JP2001193476A - Device and method for starting multi-shaft gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine for power generation, whose starting device is simplified. SOLUTION: A clutch device 11 for joining a first shaft 5 and a second shaft 6 together and separating them is installed in the multi-shaft gas turbine provided with the first shaft 5 fitted with a compressor 1 and a high-pressure turbine 3 and the second shaft 6 fitted with an output turbine 4 and a generator 7. The first shaft 5 is connected to the second shaft 6, to start the gas turbine with the generator 7 as an electric motor. After starting, the first shaft 5 is separated from the second shaft 6 to put the gas turbine into operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for starting a multi-shaft gas turbine.

[0002]

2. Description of the Related Art A gas turbine includes a compressor for compressing air, a combustor for blowing fuel into compressed air for combustion, and a high-pressure turbine and a low-pressure turbine rotated by combustion gas. In some cases, an intermediate pressure turbine is provided between the high pressure turbine and the low pressure turbine. Low pressure turbines are also called power turbines. The compressor, the high-pressure turbine, and the output turbine may be mounted on one shaft (shaft), or the compressor and the high-pressure turbine may be mounted on one shaft, and the output turbine may be mounted on another shaft. When it has two or more shafts as in the latter case, it is called a multi-shaft gas turbine.

FIG. 6 is a diagram schematically showing a configuration of a conventional gas turbine for power generation. The compressor 1, the combustor 2, the high-pressure turbine 3, and the output turbine 4 are arranged in this order. First
A shaft 5 and a second shaft 6 passing through the first shaft 5 are provided. The compressor 2 and the high-pressure turbine 3 for driving the compressor 2 are mounted on the first shaft 5. An output turbine 4 for driving this is mounted. A gear device 8 is provided at the end of the first shaft 5 on the compressor 1 side.
And is connected to the external power unit 9. As the external power unit 9, an electric motor or the like is used.

In starting the gas turbine, the first shaft 5 is driven by the external power unit 9, the compressor 1 and the high-pressure turbine 3 are rotated, and the combustor 2 injects fuel into compressed air to generate combustion gas. When the high pressure turbine 3 drives the compressor 2 by the combustion gas and reaches a predetermined number of revolutions, the operation is terminated and the operation state is entered.

[0005]

As described above, the gas turbine requires a device for starting, and in the conventional multi-shaft gas turbine for power generation, the power is attached to the first shaft on which the compressor and the high-pressure turbine blade are mounted. , A power transmission shaft, an external power unit, and the like. The mechanism was complicated by these devices. Further, even after the start, the gear unit and the like rotate, causing power loss. When an electric motor is used as the external power unit, it may be used as a generator after starting.

The present invention has been made in view of the above problems, and has as its object to provide a gas turbine for power generation with a simplified starting device.

[0007]

In order to achieve the above object,
An invention according to claim 1 is a multi-shaft gas turbine including a first shaft connected to a compressor and a high-pressure turbine, and a second shaft connected to an output turbine and a generator.
A connection mechanism for connecting and disconnecting the first shaft and the second shaft is provided.

At the time of starting, the first shaft and the second shaft are connected by a connecting mechanism, and the generator is used as a motor,
After starting, disconnect both shafts. As described above, since the generator is used as the electric motor, it is not necessary to separately provide a power unit for starting, and the entire apparatus is simplified. Further, since the coupling mechanism is disconnected after the start, there is no power loss due to the coupling mechanism during operation.

[0009] In the invention according to claim 2, the coupling mechanism is a clutch device.

Since there are many types of clutch devices and abundant achievements, they are excellent as a coupling mechanism.

According to the third aspect of the present invention, the generator and the compressor are connected, the compressor is rotated by the generator, and the generator and the compressor are separated after reaching a predetermined condition.

[0012] The generator connected to the multi-shaft gas turbine and the compressor are connected, power is supplied to the generator, and the compressor is rotated as an electric motor to start the gas turbine. When the starting is completed and a predetermined operating condition is entered, the generator and the compressor are disconnected. Since the generator is used as the electric motor, there is no need to separately provide a power unit for starting, and the entire device is simplified.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a gas turbine for power generation according to a first embodiment of the present invention. 1 compresses air with a compressor. Reference numeral 2 denotes a combustor which injects fuel into compressed air and ignites to generate combustion gas. Reference numeral 3 denotes a high-pressure turbine which is rotated by combustion gas. Reference numeral 4 denotes an output turbine, which is rotated by the combustion gas exiting the high-pressure turbine 3. Reference numeral 5 denotes a first shaft on which the moving blades of the compressor 1 and the high-pressure turbine 3 are attached, and which transmits the rotation of the high-pressure turbine 3 to the compressor 1. Reference numeral 6 denotes a second shaft, which penetrates the first shaft 5, and has a moving blade of the output turbine 4 attached to a rear end in the front-rear direction of the gas turbine, and a generator 7 attached to a front end.

The front end (compressor side) of the first shaft 5 and the second end
A clutch device 11 is provided on the shaft 6 to connect and disconnect the first shaft 5 and the second shaft 6. As the clutch, a meshing clutch, a friction clutch, an electromagnetic clutch or the like is used. A disk clutch or the like is used as the friction clutch.

A tachometer 12 measures the number of revolutions of the first shaft 5 per unit time. Reference numeral 13 denotes a thermometer that measures the exhaust gas temperature of the output turbine 4. A control unit 14 of the gas turbine controls the clutch device 11.

