A method for repairing armored thermocouple for measuring temperature of steam turbine cylinder of thermal power unit

Abstract

The invention discloses a method for repairing an armored thermocouple for measuring the temperature of a steam turbine cylinder of a thermal power unit, which relates to the technical field of steam turbine maintenance, and includes the following steps: cleaning the exposed thermocouple wire; grinding the surface of the thermocouple wire with 300 to 500 mesh sandpaper; dispersing the ground thermocouple wire; coating the thermocouple wire; wrapping and fixing the thermocouple wire after coating with a glass ribbon; and covering the repaired part with a thin aluminum plate until the thermocouple wire works normally. Compared with the traditional replacement and repair of armored thermocouples, the invention is simple to operate and low in cost, and can realize online rapid recovery of the insulation and resistance of the thermocouple after the explosion, so that the damaged armored thermocouple can be used normally again, which greatly reduces the cost of thermocouple repair; while brushing, the mixed liquid can be crushed and stirred, which avoids the waste of the mixed liquid while ensuring the uniformity and stability, and greatly improves the utilization efficiency of the mixed liquid.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbine maintenance, in particular to a method for repairing an armored thermocouple for measuring the temperature of a steam turbine cylinder of a thermal power unit. Background Art

[0002] Armored thermocouples are commonly used in industrial temperature measuring elements. They are made of thermocouple conductors, high-insulation magnesium oxide fillings, and outer stainless steel protective tubes. They have the advantages of being able to bend, resistant to high pressure, fast thermal response time, good corrosion resistance, good high-temperature creep strength, and durability. At present, the thermocouples used to measure the temperature of the turbine cylinder of thermal power generating units are basically armored thermocouples made of stainless steel protective tubes. However, in actual applications, it is found that under certain circumstances, the stainless steel protective tube (armor) of this type of armored thermocouple will corrode, causing the thermocouple wire to short-circuit, and thus become unusable.

[0003] Since armored thermocouples are basically installed inside high-temperature mechanical equipment, when repairing and replacing armored thermocouples, it is currently necessary to dismantle the equipment's external protective cover, external insulation, fixing facilities, etc. to reach the installation position of the thermocouple and dismantle and replace it. The workload is very large and the cost is high, which has an extremely adverse impact on the operation of thermal power units and the control of production costs. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit comprises the following steps:

[0007] Clean exposed thermocouple wires;

[0008] Use 300 to 500 grit sandpaper to sand the surface of the thermocouple wire;

[0009] Disperse the polished thermocouple wires;

[0010] Fill and coat the thermocouple wire;

[0011] Use glass ribbon to wrap and fix the thermocouple wire after the coating treatment;

[0012] Use a thin aluminum sheet to cover the repaired area until the thermocouple wire functions properly.

[0013] Preferably, the cleaning of the exposed thermocouple wire comprises the following steps:

[0014] Cut off the burst thermocouple armor;

[0015] Stripping of magnesium oxide deposits from thermocouple wires;

[0016] Separate the shorted thermocouple wires.

[0017] Preferably, the step of coating the thermocouple wire comprises the following steps:

[0018] A mixture of high temperature resistant insulation and corrosion resistant coating and curing agent is prepared by stirring in a ratio of 9:1;

[0019] Let the prepared mixture stand for 5 minutes;

[0020] Use a coating device to brush the surface and gaps of the thermocouple wire;

[0021] Use a protective cover to cover the painted thermocouple wire area for 24 hours;

[0022] Use the coating device to repeatedly coat the surface and gaps of the thermocouple wire;

[0023] Use an megohmmeter to remotely measure the working parameters of the dried thermocouple wire.

