Closed-circuit breathing apparatus

Abstract

The application discloses a closed breathing device, which belongs to the technical field of diesel engines and is used for connecting multiple sets of superchargers of a diesel engine. The multiple sets of superchargers include a first supercharger and a second supercharger. The closed breathing device includes multiple oil-gas separators, which are divided into a first group and a second group. The oil-gas separators in the first group are communicated with the first supercharger through first connecting pipes, and the oil-gas separators in the second group are communicated with the second supercharger through second connecting pipes. By dividing the multiple oil-gas separators into two groups with different numbers, different numbers of oil-gas separators can be put into operation under different operating conditions of the diesel engine, the system flow area can be self-adaptively adjusted according to the operating conditions, and therefore, the crankcase pressure of the large-power sequential supercharged diesel engine under full operating conditions can be stably controlled within a reasonable range, and the reliable operation of the diesel engine is ensured.

Description

Technical Field

[0001] This application relates to the field of diesel engine technology, and more particularly to a closed-type breathing apparatus. Background Technology

[0002] Diesel engine breather devices can be classified into open and closed types according to the system circulation mode. With the continuous upgrading of emission regulations, the adoption of closed breather devices in diesel engines has become a development trend, and it is currently widely used in small and medium power vehicle and engineering engines in China.

[0003] However, for high-power diesel engines, especially those using sequential turbocharging systems, as engine power increases, piston blow-by also increases, leading to greater crankcase pressure and its fluctuation range. Excessive crankcase pressure negatively impacts the sealing of crankcase components and the lubrication of the crankshaft end oil seals, while insufficient crankcase pressure causes excessive intake of high-temperature volatile components from the crankcase oil into the turbocharger, resulting in over-contamination of the intake system. In high-power diesel engines with a fixed flow area, increased oil mist velocity leads to reduced separation efficiency and shortened filter life. Summary of the Invention

[0004] This application provides a closed-type breather device, which aims to solve the technical problem that when the flow area is fixed, the increased oil mist velocity in a high-power diesel engine leads to reduced separation efficiency and shortened filter element life.

[0005] To achieve the above objectives, this application provides a closed-loop breathing apparatus for connecting multiple sets of turbochargers to a diesel engine, the multiple sets of turbochargers including a first turbocharger and a second turbocharger, the closed-loop breathing apparatus comprising: Multiple oil-gas separators, which are divided into a first group and a second group. The oil-gas separator in the first group is connected to the first turbocharger via a first connecting pipe, and the oil-gas separator in the second group is connected to the second turbocharger via a second connecting pipe.

[0006] In some embodiments, the first connecting pipe connects all of the oil-gas separators in the first group to the first booster; The number of the second connecting pipes is the same as the number of the oil-gas separators in the second group, and each of the oil-gas separators in the second group is connected to the second booster through one of the second connecting pipes.

[0007] In some embodiments, the first connecting pipe has a first connection port and a plurality of second connection ports, the first connection port being connected to the first booster, the number of the second connection ports being the same as the number of the oil-gas separators in the first group, and each of the oil-gas separators in the first group being connected to one of the second connection ports.

[0008] In some embodiments, the number of oil-gas separators in the second group is multiple, and the second booster has multiple interfaces, each of which is connected to a second connecting pipe.

[0009] In some embodiments, there are multiple first groups, first boosters and first connecting pipes, and all the oil-gas separators in each first group are connected to the first booster through one of the first connecting pipes. And / or, there are multiple second groups and multiple second boosters, and all the oil-gas separators in each second group are connected to one of the second boosters.

[0010] In some embodiments, the oil-gas separator includes: The outer casing has a communicating receiving cavity and an air outlet; An air outlet pipe is disposed inside the outer casing and communicates with the air outlet. A throttling sleeve is sleeved on the outlet pipe, and an air inlet is provided on the throttling sleeve, which is connected to the outlet pipe; The throttling sleeve can adjust the communication area between the air inlet and the air outlet.

[0011] In some embodiments, the throttling sleeve is detachably connected to the air outlet pipe. The throttling sleeve has a circumferential wall and a side wall. The side wall is connected to one end of the circumferential wall, and the air inlet is provided on the circumferential wall.

[0012] In some embodiments, the throttling sleeve is movably fitted onto the outlet pipe, and the throttling sleeve can move along the extension direction of the outlet pipe to adjust the communication area between the inlet and the outlet pipe.

[0013] In some embodiments, the closed-loop respirator device further includes: A distribution box, on which the plurality of oil-gas separators are mounted; The return oil pipe has one end connected to the distribution box and the other end connected to the gearbox.

[0014] In some embodiments, the closed-loop respirator device further includes: A venting box having a connected processing chamber and an opening, the distribution box cover sealing the opening, and the processing chamber communicating with the oil-gas separator; The filter screen is stacked and spaced apart within the processing chamber. Each filter screen has multiple filter holes, and the spacing between the filter holes in each filter screen is different.

