A device and method for repairing insulation of a heating tube of a voltage stabilizer electric heater in a nuclear power plant

Abstract

The present invention relates to the field of electrical equipment maintenance, and more specifically to a device and method for repairing the insulation of a heating tube of an electric heater in a nuclear power plant voltage regulator. The device comprises an upper assembly, a control module, a lower assembly, a fan motor, a heat-insulating fixing plate, a heat-insulating outer wall, fan blades, a heating liner, and a fixing bracket. The upper assembly is connected to the lower assembly, the control module is connected to the top of the upper assembly, the upper assembly comprises the fan motor, the heat-insulating fixing plate, the heat-insulating outer wall, and the fan blades, the heat-insulating fixing plate is connected to the top of the heat-insulating outer wall, the fan motor is connected to the bottom surface of the heat-insulating fixing plate, and the fan blades are connected to the bottom of the fan motor. The lower assembly comprises a heating liner and a fixing bracket, the heating liner being connected to the fixing bracket. The present invention can repair the insulation of the heating tube of the voltage regulator electric heater, improve the performance of the heater, ensure the normal operation of the voltage regulator, and at the same time reduce maintenance costs and increase the operational reliability of the nuclear power plant.

Description

Technical Field

[0001] The present invention relates to the field of electrical equipment maintenance, and in particular to a device and method for repairing the insulation of a heating tube of a voltage stabilizer electric heater in a nuclear power plant. Background Art

[0002] The pressurizer is a crucial component of the primary circuit system in a nuclear power plant. A pressurizer with an electric heater assembly, as part of the pressure stabilization system, is responsible for establishing primary circuit pressure during heating conditions, maintaining pressure during steady-state conditions, limiting pressure deviations during transient conditions, and cooling the pressurizer at a set rate during reactor cooldown. The pressurizer heating and pressure establishment are achieved by the pressurizer's electric heater. Therefore, the operating status of the pressurizer heater directly affects pressurizer performance and primary circuit conditions. Currently, the ends of the heater tubes in common pressurizer heaters in China are filled with insulating material to ensure proper insulation. Due to the high temperatures and radioactivity within the nuclear island, the insulation material at the ends of the pressurizer heater tubes can crack or deteriorate, reducing heater performance and affecting pressurizer functionality. In severe cases, this can lead to pressurizer unavailability and unit shutdown. When insulation degradation is detected at the ends of pressurizer heater tubes, the current maintenance strategy is typically to replace the entire unit, which results in long manufacturing cycles and high repair costs.

[0003] Therefore, it is necessary to provide a device and method for repairing the insulation of the heating tube of the electric heater of the nuclear power plant stabilizer to solve the shortcomings of the existing technology. Summary of the Invention

[0004] The purpose of the present invention is to provide a device and method for repairing the insulation of the heating tube of the electric heater of the nuclear power plant stabilizer, which can repair the insulation of the heating tube of the electric heater of the stabilizer, improve the performance of the heater, ensure the normal operation of the stabilizer, and at the same time reduce maintenance costs and increase the operational reliability of the nuclear power plant.

[0005] The technical solution for achieving the purpose of the present invention is as follows:

[0006] A device for repairing insulation of a heating tube of a voltage stabilizer electric heater in a nuclear power plant, comprising an upper assembly, a control module, a lower assembly, a fan motor, a heat-insulating fixing plate, a heat-insulating outer wall, fan blades, a heating liner, and a fixing bracket;

[0007] Among them, the upper component is connected to the lower component, the control module is connected to the top of the upper component, the upper component includes a fan motor, an insulation fixing plate, an insulation outer wall and fan blades, the insulation fixing plate is connected to the top of the insulation outer wall, the fan motor is connected to the bottom surface of the insulation fixing plate, and the fan blades are connected to the lower part of the fan motor; the lower component includes a heating liner and a fixed bracket, and the heating liner is connected to the fixed bracket.

[0008] The bottom of the heat-insulating outer wall is fixed to the upper flange by welding.

[0009] The bottom of the heating liner is fixed to the fixing bracket and the lower flange by welding.

[0010] A plurality of upper connecting holes are evenly arranged on the upper flange.

[0011] A plurality of lower connecting holes are evenly formed on the lower flange.

[0012] There are multiple fixing brackets.

