Pressure-sensitive material, and pressure-sensitive material-based method for identifying insulating gas leakage

Abstract

A method for visually identifying an insulating gas leakage, comprising the following steps: applying a pressure-sensitive material to the surface of an inflatable device using an insulating gas, wherein the pressure-sensitive material has set toughness and ductility, and the color of the pressure-sensitive material changes after the pressure-sensitive material deforms; and when the pressure-sensitive material bulges from the surface of the inflatable device and the color of the pressure-sensitive material changes, visually finding that the insulating gas leaks, and immediately performing treatment. Also provided is a pressure-sensitive material for insulating gas leakage detection. The pressure-sensitive material comprises the following components: an adhesive material, a foaming material, a piezochromic material, and a forming agent. The mass percentage of the adhesive material is 70% to 80%, the mass percentage of the piezochromic material is 8% to 12%, and the mass percentage of the foaming material is not less than 5% of the total mass. Also provided is a preparation method for the pressure-sensitive material for insulating gas leakage detection.

Description

Varistor materials and methods for identifying gas leaks in insulation based on varistor materials Technical Field

[0001] This invention belongs to the field of power equipment safe operation technology, and more specifically, relates to a varistor material and a method for identifying insulating gas leaks based on the varistor material. Background Technology

[0002] Sulfur hexafluoride (SF6) gas possesses excellent insulation and arc-quenching properties, and its insulating properties significantly reduce the volume and footprint of electrical equipment, leading to its widespread use in the power industry both domestically and internationally. However, SF6 has an extremely strong greenhouse effect; the greenhouse effect of a single molecule of SF6 is 23,500 times that of carbon dioxide. Preventing the direct emission of SF6 into the atmosphere is crucial for its effective use. Long-term use of SF6-filled equipment can easily lead to leaks. Because the gas is colorless and odorless, it is difficult to detect directly. Traditional leak detection methods rely on methods such as sealing, bottle shut-off, and pressure conversion, all of which require prolonged monitoring and are not intuitive enough to directly detect SF6 leaks.

[0003] Prior art document 1 (CN 116371226 A) discloses a method for preparing a leak detection fluid for pressure leak detection of transformer tanks, used to check for leaks in transformers and their accessories. It is worth noting that the prior art, represented by prior art document 1, can only test whether there is already a leak, but cannot detect it immediately when it begins to leak, and cannot recover the leaked gas.

[0004] In order to detect whether sulfur hexafluoride (SF6) is leaking in equipment in real time, and to deal with it in a timely manner to prevent SF6 from being released into the atmosphere, this invention proposes a method for intuitive identification of SF6 leaks. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a varistor material and a method for identifying insulating gas leaks based on the varistor material.

[0006] The present invention adopts the following technical solution.

[0007] The first aspect of this invention provides a method for visually identifying insulating gas leaks, comprising the following steps:

[0008] A pressure-sensitive material is applied to the surface of an inflation device that uses an insulating gas. The pressure-sensitive material has a set toughness and ductility and changes color after deformation.

[0009] When the pressure-sensitive material bulges and changes color from the surface of the inflation device, a leak of insulating gas is visually detected and immediately addressed.

[0010] Preferably, the insulating gas is sulfur hexafluoride or a mixture of sulfur hexafluoride and nitrogen.

[0011] Preferably, the pressure-sensitive material is adhesive, which is adhered to the surface of the inflation device and fits seamlessly with the inflation device after adhesion.

[0012] Alternatively, the pressure-sensitive material can also be a coating material, which is sprayed onto the surface of the inflation device and dries rapidly upon contact with air to become a thin film covering the surface of the device, adhering tightly to the device without gaps.

[0013] Preferably, after a leak occurs, the bulging and discolored portion is recovered, and the insulating gas inside the bulge is collected to prevent it from being released into the atmosphere. At the same time, the leak point of the inflation equipment is dealt with in a timely manner to prevent further leakage.

[0014] A second aspect of the present invention provides a pressure-sensitive material for detecting insulating gas leaks, applied to the aforementioned method for visually identifying insulating gas leaks, wherein the pressure-sensitive material comprises: an adhesive material, a foaming material, a pressure-sensitive color-changing material, and a molding agent;

[0015] Adhesive materials should account for 70% to 80% of the total mass; pressure-sensitive color-changing materials should account for 8% to 12% of the total mass; and foaming materials should account for no less than 5% of the total mass.

