A blade structure suitable for the secondary last stage moving blades of a peak-shaving half-speed nuclear power steam turbine

Abstract

The present invention discloses a blade structure suitable for a secondary-last-stage moving blade of a peak-shaving half-speed nuclear power steam turbine. The blade structure comprises a variable-section twisted profile formed by regularly superimposing a plurality of characteristic cross sections. Characteristic parameters of the characteristic cross sections include: an installation angle c1, a chord length b1, a maximum thickness w1, an axial width Xa, and a cross-sectional area A. The blade height H is 967 mm, the top meridian inclination angle d1° is 25°, and the relative value of the blade height H monotonically increases from 0.0 to 1.03. The absolute value of the installation angle c1 monotonically decreases from 67.5° to 23.3°. The characteristic parameters of each characteristic section are based on the root section. The relative value of the chord length b1 decreases from 1.0 to 0.99 from the root section to the adjacent X-X section, and the relative value of the chord length b1 monotonically increases from 0.99 to 1.07 from the X-X section to the top section. The relative value of the maximum thickness w1 monotonically decreases from 1.0 to 0.24 from the root section to the top section. The relative value of the axial width Xa monotonically decreases from 1.0 to 0.47 from the root section to the top section. The relative value of the cross-sectional area A monotonically decreases from 1 to 0.23 from the root section to the top section.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power steam turbines, and in particular to a blade body structure suitable for secondary and final stage moving blades of a peak-shaving half-speed nuclear power steam turbine. Background Art

[0002] To adjust its energy structure, my country is actively promoting nuclear power development to meet the growing energy demand driven by economic and social development while controlling carbon emissions. With the vigorous development of the nuclear power industry, the capacity of nuclear power units has gradually increased. Currently, the mainstream nuclear power power levels are concentrated in the 1000MW to 1700MW range. Therefore, improving the power generation efficiency and variable operating characteristics of units within this power range can significantly accelerate the development of my country's nuclear power and enhance the international competitiveness of my country's power generation equipment.

[0003] As the proportion of nuclear power in the power grid grows, the power system's demand for nuclear power units to participate in peak-shaving operations is increasing. Whether nuclear power can participate in peak-shaving operations, how to use them, and the impact on the grid's peak-shaving balance have become issues of great concern. As a key component of nuclear power, the efficiency of the steam turbine directly affects the overall economic performance of the unit. Its adaptability to power fluctuations determines the peak-shaving capability of the nuclear power plant. As the unit power level increases, the steam turbine capacity increases, and its initial parameters increase. The exhaust area of ​​the low-pressure cylinder increases, the length of the last and next-last stage blades increases, and the blade operating Mach number increases, which in turn increases the requirements for blade aerodynamic performance and strength. Therefore, it is urgent to intensify the development of long nuclear power blades suitable for peak-shaving. Summary of the Invention

[0004] The object of the present invention is to provide a blade structure with excellent aerodynamic characteristics and applicable to 1000MW to 1700MW nuclear power units in order to solve the above problems.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] A blade structure suitable for a secondary-last-stage moving blade of a peak-shaving half-speed nuclear power steam turbine. The blade structure comprises a variable-section twisted profile formed by regularly superimposing a plurality of characteristic cross sections. The characteristic parameters of the moving blade include: blade height H; the contour line of each characteristic cross section is a closed curve formed by an inner arc curve and a back arc curve; the characteristic parameters of the characteristic cross section include: installation angle c1, chord length b1, maximum thickness w1, axial width Xa, and cross-sectional area A; the superposition pattern of each characteristic cross section is a continuous and smooth transition from the root end to the tip end along the blade height direction; the blade height H is 967 mm, the top meridian inclination angle d1° is 25°, and the blade height H is 967 mm. The relative value monotonically increases from 0.0 to 1.03; the absolute value of the installation angle c1 monotonically decreases from 67.5° to 23.3°; the characteristic parameters of each characteristic section are based on the root section, the relative value of the chord length b1 decreases from 1.0 to 0.99 from the root section to the adjacent XX section, and the relative value of the chord length b1 monotonically increases from 0.99 to 1.07 from the XX section to the top section; the relative value of the maximum thickness w1 monotonically decreases from 1.0 to 0.24 from the root section to the top section; the relative value of the axial width Xa monotonically decreases from 1.0 to 0.47 from the root section to the top section; the relative value of the cross-sectional area A monotonically decreases from 1 to 0.23 from the root section to the top section.

