Purification method of transformer oil

Abstract

The invention provides a purification method of transformer oil, and belongs to the field of electrical equipment maintenance. The invention provides a transformer oil purification method which comprises the following steps: introducing transformer oil into a microporous ceramic filter for filtering, and removing solid particles and macromolecular impurities to obtain first purified oil; mixing the first purified oil with a molecular sieve at normal temperature and normal pressure for adsorption, and removing moisture, oxygen and part of aging products to obtain second purified oil; mixing the second purified oil with an antioxidant, carrying out oxidation reaction, and decomposing the residual aging product to obtain third purified oil; the third purified oil is subjected to centrifugal separation, and purified transformer oil is obtained. Solid particles, macromolecular impurities, moisture, oxygen and aging products in the transformer oil are removed through filtration of the microporous ceramic filter, adsorption of the molecular sieve, oxidation reaction with the antioxidant and centrifugal separation, so that the purified transformer oil reaches the new oil standard.

Description

Technical Field

[0001] This invention relates to the field of power equipment maintenance, and more specifically to a method for purifying transformer oil. Background Technology

[0002] In the power industry, transformer oil serves as an insulating and cooling medium, and its performance directly affects the safe operation and lifespan of transformers. With prolonged use, transformer oil deteriorates due to thermal decomposition, oxidation, and contamination by impurities, leading to a decline in its insulation performance and even causing malfunctions.

[0003] Currently, common methods for purifying transformer oil include filtration, degassing, dehydration, or the addition of antioxidants. However, these methods suffer from high costs and poor purification effects. For example, filtration is insufficient to remove trace amounts of moisture and aging products from the oil; degassing and dehydration processes are complex and require high-temperature or vacuum equipment, resulting in high costs; and the addition of antioxidants can affect the stability of the oil, making it difficult to restore it to near-new oil standards. Summary of the Invention

[0004] This invention provides a method for purifying transformer oil. The purification method of this invention is low in cost, and the purified transformer oil can be restored to the standard of new oil.

[0005] This invention provides a method for purifying transformer oil, comprising the following steps:

[0006] Transformer oil is passed through a microporous ceramic filter to remove solid particles and macromolecular impurities, resulting in the first purified oil.

[0007] At room temperature and pressure, the first purified oil is mixed with molecular sieve for adsorption to remove moisture, oxygen and some aging products, thus obtaining the second purified oil.

[0008] The second purified oil is mixed with an antioxidant to undergo an oxidation reaction, decomposing the remaining aging products to obtain the third purified oil;

[0009] The third purified oil is centrifuged to obtain purified transformer oil.

[0010] Preferably, the pore size of the microporous ceramic filter is 25-50 μm; the filtration accuracy of the microporous ceramic filter is not greater than 0.5 μm.

[0011] Preferably, during filtration, the flow rate of the transformer oil is less than 0.5 mm / s.

[0012] Preferably, the molecular sieve includes a mesoporous molecular sieve, SBA-15.

[0013] Preferably, the mass of the molecular sieve is 3 to 5% of the mass of the first purified oil.

[0014] Preferably, the adsorption temperature is 25-35°C and the time is 60-80 min.

[0015] Preferably, the antioxidant includes phenolic antioxidants.

[0016] Preferably, the phenolic antioxidant includes one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-p-cresol, and 2,6-di-tert-butyl-α-dimethylamino-p-cresol.

[0017] Preferably, the mass ratio of the second purified oil to the antioxidant is 1:0.04 to 0.11.

[0018] Preferably, the oxidation reaction is carried out at a temperature of 40–60°C for a duration of more than 60 min.

[0019] This invention provides a method for purifying transformer oil, comprising the following steps:

[0020] Transformer oil is passed through a microporous ceramic filter to remove solid particles and macromolecular impurities, resulting in the first purified oil.

[0021] At room temperature and pressure, the first purified oil is mixed with molecular sieve for adsorption to remove moisture, oxygen and some aging products, thus obtaining the second purified oil.

[0022] The second purified oil is mixed with an antioxidant to undergo an oxidation reaction, decomposing the remaining aging products to obtain the third purified oil;

[0023] The third purified oil is centrifuged to obtain purified transformer oil.

