CN109057872B

CN109057872B - Steam turbine blade

Info

Publication number: CN109057872B
Application number: CN201810861252.1A
Authority: CN
Inventors: 褚礼政; 褚世卿; 王亚慧
Original assignee: Changzhou Jintan Environmental Protection Equipment Co ltd
Current assignee: Changzhou Jintan Environmental Protection Equipment Co ltd
Priority date: 2018-08-01
Filing date: 2018-08-01
Publication date: 2021-01-05
Anticipated expiration: 2038-08-01
Also published as: CN109057872A

Abstract

The invention discloses a turbine blade, comprising: two half-shells that snap together to form a cavity; a flexible dividing member provided between the two half shells to divide a cavity into at least a cooling flow passage near a front side of the blade and to support the two half shells at the same time; wherein: the flexible partition is capable of changing with deformation of the half shells to accommodate shape changes of the blades. The flexible dividing piece adapts to the deformation of the half shells through deformation, so that excessive strain and stress concentration cannot be generated at the joint of the two half shells or the joint of the half shells and the flexible dividing piece, and cracking of the two half shells at the joint or cracking of the half shells and the supporting piece at the joint can be effectively prevented.

Description

Steam turbine blade

Technical Field

The invention relates to the technical field of power equipment, in particular to a turbine blade.

Background

As is known, blades on steam turbines are the main power generating components, and the temperature of the blades increases due to friction with the external environment (e.g., gas) during rotation of the blades with an impeller, and therefore, they are generally configured to have a cavity therein so as to introduce a cooling medium into the cavity to cool the blades.

Fig. 1 is a schematic view of an outline structure of a blade in the prior art, and fig. 2 is a sectional view of the blade. As shown in fig. 2 in conjunction with fig. 1, a blade 100 in the related art is formed by butt-joining two half shells 101 by welding or bonding, and has a cavity formed therein, and in order to form a plurality of cooling passages extending in a radial direction (a longitudinal direction of the blade), the blade is divided by a support member 102 to form the plurality of cooling passages. Effect of the support on the blade: on the one hand for forming the cooling channels and on the other hand for supporting the blade to maintain the blade shape.

In the prior art, the supporting member is a rigid member that is not affected by temperature, that is, the supporting length of the supporting member does not change when the temperature changes, and the supporting member and the blade are usually welded. However, such rigid parts cause the following disadvantages to the blade during operation:

the cooling of the blade by the cooling channel has the defect that the temperature of the inner surface of the blade is higher than that of the outer surface of the blade, that is, a temperature difference is formed between the outer surface and the inner surface, and the temperature difference of one side (referred to as a front side) of the blade in the moving direction is larger, the temperature difference can cause the two half shells forming the blade to generate larger strain on the front side, and the rigid member can not change due to the temperature change of the length of the rigid member, so that the rigid member can not adapt to the shape change (strain) of the half shells, and the two half shells can crack at the joint or the half shells and the supporting member can crack at the joint.

The turbine blade bears a large bending moment in the working process under the action of high-temperature and high-pressure steam, and the moving blade in high-speed operation also bears a high centrifugal force; the blade in the wet swallow steam area is also subjected to electrochemical corrosion and water drop erosion, and the conventional turbine blade has poor corrosion resistance, poor erosion resistance, poor vibration attenuation resistance and poor wear resistance.

Disclosure of Invention

In view of the above technical problems in the prior art, embodiments of the present invention provide a steam turbine blade.

In order to solve the technical problem, the embodiment of the invention adopts the following technical scheme:

a steam turbine blade comprising:

two half-shells that snap together to form a cavity;

a flexible dividing member provided between the two half shells to divide a cavity into at least a cooling flow passage near a front side of the blade and to support the two half shells at the same time; wherein:

the flexible partition is capable of changing with deformation of the half shells to accommodate shape changes of the blades.

Preferably, the flexible partition comprises:

a first pivoting member, the first end of which is pivoted to the inner wall of one of the half shells;

a second pivoting member, a first end of which is pivoted to the inner wall of the other half shell, and a second end of the first pivoting member is pivoted with a second end of the second pivoting member;

the torsion spring is arranged at the pivot joint of the first pivoting piece and the second pivoting piece and used for providing tension for the first pivoting piece and the second pivoting piece;

preferably, the flexible partition comprises:

a first supporting piece, the first end of which is pivoted on the inner wall of one of the half shells;

a second supporting piece, the first end of which is pivoted with the inner wall of the other half shell;

a compression spring disposed between the second end of the first support member and the second end of the second support member to provide a supporting force for the first support member and the second support member.

Preferably, the torsion spring is made of a material affected by temperature so that its spring coefficient is reduced when the temperature is increased.

