WO2012094781A1

WO2012094781A1 - Axial-radial-flow composite turbocharger with a variable section

Info

Publication number: WO2012094781A1
Application number: PCT/CN2011/000459
Authority: WO
Inventors: 王航; 刘莹; 李永泰; 朱智富; 宋丽华
Original assignee: Wang Hang; Liu Ying; Li Yongtai; Zhu Zhifu; Song Lihua
Priority date: 2011-01-12
Filing date: 2011-03-23
Publication date: 2012-07-19
Also published as: CN102080578B; CN102080578A

Abstract

An axial-radial-flow composite turbocharger with variable sections includes a dual-flow passage turbine housing (10) provided with an axial-flow passage (11) and a radial-flow passage (12). The axial-flow passage and the radial-flow passage are respectively provided with a turbine housing nozzle (5) that communicates with a turbine housing air outlet barrel (24). A sliding slot is arranged on the dual-flow passage turbine housing near the turbine housing nozzle of the radial-flow passage. A slidable moving throat mouth baffle (17) is arranged in the sliding slot. The moving throat mouth baffle is connected with a moving throat mouth baffle control mechanism in a transmission manner. The turbocharger can realize a variable section function, reduce the cost of the blade-type turbocharger with variable sections, and effectively improve the turbine efficiency when the engine is at low speeds

Description

Variable section shaft runoff compound turbocharger

Technical field:

The present invention relates to a turbocharger, and more particularly to a variable-section axial-diameter composite turbocharger, which can effectively balance the high and low-speed supercharging requirements of an engine, and belongs to the field of internal combustion engines. Background technique:

Superchargers are widely used in modern engines. To meet the performance and emissions requirements of the engine under all operating conditions, the supercharger must have an adjustable function of boost pressure and discharge pressure. With the implementation of the national four-discharge regulations, the variable-section supercharger and the two-stage supercharger have become the focus of research and development in the domestic and foreign industries.

At present, the rotary vane is installed at the volute nozzle to meet the requirements of the variable cross section. Compared with the conventional supercharger, it can effectively widen the matching range between the supercharger and the engine, and realize the booster pressure of the supercharger. And the regulation of the discharge pressure.

Schematic diagram of the rotary vane variable-section turbocharger is shown in Fig. 1. The turbine portion of the rotary vane variable-section turbocharger includes a volute 3, a volute nozzle 5, and a turbine impeller 7. The transmission mechanism 2 adjusts the flow area of the nozzle and the angle of the outlet exhaust gas by adjusting the opening degree of the nozzle vane 6 mounted on the nozzle ring support disk 4, so that the high-temperature exhaust gas is blown toward the turbine impeller 7 according to the designed air flow angle, and the turbine impeller 7 is pushed. High speed rotation. The rotor shaft 8 drives the compressor impeller 9 in the compressor casing 1 to rotate at a high speed to compress the air entering the compressor axially, and the compressed air is sent to the cylinder through the collection of the compressor casing for combustion.

The rotary vane variable section supercharger can adjust the opening angle of the nozzle vane 6 in real time according to different operating conditions of the engine to change the flow area of the volute nozzle to meet the performance requirements of the engine. The adjustment of the nozzle vane 6 by the transmission mechanism 2 is simple and easy to control. However, in practical applications, the rotary vane variable section turbocharger has been found to have some disadvantages:

When the engine is under high flow conditions, the nozzle vanes 6 are closer to the leading edge of the turbine blade, and the exhaust particles are Great wear is caused to the nozzle vanes 6. When the engine is under low flow conditions, the nozzle vane 6 is far from the leading edge of the turbine blade. At this time, the circumferential velocity of the high-temperature airflow is large, the turbine becomes an impulsive turbine, and the aerodynamic loss during the gas flow is also serious. The efficiency of the supercharger is reduced.

