Wheel disk cooling mechanism for single-stage flue gas turbine and single-stage flue gas turbine

Abstract

The present invention discloses a wheel cooling mechanism for a single-stage flue gas turbine and a single-stage flue gas turbine, belonging to the technical field of petrochemical equipment. The wheel cooling mechanism includes a wheel and a sealing component, a plurality of guide holes are arranged on the wheel, each guide hole runs through the front and rear sides of the wheel, the sealing component can perform annular sealing on the gap between the wheel and the stationary blade assembly, and the sealing component surrounds the opening position of each guide hole on the front side of the wheel. The present invention arranges a sealing component between the wheel and the stationary blade assembly, and arranges a plurality of guide holes running through the front and rear sides of the wheel on the wheel, so that when the center position of the wheel is cooled by cooling steam, the cooling steam can be transported to the rear side of the wheel along the plurality of guide holes, thereby avoiding the cooling steam from being transported to the space between the stationary blade assembly and the moving blades, thereby avoiding the cooling steam from blocking the high-temperature flue gas and reducing the effective flow area of ​​the high-temperature flue gas.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical equipment, and in particular to a wheel disc cooling mechanism for a single-stage flue gas turbine and the single-stage flue gas turbine. Background Art

[0002] The flue gas turbine is a key equipment of the catalytic cracking unit of the refinery. It is mainly used to recover the heat in the high-temperature flue gas generated when the catalytic cracking unit is burned, thereby reducing energy consumption and improving economic benefits. Among them, the flue gas turbine mainly includes a main shaft, a wheel, moving blades, a stationary blade assembly and a shroud. The high-temperature flue gas can be sprayed to the moving blades under the action of the stationary blade assembly to cause the moving blades to rotate, thereby converting the thermal energy of the high-temperature flue gas into the mechanical energy of the moving blades. After that, the moving blades drive the wheel and the main shaft to rotate synchronously, so that the load equipment can be driven to rotate through the main shaft to realize the recovery of heat in the high-temperature flue gas.

[0003] During the heat recovery process, high temperature will be generated at the center of the wheel, which will create certain safety hazards. Therefore, cooling steam can be sprayed to the center of the side of the wheel facing the stator assembly (the front side of the wheel) to cool the wheel and improve the safety of the flue gas turbine operation.

[0004] However, designers found that after cooling the center of the impeller, the cooling steam moves radially around the impeller and to the space between the stationary blade assembly and the moving blades. On the one hand, the cooling steam can block the high-temperature flue gas and form a local vortex at the connection between the moving blades and the impeller, causing erosion to the roots of the moving blades. On the other hand, the cooling steam can occupy part of the flow area, thereby reducing the effective flow area of ​​the high-temperature flue gas and cooling the high-temperature flue gas at the same time, thereby reducing the heat recovery rate. On the other hand, the cooling steam can promote scaling of the inner wall of the belt wrapping the stationary blade assembly and the moving blades, thereby reducing the safety of the flue gas turbine operation. Summary of the invention

[0005] The present invention provides a wheel cooling mechanism for a single-stage flue gas turbine and a single-stage flue gas turbine, which can solve the problem of erosion at the root of the moving blades and low energy recovery rate of high-temperature flue gas. The technical solution is as follows:

[0006] In a first aspect, the present invention provides a wheel disk cooling mechanism for a single-stage flue gas turbine, comprising a wheel disk, the wheel disk cooling mechanism further comprising a sealing member;

[0007] The wheel disc is provided with a plurality of guide holes, each of which passes through the front and rear sides of the wheel disc. The sealing component can perform annular sealing on the gap between the wheel disc and the stationary blade assembly, and the sealing component surrounds the opening position of each guide hole on the front side of the wheel disc.

[0008] In a possible implementation, the sealing member is an annular structure with a preset thickness, one end of the sealing member is used to be fixedly connected to the stationary blade assembly, and the end face of the other end of the sealing member can be honeycombed with the front end face of the wheel disc.

