Device and method for simulating accelerated aging of core rod based on ultrasonic spraying

Abstract

The invention belongs to the technical field of aging evaluation and life prediction of power equipment, and particularly discloses a device and a method for simulating accelerated aging of a core rod based on ultrasonic spraying. The device comprises an ultrasonic spraying system and a temperature and humidity control box body, and a three-point bending sample clamp is arranged in the temperature and humidity control box body and used for clamping a core rod sample and applying three-point bending force to the core rod sample; the ultrasonic spraying system is arranged on one side of the temperature and humidity control box body and is used for spraying mist to the surface of the core rod test object; and the high-voltage power supply is arranged on one side of the temperature and humidity control box body, is connected with the three-point bending sample clamp, and is used for applying voltage to the two ends of the core rod sample through the three-point bending sample clamp. According to the invention, the aging environment with the superposition of four factors of temperature, humidity, discharge and external force is set according to the operation condition of the place where the aging faults of the core rod occur frequently, the aging process of the core rod which accords with the actual aging mechanism can be obtained, and reference is provided for the aging and life analysis of the core rod.

Description

Technical Field

[0001] The invention relates to the technical field of power equipment aging assessment and life prediction, and in particular to a device and method for simulating accelerated aging of a core rod based on ultrasonic spray. Background Art

[0002] Composite insulators are important components used to isolate conductors and towers in power systems. They are usually composed of a fiberglass core rod that provides mechanical support internally and a high-temperature vulcanized silicone rubber outer layer. In the composition of composite insulators, the fiberglass core rod is an important component that bears mechanical loads and has the main insulation function. With long-term operation, composite insulators age over a long period of time under multi-factor conditions. The aging of the outer sheath causes moisture intrusion, resulting in discharge, heat, and water vapor on the surface of the internal fiberglass core rod, causing the core rod to age rapidly under the influence of multiple factors, ultimately leading to severe accidents such as breakdown and fracture, which bring a series of hazards to the safe operation of the power system.

[0003] Due to the uncontrollability and unobservability of on-site aging, simulating the accelerated aging of core rods in the laboratory is of great research significance for restoring the aging process, predicting the progress of aging, and guiding on-site operation and maintenance. According to the analysis results of the causes of abnormal heating of 500kV composite insulators in the paper "Analysis of the Causes of Composite Insulator Decay and Heating Aging", the aging of FRP core rods comes from the long-term superposition of multiple weak stresses such as interface discharge, water vapor intrusion, and local heating. Therefore, the simulation of the core rod aging process in the laboratory should be as close to the on-site situation as possible to restore the aging process. The existing artificial accelerated aging technology has a relatively thorough study on the mechanism of core rod aging. However, few people pay attention to the restoration of on-site operation, resulting in the failure to obtain aging characteristics that are closer to reality. In the scientific paper "Research on Accelerated Thermal Oxygen Aging Characteristics of Carbon Fiber Composite Core Rods", the thermal oxygen accelerated aging method was used to test the stress changes of the core rods under aging conditions of 170°C, 185°C and 200°C, but the factors were not considered comprehensively, ignoring the effects of electrical stress, wet stress and bending stress on core rod aging; the invention patent "A Complex Environment Simulation Experimental Device for Composite Insulators with Combined Cabins" specifically studied the aging process of insulators in the end environment, and transferred insulators through multiple test chambers to provide different test conditions to achieve multi-factor aging, but the applied conditions were too harsh, which changed the aging mechanism of the core rod and did not conform to the actual aging process; the invention patent "A Multi-factor Aging Experimental Device and Prediction Method for Silicone Rubber Composite Insulator Umbrella Sheath" targets the operating environment of the insulator shed sheath, and realizes the multi-factor aging of the insulator by controlling the temperature, humidity and ultraviolet radiation intensity, but it mainly targets the insulator sheath and the insulator as a whole, and does not take the operating environment of the core rod into consideration. The above methods have explored how to simulate field operation conditions for artificial accelerated aging, but the following problems still exist in the accelerated aging of core rods: 1) The external stress applied is single or a certain stress is missing, which cannot completely restore the field operation; 2) The conditions are too harsh, which to a certain extent destroys the degradation mechanism of the core rod during the field aging process, resulting in breakdown and burning of the core rod surface, failing to achieve the basic conditions for long-term weak stress aging of the core rod, and failing to restore the field aging effect; 3) The existing technology mostly considers the composite insulator as a whole, lacks specific improvements for core rod aging, fails to fully consider the conditions for the occurrence of core rod aging, and the accuracy of the artificial aging analysis results is questionable. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a device and method for simulating accelerated core rod aging based on ultrasonic spray. An aging environment in which four factors of temperature, humidity, discharge and external force are superimposed is set according to the operating conditions of areas where core rod aging failures are frequent. The ultrasonic spray system adopted can control the core rod surface to prevent a breakdown path from being formed, which is more in line with the slow intrusion behavior of water vapor in actual operation, so as to obtain a core rod aging process that is more in line with the actual aging mechanism, and provide a reference for core rod aging and life analysis.

