JPH0687638U - gas turbine - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Regarding a two-shaft gas turbine, the left and right exhaust outlets can be changed without changing the mounting direction of the exhaust duct, and the lubrication of the turbine can be adjusted according to the load condition to provide a cooling medium. Can be changed, and the tip clearance is configured not to increase due to thermal expansion. Further, leakage of lubricating oil from the labyrinth portion during cooling of lubricating oil performed before and after the operation of the turbine is eliminated. [Composition] The exhaust duct is opened symmetrically in the shape of “C”, and a blind lid that can be attached to the other opening is attached to one of the openings, and the other opening is also attached to the one opening. Attachable exhaust connecting pipe. Further, a pipe for sending cooling air from the compressor 10 to the turbine blade was taken out of the turbine, and a separately prepared cooling steam was guided to the same portion. Also, in order to prevent an increase in the tip clearance of the turbine section due to thermal expansion, the shroud is divided into a number of segments. Further, in conjunction with driving of the lubricating oil pump for cooling, compressed air is sent to the labyrinth on the compressor side and the labyrinth on the turbine side to prevent leakage of the lubricating oil.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the configuration of each part of a gas turbine.

[0002]

[Prior art]

 Conventionally, the technology regarding the configuration of the gas turbine is known. For example, it is as disclosed in JP-A-4-231603, JP-A-1-190925, and JP-A-63-143338. Further, the exhaust duct of the gas turbine has conventionally been configured as shown in FIGS. 3, 4 and 5. That is, since it is absolutely necessary to be able to change the direction of the exhaust duct 1 to the upward, leftward, rightward, etc., it is possible to change the direction, but by removing all the mounting bolts 13 at the base of the exhaust duct 11. Therefore, the exhaust duct 11 was switched to the required direction and was tightened again. However, in order to change the exhaust duct 11 as described above, it was necessary to disassemble the entire gas turbine, and it was not possible to easily change the direction of the duct on site. Similarly, the air supply duct 12 can also change direction by attaching and detaching the mounting bolt 13.

[0003]

[Problems to be solved by the device]

 According to the present invention, in a two-shaft gas turbine, when the exhaust duct cannot be taken in the axial direction, the shape of the exhaust outlet flange is made symmetrical so that the exhaust direction can be taken in advance. By using a blind lid on the outlet flange, the left and right exhaust outlet specifications can be changed without changing the mounting direction of the exhaust duct. Also, the height of the exhaust duct is made as low as possible. In addition, the cooling medium can be changed like air and steam according to the low, medium and high load conditions of the gas turbine lubrication. In addition, the tip clearance between the turbine tip and the shroud was designed not to increase due to thermal expansion. In addition, the lubricating oil does not leak from the labyrinth during cooling of the lubricating oil before and after operation of the gas turbine.

[0004]

[Means for Solving the Problems]

 The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. Exhaust ports that allow exhaust air to be discharged on opposite sides with respect to the exhaust duct are opened symmetrically in the shape of "C" in the exhaust duct, and one of the openings can be attached to the other opening. The blind lid having the above is attached, and the exhaust connecting pipe having the connection port attachable to the one opening is attached to the other opening.

Further, in the process of guiding the cooling air from the compressor to the turbine blade, the cooling air pipe is once taken out of the gas turbine, and the separately prepared cooling steam is guided to the portion, and the switching device provided in the process. By means of No. 25, the turbine blade can be cooled in three types, that is, without a cooling medium, with air cooling, and with steam cooling.

Further, in order to prevent an increase in the tip clearance formed between the turbine tip of the gas turbine and the shroud due to thermal expansion, the split type shroud is divided into three or more equal segments. .

Further, in a configuration in which lubricating oil is supplied to the labyrinth on the compressor side or the labyrinth on the turbine side before and after operation of the gas turbine to cool the vicinity of the bearing portion, the compressor side is interlocked with the drive of the lubricating oil pump. The labyrinth 33 and the turbine-side labyrinth portion are provided with a switching mechanism that supplies compressed air from the outside to prevent leakage of lubricating oil.