[0024] Preferably, the coating device comprises a bracket, a non-slip handle is fixedly installed at the middle of the top of the bracket, a second transmission connecting rod is fixedly installed between the two ends of the inner side wall of the bracket, a fourth transmission gear is fixedly installed on the outer wall of the second transmission connecting rod, a first transmission connecting rod is rotatably connected between the two ends of the inner side wall of the bracket through a bearing, a coating roller and a first transmission gear are fixedly installed on the outer wall of the first transmission connecting rod, a filling cavity is also fixedly installed on the inner side wall of one side of the bracket, a dust cover is fixedly installed on the side of the filling cavity, and the inner side wall of the filling cavity is also movable to limit the sleeve A limit bearing is provided, on which a second transmission gear is fixedly connected, the second transmission connecting rod passes through the center of the limit bearing, and a bearing is provided at the contact portion between the limit bearing and the second transmission connecting rod, the interior of the limit bearing is also rotatably connected to a plurality of third transmission connecting rods distributed around the second transmission connecting rod through bearings, the outer side wall of one end of the second transmission connecting rod extending to the inner side of the stuffing chamber is movably sleeved with a driving frame, the third transmission connecting rod passes through the driving frame, and a bearing is also provided at the contact portion between the third transmission connecting rod and the driving frame.

[0025] Preferably, the top end of the driving frame is designed to be arc-shaped to match the inner side wall of the filling cavity, and the top end of the driving frame fits the inner side wall of the filling cavity.

[0026] Preferably, an inner gear ring is provided on the inner side wall of the second transmission gear, and a third transmission gear is fixedly installed on one end of the third transmission connecting rod extending to the inner side of the second transmission gear, the first transmission gear is meshed with the outer teeth of the second transmission gear, the inner gear ring of the second transmission gear is meshed with the third transmission gear, and the third transmission gear is meshed with the fourth transmission gear.

[0027] Preferably, one end of the driving frame fits with the inner wall of the filling cavity, the other end of the driving frame contacts with the outer wall of the second transmission connecting rod, and the middle part of the driving frame where the third transmission connecting rod is designed is hollowed out.

[0028] Preferably, stirring blades are fixedly mounted on the outer side wall of the third transmission connecting rod, and the number of stirring blades mounted on the outer side wall of each group of the third transmission connecting rods is different.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. Compared with the traditional replacement and repair of armored thermocouples, the present invention is simple to operate and low in cost. It can quickly restore the insulation and resistance of the thermocouple after the explosion online, so that the damaged armored thermocouple can be used normally again, which greatly reduces the cost of thermocouple repair.

[0031] 2. Through multiple sets of stirring blades with different numbers of blades, the lumps and sediments in the mixed liquid can be efficiently broken and stirred while the coating roller is brushing, which can effectively maintain the fluidity and miscibility of the mixed liquid, prevent the mixed liquid from precipitating, avoid the waste of the mixed liquid, ensure the uniformity and stability, and greatly improve the utilization efficiency of the mixed liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit proposed by the present invention;

[0033] Figure 2 A schematic diagram of a method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit proposed by the present invention;

[0034] Figure 3 A schematic diagram of a method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit proposed by the present invention;

[0035] Figure 4 The overall structural schematic diagram of a coating device for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit proposed by the present invention;

[0036] Figure 5A schematic diagram of the internal structure of a coating device for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit proposed by the present invention;

[0037] Figure 6 A schematic diagram of the internal structure of a coating device for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit proposed by the present invention;

[0038] Figure 7 A schematic diagram of the internal structure of a coating device for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit proposed by the present invention;

[0039] Figure 8 The present invention is a schematic diagram of the internal structure of a coating device for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit.

[0040] In the figure: 1. bracket; 2. anti-slip handle; 3. dust cover; 4. stuffing chamber; 5. coating roller; 6. first transmission connecting rod; 7. first transmission gear; 8. limit bearing; 9. second transmission gear; 10. third transmission gear; 11. second transmission connecting rod; 12. fourth transmission gear; 13. third transmission connecting rod; 14. driving frame; 15. stirring blade. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0042] Reference Figure 1-3 A method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit comprises the following steps:

[0043] S1: Clean the exposed thermocouple wire;

[0044] S2: Use 300 to 500 grit sandpaper to sand the surface of the thermocouple wire;

[0045] S3: Disperse the polished thermocouple wires;

