Transformer bushing vacuum oil changing device and oil changing method

Abstract

A transformer bushing vacuum oil-changing device and oil-changing method, belonging to the field of transformer oil-changing technology and equipment. In order to solve the problem that the traditional transformer oil-changing method is cumbersome and consumes a lot of manpower, and the oil-changing cost is high and is not conducive to sustainable development, the present invention provides a transformer bushing vacuum oil-changing device and oil-changing method, which changes the traditional transformer oil-changing mode. Only one person is needed to complete the oil-changing work, which greatly improves the oil-changing efficiency and reduces the oil-changing cost. The use of an integrated vacuum pump to change the transformer oil fills the technical gap of "single-person oil changing" in this field, which is of great significance to the development of the transformer oil-changing field. At the same time, the device has a simple structure and a low manufacturing cost, and is suitable for widespread promotion and use.

Description

Technical Field

[0001] The invention belongs to the technical equipment field of transformer oil change, and particularly relates to a transformer bushing vacuum oil change device and an oil change method. Background Art

[0002] Currently, during work, when it is found during a major overhaul or routine test of a transformer that the insulation resistance of the bushing drops significantly, the dielectric loss increases, and the content of acidic gases such as CH4, C2H4, and C2H6 in the oil sample increases, it indicates that the bushing has shown an increase in the content of insulating oil impurities, a decrease in the withstand voltage strength, and an accelerated aging phenomenon of the bushing. In the face of the above situation, at the technical level, the substation maintenance specialty needs to perform vacuum oil change on the primary bushing of the transformer to reduce the chance of the bushing getting damp, improve the insulation performance of the bushing, delay the aging process of the bushing, and extend its service life. Completing the oil change operation of one-phase bushing in the traditional way requires three maintenance personnel to cooperate (excluding full-time guardians). Before the oil change, the bushing is erected and fixed first. After the vacuum oil filter, vacuum pump, and qualified transformer oil are ready, the three operators are respectively responsible for controlling the valve of the small oil tank at the upper end of the bushing, the drain plug valve at the lower end of the bushing, and the vacuum pump switch button according to the division of labor. Only by correctly controlling the opening and closing sequence of the valves at each part of the bushing can the oil discharge, vacuum pumping, oil injection, repeated flushing and other oil change operations of the bushing be realized. This kind of oil change method has a cumbersome process and consumes a large amount of manpower, and the oil change cost is relatively high, which is not conducive to sustainable development. Therefore, it is very practical to develop a transformer bushing vacuum oil change device and an oil change method to solve the above disadvantages. Summary of the Invention

[0003] The invention aims to solve the problems that the traditional transformer oil change method has a cumbersome process, consumes a large amount of manpower, and the oil change cost is relatively high, which is not conducive to sustainable development, and further provides a transformer bushing vacuum oil change device and an oil change method;

[0004] A transformer bushing vacuum oil change device, the device includes a first three-way valve, a second three-way valve, an integrated vacuum pump, a waste oil barrel, and a clean oil barrel;

[0005] The integrated vacuum pump is provided with a waste oil barrel connection end, an upper oil flow end, and a lower oil flow end;

[0006] The first three-way valve is provided with a first connection end, a second connection end, and a third connection end;

[0007] The second three-way valve is provided with a fourth connection end, a fifth connection end, and a sixth connection end;

[0008] The first connection end is connected to the upper oil port in the casing through a conduit, the second connection end is connected to the upper oil passage end in the integrated vacuum pump through a conduit, the third connection end is connected to the outside air, the fourth connection end is connected to the lower oil port in the casing through a conduit, the fifth connection end is connected to the lower oil passage end in the integrated vacuum pump through a conduit, the sixth connection end is connected to the oil outlet end of the clean oil barrel through a conduit, and the waste oil barrel connection end on the integrated vacuum pump is connected to the upper oil port of the waste oil barrel through a conduit;

[0009] Further, the integrated vacuum pump is composed of a vacuum pump and a filter oil pump combined;

[0010] A method for vacuum oil change of a transformer casing, the method is realized through the following steps:

[0011] Step 1: Drain the dirty oil inside the casing into the waste oil barrel; close the second connection end on the first three-way valve, keep the first connection end and the third connection end open and connected to the air. After the air flows into the casing, close the sixth connection end on the second three-way valve, keep the fourth connection end and the fifth connection end open, so that the lower oil port is connected to the integrated vacuum pump. By the principle of generating negative pressure through the vacuum pumping of the integrated vacuum pump, help the dirty oil inside the casing to be quickly and cleanly drained into the waste oil barrel;

[0012] Step 2: After the casing oil is emptied, perform vacuum pumping; close the fourth connection end, the fifth connection end and the sixth connection end on the second three-way valve to disconnect the lower oil port from the integrated vacuum pump. Open the first connection end and the second connection end on the first three-way valve and close the third connection end to connect the upper oil port to the integrated vacuum pump, and start the vacuum pumping function of the integrated vacuum pump to complete the casing vacuum pumping step;

[0013] Step 3: Clean oil enters the casing; in a vacuum environment of the casing, close the first connection end, the second connection end and the third connection end on the first three-way valve to disconnect the upper oil port from the integrated vacuum pump. Open the fourth connection end and the sixth connection end on the second three-way valve and close the fifth connection end to connect the lower oil port below to the clean oil barrel. Through the principle of atmospheric pressure, pump the clean oil into the casing through the lower oil port;

[0014] Step 4: Flush the inside of the casing: Repeat the above steps 1 to 3 for 2 - 3 times;

[0015] Step 5: Inject clean oil into the cleaned casing; repeat Step 3 to inject clean oil into the casing. After checking whether the oil level meets the standard according to the oil level gauge requirements, open the first connection end and the third connection end on the first three-way valve to allow air to enter the casing. After the air and oil inside the casing reach the standard 1 atmospheric pressure, then close the first connection end, the second connection end and the third connection end on the first three-way valve;

[0016] Step 6: Disconnect the casing from the first three-way valve and the second three-way valve. After sealing both the upper oil port and the lower oil port on the casing, leave the casing stationary for 24 hours. Then, the professional test operators will conduct pre-commissioning tests on the casing, specifically including insulation resistance, dielectric loss, micro water in oil, and oil breakdown voltage tests. The casing can be put into operation only after all test data meet the standards.

[0017] The present invention has the following beneficial effects compared with the prior art:

[0018] A transformer casing vacuum oil change device and an oil change method provided by the present invention change the traditional transformer oil change mode. Only one person is required to complete the oil change work, which greatly improves the oil change efficiency and reduces the oil change cost. Using an integrated vacuum pump to change the oil of the transformer fills the technical gap of "single-person oil change" in this field, which is of great significance for the development of the transformer oil change field. At the same time, the device has a simple structure and low manufacturing cost, and is suitable for widespread promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic connection diagram of the device of the present invention:

[0020] In the figure, 1 is the casing, 2 is the upper oil port, 3 is the lower oil port, 4 is the integrated vacuum pump, a is the first connection end, b is the second connection end, c is the third connection end, d is the fourth connection end, e is the fifth connection end, f is the sixth connection end, 5 is the waste oil barrel, and 6 is the clean oil barrel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Detailed Embodiment 1: Refer to Figure 1 To describe this embodiment, this embodiment provides a transformer casing vacuum oil change device, which includes a first three-way valve, a second three-way valve, an integrated vacuum pump 4, a waste oil barrel 5, and a clean oil barrel 6;

[0022] The integrated vacuum pump 4 is provided with a waste oil barrel connection end, an upper oil flow end, and a lower oil flow end;

[0023] The first three-way valve is provided with a first connection end a, a second connection end b, and a third connection end c;

[0024] The second three-way valve is provided with a fourth connection end d, a fifth connection end e, and a sixth connection end f;

[0025] The first connection end a is connected to the upper oil port 2 in the casing 1 through a conduit. The second connection end b is connected to the upper oil passage end in the integrated vacuum pump 4 through a conduit. The third connection end c is connected to the external air. The fourth connection end d is connected to the lower oil port 3 in the casing 1 through a conduit. The fifth connection end e is connected to the lower oil passage end in the integrated vacuum pump 4 through a conduit. The sixth connection end f is connected to the oil outlet end of the clean oil barrel 6 through a conduit. The waste oil barrel connection end on the integrated vacuum pump 4 is connected to the upper oil port of the waste oil barrel 5 through a conduit.

