Oil extraction method for waste oil-immersed transformers

Abstract

The present invention discloses an oil extraction method for a waste oil-immersed transformer, which belongs to the field of environmental protection technology. The method comprises an oil pillow extraction process, a high-voltage bushing extraction process and an oil tank extraction process. The oil is sealed and extracted from the oil pillow, the high-voltage bushing and the oil tank in sequence through an oil extraction pipeline connected to an oil extraction pump. The oil extraction method adopted by the present invention can efficiently and quickly extract the waste oil from the oil pillow, the high-voltage bushing and the oil tank of the oil-immersed transformer, and can drain the oil without lifting equipment or an oil drain valve, thereby avoiding oil leakage when draining the oil-immersed transformer, thereby improving work efficiency and saving time and labor costs.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection, and relates to a method for treating and disposing liquid waste, in particular to an oil extraction method suitable for waste oil-immersed transformers. Background Art

[0002] Oil-immersed transformers are widely used in power supply and distribution systems currently undergoing grid renovations in urban and rural areas, as well as industrial and mining enterprises. Using oil as its primary insulation and cooling medium, oil-immersed transformers are a new type of high-performance transformer with a more rational structure and superior performance. Their main components include the core, windings, oil tank, oil pillow, breather, explosion-proof pipe, radiator, insulating sleeve, tap changer, gas relay, thermometer, and oil purifier.

[0003] Scrapped oil-immersed transformers require the waste oil in their tanks to be drained before recycling. In existing technology, the transformer is usually first transported to an oil drain tank or platform via a crane, and then the valve at the oil drain port at the bottom of the transformer is opened to drain the oil. Because the transformer contains a large amount of oil, opening the drain port valve can easily cause waste oil to spray out and leak, contaminating the transformer's outer surface. This method is also inefficient and costly, requiring a larger area to drain the waste oil from the transformer. The oil at the bottom of the transformer cannot be completely dumped, resulting in incomplete draining and residual waste oil inside the transformer, ultimately affecting the harmless disposal and recycling of the transformer. Summary of the Invention

[0004] The purpose of the present invention is to overcome the technical problems of low efficiency and high cost in the oil-immersed transformer oil draining process in the prior art, incomplete oil drainage, and residual waste oil in the oil-immersed transformer, and to provide an oil extraction method suitable for waste oil-immersed transformers, which has high efficiency and low cost, can completely extract the waste oil inside the oil-immersed transformer and avoid the occurrence of waste oil residue.

[0005] In order to solve the above technical problems, the present invention provides a method for extracting oil from a waste oil-immersed transformer, the oil extraction method comprising the following steps:

[0006] Step 1: During the oil pillow oil pumping process, connect the oil outlet of the oil pumping pipe 1 to the oil pump, unscrew the nut on the oil filling port of the oil pillow, and extend the oil inlet end of the oil pumping pipe 1 from the oil filling port into the connection at the bottom of the oil pillow near the oil tank inlet, and pump oil until the waste oil in the oil pillow is emptied;

[0007] Step 2: During the high-pressure casing oil pumping process, unscrew the nut at the top of the high-pressure casing, convert the oil pumping pipeline 1 in step 1 into the oil pumping pipeline 2, and connect the oil outlet of the oil pumping pipeline 2 to the oil pump. Install a pipe joint or elbow at the oil inlet of the oil pumping pipeline 2, align it with the gap of the conductive rod at the top of the high-pressure casing, and perform sealed oil pumping until the waste oil in each high-pressure casing is emptied;

[0008] Step 3: During the oil tank pumping process, unscrew the nut on one of the high-pressure casing clamps, take out the high-pressure casing, convert the oil pumping pipe 2 in step 2 into the oil pumping pipe 3, and connect the oil outlet end of the oil pumping pipe 3 to the oil pump. The oil inlet end of the oil pumping pipe 3 is tilted from the oil inlet of the oil tank to the bottom of the oil tank to pump oil until the waste oil in the tank is emptied.

[0009] As a further improvement measure of the present invention, three high-voltage bushings are arranged side by side on the oil-immersed transformer, and the high-voltage bushing taken out in step three is located at the leftmost end or the rightmost end.

[0010] As a further improvement measure of the present invention, the oil extraction pipe 1 described in the above step 1 is provided with an oil leakage-proof sealing gasket 1. During the oil extraction process of the oil pillow, the oil leakage-proof sealing gasket 1 contacts and fits with the oil filling port.

[0011] As a further improvement measure of the present invention, the inner diameter of the oil extraction pipeline 1 in the above step 1 is set to 10-25 mm.