[0009] Optionally, the wheel disc cooling mechanism further comprises a wheel disc spoke plate;

[0010] The wheel disc spoke plate and the sealing component are both cylindrical structures with holes at both ends. One end of the wheel disc spoke plate is fixedly connected to the front side of the wheel disc, one end of the sealing component is used to be fixedly connected to the stationary blade assembly, and the other end of the wheel disc spoke plate can be honeycombed sealed with the other end of the sealing component.

[0011] Optionally, the outer wall of the wheel disc spoke can be honeycomb-sealed with the inner wall of the sealing member, or the inner wall of the wheel disc spoke can be honeycomb-sealed with the outer wall of the sealing member.

[0012] Optionally, the straight line where each guide hole is located is parallel to the center line of the wheel disc.

[0013] Optionally, the straight line where each guide hole is located is toward the center line of the wheel disc in the direction from the front side of the wheel disc to the rear side of the wheel disc.

[0014] Optionally, each guide hole is evenly distributed along the circumferential direction at an opening position on the front side of the wheel disc.

[0015] Optionally, the distance between the opening position of each guide hole located on the front side of the wheel disc and the center position of the wheel disc is 0.25 times the diameter of the wheel disc.

[0016] In a second aspect, the present invention provides a single-stage flue gas turbine, which is provided with a wheel disc cooling mechanism as described in the first aspect above.

[0017] The beneficial effects of the technical solution provided by the present invention include at least:

[0018] The present invention provides a sealing member between the impeller and the stationary blade assembly, and provides a plurality of guide holes on the impeller that penetrate the front and rear sides of the impeller. Thus, when the center of the impeller is cooled by cooling steam, the cooling steam can be transported to the rear side of the impeller along the plurality of guide holes because the sealing member surrounds the opening position of each guide hole on the front side of the impeller, thereby avoiding the cooling steam from being transported to the space between the stationary blade assembly and the moving blades, thereby avoiding the cooling steam from blocking the high-temperature flue gas, occupying the effective flow area of ​​the high-temperature flue gas, and reducing the safety of the single-stage flue gas turbine operation due to the scaling of the inner wall of the belt. In addition, when the cooling steam is transported along the rear side of the impeller to the rear side of the moving blade, the flue gas on the rear side of the moving blade can be cooled, thereby reducing the flue gas pressure on the rear side of the moving blade, facilitating the high-temperature flue gas on the front side of the moving blade to push the moving blade, and improving the energy recovery rate in the high-temperature flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 is a schematic cross-sectional structure diagram of a single-stage flue gas turbine provided with a wheel cooling mechanism provided in an embodiment of the present invention;

[0021] Figure 2 It is a schematic cross-sectional structure diagram of a single-stage flue gas turbine provided with another wheel cooling mechanism provided in an embodiment of the present invention.

[0022] Reference numerals:

[0023] 1: wheel disc; 11: guide hole; 2: sealing component; 3: stationary blade assembly; 4: wheel disc spoke plate; 5: moving blade. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] Figure 1 The schematic diagram of the structure of a single-stage flue gas turbine provided with a wheel cooling mechanism according to an embodiment of the present invention is illustrated. Figure 1As shown, the single-stage flue gas turbine also includes a stationary blade assembly 3 and a moving blade 5, and the wheel cooling mechanism includes a wheel 1 and a sealing component 2. The wheel 1 is provided with a plurality of guide holes 11, and each guide hole 11 passes through the front and rear sides of the wheel 1. The sealing component 2 can perform annular sealing on the gap between the wheel 1 and the stationary blade assembly 3, and the sealing component 2 surrounds the opening position of each guide hole 11 on the front side of the wheel 1.

