WO2012034258A1

WO2012034258A1 - Variable-section composite turbine apparatus

Info

Publication number: WO2012034258A1
Application number: PCT/CN2010/001789
Authority: WO
Inventors: 朱智富; 郭晓伟; 王航; 李永泰; 李延昭; 刘功利; 杨国强; 宋丽华
Original assignee: Zhu Zhifu; Guo Xiaowei; Wang Hang; Li Yongtai; Li Yanzhao; Liu Gongli; Yang Guoqiang; Song Lihua
Priority date: 2010-09-14
Filing date: 2010-11-08
Publication date: 2012-03-22
Also published as: CN101985897A

Abstract

A variable-section composite turbine apparatus comprises a double-channel turbine volute (2). The double-channel turbine volute (2) is provided with two air channels. The double-channel turbine volute (2) is provided with a volute air outlet (14) and a volute air inlet (4) communicated with the air channels. A composite turbine impeller (1) is provided in the double-channel turbine volute (2). The composite turbine impeller (1) is a composition of two turbine impellers. The two turbine impellers match with the two air channels respectively. By applying the composite turbine apparatus to enable the variable section, the present invention effectively addresses the deficiencies of poor reliability and high cost of a rotary vane type variable-section supercharger, and can effectively improve the efficiency of the turbine when an engine is at a low speed state and improve the torque output of the turbine.

Description

Variable section composite turbine

Technical field:

The present invention relates to a novel turbo apparatus, and more particularly to a variable cross-section composite turbine apparatus for turbocharging, which can effectively balance the low speed and high speed supercharging requirements of an engine, and belongs to the field of supercharging of internal combustion engines.

Background technique:

With the gradual increase in emission standards, superchargers are widely used in modern engines. In order to meet the performance and emission requirements of all engine operating conditions, especially under low speed conditions, the supercharger must provide higher boost pressure, and has adjustable function of engine intake pressure and exhaust pressure, variable cross section increase Pressureers have become the focus of research and development in the field of pressurization. At present, the structure of adding a rotatable blade at the turbine volute nozzle is generally adopted to meet the requirements of variable cross section, and it can effectively widen the matching range of the turbocharger and the engine compared with the fixed section and the waste bypass type supercharger. , Adjustable function to achieve boost pressure and exhaust pressure.

Schematic diagram of the rotary vane variable section supercharger is shown in Fig. 1. The turbine portion of the rotary vane variable section supercharger includes a turbine volute 20, a volute nozzle 22, and a turbine impeller 24. The exhaust gas from the engine passes through the turbine volute inlet 26 to the volute nozzle 22, and a set of rotatable nozzle vanes 23 are mounted at the nozzle. The transmission mechanism 19 changes the flow area of the nozzle and the outlet flow by controlling the angle of the nozzle vanes 23. Angle, the airflow enters the turbine impeller 24 to work according to the designed angle. The turbine impeller drives the coaxially mounted compressor impeller 29 to rotate at a high speed, compresses the fresh air and sends it into the cylinder to participate in combustion, thereby achieving the purpose of supercharging.

The rotary vane variable section supercharger changes the turbine flow area by changing the angle of the nozzle vanes for easy control. However, such a rotary vane variable turbocharger has been found to have some disadvantages in practical applications. Under large flow conditions, the opening of the nozzle vanes increases, and the trailing edge of the nozzle vanes is away from the leading edge of the turbine vane. More recently, particles in the exhaust gas cause greater wear on the nozzle blades. Under low flow conditions, the nozzle vane opening is small, and the circumferential velocity of the nozzle outlet airflow is high and the radial velocity is low, the turbine inlet angle is large, the turbine becomes a pure impulse turbine, and the turbine efficiency is lowered. On the other hand, the flow cross section at the nozzle changes drastically, and the throttling loss is large, so that the turbine efficiency is further lowered. In addition, the turbocharger works in a harsh environment with high temperature and strong vibration. The overly complicated mechanical structure makes it extremely difficult to improve the reliability and life of the rotary vane variable section supercharger. This leads to high costs and limits the market application of this type of variable section supercharger.

