JP2009164627A - Oil extraction system of transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil extraction system which is capable of easily recovering PCB insulating oil from a transformer without secondary contamination due to PCB by a method other than methods of forming an isolated chamber. <P>SOLUTION: An oil extraction system of a transformer comprises a transformer having the PCB insulating oil therein, an oil recovery case 11, and an oil extraction device 3, and a closed circuit is formed by connecting an oil outlet port 6 of the transformer and an inlet port 12 of the oil recovery case through an oil extraction pipe 14 of the oil extraction device and connecting a fluid supply port 7 of the transformer and an exhaust port 13 of the oil recovery case through a gas return pipe 15 of the oil extraction device, and a pump P in the oil extraction pipe is driven to not only recover the PCB insulating oil into the oil recovery case but also recover gas in the closed circuit to the transformer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for removing PCB insulating oil from a transformer containing PCB insulating oil (insulating oil containing PCB).

  As a conventional technique for removing the PCB insulating oil from the transformer and detoxifying it, the transformer is lifted and placed on the tray, and an isolation chamber surrounding the outside of the transformer is formed by using the tray. The pump connected to the vessel is driven to collect PCB insulating oil in the tank, and the PCB scattered around the transformer is collected by the PCB removal device connected to the isolation chamber to discharge harmless air to the outside (Patent Document 1).

  However, this method is troublesome because it is necessary to lift the transformer or form an isolation chamber. Therefore, a technique that can easily collect PCB insulating oil without forming an isolation chamber is desired.

  By the way, it is a simple technique to connect the pump to the transformer and recover the PCB insulating oil from the pump to the tank without forming an isolation chamber. When the PCB insulating oil is recovered in the tank, Air is discharged to the outside, and PCB is mixed in the air, which causes secondary contamination.

Japanese Patent Laying-Open No. 2004-71706 (paragraph numbers 0021 to 0024, FIG. 1)

  The present invention was developed in view of the above circumstances, and its purpose is to easily recover PCB insulating oil from the transformer in a manner other than forming an isolation chamber without causing secondary contamination by PCB. It is to provide an oil removal system capable of

  The invention of claim 1 comprises a transformer containing PCB insulating oil, an oil recovery case, and an oil extraction device, and connects the oil discharge port of the transformer and the input port of the oil recovery case with an oil extraction line of the oil extraction device, By connecting the fluid supply port of the transformer and the exhaust port of the oil recovery case with the gas return line of the oil removal device, a closed circuit is formed, and the PCB insulating oil is formed in the oil recovery case by driving the pump in the oil removal line. The oil removal system for the transformer is characterized in that the gas in the closed circuit is recovered in the transformer.

  Since the PCB insulating oil is collected by forming a closed circuit, PCB is mixed in the gas in the closed circuit, but the gas is collected by the transformer and is not discharged to the outside as it is, so that secondary contamination can be prevented.

  Some transformers are gas-sealed, such as nitrogen, and others do not seal gas. In the case of the gas-sealed type, there are a gas filling port and an oil supply port in the upper part of the transformer, and in the case of the one that does not seal the gas, there is only an oil supply port in the upper part of the transformer. Therefore, the fluid supply port is a concept including not only an oil supply port but also a gas filling port. Gas-sealed transformers originally have internal pressures above atmospheric pressure, so oil recovery cases that collect PCB insulation oil and transformers that collect gas in a closed circuit are subject to internal pressures exceeding atmospheric pressure. . If internal pressure is applied, it may leak due to unforeseen circumstances and cause secondary contamination. It is also desirable to prevent secondary contamination by confirming that no internal pressure is applied even to a transformer that does not seal the gas. Therefore, in order to prevent the occurrence of such secondary contamination, as in the invention of claim 2, the exhaust pipe is branched from the gas return pipe, and the fifth valve and the PCB removing means are provided at the outlet of the exhaust pipe. When the pump is driven, the fifth valve is closed to disable the exhaust line, and when the pump and the oil recovery case are released, the fifth valve is opened to open the exhaust line. It is desirable to do. The PCB removing means may be any means as long as it removes PCB mixed in the gas and discharges clean gas, and an example thereof is a filter having activated carbon.