[0015] In some embodiments, on a plane perpendicular to the stacking direction of the multiple layers of filter screens, the orthographic projections of the filter pores on adjacent layers of filter screens are staggered.

[0016] In some embodiments, the closed respirator device further includes a support connected to the side of the ventilation box opposite to the dispensing box; The ventilation box has a ventilation pipe and an air inlet pipe connected on the side opposite to the distribution box, and the extension direction of the ventilation pipe is inclined relative to the vertical direction.

[0017] In some embodiments, the second booster is positioned relative to the first booster and close to the plurality of oil-gas separators; The first connecting pipe includes a manifold section, a first flexible hose section, a straight hose section, and a second flexible hose section. The first flexible hose section connects the manifold section and the straight hose section respectively. The second flexible hose section is connected to the end of the straight hose section away from the first flexible hose section. The manifold section has a plurality of second communication ports, and the second flexible hose section has the first communication port.

[0018] The closed-loop breather device in this embodiment is used to connect multiple turbochargers of a diesel engine. The multiple turbochargers include a first turbocharger and a second turbocharger. The closed-loop breather device includes multiple oil-gas separators, which are divided into a first group and a second group. The oil-gas separators in the first group are connected to the first turbocharger via a first connecting pipe, and the oil-gas separators in the second group are connected to the second turbocharger via a second connecting pipe. By dividing the multiple oil-gas separators into different numbers of first and second groups, and connecting the oil-gas separators in the first group to the first turbocharger via the first connecting pipe and the oil-gas separators in the second group to the second turbocharger via the second connecting pipe, different numbers of oil-gas separators can be activated under different operating conditions of the diesel engine. This allows the system flow area to adaptively adjust with changes in operating conditions, thereby stably controlling the crankcase pressure of the high-power sequentially turbocharged diesel engine within a reasonable range under all operating conditions, ensuring reliable operation of the diesel engine.

[0019] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0022] Figure 1 This is a schematic diagram showing the connection relationship between the closed respirator device and multiple sets of boosters according to an embodiment of this application; Figure 2 This is a three-dimensional structural schematic diagram of the closed respirator device according to an embodiment of this application; Figure 3 This is a cross-sectional schematic diagram of the oil-gas separator in the closed-loop respirator device of this application embodiment; Figure 4 This is a three-dimensional structural schematic diagram of the throttling sleeve in the closed respirator device according to an embodiment of this application; Figure 5 This is an exploded schematic diagram of the ventilation box and distribution box in the closed respirator device of this application embodiment, which shows the multi-layer filter screen.

[0023] Explanation of reference numerals in the attached figures: 101. First turbocharger; 102. Second turbocharger; 200. Oil-gas separator; 210. First group; 220. Second group; 300. First connecting pipe; 400. Second connecting pipe; 301. First connecting port; 302. Second connecting port; 103. Interface; 201. Outer shell; 202. Receiving cavity; 203. Air outlet; 204. Air outlet pipe; 500. Throttling sleeve; 501. Air inlet; 502. Circumferential wall; 503. Side wall; 600. Distribution box; 700. Oil return pipe; 800. Vent box; 801. Processing chamber; 802. Opening; 803. Filter screen; 804. Support; 805. Vent pipe; 806. Air inlet pipe; 310. Manifold section; 320. First hose section; 330. Straight pipe section; 340. Second hose section. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0025] In the description of this application, the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In the description of this application, "multiple" means two or more, and "at least one" can refer to one, two, or more, unless otherwise explicitly specified. The terms "first," "second," and "third," etc., are merely for the convenience of description and are used to name components or embodiments by number. They do not imply any order of importance between the components or embodiments.

[0026] Diesel engine breather devices can be classified into open and closed types according to the system circulation mode. With the continuous upgrading of emission regulations, the adoption of closed breather devices in diesel engines has become a development trend, and it is currently widely used in small and medium power vehicle and engineering engines in China.

[0027] However, for high-power diesel engines, especially those using sequential turbocharging systems, as engine power increases, piston blow-by increases, and crankcase pressure and its fluctuation range also increase. Excessive crankcase pressure negatively impacts the sealing of crankcase components and the lubrication of crankshaft end oil seals, while insufficient crankcase pressure allows excessive high-temperature volatile components of the crankcase oil to be drawn into the turbocharger, leading to excessive contamination of the intake system and problems such as air cooler blockage. Currently, it is difficult to control crankcase pressure within a reasonable range. On the other hand, with increased diesel engine power, crankcase oil mist concentration increases, and the breather's operating flow rate increases. With a fixed flow area, the increased oil mist velocity within the breather reduces the breather's oil-gas separation efficiency, shortens the lifespan of the breather filter element, and increases diesel engine maintenance costs.

