JP2006052910A - Communicating structure of combustor transition pipe and turbine inlet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communicating structure of a combustor transition pipe and a turbine inlet capable of improving turbine efficiency, by optimizing the relative position relationship between the combustor transition pipe and a first stage stationary blade. <P>SOLUTION: A gas turbine generates motive power, by successively passing combustion gas through a plurality of turbine stages composed of the stationary blade 7 and a moving blade 8 arranged in a plurality in the peripheral direction of a combustion gas passage part in the turbine, by making the combustion gas generated by combustion flow in a turbine 6 inlet from the respective combustor transition pipes, by burning fuel by compressed air from an air compressor 4 in combustors 1 arranged in a plurality around a rotary shaft. The combustor transition pipes are communicated with and connected to the turbine inlet so that a wake flow 12 formed between the adjacent combustor transition pipes 5 is made to flow in the pressure surface 7a side near the leading edge of the first stage stationary blade. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication structure between a combustor transition and a turbine inlet in a gas turbine.

  In general, a gas turbine includes an air compressor (hereinafter sometimes referred to as a “compressor”), a combustor, and a turbine as main components, and the combustor is disposed between the compressor and the turbine that are directly connected to each other through a rotating shaft. The air serving as the working fluid is sucked into the compressor by the rotation of the rotating shaft and compressed, the compressed air is introduced into the combustor and burned together with the fuel, and the high-temperature and high-pressure combustion gas is converted into the turbine. The rotary shaft is driven to rotate together with the turbine. Such a gas turbine is utilized as a drive source by connecting a generator or the like to the front end of the rotating shaft (see Patent Document 1).

JP 2001-107703 A

  By the way, there are a plurality of combustors in the gas turbine, and high-temperature gas from the combustors flows from the tail cylinder into the turbine first stage stationary blades. Since there are as many combustors as the combustor with respect to the turbine inlet and there is a structural part (tail pipe side wall part having a predetermined thickness) between adjacent ones, the wake flow is on the turbine side behind it. (Wake or wake) occurs. For this reason, a distribution is formed in the circumferential direction in the flow at the turbine inlet.

  However, at present, the positional relationship between the combustor tail and the stationary blade is appropriately determined, or as disclosed in Patent Document 1, the temperature distribution of the turbine first stage stationary blade is considered in consideration of the temperature distribution at the combustor outlet. It is set to reduce inflow. Therefore, depending on the relative position of the combustor tail (wake flow) and the first stage stationary blade, there is a problem that the turbine efficiency is lowered.

  The present invention has been made in view of the above-mentioned situation, and has a communication structure between a combustor tail cylinder and a turbine inlet that can improve the turbine efficiency by optimizing the relative positional relationship between the combustor tail cylinder and the first stage stationary vane. The purpose is to provide.

  In order to achieve such an object, a communication structure between a combustor transition and a turbine inlet according to the present invention is configured to burn fuel with compressed air from a compressor in a plurality of combustors arranged around a rotation axis. The combustion gas generated thereby flows into the turbine inlet from each combustor tail tube, and a plurality of turbine stages including a plurality of stationary blades and moving blades arranged in the circumferential direction of the combustion gas passage portion in the turbine are sequentially provided. In a gas turbine that generates power by passing through, a combustor tail and a turbine inlet so that a wake flow formed between the adjacent combustor tails flows into a pressure surface side near the front edge of the first stage stationary blade. It is characterized by being connected in communication.

  Further, the wake flow is caused to flow from a leading edge of the first stage stationary blade into a range of a quarter pitch of the first stage stationary blade.

  Further, the relative position relationship between the wake flow and the first stage stationary blade is maintained without providing the distribution of the leading edge position of the first stage stationary blade in the circumferential direction in the height direction.

  Further, the circumferential position of the side surface of the transition piece is distributed according to the position of the leading edge of the first stage stationary blade, and the relative positional relationship between the wake flow and the first stage stationary blade is maintained.

  According to the configuration of the present invention, the downflow due to shearing of the wake flow and the updraft due to the circulation of the first stage stationary blade cancel each other and the incidence is reduced. In addition to the improvement, the cooling effect of the pressure surface of the first stage stationary blade by the seal air from between the combustor transitions can be obtained.

  Hereinafter, a communication structure between a combustor transition piece and a turbine inlet according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing a relative positional relationship between a combustor tail cylinder and a first stage stationary blade showing Embodiment 1 of the present invention, FIG. 2 is a schematic configuration diagram of a main part of a gas turbine, and FIG. 3 is a combustor tail cylinder (wake flow). FIG. 4 is a graph showing the relative positions of the combustor tail cylinder and the first stage stationary blade, which are preferable from the viewpoint of performance and cooling, and FIG. 5 is a graph showing the relative positions of the combustor tail cylinder and the first stage stationary blade. It is the graph which analyzed the relationship between a relative position and efficiency.

