JP2008057467A - Gas turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress damage of turbine parts caused by thermal stress, without processing the turbine parts. <P>SOLUTION: A gas turbine conducting combustion gas from a burner 5 to a high pressure turbine 6, comprises an exhaust means 10 discharging at least part of air for combustion supplied to the burner 5 to the outside, when combustion in the burner 5 is stopped. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas turbine, and more particularly to a gas turbine having a turbine with components formed from a ceramic-based material.

  In general, a gas turbine includes a compressor, a combustor, and a turbine. The air compressed by the compressor is combusted together with fuel in the combustor, and the turbine is rotationally driven by the combustion gas generated by this combustion (see Patent Document 1).

In such a gas turbine, high-temperature combustion gas is supplied to the turbine, and the turbine is rotationally driven by receiving combustion gas from blades (turbine blades) included in the turbine. It has become. Since the outlet temperature of the combustion gas changes when the output of the gas turbine changes, the thermal stress generated in the turbine component becomes higher than the thermal stress in the steady state. In particular, if for some reason the fuel shuts off due to an emergency stop or the burner blows out, the turbine components will be exposed to a low temperature gas stream, and the turbine in a high temperature state will be rapidly cooled. . For this reason, a large temperature distribution is generated inside the turbine component, and a higher thermal stress is generated in the turbine component.
For this reason, in the conventional gas turbine, it is set as the turbine component strong against a thermal stress by processing a turbine component, devising a shape, or devising an attachment structure.
JP-A-10-259915

However, depending on the type and usage environment of the gas turbine, it may be difficult to process the turbine parts. For example, in recent years, it has been proposed to form a turbine component with a ceramic material for the purpose of reducing the weight and improving the heat resistance at high temperatures, but the ceramic material has poor workability. For this reason, when a turbine part formed of a ceramic material is employed, a method of processing the turbine part is not realistic.
For this reason, there is a need for a method of reducing the thermal stress applied to the turbine component without devising the shape processing and mounting structure of the turbine component.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to suppress damage to a turbine component due to thermal stress without processing the turbine component.

  In order to achieve the above object, the present invention provides a gas turbine that guides combustion gas from a combustor to a turbine, and at least of combustion air supplied to the combustor when combustion in the combustor is stopped. An exhaust means for exhausting a part to the outside is provided.

  According to the present invention, when combustion in the combustor is stopped for some reason, at least a part of the combustion air is exhausted by the exhaust means. For this reason, at least a part of the combustion air that is conventionally supplied to the turbine via the combustor is exhausted outside without passing through the turbine.

  Further, in the present invention, the exhaust means includes a bypass passage connected to the combustion air passage, a valve installed in the middle of the bypass passage, and the valve according to the combustion state of the combustor. It is possible to employ a configuration comprising a control means for controlling the opening and closing of the.

  Moreover, in this invention, the structure that the said control means judges the combustion state of the said combustor based on the signal input into the fuel supply apparatus with which the said combustor is equipped is employable.

  In the present invention, a configuration is adopted in which temperature detection means for detecting the turbine outlet temperature is provided, and the control means determines the combustion state of the combustor according to the detection result of the temperature detection means. You can also.

  Moreover, in this invention, the structure that the components with which the said turbine is provided is formed from the ceramic type material is employable.

  According to the present invention, even when the combustion in the combustor is stopped for some reason, at least part of the air supplied to the combustor is exhausted outside without passing through the turbine. For this reason, compared with the past, when the combustor stops, the quantity of the air which flows into a turbine can be reduced. Therefore, the temperature drop rate of the turbine component can be relaxed, and the thermal stress applied to the turbine component can be reduced. Therefore, it is possible to suppress damage to the turbine component due to thermal stress without processing the turbine component.

  Hereinafter, an embodiment of a gas turbine according to the present invention will be described with reference to the drawings. In the following description, the case where the gas turbine of the present invention is used in a jet engine will be described. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

  FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a jet engine 1 of the present embodiment. As shown in this figure, the jet engine 1 of this embodiment includes a casing 2, a fan, a high-pressure compressor 9, a combustor 5, a high-pressure turbine 6, a low-pressure turbine 8, a low-pressure shaft 7a, and a high-pressure shaft 7b.

The casing 2 forms the outer shape of the jet engine 1 and houses therein a fan, a high-pressure compressor 9, a combustor 5, a high-pressure turbine 6, a low-pressure turbine 8, a low-pressure shaft 7a, and a high-pressure shaft 7b. An air inlet 21 for taking in outside air into the jet engine 1 is provided on one end side of the casing 2, and the outside air taken in from the air inlet 21 bypasses the core duct 23 a downstream of the fan rotor blade row 3. It is branched into a duct 23b. Although the core duct 23a is connected to the injection port 22, the discharge side end of the bypass duct 23b is configured as a fan nozzle 23c.
In the present embodiment, the casing 2 includes a nacelle positioned on the upstream side of the fan rotor cascade 3.

