CN110513151B

CN110513151B - Blade body structure of titanium alloy final-stage moving blade of large-scale steam turbine

Info

Publication number: CN110513151B
Application number: CN201910841315.1A
Authority: CN
Inventors: 周显丁; 周帅; 蒲守武; 魏艳; 苟小平; 王姗; 范志飞; 尹明艳; 钟主海; 陈阳; 邓国梁; 陈涛; 江南; 靳亚峰
Original assignee: DEC Dongfang Turbine Co Ltd
Current assignee: DEC Dongfang Turbine Co Ltd
Priority date: 2019-09-06
Filing date: 2019-09-06
Publication date: 2022-05-10
Anticipated expiration: 2039-09-06
Also published as: CN110513151A

Abstract

The invention discloses a blade body structure of a titanium alloy final-stage moving blade of a large-scale steam turbine, belonging to the technical field of steam turbines, wherein the blade body structure comprises a variable cross-section twisted molded line formed by regularly overlapping a plurality of characteristic cross sections; the contour line of each characteristic section is a closed curve formed by an inner arc curve and a back arc curve, the superposition rule of each characteristic section is that the characteristic sections are continuously and smoothly transited from the root end to the top end along the height direction of the blade body, the relative value of the height H of the blade body is monotonically increased from 0.0 to 1.0, and the absolute value of the installation angle c1 is monotonically decreased from 81.16 to 8.87; the characteristic parameters of each characteristic section are based on the top section, the relative value of the chord length b1 is monotonically decreased from 1.65 to 1.0 from the root section to the top section, the relative value of the maximum thickness w1 is monotonically decreased from 4.24 to 1.0 from the root section to the top section, the relative value of the axial width Xa is monotonically decreased from 11.33 to 1.0 from the root section to the top section, and the relative value of the sectional area A is monotonically decreased from 8.84 to 1.0 from the root section to the top section, so as to meet the strength design requirement.

Description

Blade body structure of titanium alloy final-stage moving blade of large-scale steam turbine

Technical Field

The invention belongs to the technical field of steam turbines, and particularly relates to a blade body structure of a titanium alloy final-stage moving blade of a large-scale steam turbine.

Background

Through development for many years, thermal power turbine products almost cover various turbines from thousands of kilowatts to millions of kilowatts, which meet market demands, form a perfect last stage blade development criterion, and have strong last stage blade development capacity. A relatively complete last-stage blade series is developed to meet the requirement of the steam exhaust area of each steam turbine product and realize the optimal performance matching of the unit.

With the continuous and high-speed increase of national economy, the national demand for electricity is also rapidly increased, and the generator set with medium capacity cannot meet the requirements of power demand and environmental protection and energy conservation. The development of high-parameter, high-capacity, high-efficiency and environment-friendly coal-fired power stations is a main problem facing and urgently to be solved in the power generation industry, and one of main factors limiting the large-capacity of a unit is the length of a final-stage blade. In the global scope, the number of steam turbine manufacturers mastering high initial parameters and high capacity coal-fired power station technology is small, and various types of steam turbines with power grades from 600MW to 1300MW can be designed by adopting different numbers of exhaust cylinders and modular design due to the restriction of last stage long blades of the steam turbines.

The optimal annular speed of the exhaust steam exists in each type of last-stage blades, and the exhaust steam loss is small and the efficiency is high near the optimal annular speed of the exhaust steam. The large capacity of the thermal generator set can improve the economy of the set and the high power generation density, thereby saving the investment of electric power construction and reducing the capital construction investment and the operation and maintenance cost of a power plant; in view of reducing the manufacturing cost of the steam turbine, it is necessary to adopt 1400 mm-grade ultra-long final-stage blades which are suitable for ultra-supercritical large-capacity 4F-1200 MW-1300 MW-grade steam turbines and have higher technical content and higher blade height.

Disclosure of Invention

In view of the above, in order to solve the above problems in the prior art, the present invention provides a blade body structure of a titanium alloy final stage moving blade of a large steam turbine, so as to achieve the purpose that the titanium alloy final stage moving blade can match with large steam turbine models, such as 1000MW class and 1300MW class four-row steam turbine models.