[0016] Preferably, the adhesive material is an ethyl acetate compound, the foaming material is a surfactant, and the pressure-sensitive color-changing material is a fluorane lactone compound, a methanephthalein compound, or a tetraphenylethylene derivative.

[0017] Preferably, the adhesive material is polyvinyl acetate emulsion, the foaming material is sodium alkylbenzene sulfonate, and the pressure-sensitive color-changing material is crystal violet lactone, tetraphenylethylene-imidazolium derivative, or tetraphenylethylene-quinoline derivative.

[0018] A third aspect of the present invention provides a method for preparing a varistor material for detecting insulating gas leaks, comprising the following steps:

[0019] Step 1: Weigh the set mass of adhesive material, place it in the reaction vessel, add a stir bar, and heat to the set temperature;

[0020] Step 2: Maintain the reaction temperature, add the set mass of pressure-sensitive color-changing material to the adhesive material, and continue until it is completely dissolved and homogeneous;

[0021] Step 3: Add the set amount of foaming material to the mixture prepared in Step 2, and stir until well mixed;

[0022] Step 4: Add the molding agent to the mixture prepared in Step 3 and stir continuously to keep the mixture homogeneous and prevent lumps or granules from forming.

[0023] Step 5: Once the temperature has cooled to room temperature, seal and store the prepared mixture for later use.

[0024] Preferably, in step 1, a 10m mass of polyvinyl acetate solution is weighed and placed in a reaction vessel. A stir bar is added, and the temperature is raised to about 70°C. While stirring, a small amount of polyvinyl alcohol, polyvinyl formal, potassium persulfate, and starch are added for modification to improve the toughness and temperature adaptability of the polyvinyl acetate solution.

[0025] Preferably, in step 2, the reaction temperature is maintained at 70℃±2℃, and a mass of approximately m tetraphenylethylene-imidazolium derivative is added to the modified polyvinyl acetate solution in multiple portions until it is completely dissolved and homogeneous.

[0026] Preferably, in step 3, the pH value is adjusted to be close to neutral, and 0.5 m to m of sodium alkylbenzene sulfonate is added to the mixed liquid mixture and stirred until homogeneous.

[0027] Preferably, in step 4, the molding agent is added dropwise to the mixed liquid substance in small amounts multiple times while continuously stirring to maintain a uniform state of the mixture, preventing the formation of lumps or clumps of particles. The mixed liquid tends to become viscous. When the viscosity is good and the mixture still has fluidity, heating and stirring are stopped.

[0028] Compared with the prior art, the beneficial effects of the present invention include at least the following: after the material of the present invention is sprayed or adhered to the surface of the equipment, once there is a sulfur hexafluoride leak, bubbling and discoloration will be detected, and the leaked sulfur hexafluoride can be wrapped up for easy recovery, preventing sulfur hexafluoride gas from leaking into the atmosphere; the timely and intuitive detection of the leak point can prevent sulfur hexafluoride from leaking into the atmosphere and avoid the greenhouse gas sulfur hexafluoride from being emitted into the atmosphere and causing harm to the environment. Attached Figure Description

[0029] Figure 1 shows the changes before and after the sulfur hexafluoride equipment leaked.

[0030] Figure 2 is a flowchart of the preparation method for sensitive materials. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0032] Figure 1 is a schematic diagram of the sulfur hexafluoride equipment before and after leakage according to an embodiment of the present invention. The pressure-sensitive material is coated or pasted on the connection of the equipment that is prone to leakage. When sulfur hexafluoride leakage occurs, the pressure-sensitive material is blown into bubbles by the gas and its color changes. The maintenance personnel can visually detect the sulfur hexafluoride leakage and deal with it immediately.

[0033] Specifically, as shown in Figure 1, Embodiment 1 of the present invention provides a method for visually identifying insulating gas leaks, comprising the following steps:

[0034] A pressure-sensitive material is applied to the surface of an inflation device that uses an insulating gas. The pressure-sensitive material has a set toughness and ductility and changes color after deformation.

[0035] When the pressure-sensitive material bulged and discolored from the surface of the inflation device, a sulfur hexafluoride leak was visually detected and immediately addressed.