[0046] S4: Fill and coat the thermocouple wire;

[0047] S5: Use glass ribbon to wrap and fix the thermocouple wire after the coating treatment;

[0048] S6: Use a thin aluminum plate to cover the repaired part until the thermocouple wire works normally;

[0049] Specifically, when polishing the surface of the thermocouple wire, it is necessary to polish the surface of the thermocouple wire until the metallic luster is exposed. This operation is used to further clean the oxide layer, metal impurities and attachments on the surface of the thermocouple wire, thereby improving the adhesion of the surface of the thermocouple wire;

[0050] When dispersing thermocouple wires, it is necessary to keep the wire cores insulated from each other, and to place the thermocouple wires in a suitable position so that the thermocouple wires are insulated from the ground at the same time.

[0051] like Figure 2 , cleaning exposed thermocouple wire includes the following steps:

[0052] S101: Cut off the exploded thermocouple armor;

[0053] S102: Stripping magnesium oxide attached to the thermocouple wire;

[0054] S103: Separate the short-circuited thermocouple wire.

[0055] like Figure 3 , the filling and coating of thermocouple wire includes the following steps:

[0056] S201: Mix the high temperature resistant insulation and corrosion resistant coating and curing agent in a ratio of 9:1;

[0057] S202: Let the prepared mixed solution stand for 5 minutes;

[0058] S203: Use a coating device to brush the surface and gaps of the thermocouple wire;

[0059] S204: Use a protective cover to cover the painted thermocouple wire area for 24 hours;

[0060] S205: Use a coating device to repeatedly coat the surface and gaps of the thermocouple wire;

[0061] S206: Use a megohmmeter to remotely measure the working parameters of the thermocouple wire after drying;

[0062] Specifically, the high temperature resistant insulating and corrosion resistant coating adopts high temperature resistant ceramic insulating coating;

[0063] The insulation coefficient of the thermocouple wire is remotely measured by the megohmmeter. When the insulation coefficient of the thermocouple wire meets the normal working parameters, the repair of the thermocouple wire basically meets the normal working requirements, that is, the repair work of the armored thermocouple is completed.

[0064] like Figure 4-8The coating device includes a bracket 1, a non-slip handle 2 is fixedly installed at the middle of the top of the bracket 1, a second transmission connecting rod 11 is fixedly installed between the two ends of the inner wall of the bracket 1, and a fourth transmission gear 12 is fixedly installed on the outer wall of the second transmission connecting rod 11. A first transmission connecting rod 6 is rotatably connected between the two ends of the inner wall of the bracket 1 through a bearing, and a coating roller 5 and a first transmission gear 7 are fixedly installed on the outer wall of the first transmission connecting rod 6. A packing cavity 4 is also fixedly installed on the inner wall of one side of the bracket 1, and a dust cover 3 is fixedly installed on the side of the packing cavity 4. The inner wall of the packing cavity 4 is also movably limited by a sleeve A limit bearing 8 is fixedly connected to the limit bearing 8 with a second transmission gear 9, a second transmission connecting rod 11 passes through the center of the limit bearing 8, and a bearing is provided at the contact portion between the limit bearing 8 and the second transmission connecting rod 11. The interior of the limit bearing 8 is also rotatably connected through bearings to multiple groups of third transmission connecting rods 13 distributed around the second transmission connecting rod 11, the second transmission connecting rod 11 extends to one end of the inner side of the filling chamber 4 and a driving frame 14 is movably sleeved on the outer wall, the third transmission connecting rod 13 passes through the driving frame 14, and a bearing is also provided at the contact portion between the third transmission connecting rod 13 and the driving frame 14.

[0065] like Figure 8 The top end of the driving frame 14 is designed to be arc-shaped to match the inner wall of the filling cavity 4 , and the top end of the driving frame 14 fits the inner wall of the filling cavity 4 .