Therefore, it is desirable to design a new variable-section turbine structure with simple structure, low cost, high reliability, and high efficiency and large torque at low flow rate to solve the reliability of the turbocharger of the current rotating blade structure. , cost and efficiency problems, to meet the engine's requirements for boost pressure under various working conditions.

Summary of the invention:

The problem to be solved by the present invention is to provide a variable-section composite turbine device for turbocharging for the above-mentioned drawbacks of the rotary vane variable-section supercharger, which can improve the efficiency and torque of the turbine in the low-speed region of the engine and the turbine rotor. Response characteristics.

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

A variable-section composite turbine device includes a dual-flow turbine volute, wherein the two-flow turbine volute is provided with two air flow passages, and the double-flow turbine volute is provided with a volute air outlet and a worm connected to the air flow passage The shell air inlet is provided with a composite turbine wheel in the double-flow turbine volute. The composite turbine wheel is composed of two turbine impellers, and the two turbine impellers are matched with the two air flow passages one by one.

The following are further improvements to the above solution by the invention:

The turbine wheel includes a primary turbine wheel and a secondary turbine wheel, the primary turbine wheel being secured to an outer rim location of the secondary turbine wheel. Further improvement:

The primary turbine wheel includes a primary turbine inlet portion and a primary turbine intermediate portion; the secondary turbine impeller includes a secondary turbine inlet portion and a secondary turbine intermediate portion, the primary turbine intermediate portion and the secondary turbine inlet portion In addition, the primary turbine wheel and the secondary turbine wheel share a turbine outlet.

Further improvement:

The inlet diameter of the primary turbine wheel is greater than the inlet diameter of the secondary turbine wheel; the inlet width of the primary turbine wheel is less than the inlet width of the secondary turbine wheel.

The inlet width and inlet diameter of the primary and secondary turbine inlets are designed according to the specific performance requirements of the engine. The inlet width and inlet diameter of the primary inlet are designed to meet the performance and emission requirements of the engine at low speeds. The inlet width and inlet diameter of the inlet are matched with the first-stage turbine impeller to meet the performance and emission requirements of the engine at high speeds, and meet the flow capacity requirements of the engine's rated point, avoiding supercharger overspeed and supercharging. The pressure is too high.

Further improvement:

The primary turbine wheel is disposed adjacent one side of the turbine wheel and the secondary turbine wheel is disposed adjacent one side of the turbine rim.

Further improvement: The turbine wheel is a hollow type disk, and the structure can obtain a smaller inertia of the turbine rotor and improve the acceleration response of the turbocharger.

Another improvement: the turbine wheel is a semi-closed wheel. With this configuration, the flow loss caused by the gap at the back of the wheel is reduced, the turbine efficiency is improved, and the strength of the turbine wheel can be improved.

Another improvement:

The air flow passage includes a small flow passage and a large flow passage that cooperate with the primary turbine, and the large flow passage cooperates with the secondary turbine.

Further improvement: The flow area of the small flow passage is smaller than the flow area of the large flow passage, and the outlets of the two flow passages are juxtaposed.

Further improvement:

The outlet of the small flow passage is spaced from the axis of rotation of the turbine by a distance greater than the distance between the outlet of the large flow passage and the axis of rotation of the turbine, and the outlet width of the small flow passage is smaller than the outlet width of the large flow passage.

Further improvement:

An intermediate wall is formed between the small flow passage and the large flow passage, and the intermediate wall is integrally molded with the double flow passage turbine volute.

Further improvement:

The cross-sectional shape of the intermediate wall is a wing shape, the end of the intermediate wall is a linear structure on one side of the large flow passage, and the end of the intermediate wall is curved on the side of the small flow passage.

The thickness of the intermediate wall is determined by the axial length of the intermediate turbine of the composite turbine. When the thickness is large, the weight of the double-flow turbine volute is reduced, material is saved, and excessive stress concentration during temperature change is avoided. The interior can be set to a hollow structure.

Further improvement:

The small flow passage is located on a side away from the vent outlet of the volute, the large flow passage is located on a side close to the air outlet of the volute, the first stage turbine impeller is disposed on a side close to the turbine wheel, and the secondary turbine wheel is disposed adjacent to the turbine One side of the rim.