Next, the operation will be described. First, the clutch device 11 is closed, the first shaft 5 and the second shaft 6 are connected, and a current is supplied to the generator 7 to start the motor as a motor. When the rotation of the compressor 1 increases and a predetermined amount of compressed air is sent to the combustor 2, fuel is injected into the combustor 2 to generate combustion gas. This combustion gas causes the high pressure turbine 3 and the output turbine 4 (the moving blades thereof) to rotate. When the rotation speed rises, the high pressure and power turbine 3,
4, the torque of the motor is reduced. At a predetermined rotational speed, the load becomes zero and the temperature of the exhaust gas also increases. The control unit 14 opens the clutch device 11 and disconnects the first shaft 5 and the second shaft 6 when the rotation speed exceeds a predetermined value and the temperature of the exhaust gas exceeds a predetermined value. This terminates the start. Thereafter, the operation state is entered, and the generator 7 starts power generation. The operation is stopped by stopping the fuel injection.

Next, a second embodiment will be described. FIG.
Shows the configuration of the gas turbine for power generation of the second embodiment. The difference from the first embodiment is that the first shaft 5 and the second shaft 6 abut against each other between the high-pressure turbine 3 and the output turbine 4. Connect and disconnect. Further, the generator 7 is disposed at the rear end of the second shaft 6, that is, behind the gas turbine.

As shown in FIG. 2, the first shaft 5 is provided with the moving blades of the compressor 1 and the high-pressure turbine 3, and the second shaft 6 is provided with the moving blade of the output turbine forward and the generator 7 at the rear end.
Is provided. A clutch device 11 is provided to connect a rear end of the first shaft 5 and a front end of the second shaft 6. As shown by the broken line behind the combustor 2, the combustion gas passage 15
Is provided, so that the combustion gas does not hit the clutch device 11. The operation is the same as in the first embodiment.

Next, the clutch device 1 in each embodiment will be described.
An example of equipment 1 will be described. FIG. 3 shows a case where a jaw clutch is provided, A shows a case of the first embodiment, and B shows a case of the second embodiment. The jaw clutch is a meshing clutch, and includes a moving fitting 23 for moving the first shaft 21 along the key 25 and a stationary fitting 2 fixed to the second shaft 22.
The moving metal 23 and the stationary metal 24 are engaged with each other. The movement of the moving fitting 23 is performed by a driving device such as a spring (not shown).

FIG. 4 shows a case where a disk clutch is provided, A shows a case of the first embodiment, and B shows a case of the second embodiment. The disk clutch is a friction clutch, and the moving disk 33 moves the first shaft 31 along the key 35.
And a stationary disk 34 fixed to the second shaft 32 with a wedge 36. The moving disk 33 and the stationary disk 34 are pressed together and joined by friction. Low impact due to joining with sliding. The moving disk 33 is moved by a driving device such as a spring (not shown).

FIG. 5 shows a case where a conical clutch is provided, A shows the case of the first embodiment, and B shows the case of the second embodiment. The conical clutch is a friction clutch, and the first shaft 4
There is a moving cone 43 that moves 1 along the key 45 and a stationary cone 44 fixed to the second shaft 42 with a wedge 46. The moving cone 43 and the stationary cone 44 are fitted and joined by friction. Low impact due to joining with sliding. The movement of the moving cone 43 is performed by a driving device such as a spring (not shown).

Although the examples of the three types of clutches have been described above, other types of clutches can be used. Such clutches include a constant torque clutch that automatically disengages when the torque becomes larger than a predetermined value, an electromagnetic powder clutch that operates by electromagnetic action, and a fluid coupling that uses oil for power transmission is also used. .

[0023]

As apparent from the above description, the present invention relates to a multi-shaft gas turbine for power generation, comprising a first shaft on which a compressor blade and a high-pressure turbine blade are mounted, an output turbine blade, and a power generator. The second shaft to which the machine is attached is connected and disconnected by the clutch device,
The generator can be used as a starting drive,
Since the conventional external power unit is not required, the mechanism of the entire apparatus is simplified. Since the clutch device is used only at the time of starting, the probability of occurrence of a failure is low, the maintainability of the entire device is improved, and the maintenance cost is reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a second embodiment of the present invention.

FIG. 3 is a diagram showing a case where a jaw clutch is provided.

FIG. 4 is a diagram showing a case where a disk clutch is provided.

FIG. 5 is a diagram showing a case where a conical clutch is provided.

FIG. 6 is a diagram showing a conventional starting device for a multi-shaft power generation gas turbine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Combustor 3 High pressure turbine 4 Output turbine 5 1st shaft 6 2nd shaft 7 Generator 11 Clutch device 12 Tachometer 13 Thermometer 14 Control part 15 Combustion gas passage

Claims (3)

[Claims] 1. A first compressor connected to a compressor and a high-pressure turbine.
In a multi-shaft gas turbine including one shaft and a second shaft connected to an output turbine and a generator,
A starting device for a multi-shaft gas turbine, comprising a connecting mechanism for connecting and disconnecting a shaft and a second shaft. 2. The multi-shaft gas turbine starting device according to claim 1, wherein the coupling mechanism is a clutch device. 3. A start-up of a multi-shaft gas turbine, wherein a generator and a compressor are connected, the compressor is rotated by the generator, and the generator and the compressor are separated after a predetermined condition is reached. Method.