A multi-section TRT stator blade inner casing

Abstract

The present invention relates to a multi-section TRT stator blade inner casing, comprising a first-stage air intake section, a first-stage expansion section, a second-stage air intake section and a second-stage expansion section which are coaxially arranged and connected in sequence, a first arc section which can match with the spherical surface of the first-stage stator blade is arranged on the circumference of the first-stage air intake section, and a second arc section which can match with the spherical surface of the second-stage stator blade is arranged on the circumference of the second-stage air intake section. The stator blade inner casing of the present invention adopts a multi-section structural design, so that each stage of the TRT stator blade has an expansion angle that matches it; by setting the first arc section of the first-stage air intake section to match with the spherical surface of the first-stage stator blade, and the second arc section of the second-stage air intake section to match with the spherical surface of the second-stage stator blade, on the one hand, the problem of excessive radial clearance between the TRT stator blade body and the inner casing is solved, and the efficiency of the whole machine is improved; on the other hand, the chamfering of the stator blade mounting hole is facilitated, and the processing efficiency is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of blade-type rotation, and in particular relates to a multi-section TRT stator blade inner casing. Background Art

[0002] The Top Gas Pressure Recovery Turbine (TRT) is a device that uses the thermal energy and pressure energy of the blast furnace gas to produce work through a turbine. The device is mainly composed of a rotor, a casing, a stator inner casing, an inlet and exhaust guide basin, a moving and stationary blade, components and an adjustment mechanism. Among them, the stator inner casing is one of the important components that affect the power of the whole machine.

[0003] Traditional stationary blade inner casing usually adopts a single cone section design, such as Figure 1 As shown, the entire gas expansion work channel is divided into only two parts: the inlet straight section a and the single expansion section b, where the single expansion section b is usually set after the first-stage stationary blade c. This design method is convenient for processing, but the expansion angles of each stage must be kept consistent, resulting in a decrease in the matching of the blade profile and the expansion angle of each stage, and the radial clearance of the second-stage stationary blade d on the inner shell side is too large, which reduces the overall unit efficiency; and the second-stage stationary blade d is a conical surface, and the inner chamfer cannot be machined and can only be polished manually, which reduces the processing efficiency. Summary of the invention

[0004] In order to solve some or all of the above problems, the present invention provides a multi-section TRT stator blade inner casing, which solves the problems that the expansion angle of the expansion section of the traditional TRT stator blade inner casing is single, the blade profile of each stage can only match a single expansion angle, the radial clearance of the secondary stator blade on the inner casing side is too large, and the inner chamfer of the secondary stator blade mounting hole is inconvenient to process, which facilitates processing and greatly improves the efficiency of the entire unit.

[0005] The present invention provides a multi-section TRT stator blade inner casing, comprising a first-stage air intake section, a first-stage expansion section, a second-stage air intake section and a second-stage expansion section which are coaxially arranged and sequentially connected, wherein a first arc section which can cooperate with the spherical surface of the first-stage stator blade is arranged on the circumference of the first-stage air intake section, and a second arc section which can cooperate with the spherical surface of the second-stage stator blade is arranged on the circumference of the second-stage air intake section.

[0006] Furthermore, the first-stage air inlet section also includes a first equal-diameter section connected to the air inlet side of the first circular arc section and a second equal-diameter section connected to the air outlet side of the first circular arc section, and the second-stage air inlet section also includes a third equal-diameter section connected to the air inlet side of the second circular arc section and a fourth equal-diameter section connected to the air outlet side of the second circular arc section.

[0007] Furthermore, the first-stage air intake section also includes a first mounting hole connected to the first circular arc section and used for installing the first-stage stationary blade, and the second-stage air intake section also includes a second mounting hole connected to the second circular arc section and used for installing the second-stage stationary blade.

[0008] Furthermore, the arc center of the first arc segment is located on the central axis of the first-stage air intake segment, and the arc center of the second arc segment is located on the central axis of the second-stage air intake segment.

[0009] Furthermore, the inner diameter of the first equal-diameter section is equal to the inner diameter of the second equal-diameter section, and the inner diameter of the third equal-diameter section is equal to the inner diameter of the fourth equal-diameter section.

[0010] Furthermore, the length of the first equal-diameter section is equal to the length of the second equal-diameter section, and the length of the third equal-diameter section is equal to the length of the fourth equal-diameter section.