  As shown in FIG. 2, in the gas turbine, a plurality of (eg, 16) combustors 1 are disposed around a main shaft (rotating shaft) (not shown). In each combustor 1, the fuel F injected from the fuel nozzle 3 provided adjacent to the combustor inner cylinder 2 and the air compressor (hereinafter simply referred to as a compressor) 4 are discharged and introduced upstream of the combustor inner cylinder 2. The compressed air PA thus mixed is mixed and then burned in the combustion region downstream of the combustor inner cylinder 2 or upstream of the combustor tail cylinder 5 and introduced into the turbine 6 as high-temperature and high-pressure combustion gas CG. In the turbine 6, the combustion gas CG is sequentially passed through and expanded through a plurality of turbine stages including the stationary blades 7 and the moving blades 8 to generate power, drive the compressor 4 and output an excessive driving force to the outside. Like to do.

  Further, it is necessary to control the ratio (air-fuel ratio) between the compressed air PA and the fuel F introduced into the combustor inner cylinder 2 so as to be an optimum value according to the operating state of the gas turbine (that is, the amount of injected fuel). However, for this purpose, the entire compressed air PA is not introduced into the combustion region of the combustor 1, but a part thereof is bypassed and flows into the combustor tail cylinder 5 from the passenger compartment 9. For this purpose, a bypass valve 10 is provided, and a part of the compressed air PA flows into and supplied to the combustor tail cylinder 5 from the opening of the bypass pipe 11 provided in the vehicle compartment 9.

  In this embodiment, as shown in FIG. 1, the combustor is configured such that the wake flow 12 formed between the adjacent combustor tail cylinders 5 flows into the pressure surface 7 a side near the front edge 7 c of the first stage stationary blade 7. The transition piece 5 and the inlet of the turbine 6 are connected in communication. That is, as shown in FIG. 4, the θ / θ tail cylinder flows from the front edge 7 c of the first stage stationary blade 7 into a range of ¼ pitch of the first stage stationary blade (in the broken line region in FIG. 4). It has become.

  Thus, by setting the relative position between the wake flow 12 and the first stage stationary blade 7, the turbine efficiency (first stage efficiency) is improved and the cooling action by the seal air from between the combustor tail cylinders 5 is 1. Since the surface maximum temperature of the stage vane 7 is lowered, the amount of cooling air on the pressure surface 7a of the stage 1 vane 7 can be reduced (see FIG. 4).

  The improvement in the turbine efficiency is confirmed by the analysis results of the present inventors as shown in FIG. This is because, as shown in FIG. 3, the blow-down due to the shear of the wake flow 12 and the blow-up due to the circulation of the first-stage stationary blade 7 cancel each other, and the incidence (attack angle) is reduced. It is considered that the pressure efficiency on the pressure surface 7b side is lowered and the turbine efficiency is improved.

  On the contrary, in the current actual machine equivalent, the wake flow 12 is in a relative position so as to flow from the front edge 7c of the first stage stationary blade 7 to the suction surface 7b side. Incidence (attack angle) is increased by blowing up by the circulation of the air and the flow velocity on the suction surface 7b side of the first stage stationary blade 7 near the front edge 7c is increased, so that it is considered that the turbine efficiency is lowered.

  FIG. 6 is a schematic diagram showing the relative positional relationship between the combustor tail cylinder and the first stage stationary blade in the second embodiment of the present invention.

  This is an example in which the side wall of the combustor tail cylinder 5 in the first embodiment is formed as thin as possible to suppress the generation of the wake flow 12 itself and the pressure loss in the combustor tail cylinder 5 is reduced. Therefore, the turbine efficiency can be further improved.

  FIG. 7 is a schematic diagram showing the relative positional relationship between the combustor tail cylinder and the first stage stationary blade in the third embodiment of the present invention.

  This is to reduce the pressure loss in the combustor tail cylinder 5 by forming the outlet side of the side wall of the combustor tail cylinder 5 in the first embodiment as thin as possible to suppress the generation of the wake flow 12 itself. In this example, the turbine efficiency can be further improved.

  FIG. 8 is a schematic diagram showing a relative positional relationship between the combustor tail cylinder and the first stage stationary blade in the fourth embodiment of the present invention.

  This is to reduce the pressure loss in the combustor tail cylinder 5 by suppressing the generation of the wake flow 12 itself by reducing the distance L between the combustor tail cylinder 5 and the first stage stationary blade 7 in the first embodiment as much as possible. In this example, the turbine efficiency can be further improved.

  FIG. 9 is a schematic diagram showing a relative positional relationship between the combustor tail cylinder and the first stage stationary blade in the fifth embodiment of the present invention. FIG. 9 is a view of the combustor tail tube viewed from the downstream side of the combustion gas flow.

  This is an example in which the relative position relationship between the wake flow 12 and the first stage stationary blade 7 in the first embodiment is maintained without providing the distribution of the front edge 7c position of the first stage stationary blade 7 in the first embodiment in the circumferential direction in the height direction. The turbine efficiency can be further improved.

