Flange assembly, exhaust cylinder inner and outer heat insulation layer welding control method and exhaust cylinder

Abstract

The flange assembly comprises a first flange body and a second flange body, the first flange body comprises a first side plate, a sealing plate is fixedly arranged on one side of the first side plate, a first attaching plate is fixedly connected with the sealing plate, and a sealing groove is formed between the first side plate and the sealing plate; the first attaching plate is flush with the side, located in the sealing groove, of the first side plate. The second flange body comprises a second side plate, a second attaching plate is fixedly arranged at the end of one side of the second side plate, a limiting plate is fixedly arranged at the end, away from the second side plate, of the second attaching plate, and an extending part is fixedly arranged on the second attaching plate. When the flange assembly is installed, welding deformation is controlled by additionally arranging a shrinkage compensation process base plate and a flange assembly process back plate and formulating reasonable welding process parameters, and under the conditions that the process base plate is disassembled and then the upper half and the lower half of the carbon steel body are closed, a first side plate and a second side plate between the flange assembly abut against each other, and the gap of the flange assembly meets the requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbine exhaust cylinder manufacturing, in particular to a flange assembly, an exhaust cylinder inner and outer heat insulation layer welding control method and an exhaust cylinder. BACKGROUND

[0002] The exhaust cylinder is an important welded structural part of the gas turbine, directly contacts the high-temperature and high-speed gas after work, and the working environment of the stainless steel heat insulation layer as the airflow passage is extremely harsh. When the temperature exceeds 400 DEG C, the tensile strength and yield strength of the carbon steel body will decrease significantly, and if the carbon steel body directly contacts the high-temperature exhaust gas, the carbon steel body may be plastically deformed due to its own weight and exhaust pressure fluctuation. Therefore, the exhaust cylinder heat insulation layer is installed in the carbon steel body, and the heat insulation layer is composed of an inner heat insulation layer, an outer heat insulation layer and a wing-shaped body, and the gas passage is between the inner heat insulation layer and the outer heat insulation layer. The heat insulation layer can control the wall temperature of the carbon steel body to 150~250 DEG C, which fundamentally avoids the above-mentioned strength decrease and thermal fatigue problems.

[0003] In the prior art, Chinese patent document CN113084381A, published (announced) on July 9, 2021, discloses a gas turbine exhaust cylinder heat insulation layer assembly assembling tool and assembly welding method, which is made into a cylindrical heat insulation layer by welding. Due to the large temperature change in the exhaust cylinder, the heat insulation layer repeatedly bears thermal expansion and cold contraction, and there is a risk of cracking. SUMMARY

[0004] The purpose of the present application is to overcome the above technical deficiencies, provide a flange assembly, an exhaust cylinder inner and outer heat insulation layer welding control method and an exhaust cylinder, which divides the heat insulation layer into two halves in the axial direction for assembly, thereby avoiding cracking of the heat insulation layer.

[0005] To achieve the above technical purpose, the present application adopts the following technical scheme: A flange assembly, comprising a first flange body and a second flange body, the first flange body comprising a first side plate, a sealing plate being fixedly arranged on one side of the first side plate, a first abutting plate being fixedly connected with the sealing plate, a sealing groove being arranged between the first side plate and the sealing plate, the first abutting plate and the first side plate being flush on one side of the sealing groove; the second flange body comprising a second side plate, a second abutting plate being fixedly arranged on the end of one side of the second side plate, a limiting plate being fixedly arranged on the end of the second abutting plate away from the second side plate, and a protruding portion being fixedly arranged on the second abutting plate; in use, the protruding portion is inserted into the sealing groove, and the first side plate and the second side plate are butted.

[0006] The first bonding plate is provided with a plurality of first stress holes and first stress notches at axial intervals, and the first stress notches correspond one-to-one with the first stress holes; the second bonding plate is provided with a plurality of second stress holes and second stress notches at axial intervals, and the second stress holes correspond one-to-one with the second stress notches, and the second stress notches penetrate through the limiting plate.