The fan rotor blade row 3 is composed of a plurality of fan rotor blades 31 (blades) arranged around the rotation axis L and fixed to the low pressure shaft 7a.
The fan outlet guide vane row 4 includes a plurality of fan outlet guide vanes 41 that are arranged around the rotation axis L and are fixed to the casing 2.

  The high-pressure compressor 9 has a configuration in which a plurality of high-pressure compressor rotor blades 91 and high-pressure compressor stationary blades 92 are alternately arranged in the core duct 23a. The high pressure compressor rotor blade 91 is fixed to the high pressure shaft 7b. Further, the high pressure compressor stationary blade 92 is fixed to the casing 2. Such a high-pressure compressor 9 compresses and discharges the supplied air Y by rotating the high-pressure compressor rotor blade 91 with the rotational drive of the high-pressure shaft 7b.

  The combustor 5 is installed on the downstream side of the high-pressure compressor 9. The combustor 5 is provided with an ignition device (not shown) that can supply fuel from the fuel supply device 51. In such a combustor 5, the compressed air Y supplied from the high-pressure compressor 9 side is burned after being mixed with fuel. The combustion gas Z generated by the combustion is discharged from the combustor 5 to the flow path 23.

The high-pressure turbine 6 is installed on the downstream side of the combustor 5, arranged around the rotation axis L, and fixed to the casing, and a plurality of high-pressure turbine stationary blades 62 fixed to the high-pressure shaft 7 b. A high-pressure turbine rotor blade 61 is provided.
The low-pressure turbine 8 is installed downstream of the high-pressure turbine, arranged around the rotation axis L, and fixed to the casing. The low-pressure turbine blades 82 are fixed to the low-pressure shaft 7a. 81.
In the jet engine 1 of the present embodiment, high-pressure turbine parts (for example, the high-pressure turbine rotor blade 61, the high-pressure turbine stator blade 62, and the shroud that surrounds the high-pressure turbine rotor blade 61 and the high-pressure turbine stator blade 62) are ceramics. It is made of an MGC material (Melt-Growth Composites), which is a kind of system material, and thereby achieves weight reduction and heat resistance in a high temperature region.

  As described above, the low-pressure shaft 7a extends in the axial direction L and is fixed to the fan rotor blade row 3 and the low-pressure turbine blade row. As described above, the high-pressure shaft 7b extends in the axial direction L, and is fixed with a high-pressure compressor blade row and a high-pressure turbine blade row. The low pressure shaft 7a and the high pressure shaft 7b are fixed to the casing 2 via a bearing (not shown). A spinner 72 is connected to the tip 71 of the low pressure shaft 7a.

  In the present embodiment, the high-pressure turbine 6 shown in FIG. 2 includes a high-pressure turbine stationary blade 62, a high-pressure turbine rotor blade 61, and a high-pressure shaft 7b, and the gas turbine in the present invention is a fan, a high-pressure compressor 9, The combustor 5, the high pressure turbine 6, the low pressure turbine 8, the high pressure shaft 7 b, and the low pressure shaft 7 a are configured.

When the combustion in the combustor 5 is stopped, the jet engine 1 of the present embodiment transfers air Y (combustion air) from the flow path 23d between the high-pressure compressor 9 and the combustor 5 to the flow path 23d. An exhaust device 10 for exhausting outside is provided.
Here, the exhaust device 10 will be described with reference to FIG. 1 and FIG. 2 schematically showing the exhaust device 10.

  The exhaust device 10 includes a bypass flow path 11 having one end connected to the flow path 23d and the other end connected to the bypass duct 23b, an open / close valve 12 installed in the middle of the bypass flow path 11, And a control device 13 for controlling opening and closing.

  The bypass channel 11 is connected to the channel 23d and the bypass duct 23b as described above. However, as shown in FIG. 1, the connection point between the channel 23d and the bypass duct 23b is connected to the flow of the air Y. It is preferable that it inclines so that it may follow. Thereby, the flow of the air Y can be made smooth. Further, the channel width of the bypass channel 11 is set so that the compressed air Y discharged from the high-pressure compressor 9 can sufficiently flow when the on-off valve 12 is opened.