The exhaust temperature of the engine is about 650~850 °C, and there is a tendency to increase further. The working condition of the turbocharger is harsh, and the strong vibration has high requirements on the reliability of the transmission mechanism 2. The problem of poor reliability of the transmission mechanism 2 has not been well solved.

The high cost of the rotary vane variable section supercharger has made many engine manufacturers prohibit their expensive prices. Cost and longevity also limit the market for this type of variable section supercharger.

The secondary supercharging uses a low-pressure turbocharger and a high-pressure turbocharger to work together to achieve engine boosting. For details, please refer to the publication number CN 101600869 A. The invention is a two-stage supercharged exhaust turbocharger. The use of two-stage boosting is actually a combination of two superchargers with different sizes and characteristics. The turbine is equipped with two different volutes and turbines, which are variable flow passage sections and two flow characteristics turbines. Supercharger, which can achieve higher boost ratio, high reliability and low boost ratio of each stage of turbocharger, so that single-stage compressor has a wide high efficiency area, but the main disadvantage is The matching, the control is complicated, the space size is large, and the cost is high.

Summary of the invention:

The problem to be solved by the present invention is to provide a simple structure and low cost for the high cost, low speed efficiency, poor reliability, and complicated structure and high cost of the rotary vane variable area turbocharger. A variable-section composite turbine device with high reliability and high efficiency at low flow rates while taking into account the efficiency and flow characteristics of large flow conditions.

In order to solve the above problems, the present invention adopts the following technical solutions:

A variable-section axial-diameter composite turbocharger device comprises a double-flow volute, an axial flow passage and a radial flow passage are arranged on the double-flow volute, and the axial flow path and the radial flow path are respectively provided with a volute Shell pump a communicating volute nozzle, wherein the double-fluid volute is provided with a sliding slot at a position of the volute nozzle near the radial flow passage, and a slidable moving throat flap is arranged in the sliding slot, and the moving throat baffle drive connection is provided There is a moving throat flap control mechanism.

The following is a further improvement of the above solution by the present invention:

The radial flow channel is located on a side close to the volute air outlet cylinder, the axial flow flow channel is located on a side away from the volute air outlet cylinder, and an intermediate wall is disposed between the radial flow flow passage and the axial flow flow passage.

Further improvement:

The moving throat baffle control mechanism includes an actuator, and a fork ring is sleeved on the outside of the volute air outlet cylinder, the moving throat baffle is fixedly connected with the fork ring, and the actuator is mounted on the actuator A shifting fork is connected between the rod, the actuator push rod and the fork ring.

The moving throat baffle control mechanism realizes the opening and closing of the radial flow passage by controlling the axial movement of the moving throat baffle, and ensures that the gas does not enter the radial flow volute flow path when the axial flow turbine is operated, thereby further improving the eddy current loss. :

A dual turbine volute is provided with a composite turbine wheel, and the composite turbine wheel includes a first stage turbine wheel and a second stage turbine wheel.

The primary turbine blades and the secondary turbine impeller blades may be set to different numbers depending on the performance requirements of the supercharger and the requirements for matching the engine to meet engine performance requirements and emission requirements.

Further improvement:

The first stage turbine wheel is composed of straight blades, the secondary turbine wheel is composed of turbine centripetal blades, the first stage turbine wheel is matched with the axial flow path, and the secondary turbine wheel is matched with the radial flow path.

Further improvement:

a partition plate is installed in the radial flow channel, and the partition plate divides the radial flow channel into two flow channels, and the axial flow channel shape Into three intake runners.

Another improvement:

Separators are installed in the axial flow path and the radial flow path, and the axial flow path and the radial flow path are respectively divided into two flow paths.

The baffle plate can make better use of the pulse energy of the exhaust gas, so that the pulse wave propagates in a small space, the pulse energy attenuation is reduced, the efficiency of the turbine is improved, and the problem of insufficient pressurization of the engine at a low speed is improved to some extent, and at the same time effective It takes into account the efficiency of the engine's large flow conditions and reduces engine emissions.