[0028] In view of the above, this application provides a closed respirator device, which aims to solve at least one of the above-mentioned technical problems.

[0029] Please see Figure 1 and Figure 2This application provides a closed-loop breather device for connecting multiple turbochargers of a diesel engine. The multiple turbochargers include a first turbocharger 101 and a second turbocharger 102. The first turbocharger 101 is the turbocharger that operates during engine startup and low-operation conditions, while the second turbocharger 102 operates sequentially as the engine's operating conditions rise to medium and high operating conditions. Therefore, the closed-loop breather device of this application is particularly suitable for high-power diesel engines employing a sequential turbocharging system. The closed-loop breather device includes multiple oil-gas separators 200, divided into a first group 210 and a second group 220. The oil-gas separators 200 in the first group 210 are connected to the first turbocharger 101 via a first connecting pipe 300, and the oil-gas separators 200 in the second group 220 are connected to the second turbocharger 102 via a second connecting pipe 400. In this way, by dividing multiple oil-gas separators 200 into a first group 210 and a second group 220, and connecting the two groups of oil-gas separators 200 to turbochargers that are put into operation under different operating conditions, different numbers of oil-gas separators 200 can be put into operation under different operating conditions of the diesel engine. This allows the flow area of ​​the closed breather device to be adaptively adjusted according to the changes in operating conditions, thereby stabilizing and controlling the crankcase pressure of the high-power sequential turbocharged diesel engine within a reasonable range under all operating conditions, ensuring the reliable operation of the diesel engine.

[0030] Specifically, in this embodiment, there are ten oil-gas separators 200, with the first group 210 including six oil-gas separators 200 and the second group 220 including four oil-gas separators 200. Further, there are two first turbochargers 101. The six oil-gas separators 200 in the first group 210 are divided into two groups of three, and each group is connected to one of the two first turbochargers 101 via two first connecting pipes 300. There are two second turbochargers 102. The four oil-gas separators 200 in the second group 220 are divided into two groups of two, and each group is connected to one of the two second turbochargers 102. In other words, there are multiple first groups 210, multiple first turbochargers 101 and multiple first connecting pipes 300. All oil-gas separators 200 in each first group 210 are connected to the corresponding first turbocharger 101 through a first connecting pipe 300. Similarly, there are multiple second groups 220 and multiple second turbochargers 102. All oil-gas separators 200 in each second group 220 are connected to a second turbocharger 102.

[0031] Of course, in other embodiments, the total number of oil-gas separators 200, the ratio between the first group 210 and the second group 220, and the specific number of turbochargers and connecting pipes can be adaptively adjusted according to the power level of the diesel engine, the amount of piston blow-by, and the arrangement of the turbochargers. This application does not make specific limitations in this regard.

[0032] That is, in another embodiment, the number of oil-gas separators 200 is four, wherein the first group 210 includes three oil-gas separators 200 and the second group 220 includes one oil-gas separator 200. The number of first boosters 101 is one, and the number of second boosters 102 is one. The three oil-gas separators 200 in the first group 210 are all connected to the first booster 101 through a first connecting pipe 300. The first connecting pipe 300 has a first connecting port 301 and three second connecting ports 302. The first connecting port 301 is connected to the air inlet bend of the first booster 101, and the three second connecting ports 302 are respectively connected to the air outlets 203 of the three oil-gas separators 200. The oil-gas separator 200 in the second group 220 is connected to the second booster 102 through a second connecting pipe 400. This embodiment is applicable to high-power diesel engines with relatively small piston blow-by volume. During startup and low operating conditions, only the first turbocharger 101 is in operation, and the three oil-gas separators 200 provide a flow area matching the blow-by volume under low operating conditions. When the diesel engine operating conditions rise to medium and high operating conditions, the second turbocharger 102 is put into operation in succession, and the oil-gas separators 200 in the second group 220 are put into operation accordingly. The system flow area is moderately increased, which can also stably control the crankcase pressure of the high-power sequentially turbocharged diesel engine within a reasonable range under all operating conditions. Moreover, compared with the embodiment with ten oil-gas separators 200, the number of oil-gas separators 200 is less, the structure is more compact, and the cost is lower.

[0033] In another embodiment, there are eight oil-gas separators 200, with a first group 210 comprising five oil-gas separators 200 and a second group 220 comprising three oil-gas separators 200. There is one first booster 101 and one second booster 102. The five oil-gas separators 200 in the first group 210 are all connected to the first booster 101 via a first connecting pipe 300. The first connecting pipe 300 has five second connecting ports 302 on its confluence section 310, and each of the five second connecting ports 302 is connected to the outlet 203 of the five oil-gas separators 200 respectively. The three oil-gas separators 200 in the second group 220 are connected to the three ports 103 of the second booster 102 respectively via three second connecting pipes 400. This embodiment is applicable to high-power diesel engines with moderate piston blow-by volume. While ensuring stable control of crankcase pressure under all operating conditions, it reduces the number of oil-gas separators 200, thereby reducing the space occupied and maintenance costs of the device.

