A method for controlling the axial clearance between the extraction ring cavities of the inner cylinder of a red sleeve

Abstract

A method for controlling the axial clearance between the extraction ring cavity and the inner cylinder of a high-pressure cylinder with a red sleeve is disclosed. This invention addresses the problem of air leakage and ring cavity damage caused by axial clearance between the inner cylinder and the extraction ring cavity during assembly in existing high-pressure cylinder structures with red sleeves. The invention comprises the following steps: Step 1: Dimensional inspection of the extraction ring cavity and two red sleeve rings before assembly; Step 2: Simulated assembly inspection; Step 3: Assembly of the #5 red sleeve ring; Step 4: Assembly of the extraction ring cavity and the #6 red sleeve ring; Step 41: After heating, the extraction ring cavity and the #6 red sleeve ring are sequentially assembled onto the high-pressure inner cylinder; Step 42: When there is still a clearance between the #6 red sleeve ring and the high-pressure inner cylinder in the diametrical direction, six set screw tools are installed on the outer circumferential side of the high-pressure inner cylinder, and the set screw tools are tightened to achieve zero clearance between the end faces of the extraction ring cavity and the end faces of the red sleeve rings, while simultaneously pre-compressing the extraction ring cavity. This invention is used for controlling the axial clearance.

Description

Technical Field

[0001] This invention relates to a method for controlling axial clearance, specifically a method for controlling the axial clearance between the extraction ring cavities of the inner cylinder of a red sleeve. Background Technology

[0002] The turbine units of the new 1,000 MW and new 660 MW thermal power projects generally adopt a red-sleeved high-pressure inner cylinder structure. The high-pressure inner cylinder is equipped with an extraction steam ring cavity structure, which is a complete ring structure that is fitted onto the high-pressure inner cylinder. At the same time, the two ends of the extraction steam ring cavity are fitted with the interference-fitted red sleeve ring, using an end-face sealing method, requiring no clearance on the axial mating surface. However, in the existing red-sleeved high-pressure inner cylinder structure, during assembly, because the red sleeve ring is in a high-temperature expansion state after heating and fitting, axial clearance often exceeds the tolerance after cooling. This can easily lead to gaps on the axial mating surface between the red sleeve inner cylinder and the extraction steam ring cavity, resulting in problems such as air leakage and ring cavity damage.

[0003] In summary, the existing red-sleeved high-pressure inner cylinder structure is prone to gaps in the axial mating surface between the red-sleeved inner cylinder and the extraction ring cavity during assembly, which can lead to air leakage and ring cavity damage. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that, during assembly, existing high-pressure inner cylinder structures with red sleeves easily lead to gaps in the axial mating surfaces between the inner cylinder and the extraction ring cavity, resulting in air leakage and ring cavity damage. Therefore, this invention provides a method for controlling the axial gap between the inner cylinder and the extraction ring cavity.

[0005] The technical solution of the present invention is: a method for controlling the axial clearance between the steam extraction ring cavities of the inner cylinder of the red sleeve, which includes the following steps:

[0006] Step 1: Before assembling the extraction ring cavity A with the two red collar rings, perform a dimensional check;

[0007] Before assembling the extraction ring cavity A and the red ring assembly, use an outside micrometer to measure the thickness of the mating position and verify the parallelism of the individual parts.

[0008] Step 2: Simulated assembly inspection;

[0009] Stack the No. 5 red collar, the extraction ring cavity, and the No. 6 red collar in sequence from top to bottom, and conduct a simulated assembly inspection to check the clearance of the mating surfaces, ensuring that a 0.03mm feeler gauge cannot be inserted.

[0010] Step 3: Set of #5 red rings;

[0011] Heat the #5 red collar until it expands to a certain diameter (by increasing the inner diameter of the collar by 3.5mm), then fit it onto the corresponding position in the high-pressure inner cylinder and allow it to cool naturally to room temperature.