  If the transformer is large, multiple oil collection cases may be used to collect all PCB insulation oil in one transformer. In this case, if PCB insulation oil accumulates in the oil collection case, it will be empty. Need to be replaced. Further, in order to remove oil from a plurality of transformers, it is necessary to remove the PCB insulating oil from a specific transformer and then replace the connection target of the oil removal device with another transformer. In order to prevent the internal pressure from being efficiently removed from the transformer or the oil recovery case before the replacement, or to prevent the PCB from being released into the atmosphere from the oil removal device at the time of replacement, the oil removal conduit as in the invention of claim 3 Has a solenoid valve on the oil recovery case side of the pump and a sixth valve on the transformer side of the pump. The solenoid valve can be opened and closed in conjunction with the pump operation. It is desirable to have a fourth valve on the transformer side from the branch point to the exhaust pipe and a third valve on the oil recovery case side from the branch point.

  During the oil removal operation, the third, fourth and sixth valves are opened to open the closed circuit. When lowering the internal pressure of the oil recovery case, the solenoid valve is closed and the fifth valve of the exhaust line is opened by stopping the pump, the third valve leading to the oil recovery case is opened, and the fourth valve leading to the transformer Close. When lowering the internal pressure of the transformer, the solenoid valve is closed by closing the pump and the fifth valve of the exhaust pipe is opened, the third valve leading to the oil recovery case is closed, and the fourth valve leading to the transformer is closed. Keep it open. In this way, the PCB can be efficiently recovered from the object (oil recovery case, transformer) that lowers the internal pressure. When replacing the oil recovery case, the third valve is closed in addition to the solenoid valve. When replacing the transformer, the valve closest to the replacement object is closed by closing the fourth and sixth valves. Therefore, it is possible to prevent secondary contamination due to PCB leakage from the oil removal device.

  Further, in order to further prevent the PCB from being released into the atmosphere from the connection place during the above-described replacement work, the place where the transformer and the oil recovery case are connected to the oil removal device as in the invention of claim 4 is provided. It is desirable to use a pipe joint composed of a plug and a socket, and the plug and socket each have a fluid leakage prevention function. Since the plug and the socket have a fluid leakage prevention function, the valve operation that is essential in the invention of claim 3 is not necessarily required when replacing the oil recovery case or the transformer. For example, if the pipe joint is provided on the transformer side with respect to the sixth valve, only the fourth valve is closed when replacing the transformer, and the plug or socket of the pipe joint does not close the sixth valve, It is possible to prevent PCB from leaking from the oil removal device.

  In order to prevent leakage when PCB insulating oil is automatically collected in the oil recovery case, a flow rate setting unit is provided in the control device that controls the operation of the pump, and an amount corresponding to the set value entered in the flow rate setting unit is recovered. Then, it is desirable to automatically stop the pump. However, since there is a possibility that the operator may make a mistake in inputting the set value, it is desirable to have a function for setting parameters other than the flow rate in order to prevent this. Also, when PCB insulation oil collected in one transformer is recovered by using multiple oil recovery cases with the same shape, the flow rate corresponding to the set value cannot always be recovered in the last oil recovery case. Sometimes. In such a case, it is efficient if it can be recovered from another transformer by an amount that is less than the set value. However, when the shortage is set again by the flow rate setting unit, there is a possibility that the operator may make an input error. In such a case, it is desirable to have a function for setting parameters other than the flow rate.

  In order to solve this problem, a control device for controlling the operation of the pump is provided as in the invention of claim 5, and the control device detects the weight of the PCB insulating oil collected in the oil recovery case for each oil recovery case. A weight detection unit, a flow rate detection unit that detects the flow rate of PCB insulating oil sent from the pump to the oil recovery case, a weight setting unit that sets a planned recovery weight to the oil recovery case, and a planned recovery flow rate to the oil recovery case And a determination unit that stops the pump based on the detection results of both the flow rate detection unit and the weight detection unit and the setting values of both the weight setting unit and the flow rate setting unit. It is desirable to stop the pump when the detection result from the flow rate detection unit reaches the recovery scheduled flow rate and when the detection result from the weight detection unit reaches the recovery planned weight.

