JPH05256149A - Turbine structure of turbo-compound engine - Google Patents

Abstract

PURPOSE:To provide an engine with a turbocharger formed into such structure that plural turbines are disposed coaxially and assembled integrally and that all the turbines act smoothly even at the lowered time of exhaust gas. CONSTITUTION:A double flow turbine shaft 4 is provided with a generator 8 and a compressor C, and an axial flow turbine 12 and a generator 18 rotated by this turbine 12 are provided coaxially with the double flow turbine shaft 4 so as to feed gas, discharged from a double flow turbine, to the axial flow turbine 12. A slide shutter 14 for throttling inlet area is provided at the inlet 13 of the axial flow turbine 12. An intake by-pass 26 is provided between the inlet and outlet of the compressor C, and the inlet is provided with a change- over shutter 27 for performing change-over between a compressor passage and the by-pass passage. Even when the exhaust gas flow is small, the inlet area is adjusted by the slide shutter 14 to perform the efficient operation of the axial flow turbine 12, and when exhaust gas is a small quantity, the inlet is closed by the change-over shutter 27 to stop the action of the compressor C, thus performing power generation of high efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a turbocharger attached to an engine, and more particularly to a structure of a turbocharger capable of effectively recovering exhaust energy.

[0002]

2. Description of the Related Art A turbine is driven by utilizing energy contained in exhaust gas of an internal combustion engine, air is compressed by a compressor linked to the turbine, and the compressed air is supercharged into a cylinder to improve efficiency. It has been a long time since a turbocharger that burns fuel physically has been installed in an internal combustion engine.

It is also well known that a large amount of energy still remains in the exhaust gas discharged from the turbocharger turbine. Therefore, when the rotary shaft of the rotary electric machine is connected to the rotary shaft that connects the turbine and the compressor, and when a large amount of energy in the exhaust gas remains, the compressor not only compresses the air but also rotates it. A system in which an electric machine is caused to act as a generator and energy recovered by a turbine can be recovered also as electric energy is disclosed in JP-A-62-263333 and the like, and is known. Even in such a system, since a large amount of energy still remains in the exhaust gas discharged from the turbine, another turbine is connected in series downstream of the turbine and the rotary shaft of the turbine is connected. A system has also been developed in which a generator is connected to and the exhaust energy from this generator is converted into electrical energy and recovered.

[0004]

By the way, since the two turbines of the system for converting the exhaust energy into electric energy and recovering the same are radial turbines (convective turbines), these two turbines are structurally separated from each other. It is not possible to combine them on one axis and arrange them integrally. For this reason 2
Two turbines are individually arranged on the side of the internal combustion engine, and the two turbines are connected by a pipe, and the gas input direction of the turbine and the gas discharge direction of the turbine are different.
When trying to align the rotation axes of two turbines in the same direction, quite unreasonable piping is required.

Further, in the above system, when the exhaust pressure from the engine decreases, the exhaust gas can rotationally drive the turbine on the upstream side, but cannot rotate the turbine on the downstream side. Such a situation often occurs.

The present invention is intended to solve the above-mentioned conventional drawbacks, and an object thereof is to provide a plurality of turbines on one axis in a turbocharged engine in which a plurality of turbines are connected in series. An object of the present invention is to provide an engine with a turbocharger in which all turbines operate smoothly even when exhaust gas is reduced, while being arranged and assembled together.

[0007]

In order to achieve the above-mentioned object of the present invention, the present invention provides a turbine structure of a turbo compound engine in which a compressor for air supply is driven by a turbine rotating by exhaust gas. A first generator is provided on a rotating shaft that connects a rotary turbine and a compressor rotationally driven by the rotary turbine, and an axial-flow turbine that operates on exhaust gas of the rotary turbine on a coaxial line with the rotary turbine. And a second generator driven by an axial flow turbine, the turbine structure of a turbo compound engine is provided.

[0008]

[Effect] Even when the exhaust gas flow rate is low, the inlet area is adjusted by the slide shutter to operate the axial turbine efficiently, and when the exhaust gas is low, the opening and closing shutter closes the inlet to stop the operation of the compressor. Efficient power generation.

[0009]

Next, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a turbocharger according to the present invention. As is apparent from the figure, the turbocharger according to the present invention is the first turbo-generator section A.
A second turbo-generator section B is provided at one end and a compressor section C is provided at the other end. The first turbo-generator section A has a turbine inlet 1 connected to an exhaust pipe of an engine (not shown). The turbine inlet 1 communicates with a turbine housing 2. The turbine housing 2 extends integrally up to the second turbo-generator section B, and also serves as a housing for this. Inside the turbine housing 2, a turbine blade 3 is rotatably supported. A rotary shaft 4 is connected to the first turbine blade 3, and the rotary shaft 4 is supported by two bearings 5 and 6. A rotor 8 of a generator made of a permanent magnet is fixed to the rotary shaft 4 via a sleeve 7 and rotates together with the rotary shaft 4. A stator coil 9 of the generator is arranged on the outer circumference of the rotor 8. The turbine constituting the first turbo-generator section A is a radial turbine (convection turbine).
Is.

A second turbine blade 10 is rotatably arranged in the turbine housing 2 extending from the first turbo-generator section A. The second turbine blade 10
Is an axial flow type turbine having an air introduction part 11 and a blade 12. Then, the exhaust gas from the first turbo-generator section A is guided to the blade section 12 through the inlet section 13. A slide shutter 14 for adjusting the amount of air flowing toward the blade portion 12 is provided on the front surface of the blade portion 12.
Is provided, but the details will be described later. A rotary shaft 15 is connected to the second turbine blade 10, and the rotary shaft 15 is supported by two bearings 16 and 17.
A rotor 18 made of a permanent magnet is fixed to the rotating shaft 15 and rotates together with the rotating shaft 15. A stator coil 19 of the generator is arranged on the outer circumference of the rotor 18. Two
Reference numeral 0 is a turbine housing of the second turbo generator unit B, and 21 is a generator casing.