  FIG. 10 is a schematic diagram showing the relative positional relationship between the combustor tail cylinder and the first stage stationary blade in the sixth embodiment of the present invention. FIG. 10 is a view of the combustor tail tube seen from the downstream side of the combustion gas flow.

  This is because the circumferential position of the side surface (side wall) of the combustor tail cylinder 5 is distributed according to the position of the leading edge 7c of the first stage stationary blade 7 in the first embodiment, and the relative positional relationship between the wake flow 12 and the first stage stationary blade 7 in the first embodiment. In this example, the turbine efficiency can be further improved.

  FIG. 11 is a schematic diagram showing a relative positional relationship between a combustor tail cylinder, a first stage stationary blade, and a second stage stationary blade, showing Embodiment 7 of the present invention.

  In the first embodiment, when the number of stationary blades of the first stage stationary blade 7 and the second stage stationary blade 7 is equal or the ratio is an integer, the wake flow 12 integrated between the combustor tail cylinder 5 and the first stage stationary blade 7 is obtained. This is an example in which the relative positional relationship similar to the relative positional relationship between the wake flow 12 and the first stage stationary blade 7 in the first embodiment is maintained, and the two-stage stationary blade 7 is caused to flow into the second stage. Improvement can be achieved.

  FIG. 12 is a schematic diagram showing a relative positional relationship between the combustor tail cylinder and the first stage stationary blade in the eighth embodiment of the present invention. FIG. 12 is a view of the combustor tail tube viewed from the downstream side of the combustion gas flow.

  This is because the circumferential position of the stationary blade 7 is changed between the hub side and the tip side of the stationary blade 7 in the fifth embodiment, the pressure loss is reduced by reducing the secondary flow to the end wall, and the two-stage stationary blade 7 is closed. This is an example in which the performance improvement width is increased by locking, and the turbine efficiency can be further improved.

  FIG. 13 is a schematic diagram showing a relative positional relationship between a combustor tail cylinder and a first stage stationary blade, showing Embodiment 9 of the present invention. FIG. 13 is a side view of the combustion gas passage.

  This is because the axial position of the stationary blade 7 is changed between the hub side and the tip side of the stationary blade 7 in Embodiment 5 (see the chamfered portion 7d in the figure), and the pressure loss is reduced by reducing the secondary flow to the end wall. This is an example in which the performance improvement width is increased by clocking at the two-stage stationary blade 7, and the turbine efficiency can be further improved.

It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 1 of this invention. It is a principal part schematic block diagram of a gas turbine. It is comparison explanatory drawing of the effect | action by the relative position of a combustor tail cylinder and a 1st stage stationary blade. It is a graph which shows the relative position of a combustor tail cylinder and a 1st stage stationary blade preferable from a viewpoint of performance and cooling. It is the graph which analyzed the relationship between the relative position of a combustor tail cylinder and a 1st stage stationary blade, and efficiency. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 2 of this invention. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 3 of this invention. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 4 of this invention. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 5 of this invention. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 6 of this invention. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder which shows Example 7 of this invention, a 1st stage stationary blade, and a 2nd stage stationary blade. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 8 of this invention. It is a schematic diagram which shows the relative positional relationship of the combustor tail cylinder and the 1st stage stationary blade which show Example 9 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustor 2 Combustor inner cylinder 3 Fuel nozzle 4 Air compressor 5 Combustor tail cylinder 6 Turbine 7 Stator blade 7a Pressure surface 7b Negative pressure surface 7c Blade front edge 7d Chamfer 8 Rotor 9 Car compartment 10 Bypass valve 11 Bypass pipe 12 Wake flow

Claims (4)

  Fuel is combusted with compressed air from a compressor in a plurality of combustors arranged around the rotating shaft, and the combustion gas generated thereby flows into the turbine inlet from each combustor tail tube and burns in the turbine. Wake formed between adjacent combustor tail tubes in a gas turbine that generates power by sequentially passing a plurality of turbine stages including a plurality of stationary blades and moving blades arranged in a circumferential direction of a gas passage portion A communication structure between a combustor tail cylinder and a turbine inlet, wherein the combustor tail cylinder and the turbine inlet are connected so as to allow the flow to flow into the pressure surface side near the front edge of the first stage stationary blade.   2. A communication structure between a combustor tail cylinder and a turbine inlet according to claim 1, wherein the wake flow is caused to flow from a leading edge of the first stage stationary blade into a range of a quarter pitch of the first stage stationary blade.   3. The combustor tail cylinder according to claim 1, wherein a relative positional relationship between the wake flow and the first stage stationary blade is maintained without distributing a front edge position of the first stage stationary blade in a circumferential direction in a height direction. Communication structure with turbine inlet.   The combustor tail cylinder according to claim 1 or 2, wherein a circumferential position of the side surface of the tail cylinder is distributed in accordance with a front edge position of the first stage stator blade to maintain a relative positional relationship between the wake flow and the first stage stator blade. Communication structure between turbine and turbine inlet.

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