[0007] A welding control method for the inner and outer heat insulation layers of an exhaust cylinder is provided for installing the flange assembly onto the inner and outer heat insulation layers of the exhaust cylinder. The control method includes controlling the machining accuracy of the flange assembly, controlling the assembly gap between the flange assembly and the heat insulation layer cylinder, and controlling welding deformation.

[0008] The method for controlling the machining accuracy of the flange assembly is as follows: The raw material for manufacturing flange assemblies is set as a T-shaped blank to reduce the amount of machining and reduce machining deformation, thereby controlling the machining dimensional accuracy.

[0009] The method for controlling the assembly gap between the flange assembly and the insulation layer cylinder is as follows: A process pad is placed on the lower half of the carbon steel body of the exhaust cylinder. After the upper and lower halves of the carbon steel body are closed, there is a gap of the process pad thickness between the first flange body and the second flange body of the flange assembly. When the carbon steel body of the exhaust cylinder is assembled in half, the assembly dimensions of the flange assembly are adjusted by grinding the heat insulation layer cylinder. With the upper and lower halves of the carbon steel body of the exhaust cylinder joined together and a process pad installed, there is no gap between the first and second side plates of the flange assembly.

[0010] The welding deformation control method is as follows: Process back plates are welded at intervals on the flange assemblies of the inner and outer insulation layers of the exhaust cylinder, and the process back plates are welded to the inner and outer insulation layers to control the welding deformation of the inner and outer insulation layers. After the welding of the inner and outer insulation layers is completed, the process back plates are removed. The process backplate includes an outer heat insulation backplate and an inner heat insulation backplate. Both the outer heat insulation backplate and the inner heat insulation backplate are arc-shaped. The outer arc surface of the outer heat insulation backplate is provided with two first clearance grooves, and the inner arc surface of the inner heat insulation backplate is provided with two second clearance grooves.

[0011] When the first and second side plates between the flange assemblies are welded to the outer and inner insulation layers, flux-cored wire CO2 gas shielded welding is used with a current of 180~200A and a voltage of 26~28V. Symmetrical segmented skip welding is performed, alternating between the upper and lower halves of the carbon steel body of the exhaust cylinder, until the butt weld between the flange assembly and the outer and inner insulation layers is completed. During the welding process, a rubber hammer is used to evenly tap the cylinder near the weld to release some of the welding stress.

[0012] Symmetrical segmented skip welding refers to dividing the weld into multiple sections and welding them symmetrically and alternately along the circumference, with each section having a welding length of no more than 150mm.

[0013] The process pad is made of 6mm aluminum plate by water jet cutting. The process pad has multiple through holes. The shape of the process pad and the position of each through hole match the outline and hole position of the outer half surface of the carbon steel body of the exhaust cylinder.

[0014] An exhaust cylinder employs the aforementioned flange assembly, wherein the outer heat insulation layer and the inner heat insulation layer of the exhaust cylinder are sealed by a first flange body and a second flange body.

[0015] The present invention, which adopts the above technical solution, has the following prominent features compared with the prior art: 1. In this invention, one side of the first side plate of the flange assembly is used to adhere to the second side plate, and the other side of the first side plate is used to weld to one end of one half of the insulation layer. Similarly, the second side plate is located on one side of the second bonding plate and is used to adhere to the first side plate, and the other side of the second side plate is used to weld to one end of the other half of the insulation layer. During installation, the protruding part is inserted into the sealing groove, thereby forming an axially split and closed cylindrical structure of the insulation layer. The limiting plate is used to hook the half-face of the two halves of the carbon steel body, thereby limiting the flange assembly and preventing the flange assembly from falling off.

[0016] 2. During installation, the flange assembly of the present invention controls welding deformation by adding a shrinkage compensation process pad and a flange assembly process back plate, and by formulating reasonable welding process parameters. After removing the process pad and closing the upper and lower halves of the carbon steel body, the first side plate and the second side plate of the flange assembly abut against each other, and the gap of the flange assembly meets the requirements. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0018] Figure 1 This is a three-dimensional schematic diagram of the first flange body in this invention.

