A compact embedded exhaust casing structure for a steam turbine

Abstract

The application discloses a steam turbine embedded compact exhaust cylinder structure and belongs to the technical field of cylinder structure. In order to solve the problem that the existing compact single-cylinder steam turbine is difficult to complete high-power energy conversion due to limited axial space, the exhaust cylinder structure comprises an exhaust volute and a cylinder body, the rear X-stage cylinder body structure in the cylinder body extends into the exhaust volute structure of the exhaust cylinder, and the rear X-stage cylinder body structure and the exhaust volute structure are supported through a support unit. Considering that the end of the cylinder body needs to extend into the exhaust volute, the traditional bolt connection will interfere, therefore, the application replaces the traditional bolt connection with a key connection mode, on the basis of ensuring accurate positioning and reliable connection, the end of the cylinder body can be effectively prevented from being subjected to an opening angle and deformation. The application is used as an exhaust cylinder structure in a steam turbine.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cylinder structure, and particularly relates to a turbine embedded compact exhaust cylinder structure. BACKGROUND

[0002] In the design process of the cylinder flow part, in order to ensure that the steam is effectively expanded in a cylinder to do work and convert kinetic energy into mechanical energy, the length and the number of stages of the blade are key indicators. Long blades can make the steam expand and do work more fully in a single stage, but too long blades will lead to poor strength, large radial size and other problems. Therefore, in order to improve the efficiency of the turbine, the method of increasing the number of stages of the blade is usually adopted. However, in a single cylinder turbine, the more the number of stages, the greater the demand for the axial space of the cylinder. Therefore, in a compact single cylinder turbine with limited axial space, it is difficult to complete the conversion of high power. SUMMARY

[0003] The present application is to solve the problem that it is difficult to complete the conversion of high power in a compact single cylinder turbine with limited axial space, and further provides a turbine embedded compact exhaust cylinder structure.

[0004] The turbine embedded compact exhaust cylinder structure comprises an exhaust volute and a cylinder body. The rear X-stage cylinder structure in the cylinder body extends into the exhaust volute structure of the exhaust cylinder, and the rear X-stage cylinder structure and the exhaust volute structure are supported by a support unit.

[0005] Further, the value of X in the rear X-stage cylinder structure ranges from 1 to 3.

[0006] Further, the support unit comprises 2N support rods, where N is a positive integer. The 2N support rods are equidistantly arranged between the rear X-stage cylinder structure and the exhaust volute structure in the circumferential direction, and one end of each support rod is welded and fixed to the end of the rear X-stage cylinder structure, and the other end of each support rod is welded and fixed to the inner end wall of the exhaust volute structure.

[0007] Further, the cylinder body is a split structure, comprising an upper half cylinder and a lower half cylinder. The end cylinder of the upper half cylinder and the end cylinder of the lower half cylinder are fixed by two key units.

[0008] Further, the two key units are symmetrically arranged on the splicing surface of the upper half cylinder and the lower half cylinder along the axis of the cylinder body, and the top of each key unit is embedded in the end cylinder of the upper half cylinder, and the bottom of each key unit is embedded in the end cylinder of the lower half cylinder.

[0009] Further, the key unit comprises a longitudinal key and an axial key. The length extension direction of the longitudinal key is perpendicular to the axis of the cylinder body, and the length extension direction of the axial key is the same as the extension direction of the axis of the cylinder body.

[0010] Further, the 2N support rods are evenly divided into two support rod groups, and the two support rod groups are symmetrically arranged along the splicing surface of the upper half cylinder and the lower half cylinder, the upper support rod group is located between the end cylinder body and the exhaust volute structure of the upper half cylinder, and the lower support rod group is located between the end cylinder body and the exhaust volute structure of the lower half cylinder.

[0011] Further, the value range of N is 3-5.

[0012] Further, the axis of the support rod is arranged in parallel with the axis of the cylinder body.

[0013] The beneficial effects of the present application relative to the prior art are:

[0014] 1. The embedded compact exhaust cylinder structure of the steam turbine provided by the present application, compared with the traditional cylinder structure, while ensuring the exhaust area, the last few cylinder bodies are embedded into the exhaust volute, so that the steam turbine can realize large power conversion while minimizing the axial distance of the cylinder body, and the compact single-cylinder steam turbine with limited axial space can also complete large power energy conversion.