[0008]

[Action]

 Next, the operation will be described. That is, the exhaust gas discharged from the exhaust duct is guided to the inner surface of the blind lid located on one side of the “C” shape, and the dead space and the inner surface of the inner blind lid of the dead end space are the inner surface of the exhaust communication pipe. In the exhaust deflecting passage formed by, the fluid flows without increasing the back pressure and does not cause surging or output reduction. In addition, by exchanging the exhaust connection duct and blind lid of one gas turbine, it is possible to correspond to the left and right exhaust specifications, and it is possible to change the left and right exhaust specifications without having to disassemble the entire system. Can be done. Also, when the pump is driven by the gas turbine, the exhaust duct is rarely directed upward, and only the left and right exhaust specifications are used, so this requirement can be easily met.

According to the second aspect of the present invention, conventionally, cooling is performed from the compressor to the turbine blades 15 by drilling holes provided in pipes and parts in the engine and passages between other parts. Therefore, when the turbine blade 15 is to be cooled with steam having a higher specific heat than air and a high cooling effect, it is impossible to switch between air and steam inside the engine. The present invention could be solved by taking out compressed air from the outside of the engine and mixing it with steam in this part. Further, for example, when the load is low, there is no cooling medium, when the load is medium, the cooling medium is air, and when the load is high, the cooling medium is steam. As a result, the turbine inlet temperature can be made even higher than that during air cooling, and the output and thermal efficiency are increased. Further, since the cooling steam source can be obtained from the exhaust heat of the gas turbine, it is possible to obtain the output and thermal efficiency above the turbine inlet rising temperature. Further, as compared with the case of constant steam cooling, accumulation of water stains on the inner surface of the turbine blade 15 can be reduced, and cold water for steam can be saved.

Further, the structure of claim 3 improves the turbine efficiency. Moreover, since it is segmented, almost no tensile stress in the circumferential direction occurs. Further, by selecting a linear expansion material that can sufficiently absorb the thermal expansion of the support portion, the increase in the chip clearance can be suppressed to zero.

Since the lubricating oil pump is automatically operated to refuel and cool the bearing portion before and after the engine is stopped, the lubricating oil leaks to the outside. Since compressed air is sent to the outside of the compressor-side labyrinth 33 and the turbine-side labyrinth 34 so that it does not exist, the problem of leakage of lubricating oil has been solved.

[0012]

【Example】

 Next, examples will be described. FIG. 1 shows an exhaust duct of a two-shaft gas turbine according to the present invention, a front sectional view of the gas turbine, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 shows an exhaust duct of a conventional two-shaft gas turbine. FIG. 4 is a front cross-sectional view showing the structure, FIG. 4 is a side view of a conventional two-shaft gas turbine exhaust duct with the exhaust duct 11 facing left, and FIG. 5 is the same conventional two-shaft gas turbine exhaust duct. FIG. 6 is a side view showing a state where the exhaust duct 11 is directed to the right side, FIG. 6 is a view showing a configuration in which a cooling medium of a turbine blade can be switched to air and steam, and FIG. 7 is a turbine tip clearance adjustment method in a split shroud. FIG. 8 is an enlarged sectional view, FIG. 8 is a side view of the shroud 30 divided into 12 equal parts, FIG. 9 is a front sectional view of the same shroud 30 that is segmented, and FIG. Illustrates the increase of the lance, FIG. 11 is a front sectional view showing the sealing mechanism when the lubricant priming of the gas turbine.

1 and 2, the exhaust duct of the two-shaft gas turbine of the present invention will be described. Air is taken in from the air supply duct 22, enters the radial compressor 10 rotating at high speed, increases the pressure and speed by the impeller 23, and the moving erg is converted into static pressure by the diffuser. The compressed air flows into the main casing 8, reaches the gas generator 9 while being further decelerated, is mixed with fuel, and is continuously burned. The hot gas passes through the volute and enters the turbine nozzle with a uniform temperature distribution, and the gas is expanded by the nozzle to rotate rotational energy through the low pressure turbine rotor 24 and the high pressure turbine rotor 26.