[0019] Figure 2 This is a three-dimensional schematic diagram of the second flange body in this invention.

[0020] Figure 3 This is a schematic diagram of the first flange body and the second flange body combined to form a flange assembly in this invention.

[0021] Figure 4 This is a schematic cross-sectional view of the T-shaped blank of the first flange body in this invention.

[0022] Figure 5This is a schematic cross-sectional view of the T-shaped blank of the second flange body in this invention.

[0023] Figure 6 This is a schematic diagram of the process pad in this invention.

[0024] Figure 7 This is a schematic diagram of the outer heat insulation layer back plate in this invention.

[0025] Figure 8 This is a schematic diagram of the inner insulation layer back plate in this invention.

[0026] Figure 9 This is a schematic diagram of installing a process pad on an exhaust cylinder.

[0027] Figure 10 A schematic diagram showing the installation of an outer heat insulation backplate and an inner heat insulation backplate on the exhaust cylinder heat insulation layer.

[0028] Figure 11 for Figure 10 A schematic diagram of the structure of section AA in the middle.

[0029] Figure 12 This is a three-dimensional schematic diagram of the exhaust cylinder of the present invention.

[0030] Figure Labels First flange body T-shaped blank 1, second flange body T-shaped blank 2, exhaust cylinder 3, outer heat insulation layer 4, inner heat insulation layer 5; First flange body 10, first side plate 11, sealing plate 12, sealing groove 13, first bonding plate 14, first stress hole 15, first stress notch 16; Second flange body 20, second side plate 21, second bonding plate 22, limiting plate 23, protrusion 24, second stress hole 25, second stress notch 26; Process backing plate 30, through hole 31; External insulation back panel 40, first clearance groove 41; Inner insulation layer back panel 50, second clearance groove 51. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] Example 1: Please see Figure 1 , 23. A flange assembly, comprising a first flange body 10 and a second flange body 20. The first flange body 10 includes a first side plate 11, a sealing plate 12 fixedly disposed on one side of the first side plate 11, a first bonding plate 14 fixedly connected to the sealing plate 12, a sealing groove 13 provided between the first side plate 11 and the sealing plate 12, and the first bonding plate 14 being flush with the first side plate 11 on one side of the sealing groove 13. The second flange body 20 includes a second side plate 21, a second bonding plate 22 fixedly disposed at one end of one side of the second side plate 21, a limiting plate 23 fixedly disposed at one end of the second bonding plate 22 away from the second side plate 21, and a protrusion 24 fixedly disposed on the second bonding plate 22. In use, the protrusion 24 is inserted into the sealing groove 13, and the first side plate 11 and the second side plate 21 are joined together.

[0033] Combination Figure 3 One side of the first side plate 11 is used to fit against the second side plate 21, and the other side of the first side plate 11 is used to weld to one end of one half of the insulation layer. Similarly, the second side plate 21 is located on one side of the second bonding plate 22 and is used to fit against the first side plate 11, and the other side of the second side plate 21 is used to weld to one end of the other half of the insulation layer. During installation, the protrusion 24 is inserted into the sealing groove 13, thereby forming a cylindrical structure in which the insulation layer is axially separated and closed. The limiting plate 23 is used to hook the half face of the two halves of the carbon steel body, thereby limiting the flange assembly and preventing the flange assembly from falling off.

[0034] Furthermore, the first bonding plate 14 is provided with a plurality of first stress holes 15 and first stress notches 16 axially spaced apart, with each first stress notch 16 corresponding to a first stress hole 15; the second bonding plate 22 is provided with a plurality of second stress holes 25 and second stress notches 26 axially spaced apart, with each second stress hole 25 corresponding to a second stress notch 26, and the second stress notch 26 penetrates the limiting plate 23. This structure prevents uneven heating of the first flange body 10 and the second flange body 20 from causing deformation and cracking.