Preferably, the compression spring is made of a material that is affected by temperature, so that the spring constant of the compression spring decreases when the temperature increases.

Preferably, the second end of the second supporting member is provided with a guide groove, the second end of the first supporting member extends into the guide groove, and the pressure spring is arranged in the guide groove.

The half-shell material of the turbine blade comprises the following components in percentage by weight: c: 0.1-0.3%, Si: 5.5-7.5%, K: 0.2-0.5%, Sc: 0.2-0.5%, Al: 0.4-0.6%, Ti: 3.2-6.2%, Cu: 0.3-0.6%, Mo: 0.2-0.4%, Eu: 0.2-0.4% and the balance Fe.

The surface of the turbine blade half-shell material is coated with an anticorrosive paint, and the anticorrosive paint is composed of the following substances in parts by weight: 3-8 parts of ceramic soil, 6-12 parts of glass fiber, 3-8 parts of adipate, 3-8 parts of chlorosulfonated polyethylene rubber and 4-12 parts of 4- (1, 3-diphenylbutyl) -1, 2-xylene.

Compared with the prior art, the steam turbine blade disclosed by the invention has the beneficial effects that: the flexible dividing piece adapts to the deformation of the half shells through deformation, so that excessive strain and stress concentration cannot be generated at the joint of the two half shells or the joint of the half shells and the flexible dividing piece, and cracking of the two half shells at the joint or cracking of the half shells and the supporting piece at the joint can be effectively prevented. The half-shell material of the turbine blade has strong vibration attenuation resistance and wear resistance, and after the half-shell material is coated with the anticorrosive coating, the corrosion resistance, oxidation resistance and erosion resistance of the half-shell material are enhanced.

Drawings

FIG. 1 is a prior art profile view of a steam turbine blade.

FIG. 2 is a cross-sectional view of a prior art steam turbine blade.

FIG. 3 is a cross-sectional view of a steam turbine blade provided in accordance with an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a steam turbine blade provided in accordance with another embodiment of the present invention.

In the figure:

10-a blade; 11-half shell; 12-a flexible partition; 121-a first pivot; 122-a second pivot; 123-torsion spring; 124-a first support member; 125-a second support; 126-pressure spring; 13-cooling flow channel.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in fig. 3 and 4, an embodiment of the present invention discloses a steam turbine blade 10, the blade 10 including: two half-shells 11 and a flexible partition 12. The two half-shells 11 are butt-joined by welding or gluing to form the shape of the blade 10, and accordingly the blade 10 formed in this way has a cavity formed inside. A flexible partition member 12 is provided between the two half shells 11 to partition the space into the cooling flow passages 13, and in this embodiment, the flexible partition member 12 is provided at a position close to the front side of the blade 10 (where the temperature difference formed by the inner and outer walls of the half shells 11 is the largest and the corresponding deformation is also the largest) to partition the cooling flow passages 13 closer to the front side of the blade 10. It should be noted that: the cooling flow channel 13 extends from the root of the blade 10 to the tip of the blade 10, and a cooling medium, such as cold gas, flows from the root of the blade 10 to the tip of the blade 10 and flows out from the tip of the blade 10 (as well as the flow direction in the prior art). The flexible partition 12 is characterized in that: when the half shell 11 is deformed due to a large temperature difference between the inner wall and the outer wall of the half shell 11 caused by cooling, the flexible dividing member 12 adapts to the deformation of the half shell 11 by deformation (including shape change and/or length change), that is, there is no great limit to the deformation of the half shell 11 (whereas the rigid supporting member in the prior art has a great limit to the deformation of the half shell 11 due to no deformation), so that there is no excessive strain and stress concentration at the joint of the two half shells 11 or the joint of the half shell 11 and the flexible dividing member 12, and thus cracking of the two half shells 11 at the joint or cracking of the half shell 11 and the supporting member at the joint can be effectively prevented.

In a preferred embodiment of the present invention, as shown in fig. 3, the flexible dividing member 12 includes a first pivoting member 121, a second pivoting member 122, and a torsion spring 123. The first pivot element 121 and the second pivot element 122 are made of a material that is rigid against the temperature, the first end of the first pivot element 121 being pivoted to the inner wall of one of the half-shells 11; a first end of the second pivoting member 122 is pivoted to the inner wall of the other half shell 11, and a second end of the first pivoting member 121 is pivoted to a second end of the second pivoting member 122; the torsion spring 123 is disposed at the pivot joint of the first pivot member 121 and the second pivot member 122, and is used for providing tension for the first pivot member 121 and the second pivot member 122; and the first pivot member 121 is angled with respect to the second pivot member 122 when the blade 10 is not deformed. In the present embodiment, the torsion spring 123 provides tension to the first and