[0036] Preferably, the insulating gas is sulfur hexafluoride or a mixture of sulfur hexafluoride and nitrogen.

[0037] Preferably, a pressure-sensitive material is applied to the surface of the connection points of the inflation device that are prone to leakage.

[0038] Preferably, the pressure-sensitive material is adhesive, which can be easily adhered to the surface of the inflatable device, and after adhesion, it fits tightly to the device without gaps.

[0039] Alternatively, the pressure-sensitive material can be a coating material, which is sprayed onto the surface of the inflation device and dries rapidly upon contact with air to become a thin film covering the surface of the device, adhering tightly to the device without gaps.

[0040] Preferably, the pressure-sensitive material is for single use only. It becomes ineffective when it deforms or changes color due to pressure changes. If a leak needs to be tested again, a new pressure-sensitive material needs to be applied.

[0041] Preferably, an expiration date is set for the pressure-sensitive material. After the expiration date, the pressure-sensitive material needs to be replaced with a new one to better monitor whether there are leaks in the equipment.

[0042] When sulfur hexafluoride leaks, the pressure-sensitive material bulges and changes color from the surface of the inflation equipment, which can be visually detected by inspection personnel. Preferably, after a leak occurs, the bulging and discolored part is recovered, and the sulfur hexafluoride gas inside the bulge is collected to prevent it from being released into the atmosphere. At the same time, the leak point of the inflation equipment is dealt with in a timely manner to prevent further leakage.

[0043] Embodiment 3 of the present invention provides a pressure-sensitive material for detecting insulating gas leaks, comprising: an adhesive material, a foaming material, a pressure-sensitive color-changing material, and a molding agent.

[0044] Preferably, the adhesive material is the main reagent, and the amount added should account for 70% to 80% of the final synthetic product; the proportion of pressure-sensitive color-changing material should be about 10%, for example, but not limited to 8% to 12%. Too high a content will affect the viscosity and foaming properties of the material, while too low a content will result in indistinct color change; the foaming material should be no less than 5% of the total amount. A higher content makes it easier to foam, but the toughness of the material decreases and it is easy to break. A lower content makes it less sensitive to leakage of low-content sulfur hexafluoride.

[0045] Preferably, the adhesive material is an ethyl acetate compound, such as, but not limited to, polyvinyl acetate emulsion, which mainly serves to ensure that the material can be reliably adhered to the equipment housing;

[0046] Preferably, the foaming material is a surfactant, such as, but not limited to, sodium alkylbenzene sulfonate, whose main function is to allow the material to bubble and collect gas after gas leakage, while also exhibiting deformation after gas leakage;

[0047] Preferably, the pressure-sensitive color-changing material is a fluorane lactone compound, a methanephthalein compound, a tetraphenylethylene derivative, etc., preferably but not limited to, such as crystal violet lactone, tetraphenylethylene-imidazolium derivative, tetraphenylethylene-quinoline derivative. Its main function is to change color after the material is subjected to pressure changes, so that gas leakage can be more intuitively displayed.

[0048] Preferably, the molding agent is used to better shape the mixture, such as, but not limited to, a mixture of sodium chloride, surfactant, water, etc.

[0049] As shown in Figure 2, Embodiment 4 of the present invention provides a method for preparing a varistor material for detecting insulating gas leaks, characterized by comprising the following steps:

[0050] Step 1: Weigh the set mass of adhesive material, place it in the reaction vessel, add a stir bar, and heat to the set temperature.

[0051] Preferably, in step 1, a small amount of modifying material is added under stirring to improve the toughness and temperature adaptability of the polyvinyl acetate solution.

[0052] More preferably, in step 1, a 10m mass of polyvinyl acetate solution is weighed and placed in a reaction vessel. A stir bar is added, and the temperature is raised to about 70°C. While stirring, a small amount of polyvinyl alcohol, polyvinyl formal, potassium persulfate, and starch are added for modification to improve the toughness and temperature adaptability of the polyvinyl acetate solution.

[0053] Step 2: Maintain the reaction temperature, add the set mass of pressure-sensitive color-changing material to the adhesive material until it is completely dissolved and homogeneous.

[0054] Preferably, in step 2, the reaction temperature is maintained at 70℃±2℃, and a mass of approximately m tetraphenylethylene-imidazolium derivative is added to the modified polyvinyl acetate solution in multiple portions until it is completely dissolved and homogeneous.