[0007] The blade structure is formed by nine characteristic cross sections with different contour shapes, which transition continuously and smoothly from the root end to the tip end along the height direction of the blade.

[0008] The characteristic cross-section includes three key cross-sections, including the BB cross-section located at 0.0% of the blade height H, the MM cross-section located at 53.0% of the blade height H, and the TT cross-section located at 103% of the blade height H; the theoretical contour line of each key cross-section is described by the coordinates (X, Y) of several discrete points, and the discrete points are smoothly connected to obtain the theoretical contour line of the corresponding key cross-section.

[0009] The theoretical contour lines of each of the key sections are described by the coordinates (X, Y) of 28 discrete points.

[0010] The theoretical contour line of the BB section is described by the coordinates (X, Y) of the following discrete points: (-116.055, -110.786), (-117.83, -112.058), (-119.927, -111.452), (-120.75, -109.431), (-120.59, -108.698), (-107.556, -75.9117 ), (-92.5527,-43.9856), (-74.5255,-13.6774), (-52.4094,13.76274), (-25.3309,36.25969), (6.757282,50.57765), (41.74734,52.757), (74.6563,40.73128), (100.2 513,16.78605),(113.8459,-15.4597),(113.5563,-15.9611),(113.1652,-16.3879),(112.691,-16.7201),(112.5182,-16.8069),(86.69513,-10.0211),(60.16195,- 7.14585), (33.529,-8.86873), (7.457915,-14.6149), (-17.5962,-23.8462), (-41.3123,-36.1186), (-63.417,-51.1017), (-83.603,-68.5829), (-101.418,-88.4687).

[0011] The theoretical contour line of the MM section is described by the coordinates (X, Y) of the following discrete points: (-85.2451, -146.838), (-86.6261, -147.923), (-88.331, -147.501), (-89.0465, -145.897), (-88.9348, -145.303), (-78.0016, -116.515 ), (-66.8707,-87.8034), (-55.3224,-59.2571), (-42.9823,-31.0455), (-29.1712,-3.52939), (-12.6704,22.44242), (8.420228,44.76624), (35.55985,58.82779), (65.7 9783,57.47211),(82.4394,34.19384),(82.24031,33.78486),(81.98372,33.40929),(81.67511,33.07515),(81.5618,32.97424),(55.80604,32.90011),(31.74208,22. 91442), (10.64069, 7.516068), (-7.86711, -10.9434), (-24.1155, -31.4288), (-38.4256, -53.3175), (-51.2059, -76.1374), (-62.9538, -99.5081), (-74.1641, -123.142).

[0012] The theoretical contour line of the TT section is described by the coordinates (X, Y) of the following discrete points: (-53.4816, -158.395), (-54.4419, -159.327), (-55.7648, -159.122), (-56.3978, -157.943), (-56.341, -157.486), (-48.3708, -130.096 ), (-40.3414,-102.724), (-32.2676,-75.3645), (-24.1231,-48.0261), (-15.8197,-20.7357), (-7.15734,6.442573), (2.287198,33.3573), (13.46029,59.59182), (28.7 9489,83.5425),(53.09775,92.28627),(53.36251,91.81842),(53.53212,91.30831),(53.60021,90.77507),(53.5998,90.59563),(36.60023,69.45985),(23.12219,45. 77262), (11.76406, 20.98089), (1.430747, -4.25794), (-8.31454, -29.7303), (-17.6889, -55.3417), (-26.8184, -81.0415), (-35.7868, -106.798), (-44.6567, -132.589).

[0013] The contour line of each characteristic section may have a tolerance zone, and the range of the tolerance zone is: the contour shape range formed by the enveloping circle with a radius of 0.3mm to 0.8mm and a discrete point of the theoretical contour line corresponding to the characteristic section as the center of the circle.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The blade body of the next-to-last-stage moving blade of the present invention has multiple characteristic cross-sections. By optimizing the parameters of the contour lines of each characteristic cross-section, the blade body of the next-to-last-stage moving blade disclosed in the present invention has excellent aerodynamic performance. At the same time, the area variation along the height direction of the blade body is reasonable, and each characteristic cross-section of the blade body is high-order and smooth, with excellent subsonic and transonic flow characteristics. The stacking of each cross-section along the height of the blade body is continuous and smooth, and the area distribution is reasonable, so that the blade body of the last-stage moving blade disclosed in the present invention has the advantages of large strength margin and high reliability.