[0005] The present invention adopts the following technical solution.

[0006] In the first aspect, the present invention provides a device for simulating accelerated aging of a core rod based on ultrasonic spray, comprising: an ultrasonic spray system and a temperature and humidity control box, wherein a three-point bending specimen fixture is arranged inside the temperature and humidity control box, for clamping the core rod specimen and applying a three-point bending force thereto; the ultrasonic spray system is arranged on one side of the temperature and humidity control box, and its spray direction is toward a spray opening window arranged in the temperature and humidity control box, for spraying spray on the surface of the core rod specimen; the device also includes a high-voltage power supply, which is arranged on one side of the temperature and humidity control box and connected to the three-point bending specimen fixture, for applying voltage to both ends of the core rod specimen through the three-point bending specimen fixture.

[0007] Preferably, the ultrasonic spray system comprises: a conductivity liquid tank, an infusion system, an ultrasonic generator and a fan-shaped atomizing nozzle; one end of the infusion system is connected to the conductivity liquid tank, and the other end is connected to the ultrasonic generator, and is used to transport the conductivity liquid in the conductivity liquid tank to the ultrasonic generator; a fan-shaped atomizing nozzle is provided at the end of the ultrasonic generator, and the fan-shaped atomizing nozzle faces the spray opening window, and is used to generate spray and spray the spray onto the surface of the core rod sample.

[0008] Preferably, the three-point bending specimen fixture comprises: a fixture metal crossarm, a fixture metal base and an insulating adjustable-distance rod body; the fixture metal crossarm and the fixture metal base are connected through the insulating adjustable-distance rod body, and a clamping area for clamping the core rod specimen is formed between the fixture metal crossarm, the fixture metal base and the insulating adjustable-distance rod body; metal fixtures are provided on one side of the fixture metal crossarm and the fixture metal base close to the clamping area, which are used to provide vertical pressure to two upper and lower position points on one side of the core rod specimen; an insulating three-point bending fixture is provided on one side of the insulating adjustable-distance rod body close to the clamping area, which is used to apply vertical pressure to the other side of the core rod specimen.

[0009] Preferably, the clamp metal cross arm and the clamp metal base are both arranged horizontally, one end of the insulating adjustable distance rod body is vertically fixedly connected to the clamp metal base, and the other end is slidably connected to the clamp metal cross arm for adjusting the height of the clamping area.

[0010] Preferably, the metal fixture is arranged in an isosceles triangle, and its base is vertically connected to the metal cross arm of the clamp or the metal base of the clamp through a connecting rod, and the connecting line between the connecting rods of the two metal fixtures is perpendicular to the metal base of the clamp; the vertex of the metal fixture is used to apply vertical pressure to the side surface of the core rod specimen.

[0011] Preferably, the insulating three-point bending fixture is fixedly installed on one end of the bending force applying crossarm, the bending force applying crossarm can be installed on the insulating adjustable distance rod body so as to be movable left and right in the horizontal direction, and the bending force applying crossarm is arranged on the horizontal bisector plane of the clamping area; the insulating adjustable distance rod body is provided with an adjusting nut for adjusting the moving position of the bending force applying crossarm.

[0012] Preferably, the insulating three-point bending fixture is arranged in an isosceles triangle, the base of which is vertically fixedly connected to one end of the bending force applying cross arm, and the vertex of which is used to apply vertical pressure to the side surface of the core rod specimen.

[0013] Preferably, the high-voltage power supply is connected to the metal cross arm and metal base of the fixture located inside the temperature and humidity control box through two wires; an insulating sleeve is provided at the contact point between each wire and the temperature and humidity control box.

[0014] Preferably, a temperature and humidity control panel is provided outside the temperature and humidity control box, and the temperature and humidity control panel is connected to the ultrasonic spray system and is used to control the switch of the ultrasonic spray system to adjust the temperature and humidity inside the temperature and humidity control box.