  The planned recovery weight is a value obtained by multiplying the planned recovery flow rate by the general specific gravity (expected specific gravity) of PCB insulating oil. However, when oil is removed from a used transformer, the degree of dirt on the PCB insulating oil, that is, the expected specific gravity, may vary greatly from transformer to transformer depending on the degree of use and deterioration over time. In such a case, it is necessary to correct the expected specific gravity to the actual specific gravity and recalculate the estimated collection weight. In order to calculate the actual specific gravity, it is necessary to divide the weight of the PCB insulating oil accumulated in the oil recovery case by the flow rate sent to the oil recovery case. In this case, the detection result at the flow rate detection unit is normal. This is a prerequisite. Then, when providing a plurality of judgment criteria for stopping the pump, it is necessary to provide criteria other than the flow rate setting unit. In this case, it is desirable to use the invention according to the sixth aspect. That is, a control device for controlling the operation of the pump is provided. The control device detects the weight of the PCB insulating oil collected in the oil recovery case together with the oil recovery case, and the PCB insulation sent from the pump to the oil recovery case. A flow rate detection unit that detects the flow rate of oil, a liquid level detection unit that detects the level of PCB insulating oil in the oil recovery case, and a specific gravity that sets the expected specific gravity of PCB insulating oil and the expected recovery flow rate. A flow rate setting unit, a weight calculation unit for calculating a planned recovery weight from the expected specific gravity and the planned recovery flow rate, a liquid level height setting unit for setting a planned recovery level of the liquid level in the oil recovery case, and a flow rate detection unit, A weight correction unit that calculates the actual specific gravity of the PCB insulating oil from both detection results of the weight detection unit and recalculates and corrects the planned recovery weight based on the actual specific gravity and the planned recovery flow rate, and a determination unit that stops the pump And consist of When the detection result from the weight detection unit reaches the correction weight by the weight correction unit and when the detection result from the liquid level detection unit reaches the expected recovery height by the liquid level setting unit The pump is stopped.

  If it is invention of Claim 1, since a PCB insulating oil can be collect | recovered only by connecting a transformer, an oil collection | recovery case, and an oil extraction apparatus, collection | recovery work becomes easy. Further, since the PCB insulating oil is recovered from the transformer by forming a closed circuit, secondary contamination by PCB can be prevented. Furthermore, not only the PCB insulation oil is recovered in the oil recovery case by using the oil removal conduit, but the gas in the closed circuit mixed with the PCB is also used by the gas return conduit to the transformer that is the PCB generation source. Therefore, if the oil recovery case and the transformer are sealed after the oil removal operation is completed, the oil recovery case and the transformer can be easily moved to another location. .

  According to the invention of claim 2, if the fifth valve is closed, the exhaust pipe line is disabled, and the closed circuit recovers the PCB insulating oil in the oil recovery case and the PCB mixed gas in the transformer. In addition, if the 5th valve is opened when the pump is stopped, the exhaust line is opened and the gas is discharged from the exhaust line, so that the internal pressure of the oil recovery case and the transformer can be lowered. And transformer damage can be prevented. Moreover, since the PCB mixed in the gas in the closed circuit is removed by the PCB removing means, clean gas is discharged from the exhaust pipe, and secondary contamination can be prevented.

  According to the invention of claim 3, when the internal pressure of the oil recovery case is lowered, the solenoid valve is closed by opening the pump and the fifth valve of the exhaust pipe is opened, and the third valve leading to the oil recovery case is provided. Open and close the 4th valve leading to the transformer. When lowering the internal pressure of the transformer, the solenoid valve is closed by closing the pump and the fifth valve of the exhaust pipe is opened, the third valve leading to the oil recovery case is closed, and the fourth valve leading to the transformer is closed. Keep it open. In this way, the PCB can be efficiently recovered from the object (oil recovery case, transformer) that lowers the internal pressure. When replacing the oil recovery case, the third valve is closed in addition to the solenoid valve. When replacing the transformer, the valve closest to the replacement object is closed by closing the fourth and sixth valves. Therefore, it is possible to prevent secondary contamination due to PCB leakage from the oil removal device.

  According to the invention of claim 4, since a pipe joint comprising a plug and a socket each having a fluid leakage prevention function is used at the connection location, even if the connection is released, the PCB is prevented from being released into the atmosphere. it can.