[0024] The transformer oil undergoes filtration through a microporous ceramic filter, adsorption through molecular sieves, oxidation reaction with antioxidants, and centrifugal separation. This process removes solid particles, large molecular impurities, moisture, oxygen, and aging products from the transformer oil, ensuring that the purified oil meets new oil standards. Furthermore, adsorption does not require a high-temperature or vacuum environment, reducing purification costs. The oxidation reaction with antioxidants removes aging products while reducing the antioxidant content in the transformer oil, thus improving the stability of the purified transformer oil. Attached Figure Description

[0025] Figure 1 This is a process flow diagram for purifying transformer oil, as shown in the example. Detailed Implementation

[0026] This invention provides a method for purifying transformer oil, comprising the following steps:

[0027] Transformer oil is passed through a microporous ceramic filter to remove solid particles and macromolecular impurities, resulting in the first purified oil.

[0028] At room temperature and pressure, the first purified oil is mixed with molecular sieve for adsorption to remove moisture, oxygen and some aging products, thus obtaining the second purified oil.

[0029] The second purified oil is mixed with an antioxidant to undergo an oxidation reaction, decomposing the remaining aging products to obtain the third purified oil;

[0030] The third purified oil is centrifuged to obtain purified transformer oil.

[0031] This invention involves passing transformer oil through a microporous ceramic filter to remove solid particles and macromolecular impurities, thereby obtaining a first purified oil.

[0032] In this invention, the pore size of the microporous ceramic filter is preferably 25-50 μm; in specific embodiments, the pore size can be 25, 30, 40, 45 or 50 μm; the filtration accuracy of the microporous ceramic filter is preferably no greater than 0.5 μm; in specific embodiments, the filtration accuracy can be 0.1, 0.2, 0.3, 0.4 or 0.5 μm.

[0033] In this invention, during filtration, the flow rate of the transformer oil is preferably less than 0.5 mm / s; in specific embodiments, the flow rate can be 0.1, 0.2, 0.3, 0.4 or 0.5 mm / s.

[0034] After obtaining the first purified oil, the present invention mixes the first purified oil with a molecular sieve at room temperature and pressure for adsorption to remove moisture, oxygen and some aging products, thereby obtaining the second purified oil.

[0035] In this invention, the molecular sieve preferably includes a mesoporous molecular sieve SBA-15; the mass of the molecular sieve is preferably 3 to 5% of the mass of the first purified oil. In specific embodiments, the mass of the molecular sieve can be 3%, 4% or 5% of the mass of the first purified oil.

[0036] In this invention, the adsorption temperature is preferably 25-35°C; in specific embodiments, the adsorption temperature can be 25, 28, 30 or 35°C; the time is 60-80 min; in specific embodiments, the adsorption time can be 60, 65, 70, 75 or 80 min.

[0037] After adsorption, the present invention preferably further includes solid-liquid separation to obtain a second purified oil.

[0038] After obtaining the second purified oil, the present invention mixes the second purified oil with an antioxidant to carry out an oxidation reaction, decomposes the remaining aging products, and obtains the third purified oil.

[0039] In this invention, the mass ratio of the second purified oil to the antioxidant is preferably 1:0.04 to 0.11; in specific embodiments, the mass ratio can be 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, or 1:0.11; the antioxidant preferably includes phenolic antioxidants; in specific embodiments, the phenolic antioxidant preferably includes one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-p-cresol, and 2,6-di-tert-butyl-α-dimethylamino-p-cresol.

[0040] In this invention, the temperature of the oxidation reaction is preferably 40-60°C; in specific embodiments, the adsorption temperature can be 40, 45, 50, 55 or 60°C; the time is preferably higher than 60 min; in specific embodiments, the adsorption time can be 60, 65, 70, 75 or 80 min.

[0041] In a specific embodiment, the oxidation reaction is carried out under stirring conditions.

[0042] After obtaining the third purified oil, the present invention centrifuges the third purified oil to obtain purified transformer oil.

[0043] In a specific embodiment, the centrifugal separation speed is preferably not less than 5000 r / min; the centrifugal separation time is preferably not less than 5 min. After centrifugation, fine impurities are removed.

