Method for effectively removing microorganisms in transformer oil and application
By adding CuO NPs nanofluid materials to the transformer oil, using their physical or chemical adsorption to remove microorganisms, the problem of degradation of insulation performance caused by microorganism growth is solved, and the safety and operating stability of the transformer are significantly improved.
Patent Information
- Application Number
- CN202411327466.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2024-12-27
AI Technical Summary
The growth and reproduction of microorganisms in transformer oil leads to a decrease in insulation level, threatening the safe and stable operation of the transformer, and it is difficult for the existing technology to effectively solve it.
CuO NPs nanofluid material is mixed with transformer oil, and microorganisms are removed by physical adsorption or chemical adsorption. The preparation method of nanofluid material includes stirring CuCl2·2H2O precursor solution and NaOH solution, annealing and grinding to obtain CuO NPs nano The mass fraction of the nanofluid material in oil is 0.05 wt.%-10 wt.%.
Effectively adsorbing and sterilizing microorganisms in transformer oil reduces its impact on insulation performance and provides a solid foundation for transformer fault warning technology.
Abstract
Description
Technical Field
[0001] The invention belongs to the field of transformer fault early warning, and in particular relates to a method for removing microorganisms in transformer oil and an application thereof. Background Art
[0002] The growth and reproduction of microorganisms in transformer oil is an issue that cannot be ignored. These microorganisms use transformer oil as the only carbon source for metabolic activities, and the polar substances and charged colloidal components they produce will significantly affect the electrical properties of transformer oil, and even cause the insulation level to drop, threatening the safe and stable operation of the transformer.
[0003] Therefore, it is particularly important to develop effective methods for microbial removal. Existing studies have shown that copper-based nanoparticles have attracted much attention due to their excellent adsorption and bactericidal abilities. In addition, the use of copper-based nanoparticles is in line with the principles of environmental protection and cost-effectiveness, and is a solution worth promoting. The effective removal of microorganisms in oil not only improves the safety of transformers, but also provides strong support for the stable operation of power systems.
[0004] Therefore, copper-based nanoparticles are urgently needed and applied to the removal of microorganisms in transformer oil to effectively inhibit the growth and reproduction of microorganisms. Summary of the invention
[0005] The technical problem to be solved by the present invention is to overcome the problem that the growth and reproduction of microorganisms in the prior art causes the insulation level to drop, threatening the safe and stable operation of the transformer, and to provide a method for removing microorganisms in transformer oil and its application.
[0006] The present invention adopts the following technical solutions to solve the above technical problems:
[0007] The present invention provides an effective method for removing microorganisms in transformer oil, characterized in that CuO NPs nanofluid material is stirred and mixed in transformer oil, and dispersed;
[0008] Wherein, the mass fraction of the CuO NPs nanofluid material in the transformer oil is 0.05wt.%-10wt.%.
[0009] The present invention also provides a CuO NPs nanofluid material, wherein the preparation method of the CuO NPs nanofluid material comprises the following steps:
[0010] (1) Using ethanol as solvent, add CuCl 2 ·2H 2 O, to obtain CuCl 2 ·2H 2 O precursor solution;
[0011] (2) The CuCl prepared in step (1) 2 ·2H 2 O precursor solution was dropped into NaOH solution and stirred to obtain Cu(OH) 2 ;
[0012] (3) The Cu(OH) obtained in step (2) 2 The CuO NPs nanofluid material is obtained by annealing and grinding.
[0013] In some embodiments, in step (1), the CuCl 2 ·2H 2 The concentration of the O precursor solution is 0.1-0.5 mol / L.
[0014] In some embodiments, step (2) satisfies at least one of the following conditions:
[0015] The concentration of the NaOH solution is 0.1-1 mol / L;
[0016] The dripping rate is 0.1-2.5 mL / min;
[0017] The stirring time is 1-2.5h;
[0018] The stirring speed is 400-700 rpm;
[0019] The CuCl 2 ·2H 2 The volume ratio of the O precursor solution to the NaOH solution is 0.5-4.
[0020] In some embodiments, in step (2), the Cu(OH) 2 The method further comprises at least one of centrifuging, washing and drying.
[0021] In some embodiments, step (2) satisfies at least one of the following conditions:
[0022] The centrifugal speed is 2000-5000rpm;
[0023] The centrifugation time is 5-30min;
[0024] The washing is deionized washing;
[0025] The number of washings is 5-10 times;
[0026] The drying is vacuum drying; wherein, when the drying is vacuum drying, the temperature of the vacuum drying is 50-80° C., and the time of the vacuum drying is 6-15 hours.