[0035] Example 2: After the two halves of the exhaust cylinder are joined, the gap between the first flange body 10 and the second flange body 20 in the flange assembly has high requirements, necessitating strict airtightness. Because the insulation layer has an irregular shape and is made entirely of austenitic stainless steel, its dimensions are difficult to control during assembly, and significant shrinkage deformation occurs after welding. Therefore, appropriate assembly methods and welding processes must be adopted to ensure that the gap in the flange assembly meets the requirements after the two halves of the exhaust cylinder are joined.

[0036] To this end, the present invention also proposes a welding control method for the inner and outer heat insulation layers of an exhaust cylinder, which is used to install the flange assembly onto the inner and outer heat insulation layers of the exhaust cylinder. The control method includes control of the processing accuracy of the flange assembly, control of the assembly gap between the flange assembly and the heat insulation layer cylinder, and control of welding deformation.

[0037] The first flange body 10 and the second flange body 20 are both irregular structures. The level of machining accuracy and the magnitude of deformation after machining will affect the assembly dimensions and final positioning accuracy of the flange assembly.

[0038] First, the blank structures of the first flange body 10 and the second flange body 20 need to be optimized.

[0039] See Figure 4 This is a cross-sectional schematic diagram of the first flange body T-shaped blank 1 in this invention.

[0040] See Figure 5 This is a cross-sectional schematic diagram of the second flange body T-shaped blank 2 in this invention.

[0041] The raw material for manufacturing flange assemblies is set as a T-shaped blank to reduce the amount of machining and reduce machining deformation, thereby controlling the machining dimensional accuracy.

[0042] Second, increase the amount of welding shrinkage compensation.

[0043] A process pad 30 is placed on the lower half of the outer half-face of the carbon steel body of the exhaust cylinder 3. The structure of the process pad 30 is as follows: Figure 6 As shown, after the upper and lower halves of the carbon steel body are closed, there is a gap of the thickness of the process pad 30 between the first flange body 10 and the second flange body 20 of the flange assembly. When the carbon steel body of the exhaust cylinder is assembled in half, the assembly dimensions of the flange assembly are adjusted by grinding the heat insulation layer cylinder. With the upper and lower halves of the carbon steel body of the exhaust cylinder 3 closed and the process pad 30 installed, there is no gap between the first side plate 11 and the second side plate 21 of the flange assembly.

[0044] In this embodiment, see Figure 9 A 6mm process pad 30 is placed on the lower half of the carbon steel body's outer half surface. After the upper and lower halves are closed, theoretically there will be a 6mm gap between the first flange body 10 and the second flange body 20 of the flange assembly. During the half-assembly, the assembly size of the flange assembly is adjusted by grinding the heat insulation layer cylinder. Under the premise of ensuring an assembly gap of 2-4mm, the first flange body 10 and the second flange body 20 are each installed 3mm beyond the theoretical size. That is, when the carbon steel body is equipped with the process pad 30, the first flange body 10 and the second flange body 20 are ensured to have no gap after the upper and lower halves of the exhaust cylinder 3 are closed.

[0045] Specifically, using the carbon steel body's half-face as a reference, install the flange assembly, place a 6mm tooling gasket 30 on the outer half-face of the carbon steel body, and then join the two halves of the carbon steel body together.

[0046] Next, process backplates are installed on the flange assemblies of the inner and outer insulation layers at 300mm intervals, such as... Figure 10 ,11 As shown.

[0047] Specifically, the process back plate is welded to the inner and outer insulation layers, and the welding deformation of the inner and outer insulation layers is controlled. After the welding of the inner and outer insulation layers is completed, the process back plate is removed.

[0048] See Figure 7 , 8 9, 10, 11, The process back plate includes an outer heat insulation back plate 40 and an inner heat insulation back plate 50. Both the outer heat insulation back plate 40 and the inner heat insulation back plate 50 are arc-shaped. The outer arc surface of the outer heat insulation back plate 40 is provided with two first clearance grooves 41, and the inner arc surface of the inner heat insulation back plate 50 is provided with two second clearance grooves 51.