[0044] The following detailed description of the transformer oil purification method provided by the present invention, in conjunction with embodiments, should not be construed as limiting the scope of protection of the present invention.

[0045] Figure 1 This is a process flow diagram for purifying transformer oil, as shown in the example.

[0046] Example 1

[0047] (1) Microporous ceramic filtration treatment: A microporous ceramic filter with a pore size of 35μm and a filtration accuracy of 0.5μm was used to perform preliminary filtration of the mineral insulating oil in a 200KVA transformer that had been in use for 5 years (oil flow rate of 0.4mm / s), which effectively removed solid particles and macromolecular impurities in the oil, such as dust, fibers and aged gum.

[0048] (2) Molecular sieve adsorption treatment: Mesoporous molecular sieve SBA-15 was selected to perform deep adsorption treatment and solid-liquid separation on the filtered transformer oil to obtain treated transformer oil. During the adsorption treatment: the mass of mesoporous molecular sieve SBA-15 was 4.5% of the mass of the filtered transformer oil. Under normal temperature conditions, the treatment time was controlled at 75 min. During this process, the molecular sieve effectively adsorbed moisture, oxygen and some polar aging products in the oil, significantly improving the insulation performance of the oil.

[0049] (3) Antioxidant treatment: Add 10 kg of phenolic antioxidant T501 to 100 kg of transformer oil after the above treatment. Stir at 55°C for 65 min to allow the antioxidant to fully react with the aging products in the oil, thereby effectively delaying the further aging of the oil.

[0050] (4) Centrifugal separation and purification: The treated oil is finally purified using a centrifugal oil filter. The speed is set to 5500 r / min and the running time is 6 min. This step thoroughly removes residual micro-impurities, ensuring the purity of the oil and its long-term reliability.

[0051] Implementation effectiveness evaluation:

[0052] 1. After the above processing procedure, the insulation breakdown voltage of this batch of transformer oil increased from 15KV before processing to over 30KV, which is close to the standard of new oil.

[0053] 2. The moisture and oxygen content of the oil have both decreased to below the national standards: the moisture content is below 50 ppm, the oxygen content has decreased to 80 ppm, and the color of the oil has changed from dark yellow to clear and transparent.

[0054] 3. After a year of use and follow-up, it was found that the treated transformer oil significantly reduced equipment wear and failure rate, extended equipment service life and reduced maintenance costs.

[0055] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for purifying transformer oil, characterized in that, Includes the following steps: Transformer oil is passed through a microporous ceramic filter to remove solid particles and macromolecular impurities, resulting in the first purified oil. At room temperature and pressure, the first purified oil is mixed with molecular sieve for adsorption to remove moisture, oxygen and some aging products, thus obtaining the second purified oil. The second purified oil is mixed with an antioxidant to undergo an oxidation reaction, decomposing the remaining aging products to obtain the third purified oil; The third purified oil is centrifuged to obtain purified transformer oil.

2. The purification method according to claim 1, characterized in that, The microporous ceramic filter has a pore size of 25–50 μm and a filtration accuracy of no more than 0.5 μm.

3. The purification method according to claim 1 or 2, characterized in that, During filtration, the flow rate of the transformer oil is less than 0.5 mm / s.

4. The purification method according to claim 1, characterized in that, The molecular sieve includes the mesoporous molecular sieve SBA-15.

5. The purification method according to claim 1 or 4, characterized in that, The mass of the molecular sieve is 3 to 5% of the mass of the first purified oil.

6. The purification method according to claim 1 or 4, characterized in that, The adsorption temperature is 25–35°C, and the time is 60–80 min.

7. The purification method according to claim 1, characterized in that, The antioxidants include phenolic antioxidants.

8. The purification method according to claim 7, characterized in that, The phenolic antioxidants include one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-p-cresol, and 2,6-di-tert-butyl-α-dimethylamino-p-cresol.

9. The purification method according to claim 1, 7, or 8, characterized in that, The mass ratio of the second purified oil to the antioxidant is 1:0.04 to 0.

11.

10. The purification method according to claim 1, characterized in that, The oxidation reaction is carried out at a temperature of 40–60°C for a duration of more than 60 min.

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