[0055] Step 3: Add the set amount of foaming material to the mixture prepared in Step 2, and stir until well mixed;

[0056] Preferably, in step 3, the pH value is adjusted to be close to neutral, and 0.5 m to m of sodium alkylbenzene sulfonate is added to the mixed liquid mixture and stirred until homogeneous.

[0057] Step 4: Add the molding agent to the mixture prepared in Step 3 and stir continuously to keep the mixture homogeneous and prevent lumps or granules from forming.

[0058] Preferably, in step 4, the molding agent is added dropwise to the mixed liquid substance in small amounts multiple times while continuously stirring to maintain a uniform state of the mixture, preventing the formation of lumps or clumps of particles. The mixed liquid tends to become viscous. When the viscosity is good and the mixture still has fluidity, heating and stirring are stopped.

[0059] Step 5: Once the temperature has cooled to room temperature, seal and store the prepared mixture for later use.

[0060] It is worth noting that, as one of the most prominent substantive features of this invention and one of the significant advancements it brings to the prior art, the optimal conditions for synthesizing pressure-sensitive materials are obtained through experimental simulation, specifically including:

[0061] (1) Effect of temperature

[0062] At room temperature, the mixing reaction of adhesive materials, foaming materials, pressure-sensitive color-changing materials and molding agents is not good and the uniformity is poor. As the temperature increases, the reaction rate increases and the reaction products tend to be more uniform. However, if the temperature is too high, the viscosity of the material will decrease and the material will become brittle. The optimal reaction temperature is 70±2℃. After the reaction is completed, the material should be cooled and sealed for storage.

[0063] (2) Effect of pH value

[0064] When the pH value is greater than 9, the reaction rate is faster, the mixture quickly clumps together, and the uniformity, viscosity, and color change properties are all poor. When the pH value is less than 4, the reaction rate is slower, obvious particles appear in the mixture, and the reaction may even fail to proceed. The optimal pH value for the reaction is 6-8.

[0065] (3) Modification of polyvinyl acetate solution

[0066] When commercially available polyvinyl acetate solution is used to make pressure-sensitive materials, the resulting pressure-sensitive materials are prone to breakage after being coated on the equipment surface. They also have poor heat resistance and water resistance, and are easily broken when the pressure of leaked gas is high. Therefore, it is necessary to modify the polyvinyl acetate solution to improve its toughness and environmental adaptability.

[0067] (4) The content of each reactant added

[0068] Adhesive material (polyvinyl acetate solution) is the main reagent, and its addition should account for 70% to 80% of the final synthetic product; the pressure-sensitive color-changing material (tetraphenyl-imidazolium derivative) should account for about 10%. Too high a content will affect the material's viscosity and foaming properties, while too low a content will result in indistinct color change; the foaming material should be no less than 5% of the total amount. A higher content makes it easier to foam, but the material's toughness will decrease and it will be more prone to breakage. A lower content makes it less sensitive to low-content sulfur hexafluoride leakage.

[0069] (5) The order in which the various reactants are added

[0070] The pressure-sensitive color-changing material (tetraphenyl-imidazolium derivative) should be mixed evenly with the modified adhesive material (polyvinyl acetate solution) first. If it is added after the reaction, it is difficult to mix evenly. The foaming material (sodium alkylbenzene sulfonate) should be added before the molding agent. If the molding agent is added first, the mixture is prone to lumps and reduced viscosity.

[0071] Understandably, as a prominent substantive feature of this invention and a significant advancement over existing technology, when a leak occurs in the equipment, the sulfur hexafluoride leaks out, causing the pressure-sensitive material to blister and deform, making it easily detectable. Furthermore, the pressure-sensitive material also changes color when pressure changes, that is, it changes color simultaneously with blistering, allowing maintenance personnel to observe leaks more quickly.

[0072] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for visually identifying a leakage of an insulating gas, characterized in that, Includes the following steps: A pressure-sensitive material is applied to the surface of an inflation device that uses an insulating gas. The pressure-sensitive material has a set toughness and ductility and changes color after deformation. When the pressure-sensitive material bulged and discolored from the surface of the inflation device, a sulfur hexafluoride leak was visually detected and immediately addressed.