[0026] In the embodiment of the present invention, a sealing member 2 is provided between the wheel disc 1 and the stationary blade assembly 3, and a plurality of guide holes 11 are provided on the wheel disc 1 that penetrate the front and rear sides of the wheel disc 1. Thus, when the center position of the wheel disc 1 is cooled by cooling steam, the cooling steam can be transported to the rear side of the wheel disc 1 along the plurality of guide holes 11 because the sealing member 2 surrounds the opening position of each guide hole 11 on the front side of the wheel disc 1, thereby avoiding the cooling steam from being transported to the space between the stationary blade assembly 3 and the moving blade 5, thereby avoiding the cooling steam from blocking the high-temperature flue gas, occupying the effective flow area of ​​the high-temperature flue gas, and reducing the safety of the operation of the single-stage flue gas turbine by promoting the scaling phenomenon on the inner wall of the shroud. In addition, when the cooling steam is transported along the rear side of the wheel disc 1 to the rear side of the moving blade 5, the flue gas on the rear side of the moving blade 5 can be cooled, thereby reducing the flue gas pressure on the rear side of the moving blade 5, facilitating the high-temperature flue gas on the front side of the moving blade 5 to push the moving blade 5, and improving the energy recovery rate in the high-temperature flue gas.

[0027] The wheel disc 1 may include a wheel rim, a wheel surface and a wheel hub. The wheel rim is used to be fixedly connected with the moving blade 5, and the sealing member 2 may perform annular sealing on the gap between the wheel rim and the stationary blade assembly 3. Of course, the sealing member 2 may also perform annular sealing on the gap between the wheel surface and the stationary blade assembly 3. The wheel surface is used to fix the wheel rim and the wheel hub as a whole, and the plurality of guide holes 11 may be through holes arranged on the wheel surface. The wheel hub is used to be fixedly connected with the main shaft of the single-stage flue gas turbine. The wheel hub and the main shaft may be fixedly connected by positioning the stopper and pre-tightening the tie rod bolts. The sealing member 2 may be composed of a sealing member and a honeycomb belt, so that the annular seal between the wheel disc 1 and the stationary blade assembly 3 may be achieved by honeycomb sealing under the action of the honeycomb belt. Of course, the sealing member 2 may also achieve annular sealing between the wheel disc 1 and the stationary blade assembly 3 in other forms. For example, the end face used for sealing on the sealing member 2 may be a comb-tooth structure, so as to achieve annular sealing between the wheel disc 1 and the stationary blade assembly 3 by comb-tooth sealing.

[0028] Among them, when the guide holes 11 are arranged on the wheel disc 1, the opening position of each guide hole 11 on the front side of the wheel disc 1 can be evenly distributed along the circumferential direction. Of course, the opening position of each guide hole 11 on the front side of the wheel disc 1 can also be distributed along a spiral shape, which is not limited in the embodiment of the present invention. The distance between the opening position of each guide hole 11 on the front side of the wheel disc 1 and the center position of the wheel disc 1 can be 0.25 times the diameter of the wheel disc 1, so that after a plurality of guide holes 11 are arranged, the safety of the operation of the wheel disc 1 can be ensured. Of course, the ratio between the distance between the opening position of each guide hole 11 on the front side of the wheel disc 1 and the center position of the wheel disc 1 and the diameter of the wheel disc 1 can be other values, which is not limited in the embodiment of the present invention.

[0029] In the embodiment of the present invention, as shown in the attached Figure 1 As shown, the sealing member 2 is an annular structure with a preset thickness. The preset thickness of the sealing member 2 can be determined based on the distance between the wheel disc 1 and the stationary blade assembly 3. The specific determination of the preset thickness of the sealing member 2 can refer to the prior art, and the embodiment of the present invention does not limit this. The sealing member and the honeycomb belt included in the sealing member 2 are both annular structures, and the sum of the thickness of the sealing member and the honeycomb belt is the preset thickness of the sealing member 2.