second pivoting members

121 and 122 so that the first and

second pivoting members

121 and 122 can support the blade 10. When the two half shells 11 of the blade 10 are deformed concavely due to the temperature difference, the first pivot member 121 and the second pivot member 122 accommodate the deformation by decreasing the included angle, and when the two half shells 11 of the blade 10 are deformed convexly due to the temperature difference, the first pivot member 121 and the second pivot member 122 accommodate the deformation by increasing the included angle. In a preferred embodiment, the torsion spring 123 is made of a material that is affected by temperature (e.g., the material is spring steel in which both austenite and martensite are present), such that the spring constant of the torsion spring 123 decreases as the temperature increases. In this preferred embodiment, when the temperature rises, the resistance of the torsion spring 123 to deformation of the half shell 11 due to the deformation of the elastic coefficient becomes smaller, so that the resistance to deformation of the half shell 11 can be more reduced.

In a preferred embodiment of the present invention, as shown in fig. 4, the flexible partition 12 comprises: a first support member 124, a second support member 125, and a compression spring 126. The first 124 and second 125 supports are made of a material that is rigid against the temperature, the first end of the first support 124 being pivoted to the inner wall of one of the half-shells 11; a first end of the second support element 125 is pivoted to the inner wall of the other half-shell 11; a compression spring 126 is disposed between the second end of the first supporting member 124 and the second end of the second supporting member 125 to provide a supporting force for the first supporting member 124 and the second supporting member 125. In the present embodiment, when the two half shells 11 of the blade 10 are deformed concavely due to the temperature difference, the total length of the first and second supporting

members

124 and 125 is reduced to accommodate the deformation, and when the two half shells 11 of the blade 10 are deformed convexly due to the temperature difference, the total length of the first and second supporting

members

124 and 125 is increased to accommodate the deformation. In a preferred embodiment, the compression spring 126 is made of a material that is affected by temperature (e.g., a spring steel material in which both austenite and martensite are present) such that the spring constant of the compression spring 126 decreases as the temperature increases. In this preferred embodiment, when the temperature rises, the resistance of the compression spring 126 to deformation of the half shell 11 due to the elastic coefficient deformation becomes smaller, so that the resistance to deformation of the half shell 11 can be further reduced. In order to improve the stability of the first supporting member 124 and the second supporting member 125, the second end of the second supporting member 125 is provided with a guide groove, the second end of the first supporting member 124 extends into the guide groove, and the compression spring 126 is disposed in the guide groove.

In order to increase the vibration damping capacity and the wear resistance of the steam turbine blade, the half-shell material of the steam turbine blade is optimized, and the half-shell material of the steam turbine blade consists of the following components in percentage by weight (experiment group 1): c: 0.2%, Si: 6.5%, K: 0.3%, Sc: 0.3%, Al: 0.5%, Ti: 4.2%, Cu: 0.4%, Mo: 0.3%, Eu: 0.3 percent and the balance of Fe.

Compared with the traditional turbine blade half-shell material, the invention adds Sc element and Eu element, in order to verify the effect of adding Sc element and Eu element and the abrasion performance, an abrasion experiment is carried out, and the following comparative experiment is carried out:

the half-shell material of the turbine blade is composed of the following components in percentage by weight (comparative group 1): c: 0.2%, Si: 6.5%, K: 0.3%, Al: 0.5%, Ti: 4.2%, Cu: 0.4%, Mo: 0.3%, Eu: 0.3 percent and the balance of Fe.

The half-shell material of the turbine blade is composed of the following components in percentage by weight (comparative group 2): c: 0.2%, Si: 6.5%, K: 0.3%, Sc: 0.3%, Al: 0.5%, Ti: 4.2%, Cu: 0.4%, Mo: 0.3 percent and the balance of Fe.

The half shell material of the turbine blade is composed of the following components in percentage by weight (comparative group 3): c: 0.2%, Si: 6.5%, K: 0.3%, Al: 0.5%, Ti: 4.2%, Cu: 0.4%, Mo: 0.3 percent and the balance of Fe.

In order to improve the wear resistance of the material, the half-shell material of the turbine blade is optimized, and is composed of the following components in percentage by weight (experiment group 2): c: 0.2%, Si: 6.5%, K: 0.3%, Sc: 0.3%, Al: 0.5%, Ti: 4.2%, Cu: 0.4%, Mo: 0.3%, Eu: 0.3 percent, Ga0.3 percent and the balance of Fe.