[0016] 2. The blade structure disclosed in the present invention can be applied to the four-exhaust low-pressure cylinder of the 1500r / min speed and 1000MW power level unit, and can also be extended to the six-exhaust low-pressure cylinder of the 1700MW power level unit. It matches the final stage of the existing large-capacity half-speed nuclear power unit with the sub-final stage moving blades with better performance, improves the efficiency of the low-pressure cylinder, improves the variable operating condition performance, meets the market economy and the peak regulation requirements of the power grid, and increases the market competitiveness of my country's power generation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the blade body of the present invention;

[0018] Figure 2 yes Figure 1 Schematic top view of

[0019] Figure 3 yes Figure 1 、 Figure 2 Schematic diagram of the characteristic cross section of the mid-blade structure;

[0020] Figure 4 It is a schematic diagram of the superposition of all characteristic sections;

[0021] The attached figure is marked with: blade height-H, installation angle-c1, chord length-b1, maximum thickness-w1, axial width-Xa, cross-sectional area-A. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. In addition, the terms "first," "second," etc. are used only to distinguish the descriptions and are not to be understood as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that “multiple” means two or more; the terms “upper”, “lower”, “left”, “right”, “inside”, “outside”, “front end”, “rear end”, “head”, “tail”, etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] like Figure 1 — Figure 4 The following figure shows a blade structure suitable for the secondary-last stage rotor blades of a peak-shaving half-speed nuclear steam turbine. The blade's characteristic parameters are designed as follows: Based on the required engineering boundary conditions, this blade profile is suitable for a 1500 rpm speed and can be used in nuclear power units rated 1000MW to 1700MW. The blade height is 967mm, the top meridional inclination angle d1° is 25°, and the optimal Mach number range is 0.8 to 1.1. The geometric inlet angle ranges from 40° to 130°.

[0027] Specifically, the blade design contour line of the moving blade body is obtained using 3D modeling software to obtain 9 characteristic cross-sections. The area variation law of each cross-section is modified according to the strength design requirements to obtain a cross-sectional area distribution that meets the strength requirements. The blade stage is then aerodynamically analyzed using full 3D computational fluid dynamics simulation software. Based on the flow characteristics of the stage, the local blade profile contour line is adjusted to obtain a characteristic cross-section that conforms to the root subsonic and top transonic flow characteristics. The blade stage is then aerodynamically analyzed using full 3D computational fluid dynamics simulation software. The blade body structure uses high-order Blezier curves and third-order C-spline curves to optimize, smooth, and locally fine-tune each characteristic cross-section.

[0028] like Figure 1 、 Figure 2 As shown, the blade body is formed by stacking multiple characteristic sections in a regular pattern to form a variable-section twisted profile. The specific characteristic parameters of the blade body are as follows: the blade body height H, that is, the distance between the blade body root section and the blade body top section, the blade body height H is equal to 967mm.

[0029] The contour line of each characteristic section is a closed curve composed of an inner arc curve and a back arc curve, mainly including the chord length b1, the installation angle c1, the maximum thickness w1, the axial width Xa, and the cross-sectional area A. Among them, the installation angle c1 is the angle between the chord length and the circumferential direction (Y direction); the chord length b1 is the distance between the inlet and outlet edges of the blade section; the maximum thickness w1 is the tangential width of the blade section; the cross-sectional area A is the area of ​​the blade cross section; and the axial width Xa is the axial width of the blade section.

[0030] The stacking rule of each characteristic section is a continuous and smooth transition from the root to the top along the blade height direction, and the relative value of the blade height H monotonically increases from 0.0 to 1.03; the absolute value of the installation angle c1 monotonically decreases from 67.5° to 23.3°; the characteristic parameters of each characteristic section are based on the root section, the relative value of the chord length b1 decreases from 1.0 to 0.99 from the root section to the similar XX section, and the relative value of the chord length b1 monotonically increases from 0.99 to 1.07 from the XX section to the top section; the relative value of the maximum thickness w1 monotonically decreases from 1.0 to 0.24 from the root section to the top section; the relative value of the axial width Xa monotonically decreases from 1.0 to 0.47 from the root section to the top section; the relative value of the cross-sectional area A monotonically decreases from 1 to 0.23 from the root section to the top section.