The technical scheme adopted by the invention is as follows: the utility model provides a blade body structure of large-scale steam turbine titanium alloy last stage moving blade, this blade body structure include that a plurality of characteristic cross section superposes according to the law and forms the variable cross section distortion molded lines, the characteristic parameter of blade body structure includes: the height H of the blade body; the contour line of each characteristic section is a closed curve formed by an inner arc curve and a back arc curve, and the characteristic parameters of the characteristic sections comprise: the blade is characterized by comprising a mounting angle c1, a chord length b1, a maximum thickness w1, an axial width Xa and a sectional area A, wherein the superposition rule of all characteristic sections is that the characteristic sections are continuously and smoothly transited from a root end to a top end along the height direction of the blade body, the relative value of the height H of the blade body is monotonically increased from 0.0 to 1.05, and the absolute value of a mounting angle c1 is monotonically decreased from 81.0 to 81.5 to 8.5 to 9.0; the characteristic parameters of each characteristic section are based on the top section, the relative value of the chord length b1 monotonically decreases from 1.6-1.7 to 1.0 from the root section to the top section, the relative value of the maximum thickness w1 monotonically decreases from 4.0-4.5 to 1.0 from the root section to the top section, the relative value of the axial width Xa monotonically decreases from 11.0-11.5 to 1.0 from the root section to the top section, and the relative value of the sectional area A monotonically decreases from 8.5-9.0 to 1.0 from the root section to the top section.

Furthermore, the blade body structure is formed by continuous and smooth transition of 42 characteristic cross sections with different contour shapes from the root end to the top end along the height direction of the blade body.

Further, a B-B section at a blade height H of 4.15%, an M-M section at a blade height H of 50.37% and a Y-Y section at a blade height H of 98.53% are respectively taken as key sections, theoretical contour lines of the key sections are respectively described by coordinates (X, Y) of a plurality of discrete points, and the discrete points are smoothly connected to obtain the theoretical contour lines of the corresponding key sections.

Further, the theoretical contour lines of the respective critical sections are described by coordinates (X, Y) of 28 discrete points, respectively.

Further, the theoretical contour of the B-B cross-section is described by the coordinates (X, Y) of the following discrete points:

(-221.02，-121.66)，(-218.08，-121.29)，(-223.61，-119.26)，(-194.97，-89.89)，(-172.06，-58.05)，(-136.95，-28.30)，(-108.53，-2.35)，(-71.79，18.64)，(-27.33，33.88)，(9.01，42.85)，(56.25，45.23)，(93.33，40.95)，(139.24，30.19)，(173.03，13.30)，(221.32，-25.34)，(225.25，-28.43)，(217.53，-30.25)，(186.55，-16.43)，(145.23，-2.18)，(112.33，7.10)，(68.55，11.47)，(29.55，10.49)，(-3.96，4.21)，(-46.39，-6.82)，(-77.37，-21.94)，(-116.73，-40.47)，(-144.48，-61.71)，(-180.43，-85.50)。

further, the theoretical contour of the M-M cross-section is described by the coordinates (X, Y) of the following discrete points:

(-75.60，-157.84)，(-71.80，-158.07)，(-77.52，-157.09)，(-67.32，-142.73)，(-63.07，-118.99)，(-48.78，-95.26)，(-44.39，-71.58)，(-34.87，-47.95)，(-19.96，-24.48)，(-14.13，-1.42)，(3.39，20.76)，(13.55，41.21)，(37.10，58.60)，(53.97，71.57)，(81.11，80.41)，(87.20，79.74)，(82.53，78.50)，(73.58，62.77)，(50.57，46.22)，(38.74，28.49)，(18.16，9.64)，(3.64，-10.03)，(-5.01，-30.32)，(-22.86，-51.13)，(-29.86，-72.44)，(-45.98，-94.22)，(-51.32，-116.38)，(-66.37，-138.68)。

further, the theoretical contour of the Y-Y section is described by the coordinates (X, Y) of the following discrete points:

(-19.86，-161.88)，(-16.45，-162.59)，(-22.70，-161.38)(-15.89，-146.47)，(-16.61，-122.03)，(-7.16，-97.62)，(-7.75，-73.21)，(-3.45，-48.78)，(5.67，-24.31)，(4.46，0.21)，(12.75，24.80)(10.36，49.47)，(17.15，74.21)，(13.58，98.98)，(18.43，126.39)，(24.90，127.11)，(21.31，126.29)，(27.45，104.80)，(20.47，80.03)，(22.74，55.33)，(14.55，30.68)，(10.95，6.09)，(12.02，-18.44)，(2.87，-42.94)，(3.60，-67.43)，(-5.66，-91.91)，(-4.92，-116.39)，(-14.48，-140.82)。

further, the contour line of each of the characteristic cross sections has a tolerance band, and the range of the tolerance band is as follows: the discrete point of the theoretical contour line of the corresponding characteristic section is taken as the center of a circle, and the radius is 0.38 mm-0.76 mm and is taken as the envelope circle to form the contour shape within the range.

The invention has the beneficial effects that:

1. by adopting the blade body structure of the titanium alloy final-stage moving blade of the large-scale steam turbine, disclosed by the invention, through optimizing contour line parameters of characteristic sections of the blade body, the pneumatic performance of each section of the blade body is excellent, the area change along the height direction of the blade body is reasonable, the characteristic sections of the blade body are high-order and smooth, the flow characteristics of subsonic, transonic and supersonic speed are excellent, and the pneumatic performance is excellent.

2. By adopting the blade body structure of the titanium alloy final-stage moving blade of the large-scale steam turbine, the titanium alloy final-stage moving blade of the steam turbine with the height of the gas outlet channel equal to 1450mm can be designed on the basis of the blade body structure, the maximum equivalent stress of the blade is lower than the yield limit of the blade material, and the strength characteristic of the blade meets the strength specification structure requirement of the material; the blade formed by the blade body structure can be suitable for an ultra-supercritical 3000r/min low-pressure four-steam-exhaust 950MW-1500 MW-grade unit, and also can be popularized and applied to a low-pressure single-steam-exhaust 220MW-400 MW-grade combined cycle steam turbine and a 50Hz ultra-supercritical, supercritical and subcritical low-pressure two-steam-exhaust 550MW-900 MW-grade unit, so that the requirement of a large-capacity unit on a final-stage long blade is met, the final-stage blade series is perfected, the positive influence on the improvement of the comprehensive strength and the brand effect of the national major equipment industry is generated, the market competitiveness of domestic power generation equipment is greatly improved, and obviously, the generated effect and the social and economic benefits are huge.

Drawings

FIG. 1 is a schematic structural diagram of a blade body structure of a titanium alloy final-stage moving blade of a large-scale steam turbine provided by the invention;

FIG. 2 is a schematic top view of FIG. 1;

FIG. 3 is a characteristic cross-sectional schematic view of the blade structure of FIGS. 1 and 2;

FIG. 4 is a schematic view of the superposition of cross-sections including all of the characteristic cross-sections of FIG. 3;

the figures are labeled as follows:

the height of the blade body is-H, the installation angle is-c 1, the chord length is-b 1, the maximum thickness is-w 1, the axial width is-Xa, and the sectional area is-A.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present invention, it should be noted that the indication of the orientation or the positional relationship is based on the orientation or the positional relationship shown in the drawings, or the orientation or the positional relationship which is usually placed when the product of the present invention is used, or the orientation or the positional relationship which is usually understood by those skilled in the art, or the orientation or the positional relationship which is usually placed when the product of the present invention is used, and is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the indicated device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, cannot be understood as limiting the present invention. Furthermore, the terms "first" and "second" are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be further noted that the terms "disposed" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood as specific cases to those of ordinary skill in the art; the drawings in the embodiments are used for clearly and completely describing the technical scheme in the embodiments of the invention, and obviously, the described embodiments are a part of the embodiments of the invention, but not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Example 1

In this embodiment, a blade body structure of a titanium alloy final-stage moving blade of a large-scale steam turbine is specifically provided, and characteristic parameters of the blade body structure are designed as follows: based on the boundary conditions required by engineering, the exhaust speed range of the set of blade type is determined to be 200-250 m/s, the range of the root diameter is 1800-2000 mm, and the maximum exhaust area is 15.3m²The effective blade height is equal to 1450mm, and the maximum using Mach number is less than 2.0.