[0013] The control module includes a temperature controller, a power switch, an air switch, a fuse, a contactor, a temperature measuring resistor, a contactor contact and an AC power supply, wherein the power switch is connected to a 380V AC power supply; the fuse is connected to the power switch and the contactor contact; the air switch is connected to a single phase of the power switch and a power neutral line; the fan motor is connected to the air switch; the I1 terminal of the temperature controller is connected to a single phase of a 380V AC power supply, the I2 terminal of the temperature controller is connected to a neutral line of a 380V AC power supply, the Out1 terminal of the temperature controller is connected to the A1 terminal of the contactor, and the Out2 terminal of the temperature controller is connected to the A2 terminal of the contactor; the temperature measuring resistor is connected to terminals P3, P2 and P1 of the temperature controller.

[0014] The repair method of the insulation repair device of the voltage stabilizer electric heater heating tube comprises the following steps:

[0015] Step 1: Connect the upper connection hole of the insulation repair device to the lower connection hole, and connect the fixing bracket to the installation spare hole of the heater flange with bolts 26 to fix the insulation repair device on the heater. At this time, all the electric heating tubes of the heater are located in the heating liner of the device;

[0016] Step 2: Connect the insulation repair device to a 380V AC power supply, close the power switch, and close the air switch. At this time, the temperature controller is energized, and the fan motor is powered on and starts working, and the air circulates internally in the insulation repair device; close the fuse, set the target temperature on the temperature controller to 80°C, and the heating time to 2 hours. At this time, because the temperature measured by the temperature measuring resistor is lower than 80°C, the temperature controller terminals Out1 and Out2 output 24V DC voltage, the contactor is energized, and the contactor contacts change from open to closed state. The heating tank starts to work, and the air temperature in the device gradually increases and stabilizes at 80°C; after heating for 2 hours, set the target temperature on the temperature controller to 100°C and the heating time to 2 hours; after heating for 2 hours, set the target temperature on the temperature controller to 150°C and continue heating for 1 hour;

[0017] Step 3: After heating is completed, disconnect the air switch, fuse, and power switch; remove the connecting bolts between the insulation repair device fixing bracket and the installation spare hole of the heater flange, and remove the insulation repair device.

[0018] The beneficial technical effects of the present invention are:

[0019] (1) The present invention provides a device and method for repairing the insulation of a heating tube of a voltage regulator electric heater in a nuclear power plant, which can repair the insulation of the end of the voltage regulator electric heater heating tube and improve the performance of the electric heater. The device and method repair the insulation of the end of the voltage regulator electric heater heating tube by refilling the insulating material and heating and baking the device, which has high reliability.

[0020] (2) The device and method for repairing the insulation of a heating tube of a voltage stabilizer in a nuclear power plant according to the present invention can reduce the maintenance cost caused by the need to replace the heater due to insulation degradation; at the same time, it can save the maintenance time caused by the need to replace the heater due to insulation degradation, thereby shortening the critical path time of the nuclear power plant unit overhaul;

[0021] (3) The device and method for repairing the insulation of the heating tube of the electric heater of a nuclear power plant voltage stabilizer of the present invention have low design and manufacturing costs, are easy to disassemble and assemble, and are convenient for maintenance;

[0022] (4) The present invention relates to a device and method for repairing insulation of a heating tube of a voltage stabilizer in a nuclear power plant. The device and method use a fan to generate internal air circulation, so that the material is heated evenly during insulation repair, thereby greatly improving the success rate of insulation repair.

[0023] (5) The heat insulation fixing plate and the heat insulation outer wall of the upper component of the nuclear power plant voltage stabilizer electric heater heating tube insulation repair device of the present invention are both made of heat insulation materials, which improves the heating performance of the device and the service life of various components;

[0024] (6) The device and method for repairing the insulation of a heating tube of a voltage stabilizer electric heater of a nuclear power plant of the present invention have a wide range of applications and can be used for voltage stabilizer electric heaters of other nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of an insulation repair device for a heating tube of a nuclear power plant voltage stabilizer electric heater provided by the present invention;

[0026] Figure 2 This is an electrical schematic diagram of a control module of an insulation repair device for a heating tube of a voltage stabilizer electric heater in a nuclear power plant provided by the present invention;

[0027] Figure 3 This is an assembly diagram of the insulation repair device for the electric heater of a nuclear power plant voltage regulator provided by the present invention;