[0034] Please see Figure 2 and Figure 5The closed-loop breather device also includes a vent box 800, a distribution box 600, a bracket 804, and a return oil pipe 700. The bracket 804 is fixed to the diesel engine block by connecting bolts, and the vent box 800 is supported and fixed to the bracket 804, thus reliably fixing the entire closed-loop breather device to the top of the engine block. An intake pipe 806 is connected to the side of the vent box 800 opposite to the distribution box 600. The lower end of the intake pipe 806 is connected to a vent hole on the engine block. Oil mist gas in the crankcase enters the vent box 800 through the vent hole and intake pipe 806 under pressure differential. The distribution box 600 is sealed at the opening 802 of the vent box 800. Multiple oil-gas separators 200 are installed on the distribution box 600. Gas that has undergone pre-separation and filtration in the vent box 800 enters the distribution box 600 and is distributed to each oil-gas separator 200. One end of the return oil pipe 700 is connected to the distribution box 600, and the other end is connected to the gearbox of the diesel engine. Specifically, the threaded surface of the top pipe joint of the return oil pipe 700 is threadedly connected and fixed to the return oil hole at the bottom of the distribution box 600, and the threaded surface of the bottom pipe joint of the return oil pipe 700 is threadedly connected and fixed to the gearbox. The lubricating oil separated by the oil-gas separator 200 is collected by the distribution box 600 and flows to the gearbox through the return oil pipe 700, and finally flows back to the oil pan, realizing the recovery and circulation of lubricating oil. Thus, crankcase oil mist enters the closed breather device from the engine vent, and after multi-stage separation, the clean gas enters the turbocharger intake system to participate in secondary combustion, while the separated lubricating oil returns to the oil pan through the return oil path, without communicating with the atmosphere throughout the process, forming a complete closed-loop circulation circuit.

[0035] Please see Figure 1 and Figure 2The first connecting pipe 300 has a first connecting port 301 and a plurality of second connecting ports 302. The first connecting port 301 is connected to the first booster 101. The number of second connecting ports 302 is the same as the number of oil-gas separators 200 in the first group 210, and each oil-gas separator 200 in the first group 210 is connected to one second connecting port 302. In this embodiment, the first connecting pipe 300 includes a manifold section 310, a first hose section 320, a straight pipe section 330, and a second hose section 340. The first hose section 320 is connected to the manifold section 310 and the straight pipe section 330, respectively. The second hose section 340 is connected to the end of the straight pipe section 330 away from the first hose section 320. The manifold section 310 has a plurality of second connecting ports 302, and the second hose section 340 has a first connecting port 301. During assembly, the inner circular surfaces of the positioning ports 302 of the manifold 310 are respectively fitted onto the outer circular surfaces of the corresponding air outlets 203 of the oil-gas separators 200, and secured with clamps to achieve parallel connection between the manifold 310 and the three oil-gas separators 200 in the same group. The downstream end of the manifold 310 is connected to the intake bend of the first turbocharger 101 via bolts through the first hose section 320, the straight pipe section 330, and the second hose section 340. Among them, the manifold 310 and the straight pipe section 330 are rigid pipes. The straight pipe section 330 is a relatively long rigid straight pipe, which can ensure the structural rigidity of the pipeline when bridging the first turbocharger 101 which is far away. The first hose section 320 and the second hose section 340 are breathable hoses, which can absorb the vibration displacement and installation deviation during the operation of the diesel engine and avoid damage to the pipeline due to stress.

[0036] Please continue reading. Figure 1 In this embodiment, the second group 220 contains multiple oil-gas separators 200, and the second booster 102 has multiple interfaces 103, each of which is connected to a second connecting pipe 400. The number of second connecting pipes 400 is the same as the number of oil-gas separators 200 in the second group 220, and each oil-gas separator 200 in the second group 220 is connected to the second booster 102 through a second connecting pipe 400. Specifically, taking two oil-gas separators 200 connected to each second booster 102 as an example, each second booster 102 has two interfaces 103, and the air outlets 203 of the two oil-gas separators 200 are respectively connected to the two interfaces 103 one-to-one through their respective second connecting pipes 400. The second connecting pipe 400 is a breathable flexible hose, and its two ends are respectively connected and fixed to the air outlets 203 of the oil-gas separators 200 and the air inlet bends of the second booster 102 by clamps, which facilitates disassembly and maintenance.

