Circumferentially mounted turbine blade locking structure and mounting method thereof

Abstract

The invention discloses a circumferentially-mounted turbine blade locking structure and a mounting method thereof, and relates to the field of turbine equipment in the energy power industry. The problems that an existing wheel-drum-type rotor is not provided with a wheel disc, locking movable blades cannot be fixed in an axial pin hitting mode, and circumferential installation blades of the wheel-drum-type rotor cannot be suitable for a small axial size limited compact steam turbine are solved. A plurality of blades are evenly arranged in a rotor wheel groove in the circumferential direction, a blade mounting window is machined in the rotor wheel groove, a blade locking piece is of a split structure and comprises a left blade locking block and a right blade locking block, and the left blade locking block and the right blade locking block are arranged in the blade mounting window. The thrust wedge is vertically arranged between the left blade locking block and the right blade locking block, and the left blade locking block and the right blade locking block are connected with the rotor through the thrust wedge. The locking device is used for circumferentially assembling the locking openings of the moving blades of the wheel-drum type rotor structure.

Description

Technical Field

[0001] The present invention relates to the field of steam turbine equipment in the energy and power industry, and in particular to a circumferentially installed steam turbine blade locking structure and an installation method thereof. Background Art

[0002] The steam turbine includes a rotor and a stator. The rotor is usually a disk-type or drum-type structure. The rotor is equipped with moving blades. For a disk-type rotor, the locking moving blades can be fixed to the rotor by axial pinning. For a drum-type rotor, since there is no disk, the locking moving blades cannot be fixed by axial pinning, so the moving blades adopt a circumferential assembly structure. Each stage of circumferentially assembled moving blades has one or two locking moving blades to limit other moving blades on the rotor from falling off the rotor. The present invention proposes a blade locking structure suitable for circumferentially mounted drum rotors, and in particular provides a solution for special small-sized compact steam turbines with limited axial dimensions for ships. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the existing drum rotor has no wheel disk and therefore cannot fix the locking moving blades by axial pinning, and the circumferentially mounted blades of the drum rotor cannot be suitable for small compact steam turbines with limited axial dimensions, and further to provide a circumferentially mounted turbine blade locking structure and an installation method thereof.

[0004] The technical solution of the present invention is:

[0005] A circumferentially mounted steam turbine blade locking structure comprises a blade locking member 2, a thrust wedge 3, a blade 1 and a rotor 4. The number of blades 1 is multiple, and the multiple blades 1 are evenly arranged in the rotor wheel groove of the rotor 4 along the circumferential direction. A blade installation window is processed on the rotor wheel groove. The blade locking member 2 is a split structure. The blade locking member 2 comprises a left blade locking block and a right blade locking block. The left blade locking block and the right blade locking block are arranged in the blade installation window. The thrust wedge 3 is vertically arranged between the left blade locking block and the right blade locking block. The left blade locking block and the right blade locking block are detachably connected to the rotor 4 through the thrust wedge 3.

[0006] Furthermore, the cross-section of the blade mounting window is in a dovetail form.

[0007] Furthermore, the left blade locking block and the right blade locking block are both in close axial contact with the dovetail inclined surface of the blade installation window.

[0008] Furthermore, the left blade locking block and the right blade locking block are in close contact with the blade root profile of the blade 1 in the circumferential direction.

[0009] Furthermore, the thrust wedge 3 is a rectangular thrust wedge.

[0010] Furthermore, thrust wedge mounting grooves matching the thrust wedge 3 are provided at the lower parts of the inner side surfaces of the left blade locking block and the right blade locking block.

[0011] Furthermore, a gap a is provided at the upper portion of the left blade locking block and the right blade locking block, and the width of the gap a is smaller than the width of the thrust wedge 3 .

[0012] Furthermore, the outer side surface of the left blade locking block and the upper part of the blade 1 are both provided with axial steam seal teeth.

[0013] Furthermore, a toothed groove matching the toothed root of the blade 1 is provided inside the rotor wheel groove, and the toothed root of the blade 1 is fixedly connected to the rotor 4 via the toothed groove.