  If it is invention of Claim 5, since the result of both a weight detection part and a flow volume detection part is utilized, even if an operator mistakenly inputs one set value of a weight setting part and a flow volume setting part, The determination unit can stop the pump using the other set value. Therefore, it is possible to prevent the PCB insulating oil from overflowing from the oil recovery case, and safety is improved. Also, if the oil recovery case is of the same shape, the pump is driven without changing the set values of the weight setting unit and flow rate setting unit even when the oil recovery case is replaced. However, it is possible to prevent the PCB insulating oil from overflowing from the oil recovery case, thereby improving workability. In addition, under the condition that the PCB insulation oil collected in one transformer is collected by using multiple oil collection cases of the same shape, the oil collection case where the PCB insulation oil entered only a small amount below the set value. In addition, when recovering the deficiency from another transformer, if the deficiency is input at the flow rate setting unit, both the flow rate and weight parameters are used. If the set value in the weight setting unit is accurate even if there is a mistake, safety is maintained and workability is improved because only one input point is required.

  In the sixth aspect of the invention, the expected specific gravity of the PCB insulating oil is corrected to the actual specific gravity, and the estimated recovery weight is corrected to reflect the result, so that the accurate accuracy according to the actual contamination condition of the PCB insulating oil is corrected. The planned collection weight can be used as a criterion for determining the pump stop, and the possibility of overflow from the collection planned case when it is not corrected can be eliminated. In addition, safety is improved because the two criteria of recovery weight and expected recovery height are used for stopping the pump.

It is a circuit diagram which shows the oil extraction system of the transformer of this invention. It is an exploded view of the oil removal system of FIG. It is a circuit diagram which shows the oil extraction system of the transformer of another example. FIG. 4 is an exploded view of the oil removal system of FIG. 3.

  As shown in FIGS. 1 and 2, the transformer oil removal system of the present invention includes a transformer 1 containing PCB insulating oil, an oil recovery device 2, and an oil removal device 3, and the oil removal device 3 includes the transformer 1. And the oil recovery device 2 are separately connected via the pipe joint 4, the PCB insulating oil is recovered from the transformer 1 through the oil removal device 3 to the oil recovery device 2, and the PCB insulating oil is recovered by the oil recovery device 2. Accordingly, the gas discharged to the outside of the oil recovery device 2 is returned from the oil recovery device 2 to the transformer 1 via the oil removal device 3.

  The pipe joint 4 includes a male plug and a female socket, and each of the plug and the socket is provided with a fluid leakage preventing function. Therefore, not only when the plug is inserted into the socket and integrated, but also when the plug and the socket are separated, it is not necessary to discharge the PCB insulating oil and the gas contained in the PCB to the outside. Then, by attaching one of the plug and the socket to the oil removal device 3 and the other to the transformer 1 and the oil recovery device 2, the transformer 1 and the oil recovery device 2 are connected to the oil removal device 3.

  In the transformer 1, a transformer body (not shown) is immersed in the PCB insulating oil inside the case 5. An upper portion of the case 5 has an eighth valve V8, and a lower portion of the case 5 has a seventh valve V7. The seventh valve V7 and the eighth valve V8 are attached to the case 5 in advance, and one of a plug and a socket is attached to the oil discharge port 6 of the seventh valve V7 and the fluid supply port 7 of the eighth valve V8.

  In the oil recovery apparatus 2, a tray 10 is placed on a carriage 8 via a load cell as a weight detection unit 9, and a drum can as an oil recovery case 11 is placed on the tray 10. And the pipe as the insertion port 12 protrudes on the drum can 11, and it hangs down to the bottom part in a can. Further, a pipe as an exhaust port 13 protrudes on the drum can. One of the plug and socket of the pipe joint 4 is attached to these two pipes. In order to recover the PCB insulating oil from one transformer 1, it is desirable to use a plurality of oil recovery cases having the same capacity.

  The oil removal device 3 includes an oil removal conduit 14 that guides the PCB insulating oil from the transformer 1 to the oil recovery device 2, a gas return conduit 15 that guides the gas discharged from the oil recovery device 2 to the transformer 1, and a gas return tube An exhaust pipe 16 branched from the path 15 is provided. The oil discharge port 6 of the transformer 1 and the input port 12 of the oil recovery case 11 are connected by the oil extraction line 14 of the oil removal device 3, and the fluid supply port 7 of the transformer 1 and the exhaust port 13 of the oil recovery case 11 are oiled. A closed circuit is formed by connecting through the gas return line 15 of the apparatus 3. Then, the pump P is used to send and recover PCB insulating oil from the transformer 1 through the oil drain line 14 to the oil recovery case 11, while the gas discharged from the oil recovery case 11 is passed through the gas return line 15. It is sent to the transformer 1. Further, the pressure of the transformer 1 and the oil recovery case 11 is released from the exhaust pipe line 16. The oil removal device 3 has the above components mounted on a carriage 17.