[0037] Furthermore, the second booster 102 is positioned relatively close to the first booster 101 and near the multiple oil-gas separators 200. Since the second booster 102 is closer to the closed-circuit breathing apparatus, a shorter flexible hose can be used for direct connection. However, the first booster 101 is farther from the closed-circuit breathing apparatus, so a first connecting pipe 300 with a straight section 330 is used for bridging, ensuring flow capacity while maintaining structural reliability for long-distance pipeline arrangements. Simultaneously, the two rows of pipelines corresponding to the two first boosters 101 are arranged separately, avoiding interference between pipelines and facilitating individual disassembly, assembly, and maintenance of each oil-gas separator 200.

[0038] Please see Figure 3 The oil-gas separator 200 includes a housing 201, which has a communicating receiving cavity 202 and an outlet 203. In this embodiment, the oil-gas separator 200 is a filter-type oil-gas separator. A filter element is provided inside the receiving cavity 202, and the filter element is replaceably installed inside the receiving cavity 202 so that it can be replaced and maintained periodically when it reaches the end of its service life. When the oil mist gas entering the receiving cavity 202 flows through the filter element, the fine oil droplets carried in the gas are captured by the filter element and converge into an oil film. Under the action of gravity, the oil film slides down the inner wall of the housing 201 to the bottom of the receiving cavity 202, achieving deep separation of oil and gas. The outlet 203 is formed at the top of the housing 201 and is used to output the separated clean gas to the first connecting pipe 300 or the second connecting pipe 400. The bottom of the oil-gas separator 200 is also provided with an oil return hole, through which the separated lubricating oil flows downward into the distribution box 600. The parallel arrangement of multiple oil-gas separators 200 also makes it easier to replace and maintain only the corresponding oil-gas separator 200 when a certain filter element reaches the end of its service life, thus reducing the amount of maintenance work.

[0039] The oil-gas separator 200 also includes an outlet pipe 204 and a throttling sleeve 500. The outlet pipe 204 is located at the outlet end of the outer casing 201 and communicates with the outlet port 203. The throttling sleeve 500 is fitted onto the outlet pipe 204 and has an inlet port 501 that communicates with the outlet pipe 204. The throttling sleeve 500 can adjust the communication area between the inlet port 501 and the outlet pipe 204. Please refer to [link / reference]. Figure 4The throttling sleeve 500 has a circumferential wall 502 and a side wall 503. The side wall 503 is connected to one end of the circumferential wall 502. An air inlet 501 is provided on the circumferential wall 502. The throttling sleeve 500 is supported and sleeved on the outside of the air outlet pipe 204 by the side wall 503. After being filtered by the filter element, the gas in the receiving cavity 202 enters the flow channel between the throttling sleeve 500 and the air outlet pipe 204 through the air inlet 501 on the circumferential wall 502, and then exits the oil-gas separator 200 through the air outlet pipe 204 and the air outlet 203. Therefore, the size of the communication area between the air inlet 501 and the air outlet pipe 204 directly determines the flow resistance at the outlet of the oil-gas separator 200.

[0040] The specific structural form of the outer casing 201 may include a casing body and an end cap, which together form a receiving cavity 202. The vent pipe 204 may be provided on the end cap, and the vent 203 is also formed on the end cap.

[0041] In this embodiment, the throttling sleeve 500 is detachably connected to the outlet pipe 204. On one hand, throttling sleeves 500 with different fixed-distance heights can be replaced. The fixed-distance height refers to the axial height or position of the air inlet 501 on the throttling sleeve 500 (i.e., the direction of fluid flow). By replacing throttling sleeves 500 with different fixed-distance heights, the communication area between the air inlet 501 and the outlet pipe 204 is changed, thereby altering the flow resistance and back pressure at the outlet of the oil-gas separator 200. On the other hand, the throttling sleeve 500 can also be movably fitted onto the outlet pipe 204, and the throttling sleeve 500 can move along the extension direction of the outlet pipe 204. For example, the throttling sleeve 500 can be driven to move axially along the outlet pipe 204 via electronic control to adjust the communication area between the air inlet 501 and the outlet pipe 204, thus achieving electronically controlled adjustment of the fixed-distance height of the throttling sleeve 500. When the throttle sleeve 500 moves along the outlet pipe 204, the overlapping area between the air inlet 501 on the circumferential wall 502 and the airflow channel of the outlet pipe 204 increases or decreases accordingly, and the connecting area changes accordingly, thereby continuously and steplessly adjusting the outlet resistance of the oil-gas separator 200, and then, in conjunction with the suction effect on the turbocharger side, precisely controlling the crankcase pressure within the target range.