[0030] When the gap between the wheel disc 1 and the stationary blade assembly 3 is annularly sealed by the sealing member 2, in a possible implementation, one end of the sealing member 2 is used to be fixedly connected to the stationary blade assembly 3, and the end face of the other end of the sealing member 2 can be honeycomb-sealed with the front end face of the wheel disc 1. That is, when the wheel disc cooling mechanism is installed on the single-stage flue gas turbine, one end of the sealing member 2 can be fixedly connected to one end of the stationary blade assembly 3 close to the front side of the wheel disc 1, so as to achieve the annular sealing between the wheel disc 1 and the stationary blade assembly 3 by the sealing member 2, and at the same time achieve the relative rotation between the sealing member 2 and the wheel disc 1. In this way, after the cooling steam cools the central position of the front side of the wheel disc 1, it can be prevented that the cooling steam moves along the gap between the sealing member 2 and the stationary blade assembly 3 and / or the gap between the sealing member 2 and the wheel disc 1 to the space between the stationary blade assembly 3 and the moving blade 5, thereby avoiding the corrosion formed on the root of the moving blade 5, increasing the effective flow area of ​​the high-temperature flue gas, and also improving the safety of the operation of the single-stage flue gas turbine.

[0031] Among them, one end of the sealing member 2 and one end of the stationary blade assembly 3 close to the front side of the wheel disc 1 can be fixedly connected in a non-detachable manner, such as by welding or an integrated design. Of course, one end of the sealing member 2 and one end of the stationary blade assembly 3 close to the front side of the wheel disc 1 can also be fixedly connected in a detachable manner, such as one end of the sealing member 2 can be fixed to the stationary blade assembly 3 by screw connection or threaded connection, so that when the gap between the stationary blade assembly 3 and the wheel disc 1 is not tightly sealed, it is convenient to replace the sealing member 2, and the embodiment of the present invention does not limit this.

[0032] Of course, in another possible implementation, one end of the sealing member 2 is fixedly connected to the front side of the wheel disc 1, and the end face of the other end of the sealing member 2 can be honeycombed with the end face of the stator blade assembly 3 near the front side of the wheel disc 1. That is, when the wheel disc cooling mechanism is installed on the single-stage flue gas turbine, the other end of the sealing member 2 can be honeycombed with the end face of the stator blade assembly 3 near the front side of the wheel disc 1, thereby realizing the annular sealing between the wheel disc 1 and the stator blade assembly 3 by the sealing member 2, and realizing the relative rotation between the sealing member 2 and the stator blade assembly 3. In this way, after the cooling steam cools the central position of the front side of the wheel disc 1, it can be prevented that the cooling steam moves along the gap between the sealing member 2 and the stator blade assembly 3 and / or the gap between the sealing member 2 and the wheel disc 1 to the space between the stator blade assembly 3 and the moving blade 5, thereby avoiding the corrosion formed on the root of the moving blade 5, occupying the effective flow area of ​​the high-temperature flue gas, and improving the safety of the operation of the single-stage flue gas turbine.

[0033] Among them, one end of the sealing member 2 and the front end face of the wheel disc 1 can be fixedly connected in a non-detachable manner, for example, the non-detachable connection between the sealing member 2 and the stationary blade assembly 3 can be achieved by welding or an integrated design. Of course, one end of the sealing member 2 and the front end face of the wheel disc 1 can also be fixedly connected in a detachable manner, for example, one end of the sealing member 2 can be fixed to the stationary blade assembly 3 by screw connection, so that when the gap between the stationary blade assembly 3 and the wheel disc 1 is not tightly sealed, it is convenient to replace the sealing member 2, and the embodiment of the present invention does not limit this.

[0034] In the embodiment of the present invention, as shown in the attached Figure 2 As shown, the wheel disk cooling mechanism also includes a wheel disk spoke plate 4. Both the wheel disk spoke plate 4 and the sealing component 2 are cylindrical structures with holes at both ends. One end of the wheel disk spoke plate 4 is fixedly connected to the front side of the wheel disk 1, and one end of the sealing component 2 is used to be fixedly connected to the stationary blade assembly 3. The other end of the wheel disk spoke plate 4 can be honeycomb-sealed with the other end of the sealing component 2.