[0066] like Figure 5 An inner gear ring is provided on the inner wall of the second transmission gear 9, and a third transmission gear 10 is fixedly installed on one end of the third transmission connecting rod 13 extending to the inner side of the second transmission gear 9, the first transmission gear 7 is meshed with the outer teeth of the second transmission gear 9, the inner gear ring of the second transmission gear 9 is meshed with the third transmission gear 10, and the third transmission gear 10 is meshed with the fourth transmission gear 12.

[0067] like Figure 8 One end of the driving frame 14 is in contact with the inner wall of the filling chamber 4, and the other end of the driving frame 14 is in contact with the outer wall of the second transmission connecting rod 11. The middle part of the driving frame 14 where the third transmission connecting rod 13 is designed is hollowed out.

[0068] like Figure 8 , the outer wall of the third transmission connecting rod 13 is fixedly mounted with stirring blades 15, and the number of blades of the stirring blades 15 mounted on the outer wall of each group of the third transmission connecting rod 13 is different;

[0069] Specifically, the stirring blade 15 with fewer blades can have an efficient crushing and mixing effect on large particle precipitation or lumps in the mixed liquid, while the stirring blade 15 with more blades can have a better mixing and crushing effect on small particle lumps and precipitation in the mixed liquid than the stirring blade 15 with fewer blades. Through multiple groups of stirring blades 15 with different numbers of blades, the lumps and precipitation in the mixed liquid can be efficiently crushed and mixed during the circulation process, and the mixed liquid can be fully stirred, thereby ensuring the working efficiency of the mixed liquid.

[0070] In the present invention, when the coating device is used to brush the thermocouple wire, the thermocouple wire is first placed on the protective pad, and then the prepared solution is poured into the inner cavity of the filling cavity 4 through the opening at the top of the filling cavity 4, and the non-slip handle 2 is further held, and the bottom of the coating roller 5 is attached to the place where the thermocouple wire needs to be brushed, and the coating roller 5 is further pulled by the non-slip handle 2 to move along the surface of the thermocouple wire. Through the rotation of the coating roller 5, the mixed liquid inside the filling cavity 4 is driven to adhere to the surface of the coating roller 5 through the opening at the bottom of the filling cavity 4. Then, the surface and gaps of the thermocouple wire are evenly coated by rotating the coating roller 5; at the same time, the first transmission gear 7 is driven to rotate by the rotation of the coating roller 5, and then the second transmission gear 9 and the limit bearing 8 are driven to rotate, and the limit bearing 8 drives the drive frame 14 to rotate around the second transmission connecting rod 11, and at the same time, the third transmission connecting rod 13 rotates around the second transmission connecting rod 11, and the third transmission gear 9 is driven to rotate around the third transmission gear 10 through the meshing of the second transmission gear 9 and the third transmission gear 10, and the meshing of the third transmission gear 10 and the fourth transmission gear 12. 10 rotates around the fourth transmission gear 12 while the third transmission gear 10 also keeps rotating, that is, driving the stirring blades 15 to rotate, and the mixed liquid attached to the inner wall of the filling chamber 4 is scraped by the rotation of the driving frame 14 to prevent the mixed liquid from adhering to the inner wall of the filling chamber 4. At the same time, with the rotation of the driving frame 14 and the stirring blades 15, the mixed liquid in the inner cavity of the filling chamber 4 can be stirred. At the same time, the number of blades of each group of stirring blades 15 is different. Among them, the stirring blades 15 with fewer blades can have an efficient crushing and mixing effect on large particle precipitation or agglomeration in the mixed liquid, and the stirring blades 15 with more blades can have a better mixing and crushing effect on small particle agglomeration and precipitation in the mixed liquid than the stirring blades 15 with fewer blades. Through multiple groups of stirring blades 15 with different numbers of blades, the agglomeration and precipitation in the mixed liquid can be efficiently crushed and mixed, the fluidity and miscibility of the mixed liquid can be effectively maintained, the mixed liquid can be prevented from precipitation, and the waste of the mixed liquid is avoided while ensuring the working state of the mixed liquid and the utilization efficiency of the mixed liquid.