[0014] A method for installing a turbine blade locking structure based on circumferential installation, the method is implemented by the following steps:

[0015] Step 1: Installation of blade 1:

[0016] First, multiple blades 1 are evenly installed in the rotor wheel groove of the rotor 2 in sequence along the circumferential direction and tightened, and the toothed blade root of each blade 1 is fixedly connected to the rotor 4 through the toothed groove inside the rotor wheel groove;

[0017] Step 2: Inspection of blade lock 2:

[0018] Before installing the blade lock piece 2, trim the blade lock piece 2, use paint to check the fit between the blade lock piece 2 and the first contact surface L of the dovetail slope at the blade installation window of the rotor 4, and check the parallelism of the second contact surface N of the blade lock piece 2 and the thrust wedge 3;

[0019] Step 3: Circumferential positioning of the blade locking member 2:

[0020] Install the left blade locking block and the right blade locking block in the blade installation window, and vertically insert the thrust wedge 3 between the left blade locking block and the right blade locking block, use a striking tool to drive the thrust wedge 3 into the locking, and fasten it to the bottom of the groove of the blade installation window. At this time, the left blade locking block and the right blade locking block are in close contact with the blade root profile of the blade 1 in the circumferential direction, and the left blade locking block and the right blade locking block are in close contact with the dovetail inclined surface of the blade installation window in the axial direction;

[0021] Step 4: Axial positioning of the blade locking member 2:

[0022] Finally, the upper parts of the left blade locking block and the right blade locking block are bent to the top of the thrust wedge 3, and a gap a is formed between the left blade locking block and the upper parts of the right blade locking block.

[0023] Compared with the prior art, the present invention has the following effects:

[0024] The circumferentially mounted turbine blade locking structure described in the present invention has a simple blade locking structure, high reliability, and is easy to process as well as assemble and replace blades. It is suitable for the locking of circumferentially assembled moving blades in a drum rotor structure, and is particularly suitable for special small compact drum rotor structures for ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a circumferentially mounted turbine blade locking structure according to the present invention;

[0026] Figure 2 yes Figure 1 The cross-sectional view at AA;

[0027] Figure 3 It is a structural schematic diagram of a rotor wheel groove in a circumferentially mounted turbine blade locking structure described in the present invention.

[0028] In the figure: 1. blade; 2. blade locking piece; 3. thrust wedge; 4. rotor. DETAILED DESCRIPTION

[0029] Specific implementation method 1: Combination Figures 1 to 3 The present embodiment is described. The present embodiment is a circumferentially mounted turbine blade locking structure, which includes a blade locking member 2, a thrust wedge 3, a blade 1 and a rotor 4. The number of blades 1 is multiple, and the multiple blades 1 are evenly arranged in the rotor wheel groove of the rotor 4 along the circumferential direction. A blade installation window is processed on the rotor wheel groove. The blade locking member 2 is a split structure. The blade locking member 2 includes a left blade locking block and a right blade locking block. The left blade locking block and the right blade locking block are arranged in the blade installation window. The thrust wedge 3 is vertically arranged between the left blade locking block and the right blade locking block. The left blade locking block and the right blade locking block are detachably connected to the rotor 4 through the thrust wedge 3.

[0030] Specific implementation method 2: Combination Figures 1 to 3 To explain this embodiment, the cross section of the blade installation window of this embodiment is in a dovetail shape. Other components and connection relationships are the same as those of the first embodiment.

[0031] Specific implementation method three: Combination Figures 1 to 3 To illustrate this embodiment, the left blade locking block and the right blade locking block of this embodiment are both in close axial contact with the dovetail inclined surface of the blade installation window. Other components and connection relationships are the same as those of the first or second embodiment.

[0032] Specific implementation method four: Combination Figures 1 to 3To explain this embodiment, the left blade locking block and the right blade locking block of this embodiment are in close contact with the blade root profile of the blade 1 in the circumferential direction. Other components and connection relationships are the same as those of the first, second or third specific embodiments.