2. The method for visually identifying insulating gas leakage according to claim 1, characterized in that: The insulating gas is sulfur hexafluoride or a mixture of sulfur hexafluoride and nitrogen.

3. The method for visually identifying insulating gas leaks according to claim 1, characterized in that: The pressure-sensitive material is adhesive and is adhered to the surface of the inflation device. After adhesion, it fits the inflation device seamlessly. Alternatively, the pressure-sensitive material can also be a coating material, which is sprayed onto the surface of the inflation device and dries rapidly upon contact with air to become a thin film covering the surface of the device, adhering tightly to the device without gaps.

4. A method for visually identifying insulating gas leaks according to any one of claims 1 to 3, characterized in that: After a leak occurs, the bulging and discolored part is recovered, and the insulating gas inside the bulge is collected to prevent it from being released into the atmosphere. At the same time, the leak point of the inflation equipment is dealt with in a timely manner to prevent further leakage.

5. A pressure sensitive material for insulating gas leakage detection, applied to a visual identification method of insulating gas leakage according to any one of claims 1 to 4, characterized in that, The pressure-sensitive material comprises: adhesive materials, foaming materials, pressure-sensitive color-changing materials, and molding agents; Adhesive materials should account for 70% to 80% of the total mass; pressure-sensitive color-changing materials should account for 8% to 12% of the total mass; and foaming materials should account for no less than 5% of the total mass.

6. A pressure-sensitive material for detecting insulating gas leaks according to claim 5, characterized in that: The adhesive material is an ethyl acetate compound, the foaming material is a surfactant, and the pressure-sensitive color-changing material is a fluorane lactone compound, a methanephthalein compound, or a tetraphenylethylene derivative.

7. A pressure-sensitive material for detecting insulating gas leaks according to claim 5 or 6, characterized in that: The adhesive material is polyvinyl acetate emulsion, the foaming material is sodium alkylbenzene sulfonate, and the pressure-sensitive color-changing material is crystal violet lactone, tetraphenylethylene-imidazolium derivative, or tetraphenylethylene-quinoline derivative.

8. A method for preparing a pressure sensitive material for insulation gas leak detection, characterized by, Includes the following steps: Step 1: Weigh the set mass of adhesive material, place it in the reaction vessel, add a stir bar, and heat to the set temperature; Step 2: Maintain the reaction temperature, add the set mass of pressure-sensitive color-changing material to the adhesive material until it is completely dissolved and homogeneous; Step 3: Add the set amount of foaming material to the mixture prepared in Step 2, and stir until well mixed; Step 4: Add the molding agent to the mixture prepared in Step 3 and stir continuously to keep the mixture homogeneous and prevent lumps or granules from forming. Step 5: Once the temperature has cooled to room temperature, seal and store the prepared mixture for later use.

9. A method for preparing a varistor material for detecting insulating gas leaks according to claim 8, characterized in that: In step 1, weigh 10m of polyvinyl acetate solution and place it in a reaction vessel. Add a stir bar and heat to about 70°C. While stirring, add a small amount of polyvinyl alcohol, polyvinyl formal, potassium persulfate, and starch to modify the polyvinyl acetate solution and improve its toughness and temperature adaptability.

10. A method for preparing a pressure-sensitive material for detecting insulating gas leaks according to claim 8 or 9, characterized in that: In step 2, the reaction temperature is maintained at 70℃±2℃. Approximately m parts of tetraphenylethylene-imidazolium derivative are added to the modified polyvinyl acetate solution in multiple portions until completely dissolved and homogeneous.

11. A method for preparing a pressure-sensitive material for detecting insulating gas leaks according to claim 8 or 9, characterized in that: In step 3, the pH value is adjusted to be close to neutral, and 0.5 m~m of sodium alkylbenzene sulfonate is added to the mixed liquid mixture and stirred until homogeneous.

12. A method for preparing a pressure-sensitive material for detecting insulating gas leaks according to claim 8 or 9, characterized in that: In step 4, the molding agent is added dropwise to the mixed liquid substance in small amounts several times, while stirring continuously to keep the mixture in a uniform state and prevent the formation of lumps or particles. The mixed liquid tends to become viscous. When the viscosity is good and the mixture is still fluid, heating and stirring are stopped.

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