter hole plate 509, because the second filter hole plate 509 is provided with the fine filter hole 517, the outlet end of the check valve 514 covers part of the fine filter hole 517, when the internal pressure of the preseparation device 500 is low, the air pressure is not enough to impact and open the check valve 514, the oil-gas mixture can be accelerated through the fine filter hole 517 uncovered by the check valve 514, when the internal pressure of the preseparation device 500 is high to a certain extent (when the flow rate of the oil-gas mixture is greater than 18.2 m/s), the air pressure is enough to impact and open the check valve 514, and part of the oil-gas mixture flows through the fine filter hole 517 covered by the check valve 514, so as to achieve the effect of adaptively adjusting; the principle of the check valve 514 is that in the initial state, the top cover of the check valve props against the inlet end by means of the elastic force of the spring, only when the pressure at the inlet end is higher than a certain degree, the top cover compresses the spring to conduct the check valve (as shown in fig. 16), and at the moment, the medium can enter through the inlet end and flow out from the fine filter hole covered by the outlet end; the second filtering baffle 511 is provided with two filtering ribs 518 for separating oil droplets by collision and guiding the oil droplets to the second oil return cavity 512, the lower part of the second filtering baffle 511 is of a non-closed opening structure (forming an oil-gas channel) so as to facilitate the flow of an oil-gas mixture, the oil-gas mixture flows through the filter element 510, the oil droplets flow into the second oil return cavity through the two filtering ribs 518 under the impact action of the second filtering baffle 511, and the rest of the oil-gas mixture enters the next-stage separation device through the opening structure (the oil-gas channel) of the second filtering baffle 511; in one embodiment, if the air intake amount of the air intake hole 201 is 60L/min, the aperture of the fine filter hole 517 is set to be 2mm, and the number of the fine filter holes 517 is set to be 22 (where the outlet end of the check valve 514 covers 4, the outlet end of the check valve 514 does not cover 18, and the oil-gas mixture can pass through the 18 uncovered fine filter holes 517), at this time, the air pressure inside the preseparation device 500 is not enough to conduct the check valve 514, the flow rate passing through the second filter hole 509 is controlled to be about 18m/s, the oil-gas mixture flowing through the second filter hole 509 impacts the filter element 510 at this flow rate, and the oil-gas mixture after adsorbing small oil drops continues to impact the second filter baffle 511 at this flow rate, so as to obtain a better small oil drop separation effect; when the air inflow of the air inlet hole 201 is increased from 60L/min to 78L/min, the air pressure in the preseparation device 500 is increased, the check valve 514 is conducted under the impact of the air pressure (the oil-gas mixture can pass through 22 fine filter holes 517), at this time, the flow rate passing through the second filter hole plate 509 is controlled to be about 18.8m/s, the oil-gas mixture passing through the second filter hole plate 509 impacts the filter element 510 under the flow rate, the oil-gas mixture after the filter element 510 absorbs oil drops continuously impacts the second filter baffle 511 under the flow rate, and a good oil drop separation effect can be obtained; in another embodiment, if the air intake amount of the air intake hole 201 is 60L/min, the aperture of the fine filter hole 517 is set to be 3mm, the number of the fine filter holes 517 is set to be 10 (wherein the outlet end of the check valve 514 covers 2, the outlet end of the check valve 514 does not cover 8, and the oil-gas mixture can pass through the 8 uncovered fine filter holes 517), so that the flow rate passing through the second filter hole plate 509 is controlled to be about 17.7m/s, at this time, the air pressure inside the preseparation device 500 is not enough to conduct the check valve 514, the oil-gas mixture flowing