[0015] In a second aspect, the present invention provides a method for simulating accelerated aging of a mandrel based on ultrasonic spray, using the aforementioned device for simulating accelerated aging of a mandrel based on ultrasonic spray, comprising the following steps:

[0016] The mandrel specimen is mounted on a three-point bending specimen fixture located inside a temperature and humidity control box, and the pressure value applied by the three-point bending specimen fixture to the mandrel specimen is adjusted to provide bending force application conditions to the mandrel specimen;

[0017] Start the high voltage power supply, apply voltage to both ends of the mandrel test piece, and provide conditions for applying electrical stress;

[0018] Start the ultrasonic atomization system to spray the surface of the core rod test piece to provide the required temperature and humidity conditions;

[0019] Observe the aging process of the core rod specimen and analyze the aging condition and life of the core rod specimen.

[0020] Compared with the prior art, the beneficial effect of the present invention is that the present invention can provide discontinuous micro-discharge, aging conditions of bending force application and temperature and humidity control conditions to the core rod sample at the same time by setting an ultrasonic spray system, a three-point bending sample fixture and a high-voltage power supply, and provides an aging environment with four factors superimposed on temperature-humidity-discharge-external force. By adjusting factors such as spray strength and bending stress, flexible and controllable environmental simulations such as stress environment, rapid temperature change environment, day and night high and low temperature crossover, high corona environment, and high humidity and heat environment can be achieved, thereby restoring the operating conditions of the core rod aging failure prone areas. At the same time, the ultrasonic spray system provided by the present invention will not form a breakdown circuit on the core rod surface, and is more in line with the slow intrusion process of water vapor in actual operation, so that it is more in line with the core rod aging mechanism, which is conducive to the analysis of the aging condition and life of the core rod.

[0021] In order to further facilitate the analysis of the aging of the core rod sample, the present invention sets a temperature and humidity control panel on the surface of the temperature and humidity control box, and controls the switch of the ultrasonic spray system through the temperature and humidity control panel, so that the temperature and humidity control box can maintain constant temperature and humidity conditions. By setting a spray opening window on the surface of the temperature and humidity control box, it is not only convenient to spray the core rod surface, but also convenient for the staff to observe the aging of the core rod from the outside, so as to ensure the safety of the experimental process and visualize the whole process. The user can replace and take samples at any time to study different periods of aging. At the same time, the temperature and humidity changes in the temperature and humidity control box and the aging of the surface of the glass fiber reinforced plastic core rod sample are monitored at all times, providing a basis for manual experiments of operation and maintenance and core rod life prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a device for accelerating aging of a simulated mandrel based on ultrasonic spray in the present invention;

[0023] Reference numerals in the figures:

[0024] 1. Conductivity liquid tank; 2. Infusion system; 3. Ultrasonic generator; 4. Fan-shaped atomizing nozzle; 5. Temperature and humidity control box; 6. Spray opening window; 7. Temperature and humidity control panel; 8. Metal cross arm of the clamp; 9. Metal fixer; 10. Metal base of the clamp; 11. Insulated bending fixer; 12. Adjusting nut; 13. Bending force applying cross arm; 14. Insulated adjustable distance rod; 15. Insulating sleeve; 16. High voltage power supply; 17. Mandrel test piece. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0026] like Figure 1 As shown, embodiment 1 of the present invention provides a device for simulating accelerated aging of a core rod based on ultrasonic spray, comprising: an ultrasonic spray system, a temperature and humidity control box 5 and a high voltage power supply 16.

[0027] A three-point bending specimen fixture is provided inside the temperature and humidity control box 5 for clamping the mandrel specimen 17. A spray opening window 6 communicating with the interior of the temperature and humidity control box 5 is provided on one side of the temperature and humidity control box 5, and a temperature and humidity control panel 7 is also provided on the outer surface of one side of the temperature and humidity control box 5 for adjusting the temperature and humidity inside the temperature and humidity control box 5, thereby simulating different temperature and humidity environments.

[0028] The ultrasonic spray system is arranged outside the temperature and humidity control box 5 and close to the spray opening window 6. The ultrasonic spray system is connected to the temperature and humidity control panel 7 and is used to spray spray toward the spray opening window 6, thereby increasing the humidity inside the temperature and humidity control box 5 and reducing the temperature inside the temperature and humidity control box 5, thereby adjusting the temperature and humidity environment inside the temperature and humidity control box 5, so that the temperature and humidity inside the temperature and humidity control box 5 is maintained at a constant temperature and humidity condition.