[0026] Specific Embodiment 2: Refer to Figure 1 To describe this embodiment, this embodiment further defines the integrated vacuum pump 4 described in Specific Embodiment 1. In this embodiment, the integrated vacuum pump 4 is composed of a vacuum pump and a filter oil pump. Other components and connection methods are the same as those in Specific Embodiment 1.

[0027] Specific Embodiment 3: Refer to Figure 1 To describe this embodiment, this embodiment provides a method for vacuum oil change of a transformer casing. The method is achieved through the following steps:

[0028] Step 1: Drain the dirty oil inside the casing into the waste oil barrel; close the second connection end b on the first three-way valve, open the first connection end a and the third connection end c to connect with the air. After the air flows into the casing 1, close the sixth connection end f on the second three-way valve, open the fourth connection end d and the fifth connection end e, so that the lower oil port 3 is connected to the integrated vacuum pump 4. By the principle of generating negative pressure through the vacuum pumping of the integrated vacuum pump 4, help the dirty oil inside the casing 1 be quickly and cleanly drained into the waste oil barrel 5.

[0029] Step 2: Perform vacuum pumping after the casing oil is emptied; close the fourth connection end d, the fifth connection end e, and the sixth connection end f on the second three-way valve to disconnect the lower oil port 3 from the integrated vacuum pump 4. Open the first connection end a and the second connection end b on the first three-way valve and close the third connection end c to connect the upper oil port 2 to the integrated vacuum pump 4. Start the vacuum pumping function of the integrated vacuum pump 4 to complete the vacuum pumping step of the casing 1.

[0030] Step 3: Clean oil enters the casing; in a vacuum environment of the casing, close the first connection end a, the second connection end b, and the third connection end c on the first three-way valve to disconnect the upper oil port 2 from the integrated vacuum pump 4. Open the fourth connection end d and the sixth connection end f on the second three-way valve and close the fifth connection end e to connect the lower oil port 3 below to the clean oil barrel 6. Through the principle of atmospheric pressure, pump the clean oil into the casing 1 through the lower oil port 3.

[0031] Step 4: Flush the inside of the casing: Repeat the above Steps 1 to 3 two to three times.

[0032] Step 5: Inject clean oil into the cleaned casing; repeat Step 3 to inject the clean oil into the casing 1, and after checking whether the oil level meets the standard according to the requirements of the oil level gauge, open the first connection end a and the third connection end c on the first three-way valve to allow air to enter the casing 1. After the air and oil inside the casing 1 both reach the standard atmospheric pressure of 1 atm, then close the first connection end a, the second connection end b, and the third connection end c on the first three-way valve;

[0033] Step 6: Disconnect the casing 1 from the first three-way valve and the second three-way valve, and seal both the upper oil port 2 and the lower oil port 3 on the casing 1. After the casing 1 is left stationary for 24 hours, the professional test operators will conduct pre-commissioning tests on the casing 1, specifically including insulation resistance, dielectric loss, micro water in oil, and oil breakdown voltage tests. The casing 1 can be put into operation only when the test data of each item meets the standard.

[0034] In this embodiment, during the oil change process, it also includes a step of flushing the inside of the casing 1 with clean oil, which ensures the purity of the clean oil inside the casing 1 after the oil change. Moreover, the flushing process is also completed by a single person. While avoiding the influence of residual dirty oil on the inside of the casing 1, it also simplifies the cleaning process and reduces the maintenance cost of the transformer.