[0042] Please see Figure 2 and Figure 5The venting box 800 has a connected processing chamber 801 and an opening 802. The distribution box 600 covers the opening 802, and the processing chamber 801 is connected to the oil-gas separator 200. The closed-circuit respirator also includes a multi-layer filter screen 803, which is stacked and spaced apart in the processing chamber 801. Each layer of filter screen 803 has multiple filter holes, and the spacing between the filter holes in each layer of filter screen 803 is different. In this embodiment, the multi-layer filter screen 803 is a metal filter screen, and there are three layers of filter screen 803. The spacing between the filter holes in the three layers of filter screen 803 is different, that is, each layer of filter screen 803 is designed with different filter hole positioning distances. Each layer of filter screen 803 is designed with staggered filter holes. Each layer of filter screen 803 is fixed to the mounting surface of the venting box 800 by bolts, and adjacent layers of filter screen 803 are maintained at a predetermined interval by a spacer. On a plane perpendicular to the stacking direction of the multi-layer filter screen 803, the orthographic projections of the filter holes on adjacent filter screens 803 are staggered, so that the flow channel of oil mist gas passing through the multi-layer filter screen 803 from bottom to top is in a stacked and staggered form with multiple turns, which prolongs the flow path of oil mist gas in the processing chamber 801 and increases the probability of collision and capture of oil droplets with filter screen 803.

[0043] During assembly, first press the outer circular surface of the intake pipe 806 into the mounting hole of its lower intake pipe 806 flange until the positioning surface of the intake pipe 806 contacts and fits against the positioning surface of the mounting hole. An O-ring installed in the sealing groove of the mounting hole of the intake pipe 806 flange is used to seal the lower positioning outer circular surface of the intake pipe 806. The intake pipe 806 flange is fixed to the machine body with bolts, and the hole of the intake pipe flange communicates with the vent hole on the machine body. Then, press the positioning inner circular surface of the vent box 800 into the upper positioning outer circular surface of the intake pipe 806. An O-ring installed in the sealing groove of the positioning inner circular surface of the vent box 800 is used to seal the two cylindrical mating surfaces. The upper flange mounting surface of the vent pipe 805 is locked and sealed to the lower vent mounting surface of the vent box 800 by gaskets and bolts. The lower flange mounting surface of the vent pipe 805 is fixed to the vent mounting surface of the top of the machine body by bolts. The two mounting surfaces are sealed with sealant. The extension direction of the vent pipe 805 is inclined relative to the vertical direction. On the one hand, it facilitates the downward flow of oil. On the other hand, it avoids other components above the machine body and reduces the flow resistance of the airflow. The multi-layer filter screen 803 is stacked and spaced in the treatment chamber 801 of the venting box 800. Bolts are inserted into the mounting through holes of the venting box 800 and tightened to the bracket 804 to ensure that the positioning end face of the venting box 800 is fitted with the positioning upper end face of the bracket 804. The two mounting end faces are sealed with an O-ring in the sealing groove on the positioning end face of the bracket 804. Finally, the positioning lower plane of the distribution box 600 is fitted with the positioning upper plane of the venting box 800 and tightened with bolts and washers. The two mounting planes are sealed with sealant. Connect and fix the threaded surface of the top pipe joint of the return oil pipe 700 to the return oil hole at the bottom of the distribution box 600, and connect and fix the threaded surface of the bottom pipe joint to the gearbox; then install and fit the lower positioning plane of the oil-gas separator 200 with the pre-installed throttling sleeve 500 to the upper positioning plane of the distribution box 600, and tighten and fix it with bolts and washers. This completes the assembly of the entire closed-type breather device. After the assembly is completed, all mating surfaces form a reliable seal, ensuring the airtightness of the device.

[0044] The basic working principle of the closed-loop breather device in this application embodiment is as follows: When the high-power sequential turbocharged diesel engine is running, the oil mist gas in the crankcase enters the closed-loop breather device through the vent on the engine block under the action of pressure difference. The oil mist gas first flows along the cavity walls of the intake pipe 806 and the vent pipe 805. Larger oil droplets in the oil mist collide with the pipe walls under the action of inertia, completing the first-stage oil-gas pre-separation. Subsequently, the oil mist gas enters the processing chamber 801 of the vent box 800. The oil mist with a certain flow velocity collidees with the multi-layer filter screen 803 in a stacked and interlaced manner under the action of flow inertia. Due to the density difference between the oil droplets and the gas, the larger oil droplets are adsorbed on the filter screen 803 and precipitate on the inner wall of the vent box 800 under the action of gravity, and collect in the lower part of the processing chamber 801, completing the second-stage oil-gas separation. The collected lubricating oil flows back to the oil pan through the intake pipe 806, the top hole of the engine block, and the engine block cavity. Smaller oil droplets that remain with the gas flow after secondary separation enter the various oil-gas separators 200 via the distribution box 600. There, the filter elements in the receiving chamber 202 perform tertiary oil-gas separation. The filtered clean gas then enters the turbocharger's intake bend through the exhaust pipe 204, the exhaust port 203, and the corresponding first connecting pipe 300 or second connecting pipe 400, ultimately entering the diesel engine combustion chamber for secondary combustion, achieving a closed-loop cycle and reducing pollution caused by crankcase oil mist directly entering the atmosphere. The lubricating oil separated in the tertiary stage flows into the distribution box 600 through the oil return hole of the oil-gas separator 200, then flows to the gearbox via the return pipe 700, and finally returns to the oil pan. This multi-stage oil-gas separation design improves the oil-gas separation efficiency of the closed-loop breather device under high oil mist concentration conditions, extends the service life of the oil-gas filter elements, and reduces the lubricating oil consumption rate and maintenance costs of the diesel engine.