And (3) completing through-flow matching of the low-voltage module by adopting a streamline curvature method, determining basic characteristic parameters of the blade body structure, wherein the range of a geometric air inlet angle is 46-176 degrees, and the range of an effective geometric angle is 36.4-6 degrees.

In this embodiment, the contour line of the blade body structural design adopts three-dimensional modeling software to obtain 42 characteristic cross sections, and the area change rule of each cross section is modified according to the strength design requirement, so as to obtain the blade profile area distribution meeting the strength requirement. And (3) carrying out pneumatic analysis on the blade stages by adopting full-ternary CFD analysis software, and locally adjusting the contour lines of the blade profiles according to the flow characteristics of the blade stages to obtain characteristic sections meeting requirements of root subsonic flow, middle transonic flow and top supersonic flow.

In this embodiment, the blade body structure optimization adopts a high-order Bezier curve and a third-order C-spline curve to perform profile line fairing and local modification on 42 characteristic cross sections, and adopts full ternary optimization software Design3D to perform pneumatic performance optimization on profiles of all cross sections of the movable blade, so as to obtain all characteristic cross sections with geometrically high-order fairing, and meanwhile, the pneumatic performance is excellent.

In the present embodiment, the blade body structure is characterized as follows:

as shown in fig. 1 and fig. 2, the blade body structure includes a variable cross-section twisted profile formed by regularly overlapping a plurality of characteristic cross sections, and the characteristic parameters of the blade body structure include: the height H of the blade body, namely the distance between the top section of the blade body and the root section of the blade body, is equal to 1450 mm; the contour line of each characteristic section is a closed curve formed by an inner arc curve and a back arc curve, and as shown in fig. 3, the characteristic parameters of each characteristic section include: the mounting angle c1, the chord length b1, the maximum thickness w1, the axial width Xa and the sectional area A, wherein the mounting angle c1 is the included angle between the chord length and the circumferential direction (Y direction); chord length b1, i.e. the distance between the inlet and outlet edges of the blade body section; maximum thickness w1, i.e. the tangential width of the blade body cross-section; the sectional area A is the area of the cross section of the blade body; axial width Xa, i.e. the axial width of the blade airfoil section.

The superposition rule of each characteristic section is that the superposition rule is continuously decreased from the root end to the top end along the height direction of the blade body and is in smooth transition, the relative value of the height H of the blade body is monotonically increased from 0.0 to 1.0, and the absolute value of the installation angle c1 is monotonically decreased from 81.16 to 8.87; the characteristic parameters of each characteristic section are based on the top section, the relative value of the chord length b1 is monotonically decreased from 1.65 to 1.0 from the root section to the top section, the relative value of the maximum thickness w1 is monotonically decreased from 4.24 to 1.0 from the root section to the top section, the relative value of the axial width Xa is monotonically decreased from 11.33 to 1.0 from the root section to the top section, and the relative value of the sectional area A is monotonically decreased from 8.84 to 1.0 from the root section to the top section.

Determining key cross sections in the following manner, wherein as shown in fig. 4, the blade body structure is formed by continuously and smoothly transiting 42 characteristic cross sections with different contour shapes from the root end to the top end along the height H direction of the blade body, and the arrangement sequence of the characteristic cross sections from the root to the top is 1-42; as shown in table 1, a B-B section (serial number 14), an M-M section (serial number 25) and a Y-Y section (serial number 40) at 4.15% of the blade height H, 50.37% of the blade height H and 98.53% of the blade height H were respectively used as key sections, and the theoretical contour lines of the key sections were respectively described by coordinates (X, Y) of a plurality of discrete points, and the discrete points were smoothly connected to obtain the theoretical contour lines of the corresponding key sections. Preferably, in this embodiment, the theoretical contour lines of the respective critical cross-sections are described by coordinates (X, Y) of 28 discrete points, respectively.