Further improvement:

A guide vane is mounted at the volute nozzle of the axial flow passage, and the guide vane is tilted toward the first turbine wheel to control the turbine intake angle to improve turbine efficiency.

Another improvement:

The first-stage turbine impeller is spaced apart from the secondary turbine impeller with a gap therebetween, and an annular cavity is disposed at a position corresponding to the gap on the intermediate wall, and a stationary vane is uniformly installed in the annular cavity. The stationary vanes are located between the primary turbine wheel and the secondary turbine wheel.

The provision of static vanes can reduce the flow disturbance of the primary turbine impeller and the secondary turbine impeller flow to a certain extent, and reduce the energy loss of the gas in the impeller.

The axial flow turbine has a small single-stage expansion ratio, low intake loss and high efficiency, while the radial turbine has a large single-stage expansion ratio but low efficiency.

The invention adopts a double-flow volute composed of an axial flow passage and a radial flow passage to work sequentially with a composite turbine impeller composed of a first-stage turbine impeller and a secondary turbine impeller, which satisfies the performance requirements of the engine under low speed and small load. It can meet the large flow capacity of the engine and make the turbine have greater circulation capacity and higher efficiency.

Axial flow turbines have a wide flow range, axial turbines have high efficiency at high flow rates, radial turbines The flow range is narrow, but it is more efficient in the small flow range. After the composite turbine is used, the composite turbine can ensure that the supercharger can have higher efficiency under small flow and large flow, and meet the working requirements of various working conditions of the engine.

When the engine is under low flow conditions, the axial flow passage intake valve is closed, the radial flow passage intake valve is opened, and at this time, the moving throat flap is driven to the side of the intermediate wall by the moving throat flap control mechanism. Move to move the throat guard in the open state. The exhaust gas from the engine only works on the secondary turbine impeller through the radial flow passage. Since the radial turbine has high efficiency at a small flow rate, it can meet the supercharging requirements of the engine at low speed and small load. To widen the flow range of the radial turbine, a larger turbine diameter is required. When the shaft-run multi-composite turbine is used, the diameter of the turbine can be reduced as a whole, the turbine structure can be made more compact, and the responsiveness of the supercharger can be improved. The effect of pressure hysteresis.

When the engine is under high flow conditions, the radial flow inlet valve is closed, the axial flow inlet valve is opened, and the moving throat stop is moved toward the middle wall side by the moving throat flap control mechanism. , the moving throat baffle is closed, to ensure that the axial flow channel works, the gas does not enter the radial flow channel, reducing the turbine flow loss. The exhaust gas from the engine only works through the axial flow passage to the first-stage turbine impeller, the turbine intake loss is reduced, the axial flow turbine has a wide flow range, and the high efficiency at high flow rate can satisfy the engine under large flow conditions. The turbine has a large flow capacity and a high efficiency.

The dual-flow turbine volute of the invention has simple structure, good inheritance and high casting yield; the composite turbine impeller of the invention can obtain higher aerodynamic efficiency and higher by analyzing and optimizing modern CFD and FEA technologies. Structural strength; The variable-section composite turbine device of the present invention can be produced by using existing casting and processing equipment, and is low in cost and easy to be quickly and engineered.

The invention adopts the composite turbine device to realize the variable cross-section function, and effectively solves the high cost, low-speed efficiency, low reliability, complicated structure and high cost of the blade type variable-section turbocharger. The problem is to effectively improve the efficiency of the turbine at low engine speeds, while effectively balancing the efficiency of the engine at high flow conditions.