[0012] As a further improvement measure of the present invention, a second oil-leakage-proof sealing gasket is provided at the gap of the conductive rod at the top of the high-voltage bushing in the above step 2.

[0013] As a further improvement measure of the present invention, in the above step 2, the inner diameter of the oil extraction pipeline 2 is set to 25-32 mm.

[0014] As a further improvement measure of the present invention, the inner diameter of the oil extraction pipeline 3 in the above step 3 is set to 15-25 mm.

[0015] As a further improvement measure of the present invention, the above-mentioned oil extraction pipeline 1 is set to be an aluminum-plastic pipe, a hot water pipe, a PVC pipe or a galvanized pipe, the above-mentioned oil extraction pipeline 2 is set to be a steel wire pipe, a hot water pipe, an aluminum-plastic pipe, a PVC pipe or a galvanized pipe, and the above-mentioned oil extraction pipeline 3 is set to be an aluminum-plastic pipe, a cold water pipe, a hot water pipe, a PVC pipe or a galvanized pipe.

[0016] As a further improvement measure of the present invention, the above-mentioned oil extraction pipeline 1 is set as an aluminum-plastic pipe, the above-mentioned oil extraction pipeline 2 is set as a steel wire pipe, and the above-mentioned oil extraction pipeline 3 is set as a cold water pipe.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. The oil extraction method adopted by the present invention can avoid the leakage of waste oil when the oil-immersed transformer is drained, thereby preventing environmental pollution caused by oil drainage; 2. The oil extraction pipeline in the present invention can extend into the interior of the oil pillow, high-voltage bushing and oil tank, which is more thorough than the oil drainage method in the prior art and avoids the residue of waste oil in the oil-immersed transformer; 3. The present invention does not require a lifting machine to lift the oil-immersed transformer, nor does it require an oil drain tank or an oil drain platform to complete the oil drainage of the oil-immersed transformer, thereby avoiding safety hazards, and the oil extraction speed is 2 to 3 times higher than the oil drainage speed in the prior art, which is conducive to improving work efficiency and saving time and labor costs. DETAILED DESCRIPTION

[0018] The present invention will be further described below.

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail in the following examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] On the contrary, the present invention covers any alternatives, modifications, equivalents, and solutions that fall within the spirit and scope of the present invention as defined by the claims. Furthermore, to facilitate a better understanding of the present invention, certain specific details are described in detail below in the detailed description of the present invention. Those skilled in the art will be able to fully understand the present invention without these details.

[0021] A method for extracting oil from a used oil-immersed transformer includes the following steps: First, extract the waste oil from the oil pillow. An oil extraction pipe with an inner diameter of 20mm or 25mm is selected, or a 4- or 6-inch adapter is installed at the oil inlet of the oil extraction pipe. The oil outlet of the oil extraction pipe is connected to the oil pump, and a leak-proof sealing gasket is installed on the oil extraction pipe. The nut on the oil pillow's oil filling port is unscrewed, and the oil inlet of the oil extraction pipe is extended from the oil filling port to the connection at the bottom of the oil pillow near the oil tank inlet. The oil is then extracted until the waste oil in the oil pillow is completely evacuated. During the oil extraction process, the leak-proof sealing gasket remains in contact with the oil filling port, ensuring a sealed extraction process and effectively improving extraction efficiency. In this embodiment, the oil extraction pipe is made of an aluminum-plastic pipe that can be bent to extract waste oil from various parts of the bottom of the oil pillow. Alternatively, a hot water pipe, PVC pipe, or galvanized pipe may be used.

[0022] Next, extract the waste oil from the high-voltage bushing. Unscrew the nut at the top of the high-voltage bushing, remove the sealing gasket on the high-voltage bushing, and replace it with a second oil-leakage-proof sealing gasket. Convert the first oil extraction pipeline into a second oil extraction pipeline with an inner diameter of 25mm or 32mm, that is, use a 1-inch or 1.2-inch oil extraction pipeline. Connect the oil outlet of the second oil extraction pipeline to the oil pump, and install a pipe joint or elbow at the oil inlet of the second oil extraction pipeline. Align it with the gap between the conductive rods at the top of the high-voltage bushing to seal and extract the oil until the waste oil in each high-voltage bushing is completely evacuated. In this embodiment, the second oil extraction pipeline is made of steel wire pipe, which can be bent to extract the waste oil from various parts of the bottom end of the high-voltage bushing. As other solutions, hot water pipes, aluminum-plastic pipes, PVC pipes, or galvanized pipes can also be used.