[0045] It should be noted that, with a fixed flow area, as the diesel engine power increases, the crankcase oil mist concentration increases, the breather's working flow rate increases, and the oil mist velocity within the breather increases accordingly. Excessively high oil mist velocities reduce oil-gas separation efficiency and shorten the lifespan of the oil-gas filter element. This embodiment connects the second group 220 of oil-gas separators 200 to the subsequently operational second turbocharger 102, automatically increasing the system's flow area under medium and high operating conditions. This ensures that the number of operating oil-gas separators 200 matches the amount of oil mist in the crankcase, controlling the oil mist velocity within a single oil-gas separator 200 at a reasonable level. This maintains high oil-gas separation efficiency even under high oil mist concentration conditions, extends the lifespan of the oil-gas filter element, and reduces diesel engine maintenance costs.

[0046] Furthermore, considering the sequential turbocharging characteristics of high-power diesel engines, the closed-loop breather device regulates crankcase pressure as follows: During diesel engine startup and low-operation operation, only the first turbocharger 101 is operational. At this time, both the turbocharger intake vacuum and crankcase pressure are low, resulting in low oil mist concentration within the crankcase. Through the arrangement of the breather pipe 805, the oil-gas separator 200 of the first group 210 operates under the suction effect of the first turbocharger 101 intake vacuum, meeting the requirements for controlling crankcase pressure under low operating conditions. When the diesel engine operates at medium or high operating conditions, the piston blow-by volume increases with the increase in engine power, leading to a corresponding increase in the amount and concentration of oil mist generated in the crankcase. The second turbocharger 102 then engages, and the second set of oil-gas separators 200 (220) also engages under the suction effect of the intake vacuum of the second turbocharger 102. The number of oil-gas separators 200 in operation increases accordingly, and the flow area also increases, thereby controlling the rate of change of oil mist flow rate and achieving a pressure stabilization effect. On the other hand, by electronically adjusting the fixed-distance height of the throttling sleeve 500 pre-installed in the oil-gas separator 200, or by replacing it with a throttling sleeve 500 designed with different fixed-distance heights, the connection area between the intake port 501 and the outlet pipe 204 is changed, thereby altering the flow resistance and back pressure at the outlet of the oil-gas separator 200, and controlling the crankcase pressure within a reasonable range of slightly normal pressure under all operating conditions. This avoids the adverse effects of excessive crankcase pressure on crankcase component sealing and crankshaft end oil seal lubrication, while also preventing excessively low crankcase pressure from causing high-temperature volatile components of the crankcase lubricating oil to be excessively drawn into the turbocharger and excessively contaminate the intake system, leading to air cooler blockage. This ensures the reliable operation of the diesel engine.

[0047] In summary, the closed-loop breather device of this application divides multiple oil-gas separators 200 into a first group 210 and a second group 220 with different numbers of separators, and connects them to the first turbocharger 101 and the second turbocharger 102 operating under different conditions in the sequential turbocharging system, so that the system flow area can be adaptively adjusted according to the diesel engine operating conditions. At the same time, the throttle sleeve 500 adjusts the connection area between the air inlet 501 and the air outlet pipe 204, changing the flow resistance and back pressure at the outlet of the oil-gas separator 200. The two work together to stably control the crankcase pressure of the high-power sequential turbocharged diesel engine under all operating conditions within a reasonable range. Furthermore, through the multi-stage oil-gas separation structure design consisting of the collision pre-separation of the air inlet pipe 806 and the breather pipe 805, the overlapping and interlacing interception of the multi-layer filter screen 803, and the deep filtration of the filter element oil-gas separator 200, the oil-gas separation efficiency is effectively improved under high oil mist concentration conditions, the lubricating oil consumption rate is reduced, the service life of the oil-gas filter element is extended, and the maintenance cost of the diesel engine is reduced. Meanwhile, the closed-loop structure introduces crankcase oil mist into the intake system for secondary combustion, which, compared to the environmental pollution caused by the direct release of hydrocarbons and particulate matter from crankcase oil mist into the atmosphere by open-loop breathers, meets increasingly stringent emission regulations.