[0049] The curvature of the outer insulation layer back plate 40 and the inner insulation layer back plate 50 is designed according to the curvature of the inner and outer insulation layers. The first clearance groove 41 and the second clearance groove 51 are used to avoid the weld between the flange assembly and the insulation layer.

[0050] Furthermore, when the first side plate 11 and the second side plate 21 between the flange assemblies are welded to the outer heat insulation layer 4 and the inner heat insulation layer 5, flux-cored wire CO2 gas shielded welding is used with a current of 180~200A and a voltage of 26~28V. Symmetrical segmented skip welding is performed, and welding is carried out alternately between the upper and lower halves of the carbon steel body of the exhaust cylinder 3 until the butt weld between the flange assembly and the outer heat insulation layer 4 and the inner heat insulation layer 5 is completed. During the welding process, a rubber hammer is used to evenly tap the cylinder near the weld to release some of the welding stress.

[0051] Symmetrical segmented skip welding refers to dividing the weld into multiple sections and welding them symmetrically and alternately along the circumference, with each section having a welding length of no more than 150mm.

[0052] The process pad 30 is made of 6mm aluminum plate by water cutting. The process pad 30 is provided with multiple through holes 31. The shape of the process pad 30 and the hole positions of each through hole 31 match the outline and hole positions of the carbon steel body of the exhaust cylinder 3.

[0053] In this embodiment, see Figure 11 Process back plates are installed on the inner and outer insulation layer flange assemblies respectively. There are 12 plates in total, with 6 plates on each side of the inner cylinder and 16 plates in total, with 8 plates on each side of the outer cylinder.

[0054] This solution controls welding deformation by adding a shrinkage compensation process pad 30 and a flange assembly process back plate, and by formulating reasonable welding process parameters. After removing the process pad 30 and then closing the upper and lower halves of the carbon steel body, the first side plate 11 and the second side plate 21 of the flange assembly abut against each other, and the gap of the flange assembly meets the requirements.

[0055] Example 3: Based on Embodiment 1 or Embodiment 2, the present invention also discloses an exhaust cylinder 3, see [link to embodiment 1]. Figure 12 This exhaust cylinder uses a flange assembly as described in Example 1. The outer heat insulation layer 4 and the inner heat insulation layer 5 of the exhaust cylinder 3 are closed by the first flange body 10 and the second flange body 20.

[0056] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the invention. Modifications and variations made by those skilled in the art in accordance with the spirit of the invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A flange assembly, characterized in that: The flange includes a first flange body (10) and a second flange body (20). The first flange body (10) includes a first side plate (11). A sealing plate (12) is fixedly provided on one side of the first side plate (11). A first bonding plate (14) is fixedly connected to the sealing plate (12). A sealing groove (13) is provided between the first side plate (11) and the sealing plate (12). The first bonding plate (14) is flush with the first side plate (11) on one side of the sealing groove (13). The second flange body (20) includes a second side plate (21). A second bonding plate (22) is fixedly provided at one end of one side of the second side plate (21). A limiting plate (23) is fixedly provided at one end of the second bonding plate (22) away from the second side plate (21). A protrusion (24) is fixedly provided on the second bonding plate (22). In use, the protrusion (24) is inserted into the sealing groove (13), and the first side plate (11) and the second side plate (21) are connected.

2. The flange assembly according to claim 1, characterized in that: The first bonding plate (14) is provided with a plurality of first stress holes (15) and first stress notches (16) axially spaced apart, and the first stress notches (16) correspond one-to-one with the first stress holes (15); the second bonding plate (22) is provided with a plurality of second stress holes (25) and second stress notches (26) axially spaced apart, the second stress holes (25) correspond one-to-one with the second stress notches (26), and the second stress notches (26) penetrate the limiting plate (23).