  The oil draining pipe 14 has a pump P for sending out PCB insulating oil in the middle of the pump, and the first valve V1, the strainer 18, the flow site 19, the flow switch 20, the flexible tube 21, the first pipe V toward the transformer side from the pump P. 6 valve V6, one of the plug and socket is attached in order. Further, an ultrasonic oil meter as the flow rate detection unit 22, the second valve V2, the electromagnetic valve V0, the flexible tube 23, and one of a plug and a socket are sequentially attached from the pump P of the oil removal conduit 14 toward the oil recovery device. . The pump P uses a magnet pump that rotates the impeller by magnetic force. This pump is driven by a magnet and has a structure in which the motor shaft is housed in the casing, so that no oil leakage occurs outside the casing. By the way, when the motor is arranged outside the casing, the motor shaft is inserted into the casing, and the impeller is attached to the protruding part, the motor shaft penetrates the casing. Occurs. Therefore, secondary contamination can be prevented with a magnet pump. Since the ultrasonic flowmeter 22 is accurate even if some dust (insulating paper, cotton, sludge) enters, the strainer 18 has a 20 mesh mesh. Further, in the gear type flow meter, in order to prevent dust from entering the meshing portion of the gear, a mesh of 60 to 80 mesh is required, and clogging is accelerated and the number of replacements is frequent. This leads to oil contamination at the time of replacement. Therefore, if the ultrasonic flow meter is used, the strainer strainer exchange cycle becomes longer, and secondary contamination can be prevented.

  The gas return line 15 is sequentially attached with one of the fourth valve V4, the pipe joint 4, the flexible tube 24, and a plug and a socket from the branch point to the exhaust line 16 toward the transformer side. Further, the third valve V3, the pipe joint 4, the flexible tube 25, and one of the plug and the socket are sequentially attached from the branching point to the exhaust pipe line 16 toward the oil recovery device side.

  The exhaust pipe 16 is connected to a coupled meter 26, a fifth valve V5, and an activated carbon filter as a PCB removing means 27 in order from the branch point to the outside. By visually observing the compound meter 26, the internal pressure of the exhaust pipe 16 can be compared with the atmospheric pressure. The activated carbon filter 27 adsorbs PCB mixed with gas and discharges clean air to the outside.

  The control device for controlling the operation of the pump P and the opening / closing of the solenoid valve V0 is composed of the pump P, the flow rate detector (ultrasonic oil meter) 22, the weight detector (load cell) 9, the solenoid valve V0, and the flow switch 20 by wiring. Connected to the control panel 28 to perform computer control. The weight detection unit 9 detects the weight of the PCB insulating oil recovered in the oil recovery case 11 together with the oil recovery case 11 placed on the tray 10. The flow rate detection unit 22 detects the flow rate of the PCB insulating oil fed into the oil recovery case 11 between the driving and stopping of the pump P.

  The control panel 28 includes a weight setting unit 29, a flow rate setting unit 30, and a determination unit 31. The weight setting unit 29 may set the weight of the PCB insulating oil scheduled to be collected in the oil collecting case 11 including the weight of the oil collecting case 11 and the tray 10, or set only the weight of the PCB insulating oil. The oil recovery case 11 and the tray 10 may be set by different setting units. The flow rate setting unit 30 sets the flow rate of the PCB insulating oil that is to be recovered in the oil recovery case 11. Then, the determination unit 31 operates the pump P and opens / closes the electromagnetic valve V0 based on the detection results of both the flow rate detection unit 22 and the weight detection unit 9 and the set values of both the weight setting unit 29 and the flow rate setting unit 30. Therefore, when the detection result of one of the flow rate detection unit 22 and the weight detection unit 9 reaches a set value, the pump P is stopped and the electromagnetic valve V0 is closed. Also, when both detection results of the flow rate detection unit 22 and the weight detection unit 9 reach the set value at the same time, the pump P is stopped and the electromagnetic valve V0 is closed.