[0048] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0049] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0050] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A closed-loop respirator device, characterized in that, Multiple turbochargers for connecting a diesel engine, the multiple turbochargers including a first turbocharger (101) and a second turbocharger (102), the closed-type breather device including: Multiple oil-gas separators (200) are divided into a first group (210) and a second group (220). The oil-gas separators (200) in the first group (210) are connected to the first booster (101) through a first connecting pipe (300), and the oil-gas separators (200) in the second group (220) are connected to the second booster (102) through a second connecting pipe (400).

2. The closed-loop respirator device according to claim 1, characterized in that, The first connecting pipe (300) connects all the oil-gas separators (200) in the first group (210) to the first booster (101). The number of the second connecting pipes (400) is the same as the number of the oil-gas separators (200) in the second group (220), and each of the oil-gas separators (200) in the second group (220) is connected to the second booster (102) through one of the second connecting pipes (400).

3. The closed-loop respirator device according to claim 2, characterized in that, The first connecting pipe (300) has a first connecting port (301) and a plurality of second connecting ports (302). The first connecting port (301) is connected to the first booster (101). The number of the second connecting ports (302) is the same as the number of the oil-gas separators (200) in the first group (210), and each of the oil-gas separators (200) in the first group (210) is connected to one of the second connecting ports (302).

4. The closed-loop respirator device according to claim 2, characterized in that, The number of oil-gas separators (200) in the second group (220) is multiple, and the second booster (102) has multiple ports (103), each of which is connected to a second connecting pipe (400).

5. The closed-loop respirator device according to claim 2, characterized in that, There are multiple first groups (210), first boosters (101) and first connecting pipes (300), and all the oil-gas separators (200) in each first group (210) are connected to the first booster (101) through one first connecting pipe (300); And / or, there are multiple second groups (220) and multiple second boosters (102), and all the oil-gas separators (200) in each second group (220) are connected to an interface (103) of one of the second boosters (102).

6. The closed-loop respirator device according to claim 1, characterized in that, The oil-gas separator (200) includes: The outer casing (201) has a communicating receiving cavity (202) and an air outlet (203). An exhaust pipe (204) is disposed inside the outer casing (201) and communicates with the exhaust port (203); A throttling sleeve (500) is sleeved on the air outlet pipe (204). An air inlet (501) is provided on the throttling sleeve (500) and the air inlet (501) is connected to the air outlet pipe (204). The throttling sleeve (500) can adjust the communication area between the air inlet (501) and the air outlet (204).

7. The closed-loop respirator device according to claim 6, characterized in that, The throttling sleeve (500) is detachably connected to the air outlet pipe (204). The throttling sleeve (500) has a circumferential wall (502) and a side wall (503). The side wall (503) is connected to one end of the circumferential wall (502). The air inlet (501) is provided on the circumferential wall (502).

8. The closed-loop respirator device according to claim 7, characterized in that, The throttling sleeve (500) is movably sleeved on the air outlet pipe (204). The throttling sleeve (500) can move along the extension direction of the air outlet pipe (204) to adjust the communication area between the air inlet (501) and the air outlet pipe (204).

9. The closed-loop respirator device according to claim 1, characterized in that, The closed respirator device also includes: Distribution box (600), on which the plurality of oil-gas separators (200) are disposed; The oil return pipe (700) is connected at one end to the distribution box (600) and at the other end to the gearbox.

10. The closed-loop respirator device according to claim 9, characterized in that, The closed respirator device also includes: A venting box (800) has a connected processing chamber (801) and an opening (802), the distribution box (600) covers the opening (802), and the processing chamber (801) is connected to the oil-gas separator (200); A multi-layer filter (803) is stacked and spaced apart in the processing chamber (801). Each layer of the filter (803) has multiple filter holes, and the spacing between the filter holes in each layer of the filter (803) is different.

11. The closed-loop respirator device according to claim 10, characterized in that, On a plane perpendicular to the stacking direction of the multiple layers of filter screens (803), the orthographic projections of the filter holes on two adjacent layers of filter screens (803) are staggered.

12. The closed-loop respirator device according to claim 10, characterized in that, The closed respirator device also includes a support (804) connected to the side of the ventilation box (800) opposite to the dispensing box (600); The ventilation box (800) has a ventilation pipe (805) and an air inlet pipe (806) connected on the side away from the distribution box (600), and the extension direction of the ventilation pipe (805) is inclined relative to the vertical direction.

13. The closed-loop respirator device according to claim 3, characterized in that, The second booster (102) is positioned relative to the first booster (101) and close to the plurality of oil-gas separators (200); The first connecting pipe (300) includes a manifold section (310), a first flexible hose section (320), a straight hose section (330), and a second flexible hose section (340). The first flexible hose section (320) is connected to the manifold section (310) and the straight hose section (330), respectively. The second flexible hose section (340) is connected to the end of the straight hose section (330) away from the first flexible hose section (320). The manifold section (310) has a plurality of second communication ports (302), and the second flexible hose section (340) has a first communication port (301).

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