The invention will be further described below in conjunction with the accompanying drawings and embodiments:

BRIEF DESCRIPTION OF THE DRAWINGS:

1 is a schematic structural view of a rotary vane variable-section turbocharger in the background art of the present invention; FIG. 2 is a schematic structural view of a variable-section composite turbine device according to Embodiment 1 of the present invention; A schematic structural view of an intake valve control mechanism in Embodiment 1 of the present invention;

Figure 4 is a schematic view showing the structure of a variable-section composite turbine device in a small flow condition in Embodiment 1 of the present invention;

Figure 5 is a schematic view showing the structure of a variable-section composite turbine device in a large flow condition in Embodiment 1 of the present invention;

Figure 6 is a schematic structural view of Embodiment 2 of the present invention;

Figure 7 is a schematic structural view of Embodiment 3 of the present invention;

Figure 8 is a schematic structural view of Embodiment 4 of the present invention;

Figure 9 is a schematic structural view of Embodiment 5 of the present invention;

Figure 10 is a schematic structural view of Embodiment 6 of the present invention;

Figure 11 is a schematic view showing the structure of Embodiment 7 of the present invention.

In the figure: 1-compressor casing; 2-transmission mechanism; 3-volute; 4-nozzle ring support plate; 5-volute nozzle; 6-nozzle blade; 7-turbine wheel; 8-rotor shaft; Machine impeller; 10-double flow volute; 1 1 - axial flow passage; 12-runoff flow passage; 13-composite turbine wheel; 14-stage turbine wheel; 15-stage turbine wheel; 】 6-intermediate wall; 17-moving throat baffle; 18-actuator; 19-actuator push rod; 20-switch fork; 21-fork ring; 22-actuator bracket; 23-fixed shaft; 24-volute outlet tube; Axial flow passage intake valve; 26- radial flow inlet valve; 27-intake valve control mechanism; 28-separator; 29-flow guide cascade; 30-static vane Film.

detailed description:

Embodiment 1 As shown in FIG. 2 and FIG. 3, a variable-section axial-diameter composite turbocharger includes a dual-flow volute 10, and a composite turbine wheel 13 and a rotor shaft are disposed in the dual-flow volute 10. 8; the double-flow volute 10 is connected with a volute air outlet 24; the double-flow volute 10 is provided with an axial flow passage 11 and a radial flow passage 12, wherein the axial flow passage 11 and the radial flow passage 12 respectively A volute nozzle 5 is provided in communication with the volute air outlet 24.

The radial flow channel 12 is located on a side close to the volute air outlet 24, the axial flow channel 11 is located on a side away from the volute air outlet tube 24, and an intermediate wall is disposed between the radial flow channel 12 and the axial flow channel 11 16.

The radial flow passage 12 is provided with a radial flow passage intake valve 26, and the axial flow passage 11 is provided with an axial flow passage intake valve 25, the radial flow passage intake valve 26 and the axial flow passage intake valve 25 The intake valve control mechanism 27 is respectively connected to the intake valve control mechanism 27, and the intake valve control mechanism 27 realizes the axial flow passage 11 and the radial flow passage 12 by controlling the opening and closing of the axial flow passage intake valve 25 and the radial flow passage intake valve 26. The sequence of the engine under different flow conditions.

The composite turbine wheel 13 includes a primary turbine wheel 14 and a secondary turbine wheel 15, wherein the primary turbine wheel 14 is comprised of straight blades and the secondary turbine wheel 15 is comprised of turbine radial blades, a primary turbine wheel 14 and axial flow. The flow passages 11 cooperate, and the secondary turbine impeller 15 cooperates with the radial flow passage 12.

A sliding slot is disposed on the double-flow volute 10 near the volute nozzle 5 of the radial flow passage 12, and a slidable moving throat flap 17 is disposed in the sliding slot, and the moving throat flap 17 is connected by a drive Move the throat flap control mechanism.

The moving throat flap control mechanism includes an actuator 18 that is fixedly supported by the actuator bracket 22 on the dual flow volute 10.

A fork ring 21 is sleeved on the outside of the volute air outlet 24, and the moving throat flap 17 and the fork ring 21 fixed connection.