[0015] 2. The embedded compact exhaust cylinder structure of the steam turbine provided by the present application optimizes the connection mode of the cylinder body according to the design requirements, considering that the end of the cylinder body needs to extend into the exhaust volute, and there is no space for installing bolts, therefore, the present application uses a key connection mode to replace the traditional bolt connection, which can effectively prevent the end of the cylinder body from having an opening angle and deformation while ensuring accurate positioning and reliable connection.

[0016] 3. The embedded compact exhaust cylinder structure of the steam turbine provided by the present application, wherein the exhaust cylinder structure adopts a single-cylinder design, which has relatively low processing cost and relatively short processing period, and is very economical. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a schematic view of the internal structure of the embedded compact exhaust cylinder structure of the present application (the view is from the upper half cylinder direction with the splicing surface of the upper and lower cylinder bodies as the dividing plane);

[0018] In the figure, 1 is an exhaust volute, 2 is a rear X-stage cylinder body structure, 3 is a support rod, 4 is a longitudinal key, and 5 is an axial key. DETAILED DESCRIPTION

[0019] Specific implementation one: combined with Figure 1 In this embodiment, an embedded compact exhaust cylinder structure of a steam turbine is provided, the exhaust cylinder structure includes an exhaust volute 1 and a cylinder body, a rear X-stage cylinder body structure 2 in the cylinder body extends into the exhaust volute structure 1 of the exhaust cylinder, and the rear X-stage cylinder body structure 2 and the exhaust volute structure 1 are supported by a support unit.

[0020] The exhaust cylinder structure provided in the embodiment can guarantee the exhaust area, embed the rear X-stage cylinder structure 2 in the exhaust volute, and make the compact single-cylinder steam turbine with limited axial space complete high-power energy conversion, so that the steam is more fully expanded and does work in the single-cylinder steam turbine body.

[0021] Specific embodiment two: in combination Figure 1 The embodiment is described. The difference between the embodiment and the specific embodiment one is that the value range of X in the rear X-stage cylinder structure 2 is 1-3. The other components and connection modes are the same as those of the specific embodiment one.

[0022] Specific embodiment three: in combination Figure 1 The embodiment is described. The difference between the embodiment and the specific embodiment two is that the support unit includes 2N support rods 3, N is a positive integer, the 2N support rods 3 are equidistantly arranged between the rear X-stage cylinder structure 2 and the exhaust volute structure 1 in the circumferential direction, one end of each support rod 3 is welded and fixed to the end of the rear X-stage cylinder structure 2, and the other end of each support rod 3 is welded and fixed to the inner end wall of the exhaust volute structure 1. The other components and connection modes are the same as those of the specific embodiment two.

[0023] In the embodiment, the rear X-stage cylinder structure 2 is a cantilever support structure in the exhaust volute structure 1, and vibration occurs during the operation of the steam turbine, which affects the stability of the steam turbine. Therefore, the support rod structure is used as the support structure between the exhaust volute structure 1 and the rear X-stage cylinder structure 2, to improve the cantilever strength of the rear X-stage cylinder structure 2 and ensure the stability during operation.

[0024] Specific embodiment four: in combination Figure 1 The embodiment is described. The difference between the embodiment and the specific embodiment three is that the cylinder body is a split structure, the cylinder body includes an upper half cylinder and a lower half cylinder, and the end cylinder of the upper half cylinder and the end cylinder of the lower half cylinder are fixed by two key units. The other components and connection modes are the same as those of the specific embodiment three.

[0025] Specific embodiment five: in combination Figure 1 The embodiment is described. The difference between the embodiment and the specific embodiment four is that the two key units are symmetrically arranged on the splicing surface of the upper half cylinder and the lower half cylinder along the axis of the cylinder body, and the top of each key unit is embedded in the end cylinder of the upper half cylinder, and the bottom of each key unit is embedded in the end cylinder of the lower half cylinder. The other components and connection modes are the same as those of the specific embodiment four.

[0026] Specific embodiment six: in combination Figure 1The embodiment is different from the fifth embodiment in that the key unit comprises a longitudinal key 4 and an axial key 5, the longitudinal key 4 is arranged perpendicularly to the axis of the cylinder body, and the axial key 5 is arranged along the axis of the cylinder body.