Another improvement:

The small flow passage is located on a side close to the vent outlet of the volute, the large flow passage is located on a side away from the air outlet of the volute, the first-stage turbine impeller is disposed on a side close to the turbine rim, and the secondary turbine impeller is disposed at Near the side of the turbine wheel.

Further improvement: Airflow guide vanes are provided at the nozzles of the large flow passages, and the airflow guide vanes are obliquely mounted, and the airflow guide vanes are inclined toward the turbine rotation direction to ensure that the airflow enters the turbine at a prescribed angle. The use of this technical solution can improve the efficiency of exhaust gas energy utilization at high speed in the engine, and effectively prevent the backflow generated at the inlet of the secondary turbine from entering the large flow passage when the engine is low speed.

Another improvement:

Air flow guide vanes are provided at the nozzles of the small flow passages, and the air flow guide vanes are obliquely mounted, and the air flow guide vanes are inclined toward the turbine rotation direction to ensure that the air flow flows into the turbine in a prescribed direction. The use of this technical solution can improve the turbine efficiency at low engine speeds and improve the efficiency of exhaust gas energy utilization at low engine speeds.

Another improvement:

Airflow guiding blades are respectively disposed at the nozzles of the small flow passage and the large flow passage, and the airflow guiding blades are obliquely installed, and the airflow guiding blades are inclined to the turbine rotating direction to ensure that the airflow flows into the turbine in a prescribed direction, and the large flow passage The airflow guide vanes at the nozzles effectively prevent backflow from the secondary turbine inlet into the large flow path at low engine speeds. The use of this technical solution can improve the utilization efficiency of exhaust gas energy under most working conditions of the engine, and meet the supercharging requirements of various working conditions of the engine.

The invention realizes the variable cross-section function by using the composite turbine device through the design and development of the turbocharger turbine, and effectively solves the problem that the rotary vane variable-section supercharger has poor reliability and high cost, and can effectively improve the engine low speed. The efficiency of the turbine increases the torque output of the turbine.

At low engine speeds, the engine exhausts less exhaust gas, the intake regulator valve closes, all exhaust gases enter the small flow passage, and the small turbine enters the primary turbine inlet of the composite turbine for work. The small flow passage has a small flow cross-sectional area, which can effectively increase the intake pressure of the turbine volute inlet and increase the energy of the exhaust gas entering the turbine; the first-stage turbine inlet has a smaller intake width and a smaller intake width. The inlet area of the first-stage turbine inlet is small, which can effectively avoid the excessive turbine inlet angle at low engine speed and reduce The intake angle loss of the turbine inlet; the first turbine inlet has a larger inlet diameter, and the higher wheel speed can be obtained under the constant rotation speed, which can effectively avoid the U/C which is too small when the engine is low speed. , to make the turbine work in an efficient area, while using a larger inlet diameter to obtain a larger turbine torque, improve the turbine's ability to do so. Through the increase of turbine intake energy and the increase of turbine efficiency, the energy in the exhaust gas is fully utilized, the power and torque output of the turbine are increased, the supercharging pressure at low engine speed is increased, and excessive exhaust back pressure is avoided. At the same time, due to the small flow passage area of the small flow passage and the large inlet diameter of the first-stage turbine impeller, the acceleration response characteristics of the supercharger can be improved, and the influence of the supercharging hysteresis can be reduced. The inventive composite turbine device can effectively improve engine low speed performance and reduce emissions.

At high engine speeds, the engine exhausts a large amount of exhaust gas, the intake regulator valve opens, and the valve control mechanism controls the opening of the intake regulator valve to properly distribute the gas flow into the large and small flow passages. Due to the different flow capacity of the large and small flow passages, the primary turbine and the secondary turbine have different functions and flow capacities. By changing the proportion of the fluid entering the large and small flow passages, the exhaust pressure of the engine and the power output of the turbine can be effectively adjusted. Meet the performance and emission requirements of the engine under medium and high speed conditions.

The dual-flow turbine volute structure of the invention has little difference from the common two-flow turbine volute structure, has simple structure, good inheritance and high casting yield; the composite turbine impeller of the invention passes the analysis of modern CFD and FEA technologies And optimization can achieve high aerodynamic efficiency and high structural strength; the composite turbine device of the present invention can be produced using existing casting and processing equipment, is low in cost, and can be easily and quickly engineered. The air intake adjustment control mechanism in the present invention is simple, the control method is easy to implement, and the reliability is high.