[0011] Furthermore, the first mounting hole is vertically connected to the midpoint of the first arc segment, and the second mounting hole is vertically connected to the midpoint of the second arc segment.

[0012] Furthermore, the arc radius of the second arc segment is greater than the arc radius of the first arc segment.

[0013] Furthermore, an angle between the secondary diameter expansion section and the fourth equal diameter section is greater than an angle between the primary diameter expansion section and the second equal diameter section.

[0014] Furthermore, the included angle between the secondary diameter expansion section and the fourth equal diameter section is between 13° and 15°, and the included angle between the primary diameter expansion section and the second equal diameter section is between 7° and 13°.

[0015] The stator blade inner casing of the present invention adopts a multi-section structural design, so that each level of TRT stator blade has an expansion angle that matches it; by setting the first arc segment of the first-stage air intake segment to match the spherical surface of the first-stage stator blade, and the second arc segment of the second-stage air intake segment to match the spherical surface of the second-stage stator blade, on the one hand, the problem of excessive radial clearance between the TRT stator blade body and the inner casing is solved, thereby improving the efficiency of the entire machine; on the other hand, it also facilitates the chamfering of the stator blade mounting hole, thereby effectively improving the processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0017] Figure 1It is a schematic diagram of the structure of the inner casing of a conventional TRT stator blade in the prior art;

[0018] Figure 2 It is a schematic structural diagram of a multi-section TRT stator blade inner casing shown in an embodiment of the present invention.

[0019] Explanation of the accompanying drawings: multi-section TRT stator blade inner casing 100, first-stage air intake section 1, first circular arc section 101, first equal diameter section 102, second equal diameter section 103, first mounting hole 104, first-stage expanded diameter section 2, second-stage air intake section 3, second circular arc section 301, third equal diameter section 302, fourth equal diameter section 303, second mounting hole 304, second-stage expanded diameter section 4, first-stage stator blade 5, second-stage stator blade 6. DETAILED DESCRIPTION

[0020] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0021] like Figure 2 As shown, this embodiment provides a multi-section TRT stator blade inner casing, including a first-stage air intake section 1, a first-stage expansion section 2, a second-stage air intake section 3 and a second-stage expansion section 4 which are coaxially arranged and sequentially connected, and a first arc section 101 which can cooperate with the spherical surface of the first-stage stator blade 5 is arranged on the circumference of the first-stage air intake section 1, and a second arc section 301 which can cooperate with the spherical surface of the second-stage stator blade 6 is arranged on the circumference of the second-stage air intake section 3.

[0022] The stator blade inner shell of this embodiment adopts a multi-section structural design, so that each level of TRT stator blade has a matching expansion angle; by setting the first arc segment 101 of the first-stage air intake section 1 to match the spherical surface of the first-stage stator blade 5, and the second arc segment 301 of the second-stage air intake section 3 to match the spherical surface of the second-stage stator blade 6, compared with the traditional stator blade inner shell, the second-stage stator blade mounting hole is directly set on the expansion section, which cannot meet the spherical surface matching of the second-stage stator blade, resulting in a significant gap between the second-stage stator blade on the inner shell side. This embodiment solves the problem of excessive radial clearance between the TRT stator blade body and the inner shell by setting the second arc segment of the second-stage air intake section to match the spherical surface of the second-stage stator blade, thereby improving the efficiency of the entire machine. In addition, it also solves the problem of difficult manual grinding of the inner chamfer of the traditional second-stage stator blade installation. The spherical surface matching design of the second-stage stator blade installation facilitates the chamfering of the stator blade mounting hole, effectively improving the processing efficiency.

[0023] In this embodiment, the first-stage air inlet section 1 further includes a first equal-diameter section 102 connected to the air inlet side of the first arc section 101 and a second equal-diameter section 103 connected to the air outlet side of the first arc section 101, and the second-stage air inlet section 3 further includes a third equal-diameter section 302 connected to the air inlet side of the second arc section 301 and a fourth equal-diameter section 303 connected to the air outlet side of the second arc section 301. By respectively arranging equal-diameter sections on both sides of the first arc section 101\the second arc section 301 for mounting the stationary blades, the installation tightness of the stationary blades on the inner side of the inner casing is effectively guaranteed. Compared with the structural design in which the second-stage stationary blades 6 are arranged on the expanded diameter section in the prior art, the problem of low overall unit efficiency due to excessive clearance of the second-stage stationary blades 6 on the inner side of the inner casing is solved.

