JP2015078838A - Leakage detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leakage detection device capable of surely detecting leakage when leakage occurs due to breakage of piping such as oil feed piping.SOLUTION: The leakage detection device comprises double-shell oil feeding piping (3) whose one end is coupled to an underground tank (1) and whose the other end is coupled to an oil feeding device (2), which is buried underground, and in which a liquid feeding path is formed on an inner shell (31) and a space part is formed between the inner shell (31) and an outer shell (32), and further comprises leakage detection means (6) communicated to the space part (302).

Description

  The present invention relates to a detection device that detects leakage of piping (for example, a fuel pipe in a gas station).

For example, a fuel tank in which fuel oil such as gasoline buried in the land price of a gas station is stored and a fueling device installed on the ground are communicated by a fuel pipe buried in the ground.
In order to inspect such leaks in oil supply pipes, it is necessary to perform civil engineering work to dig up the oil supply pipes subject to leak inspection from the underground, and such civil engineering work requires a long period of work. In the meantime, the cost for the work is significant.
In the oil supply pipe leakage inspection, a special sensor may be inserted into the inspection target oil supply pipe, but the oil supply pipe cannot be used during the inspection period, and a special sensor is inserted. Pipes that can be inspected for leaks are also limited.

The present applicant has proposed a technique for determining leakage of an oil supply pipe using an existing oil supply mechanism (see Patent Document 1).
The technique proposed by the present applicant (Patent Document 1) is useful, but if the oil supply pipe to be subjected to leakage inspection is located below the groundwater, the groundwater will flow if the oil supply pipe is damaged. There is an inconvenience that leakage due to breakage of the oil supply pipe cannot be detected.

JP 2001-349800 A

  The present invention has been proposed in view of the above-described problems of the prior art, and when leakage occurs due to damage to piping (for example, a piping such as an oil supply pipe), the leakage can be reliably detected. The purpose is to provide a detection device.

The leak detection device (100) of the present invention includes:
One end is connected to the underground tank (1) and the other end is connected to the oil supply device (2), embedded in the basement, forming a liquid feed path in the inner shell (31), and the outer shell (31) and the outer shell A double shell oil supply pipe (3) having a space (302) formed between the shells (32);
Leakage detection means (6) communicating with the space (302) is provided.

Here, the leakage detection means (6) is a float chamber (610) having one end communicating with the space (302) and the other end communicating with the suction pump (5),
In the float chamber (610), it is preferable that a water float (62) movable up and down when water enters and an oil float (63) movable up and down when oil enters.
Alternatively, the leak detection means is preferably a pressure sensor (7).

In carrying out the present invention, for example,
The float chamber (610) is composed of a cylindrical body (61) capable of inflow of liquid,
The water float (62) is a float that produces buoyancy against water but settles against oil;
The oil float (63) creates buoyancy with respect to water and oil and is located above the water float (62);
The water float (62) and the oil float (63) are accommodated in the cylindrical body so as to be movable up and down,
It is preferable to provide a sensor (65) for outputting a signal when the water float (62) and the oil float (63) are separated by a certain length.

The leak detection device (100A) of the present invention
One end is connected to the underground tank (1) and the other end is connected to the oil supply pipe 3A connected to the liquid storage means (for example, the oil storage tank 2A) on the ground side (for example, the roof 51 of the building 50). 6A) is interposed.

  Here, the leakage detection means (6A) includes a plurality of opening / closing means (for example, two three-way electromagnetic valves V31 and V32 and an electromagnetic valve V in the vicinity of the oil storage tank 2A) interposed in the oil supply pipe (3A). A bypass pipe (3B) for bypassing a region between the two opening / closing means (V31, V32) provided in the oil supply pipe (3A), and a flow rate provided in the bypass pipe (3B) It is preferable to have meter-side means (for example, a flow meter Mq).

According to the present invention having the above-described configuration, leakage detection leading to the space (302) between the inner shell (31) and the outer shell (32) of the double-shell fuel pipe (3) buried underground. Since the means (6) is provided, when the outer shell (32) is broken and water enters the space portion (302), the intruded water leaks through the space portion (302). ), The leak detection means (6) can detect the intruded water and detect that the outer shell (32) is damaged.
On the other hand, when the inner shell (31) is broken, the oil flowing through the oil supply pipe (3) enters the space (302), and the intruded oil leaks through the space (302) to the leak detection means (6 ). The leakage detection means (6) can detect that oil has entered, and thus can detect that the inner shell (31) has been damaged.
That is, according to the present invention, either the outer shell (32) or the inner shell (31) of the double shell oil supply pipe (3) is damaged in the unmanned area without dug up the oil supply pipe (3). However, it can be detected reliably.

In the present invention, the leakage detection means (6) is a float chamber (610) having one end communicating with the space (302) and the other end communicating with the suction pump (5), If the vertically movable water float (62) and the vertically movable oil float (63) are disposed in the float chamber (610), the outer shell (32) is damaged and the oil supply pipe ( 3) When water enters the space (302), and the water that has entered reaches the leak detection means (6), the water float (62) rises, so that it is detected that the outer shell (32) is broken. I can do it.
On the other hand, when the inner shell (31) is damaged, the oil flowing through the oil supply pipe (3) reaches the leakage detection means (float chamber 610 of 6) through the space (302), and the oil float (63) Is raised, it is possible to detect that the inner shell (31) is broken.