An actuator push rod 19 is mounted on the actuator 18, and a shift fork 20 is connected between the actuator push rod 19 and the fork ring 21, and the fork end 20-terminal is fixedly connected with the fork ring 21, and the other end is connected with the actuator The push rod 19 is fixedly connected by a rotating shaft, and the intermediate portion of the shift fork 20 is rotatably coupled to the actuator bracket 22 via a fixed rotating shaft 23.

As shown in FIG. 3 and FIG. 4, under low flow conditions, the intake valve control mechanism 27 controls the axial flow passage intake valve 25 to close, the radial flow passage intake valve 26 opens, and the throat is moved at this time. The port shutter 17 is moved back to the intermediate wall 16 side by the moving throat flap control mechanism, so that the moving throat flap 17 is in an open state.

Exhaust gas from the engine only works through the radial flow passage 12 to the secondary turbine impeller 15. Since the radial turbine has high efficiency at a small flow rate, it can meet the supercharging requirements of the engine at low speed and small load. And with the shaft-run-flow composite turbine, the diameter of the turbine can be reduced as a whole, the turbine structure can be made more compact, the responsiveness of the supercharger can be improved, and the effect of boost hysteresis can be reduced.

As shown in FIG. 3 and FIG. 5, the engine is under high flow conditions, the intake valve control mechanism 27 regulates the radial flow passage intake valve 26 to close, the axial flow passage intake valve 25 is opened, and the throat is moved at this time. The port baffle 17 is moved toward the side of the intermediate wall 16 by the moving throat baffle control mechanism, so that the moving throat baffle 17 is in a closed state, so as to ensure that the gas does not enter the radial flow path when the axial flow path is operated. Reduce the flow loss of the turbine. The exhaust gas from the engine only passes through the axial flow channel. 1 The first-stage turbine impeller 14 works, the turbine intake loss is reduced, the axial flow turbine has a wide flow range, and the high flow rate has high efficiency, which can satisfy the engine at a large flow rate. The turbine has a larger flow capacity and higher efficiency under working conditions.

The invention patents the development of a variable-section composite turbine device for an engine with a variable-section turbocharger, and adopts a two-stage turbo compounding method to improve the turbine efficiency at a low engine speed. It also improves the engine's low-speed torque and output power, improves the engine's acceleration response characteristics, and at the same time takes into account the engine's low-speed and medium-high-speed conditions. This type of variable-section composite turbine device can be completed by the casting and processing techniques of conventional conventional superchargers.

In the above embodiment, the volute air outlet 24 can also be made movable. The engine can adjust the axial position of the volute air outlet 24 under a small flow condition to meet the flow capacity of the radial flow turbine. Good match under flow conditions.

Embodiment 2: As shown in FIG. 6, in order to utilize the pulse energy reasonably, a spacer 28 may be separately installed in the axial flow path 11 and the radial flow path 12 on the basis of Embodiment 1, and the axial flow is performed. The track 11 and the radial flow path 12 are each divided into two flow paths.

The partition 28 is integrally molded with the double flow volute 10. The intake manifold is installed in each of the four flow inlets divided by the partition 28, and the intake valve control mechanism controls the opening and closing of each intake valve to rationally utilize the exhaust pulse energy.

After adopting this technical scheme, the pulse energy of the exhaust gas can be better utilized, the pulse wave propagates in a small space, the pulse energy attenuation is reduced, the efficiency of the turbine is improved, and the problem of insufficient boosting of the engine at a low speed is improved to some extent. At the same time, it can effectively balance the flow capacity of the turbine with large flow conditions and improve the efficiency of the turbine.

Embodiment 3, as shown in FIG. 7, in order to utilize the pulse energy reasonably, on the basis of Embodiment 1, only the partition 28 is installed in the radial flow passage 12, and the partition 28 divides the radial flow passage 12 into two. The flow passages form three intake flow passages with the axial flow passage 1 1 , and the intake valves are respectively installed in the three intake flow passages of the dual flow passage volute, and the opening and closing of the intake valves are controlled by the intake valve control mechanism. Meet the performance requirements of the engine under various working conditions.