[0028] In the figure: 1-upper component; 2-control module; 3-lower component; 4-fan motor; 5-thermal insulation fixing plate; 6-insulation outer wall; 7-upper flange; 8-upper connecting hole; 9-fan blade; 10-heating liner; 11-lower flange; 12-lower connecting hole; 13-fixing bracket; 14-temperature controller; 15-power switch; 16-air switch; 17-fuse; 18-contactor; 19-temperature measuring resistor; 20-contactor contact; 21-AC power supply; 22-electric heating tube; 23-insulation repair device; 24-heater flange; 25-spare installation hole; 26-connecting bolt. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments described in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, the present invention provides a nuclear power plant voltage stabilizer electric heater heating tube insulation repair device, the device includes an upper component 1, a control module 2, a lower component 3, a fan motor 4, a heat insulation fixing plate 5, a heat insulation outer wall 6, an upper flange 7, an upper connection hole 8, a fan blade 9, a heating liner 10, a lower flange 11, a lower connection hole 12, a fixing bracket 13, a temperature controller 14, a power switch 15, an air switch 16, a fuse 17, and a contactor 18

[0031] The upper component 1 is connected to the lower component 3 , and the control module 2 is connected to the top of the upper component 1 .

[0032] The upper assembly 1 includes a heat-insulating fixing plate 5 and a heat-insulating outer wall 6, wherein the heat-insulating fixing plate 5 is connected to the top of the heat-insulating outer wall 6;

[0033] The fan motor 4 is connected to the bottom surface of the heat insulation fixing plate 5; the fan blade 9 is connected to the lower part of the fan motor 4;

[0034] The bottom of the insulation outer wall 6 is welded to the upper flange 7; the upper flange 7 is provided with eight upper connection holes 8, each of which is 45° apart;

[0035] The lower component 3 includes a heating liner 10, a lower flange 11 and a fixing bracket 13. The heating liner 10 is connected to the lower flange 11, and the fixing bracket 13 is connected to the heating liner 10 and the lower flange 11.

[0036] There are 3 fixing brackets 13;

[0037] The heating liner 10 is connected to the lower flange 11. The lower flange 11 is provided with eight lower connection holes 12. The angles of the connection holes 12 are 45 degrees apart.

[0038] like Figure 2 As shown, the control module 2 includes a temperature controller 14, a power switch 15, an air switch 16, a fuse 17, a contactor 18, a temperature measuring resistor 19, a contactor contact 20 and an AC power supply 21, wherein the power switch 15 is connected to the 380V AC power supply 21; the fuse 17 is connected to the power switch 15 and the contactor contact 20; the air switch 16 is connected to the single phase of the power switch 15 and the power neutral line; the fan motor 4 is connected to the air switch 16; the I1 terminal of the temperature controller 14 is connected to the single phase of the 380V AC power supply 21, the I2 terminal of the temperature controller 14 is connected to the neutral line of the 380V AC power supply 21, the Out1 terminal of the temperature controller 14 is connected to the A1 terminal of the contactor 18, and the Out2 terminal of the temperature controller 14 is connected to the A2 terminal of the contactor 18; the temperature measuring resistor 19 is connected to the terminals P3, P2 and P1 of the temperature controller 14.

[0039] like Figure 3 As shown, the present invention also provides a method for repairing the insulation repair device of the electric heater heating tube of the nuclear power plant stabilizer, the method comprising the following steps:

[0040] Step 1: Connect the upper connection holes 8 and the lower connection holes 12 of the insulation repair device 23 with bolts one by one, and connect the fixing bracket 13 and the spare installation holes 25 of the heater flange 24 with bolts 26 to fix the insulation repair device 23 on the heater. At this time, all the electric heating tubes 22 of the heater are located in the heating liner 10 of the device;

[0041] Step 2, connect the insulation repair device 23 to the 380V AC power supply 21, close the power switch 15, close the air switch 16, at this time the temperature controller 14 is energized, and the fan motor 4 is energized to start working, the air is circulated in the device, so that the temperature in the device is uniform, which can prevent uneven heating of the end of the heating tube due to local overheating; close the fuse 17, set the target temperature on the temperature controller 14 to 80°C, and the heating time is 2h. At this time, because the temperature measured by the temperature measuring resistor 19 is lower than 80°C, the temperature controller 14 terminals Out1 and Out2 output 24V DC voltage, the contactor 18 is energized, and the contactor contact 20 changes from an open circuit to a closed state, the heating liner 10 starts to work, and the air temperature in the device gradually increases and stabilizes at 80°C; after heating for 2h, set the target temperature on the temperature controller 14 to 100°C and the heating time to 2h; after heating for 2h, set the target temperature on the temperature controller 14 to 150°C and continue heating for 1h;

[0042] Step 3: After heating is completed, disconnect the air switch 16, fuse 17 and power switch 15; remove the connecting bolts 26 between the device fixing bracket 13 and the installation spare hole 25 of the heater flange 24, and remove the stabilizer electric heating tube repair device 23.