  The determination unit 31 grasps the decrease in the flow rate based on the detection signal from the flow switch 20, and stops the pump P and closes the electromagnetic valve V0 when the flow rate decrease reaches a predetermined level. The idling is prevented and the pump P is prevented from being damaged. In addition, the flow sight 19 is made so that the state (dirt, amount) of the oil in the pipe can be visually confirmed, and the worker visually confirmed that the oil was dirty or the oil amount was reduced to the extent that the pump was damaged. In this case, the forced stop switch of the control panel 28 can be operated.

When performing oil removal work, first, an operator connects the transformer 1, the oil removal device 3, and the oil recovery device 2 through the pipe joints 4, respectively, and is scheduled to recover to the weight setting unit 29 and the flow rate setting unit 30, respectively. Enter the set values (weight value, flow rate value). If not entered, the default condition stored in memory is used. The setting value of the flow rate setting unit 30 is less than the capacity of the oil recovery case to prevent leakage, and the setting value of the weight setting unit 29 is a value obtained by multiplying the general specific gravity of the PCB insulating oil and the scheduled recovery flow rate. And Then, as shown in the valve operation table of Table 1, the fifth valve is closed and the other valves are opened.

  Then, after visually confirming the flow site 19 and confirming that the amount of oil sufficient for driving reaches the pump P, when the pump P is driven by pressing the start switch of the control panel 28, the solenoid valve V0 is opened and the oil is recovered. PCB insulating oil flows into the case 11, while gas in the closed circuit flows into the transformer 1. Both the flow rate detection unit 22 and the weight detection unit 9 always send the detection result to the determination unit 31, and when the determination unit 31 reaches at least one of the detection results, the pump P automatically stops. The solenoid valve V0 is closed.

  Subsequently, in order to depressurize the oil recovery case 11, the operator closed the fourth valve V4, opened the fifth valve V5, and confirmed that the internal pressure of the oil recovery case 11 was reduced to the atmospheric pressure with the coupled meter 26. Check to prevent the oil recovery case 11 from being damaged.

  Next, the replacement work of the oil recovery case 11 is performed. First, the fourth valve V4 is opened, the fifth valve V5 is closed, and then the oil recovery case 11 in which PCB insulating oil is accumulated is removed, and the empty oil recovery case 11 is connected to the oil removal device 3. The third valve V3 is not closed when the oil recovery case 11 is replaced. This is because the PCB does not leak from the tip of the gas return line 15 by the pipe joint 4, and the replacement work itself is plugged. This is because it can be completed in a short time because the socket is only inserted and removed, and secondary contamination is unlikely to occur.

  Thereafter, when the start switch is pressed to perform the oil removal operation again, the solenoid valve V0 is automatically opened. Since the oil recovery case 11 has the same shape, the set values of the flow rate setting unit 30 and the weight setting unit 29 need not be changed. When the oil collection case 11 has accumulated the amount corresponding to the set value, it is replaced with an empty one and the operation of pressing the start switch is repeated. When the amount of oil remaining in the transformer decreases while the work is being performed and the amount of oil in the flow switch 20 reaches a predetermined level (when the PCB insulating oil in the transformer 1 is almost empty). The determination unit 31 stops the pump P and closes the electromagnetic valve V0. Further, in order to check the amount of oil accumulated in the oil recovery case 11 at this time, the detection result of the flow rate detection unit 22 is stored in the determination unit 31 and displayed in the control panel. And if it confirms that the oil quantity has not reached the set value, it can still be recovered in the oil recovery case, so that the operator can perform the depressurization operation of the transformer 1 while the oil recovery case 11 is connected to the oil extraction device 3. Move on.

  The pressure releasing operation of the transformer 1 is performed by closing the third and seventh valves V3 and V7, opening the fifth valve V5, and confirming that the internal pressure of the transformer 1 has become atmospheric pressure. It is desirable that the pressure-removing operation of the transformer 1 and the above-described pressure-removing operation of the oil recovery case 11 be performed in order to prevent secondary contamination even when the transformer 1 is not a gas-sealed type or a non-sealed type. .

  Subsequently, transformer replacement work is performed. First, the fifth and eighth valves V5 and V8 are closed, and then the transformer 1 that has been emptied is removed, and the oil removal device 3 and the oil recovery device 2 are connected to another transformer 1 while moving, The device 3 is connected to another transformer 1.