[0033] Specific implementation method five: Combination Figures 1 to 3 To explain this embodiment, the thrust wedge 3 of this embodiment is a rectangular thrust wedge. Other components and connection relationships are the same as those of the first, second, third or fourth embodiments.

[0034] Specific implementation method six: Combination Figures 1 to 3 To explain this embodiment, the lower inner side surfaces of the left blade locking block and the right blade locking block of this embodiment are provided with thrust wedge mounting grooves matching the thrust wedge 3. Other components and connection relationships are the same as those of the first, second, third, fourth or fifth embodiments.

[0035] Specific implementation method seven: Combination Figures 1 to 3 To explain this embodiment, a gap a is provided on the upper part of the left blade locking block and the right blade locking block of this embodiment, and the width of the gap a is smaller than the width of the thrust wedge 3. Other components and connection relationships are the same as those of the specific embodiments 1, 2, 3, 4, 5 or 6.

[0036] Specific implementation method eight: Combination Figures 1 to 3 To explain this embodiment, the outer side surface of the left blade lock block and the upper part of the blade 1 are both provided with axial steam seal teeth. Other components and connection relationships are the same as those of the specific embodiments 1, 2, 3, 4, 5, 6 or 7.

[0037] Specific implementation method nine: Combination Figures 1 to 3 This embodiment is described. In this embodiment, a toothed groove matching the toothed root of the blade 1 is provided inside the rotor wheel groove. The toothed root of the blade 1 is fixedly connected to the rotor 4 through the toothed groove. Other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh or eighth embodiments.

[0038] Specific implementation method ten: Combination Figures 1 to 3 The present embodiment is described. The present embodiment is a method for installing a turbine blade lock structure based on a circumferential installation. The method is implemented by the following steps:

[0039] Step 1: Installation of blade 1:

[0040] First, multiple blades 1 are evenly installed in the rotor wheel groove of the rotor 2 in sequence along the circumferential direction and tightened, and the toothed blade root of each blade 1 is fixedly connected to the rotor 4 through the toothed groove inside the rotor wheel groove;

[0041] Step 2: Inspection of blade lock 2:

[0042] Before installing the blade lock piece 2, trim the blade lock piece 2, use paint to check the matching of the first contact surface L of the blade lock piece 2 and the dovetail slope at the blade installation window of the rotor 4, and check the parallelism of the second contact surface N of the blade lock piece 2 and the thrust wedge 3. The matching contact area between the blade lock piece 2 and the wheel groove contact surface should not be less than 75%, and the contact surface of the blade lock piece 2 and the thrust wedge 3 should be parallel or separated upward to meet the design requirements, and downward separation is not allowed (in other words, the red lead brushing contact surface of the L surface should not be less than 75%, when tightly matched along the L surface, the parallelism or upward separation of the N surface meets the design requirements, and the N surface is not allowed to separate downward);

[0043] Step 3: Circumferential positioning of the blade locking member 2:

[0044] The left blade locking block and the right blade locking block are installed in the blade installation window, and the thrust wedge 3 is vertically inserted between the left blade locking block and the right blade locking block, and the thrust wedge 3 is driven into the lock by a striking tool, and is fastened to the bottom of the groove of the blade installation window. At this time, the left blade locking block and the right blade locking block are in close contact (fitting) with the blade root profile of the blade 1 in the circumferential direction, and the left blade locking block and the right blade locking block are in close contact with the dovetail inclined surface of the blade installation window in the axial direction. The interference of the left blade locking block and the right blade locking block before being driven in meets the design requirements, and the axial interference of the thrust wedge 3 part size is aligned according to the measured size to meet the design requirements;

[0045] Step 4: Axial positioning of the blade locking member 2:

[0046] Finally, the upper parts of the left blade locking block and the right blade locking block are bent to the top of the thrust wedge 3, and a gap a is formed between the left blade locking block and the upper parts of the right blade locking block, and the gap a meets the design requirements. The other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth embodiment.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circumferentially mounted steam turbine blade locking structure, characterized in that: The invention comprises a blade locking member (2), a thrust wedge (3), a blade (1) and a rotor (4). The number of blades (1) is multiple, and the multiple blades (1) are evenly arranged in the rotor wheel groove of the rotor (4) along the circumferential direction. The rotor wheel groove is processed with a blade installation window. The blade locking member (2) is a split structure. The blade locking member (2) comprises a left blade locking block and a right blade locking block. The left blade locking block and the right blade locking block are arranged in the blade installation window. The thrust wedge (3) is vertically arranged between the left blade locking block and the right blade locking block. The left blade locking block and the right blade locking block are detachably connected to the rotor (4) through the thrust wedge (3).

2. A circumferentially mounted steam turbine blade locking structure according to claim 1, characterized in that: The cross section of the blade installation window is in a dovetail shape.

3. The locking structure of a circumferentially mounted steam turbine blade according to claim 2, characterized in that: The left blade locking block and the right blade locking block are both in close axial contact with the dovetail inclined surface of the blade installation window.

4. A circumferentially mounted steam turbine blade locking structure according to claim 1 or 3, characterized in that: The left blade locking block and the right blade locking block are in close contact with the blade root profile of the blade (1) in the circumferential direction.

5. The locking structure of a circumferentially mounted steam turbine blade according to claim 4, characterized in that: The thrust wedge (3) is a rectangular thrust wedge.

6. A circumferentially mounted steam turbine blade locking structure according to claim 5, characterized in that: The lower parts of the inner side surfaces of the left blade locking block and the right blade locking block are provided with thrust wedge mounting grooves matching the thrust wedge (3).

7. The locking structure of a circumferentially mounted steam turbine blade according to claim 6, characterized in that: A gap (a) is provided on the upper part of the left blade locking block and the right blade locking block, and the width of the gap (a) is smaller than the width of the thrust wedge (3).

8. The locking structure of a circumferentially mounted steam turbine blade according to claim 7, characterized in that: The outer side surface of the left blade locking block and the upper part of the blade (1) are both provided with axial steam seal teeth.

9. A circumferentially mounted steam turbine blade locking structure according to claim 8, characterized in that: A toothed groove matching the toothed blade root of the blade (1) is provided inside the rotor wheel groove, and the toothed blade root of the blade (1) is fixedly connected to the rotor (4) via the toothed groove.

10. A method for installing the circumferentially installed turbine blade locking structure according to claim 9, characterized in that: The method is implemented by the following steps: Step 1: Installation of blades (1): First, multiple blades (1) are evenly installed in the rotor wheel groove of the rotor 2 in sequence along the circumferential direction and tightened, and the toothed blade root of each blade (1) is fixedly connected to the rotor (4) through the toothed groove inside the rotor wheel groove; Step 2: Inspection of the blade lock (2): Before installing the blade locking member (2), the blade locking member (2) is trimmed, and the matching of the blade locking member (2) with the first contact surface (L) of the dovetail inclined surface at the blade installation window of the rotor (4) is checked with paint, and the parallelism of the blade locking member (2) with the second contact surface (N) of the thrust wedge (3) is checked; Step 3: Circumferential positioning of the blade locking member (2): The left blade locking block and the right blade locking block are installed in the blade installation window, and the thrust wedge (3) is vertically inserted between the left blade locking block and the right blade locking block, and the thrust wedge (3) is driven into the locking groove by a striking tool, and is fastened to the bottom of the groove of the blade installation window. At this time, the left blade locking block and the right blade locking block are in close contact with the blade root profile of the blade (1) in the circumferential direction, and the left blade locking block and the right blade locking block are in close contact with the dovetail inclined surface of the blade installation window in the axial direction; Step 4: Axial positioning of the blade locking member (2): Finally, the upper parts of the left blade locking block and the right blade locking block are bent to the top of the thrust wedge (3), and a gap (a) is formed between the upper parts of the left blade locking block and the right blade locking block.

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