In summary, the composite turbine device can effectively meet the supercharging requirements of the entire operating range of the engine. The overall structure of the supercharger does not undergo major changes, and there is no need to add new production equipment or modify existing production equipment. Low, easy to implement, with broad marketing value, can achieve good application results.

The present 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 supercharger in the background art of the present invention;

Figure 2 is a schematic structural view of a composite turbine device in Embodiment 1 of the present invention;

3 is a schematic structural view of a meridional flow passage of a composite turbine apparatus according to Embodiment 1 of the present invention; FIG. 4 is a schematic structural view of a composite turbine impeller adopting a hollow type roulette according to Embodiment 1 of the present invention; 1 is a schematic view of a composite turbine wheel structure using a semi-closed disk; FIG. 6 is a schematic view showing a composite turbine structure in Embodiment 2 of the present invention;

Figure 7 is a schematic view showing the structure of a composite turbine in Embodiment 3 of the present invention;

Figure 8 is a schematic view showing the structure of a composite turbine in Embodiment 4 of the present invention;

Figure 9 is a schematic view showing the structure of a composite turbine in Embodiment 5 of the present invention.

In the figure: 1-composite turbine wheel; 2-double-flow turbine volute; 3-intake control valve; 4- volute inlet; 5-stage turbine wheel; 6-stage turbine wheel; 7-small flow 8; large flow passage; 9-stage turbine inlet; 10-stage turbine intermediate; 11-stage turbine inlet; 12-stage turbine intermediate; 13-turbine outlet; Outlet port; 15-intermediate wall; 16-air flow guide vane; 17-compressor casing; 18-middle shell; 19- transmission mechanism; 20-turbine volute; 21-nozzle ring support disc; 22-volute nozzle; - nozzle vane; 24-turbine impeller; 25-volute exhaust port; 26-volute intake runner; 27-floating bearing; 28-turbine rotor shaft; 29 - compressor impeller; 30-opening wheel; - semi-closed wheel; 32-upper housing; 33-connection bolt; 34-lower housing; 35-valve control mechanism; A1-turbine rotation axis; bl--stage turbine impeller inlet width; b2-secondary turbine Inlet inlet width; D1--stage turbine impeller inlet diameter; D2-second turbine impeller inlet diameter.

detailed description:

Embodiment 1, as shown in FIG. 2, a variable-section composite turbine device comprising a dual-flow turbine volute 2, wherein the dual-flow turbine volute 2 is provided with two air flow passages, and the air flow passage includes small Flow The passage 7 and the large flow passage 8, the double-flow turbine volute 2 is provided with a volute air outlet 14 and a volute air inlet 4 communicating with the air flow passage, and a composite turbine impeller 1 is disposed in the double-flow turbine volute 2, The composite turbine impeller 1 is composed of two turbine impellers, and the two turbine impellers are matched with two airflow passages in one-to-one correspondence. The inlet of the dual-flow turbine volute is provided with an air flow regulating valve 3 and a valve control mechanism 35.

As shown in Fig. 3, the turbine wheel includes a first stage turbine wheel 5 and a second stage turbine wheel 6, and the first stage turbine wheel 5 is fixed to the outer edge position of the secondary turbine wheel 6.

The primary turbine wheel 5 includes a primary turbine inlet portion 9 and a primary turbine intermediate portion 10; the secondary turbine impeller 6 includes a secondary turbine inlet portion 11 and a secondary turbine intermediate portion 12, the primary turbine intermediate portion 10 In connection with the secondary turbine inlet portion 11, the primary turbine wheel 5 and the secondary turbine wheel 6 share a turbine outlet portion 13.

The inlet diameter D1 of the primary turbine wheel is greater than the inlet diameter D2 of the secondary turbine wheel; - the inlet width bl of the stage turbine wheel is less than the inlet width b2 of the secondary turbine wheel.