  In addition, as shown in FIG. 2, a fuel supply stop signal that is input to the fuel supply device 51 when the combustion of the combustor 5 is urgently stopped is simultaneously input to the control device 13. When the fuel supply stop signal is input, the control device 13 determines that the combustion of the combustor 5 has been stopped, and opens the open / close valve 12. That is, the control device 13 determines the combustion state of the combustor 5 based on a signal input to the fuel supply device 51, and opens the opening / closing valve 12 when determining that the combustion of the combustor 5 is stopped. .

In the jet engine 1 of the present embodiment configured as described above, first, the fan rotor blade 31 fixed to the low-pressure shaft 7a rotates around the axis by the rotation of the low-pressure shaft 7a. As a result, outside air (air Y) is taken into the jet engine 1 from the intake port 21.
After the air Y taken into the jet engine 1 passes through the fan rotor blade 31, a part thereof flows into the core duct 23a and a part thereof flows into the bypass duct 23b.
After the air Y flowing into the bypass duct 23b passes through the fan outlet guide vane 41, it is discharged to the outside from the fan nozzle 23c. The air Y flowing into the core duct 23 a is compressed by the high-pressure compressor 9 and then supplied to the combustor 5. The air Y supplied to the combustor 5 is mixed with fuel in the combustor 5 and burned. As a result, combustion gas Z is generated. Then, the jet engine 1 obtains thrust by a reaction in which the combustion gas Z is injected from the injection port 22.
The combustion gas Z passes through the high pressure turbine 6 and the low pressure turbine 8 before reaching the injection port 22 from the combustor 5. The high pressure turbine rotor blade 61 receives the combustion gas Z, and gives rotational power to the high pressure shaft 7b in one direction. Further, the low-pressure turbine rotor blade 81 receives the combustion gas Z, and gives rotational power to the low-pressure shaft 7a in one direction. As a result, since the high-pressure shaft 7b and the low-pressure shaft 7a rotate, it is possible to continue to rotate the high-pressure compressor rotor blade row fixed to the high-pressure shaft 7b and the fan rotor blade row 3 fixed to the low-pressure shaft 7a.

In the conventional jet engine, when the combustion of the combustor 5 is urgently stopped for some reason, such as when the fuel supply to the combustor 5 is stopped due to troubles of other equipment or the like, the high-pressure compressor 9 to the combustor The air Y supplied to 5 is supplied to the turbine without being used for combustion. For this reason, the turbine component that has been exposed to the high-temperature combustion gas during combustion is exposed to a large amount of air Y, and the turbine component is rapidly cooled. And a strong thermal stress will be applied to a turbine component.
On the other hand, the jet engine according to the present embodiment includes the exhaust device 10. When the fuel supply to the combustor 5 is stopped for some reason, a fuel supply stop signal is input to the control device 13. The control device 13 opens the opening / closing valve 12. As a result, much of the air Y exhausted from the high-pressure compressor 9 flows into the bypass passage 11 and is exhausted to the outside through the bypass duct 23b. For this reason, the amount of air supplied to the turbine is reduced, and the thermal stress applied to the turbine component can be reduced.
Since the bypass flow path 11 is opened to the outside by opening the opening / closing valve 12, most of the high-pressure air Y naturally flows into the bypass flow path 11. However, in consideration of the case where the air Y does not flow into the bypass flow path 11 even if the opening / closing valve 12 is opened for some reason, a forced discharge means for forcing the air Y to flow into the bypass flow path 11 and discharging is installed. It doesn't matter.

Thus, in the jet engine 1 of this embodiment, the temperature fall rate of a turbine component can be relieved and the thermal stress concerning a turbine component can be reduced. Therefore, it is possible to suppress damage to the turbine component due to the thermal stress without processing the turbine component for adopting a structure that can withstand the thermal stress as in the related art.
Therefore, it is possible to form a turbine component from a brittle material (ceramic material) that is difficult to process like the jet engine 1 of the present embodiment, and to reduce the weight and the temperature of the jet engine 1. .
As described above, according to the jet engine 1 of the present embodiment, even when the turbine part is formed of a ceramic material, damage due to thermal stress can be suppressed, and a lightweight and highly heat-resistant jet engine can be realized. It becomes possible.

  In addition, when the bypass flow path 11 is connected to the flow path between the combustor 5 and the high-pressure turbine stationary blade 62, the air Y that has become high temperature by passing through the combustor 5 immediately after the combustion is stopped is bypassed. In order to flow into the flow path, it is necessary to make the bypass flow path and the open / close valve heat resistant to withstand high temperatures, which is not realistic. On the other hand, in the jet engine 1 of the present embodiment, the bypass flow path 11 of the exhaust device 10 is connected to the flow path 23 d between the high pressure compressor 9 and the combustor 5. For this reason, it is not necessary to make the bypass passage 11 and the opening / closing valve 12 heat resistant to withstand high temperatures.