[0031] The critical sections are determined as follows: Figure 4 As shown in Table 1, the blade structure consists of 9 characteristic sections with different contour shapes that transition continuously and smoothly from the root end to the top end along the blade height H direction. The order of arrangement of each characteristic section from the root to the top is 1 to 9. As shown in Table 1, the characteristic section includes three key sections (such as Figure 1 ), the key sections include the BB section located at 0.0% of the blade height H, the MM section located at 53.0% of the blade height H, and the TT section located at 103% of the blade height H; the theoretical contour line of each key section is described by the coordinates (X, Y) of several discrete points, and the discrete points are smoothly connected to obtain the theoretical contour line of the corresponding key section.

[0032] Table 1 Relative heights of three key sections at the blade height H

[0033] Section name Relative leaf height BB 0.0％ MM 53.0％ TT 103

[0034] As shown in Table 2, the theoretical contour lines of the BB, MM, and TT sections are described by the coordinates (X, Y) of the following discrete points:

[0035] Table 2 Coordinate data of discrete points of three key sections

[0036]

[0037]

[0038] The actual dimensions of the contour lines of each characteristic cross-section are subject to a tolerance zone. The tolerance zone is defined as the contour shape range formed by an enveloping circle with a radius of 0.3 mm to 0.8 mm, centered at a discrete point on the theoretical contour line of the corresponding characteristic cross-section. The above is only the optimal solution; alternatively, the shape and dimensions may be determined by similar modeling, rotation, or translation based on the theoretical contour line.

[0039] The blade structure provided in this embodiment is designed as a basis for the secondary-last-stage moving blades of a peak-shaving half-speed nuclear power steam turbine. It not only has advanced aerodynamic characteristics but also meets strength requirements.

[0040] The above specific technical solutions are only used to illustrate the present invention, not to limit it. Although the present invention has been described in detail with reference to the above specific technical solutions, those skilled in the art should understand that the present invention can still modify the above specific technical solutions, or make equivalent replacements for some of the technical features therein, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A blade structure suitable for the secondary-last stage rotor blades of a peak-shaving half-speed nuclear power steam turbine, wherein the blade structure comprises a variable-section twisted profile formed by regularly stacking a plurality of characteristic cross sections. The characteristic parameters of the rotor blade include: Blade height H; The contour line of each characteristic section is a closed curve surrounded by an inner arc curve and a back arc curve. The characteristic parameters of the characteristic section include: installation angle c1, chord length b1, maximum thickness w1, axial width Xa, and cross-sectional area A. The superposition rule of each characteristic section is a continuous and smooth transition from the root end to the top end along the blade height direction. It is characterized in that: the blade height H is 967mm, the top meridian inclination angle d1° is 25°, the relative value of the blade height H increases monotonically from 0.0 to 1.03; the absolute value of the installation angle c1 decreases monotonically from 67.5° to 1.

03. The characteristic parameters of each characteristic section are based on the root section, the relative value of the chord length b1 decreases from 1.0 to 0.99 from the root section to the adjacent XX section, and the relative value of the chord length b1 monotonically increases from 0.99 to 1.07 from the XX section to the top section; the relative value of the maximum thickness w1 monotonically decreases from 1.0 to 0.24 from the root section to the top section; the relative value of the axial width Xa monotonically decreases from 1.0 to 0.47 from the root section to the top section; the relative value of the cross-sectional area A monotonically decreases from 1 to 0.23 from the root section to the top section.

2. The blade structure for the secondary-last stage moving blade of a peak-shaving half-speed nuclear power steam turbine according to claim 1 is characterized in that: The blade structure is formed by nine characteristic cross sections with different contour shapes, which transition continuously and smoothly from the root end to the tip end along the height direction of the blade.