[0029] The high voltage power supply 16 is arranged outside the temperature and humidity control box 5 and connected to the three-point bending specimen fixture to provide voltage to both ends of the core rod specimen, applying discontinuous micro discharge thereto to simulate the partial discharge during the operation of the composite insulator.

[0030] The ultrasonic spray system includes: a conductive liquid tank 1, an infusion system 2, an ultrasonic generator 3 and a fan-shaped atomizing nozzle 4. The conductive liquid tank 1 is filled with conductive liquid, and the conductive liquid is connected to the ultrasonic generator 3 through the infusion system 2. The end of the ultrasonic generator 3 is provided with a fan-shaped atomizing nozzle 4. The conductive liquid entering the ultrasonic generator 3 and the fan-shaped atomizing nozzle 4 generates an extremely fine spray under the action of ultrasonic atomization, and the spray passes through the spray opening window 6 and is evenly sprayed on the surface of the core rod sample 17 located inside the temperature and humidity control box 5.

[0031] In a preferred but non-limiting embodiment of the present invention, the spray water droplet size should be adjusted to less than 10 microns, and the fan-shaped nozzle should be 12 cm away from the test piece, so that no breakdown path is formed on the core rod surface, ensuring that no breakdown behavior occurs on the core rod surface.

[0032] Furthermore, the three-point bending specimen fixture includes: a fixture metal cross arm 8, a metal fixture 9, a fixture metal base 10, an insulating three-point bending fixture 11, an adjusting nut 12, a bending force applying cross arm 13 and an insulating adjustable distance rod body 14. Among them, the fixture metal cross arm 8 and the fixture metal base 10 are both arranged horizontally. Metal fixtures 9 are arranged at the bottom of the fixture metal cross arm 8 and the top of the fixture metal base 10. The two metal fixtures 9 are arranged in the same vertical plane and are both located on the left or right side of the core rod specimen 17, and are used to provide vertical pressure to the core rod specimen 17 at two upper and lower positions from the left or right side of the core rod specimen 17.

[0033] In a preferred but non-limiting embodiment of the present invention, the metal fixture 9 is in the shape of an isosceles triangle, the base of which is vertically connected to the metal cross arm 8 or the fixture metal base 10 through a connecting rod, and the vertex of the isosceles triangle is used to contact the side surface of the sample core rod 17 and apply vertical pressure.

[0034] The bottom of the insulating distance adjusting rod body 14 is vertically fixedly connected to the clamp metal base 10, and the top can movably pass through the clamp metal cross arm 8. By moving the position of the clamp metal cross arm 8 on the insulating distance adjusting rod body 14, the height of the clamping area can be adjusted, thereby adjusting the position of the pressure application point. A clamping area for clamping the core rod sample 17 is formed between the clamp metal cross arm 8, the clamp metal base 10, the two metal fixtures 9 and the insulating distance adjusting rod body 14. A bending force applying cross arm 13 is provided in the middle of the insulating distance adjusting rod body 14, and the bending force applying cross arm 13 is located on the horizontal bisector of the clamping area. The bending force applying cross arm 13 can move left and right in the horizontal direction, and the insulating distance adjusting rod body 14 is fixedly installed with an adjusting nut 12 for adjusting the moving position of the bending force applying cross arm 13.

[0035] An insulating bending fixture 11 is provided on the side of the bending force applying cross arm 13 close to the clamping area, and the insulating bending fixture 11 is used to apply vertical pressure to the side of the sample core rod 17 away from the metal fixture 9. The two metal fixtures 9 and one insulating bending fixture 11 work together on both sides of the sample core rod 17 to achieve three-point bending clamping of the sample core rod.

[0036] Furthermore, the insulating bending fixture 11 is also arranged in an isosceles triangle, and its base is vertically fixedly connected to one end of the bending force applying cross arm 13 close to the clamping area. The insulating bending fixture 11 can be driven to move by rotating the adjusting nut 12, thereby adjusting the pressure value applied by the insulating bending fixture 11 to the test core rod 17, and the pressure value should correspond to the line grade and insulator size to be simulated.

[0037] Furthermore, the insulating curved fixture 11 is preferably made of epoxy resin insulating material.

[0038] The metal cross arm 8 of the clamp and the metal base 10 of the clamp are respectively connected to the high-voltage power supply 16 located outside the temperature and humidity control box 5 through wires, and the wires are connected to the grounding interface of the high-voltage power supply 16 to form a grounding terminal electrode. An insulating sleeve 15 is provided on the outside of the wire. Through the high-voltage power supply 16 and the wire, the metal cross arm 8 of the clamp, the metal base 10 of the clamp and the two metal fixtures 9 are connected to the high-voltage electrode. The high-voltage power supply 16 can provide voltage to both ends of the sample core rod, and perform discontinuous micro discharge on it to simulate the partial discharge during the operation of the composite insulator.