  Next, in order to perform oil removal work from the replaced transformer 1, the operator opens the parts other than the fifth valve V5. Then, the amount of oil accumulated in the oil recovery case 11 is subtracted from the original set value, the subtracted value is input to the flow rate setting unit 30, and the start switch of the pump P is pushed. Then, if the detection result from the flow rate detection unit 22 reaches the value reset by the flow rate setting unit 30 or the detection result from the weight detection unit 9 reaches the set value of the weight setting unit 29, the determination is made. The part 31 stops the pump P and closes the solenoid valve V0. Therefore, even if a value larger than the original value that should be set by the flow rate setting unit 30 is erroneously set, the determination unit 31 stops the pump P based on the set value of the weight setting unit 29, so that the oil recovery There is no possibility that the PCB insulating oil will overflow from the case 11.

  When the strainer 18 is replaced, the first and sixth valves V1 and V6 are closed while the pump P is stopped.

  As shown in FIGS. 3 and 4, in another example of the present invention, a flow site 32 is provided between the third valve V <b> 3 and the pipe joint 4 so that the oil can be visually recognized by the flow site when oil leaks into the gas return line. It is. Further, a connecting pipe 33 whose outlet side branches bifurcated is connected to the exhaust port 13, and a gas return pipe 15 is connected to one of the branch pipes of the connecting pipe 33 in the same manner as in the previous example, and the other of the branch pipes (an upright pipe A liquid level detector 34 (displacement sensor) 34 is attached to the upper part, and the liquid level detector 34 is connected to the control panel 28 by wiring.

  The control panel 28 is provided with a specific gravity / flow rate setting unit 35 to set an expected specific gravity and a planned recovery flow rate of the PCB insulating oil, and a weight calculation unit 36 is provided to multiply the expected specific gravity and the planned recovery flow rate to obtain the expected recovery weight. Is calculated. Further, the control panel 28 is provided with a weight correction unit 37, and the actual specific gravity of the PCB insulating oil is calculated by dividing the accumulated weight by using the detection results of both the flow rate detection unit 22 and the weight detection unit 9 and the flow rate. Then, the expected specific gravity is replaced with the actual specific gravity, and the estimated recovery weight is recalculated and corrected.

  Further, the control panel 28 is provided with a liquid level height setting unit 38 to set the expected recovery height and the warning height (the height that teaches that the expected recovery height has been approached). Then, when the detection result in the liquid level detection unit 34 reaches the warning level in the liquid level setting unit 34, the determination unit 31 first issues a warning with sound or the like, and then collects it. If the planned height is reached, the pump P is stopped. Further, in preparation for the case where the expected recovery height in the liquid level setting unit 38 is input by mistake, the determination unit 31 has a case where the detection result from the weight detection unit 9 reaches the correction weight by the weight correction unit 37. In addition, the pump P is stopped. Accordingly, the pump P is stopped at an early time when there is a future, or at the same time in the same period, when reaching the scheduled collection height and reaching the corrected weight.

  As an example of the case where the worker performs the oil removal work in the above example, the operator may press the start switch after inputting all the settings in the various setting units, but the oil recovery case 11 having the same shape is used. In this case, default conditions may be stored in a memory as various setting units so that the operator does not need to perform an input operation, and the stored setting values may be used. Then, when the start switch is pressed, the pump P is driven, the weight calculating unit 36 calculates the estimated collection weight, and when the pressing switch is grasped that the predetermined amount has passed through the flow rate detecting unit 22, the PCB insulating oil increased so far. Is obtained from the detection result of the weight detector 9, and the estimated collection weight is corrected. It should be noted that the accumulated flow rate is grasped from the detection result of the flow rate detection unit 22 after a short time (at least the time when it is impossible to reach the warning height) after being pushed, and the PCB insulating oil increased so far The weight may be grasped from the detection result of the weight detection unit 9 and the expected collection weight may be corrected. When the liquid level reaches the warning height, a warning sound is first generated. When the recovery weight reaches the recovery weight or the recovery height, the pump P is stopped.