[0071] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit, characterized in that: The following steps are involved: Clean exposed thermocouple wires; Use 300 to 500 grit sandpaper to sand the surface of the thermocouple wire; Disperse the polished thermocouple wires; Fill and coat the thermocouple wire; Use glass ribbon to wrap and fix the thermocouple wire after the coating treatment; Use a thin aluminum plate to cover the repaired area until the thermocouple wire works normally; The method of coating the thermocouple wire comprises the following steps: A mixture of high temperature resistant insulation and corrosion resistant coating and curing agent is prepared by stirring in a ratio of 9:1; Let the prepared mixture stand for 5 minutes; Use a coating device to brush the surface and gaps of the thermocouple wire; Use a protective cover to cover the painted thermocouple wire area for 24 hours; Use the coating device to repeatedly coat the surface and gaps of the thermocouple wire; Use a megohmmeter to remotely measure the working parameters of the thermocouple wire after drying; The coating device comprises a bracket (1), a non-slip handle (2) is fixedly mounted at the middle of the top of the bracket (1), a second transmission connecting rod (11) is fixedly mounted between the two ends of the inner wall of the bracket (1), a fourth transmission gear (12) is fixedly mounted on the outer wall of the second transmission connecting rod (11), a first transmission connecting rod (6) is rotatably connected between the two ends of the inner wall of the bracket (1) via a bearing, a coating roller (5) and a first transmission gear (7) are fixedly mounted on the outer wall of the first transmission connecting rod (6), a packing cavity (4) is also fixedly mounted on one side of the inner wall of the bracket (1), a dust cover (3) is fixedly mounted on the side of the packing cavity (4), and the inner wall of the packing cavity (4) is also movable with a limit sleeve connected to a limit bearing. (8), a second transmission gear (9) is fixedly connected to the limit bearing (8), the second transmission connecting rod (11) passes through the center of the limit bearing (8), and a bearing is provided at the contact portion between the limit bearing (8) and the second transmission connecting rod (11), the interior of the limit bearing (8) is also rotatably connected to a plurality of third transmission connecting rods (13) distributed around the second transmission connecting rod (11) through bearings, the outer wall of one end of the second transmission connecting rod (11) extending to the inner side of the stuffing chamber (4) is movably sleeved with a driving frame (14), the third transmission connecting rod (13) passes through the driving frame (14), and a bearing is also provided at the contact portion between the third transmission connecting rod (13) and the driving frame (14).

2. The method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit according to claim 1, characterized in that: The cleaning of the exposed thermocouple wire comprises the following steps: Cut off the burst thermocouple armor; Stripping of magnesium oxide deposits from thermocouple wires; Separate the shorted thermocouple wires.

3. The method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit according to claim 1, characterized in that: The top end of the driving frame (14) is designed to be arc-shaped and matches the inner side wall of the filling cavity (4), and the top end of the driving frame (14) fits the inner side wall of the filling cavity (4).

4. The method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit according to claim 1, characterized in that: The inner side wall of the second transmission gear (9) is provided with an inner gear ring, the third transmission connecting rod (13) extends to one end inside the second transmission gear (9) and is fixedly mounted with a third transmission gear (10), the first transmission gear (7) is meshed with the outer teeth of the second transmission gear (9), the inner gear ring of the second transmission gear (9) is meshed with the third transmission gear (10), and the third transmission gear (10) is meshed with the fourth transmission gear (12).

5. The method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit according to claim 1, characterized in that: One end of the driving frame (14) is in contact with the inner wall of the filling cavity (4), and the other end of the driving frame (14) is in contact with the outer wall of the second transmission connecting rod (11). The middle portion of the driving frame (14) where the third transmission connecting rod (13) is located is hollowed out.

6. The method for repairing an armored thermocouple for measuring temperature of a steam turbine cylinder of a thermal power unit according to claim 1, characterized in that: The outer wall of the third transmission connecting rod (13) is fixedly mounted with stirring blades (15), and the number of stirring blades (15) mounted on the outer wall of each group of the third transmission connecting rod (13) is different.

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