TABLE 1 relative height of three key sections at blade height H

Name of cross section	Relative leaf height
		B-B	4.15％
M-M	50.37％
		Y-Y	98.53％

As shown in Table 2, the theoretical contours of the B-B section, the M-M section, and the Y-Y section are described by the coordinates (X, Y) of the following discrete points, respectively:

TABLE 2 coordinate data of discrete points of three key sections

In this embodiment, the actual size of the contour line of each characteristic cross section has a tolerance band, and the range of the tolerance band is as follows: the discrete point of the theoretical contour line of the corresponding characteristic section is taken as the center of a circle, and the radius is 0.38mm, so that the contour shape range is formed. The above is only an optimum solution, and it is also possible to be within the range of the shape size obtained by similar modeling or rotation or translation with the theoretical contour line as a reference.

The final-stage moving blade of the titanium alloy of the steam turbine with the molded line air passage height equal to 1450mm is designed on the basis of the blade body structure provided by the embodiment, and not only has advanced aerodynamic characteristics, but also can meet the strength requirement.

The invention is not limited to the above alternative embodiments, and any other various forms of products can be obtained by anyone in the light of the present invention, but any changes in shape or structure thereof, which fall within the scope of the present invention as defined in the claims, fall within the scope of the present invention.

Claims

1. The utility model provides a blade body structure of large-scale steam turbine titanium alloy last stage moving blade, this blade body structure include that a plurality of characteristic cross section superposes according to the law and forms the variable cross section distortion molded lines, the characteristic parameter of blade body structure includes: the height H of the blade body; the contour line of each characteristic section is a closed curve formed by an inner arc curve and a back arc curve, and the characteristic parameters of the characteristic sections comprise: the mounting angle c1, the chord length b1, the maximum thickness w1, the axial width Xa and the sectional area A are characterized in that the superposition rule of all the characteristic sections is that the characteristic sections are continuously and smoothly transited from the root end to the top end along the height direction of the blade body, the height H of the blade body is equal to 1450mm, the relative value of the height H of the blade body is monotonically increased from 0.0 to 1.0, and the absolute value of the mounting angle c1 is monotonically decreased from 81.16 degrees to 8.87 degrees; the characteristic parameters of each characteristic section are based on the top section, the relative value of the chord length b1 is monotonically decreased from 1.65 to 1.0 from the root section to the top section, the relative value of the maximum thickness w1 is monotonically decreased from 4.24 to 1.0 from the root section to the top section, the relative value of the axial width Xa is monotonically decreased from 11.33 to 1.0 from the root section to the top section, and the relative value of the sectional area A is monotonically decreased from 8.84 to 1.0 from the root section to the top section.

2. The blade body structure of a titanium alloy last stage moving blade of a large steam turbine according to claim 1, wherein the blade body structure is formed by a continuous and smooth transition from a root end to a tip end of 42 characteristic cross sections with different contour shapes along a height direction of the blade body.

3. The blade body structure of a titanium alloy last stage moving blade for a large steam turbine according to claim 1, wherein the B-B section at a blade body height H of 4.15%, the M-M section at a blade body height H of 50.37%, and the Y-Y section at a blade body height H of 98.53% are respectively used as key sections, and the theoretical contour line of each key section is described by coordinates (X, Y) of a plurality of discrete points, and the discrete points are smoothly connected to obtain the theoretical contour line of the corresponding key section.

4. The airfoil structure for a titanium alloy last stage moving blade of a large steam turbine according to claim 1, wherein theoretical contour lines of each critical section are described by coordinates (X, Y) of 28 discrete points, respectively.

5. The blade body structure of a titanium alloy last stage moving blade of a large steam turbine according to claim 3, wherein the theoretical contour line of the B-B section is described by coordinates (X, Y) of discrete points as follows:

6. the blade body structure of a titanium alloy last stage moving blade of a large steam turbine according to claim 3, wherein the theoretical contour line of the M-M section is described by coordinates (X, Y) of discrete points as follows:

7. the blade body structure of a titanium alloy last stage moving blade of a large steam turbine according to claim 3, wherein the theoretical contour of the Y-Y section is described by the coordinates (X, Y) of the following discrete points:

8. the blade body structure of a titanium alloy last stage moving blade of a large steam turbine according to claim 1, wherein the contour line of each of the characteristic cross sections has a tolerance band, and the tolerance band is within a range of: the discrete point of the theoretical contour line of the corresponding characteristic section is taken as the center of a circle, and the radius is 0.38 mm-0.76 mm and is taken as the envelope circle to form the contour shape within the range.