through the second filter hole plate 509 impacts the filter element 510 at the flow rate, and the oil-gas mixture after adsorbing small oil drops on the filter element 510 continuously impacts the second filter baffle 511 at the flow rate, so as to obtain a better oil drop separation; when the air inflow of the air inlet hole 201 is increased from 60L/min to 80L/min, the air pressure in the preseparation device 500 is increased, the check valve 514 is conducted under the impact of the air pressure (the oil-gas mixture can pass through 10 fine filter holes 517), so that the flow rate passing through the second filter hole plate 509 is controlled to be about 18.9m/s, the oil-gas mixture passing through the second filter hole plate 509 impacts the filter element 510 under the flow rate, the oil-gas mixture after the filter element 510 absorbs oil drops continuously impacts the second filter baffle 511 under the flow rate, and a better oil drop separation effect can be obtained; in another embodiment, if the air intake amount of the air intake hole 201 is 120L/min, the aperture of the fine filter hole 517 is set to be 2.5mm, and the number of the fine filter holes 517 is set to be 30 (where the outlet end of the check valve 514 covers 6, the outlet end of the check valve 514 covers 24, and the oil-gas mixture can pass through the uncovered 24 fine filter holes 517), so that the flow rate passing through the second filter hole 509 is controlled to be about 17m/s, at this time, the air pressure inside the preseparation device 500 is not enough to conduct the check valve 514, the oil-gas mixture flowing through the second filter hole 509 impacts the filter element 510 at the flow rate, and the oil-gas mixture after adsorbing small oil drops by the filter element 510 continuously impacts the second filter baffle 511 at the flow rate, so as to obtain a better oil drop separation effect; when the air inflow of the air inlet hole 201 is increased to 165L/min from 120L/min, the air pressure in the preseparation device 500 is increased, the check valve 514 is conducted under the impact of the air pressure (the oil-gas mixture can pass through 30 fine filter holes 517), so that the flow rate passing through the second filter hole plate 509 is controlled to be about 18.7m/s, the oil-gas mixture passing through the second filter hole plate 509 impacts the filter element 510 under the flow rate, the oil-gas mixture after the filter element 510 absorbs oil drops continuously impacts the second filter baffle 511 under the flow rate, and a good oil drop separation effect can be obtained; in another embodiment, if the air intake amount of the air intake hole 201 is 200L/min, the aperture of the fine filter hole 517 is set to be 2.4mm, and the number of the fine filter holes 517 is set to be 54 (where the outlet end of the check valve 514 covers 12, the outlet end of the check valve 514 covers 42, and the oil-gas mixture can pass through the uncovered 42 fine filter holes 517), so that the flow rate passing through the second filter hole 509 is controlled to be about 17.5m/s, at this time, the air pressure inside the preseparation device 500 is not enough to conduct the check valve 514, the oil-gas mixture flowing through the second filter hole 509 impacts the filter element 510 at the flow rate, and the oil-gas mixture after the filter element 510 adsorbs oil drops continuously impacts the second filter baffle 511 at the flow rate, so as to obtain a good oil drop separation effect; when the air inflow of the air inlet hole 201 is increased from 200L/min to 270L/min, the air pressure in the preseparation device 500 is increased, the check valve 514 is conducted under the impact of the air pressure (the oil-gas mixture can pass through 54 fine filter holes 517), so that the flow rate passing through the second filter hole plate 509 is controlled to be about 18.4m/s, the oil-gas mixture passing through the second filter hole plate 509 impacts the filter element 510 under the flow rate, the oil-gas mixture after the filter element 510 adsorbs oil drops continuously impacts the second filter baffle 511 under the flow rate, and a good oil drop separation effect can be obtained.