[0012] Step 4: Assembly of the extraction ring chamber and the #6 red collar;

[0013] Step 41: After heating the extraction ring cavity and the No. 6 red sleeve ring, install them sequentially onto the high-pressure inner cylinder;

[0014] Step 42: After installing the #6 red collar, while there is still a gap between the #6 red collar and the high-pressure inner cylinder in the diameter direction, quickly install six set screw tools on the outer circumferential side of the high-pressure inner cylinder, and tighten the set screw tools with a torque wrench to make the end faces of the extraction ring cavity zero gap with the end faces of the red collar, while also making the extraction ring cavity have a certain amount of pre-compression. At this point, the axial gap between the extraction ring cavity of the red collar inner cylinder is controlled.

[0015] Furthermore, in step one, the dimensional inspection procedure before assembling the red collar is as follows:

[0016] Step 11: Place the red ring horizontally with the contact surface between the red ring and the extraction ring cavity facing upwards;

[0017] Steps 1 and 2: Divide the upper surface of the red ring into 8 equal measurement points along its circumference in the opposite direction. In a clockwise direction, these are measurement position 1, measurement position 2, measurement position 3, measurement position 4, measurement position 5, measurement position 6, measurement position 7, and measurement position 8.

[0018] Step 13: Use an outside micrometer to measure the thickness of the mating positions at the 8 measuring points in Step 12, and determine whether they meet the assembly requirements.

[0019] Furthermore, the set screw tool in step four-two includes an L-shaped connecting plate and a set screw. Two threaded holes are opened on one plane of the L-shaped connecting plate and are installed on the high-pressure inner cylinder by bolts. A set screw hole is opened on the other plane of the L-shaped connecting plate. The set screw is installed on the set screw hole and the end of the set screw is pressed against the end face of the No. 6 red collar.

[0020] Furthermore, in step four two, the six set screw tools are evenly distributed on the high-pressure inner cylinder in the circumferential direction.

[0021] Furthermore, in step four two, the tightening torques of the six set screw tools, with the longitudinal section of the high-pressure inner cylinder as the cutting plane, are as follows:

[0022] The tightening torque of the left-hand set screw tool is 1800 N·m;

[0023] The tightening torque of the right 2 set screw tool is 1800 N·m;

[0024] The tightening torque of the top left three set screw tool is 1300 N·m;

[0025] The tightening torque of the four set screws in the upper right corner is 1300 N·m;

[0026] The tightening torque of the bottom left 5 set screw tool is 1300 N·m;

[0027] The tightening torque of the bottom right 6 set screw tool is 1800 N·m.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. This invention optimizes the existing assembly process for the extraction ring cavity and the red collar ring. Through theoretical calculations and multiple experimental verifications, the relationship between the tightening torque of the set screw tool and the axial clearance of the extraction ring cavity after cooling is determined. The tightening force of the set screw is parameterized to ensure that the axial clearance of the extraction ring cavity and the red collar ring is within acceptable limits after installation. The feasibility of this solution was verified during assembly at the Gansu Electric Power Investment Changle Project, resulting in an axial clearance control scheme for the extraction ring cavity of this novel structure, providing technical support for the installation of similar units in the company's future projects.

[0030] 2. After assembly, the axial clearance between the extraction ring cavity and the sleeve ring was measured to be 0.03 mm, and a feeler gauge could not be inserted, meeting the design requirements. This invention provides a solution for controlling the axial clearance of the extraction ring cavity, ensuring product quality and avoiding quality problems such as steam leakage and ring cavity damage caused by improper installation. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 This is a schematic diagram of a single-piece measurement of the red collar;

[0033] Figure 3 This is a schematic diagram simulating assembly inspection;

[0034] Figure 4 This is a schematic diagram of the structure of set screw C;

[0035] Figure 5 This is a diagram showing the installation positions of the six set screw tools. Detailed Implementation

[0036] Specific implementation method one: Combining Figures 1 to 5 This embodiment describes a method for controlling the axial clearance between the extraction ring cavities of the inner cylinder of a red-sleeved cylinder, which includes the following steps:

[0037] Step 1: Before assembling the extraction ring cavity A with the two red collar rings, perform a dimensional check;

[0038] Before assembling the extraction ring cavity A and the red ring assembly, use an outside micrometer to measure the thickness of the mating position and verify the parallelism of the individual parts.

[0039] Step 2: Simulated assembly inspection;

[0040] Stack the No. 5 red collar, extraction ring cavity A, and No. 6 red collar in sequence from top to bottom, and conduct a simulated assembly inspection to check the clearance of the mating surfaces, ensuring that a 0.03mm feeler gauge cannot be inserted.