[0039] Embodiment 2 of the present invention provides a method for accelerating aging of a mandrel based on ultrasonic spray simulation, using the device for accelerating aging of a mandrel based on ultrasonic spray simulation in Embodiment 1, comprising the following steps:

[0040] Step 1, installing the mandrel sample 17 on the three-point bending sample fixture located inside the temperature and humidity control box 5, and adjusting the pressure value applied by the three-point bending sample fixture to the mandrel sample to provide bending force application conditions for the mandrel sample;

[0041] Step 2: Start the high voltage power supply 16 to apply voltage to both ends of the mandrel test piece 17 to provide electrical stress application conditions;

[0042] It should be noted that the voltage applied by the high voltage 16 should be such that no breakdown discharge occurs on the surface of the core rod.

[0043] Step 3, start the ultrasonic spray system through the temperature and humidity control panel 7, spray the surface of the mandrel sample, control the temperature and humidity of the environment where the mandrel sample is located, and accelerate the aging of the mandrel sample;

[0044] Step 4: Observe the aging process of the sample core rod and analyze the aging condition and life of the core rod.

[0045] In a preferred but non-limiting embodiment of the present invention, step 1 comprises the following steps:

[0046] Step 1.1, install the mandrel sample 17 on the three-point bending sample fixture inside the temperature and humidity control box 5, so that the mandrel sample 17 is between the two metal fixtures 9 and the insulating bending fixture 11;

[0047] Step 1.2: Adjust the position of the insulation bending fixture 11 to adjust the pressure value applied to the core rod sample 17.

[0048] Compared with the prior art, the beneficial effect of the present invention is that the present invention can provide discontinuous micro-discharge, aging conditions of bending force application and temperature and humidity control conditions to the core rod sample 17 at the same time by setting an ultrasonic spray system, a three-point bending sample fixture and a high-voltage power supply 16, and provide an aging environment with four factors superimposed on temperature-humidity-discharge-external force. By adjusting factors such as the spray intensity and the bending stress, flexible and controllable environmental simulations such as stress environment, rapid temperature change environment, day and night high and low temperature crossing, high corona environment, and high humidity and heat environment can be achieved, thereby restoring the operating conditions of the core rod aging failure prone areas. At the same time, the ultrasonic spray system provided by the present invention will not form a breakdown circuit on the core rod surface, and is more in line with the slow intrusion process of water vapor in actual operation, so that it is more in line with the core rod aging mechanism, which is conducive to the analysis of the aging condition and life of the core rod.

[0049] In order to further facilitate the analysis of the aging of the core rod sample, the present invention sets a temperature and humidity control panel 7 on the surface of the temperature and humidity control box, and controls the switch of the ultrasonic spray system through the temperature and humidity control panel 7, so that the temperature and humidity control box 5 can maintain constant temperature and humidity conditions. By setting a spray opening window 6 on the surface of the temperature and humidity control box 7, it is not only convenient to spray the surface of the core rod sample 17, but also convenient for the staff to observe the aging of the core rod from the outside, so as to ensure the safety of the experimental process and visualize the whole process. The user can replace and take samples at any time to study different periods of aging. At the same time, the temperature and humidity changes in the temperature and humidity control box and the aging of the surface of the glass fiber reinforced plastic core rod sample are monitored at all times, providing a basis for manual experiments on operation and maintenance and core rod life prediction.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A device for simulating accelerated aging of a mandrel based on ultrasonic spray, comprising: The ultrasonic spray system and the temperature and humidity control box (5) are characterized by: A three-point bending specimen fixture is arranged inside the temperature and humidity control box (5) for clamping the mandrel specimen (17) and applying a three-point bending force thereto; The ultrasonic spray system is arranged on one side of the temperature and humidity control box (5), and its spray direction is toward the spray opening window (6) arranged on the temperature and humidity control box (5), and is used to spray the spray onto the surface of the core rod sample (17); The device also includes a high-voltage power supply (16), which is arranged on one side of the temperature and humidity control box (5) and connected to a three-point bending specimen fixture, and is used to apply voltage to both ends of the mandrel specimen (17) through the three-point bending specimen fixture.

2. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to claim 1, characterized in that: The ultrasonic spray system comprises: a conductive liquid tank (1), a liquid infusion system (2), an ultrasonic generator (3) and a fan-shaped atomizing nozzle (4); One end of the infusion system (2) is connected to the conductive liquid tank (1), and the other end is connected to the ultrasonic generator (3), and is used to transport the conductive liquid in the conductive liquid tank (1) to the ultrasonic generator (3); The end of the ultrasonic generator (3) is provided with a fan-shaped atomizing nozzle (4), which faces the spray opening window (6) and is used to generate spray and spray the spray onto the surface of the core rod sample (17).

3. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to claim 1 or 2, characterized in that: The three-point bending specimen fixture comprises: a fixture metal cross arm (8), a fixture metal base (10) and an insulating adjustable distance rod body (14); the fixture metal cross arm (8) and the fixture metal base (10) are connected via the insulating adjustable distance rod body (14), and a clamping area for clamping the core rod specimen is formed between the fixture metal cross arm (8), the fixture metal base (10) and the insulating adjustable distance rod body (14); A metal fixture (9) is provided on one side of the clamp metal cross arm (8) and the clamp metal base (10) close to the clamping area, and is used to provide vertical pressure to two upper and lower positions on one side of the mandrel test piece (17); An insulating three-point bending fixture (11) is provided on one side of the insulating spacing rod body (14) close to the clamping area, and is used to apply vertical pressure to the other side of the core rod sample (17).

4. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to claim 3, characterized in that: The clamp metal cross arm (8) and the clamp metal base (10) are both arranged horizontally, one end of the insulating adjustable distance rod body (14) is vertically fixedly connected to the clamp metal base (10), and the other end is slidably connected to the clamp metal cross arm (8) for adjusting the height of the clamping area.

5. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to claim 4, characterized in that: The metal fixture (9) is arranged in the shape of an isosceles triangle, and its bottom side is vertically connected to the metal cross arm (8) of the clamp or the metal base (10) of the clamp through a connecting rod, and the connecting line between the connecting rods of the two metal fixtures (9) is perpendicular to the metal base (10) of the clamp; The apex of the metal fixture (9) is used to apply vertical pressure to the side surface of the mandrel specimen (17).

6. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to claim 3, characterized in that: The insulating three-point bending fixture (11) is fixedly mounted on one end of a bending force applying cross arm (13), the bending force applying cross arm (13) is mounted on the insulating spacing rod body (14) so ​​as to be movable left and right in the horizontal direction, and the bending force applying cross arm (13) is arranged on a horizontal bisector of the clamping area; The insulating spacing rod body (14) is provided with an adjusting nut (12) for adjusting the moving position of the bending force applying cross arm (13).

7. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to claim 6, characterized in that: The insulating three-point bending fixture (11) is arranged in the shape of an isosceles triangle, the base of which is vertically fixedly connected to one end of the bending force applying cross arm (13), and the vertex of which is used to apply vertical pressure to the side surface of the core rod sample (17).

8. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to claim 3, characterized in that: The high-voltage power supply (16) is connected to a fixture metal cross arm (8) and a fixture metal base (10) located inside the temperature and humidity control box (5) via two wires; an insulating sleeve (15) is provided at the contact point between each wire and the temperature and humidity control box (5).

9. The device for simulating accelerated aging of a mandrel based on ultrasonic spray according to any one of claims 1 to 8, characterized in that: A temperature and humidity control panel (7) is arranged outside the temperature and humidity control box (5), and the temperature and humidity control panel (7) is connected to the ultrasonic spray system and is used to control the switch of the ultrasonic spray system to adjust the temperature and humidity inside the temperature and humidity control box (5).

10. A method for simulating accelerated aging of a mandrel based on ultrasonic spray, using the device for simulating accelerated aging of a mandrel based on ultrasonic spray according to any one of claims 1 to 9, characterized in that: The following steps are involved: The mandrel test piece (17) is mounted on a three-point bending test piece fixture located inside the temperature and humidity control box (5), and the pressure value applied by the three-point bending test piece fixture to the mandrel test piece (17) is adjusted to provide bending force application conditions for the mandrel test piece; Starting a high voltage power supply (16) to apply voltage to both ends of the mandrel test piece (17) to provide electrical stress application conditions; Starting the ultrasonic atomization system to spray the surface of the mandrel sample (17) to provide the required temperature and humidity conditions; The aging process of the core rod sample (17) is observed, and the aging condition and life of the core rod sample (17) are analyzed.

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