[0024] In a preferred embodiment, the inner diameter of the first equal diameter section 102 is equal to the inner diameter of the second equal diameter section 103, and the inner diameter of the third equal diameter section 302 is equal to the inner diameter of the fourth equal diameter section 303. The spacing between the first equal diameter section and the central axis is equal to the spacing between the second equal diameter section and the central axis, thereby ensuring the symmetry of the connection between the two ends of the first arc section and the first and second equal diameter sections 102 and 103, and ensuring the tightness of the installation of the first-stage stationary blade 5 inside the first arc section of the first-stage air intake section 1; similarly, the spacing between the third equal diameter section and the central axis is equal to the spacing between the fourth equal diameter section and the central axis, thereby ensuring the symmetry of the connection between the two ends of the second arc section and the third and fourth equal diameter sections 302 and 303, and ensuring the tightness of the installation of the second-stage stationary blade 6 inside the second arc section of the second-stage air intake section 3.

[0025] In a preferred embodiment, the length of the first equal diameter section 102 is equal to the length of the second equal diameter section 103, and the length of the third equal diameter section 302 is equal to the length of the fourth equal diameter section 303. The first-stage stationary blade 5 is installed at the center of the first air intake section, and the second-stage stationary blade 6 is installed at the center of the second air intake section, which is conducive to ensuring the installation stability of the first-stage stationary blade 5 and the second-stage stationary blade 6 and the flow stability of the gas.

[0026] In the multi-section TRT stator inner casing of the present embodiment, the first-stage air intake section 1 further includes a first mounting hole 104 which is connected to the first arc section 101 and is used to install the first-stage stator 5, and the second-stage air intake section 3 further includes a second mounting hole 304 which is connected to the second arc section 301 and is used to install the second-stage stator 6. The first-stage stator 5 is fixedly mounted through the first mounting hole 104 so that the spherical surface of the first-stage stator 5 matches the spherical surface of the first arc section 101 of the first air intake section, and the deflection angle of the first-stage stator 5 is adjusted by adjusting the assembly angle between the first-stage stator 5 and the first mounting hole 104. Similarly, the second-stage stator 6 is fixedly mounted through the second mounting hole 304 so that the spherical surface of the second-stage stator 6 matches the spherical surface of the second arc section 301 of the second air intake section, and the deflection angle of the second-stage stator 6 is adjusted by adjusting the assembly angle between the second-stage stator 6 and the second mounting hole 304.

[0027] In a preferred embodiment, the arc center of the first arc segment 101 is located on the central axis of the first-stage air intake segment 1, and the arc center of the second arc segment 301 is located on the central axis of the second-stage air intake segment 3. It is possible to make the multiple first-stage stationary blades 5 installed on the first air intake segment face the central axis of the inner shell, and it is also possible to make the multiple second-stage stationary blades 6 installed on the second air intake segment face the central axis of the inner shell. The consistency of the arrangement of the first-stage stationary blades 5 and the second-stage stationary blades 6 is ensured. Since there is an expansion section between the first-stage air intake segment 1 and the second-stage air intake segment 3, the inner diameter of the second-stage air intake segment 3 is larger than the inner diameter of the first-stage air intake segment 1, which makes the arc radius of the second arc segment 301 larger than the arc radius of the first arc segment 101 in the multi-stage TRT stationary blade inner shell of this embodiment. The size of the arc radius is usually determined by the size of the main engine. In a specific embodiment, the arc radius of the first arc segment 101 is 400mm~900mm, and the arc radius of the second arc segment 301 is 450mm~1000mm.

[0028] In a preferred embodiment, the first mounting hole 104 is vertically connected to the arc midpoint of the first arc segment 101, and the second mounting hole 304 is vertically connected to the arc midpoint of the second arc segment 301. This ensures that the stationary blades can face the central axis of the inner casing at any deflection angle.

[0029] In this embodiment, the angle between the secondary expansion section 4 and the fourth equal diameter section 303 is greater than the angle between the primary expansion section 2 and the second equal diameter section 103. Since the expansion ratios and aerodynamic load coefficients of the blades at each level are different, the optimal expansion angles corresponding to the blades at each level should also be different. This embodiment provides different expansion angles for the primary expansion section 2 and the secondary expansion section 4 to meet the expansion angle requirements of different blades. The specific angle is determined according to the actual project parameters. Compared with the unified expansion angle design of the traditional TRT stator inner shell, the efficiency of the entire unit is effectively improved.