[0027] As described in the fourth embodiment to the sixth embodiment, the key connection is used to replace the traditional bolt connection, so that the work space for installing the bolt is not required, the positioning is accurate, the connection is reliable, and the deformation of the cylinder end is effectively prevented.

[0028] The seventh embodiment is described in combination with the sixth embodiment. Figure 1 The embodiment is different from the seventh embodiment in that the 2N support rods 3 are divided into two support rod groups, the two support rod groups are arranged symmetrically along the joint surface of the upper half cylinder and the lower half cylinder, the upper support rod group is arranged between the end cylinder of the upper half cylinder and the exhaust volute structure 1, and the lower support rod group is arranged between the end cylinder of the lower half cylinder and the exhaust volute structure 1. The other components and connection modes are the same as those in the seventh embodiment.

[0029] The eighth embodiment is described in combination with the seventh embodiment. Figure 1 The embodiment is different from the seventh embodiment in that the value of N is 3-5. The other components and connection modes are the same as those in the eighth embodiment.

[0030] The ninth embodiment is described in combination with the eighth embodiment. Figure 1 The embodiment is different from the eighth embodiment in that the axis of the support rod is arranged perpendicularly to the axis of the cylinder body. The other components and connection modes are the same as those in the ninth embodiment.

[0031] The application has been described above with reference to the preferred embodiments, but is not intended to limit the application. Any person skilled in the art can make some changes or modifications to the above-mentioned structures and technical contents without departing from the scope of the technical solutions of the application, and the equivalent embodiments with equivalent changes are obtained. However, any simple modification, equivalent change and modification of the above-mentioned embodiments based on the technical essence of the application are still within the scope of the technical solutions of the application.

[0032] Working principle

[0033] The application is assembled according to the connecting relationship described in the first embodiment to the tenth embodiment when in use. During the operation of the steam turbine, steam passes through the rear X-stage embedded cylinder structure 2 and enters the exhaust volute structure 1, which ensures the exhaust area while reducing the axial distance. The cooperation of the longitudinal key 4 and the axial key 5 can avoid the opening angle and deformation of the embedded structure when connecting the upper and lower cylinders. The upper and lower half cylinders at the end of the rear X-stage embedded cylinder structure 2 are respectively provided with four support rods to ensure the strength of the cantilever structure of the embedded part.

Claims

1. A steam turbine embedded compact exhaust casing structure, the exhaust casing structure comprising an exhaust volute structure (1) and a casing body, characterized in that: The rear X-stage cylinder structure (2) in the cylinder block extends into the exhaust volute structure (1), and the rear X-stage cylinder structure (2) and the exhaust volute structure (1) are supported by a support unit; The support unit comprises 2N support rods (3), N being a positive integer, the 2N support rods (3) being equidistantly arranged between the rear X-stage cylinder structure (2) and the exhaust volute structure (1) in the circumferential direction, and one end of each support rod (3) being welded and fixed to the end of the rear X-stage cylinder structure (2), and the other end of each support rod (3) being welded and fixed to the inner end wall of the exhaust volute structure (1); The cylinder block is of a split structure, and comprises an upper half cylinder and a lower half cylinder, and the end cylinder of the upper half cylinder and the end cylinder of the lower half cylinder are fixed by two key units; The key unit comprises a longitudinal key (4) and an axial key (5), the length extension direction of the longitudinal key (4) is perpendicular to the axis of the cylinder block, and the length extension direction of the axial key (5) is the same as the axis extension direction of the cylinder block; The value range of X in the rear X-stage cylinder structure (2) is 1-3; The two key units are symmetrically arranged on the splicing surface of the upper half cylinder and the lower half cylinder along the axis of the cylinder block, and the top of each key unit is embedded in the end cylinder of the upper half cylinder, and the bottom of each key unit is embedded in the end cylinder of the lower half cylinder; The axis of the support rod is parallel to the axis of the cylinder block.

2. A compact nested exhaust casing structure for a steam turbine according to claim 1, characterized in that: The 2N support rods (3) are averagely divided into two support rod groups, and the two support rod groups are symmetrically arranged on the splicing surface of the upper half cylinder and the lower half cylinder, the upper support rod group is located between the end cylinder of the upper half cylinder and the exhaust volute structure (1), and the lower support rod group is located between the end cylinder of the lower half cylinder and the exhaust volute structure (1).

3. A compact nested exhaust casing structure for a steam turbine according to claim 2, characterized in that: The value range of N is 3-5.

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