The inlet width and inlet diameter of the primary and secondary turbine inlets are designed according to the specific performance requirements of the engine. The inlet width bl and the inlet diameter D1 of the primary inlet are designed to meet the performance and emission requirements of the engine at low speed. The inlet width b2 and the inlet diameter D2 of the turbine inlet are matched with the first-stage turbine impeller to meet the performance and emission requirements of the engine at high speeds, and meet the flow capacity requirements of the engine rated point, avoiding the supercharger Overspeed and boost pressure are too high.

The large flow path 8 is located on the side close to the vent outlet 14 of the volute, the small flow path 7 is located on the side away from the vent outlet 14 of the volute, and the flow area of the small flow path 7 is smaller than the flow area of the large flow path 8, two flow paths The outlets are juxtaposed, and the distance between the outlet of the small flow passage 7 and the axis of rotation A1 of the turbine is greater than the distance between the outlet of the large flow passage 8 and the axis of rotation A1 of the turbine. The outlet width of the small flow passage 7 is smaller than the outlet width of the large flow passage 8, which is small. The flow passage 7 cooperates with the primary turbine wheel 5, which cooperates with the secondary turbine wheel 6.

The small flow path 7 and the large flow path 8 of the dual-flow turbine volute 2 are reasonably separated by the intermediate wall 15, The intermediate wall 15 is cast in one piece with the double-flow turbine volute 2. The cross-sectional shape of the intermediate wall 15 is a wing shape, the end of the intermediate wall is located on the side of the large flow passage 8 and is linear, and the end of the intermediate wall is located on the side of the small flow passage 7 in an arc shape, and the intermediate portion 10 of the first turbine of the composite turbine impeller The thickness of the intermediate wall is determined by the axial length of the first turbine intermediate portion 10 of the composite turbine. When the thickness is large, the interior of the intermediate wall is a hollow structure.

As shown in Fig. 4, the wheel of the composite turbine wheel 1 can be a hollow type disk 30. With this configuration, a small turbine rotor moment of inertia can be obtained, and the turbocharger's acceleration response characteristic can be improved.

At low engine speeds, the engine exhausts less exhaust gas, the intake regulator valve 3 closes, all exhaust gases enter the small flow passage 7, and the small flow passage 7 enters the primary turbine inlet portion 9 of the composite turbine. The small flow passage 7 has a small flow cross-sectional area, which can effectively increase the intake pressure of the turbine volute inlet and increase the exhaust gas energy entering the turbine; the first-stage turbine inlet portion 9 has a smaller intake air width bl, which is smaller. The intake air width makes the inlet area of the first-stage turbine inlet portion 9 small, which can effectively avoid the excessive turbine inlet angle at low engine speed and reduce the intake angle loss of the turbine inlet; the first-stage turbine inlet portion 9 has a larger The inlet diameter Dl can obtain higher cycle speed under the condition of constant rotation speed, which can effectively avoid U/C which is too small when the engine is low speed, so that the turbine works in an efficient area and at the same time, it can be obtained with a larger inlet diameter. Larger turbine torque increases the turbine's ability to do so. Through the increase of turbine intake energy and the increase of turbine efficiency, the energy in the exhaust gas is fully utilized to increase the power and torque output of the turbine, increase the supercharging pressure at low engine speed and avoid excessive exhaust back pressure. At the same time, since the small flow passage 7 has a small flow area and the first stage turbine has a large inlet diameter D1, the acceleration response characteristic of the turbine can be improved. The composite turbine device can effectively improve engine low speed performance and reduce emissions.

At the high engine speed, the engine exhausts a large amount of exhaust gas, the intake regulator valve 3 is opened, and the valve control mechanism 35 controls the opening degree of the intake regulator valve 3 to reasonably distribute the flow rate of the gas entering the large and small flow passages. Due to the different flow capacity of the large and small runners, the first-stage turbine and the second-stage turbine have different functions and flow capacities. By changing the proportion of fluid entering the large and small flow passages, the exhaust pressure of the engine and the power output of the turbine can be effectively adjusted to meet the performance and emission requirements of the engine under medium and high speed conditions.

The invention patents for the engine to the variable section turbocharger, completes the development of the composite turbine device, adopts the two-stage turbo compounding method, improves the turbine inlet pressure at the low engine speed and improves the turbine efficiency, and improves the efficiency. The engine's low-speed torque and output power improve the engine's acceleration response characteristics while taking into account the engine's low-speed and medium-high-speed conditions. This type of composite turbine unit can be completed using the casting and machining techniques of conventional conventional superchargers.