The blade 22 of the compressor section C is fixed to the other end of the rotary shaft 4 of the first turbo-generator section A and rotates with the rotation of the rotary shaft 4. Reference numeral 23 is a compressor housing, and 25 is a blowout hole for compressed air, which is connected to the inlet manifold of the engine. Reference numeral 24 is an intake hole of the compressor. The intake hole 24 and the blowout hole 25 are connected by an intake bypass pipe 26, and an opening / closing shutter 27 is provided at the entrance portion thereof. An actuator 28 opens and closes the opening / closing shutter 27. Reference numeral 33 is a pressure sensor that senses the air pressure inside the inlet portion 13.

FIG. 2 is a front view showing the details of the slide shutter 14 for changing the area of the input port of the second turbo generator section B. The slide shutter 14 is attached to an arm 30 that is rotatably supported by a shaft support pin 29, and the movement of an actuator 32 provided in a drive unit 31 in the direction of the arrow causes the slide shutter 14 to move to a solid line position and a dotted line position. A desired position between the two positions can be taken, and the inflow area of the second turbine blade 10 which is an axial turbine is adjusted.

Next, the operation of the embodiment of the present invention will be described. When exhaust gas discharged from an exhaust manifold of an engine, which is not shown in the figure, flows in from the turbine inlet 1, the exhaust gas is blown to the first turbine blade 3 and partially expands the second turbine blade. 10
Flow in the direction. During that time, the first turbine blade 3 is rotated by the energy of the exhaust gas, the first turbo generator unit A is operated, and the exhaust gas energy is converted into electric energy to generate electricity. This generated energy is stored in the power storage device. Further, since the blade 22 of the compressor section C is also rotated, the air sucked from the intake hole 24 is compressed, and the compressed air is supplied to the intake manifold of the engine from the blowout hole 25. Of course, at this time, the opening / closing shutter 27 closes the inlet of the intake bypass pipe 26.

On the other hand, the exhaust gas discharged from the first turbo-generator section A flows toward the inlet section 13 and flows into the second turbine blade 10. The pressure sensor 3 detects the exhaust gas pressure discharged from the first turbo generator unit A, and a control device (not shown) drives the drive unit 31 according to the exhaust gas pressure to appropriately move the slide shutter 14. By moving it, the inlet area to the second turbine blade 10 is reduced to a predetermined value. As a result, the entrance is partially closed and the second
Since the flow velocity of the exhaust gas flowing through the turbo generator unit B can be maintained at a predetermined value, the pressure difference between the inlet and the outlet also has an optimum value, and the second turbo generator unit B can efficiently generate power. .. The exhaust gas discharged from the second turbo power generation section B is discharged in the direction of the outside air through the exhaust hole 34.

At the time of partial load such as idling, the opening / closing shutter 27 closes the inlet of the compressor section C. As a result, the compressor section C does not perform the intake work, and the first turbo generator section A exclusively performs the power generation operation. In addition, since the second turbo generator unit B can be operated under partial load, the power generation efficiency in this part is also good.

[0016]

As described in detail above, the present invention is
Since an opening / closing shutter is provided at the inlet of the axial turbine of the second stage, if the inlet area is reduced, the inlet will be partially closed and the flow velocity will increase, so the pressure difference in the turbine of the second stage will also increase. , Power generation here is done efficiently. Further, when the exhaust gas flow rate is low, the operation of the compressor can be stopped by closing the inlet of the compressor with the opening / closing shutter, so the work load of the turbine in the first stage is reduced, and high efficiency power generation can be performed correspondingly. ..

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a front view showing a blade of a second turbo generator.

[Explanation of symbols]

 A ... 1st turbo generator part B ... 2nd turbo generator part C ... Compressor part 1 ... Turbine inlet 2 ... Turbine housing 3 ... 1st turbine blade 4 ... -Rotation shaft 5 ... Bearing 6 ... Bearing 7 ... Sleeve 8 ... Rotor 9 ... Stator coil 10 ... Second turbine blade 11 ... Air introduction part 12 ... Blade part 13・ ・ Inlet part 14 ・ ・ Slide shutter 15 ・ ・ Rotary shaft 16 ・ ・ Bearing 17 ・ ・ Bearing 18 ・ ・ Rotor 19 ・ ・ Stator coil 20 ・ ・ Turbine housing 21 ・ ・ Casing 22 ・ ・ Blade 23 ・ ・ Compressor housing 24 ... Intake hole 25 ... Outlet hole 26 ... Intake bypass pipe 27 ... Opening / closing shutter 28 ... Actuator 29 ... 0 · arm 31 .. driver 32 ... actuator 33 ... pressure sensor

Claims (3)

[Claims] 1. In a turbine structure of a turbo compound engine in which a compressor for air supply is driven by a turbine that rotates by exhaust gas, a first rotary shaft is connected to a rotary type turbine and a compressor that is rotationally driven thereby. A generator is provided, and an axial flow turbine that operates on the exhaust gas of the convective turbine is arranged coaxially with the convective turbine, and a second generator driven by the axial turbine is provided. A turbo compound engine turbine structure characterized in that 2. The turbine structure of a turbo compound engine according to claim 1, wherein a slide shutter for adjusting an inlet area of the axial flow turbine is provided at an inlet of the axial flow turbine. 3. An intake air bypass is provided between an inlet and an outlet of the compressor, and an opening / closing shutter for switching between a compressor flow passage and a bypass flow passage is provided at the inlet thereof. Turbine structure of turbo compound engine.