Under the small flow condition, after the diaphragm 28 is installed in the radial flow channel 12, the pulse energy of the exhaust gas can be effectively utilized, the efficiency of the turbine can be improved, and the problem of insufficient low-speed supercharging of the engine can be improved. Under large flow conditions, the axial flow turbine has a wide flow range and high efficiency, which can meet the turbine's turbine flow capacity under high flow conditions. Moreover, compared with the second embodiment, an intake valve control mechanism is used less in the axial flow passage, so that the structure of the composite turbine device is simplified, and the operation is easier to realize.

Embodiment 4: As shown in FIG. 8, on the basis of Embodiment 1, a guide vane 29 can be installed at the position of the volute nozzle 5 of the axial flow passage 11, and the guide vane 29 is directed to the first-stage turbine impeller. 14 The direction of rotation is inclined to ensure that the airflow is blown into the primary turbine wheel 14 in a prescribed direction. The use of this technical solution can improve the profit of the exhaust gas energy of the axial flow passage 11 at the medium and high speeds, improve the turbine efficiency, and meet the requirements of the engine large flow conditions.

Embodiment 5: On the basis of Embodiment 2, as shown in FIG. 9, a guide vane 29 is mounted at the position of the volute nozzle 5 of the axial flow passage 11, and the guide vane 29 is directed to the first-stage turbine impeller 14. The direction of rotation is inclined to ensure that the airflow is blown into the primary turbine wheel 14 in a prescribed direction.

The use of this technical solution can improve the utilization of the exhaust gas energy of the axial flow passage 11 at the medium and high speeds, improve the turbine efficiency, and meet the requirements of the engine large flow conditions.

Embodiment 6: As shown in FIG. 10, the first-stage turbine impeller 14 and the secondary turbine impeller 15 can also be designed as two separate parts on the basis of the embodiment 5, without connecting them together, the two impellers There is a certain gap therebetween, and an annular cavity is arranged on the intermediate wall 16 corresponding to the gap, and a stationary vane 30 is uniformly installed in the annular cavity, and the static vane 30 is located in the first stage turbine impeller 14 and two. Within the gap between the stage turbine impellers 15.

Under high engine flow conditions, the gas that works on the primary turbine wheel 14 is reduced to flow into the secondary turbine impeller 15 under engine low flow conditions. The gas that reduces the work on the secondary turbine wheel 15 flows into the first-stage turbine impeller 14, which reduces the flow disturbance of the airflow in the impeller to a certain extent, and reduces the energy loss of the gas in the impeller.

The stationary vane 30 has a certain clearance in the radial direction from the rotor shaft hub to ensure the first stage turbine impeller M The secondary turbine wheel can rotate normally without getting stuck to the stationary blade 30, and the stationary blade 30 is fixed by bolts to meet the structural strength requirement of the double-flow volute 10.

Embodiment 7: As shown in FIG. 11, the first stage turbine impeller 14 and the secondary turbine wheel 15 may be designed as separate two parts on the basis of the embodiment 3, without being connected together, the two impellers There is a certain gap therebetween, and an annular cavity is arranged on the intermediate wall 16 corresponding to the gap, and a stationary vane 30 is uniformly installed in the annular cavity, and the static vane 30 is located in the first stage turbine impeller 14 and two. Within the gap between the stage turbine impellers 15.

Under the condition of large engine flow, the gas for reducing the work of the first-stage turbine wheel 14 is reduced to flow into the second-stage turbine wheel 15, and under the small-flow condition of the engine, the gas for reducing the work of the second-stage turbine wheel 15 is reduced to flow into the first-stage turbine wheel 14, To some extent, the flow disturbance of the airflow in the impeller is reduced, and the energy loss of the gas in the impeller is reduced.