FIG. 3 is a comparative example of the jet engine 1 of the present embodiment and a conventional jet engine, and shows the time change of the stress applied to the high-pressure turbine stationary blade 62. In FIG. 3, the horizontal axis represents time, and the vertical axis represents the specific stress obtained by dividing the stress applied to the high-pressure turbine stationary blade 62 by the breaking stress value of the ceramic. (A) is a case of the jet engine 1 of this embodiment, (b) is a case of the conventional jet engine.
As can be seen from FIG. 3, the high-pressure turbine stationary blade 62 in the jet engine 1 of this embodiment, that is, the jet engine including the exhaust device 10, is not subjected to stress greater than the specific stress 1. On the other hand, the high pressure turbine stationary blade 62 in the conventional jet engine is subjected to a stress of 1 or more. Therefore, according to the jet engine 1 of this embodiment, it turns out that the maximum stress concerning the high-pressure turbine stationary blade 62 can be reduced.

  As mentioned above, although preferred embodiment of the gas turbine which concerns on this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, the case where the gas turbine of the present invention is used in a jet engine has been described. However, the present invention is not limited to this, and can be applied to various gas turbines. For example, the present invention can also be applied to marine gas turbines and power generation gas turbines.

Moreover, in the said embodiment, the other end of the bypass flow path 11 shall be connected to the bypass duct 23b. However, the present invention is not limited to this, and may be exposed to the outside of the casing 2, for example, as shown in FIG.
Moreover, in the said embodiment, although the bypass flow path 11 was formed in the bypass duct 23b side, it is also possible to form the bypass flow path 11 in the high voltage | pressure shaft 7b side.

In the above embodiment, the combustion state of the combustor 5 is determined based on whether or not the fuel supply stop signal is input to the control device 13. However, the present invention is not limited to this. For example, a sensor (temperature detection means) for detecting the temperature of the turbine outlet, that is, the injection port 22, a sensor (temperature detection means) for detecting the high-pressure turbine outlet temperature, or A sensor (temperature detecting means) for detecting the blade surface temperature of the high-pressure turbine stationary blade 62, a sensor (temperature detecting means) for detecting the blade surface temperature of the high-pressure turbine rotor blade 61, or the blade surface temperature of the low-pressure turbine stationary blade 82. A sensor (temperature detection means) for detecting or a sensor (temperature detection means) for detecting the blade surface temperature of the low-pressure turbine rotor blade 81 is provided, and combustion is performed based on signals input from either of these sensors or a plurality of sensors. The combustion state of the vessel 5 may be determined. For example, when a sudden temperature drop occurs, it can be determined that the combustion state of the combustor 5 has stopped.
By adopting such a configuration, even if the fuel is supplied to the combustor 5 and the combustion is stopped (for example, the combustion of the combustor 5 is blown off), the air Y is exhausted by the exhaust device 10. It becomes possible.

It is sectional drawing which showed typically the schematic structure of the jet engine in one Embodiment of this invention. It is the figure which showed typically the exhaust apparatus with which the jet engine in one Embodiment of this invention is provided. It is a comparative example of the jet engine in one Embodiment of this invention, and the conventional jet engine. It is sectional drawing which showed typically schematic structure of the modification of the jet engine in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Jet engine, 5 ... Combustor, 51 ... Fuel supply device, 6 ... High-pressure turbine (turbine), 61 ... High-pressure turbine rotor blade, 62 ... High-pressure turbine stationary blade, 8 ... Low-pressure turbine ( Turbine), 81 ... Low pressure turbine blade, 82 ... Low pressure turbine stationary blade, 10 ... Exhaust device (exhaust means), 11 ... Bypass flow path, 12 ... Open / close valve, 13 ... Control device (control means) )

Claims (5)

A gas turbine for directing combustion gas from a combustor to a turbine,
A gas turbine comprising exhaust means for exhausting at least part of combustion air supplied to the combustor to the outside when combustion in the combustor is stopped. The exhaust means includes a bypass flow path connected to a flow path for combustion air, a valve installed in the middle of the bypass flow path, and a control means for controlling opening and closing of the valve according to the combustion state of the combustor The gas turbine according to claim 1, further comprising: The gas turbine according to claim 2, wherein the control unit determines a combustion state of the combustor based on a signal input to a fuel supply device provided in the combustor. The gas turbine according to claim 2, further comprising a temperature detection unit that detects an outlet temperature of the turbine, wherein the control unit determines a combustion state of the combustor according to a detection result of the temperature detection unit. . The gas turbine according to any one of claims 1 to 4, wherein a component included in the turbine is made of a ceramic material.

Images