[0023] Finally, the waste oil in the oil tank is extracted. Three high-voltage bushings are arranged side by side on the oil-immersed transformer. The high-voltage bushing located at the far left or right end has the largest gap with the oil tank, facilitating the insertion of the oil extraction pipe. Therefore, unscrew the nut on the high-voltage bushing clamp located at the far left or right end of the oil-immersed transformer, remove the high-voltage bushing, and convert the oil extraction pipe 2 into the oil extraction pipe 3 with an inner diameter of 15mm or 25mm. Connect the oil outlet of the oil extraction pipe 3 to the oil pump, and extend the oil inlet of the oil extraction pipe 3 from the oil inlet of the oil tank at an angle to the bottom of the oil tank to extract oil until the waste oil in the oil tank is emptied. In this embodiment, the oil extraction pipe 3 is made of a cold water pipe; as other options, hot water pipes, PVC pipes, or galvanized pipes can also be used.

[0024] Since the lowest level of waste oil in the oil pillow is higher than the highest level of waste oil in the high-pressure bushing, it is necessary to evacuate the waste oil in the oil pillow first. In this way, when the high-pressure bushing is opened, waste oil leakage will not occur, causing pollution problems. Similarly, since the lowest level of waste oil in the high-pressure bushing is higher than the highest level of waste oil in the oil tank, it is necessary to evacuate the waste oil in the high-pressure bushing first. In this way, when the high-pressure bushing is disassembled, waste oil leakage will not occur, causing pollution problems.

[0025] The above describes the embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. For ordinary technicians in this field, several modifications and improvements can be made without departing from the present invention, and these should also be considered to fall within the scope of protection of the present invention.

Claims

1. A method for extracting oil from a waste oil-immersed transformer, characterized in that: The oil pumping method comprises the following steps: Step 1: During the oil pillow pumping process, connect the oil outlet of the first oil pumping pipe to the oil pump, unscrew the nut on the oil pillow filling port, and extend the oil inlet of the first oil pumping pipe from the filling port into the connection at the bottom of the oil pillow near the oil tank inlet. Pump oil until the waste oil in the oil pillow is emptied. The first oil pumping pipe is equipped with an oil leak-proof sealing gasket. During the oil pillow pumping process, the oil leak-proof sealing gasket is in contact with the filling port. The inner diameter of the first oil pumping pipe is set to 10-25mm. Step 2: During the high-pressure casing oil pumping process, unscrew the nut at the top of the high-pressure casing, convert the oil pumping pipe 1 in step 1 into the oil pumping pipe 2, and connect the oil outlet of the oil pumping pipe 2 to the oil pump. Install a pipe joint or elbow at the oil inlet of the oil pumping pipe 2, align it with the gap between the conductive rods at the top of the high-pressure casing, and perform sealed oil pumping until the waste oil in each high-pressure casing is completely pumped out. Install a second oil-leakage-proof sealing gasket at the gap between the conductive rods at the top of the high-pressure casing. The inner diameter of the oil pumping pipe 2 is set to 25-32mm. Step 3: During the oil tank pumping process, unscrew the nut on one of the high-pressure casing clamps, take out the high-pressure casing, convert the oil pumping pipe 2 in step 2 into the oil pumping pipe 3, and connect the oil outlet of the oil pumping pipe 3 to the oil pump. The oil inlet of the oil pumping pipe 3 is tilted from the oil inlet of the oil tank to the bottom of the oil tank to pump oil until the waste oil in the tank is emptied. The inner diameter of the oil pumping pipe 3 is set to 15~25mm.

2. The method for extracting oil from a waste oil-immersed transformer according to claim 1, characterized in that: There are three high-voltage bushings arranged side by side on the oil-immersed transformer. The high-voltage bushing taken out in step 3 is located at the leftmost or rightmost end.

3. The method for extracting oil from a waste oil-immersed transformer according to claim 1, characterized in that: The oil extraction pipeline 1 is set to be an aluminum-plastic pipe, a hot water pipe, a PVC pipe or a galvanized pipe, the oil extraction pipeline 2 is set to be a steel wire pipe, a hot water pipe, an aluminum-plastic pipe, a PVC pipe or a galvanized pipe, and the oil extraction pipeline 3 is set to be an aluminum-plastic pipe, a cold water pipe, a hot water pipe, a PVC pipe or a galvanized pipe.

4. The method for extracting oil from a waste oil-immersed transformer according to claim 3, characterized in that: The first oil extraction pipeline is configured as an aluminum-plastic pipe, the second oil extraction pipeline is configured as a steel wire pipe, and the third oil extraction pipeline is configured as a cold water pipe.