In the above embodiment 1, as shown in FIG. 5, the wheel of the composite turbine wheel 1 may also be a semi-closed disk 31. With this structure, the flow loss caused by the gap of the back of the wheel is reduced, the turbine Increased efficiency while also increasing the strength of the turbine wheel.

Embodiment 2, as shown in FIG. 6, the present embodiment is different from Embodiment 1 in that the positions of the large flow path 8 and the small flow path 7 of the double flow path volute 2 are interchanged, and one of the composite turbine impellers 1 is The stage turbine wheel 5 is interchanged with the secondary turbine wheel 6 position. At this time, the large flow path 8 is located on the side away from the vent outlet 14 of the volute, the small flow path 7 is located on the side close to the vent outlet 14 of the volute, the first turbine wheel 5 is located on one side of the rim, and the secondary turbine wheel 6 is located on the wheel. One side of the plate.

With this configuration, the flow loss caused by the backlash of the wheel can be eliminated, further improving the efficiency of the first stage turbine at low engine speeds. Since the first turbine inlet diameter D1 is large, for the convenience of installation, the double-flow turbine volute 2 is split-cast, and the double-flow turbine volute is divided into an upper casing 32 and a lower casing 34, respectively, which are cast and sealed. There is machining allowance at the surface. After the sealing surface is machined, the bolts 33 are used to fasten and seal the connection method, and the corresponding supercharger assembly process is adjusted.

The invention patents for the engine to the variable section turbocharger, completes the development of the composite turbine device, adopts the two-stage turbo compounding method, improves the turbine inlet pressure at the low engine speed and improves the turbine efficiency, and improves the efficiency. The low speed torque and output power of the engine improve the engine's acceleration The characteristics should be taken into account, taking into account the boosting demand of the engine under low speed and medium and high speed conditions. This type of composite turbine device can be completed using the casting and processing techniques of conventional conventional superchargers.

In the third embodiment, as shown in Fig. 1, in the first embodiment, the air flow guide vanes 16 may be provided in the nozzles of the large flow passage 8, and the air flow guide vanes 16 may be obliquely installed at the nozzles of the large flow passage 8. The airflow guide vanes 16 are tilted in the direction of turbine rotation to ensure that the airflow enters the turbine at a specified angle. This technical solution can improve the efficiency of exhaust gas energy utilization at high speed in the engine, and effectively prevent the return flow generated at the inlet of the secondary turbine at the low speed of the engine into the large flow passage 8 .

Embodiment 4 As shown in Fig. 8, in the above-described Embodiment 1, it is also possible to provide the air flow guiding vane 16 at the nozzle of the small flow path 7, and the air flow guiding vane 16 is obliquely installed at the nozzle of the small flow path 7. The airflow guide vanes 16 are tilted in the direction of turbine rotation to ensure that the airflow flows into the turbine in a prescribed direction. This technical solution can improve the turbine efficiency at low engine speed and improve the efficiency of exhaust gas energy utilization at low engine speed.

Embodiment 5, as shown in FIG. 9, in the above Embodiment 1, it is also possible to arrange the air flow guiding blades 16 at the nozzles of the large flow path 8 and the small flow path 7, and the air flow guiding blades 16 are obliquely mounted on the large flow path 8 and At the nozzle of the small flow path 7. The airflow guide vanes 16 are tilted in the direction of rotation of the turbine to ensure that the airflow flows into the turbine in a prescribed direction. The airflow guide vanes at the nozzles of the large flow passages 8 are effective to prevent backflow from the secondary turbine inlets into the large flow passages 8 at low engine speeds. The use of this technical solution can improve the utilization efficiency of exhaust gas energy under most working conditions of the engine, and meet the supercharging requirements of various working conditions of the engine.

The invention patents for the engine to the variable section turbocharger, completed the development of the composite turbine device, and adopted the two-stage turbo compounding method, which improved the turbine intake pressure at the low engine speed and improved the turbine efficiency, and improved the efficiency. The engine's low-speed torque and output power improve the engine's acceleration response characteristics while taking into account the engine's low-speed and medium-high-speed conditions. This type of composite turbine device can be completed by the casting and processing techniques of conventional conventional superchargers.