3. The blade structure for the secondary-last stage moving blade of a peak-shaving half-speed nuclear power steam turbine according to claim 1 or 2, characterized in that: The characteristic cross-section includes three key cross-sections, including the BB cross-section located at 0.0% of the blade height H, the MM cross-section located at 53.0% of the blade height H, and the TT cross-section located at 103% of the blade height H; the theoretical contour line of each key cross-section is described by the coordinates (X, Y) of several discrete points, and the discrete points are smoothly connected to obtain the theoretical contour line of the corresponding key cross-section.

4. The blade structure suitable for the secondary-last stage moving blade of a peak-shaving half-speed nuclear power steam turbine according to claim 3 is characterized in that: The theoretical contour lines of each of the key sections are described by the coordinates (X, Y) of 28 discrete points.

5. The blade structure for the secondary-last stage moving blade of a peak-shaving half-speed nuclear power steam turbine according to claim 3 is characterized in that: The theoretical contour line of the BB section is described by the coordinates (X, Y) of the following discrete points: (-116.055, -110.786), (-117.83, -112.058), (-119.927, -111.452), (-120.75, -109.431), (-120.59, -108.698), (-107.556, -75.9117), (-92.5527, -43.9856), (-74.5255, -13.6774), (-52.4094, 13.76274), (-25.3309, 36.25969), (6.757282, 50.57765), (41.74734, 52.757), (74.6563, 40.73128),(100.2513, 16.78605),(113.8459, -15.4597),(113.5563, -15.9611),(113.1652, -16.3879),(112.691, -16.7201),(112.5182, -16.8069),(86.69513, -10.0211),(60.16195, -7.14585),(33.529, -8.86873),(7.457915, -14.6149),(-17.5962, -23.8462),(-41.3123, -36.1186),(-63.417, -51.1017), (-83.603, -68.5829), (-101.418, -88.4687).

6. The blade structure for the secondary-last stage moving blade of a peak-shaving half-speed nuclear power steam turbine according to claim 3 is characterized in that: The theoretical contour line of the MM section is described by the coordinates (X, Y) of the following discrete points: （-85.2451, -146.838），（-86.6261, -147.923），（-88.331, -147.501），（-89.0465,-145.897），（-88.9348, -145.303），（-78.0016, -116.515），（-66.8707, -87.8034），（-55.3224, -59.2571），（-42.9823, -31.0455），（-29.1712, -3.52939），（-12.6704,22.44242），（8.420228, 44.76624），（35.55985, 58.82779），（65.79783, 57.47211），（82.4394, 34.19384），（82.24031, 33.78486），（81.98372, 33.40929），（81.67511,33.07515），（81.5618, 32.97424），（55.80604, 32.90011），（31.74208, 22.91442），（10.64069, 7.516068），（-7.86711, -10.9434），（-24.1155, -31.4288），（-38.4256, -53.3175），（-51.2059, -76.1374），（-62.9538, -99.5081），（-74.1641, -123.142）。 7. The blade structure for the secondary-last stage moving blade of a peak-shaving half-speed nuclear power steam turbine according to claim 3 is characterized in that: The theoretical contour line of the TT section is described by the coordinates (X, Y) of the following discrete points: (-53.4816, -158.395), (-54.4419, -159.327), (-55.7648, -159.122), (-56.3978, -157.943), (-56.341, -157.486), (-48.3708, -130.096), (-40.3414, -102.724), (-32.2676, -75.3645), (-24.1231, -48.0261), (-15.8197, -20.7357), (-7.15734, 6.442573), (2.287198, 33.3573), (13.462929, 59.59182),(28.79489, 83.5425),(53.09775,92.28627),(53.36251, 91.81842),(53.53212, 91.30831),(53.60021, 90.77507),(53.5998, 90.59563),(36.60023, 69.45985),(23.12219, 45.77262),(11.76406,20.98089),(1.430747, -4.25794),(-8.31454, -29.7303),(-17.6889, -55.3417),(-26.8184, -81.0415), (-35.7868, -106.798), (-44.6567, -132.589).

8. The blade structure for the secondary-last stage moving blade of a peak-shaving half-speed nuclear power steam turbine according to claim 1 or 2, characterized in that: The contour line of each characteristic section may have a tolerance zone, and the range of the tolerance zone is: the contour shape range formed by the enveloping circle with a radius of 0.3mm to 0.8mm and a discrete point of the theoretical contour line corresponding to the characteristic section as the center of the circle.

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