[0030] In a specific embodiment, in the first-stage air intake section 1, the starting point B of the first arc segment 101 is set at about 50 to 400 mm behind the air flow inlet A, the end point of the first arc segment 101 is located at D, the center of the first arc segment 101 is located at the center of the main shaft, and the first mounting hole 104 for mounting the first-stage stationary blade 5 is located at the midpoint C of the first arc segment 101.

[0031] The first-stage diameter expansion section 2 is located after the first-stage air intake section 1, and its axial dimension is preferably 100-600 mm, wherein the angle between the first-stage diameter expansion section 2 and the second equal diameter section 103 is 7°-13°.

[0032] In the secondary air inlet section 3, the starting point G of the second arc section 301 is set at about 50 to 300 mm behind the airflow inlet F, the end point of the second arc section 301 is located at I, the center of the second arc section 301 is located at the center of the main shaft, and the second mounting hole 304 for mounting the secondary stator blade 6 is located at the midpoint H of the second arc section 301. The radius of the second arc section 301 is determined by the size of the main engine. In this embodiment, the radius of the second arc section 301 is preferably 450 mm to 1000 mm, and the radius of the second arc section 301 is greater than the radius of the first arc section 101.

[0033] The secondary diameter expansion section 4 is located after the secondary air intake section 3 , and the included angle between the secondary diameter expansion section 4 and the fourth equal diameter section 303 is 13-15°, which is generally greater than the included angle between the primary diameter expansion section 2 and the second equal diameter section 103 .

[0034] The multi-stage TRT stator blade inner casing in this embodiment solves the disadvantage that the expansion angles corresponding to the blades of each stage are consistent due to the traditional stator blade inner casing having only one expansion section, by matching the optimal expansion angle for each stage and setting a second arc section that matches the spherical surface of the second-stage stator blade 6 in the second-stage air intake section. This not only improves the convenience of processing, but also significantly improves the operating efficiency of the unit. For conventional TRT, after adopting this invention patent, the efficiency of the whole machine can be improved by 1-2% on the original basis.

[0035] In the description of the present application, it should be understood that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A multi-section TRT stator blade inner casing, characterized in that: It includes a first-stage air intake section, a first-stage expansion section, a second-stage air intake section and a second-stage expansion section which are coaxially arranged and connected in sequence, wherein the first-stage air intake section is provided with a first arc section which can match with the spherical surface of the first-stage stationary blade in the circumferential direction, and the second-stage air intake section is provided with a second arc section which can match with the spherical surface of the second-stage stationary blade in the circumferential direction; the second-stage air intake section also includes a third equal-diameter section connected to the air intake side of the second arc section and a fourth equal-diameter section connected to the air outlet side of the second arc section, and the inner diameter of the third equal-diameter section is equal to the inner diameter of the fourth equal-diameter section; the first-stage air intake section also includes a first equal-diameter section connected to the air intake side of the first arc section and a second equal-diameter section connected to the air outlet side of the first arc section; the first-stage air intake section also includes a first mounting hole which is connected to the first arc section and is used to install the first-stage stationary blade, and the second-stage air intake section also includes a second mounting hole which is connected to the second arc section and is used to install the second-stage stationary blade.

2. The multi-section TRT stator blade inner casing according to claim 1 is characterized in that: The arc center of the first arc segment is located on the central axis of the first-stage air intake segment, and the arc center of the second arc segment is located on the central axis of the second-stage air intake segment.

3. The multi-section TRT stator blade inner casing according to claim 1 is characterized in that: The inner diameter of the first equal-diameter section is equal to the inner diameter of the second equal-diameter section.

4. The multi-section TRT stator blade inner casing according to claim 1 is characterized in that: The length of the first equal-diameter section is equal to the length of the second equal-diameter section, and the length of the third equal-diameter section is equal to the length of the fourth equal-diameter section.

5. The multi-section TRT stator blade inner casing according to claim 1, characterized in that: The first mounting hole is vertically connected to the midpoint of the first arc segment, and the second mounting hole is vertically connected to the midpoint of the second arc segment.

6. The multi-section TRT stator blade inner casing according to claim 1, characterized in that: The arc radius of the second arc segment is greater than the arc radius of the first arc segment.

7. The multi-section TRT stator blade inner casing according to claim 1, characterized in that: The included angle between the secondary diameter expansion section and the fourth equal diameter section is greater than the included angle between the primary diameter expansion section and the second equal diameter section.

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