[0035] Among them, the wheel disc 1 and the wheel disc spoke 4 can also be designed as an integrated body, which is not limited in the embodiment of the present invention. When the wheel disc spoke 4 is fixedly connected to the front side of the wheel disc 1, the wheel disc spoke 4 can be put on the rim of the wheel disc 1, and the fixed connection can be achieved by the non-detachable or detachable manner described above, which is not limited in the embodiment of the present invention. The fixed connection between one end of the sealing component 2 and the stationary blade assembly 3 can be as described above, which is not repeated in the embodiment of the present invention. The sealing component 2 includes a seal and a honeycomb belt, both of which are cylindrical structures with holes at both ends.

[0036] Among them, in order to realize that the other end of the wheel disc spoke 4 can be honeycomb-sealed with the other end of the sealing member 2, in a possible implementation, the other end of the sealing member 2 can be sleeved on the other end of the wheel disc spoke 4 to realize honeycomb sealing between the inner wall of the sealing member 2 and the outer wall of the wheel disc spoke 4, and at this time, the sealing member is sleeved on the honeycomb belt. Of course, in a possible implementation of the other end, the other end of the wheel disc spoke 4 can be sleeved on the other end of the sealing member 2 to realize honeycomb sealing between the outer wall of the sealing member 2 and the inner wall of the wheel disc spoke 4, and at this time, the honeycomb belt is sleeved on the sealing member.

[0037] In the embodiment of the present invention, when the guide holes 11 are arranged on the wheel disc 1, each guide hole 11 may be a straight line, and the straight line where each guide hole 11 is located may be parallel to the center line of the wheel disc 1. Of course, the straight line where each guide hole 11 is located may also be toward the center line of the wheel disc 1 in the direction from the front side of the wheel disc 1 to the rear side of the wheel disc 1.

[0038] The cooling steam can be transported from the front side of the wheel disc 1 to the rear side of the wheel disc 1 along the guide holes 11, and then directly transported radially from the opening position of each guide hole 11 on the rear side of the wheel disc 1 to the rear side of the moving blade 5 during the rotation of the wheel disc 1. When the straight line where each guide hole 11 is located is facing the center line of the wheel disc 1 in the direction from the front side of the wheel disc 1 to the rear side of the wheel disc 1, the opening position of each guide hole 11 on the rear side of the wheel disc 1 is close to the center position of the wheel disc 1, so that the cooling steam that moves to the rear side of the wheel disc 1 along the guide holes 11 can cool the wheel disc 1 again from the center position of the wheel disc 1, thereby improving the cooling efficiency of the wheel disc 1. In addition, the migration path of the cooling steam in the wheel disc 1 can also be extended, thereby extending the cooling time of the cooling steam on the wheel disc 1 and improving the cooling efficiency of the cooling steam.

[0039] Of course, each guide hole 11 may also be in a curved shape, which can extend the migration path of the cooling steam in the wheel disc 1, thereby extending the cooling time of the cooling steam on the wheel disc 1 and improving the cooling efficiency of the cooling steam. When each guide hole 11 is in a curved shape, the opening position of each guide hole 11 on the rear side of the wheel disc 1 may be close to the center position of the wheel disc 1, thereby ensuring that the cooling steam migrated to the rear side of the wheel disc 1 can cool the wheel disc 1 again at the center position of the wheel disc 1, thereby improving the cooling efficiency of the wheel disc 1.

[0040] In the embodiment of the present invention, a sealing member is provided between the impeller and the stationary blade assembly, and a plurality of guide holes penetrating the front and rear sides of the impeller are provided on the wheel surface of the impeller. Since the straight line where each guide hole is located is oriented toward the center line of the impeller in the direction from the front side of the impeller to the rear side of the impeller, the migration path of the cooling steam in the impeller can be extended, the cooling time of the cooling steam on the impeller can be extended, and the cooling effect of the cooling steam on the impeller can be improved. In addition, since the sealing member surrounds the opening position of each guide hole on the front side of the impeller, it is possible to prevent the cooling steam from migrating to the space between the stationary blade assembly and the moving blades, thereby avoiding the cooling steam from blocking the high-temperature flue gas, occupying the effective flow area of ​​the high-temperature flue gas, and reducing the safety of the operation of the single-stage flue gas turbine due to the promotion of scaling on the inner wall of the shroud.