[0035] The present invention has been disclosed above with preferred embodiments. However, it is not intended to limit the present invention. Any person skilled in the art, without departing from the technical solution of the present invention, can make some changes or modifications to the above-disclosed structure and technical content to form equivalent embodiments of equivalent changes. However, as long as it does not depart from the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A transformer bushing vacuum oil changing method, wherein the oil changing device used in the oil changing method comprises a No. 1 three-way valve, a No. 2 three-way valve, an integrated vacuum pump (4), a waste oil barrel (5) and a clean oil barrel (6); The integrated vacuum pump (4) is provided with a waste oil barrel connection end, an upper oil outlet end and a lower oil outlet end; The No. 1 three-way valve is provided with a No. 1 connection end (a), a No. 2 connection end (b) and a No. 3 connection end (c); The No. 2 three-way valve is provided with a No. 4 connection end (d), a No. 5 connection end (e) and a No. 6 connection end (f); The first connection end (a) is connected to the upper oil port (2) in the casing (1) through a conduit, the second connection end (b) is connected to the upper oil outlet end of the integrated vacuum pump (4) through a conduit, the third connection end (c) is connected to the outside air, the fourth connection end (d) is connected to the lower oil port (3) in the casing (1) through a conduit, the fifth connection end (e) is connected to the lower oil outlet end of the integrated vacuum pump (4) through a conduit, the sixth connection end (f) is connected to the oil outlet end of the clean oil barrel (6) through a conduit, and the waste oil barrel connection end on the integrated vacuum pump (4) is connected to the upper oil port of the waste oil barrel (5) through a conduit; The integrated vacuum pump (4) is composed of a vacuum pump and an oil filter pump; Features: The oil changing method is achieved by the following steps: Step 1: drain the dirty oil inside the casing into a waste oil barrel; close the No. 2 connection end (b) on the No. 1 three-way valve, unblock the No. 1 connection end (a) and the No. 3 connection end (c) to connect with the air, and after the air flows into the casing (1), close the No. 6 connection end (f) on the No. 2 three-way valve, unblock the No. 4 connection end (d) and the No. 5 connection end (e), and connect the lower oil port (3) with the integrated vacuum pump (4). Through the principle of vacuuming and generating negative pressure by the integrated vacuum pump (4), the dirty oil in the casing (1) is helped to be quickly and cleanly discharged into the waste oil barrel (5); Step 2: After the casing oil is emptied, vacuum is evacuated; the No. 4 connection end (d), the No. 5 connection end (e) and the No. 6 connection end (f) on the No. 2 three-way valve are closed to disconnect the lower oil port (3) from the integrated vacuum pump (4); the No. 1 connection end (a) and the No. 2 connection end (b) on the No. 1 three-way valve are opened, and the No. 3 connection end (c) is closed to connect the upper oil port (2) to the integrated vacuum pump (4); the vacuum evacuation function of the integrated vacuum pump (4) is started, and the casing (1) vacuum evacuation step is completed; Step 3: clean oil is introduced into the casing; in a vacuum environment, the casing is closed at the No. 1 three-way valve connecting end (a), the No. 2 connecting end (b) and the No. 3 connecting end (c), so that the upper oil port (2) is disconnected from the integrated vacuum pump (4), the No. 4 connecting end (d) and the No. 6 connecting end (f) on the No. 2 three-way valve are opened, and the No. 5 connecting end (e) is closed, so that the lower oil port (3) below is connected to the clean oil barrel (6), and the clean oil is pumped into the casing (1) through the lower oil port (3) according to the principle of atmospheric pressure; Step 4: Flush the cannula: Repeat steps 1 to 3 2-3 times; Step 5: inject clean oil into the cleaned casing; repeat step 3 to inject clean oil into the casing (1), and check whether the oil level meets the standard according to the oil level gauge, then open the No. 1 connection end (a) and the No. 3 connection end (c) on the No. 1 three-way valve to allow air to enter the casing (1), so that the air and oil inside the casing (1) reach the standard 1 atmosphere pressure, and then close the No. 1 connection end (a), the No. 2 connection end (b) and the No. 3 connection end (c) on the No. 1 three-way valve; Step 6: After the casing (1) is disconnected from the No. 1 three-way valve and the No. 2 three-way valve, and the upper oil port (2) and the lower oil port (3) on the casing (1) are sealed, the casing (1) is left stationary for 24 hours. The testing professional operator will conduct a pre-commissioning test on the casing (1), including insulation resistance, dielectric loss, oil-micro-water and oil withstand voltage tests. The casing can be put into operation only after all test data meet the standards.

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