And in the abrasion experiment, an MLS-225 type wet rubber wheel abrasive abrasion tester is used for carrying out the abrasion experiment. Six 55X 25X 5mm wear patterns were taken from the turbine blade half shells of each test group, and the test parameters in the wear test were as follows: rotating speed of the rubber wheel: 240 rpm, rubber wheel diameter: 178mm, rubber wheel hardness: 60 (shore hardness), load: 10Kg, abrasion time: 250s, rubber wheel revolution: about 1000 revolutions, abrasive: 60-mesh quartz sand. The wear resistance of a material is measured by the weight loss of wear. Before and after the experiment, the test piece is put into a beaker filled with acetone solution and is cleaned in an ultrasonic cleaner for 5 minutes, Q235 steel is used as a comparison in the experiment, and the ratio of the weight loss of the comparison piece to the weight loss of the measurement piece is used as the relative wear resistance of the formula.

Relative abrasion resistance-standard pattern wear amount/pattern wear amount

The test results are shown in table 1:

TABLE 1

Note: represents P <0.05 compared to experimental groups; represents P < 0.01.

As can be seen from Table 1, the material of the invention has enhanced wear resistance as proved by the experimental group 1, which is much larger than 1, the comparison group 1-2 is significantly reduced compared to the experimental group 1, and proves that the Sc element and the Eu element are used in combination, the efficacy is the greatest, compared with the approximate Q235 steel of the group 3, the approximate Q235 steel is proved to have no Sc element and Eu element, the performance of the wear-resistant material is equivalent to that of the existing Q235 steel, the Sc element and the Eu element are key elements for improving the wear resistance, the wear resistance of the experimental group 2 is obviously improved compared with that of the experimental group 1, and the Ga is proved to have the effect of improving the wear resistance of the components.

In order to improve the corrosion resistance of the half shell of the turbine blade, the surface of the half shell is coated with an anticorrosive coating, and the anticorrosive coating is prepared from the following substances in parts by weight: 6 parts of ceramic clay, 8 parts of glass fiber, 5 parts of adipate, 6 parts of chlorosulfonated polyethylene rubber and 8 parts of 4- (1, 3-diphenylbutyl) -1, 2-xylene (experiment 1).

For comparison, the anticorrosive paint consists of the following substances in parts by weight: 6 parts of ceramic clay, 8 parts of glass fiber, 5 parts of adipate and 6 parts of chlorosulfonated polyethylene rubber (experiment 2).

Preferably, the anticorrosive paint consists of the following substances in parts by weight: 6 parts of ceramic clay, 8 parts of glass fiber, 5 parts of adipate, 6 parts of chlorosulfonated polyethylene rubber, 8 parts of 4- (1, 3-diphenylbutyl) -1, 2-xylene and 6 parts of 2-benzyl aziridine (experiment 3).

Selecting a turbine blade half-shell test piece with 30mmX20mm, coating the anticorrosive paint of experiments 1-3, soaking a coating film in 3.5% NaCl aqueous solution, and testing the self-corrosion current by adopting a CS350H electrochemical testing system, wherein the test result is shown in Table 2:

TABLE 2

Note: represents P <0.05 compared to experiment 1; represents P < 0.01.

As can be seen from table 2, the self-corrosion current of experiment 1 is significantly lower than that of the uncoated group and experiment 2, and the self-corrosion current of experiment 3 is significantly lower than that of experiment 1, which proves that the anticorrosive coating of the present invention can achieve significant anticorrosive efficacy.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.

Claims

1. A steam turbine blade, comprising:

two half-shells that snap together to form a cavity;

the flexible partition can change along with the deformation of the half shell to adapt to the shape change of the blade;

the flexible partition comprises:

or

The flexible partition comprises:

a compression spring disposed between a second end of the first support member and a second end of the second support member to provide a supporting force for the first support member and the second support member;

the turbine blade half shell is made of the following components in percentage by weight: c: 0.1-0.3%, Si: 5.5-7.5%, K: 0.2-0.5%, Sc: 0.2-0.5%, Al: 0.4-0.6%, Ti: 3.2-6.2%, Cu: 0.3-0.6%, Mo: 0.2-0.4%, Eu: 0.2-0.4% and the balance Fe.

2. The steam turbine blade according to claim 1, wherein the torsion spring is made of a material that is temperature-affected such that the spring coefficient of the torsion spring decreases as the temperature increases.

3. The steam turbine blade of claim 1, wherein the compression spring is made of a material that is temperature-affected such that the spring coefficient of the compression spring decreases as temperature increases.

4. The steam turbine blade of claim 1, wherein the second end of the second support member is provided with a guide groove, the second end of the first support member extends into the guide groove, and the compression spring is disposed in the guide groove.

5. The steam turbine blade of claim 1, wherein the surface of the steam turbine blade half shell material is coated with an anti-corrosive coating, the anti-corrosive coating comprising, in parts by weight: 3-8 parts of ceramic soil, 6-12 parts of glass fiber, 3-8 parts of adipate, 3-8 parts of chlorosulfonated polyethylene rubber and 4-12 parts of 4- (1, 3-diphenylbutyl) -1, 2-xylene.