[0027] In some embodiments, step (3) satisfies at least one of the following conditions:
[0028] The annealing treatment is carried out at a temperature of 400 to 800°C;
[0029] The grinding is conventional in the art and can be ground into powder.
[0030] In some embodiments, the dispersing is performed under ultrasound;
[0031] The stirring speed is 800-1500 rpm;
[0032] The stirring time is 40 to 220 minutes;
[0033] In some embodiments, the ultrasound duration is 60-120 min;
[0034] The power of the ultrasound is 400-500w.
[0035] The present invention also provides an effective method for removing microorganisms in transformer oil, which is characterized in that the microorganisms in the transformer oil are adsorbed by physical adsorption or chemical adsorption.
[0036] On the basis of conforming to the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present application.
[0037] The reagents and raw materials used in the present invention are commercially available.
[0038] The positive and progressive effects of the present invention are:
[0039] The CuO NPs nanofluid material prepared by the invention has a large specific surface area and unique surface properties, and can interact with microorganisms in a physical adsorption or chemical adsorption manner.
[0040] The effective method for removing microorganisms in transformer oil provided by the present invention can effectively adsorb microorganisms in transformer oil, reduce their influence on insulation performance, and lay a solid foundation for the advancement of transformer fault warning technology. DETAILED DESCRIPTION
[0041] The present application is further described below by way of examples, but the present application is not limited to the scope of the examples. The experimental methods without specific conditions in the following examples are selected according to conventional methods and conditions, or according to the product instructions.
[0042] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0043] The raw materials in the following examples are all commercially available.
[0044] In the following examples, Rothschild was purchased from Wuhan Huizao Biotechnology Co., Ltd.
[0045] Example 1
[0046] (1) Use 50 mL of ethanol as solvent to prepare 0.4 mol / L CuCl 2 ·2H 2 O precursor solution, and stirred at 650 r / min for 2 h, 0.7 mol / L NaOH solution was dropped into CuCl 2 In the solution, during the reaction, the solution color changes from green to cyan to black, and the black precipitate is Cu(OH) 2 After centrifugation at 5000r / min for 30min, the dried Cu(OH) 2 The sample was annealed in a muffle furnace at 600 °C and then ground to obtain CuO NPs nanofluid material.
[0047] (2) Use an inoculation needle to inoculate the cultured Rothschild bacteria (purchased from Wuhan Huizao Biotechnology Co., Ltd.) into fresh transformer oil. The temperature was maintained at 30 °C and the bacterial concentration was maintained at 5 × 10 8 The ground CuONPs were mixed with the transformer oil inoculated with the microorganisms at 5 wt.%, stirred with a magnetic stirrer at 1000 r / min for 120 min, and ultrasonically dispersed at 450 W ultrasonic power for 60 min to achieve uniform distribution of the adsorbent. Another control group was not added with CuO NPs.
[0048] Example 2
[0049] (1) Use 35 mL of ethanol as solvent to prepare 0.1 mol / L CuCl 2 ·2H 2 O precursor solution, and stirred at 450 r / min for 1 h, 0.1 mol / L NaOH solution was dropped into CuCl 2 In the solution, during the reaction, the solution color changes from green to cyan to black, and the black precipitate is Cu(OH) 2 After centrifugation at 3000r / min for 10min, the dried Cu(OH) 2 The sample was annealed in a muffle furnace at 500 °C and then ground to obtain CuO NPs nanofluid material.
[0050] (2) Use an inoculation needle to inoculate the cultured Rothschild bacteria (purchased from Wuhan Huizao Biotechnology Co., Ltd.) into fresh transformer oil. The temperature was maintained at 35°C and the bacterial concentration was maintained at 4 × 10 5 The ground CuONPs were mixed with the transformer oil inoculated with the microorganisms at 3 wt.%, stirred with a magnetic stirrer at 800 r / min for 80 min, and ultrasonically dispersed at an ultrasonic power of 450 W for 80 min to achieve uniform distribution of the adsorbent. Another control group was not added with CuO NPs.