The rotational force of the low-pressure turbine rotor 24 and the high-pressure turbine rotor 26 is used to power the radial compressor 10 in the preceding stage constituting the gas turbine and auxiliary power. The gas further expands in the power turbine rotor 2 through the internal duct, and the rotational force of the power turbine rotor 2 is transmitted to the gear box 5 and, after deceleration, transmitted to the output shaft 19. The exhaust gas passes through the exhaust diffuser 3 and is released to the atmosphere from the exhaust duct 1 and the exhaust connecting pipe 7 or is supplied to the waste heat boiler.

The combustion gas that has passed through the power turbine rotor 2 passes through the exhaust diffuser 3 and is sent to the exhaust duct 1. The exhaust duct 1 is provided with left and right outlet flanges 1L and 1R. In the case of left exhaust, an exhaust connecting pipe 7 is attached to the outlet flange 1L, and a blind lid 6 is attached to the right outlet flange 1R. Installed and closed. Further, in the case of right exhaust, an exhaust connecting pipe 7 is attached to the outlet flange 1R. A blind lid 6 is attached to the outlet flange 1L. The shape of the exhaust duct 1 is surrounded on a semicircle by a support 4 that connects the gearbox 5 and the main casing 8 on the side of the gas generator 9, and constitutes a passage for exhausting from the upper half to the left and right. is doing. Reference numeral 17 is a governor actuator, 16 is a fuel pump, and 28 is a starter.

Next, referring to FIG. 6, a cooling mechanism for the turbine blades 15 will be described. The turbine blade 15 is located in front of the low pressure turbine rotor 24 and the high pressure turbine rotor 26, and guides the compressed air. In the process of guiding the cooling air from the compressor to the turbine blades 15, the cooling air pipe is once taken out of the engine and the steam is guided from the other side, and the cooling medium can be switched to air and steam by the switching device 25. There is. Reference numeral 29 is a cooling medium storage chamber.

Conventionally, cooling is performed from the compressor to the turbine blades 15 by means of drill holes provided in pipes and parts in the engine and passages between other parts. Therefore, when the turbine blade 15 has a specific heat larger than that of air and is to be cooled with steam having a high cooling effect, it is impossible to switch between air and steam inside the engine. The present invention could be solved by taking compressed air out of the engine and mixing it with steam in this part.

For example, when the load is low, there is no cooling medium, when the load is medium, the cooling medium is air, and when the load is high, the cooling medium is steam. As a result, the turbine inlet temperature can be made even higher than that during air cooling, and the output and thermal efficiency are increased. Further, since the cooling steam source can be obtained from the exhaust heat of the gas turbine, it is possible to obtain an output and thermal efficiency higher than the turbine inlet rising temperature. In addition, accumulation of water stains on the inner surface of the turbine blade 15 can be reduced, and cold water for steam can be saved as compared with the case of performing constant steam cooling.

Next, referring to FIG. 7, a method of adjusting the turbine tip clearance in the split shroud will be described. In an axial turbine, a circumferentially divided shroud with a linear expansion coefficient selected so that it has an expansion amount corresponding to the expansion difference between the thermal expansion of the turbine rotor during operation and the thermal expansion of the shroud fulcrum is shown. ing. As shown in FIG. 10, in the conventional shroud, the amount of increase in the tip clearance is obtained by adding the thermal expansion amount of the shroud 30 to the thermal expansion amount of the shroud support portion 31, and subtracting the thermal expansion amount of the turbine chip 26a. It was a difference. In a conventional integrated shroud, the shroud thermally expands in the radial direction, increasing tip clearance. This is not preferable from the viewpoint of thermal efficiency of the turbine. Further, due to the difference in thermal expansion between the shroud support portion 31 and the main body of the shroud 30, excessive stress may be applied to the shroud 30 depending on the supporting method.