3. A method for controlling the welding of inner and outer heat insulation layers of an exhaust cylinder, characterized in that, The method for installing the flange assembly as described in claim 1 onto the inner and outer heat insulation layers of the exhaust cylinder includes control of the flange assembly machining accuracy, control of the assembly gap between the flange assembly and the heat insulation layer cylinder, and control of welding deformation.

4. The welding control method for the inner and outer heat insulation layers of the exhaust cylinder according to claim 3, characterized in that: The method for controlling the machining accuracy of the flange assembly is as follows: The raw material for manufacturing flange assemblies is set as a T-shaped blank to reduce the amount of machining and reduce machining deformation, thereby controlling the machining dimensional accuracy.

5. The welding control method for the inner and outer heat insulation layers of the exhaust cylinder according to claim 4, characterized in that: The method for controlling the assembly gap between the flange assembly and the insulation layer cylinder is as follows: A process pad (30) is placed on the lower half of the outer half of the carbon steel body of the exhaust cylinder (3). After the upper and lower halves of the carbon steel body are closed, there is a gap of the thickness of the process pad (30) between the first flange body (10) and the second flange body (20) of the flange assembly. When the carbon steel body of the exhaust cylinder (3) is assembled in half, the assembly dimensions of the flange assembly are adjusted by grinding the heat insulation layer cylinder. With the upper and lower halves of the carbon steel body of the exhaust cylinder (3) closed and equipped with a process pad (30), there is no gap between the first side plate (11) and the second side plate (21) of the flange assembly.

6. The welding control method for the inner and outer heat insulation layers of the exhaust cylinder according to claim 5, characterized in that: The welding deformation control method is as follows: Process back plates are welded at intervals on the flange assembly of the inner and outer heat insulation layers of the exhaust cylinder (3), and the process back plates are welded to the inner and outer heat insulation layers to control the welding deformation of the inner and outer heat insulation layers. After the inner and outer heat insulation layers are welded, the process back plates are removed. The process back plate includes an outer heat insulation back plate (40) and an inner heat insulation back plate (50). Both the outer heat insulation back plate (40) and the inner heat insulation back plate (50) are arc-shaped. The outer arc surface of the outer heat insulation back plate (40) is provided with two first clearance grooves (41), and the inner arc surface of the inner heat insulation back plate (50) is provided with two second clearance grooves (51).

7. The welding control method for the inner and outer heat insulation layers of the exhaust cylinder according to claim 6, characterized in that: When the first side plate (11) and the second side plate (21) between the flange assemblies are welded to the outer heat insulation layer (4) and the inner heat insulation layer (5), the flux-cored wire CO2 gas shielded welding is used with a current of 180~200A and a voltage of 26~28V. Symmetrical segmented skip welding is performed, and welding is carried out alternately between the upper and lower halves of the carbon steel body of the exhaust cylinder (3) until the butt weld between the flange assembly and the outer heat insulation layer (4) and the inner heat insulation layer (5) is completed. During the welding process, a rubber hammer is used to evenly tap the cylinder near the weld to release some of the welding stress.

8. The welding control method for the inner and outer heat insulation layers of the exhaust cylinder according to claim 7, characterized in that: Symmetrical segmented skip welding refers to dividing the weld into multiple sections and welding them symmetrically and alternately along the circumference, with each section having a welding length of no more than 150mm.

9. The welding control method for the inner and outer heat insulation layers of the exhaust cylinder according to claim 5, characterized in that: The process pad (30) is made of 6mm aluminum plate by water cutting. The process pad (30) is provided with multiple through holes (31). The shape of the process pad (30) and the hole positions of each through hole (31) match the outline and hole positions of the carbon steel body of the exhaust cylinder (3).

10. An exhaust cylinder (3), characterized in that: The flange assembly described in claim 1 is used, wherein the outer heat insulation layer (4) and the inner heat insulation layer (5) of the exhaust cylinder (3) are closed by the first flange body (10) and the second flange body (20) through the connection and sealing.

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