[0051] Example 3
[0052] (1) CuO NPs were prepared by coprecipitation. 20 mL of ethanol was used as solvent to prepare 0.2 mol / L CuCl 2 ·2H 2 O precursor solution, and stirred at a speed of 600 r / min for 2.5 h, 0.5 mol / L NaOH solution was dropped into CuCl 2 In the solution, during the reaction, the solution color changes from green to cyan to black, and the black precipitate is Cu(OH) 2 After centrifugation at 5000r / min for 15min, the dried Cu(OH) 2 The sample was annealed under 600℃ muffle furnace calcination conditions and then ground to obtain CuO NPs nanofluid material.
[0053] (2) Use an inoculation needle to inoculate the cultured Rothschild bacteria (purchased from Wuhan Huizao Biotechnology Co., Ltd.) into fresh transformer oil. The temperature was maintained at 30 °C and the bacterial concentration was maintained at 5 × 10 7 The ground CuONPs were mixed with the transformer oil inoculated with the microorganisms at 3.5wt.%, stirred with a magnetic stirrer at 1000r / min for 90min, and ultrasonically dispersed at 450W ultrasonic power for 75min to achieve uniform distribution of the adsorbent. Another control group did not add CuO NPs.
[0054] Example 4
[0055] (1) CuO NPs were prepared by coprecipitation. 40 mL of ethanol was used as solvent to prepare 0.15 mol / L CuCl 2 ·2H 2 O precursor solution, and stirred at a speed of 550r / min for 2h, 0.6mol / L NaOH solution was dropped into CuCl 2In the solution, during the reaction, the solution color changes from green to cyan to black, and the black precipitate is Cu(OH) 2 After centrifugation at 4000r / min for 25min, the dried Cu(OH) 2 The sample was annealed in a muffle furnace at 400 °C and then ground to obtain CuO NPs nanofluid material.
[0056] (2) Use an inoculation needle to inoculate the cultured Rothschild bacteria (purchased from Wuhan Huizao Biotechnology Co., Ltd.) into fresh transformer oil. The temperature is maintained at 30°C and the bacterial concentration is maintained at 5×10 7 The ground CuO NPs were mixed with the transformer oil inoculated with the microorganisms at 2.5wt.%, stirred with a magnetic stirrer at 1200r / min for 100min, and ultrasonically dispersed at an ultrasonic power of 450W for 90min to achieve uniform distribution of the adsorbent. Another control group was not added with CuONPs, and the rest remained unchanged.
[0057] Example 5
[0058] (1) CuO NPs were prepared by coprecipitation. 30 mL of ethanol was used as solvent to prepare 0.2 mol / L CuCl 2 ·2H 2 O precursor solution, and stirred at a speed of 650r / min for 2.5h, 0.8mol / L NaOH solution was dropped into CuCl 2 In the solution, during the reaction, the solution color changes from green to cyan to black, and the black precipitate is Cu(OH) 2 After centrifugation at 3500r / min for 20min, the dried Cu(OH) 2 The sample was annealed under 600℃ muffle furnace calcination conditions and then ground to obtain CuO NPs nanofluid material.
[0059] (2) Use an inoculation needle to inoculate the cultured Rothschild bacteria (purchased from Wuhan Huizao Biotechnology Co., Ltd.) into fresh transformer oil. The temperature was maintained at 30 °C and the bacterial concentration was maintained at 3 × 10 7 The ground CuONPs were mixed with the transformer oil inoculated with the microorganisms at 3 wt.%, stirred for 60 min with a magnetic stirrer at 1000 r / min, and ultrasonically dispersed for 80 min at an ultrasonic power of 450 W to achieve uniform distribution of the adsorbent. Another control group did not add CuO NPs, and the rest remained unchanged.
[0060] Example 1
[0061] Compared with Example 1, the only difference is that the ground CuO NPs are mixed with the transformer oil inoculated with the above-mentioned microorganisms at 0.05 wt.%, and other conditions are the same as those in Example 1.
[0062] Example 2
[0063] Compared with Example 1, the only difference is that the annealing temperature is 300° C., and other conditions are the same as those in Example 1.
[0064] Comparative Example 3
[0065] Compared with Example 1, in step (2), the transformer oil temperature is maintained at 70° C., and other conditions are the same as those in Example 1.
[0066] Comparative Example 4
[0067] Compared with Example 1, in step (2), no ultrasonic dispersion step is performed.
[0068] Comparative Example 5
[0069] Compared with Example 1, the difference is that CuO NPs are replaced by ZnO NPs, and other conditions are the same as those in Example 1.