Claims

Rights request

A variable-section composite turbine device comprising a dual-flow turbine volute (2), the dual-flow turbine volute (2) having two air flow passages, and a dual-flow turbine volute (2) a volute air outlet (14) and a volute air inlet (4) communicating with the air flow passage, and a composite turbine impeller (1) in the dual flow turbine volute (2), characterized in that the composite turbine impeller (1) It is composed of two turbine impellers, and the two turbine impellers are matched with the two airflow passages one by one.

2. The variable cross-section composite turbine apparatus according to claim 1, wherein: said turbine wheel comprises a first stage turbine wheel (5) and a second stage turbine wheel (6), said first stage turbine wheel (5) Secured to the outer edge of the secondary turbine wheel (6).

The variable-section composite turbine device according to claim 2, characterized in that: the first-stage turbine impeller (5) comprises a first-stage turbine inlet portion (9) and a first-stage turbine intermediate portion (10); The turbine wheel (6) includes a secondary turbine inlet (11) and a secondary turbine intermediate portion (12), the primary turbine intermediate portion (10) being fixed to the secondary turbine inlet portion (11), a primary turbine impeller (5) and secondary turbine impeller

(6) Share one turbine outlet (13).

The variable-section composite turbine device according to claim 2 or 3, characterized in that: the primary turbine wheel (5) is disposed near the side of the turbine wheel, and the secondary turbine wheel (6) is disposed close to Turbine rim side.

The variable-section composite turbine apparatus according to claim 4, wherein the scroll wheel is a hollow type disk (30).

The variable-section composite turbine apparatus according to claim 4, wherein: the turbine wheel is a semi-closed disk (31).

The variable-section composite turbine device according to claim 2, wherein: the air flow passage comprises a small flow passage (7) and a large flow passage (8), and the small flow passage (7) and the first passage The turbine (5) is matched, The large runner (8) is matched to the secondary turbine (6).

The variable-section composite turbine device according to claim 7, characterized in that: the outlet of the small flow passage (7) is at a greater distance from the turbine rotation axis (A1) than the outlet and turbine of the large flow passage (8) The distance from the axis of rotation (A1), the outlet width of the small flow passage (7) is smaller than the outlet width of the large flow passage (8).

The variable-section composite turbine device according to claim 8, characterized in that: between the small flow passage (7) and the large flow passage (8), an intermediate wall (15) is provided, the intermediate wall ( 15) integrally molded with the double-flow turbine volute (2), the intermediate wall (15) has a cross-sectional shape of a wing shape, and the end of the intermediate wall is located at the large flow passage (8) - the side is a straight line structure, and the end of the intermediate wall is small The flow path (7) - the side is an arc structure.

10. The variable cross-section composite turbine device according to claim 9, wherein: the small flow passage (7) is located on a side away from the volute air outlet (14), and the large flow passage (8) is located near the volute On one side of the port (14), the primary turbine wheel (5) is disposed on a side adjacent the turbine wheel and the secondary turbine wheel (6) is disposed on a side adjacent the turbine rim.

The variable-section composite turbine device according to claim 10, characterized in that: the small flow passage (7) is located on a side close to the volute air outlet (14), and the large flow passage (8) is located away from the volute On one side of the casing outlet (14), the primary turbine wheel (5) is disposed on a side adjacent the turbine rim, and the secondary turbine wheel (6) is disposed on a side adjacent the turbine wheel.

The variable-section composite turbine apparatus according to claim 11, characterized in that: at the nozzle of the large flow passage (8), air flow guiding vanes (16) are provided, and the air flow guiding vanes (16) are installed obliquely.

The variable-section composite turbine device according to claim 11, characterized in that: the nozzle of the small flow path (7) is provided with an air flow guiding blade (16), and the air flow guiding blade (16) is installed obliquely.

The variable-section composite turbine device according to claim 11, characterized in that: at the nozzles of the small flow passage (7) and the large flow passage (8), air flow guiding blades (16) are respectively provided, the air flow The guide vanes (16) are mounted obliquely.