[0041] Step 3: Set of #5 red rings;

[0042] Heat the #5 red collar until it expands to a certain diameter (meaning the inner diameter of the collar increases by 3.5mm), then fit it onto the corresponding position in the high-pressure inner cylinder and allow it to cool naturally to room temperature.

[0043] Step 4: Assembly of extraction ring chamber A and #6 red collar;

[0044] Step 41: After heating the extraction ring cavity A and the No. 6 red ring, install them sequentially onto the high-pressure inner cylinder;

[0045] Step 42: After installing the #6 red collar, while there is still a gap between the #6 red collar and the high-pressure inner cylinder in the diameter direction, quickly install 6 set screw tools on the outer circumferential side of the high-pressure inner cylinder, and tighten the set screw tools with a torque wrench to make the end faces of the two ends of the extraction ring cavity A and the end faces of the red collar zero gap, while making the extraction ring cavity A have a certain amount of pre-compression. Thus, the axial gap between the extraction ring cavities of the red collar inner cylinder is controlled.

[0046] This implementation method ensures accuracy during installation by inspecting the workpiece before installation. This avoids problems such as installation failure due to insufficient pre-inspection, which could lead to heat treatment failures after installation. Consequently, it saves assembly costs and improves assembly efficiency.

[0047] In this embodiment, when addressing the issue of zero clearance between the two end faces of the extraction annular cavity A and the end face of the red ring in the present invention, not only was the thermal expansion and contraction of the red ring considered, but also the parameters for applying preload to the red ring were taken into account, thereby truly ensuring the realization of zero clearance. This improves assembly precision and ensures the safe and reliable operation of the entire turbine unit.

[0048] Specific Implementation Method Two: Combining Figure 2 This embodiment describes the following step in which a dimensional check is performed before assembling the red collar:

[0049] Step 11: Place the red ring horizontally, with the contact surface between the red ring and the extraction ring cavity A facing upwards;

[0050] Steps 1 and 2: Divide the upper surface of the red ring into 8 equal measurement points along its circumference in the opposite direction. In a clockwise direction, these are measurement position 1, measurement position 2, measurement position 3, measurement position 4, measurement position 5, measurement position 6, measurement position 7, and measurement position 8.

[0051] Step 13: Use an outside micrometer to measure the thickness of the mating positions at the 8 measuring points in Step 12, and determine whether they meet the assembly requirements.

[0052] This design facilitates the inspection of the structural dimensions of the red collar before assembly, ensuring assembly requirements are met. Other components and connections are the same as in Specific Implementation Method One.

[0053] Specific implementation method three: Combining Figure 5 In this embodiment, the set screw tool in step four-two includes an L-shaped connecting plate B and a set screw C. Two threaded holes are opened on one plane of the L-shaped connecting plate B and it is installed on the high-pressure inner cylinder by bolts. A set screw hole is opened on the other plane of the L-shaped connecting plate B. The set screw C is installed on the set screw hole and the end of the set screw C is pressed against the end face of the 6# red collar.

[0054] This design is simple in structure, easy to install quickly on the high-pressure inner cylinder, and can apply a certain preload to the red collar immediately. Other components and connections are the same as in specific implementation method one or two.

[0055] Specific implementation method four: Combination Figure 5 In this embodiment, the six set screw tools in step four-two are evenly distributed circumferentially on the high-pressure inner cylinder. This arrangement facilitates the even distribution of points for applying preload to the red collar. Other components and connections are the same as in specific embodiments one, two, or three.

[0056] Specific Implementation Method Five: Combining Figure 5 In this embodiment, the six set screw tools in step four-two are cut along the longitudinal section of the high-pressure inner cylinder. The tightening torques of set screw C are as follows:

[0057] The tightening torque of the left-hand set screw tool is 1800 N·m;

[0058] The tightening torque of the right 2 set screw tool is 1800 N·m;

[0059] The tightening torque of the top left three set screw tool is 1300 N·m;

[0060] The tightening torque of the four set screws in the upper right corner is 1300 N·m;

[0061] The tightening torque of the bottom left 5 set screw tool is 1300 N·m;

[0062] The tightening torque of the bottom right 6 set screw tool is 1800 N·m.