The invention claims the development of a variable-section composite turbocharger for an engine with a variable-section turbocharger, and adopts a two-stage turbo compounding method to improve the turbine efficiency at a low engine speed and improve the low speed of the engine. Torque and output power improve the engine's acceleration response while taking into account the boosting requirements of the engine at low and medium speeds. This type of variable-section composite turbine unit can be completed using the casting and machining techniques of conventional conventional superchargers.

We have now described the invention in detail in accordance with the National Patent Law, and those skilled in the art will recognize improvements or substitutions to the specific embodiments disclosed herein. These modifications are within the spirit and scope of the present invention.

Claims

Rights request

1. A variable section axial runoff composite turbocharger comprising a dual flow volute (10), the dual flow volute (10) having an axial flow passage (11) and a radial flow passage (12), The axial flow passage (11) and the radial flow passage (12) are respectively provided with a volute nozzle (5) communicating with the volute air outlet cylinder (24), wherein: the double flow passage volute (10) is close to The volute nozzle (5) of the radial flow passage (12) is provided with a chute, and a slidable moving throat baffle (17) is arranged in the chute, and the moving throat baffle (17) is connected by a transmission connection. Throat baffle control mechanism.

2. The variable section axial flow compound turbocharger according to claim 1, wherein: the radial flow passage (12) is located on a side close to the volute air outlet (24), and the axial flow passage (11) ) is located on a side away from the volute air outlet (24), and an intermediate wall (16) is disposed between the radial flow passage (12) and the axial flow passage (11).

3. The variable section axial runoff compound turbocharger according to claim 2, wherein: said moving throat baffle control mechanism comprises an actuator (18), an outer sleeve of the volute air outlet (24) A shifting fork ring (21) is attached, the moving throat baffle (17) is fixedly connected with the fork ring (21), and the actuator (18) is mounted with an actuator push rod (19), and the actuator pushes A shift fork (20) is connected between the rod (19) and the fork ring (21).

4. The variable section axial flow compound turbocharger according to claim 3, wherein: the dual flow volute (10) is provided with a composite turbine wheel (13), and the composite turbine wheel (13) comprises Primary turbine wheel (14) and secondary turbine wheel (15).

5. The variable section axial runoff compound turbocharger according to claim 4, wherein: said first stage turbine wheel (14) consists of straight blades, and the secondary turbine wheel (15) consists of turbine centering blades. The first stage turbine wheel (14) cooperates with the axial flow passage (11) and the secondary turbine wheel (15) cooperates with the radial flow passage (12).

6. The variable-section axial-diameter composite turbocharger according to claim 5, wherein: the radial flow passage (12) is provided with a partition (28), and the partition (28) is a radial flow passage. (12) Divided into two flow paths, forming three intake flow paths with the axial flow path (11).

The variable-section axial-diameter composite turbocharger according to claim 5, wherein: a spacer (28) is mounted in the axial flow passage (11) and the radial flow passage (12), respectively The flow channel (11) and the radial flow channel (12) are each divided into two flow channels.

The variable-section axial-diameter composite turbocharger according to claim 5, wherein: the guide vane (29) is mounted at a position of the volute nozzle (5) of the axial flow passage (11), The cascade (29) is inclined toward the direction of rotation of the primary turbine wheel (14).

The variable-section axial-diameter composite turbocharger according to any one of claims 6 or 7, wherein a guide vane is installed at a position of a volute nozzle (5) of the axial flow passage (11). The grid (29), the guide vane (29) is inclined toward the direction of rotation of the primary turbine wheel (14).

The variable-section axial-diameter composite turbocharger according to claim 9, wherein: the first-stage turbine wheel (14) is spaced apart from the secondary turbine wheel (15) with a gap therebetween An annular cavity is disposed on the intermediate wall (16) corresponding to the gap, and a stationary vane (30) is uniformly installed in the annular cavity, and the static vane (30) is located in the first-stage turbine impeller (14) Between the secondary turbine wheel (15) and the secondary turbine.