DESCRIPTION OF SYMBOLS 1 Transformer 3 Oil removal apparatus 4 Pipe joint 6 Oil discharge port 7 Fluid supply port 9 Weight detection part 11 Oil recovery case (drum can)
12 Input port 13 Exhaust port 14 Oil removal line 15 Gas return line 16 Exhaust line P Pump 22 Flow rate detection unit 27 PCB removal means 29 Weight setting unit 30 Flow rate setting unit 31 Determination unit 34 Liquid surface height detection unit 35 Specific gravity / Flow rate setting unit 36 Weight calculation unit 37 Weight correction unit 38 Liquid level height setting unit V0 Solenoid valve

Claims (6)

  It consists of a transformer (1) containing PCB insulating oil, an oil recovery case (11), and an oil removal device (3). The oil discharge port (6) of the transformer (1) and the input port of the oil recovery case (11) ( 12) is connected to the oil removal line (14) of the oil removal device (3), and the fluid supply port (7) of the transformer and the exhaust port (13) of the oil recovery case are connected to the gas return line of the oil removal device (3). By connecting in (15), a closed circuit is formed, and the PCB insulating oil is recovered in the oil recovery case (11) by driving the pump (P) in the oil removal pipe (14), and in the closed circuit An oil removal system for a transformer, wherein the gas is collected in the transformer (1).   The exhaust pipe (16) is branched from the gas return pipe (15), and the exhaust pipe (16) has a fifth valve (V5) and a PCB removing means (27) in order toward the outlet, and the pump During operation, the fifth valve (V5) is closed to disable the exhaust pipe (16), and when the pump is stopped, the fifth valve (V5) is opened when the transformer (1) and the oil recovery case (11) are depressurized. The oil removal system for a transformer according to claim 1, wherein the exhaust pipe (16) is opened.   The oil drain line (14) has a solenoid valve (V0) on the oil recovery case side of the pump (P) and a sixth valve (V6) on the transformer side of the pump (P). V0) can be opened and closed in conjunction with the operation of the pump (P), and the gas return line (15) is provided with a fourth valve (V4) closer to the transformer than the branch point to the exhaust line (16). The oil removal system for a transformer according to claim 2, further comprising a third valve (V3) closer to the oil recovery case than the branch point.   At the location where the transformer (1) and oil recovery case (11) are connected to the oil removal device (3), a pipe joint (4) consisting of a plug and socket is used, and the plug and socket each have a fluid leakage prevention function. 4. The transformer oil removal system according to claim 3, wherein the oil removal system is a transformer. A control device for controlling the operation of the pump (P) is provided,
The control device includes a weight detection unit (9) that detects the weight of the PCB insulating oil collected in the oil recovery case together with the oil recovery case, and a flow rate detection unit that detects the flow rate of the PCB insulating oil sent from the pump to the oil recovery case ( 22), a weight setting unit (29) for setting a scheduled recovery weight to the oil recovery case, a flow rate setting unit (30) for setting a scheduled recovery flow rate to the oil recovery case, a flow rate detection unit, and a weight detection unit The detection unit (31) for stopping the pump based on both detection results and the set values of both the weight setting unit and the flow rate setting unit,
The determination unit stops the pump (P) when the detection result from the flow rate detection unit (22) reaches the planned recovery flow rate and when the detection result from the weight detection unit (9) reaches the planned recovery weight. The oil removal system for a transformer according to claim 3 or 4, characterized in that: A control device for controlling the operation of the pump (P) is provided,
The control device includes a weight detection unit (9) that detects the weight of the PCB insulating oil collected in the oil recovery case together with the oil recovery case, and a flow rate detection unit that detects the flow rate of the PCB insulating oil sent from the pump to the oil recovery case ( 22), a liquid level detector (34) for detecting the level of PCB insulating oil in the oil recovery case, and a specific gravity / flow rate setting unit (for setting the expected specific gravity of PCB insulating oil and the expected recovery flow rate) 35), a weight calculation unit (36) for calculating the estimated recovery weight from the expected specific gravity and the expected recovery flow rate, and a liquid level height setting unit (38) for setting the expected recovery level of the liquid level in the oil recovery case The weight correction unit (37) calculates the actual specific gravity of the PCB insulating oil from the detection results of both the flow rate detection unit and the weight detection unit and recalculates and corrects the estimated recovery weight based on the actual specific gravity and the expected recovery flow rate. And decision to stop the pump (P) Since the result (31),
The determination unit is configured such that the detection result from the weight detection unit (9) reaches the correction weight by the weight correction unit (37) and the detection result from the liquid level detection unit (34) is the liquid level height setting unit. The oil removal system for a transformer according to claim 3 or 4, characterized in that the pump (P) is stopped when the planned collection height according to (38) is reached.

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