[0063] This configuration allows for qualitative and precise measurement of the preload applied to the red collar, ensuring that the dimensions of the entire high-pressure inner cylinder meet design requirements after assembly. Other components and connections are the same as in specific implementation methods one, two, three, or four.

[0064] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make other changes within the spirit of the invention and apply it to fields not mentioned in the invention. Of course, all such changes made in accordance with the spirit of the invention should be included within the scope of protection claimed by the invention.

Claims

1. A method for controlling the axial clearance between the extraction ring cavities of the inner cylinder of a red sleeve, characterized in that: It includes the following steps: Step 1: Before assembling the extraction ring cavity (A) with the two red collar rings, perform a dimensional inspection; Before installing the extraction ring cavity (A) and the red ring assembly, use an outside micrometer to measure the thickness of the mating position and verify the parallelism of the individual parts. Step 2: Simulated assembly inspection; Stack the No. 5 red collar, the extraction ring cavity (A), and the No. 6 red collar in sequence from top to bottom, and conduct a simulated assembly inspection to check the clearance of the mating surfaces and ensure that a 0.03mm feeler gauge cannot be inserted. Step 3: Set of #5 red rings; Heat the No. 5 red collar. When the No. 5 red collar expands to a certain diameter, fit it into the corresponding position in the high-pressure inner cylinder and let it cool naturally to room temperature. Step 4: Assembly of the extraction ring chamber (A) and the #6 red collar; Step 41: After heating the extraction ring cavity (A) and the No. 6 red ring, install them sequentially onto the high-pressure inner cylinder; Step 42: After the installation of the No. 6 red collar, while there is still a gap between the No. 6 red collar and the high-pressure inner cylinder in the diameter direction, quickly install 6 set screw tools on the outer circumferential side of the high-pressure inner cylinder, and tighten the set screw tools with a torque wrench to make the end faces of the extraction ring cavity (A) and the end faces of the red collar zero gap, and at the same time make the extraction ring cavity (A) have a certain amount of pre-compression. Thus, the axial gap between the extraction ring cavities of the red collar inner cylinder is controlled. The set screw tool in step 42 includes an L-shaped connecting plate (B) and a set screw (C). Two threaded holes are opened on one plane of the L-shaped connecting plate (B), and it is installed on the high-pressure inner cylinder by bolts. A set screw hole is opened on the other plane of the L-shaped connecting plate (B). The set screw (C) is installed on the set screw hole, and the end of the set screw (C) is pressed against the end face of the 6# red collar.

2. The method for controlling the axial clearance between the extraction ring cavities of the inner cylinder of the red sleeve according to claim 1, characterized in that: In step one, the dimensional inspection steps before assembling the red collar are as follows: Step 11: Place the red ring horizontally with the contact surface between the red ring and the extraction ring cavity (A) facing upwards; Steps 1 and 2: Divide the upper surface of the red ring into 8 equal measurement points along its circumference in the opposite direction. In a clockwise direction, these are measurement position 1, measurement position 2, measurement position 3, measurement position 4, measurement position 5, measurement position 6, measurement position 7, and measurement position 8. Step 13: Use an outside micrometer to measure the thickness of the mating positions at the 8 measuring points in Step 12, and determine whether they meet the assembly requirements.

3. The method for controlling the axial clearance between the extraction ring cavities of the inner cylinder of the red sleeve according to claim 1, characterized in that: In step four, the six set screw tools are evenly distributed on the high-pressure inner cylinder in a circumferential direction.

4. The method for controlling the axial clearance between the extraction ring cavities of the inner cylinder of the red sleeve according to claim 1, characterized in that: In step four, the six set screw tools are cut along the longitudinal section of the high-pressure inner cylinder. The tightening torques of set screw C are as follows: The tightening torque of the left-hand set screw tool is 1800 N·m; The tightening torque of the right 2 set screw tool is 1800 N·m; The tightening torque of the top left three set screw tool is 1300 N·m; The tightening torque of the four set screws in the upper right corner is 1300 N·m; The tightening torque of the bottom left 5 set screw tool is 1300 N·m; The tightening torque of the bottom right 6 set screw tool is 1800 N·m.

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