[0043] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Any content not described in detail in the present invention may be adapted from existing technologies.

Claims

1. A method for repairing an insulation repair device for a voltage stabilizer electric heater heating tube, characterized in that: The method comprises the following steps: Step 1: Connect the upper connection hole (8) of the insulation repair device (23) to the lower connection hole (12), and connect the fixing bracket (13) to the installation spare hole (25) of the heater flange (24) with bolts 26 to fix the insulation repair device (23) on the heater. At this time, all the electric heating tubes (22) of the heater are located in the heating liner (10) of the device; Step 2: Connect the insulation repair device (23) to a 380V AC power supply (21), close the power switch (15), close the air switch (16), and then the temperature controller (14) is energized, and the fan motor (4) is energized to start working, and the air circulates in the insulation repair device (23); close the fuse (17), set the target temperature on the temperature controller (14) to 80°C, and the heating time is 2h. At this time, because the temperature measured by the temperature measuring resistor (19) is lower than 80°C, the temperature controller (14) terminals Out1 and Out2 output a 24V DC voltage, the contactor (18) is energized, and the contactor contact (20) changes from an open circuit to a closed state, the heating liner (10) starts working, and the air temperature in the device gradually increases and stabilizes at 80°C; after heating for 2h, set the target temperature on the temperature controller (14) to 100°C, and the heating time is 2h; after heating for 2h, set the target temperature on the temperature controller (14) to 150°C, and continue heating for 1h; Step 3: After heating is completed, disconnect the air switch (16), fuse (17) and power switch (15); remove the connecting bolts (26) between the fixing bracket (13) of the insulation repair device (23) and the mounting spare hole (25) of the heater flange (24), and remove the insulation repair device (23); The insulation repair device (23) comprises an upper component (1), a control module (2), a lower component (3), a fan motor (4), a heat-insulating fixing plate (5), a heat-insulating outer wall (6), fan blades (9), a heating liner (10) and a fixing bracket (13); The upper component (1) is connected to the lower component (3), the control module (2) is connected to the top of the upper component (1), the upper component (1) includes a fan motor (4), a heat-insulating fixing plate (5), a heat-insulating outer wall (6) and a fan blade (9), the heat-insulating fixing plate (5) is connected to the top of the heat-insulating outer wall (6), the fan motor (4) is connected to the bottom surface of the heat-insulating fixing plate (5), and the fan blade (9) is connected to the lower part of the fan motor (4); the lower component (3) includes a heating liner (10) and a fixing bracket (13), and the heating liner (10) is connected to the fixing bracket (13).

2. The method for repairing the insulation repair device of a voltage stabilizer electric heater according to claim 1, characterized in that: The bottom of the heat-insulating outer wall (6) is fixed to the upper flange (7) by welding.

3. The method for repairing the insulation repair device of a voltage stabilizer electric heater according to claim 2, characterized in that: The bottom of the heating liner (10) is fixed to the fixing bracket (13) and the lower flange (11) by welding.

4. The method for repairing the insulation repair device of a voltage stabilizer electric heater according to claim 3, characterized in that: A plurality of upper connection holes (8) are evenly formed on the upper flange (7).

5. The method for repairing the insulation repair device of a voltage stabilizer electric heater according to claim 4, characterized in that: The lower flange (11) is evenly provided with a plurality of lower connection holes (12).

6. The method for repairing the insulation repair device of a voltage stabilizer electric heater according to claim 5, characterized in that: There are multiple fixing brackets (13).

7. The method for repairing the insulation repair device of a voltage stabilizer electric heater heating tube according to claim 6, characterized in that: The control module (2) includes a temperature controller (14), a power switch (15), an air switch (16), a fuse (17), a contactor (18), a temperature measuring resistor (19), a contactor contact (20), and an AC power supply (21), wherein the power switch (15) is connected to a 380V AC power supply (21); the fuse (17) is connected to the power switch (15) and the contactor contact (20); the air switch (16) is connected to a single phase of the power switch (15) and a power supply neutral line; the fan motor (4) The temperature controller (14) is connected to the air switch (16); the I1 terminal of the temperature controller (14) is connected to the single phase of the 380V AC power supply (21); the I2 terminal of the temperature controller (14) is connected to the neutral line of the 380V AC power supply (21); the Out1 terminal of the temperature controller (14) is connected to the A1 terminal of the contactor (18); the Out2 terminal of the temperature controller (14) is connected to the A2 terminal of the contactor (18); and the temperature measuring resistor (19) is connected to the terminals P3, P2 and P1 of the temperature controller (14).

Images