In one embodiment, as shown in fig. 5 and fig. 6, the preseparation device 500 further includes a concave baffle 504, the concave baffle 504 is an open structure to facilitate formation of an oil-gas channel, as shown in fig. 11, the concave baffle 504 is further provided with three filter ribs 519 for collision separation of oil droplets and guiding to the second oil return chamber 512; the oil-gas mixture strikes concave baffle 504, and oil drops flow into second oil return chamber 512 through three filter ribs 519, and other oil-gas mixtures flow through concave baffle 504's open structure and get into exhaust hole 203, the ascending fixing of concave baffle 504 opening is on bottom plate 501 to oil-gas mixture directly strikes concave baffle 504 lower part, and oil drops flow into second oil return chamber 212 through three filter ribs 519 under the action of gravity.

In an embodiment, with continued reference to fig. 6, an umbrella-shaped oil return valve (not shown) for preventing exhaust gas from backflushing into the preseparation device 500 is further disposed on the first oil return pipe 508 and the second oil return pipe 513, so as to effectively prevent the oil-gas preseparation efficiency from being affected by the exhaust gas backflushing.

For other structures of the natural gas engine, please refer to the prior art, and detailed description thereof is omitted.

Compared with the prior art, the natural gas engine with the clapboard type self-adaptive ventilation system can separate partial oil drops in the air inlet stage of the oil-gas mixture, then accelerates the oil-gas mixture twice, separates large oil drops and small oil drops respectively and flows out through the oil return cavity, and has high separation efficiency; in addition, the natural gas engine with the partition type self-adaptive ventilation system achieves the effect of self-adaptively adjusting the internal pressure of the pre-separation device by arranging the check valve, can deal with the problem that the internal air pressure of the pre-separation device is too large after the air input is increased, and finally can meet the national emission standard.

Reference in the specification to "some embodiments," "one embodiment," or "an embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," or the like, in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, a particular feature, structure, or characteristic illustrated or described in connection with one embodiment may be combined, in whole or in part, with a feature, structure, or characteristic of one or more other embodiments without limitation, as long as the combination is not logical or operational. Additionally, the various elements of the drawings of the present application are merely schematic illustrations and are not drawn to scale.

Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention.

Claims (5)

1. A natural gas engine with a partition type self-adaptive ventilation system comprises an engine body and a ventilation system arranged on the engine body, wherein the ventilation system comprises a primary separation device and a pre-separation device which are arranged in an installation groove in a cylinder cover on the engine body, and an air-driven oil-gas separator fixed on the engine body; the primary separation device is composed of at least two clapboards and is characterized in that:

the mounting groove of cylinder head cover has been seted up the inlet port, the cylinder head covers and still is equipped with the exhaust hole, preseparation device includes:

the coarse separation device consists of a first filter hole plate and a first filter baffle which are arranged on the bottom plate in parallel, a first oil return cavity on the bottom plate and a first oil return pipe below the first oil return cavity, and the coarse separation device is positioned behind the primary separation device; a first filter hole plate in the coarse separation device is provided with a coarse filter hole, a first filter baffle plate is provided with a filter rib, a first oil return cavity is arranged below the first filter baffle plate, the first filter baffle plate is of a non-closed opening structure, and a first oil return pipe is arranged at the bottom of the first oil return cavity;

the fine separation device is arranged behind the coarse separation device, and the exhaust hole is arranged behind the fine separation device; the exhaust hole is provided with an air outlet pipe connected with a waste gas inlet of the gas-driven oil-gas separator, a compressed gas inlet of the gas-driven oil-gas separator is connected with a supercharging intercooling pipeline on the engine body through an air taking pipe, a mixed gas outlet of the gas-driven oil-gas separator is connected with an air inlet of a gas compressor on the engine body through a vent pipe, and an oil return port of the gas-driven oil-gas separator is connected to an oil pan of the engine body through an oil return header pipe.

2. A natural gas engine with a baffled adaptive ventilation system according to claim 1, wherein: the pre-separation device further comprises a concave baffle, and the concave baffle is further provided with three filtering ribs.

3. A natural gas engine with a baffled adaptive ventilation system according to claim 1, wherein: the material of filter core is any one of non-woven fabrics, felt, glass fiber or synthetic fiber.

4. A natural gas engine with a baffled adaptive ventilation system according to claim 1, wherein: and the first oil return pipe and the second oil return pipe are also provided with umbrella-shaped oil return valves for preventing waste gas from backflushing into the pre-separation device.

5. A natural gas engine with a baffled adaptive ventilation system according to claim 1, wherein: the interval of first filtration orifice board and first baffle of straining is 2 ~ 5mm, the aperture of thick filtration pore is 3 ~ 6mm, the number of thick filtration pore is 10 ~ 45.

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