[0041] An embodiment of the present invention provides a single-stage flue gas turbine, which mainly includes a main shaft, moving blades, a stationary blade assembly and a shroud, and the wheel cooling mechanism described in the above embodiment.

[0042] In the embodiment of the present invention, since the delayed turbine is installed with the wheel cooling mechanism described in the above embodiment, when the center position of the wheel is cooled by cooling steam, the cooling steam can be transported along the multiple guide holes to the rear side of the wheel due to the opening position of each guide hole on the front side of the wheel surrounding the sealing component, thereby avoiding the cooling steam from being transported to the space between the stationary blade assembly and the moving blades, thereby avoiding the obstruction of the high-temperature flue gas by the cooling steam, the reduction of the effective flow area of ​​the high-temperature flue gas, and the reduction of the safety of the operation of the single-stage flue gas turbine due to the promotion of scaling on the inner wall of the shroud.

[0043] The above description is only an illustrative embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wheel cooling mechanism for a single-stage flue gas turbine, comprising a wheel (1), characterized in that: The wheel disk cooling mechanism further comprises a sealing component (2); The wheel disc (1) is provided with a plurality of guide holes (11), each guide hole (11) penetrates the front side and the rear side of the wheel disc (1), and the opening positions of the plurality of guide holes (11) on the front side of the wheel disc (1) are evenly distributed in the circumferential direction. The sealing component (2) can perform an annular sealing on the gap between the wheel disc (1) and the stationary blade assembly (3), and the sealing component (2) surrounds the opening position of each guide hole (11) on the front side of the wheel disc (1), so that cooling steam can move along the plurality of guide holes (11) to the rear side of the wheel disc (1), and then directly move radially from the opening position of each guide hole (11) on the rear side of the wheel disc (1) to the rear side of the moving blade (5) during the rotation of the wheel disc (1), thereby preventing cooling steam from moving to the space between the stationary blade assembly (3) and the moving blade (5); The sealing component (2) is in the form of a circular ring structure with a preset thickness. One end of the sealing component (2) is used to be fixedly connected to one end of the stationary blade assembly (3) close to the front side of the wheel disc (1). The end face of the other end of the sealing component (2) can form a honeycomb seal with the front end face of the wheel disc (1), thereby achieving an annular seal between the wheel disc (1) and the stationary blade assembly (3) by the sealing component (2), and at the same time achieving relative rotation between the sealing component (2) and the wheel disc (1).

2. The wheel cooling mechanism according to claim 1, characterized in that: The wheel disk cooling mechanism also includes a wheel disk spoke plate (4); The wheel disc spoke (4) and the sealing member (2) are both cylindrical structures with holes at both ends; one end of the wheel disc spoke (4) is fixedly connected to the front side of the wheel disc (1); one end of the sealing member (2) is used to be fixedly connected to the stationary blade assembly (3); and the other end of the wheel disc spoke (4) can be honeycomb-sealed with the other end of the sealing member (2).

3. The wheel cooling mechanism according to claim 2, characterized in that: The outer wall of the wheel disc spoke (4) can form a honeycomb seal with the inner wall of the sealing member (2), or the inner wall of the wheel disc spoke (4) can form a honeycomb seal with the outer wall of the sealing member (2).

4. The wheel cooling mechanism according to any one of claims 1 to 3, characterized in that: The straight line where each guide hole (11) is located is parallel to the center line of the wheel disc (1).

5. The wheel cooling mechanism according to any one of claims 1 to 3, characterized in that: The straight line where each guide hole (11) is located faces the center line of the wheel disc (1) in the direction from the front side of the wheel disc (1) to the rear side of the wheel disc (1).

6. The wheel cooling mechanism according to claim 1, characterized in that: The distance between the opening position of each guide hole (11) located on the front side of the wheel disc (1) and the center position of the wheel disc (1) is 0.25 times the diameter of the wheel disc (1).

7. A single-stage flue gas turbine, characterized in that: The single-stage flue gas turbine is provided with a wheel disc cooling mechanism as described in any one of claims 1 to 6 above.

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