In the present configuration, as shown in FIG. 8, the shroud 30 is divided into segments each having a circumference of about 12 pieces. Then, the shroud 30 for each segment is fixed to the shroud support portion 31 by the outer bonnet. With this configuration, the thermal deformation of the portion facing the turbine tip 26a is deformed in the direction in which the radius becomes smaller, that is, the tip clearance decreases. With this, turbine efficiency can be improved. Also, since it is segmented, tensile stress in the circumferential direction hardly occurs. Also, by selecting a linear expansion material that can sufficiently absorb the thermal expansion of the support portion, the increase in the tip clearance can be suppressed to zero. 30a is a bolt hole for fixing.

Referring to FIG. 11, a sealing mechanism at the time of priming the lubricating oil of the gas turbine will be described. In other words, in order to prevent the bearing temperature from rising before and after the gas turbine is started and stopped, the lubricating oil that circulates is prevented from leaking from the labyrinth seal in the vicinity of the bearing in a configuration in which a separate lubricating oil pump is operated and cooled. Therefore, it is possible to supply seal air from an external air source.

That is, during normal operation of the gas turbine, compressor outlet pressure air is supplied to the compressor-side labyrinth 33 to seal the compressor-side labyrinth 33. The air seal line 38 is provided with a check valve 37 and a switching valve 36 interlocked with an operation ON-OFF signal of the pre-post lubricating oil pump. Sealed compressed air is supplied from the outside through the switching valve 36. The compressed air is stored in the air tank 35 by a separately placed compressor.

As described above, when the lubricating oil pump is automatically operated to refuel and cool the bearing portion before and after the engine is stopped, the lubricating oil is prevented from leaking to the outside of the compressor. Since the compressed air is sent to the outside of the labyrinth 33 and the turbine side labyrinth 34, it is possible to solve the problem that the lubricating oil leaks.

[0024]

【The invention's effect】

 Since the present invention is configured as described above, it has the following effects. That is, since it is configured as in claim 1, exhaust ports capable of exhausting exhaust air to opposite sides with respect to the exhaust duct are opened symmetrically in a "C" shape in the exhaust duct, and one of the openings is opened. , The blind lid with the connection port that can be attached to the other opening was attached, and the exhaust communication pipe with the connection port that could be attached to the one opening was attached to the other opening. To play. That is, the exhaust gas discharged from the exhaust duct is guided to the inner surface of the blind lid located on one side of the “C” shape, and the dead space and the inner surface of the inner blind lid of the dead end space are the inner surface of the exhaust communication pipe. In the exhaust deflecting passage formed by, the fluid flows without increasing the back pressure and does not cause surging or output reduction. In addition, by exchanging the exhaust connection duct and blind lid of one gas turbine, it is possible to correspond to the left and right exhaust specifications, and it is possible to change the left and right exhaust specifications without having to disassemble the entire system. Can be done. Also, when the pump is driven by the gas turbine, the exhaust duct is rarely directed upward, and only the left and right exhaust specifications are used, so this requirement can be easily met.

Further, according to the second aspect of the invention, conventionally, cooling from the compressor to the turbine blades 15 is performed by drilling holes provided in the pipes and parts in the engine and the passages between other parts. Therefore, when the turbine blade 15 is to be cooled with steam having a higher specific heat than that of air and a high cooling effect, it is impossible to switch between air and steam inside the engine. The present invention could be solved by extracting compressed air from the outside of the engine and mixing it with steam in this part. Further, for example, when the load is low, there is no cooling medium, when the load is medium, the cooling medium is air, and when the load is high, the cooling medium is steam. As a result, the turbine inlet temperature can be made even higher than when air is cooled, and the output and thermal efficiency increase. Further, since the cooling steam source can be obtained from the exhaust heat of the gas turbine, it is possible to obtain the output and thermal efficiency above the turbine inlet rising temperature. In addition, the accumulation of water stains on the inner surface of the turbine blade 15 can be reduced and the cold water for steam can be saved as compared with the case where steam is constantly cooled.