[0070] Effect Example 1
[0071] The inoculation experimental conditions of the control group were the same as those of Example 1, except that the synthesis and addition steps of CuO NPs were removed; then the microbial content in the transformer oil in Examples 1 to 5 and Comparative Examples 1 to 5 was determined and allowed to stand for 6 hours, and the microorganisms in the transformer oil were detected by direct counting method and compared with those of the control group. The results are shown in Table 1.
[0072] Table 1
[0073] Compared with the control group, the decrease rate of microbial content (%) Example 1 58.3 Example 2 19.5 Example 3 43.9 Example 4 14.3 Example 5 19.3 Comparative Example 1 3.6 Comparative Example 2 10.3 Comparative Example 3 96 Comparative Example 4 8.3 Comparative Example 5 13.8
[0074] From the results in Table 1, it can be seen that the bactericidal effect of the microbial CuO NPs nanofluid materials provided by Examples 1 to 5 of the present invention is higher than that of Comparative Examples 1 to 5 (the decrease rate of microbial content compared with the control group). It can be seen that the microbial CuO NPs nanofluid materials provided by the present invention have a certain adsorption and bactericidal effect on microorganisms in oil, thereby improving the deterioration of insulation performance to a certain extent, laying a solid foundation for the advancement of transformer fault warning technology.
[0075] Finally, it should be noted that in this application, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.
[0076] Although the present application has been disclosed above through the description of the specific embodiments of the present application, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present application within the spirit and scope of the attached scheme. These modifications, improvements or equivalents should also be considered to be included in the scope of protection claimed in the present application.
Claims
1. A method for effectively removing microorganisms in transformer oil, characterized in that: The CuO NPs nanofluid material is stirred and mixed in transformer oil and dispersed; Wherein, the mass fraction of the CuO NPs nanofluid material in the transformer oil is 0.05wt.%-10wt.%.
2. A method for effectively removing microorganisms in transformer oil as claimed in claim 1, characterized in that: The preparation method of the CuONPs nanofluid material comprises the following steps” (1) using ethanol as a solvent and adding CuCl2·2H2O to obtain a CuCl2·2H2O precursor solution; (2) dropping the CuCl2·2H2O precursor solution prepared in step (1) into a NaOH solution and stirring to obtain Cu(OH)2; (3) The Cu(OH)2 obtained in step (2) is annealed and ground to obtain the CuO NPs nanofluid material.
3. The effective method for removing microorganisms in transformer oil as claimed in claim 2, characterized in that: In step (1), the concentration of the CuCl2·2H2O precursor solution is 0.1 to 0.5 mol / L.
4. The effective method for removing microorganisms in transformer oil as claimed in claim 2, characterized in that: Step (2) satisfies at least one of the following conditions: The concentration of the NaOH solution is 0.1-1 mol / L; The dripping rate is 0.1-2.5 mL / min; The stirring time is 1-2.5h; The stirring speed is 400-700 rpm; The volume ratio of the CuCl2·2H2O precursor solution to the NaOH solution is 0.5-4.
5. The effective method for removing microorganisms in transformer oil as claimed in claim 2, characterized in that: In step (2), the Cu(OH)2 further includes at least one of the operations of centrifugation, washing and drying.
6. The effective method for removing microorganisms in transformer oil according to claim 5, characterized in that: Step (2) satisfies at least one of the following conditions: The centrifugal speed is 2000-5000rpm; The centrifugation time is 5-30min; The washing is deionized washing; The number of washings is 5-10 times; The drying is vacuum drying; wherein, when the drying is vacuum drying, the temperature of the vacuum drying is 50-80° C., and the time of the vacuum drying is 6-15 hours.
7. The effective method for removing microorganisms in transformer oil according to claim 2, characterized in that: Step (3) satisfies at least one of the following conditions: The annealing treatment is carried out at a temperature of 400 to 800°C; The grinding may be grinding into powder.
8. A CuO NPs nanofluid material, characterized in that: The compound is prepared by the preparation method described in any one of claims 2 to 7.
9. The effective method for removing microorganisms in transformer oil according to claim 1, characterized in that: The dispersing is carried out under heating and / or ultrasound; Wherein, the heating dimension is 25-65°C; The ultrasonic time is 60-120 minutes; the ultrasonic power is 400-500w.
10. An effective method for removing microorganisms in transformer oil according to any one of claims 1 to 9, characterized in that: Adsorb microorganisms in transformer oil by physical adsorption or chemical adsorption.