Further, since it is configured as in claim 3, it is possible to improve turbine efficiency. Moreover, since it is segmented, almost no tensile stress in the circumferential direction occurs. In addition, by selecting a linear expansion material that can sufficiently absorb the thermal expansion of the support portion, the increase in the tip clearance can be suppressed to zero.

Since the lubricating oil pump is automatically operated to refuel and cool the bearing portion before and after the engine is stopped, the lubricating oil leaks to the outside. Since compressed air is sent to the outside of the compressor-side labyrinth 33 and the turbine-side labyrinth 34 so that it does not exist, the problem of leakage of lubricating oil has been solved.

[Brief description of drawings]

FIG. 1 is a front sectional view of a gas turbine showing an exhaust duct of a two-shaft gas turbine of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a front sectional view showing the structure of an exhaust duct of a conventional two-shaft gas turbine.

FIG. 4 is a side view of an exhaust duct of a conventional two-shaft gas turbine in a state where the exhaust duct 11 is directed to the left.

FIG. 5 is a side view of the exhaust duct of the conventional two-shaft gas turbine in a state in which the exhaust duct 11 faces the right side.

FIG. 6 is a view showing a configuration in which a cooling medium of a turbine blade can be switched to air and steam.

FIG. 7 is an enlarged cross-sectional view showing a turbine tip clearance adjustment method for a split shroud.

FIG. 8 is a side view of the shroud 30 divided into 12 equal segments.

FIG. 9 is a front sectional view of the shroud 30 which is also segmented.

FIG. 10 is a view showing the amount of increase in tip clearance.

FIG. 11 is a front cross-sectional view showing a sealing mechanism at the time of lubricating oil priming of a gas turbine.

[Explanation of symbols]

 1 Exhaust Duct 2 Power Turbine Rotor 3 Exhaust Diffuser 4 Support 5 Gearbox 15 Turbine Blade 25 Switching Device 33 Compressor Labyrinth 34 Turbine Labyrinth

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F02C 7/28 A 7910-3G (72) Creator Shinichiro Kinoshita No. 1 Chayacho, Kita-ku, Osaka City, Osaka Prefecture No. 32 Yanmar Diesel Co., Ltd. (72) Inventor Hideki Terazono No. 32 Chayamachi, Kita-ku, Osaka City, Osaka Prefecture Yanmar Diesel Co., Ltd.

Claims (4)

[Scope of utility model registration request] 1. Exhaust ports capable of discharging exhaust air to mutually opposite sides with respect to an exhaust duct are opened symmetrically in a V-shape in the exhaust duct, and can be attached to one of the openings and the other opening. A gas turbine characterized in that a blind lid having various connecting ports is attached, and an exhaust connecting pipe having a connecting port attachable to one opening is attached to the other opening. 2. A switching device provided in the stroke in which the cooling air pipe is taken out to the outside of the gas turbine in the step of guiding the cooling air from the compressor to the turbine blade and the cooling steam prepared separately is guided to the portion. The gas turbine is characterized in that the cooling of the turbine blades can be switched among three types, that is, no cooling medium, air cooling, and steam cooling. 3. A split shroud is divided into three or more equal segments to prevent an increase in the tip clearance formed between the turbine tip of the gas turbine and the shroud due to thermal expansion. And a gas turbine. 4. In a structure in which lubricating oil is supplied to a compressor-side labyrinth or a turbine-side labyrinth to cool the vicinity of a bearing portion before and after the operation of a gas turbine, the compressor-side labyrinth and A gas turbine characterized in that a compressed air is externally supplied to a turbine-side labyrinth portion to provide a switching mechanism for preventing leakage of lubricating oil.