  Further, in the present invention, when the leakage detection means (6) is a pressure sensor (7), for example, when the oil supply pump is stopped and the supply of oil via the oil supply pipe (3) is stopped, the leakage is detected. The presence or absence of leakage in the oil supply pipe (3) can be determined based on the pressure change characteristic measured by the pressure sensor (7) which is a detection means.

Here, there are many cases where the generator (70) is installed on the roof (51) of a building (for example, the building 50) for the purpose of supplying power during a disaster. In such a case, liquid storage means (oil storage tank 2A) for storing fuel for driving the generator (70) is also installed on the roof of the building (50).
When supplying oil to the liquid storage means (2A), the oil stored in the underground tank (1) provided directly under the building or in the vicinity of the underground is passed through the underground pipe and the ground side pipe (3A). And supply it to the roof of the building (50). In preparation for a disaster or other emergency, it is necessary to inspect for leakage in the oil supply pipe (3A) communicating with the liquid storage means (2A) on the roof of the building (50).
However, since the pipe (3A) has a long overall length and is often arranged in a region where the ground height is high, if the leak inspection is performed manually by a worker, a great cost is required, and A great deal of effort will be expended to ensure safety during the inspection.

According to the leak detection apparatus (100A) of the present invention, one end is connected to the underground tank (1) and the other end is a liquid storage means (for example, oil storage tank 2A) on the ground side (for example, the roof 51 of the building 50). Since the leakage detection means (6A) is interposed in the oil supply pipe (3A) connected to the pipe, it is not necessary to perform it manually by the worker.
Therefore, it is possible to save the cost of the leakage inspection, and it is not necessary for the worker to work in an area where the ground height is high during the leakage inspection.

Here, the leakage detection means (6A) is provided with a plurality of opening / closing means (for example, two three-way solenoid valves V31, V32 and an electromagnetic valve in the vicinity of the oil storage tank 1A) interposed in the oil supply pipe (3A). A bypass pipe (3B) that bypasses a region between the two opening / closing means (V31, V32) interposed in the oil supply pipe (3A), and a flow meter interposed in the bypass pipe (3B) If the side means (for example, the flow meter Mq) is provided, the oil supply pipe (3A) is closed with the opening / closing means (the electromagnetic valve V near the oil storage tank) near the liquid storage means (oil storage tank 2A) closed. The two installed opening / closing means (V31, V32) are operated to switch the two opening / closing means (V31, V32) to the bypass pipe (3B) side.
If there is no breakage in the oil supply pipe (3A) and there is no leakage, the opening / closing means (electromagnetic valve V near the oil storage tank) in the vicinity of the liquid storage means (oil storage tank 2A) is closed. Even if the opening / closing means (V31, V32) are switched to the bypass pipe (3B) side, the oil does not flow, and the flow rate of the oil measured by the flowmeter side means (for example, the flowmeter Mq) becomes zero.
On the other hand, if the oil supply pipe (3A) has a damaged portion and oil has leaked, even if the open / close means (the electromagnetic valve V near the oil storage tank) near the liquid storage means (oil storage tank 2A) is closed, Since oil leaks from the damaged portion, the flow rate of oil measured by the flow meter side means (for example, the flow meter Mq) does not become zero.

Therefore, if the flow rate of oil measured by the flow meter side means (Mq) is zero, the oil supply pipe (more specifically, the liquid storage means or oil storage tank 2A side area than the bypass pipe 3B) is leaking. Judged not.
On the other hand, if the oil flow rate measured by the flow meter side means (Mq) is not zero, the oil supply pipe (more specifically, the liquid storage means or oil storage tank 2A side area than the bypass pipe 3B) leaks. It is judged that That is, according to the present invention, leakage of fuel oil can be detected by remote operation without relying on human hands.

1 is a block diagram showing a first embodiment of the present invention. It is a block diagram of the control device in the first embodiment. It is a flowchart which shows the control in 1st Embodiment. It is a figure which shows an example of the pressure characteristic during performing the control shown in FIG. FIG. 5 is a diagram illustrating an example of a pressure characteristic during execution of the control illustrated in FIG. 3, and illustrates a pressure characteristic different from that in FIG. 4. It is a flowchart which shows the control in 2nd Embodiment of this invention. It is a block diagram which shows 3rd Embodiment of this invention. It is a flowchart which shows the control in 3rd Embodiment. It is a block diagram which shows the modification of 3rd Embodiment of this invention. It is a flowchart which shows the control in the modification of 3rd Embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, a first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, a leak detection device denoted as a whole by reference numeral 100 includes an oil supply pipe 3, a leak fluid suction pipe 4, a suction pump 5, a leak detection means 6, a pressure sensor 7, and a double shell. The check valve 8, the control unit 10, and the liquid amount management device 20 are provided.

The oil supply pipe 3 composed of a double shell includes an inner shell (hereinafter referred to as “inner tube”) 31 having a circular cross section and an outer shell (hereinafter referred to as “outer tube”) concentric with the inner tube 31. 32, and the underground tank 1 and the ground oil supply device 2 communicate with each other. Fuel oil flows through the inside 301 of the inner tube 31.
A space (hereinafter referred to as “annular space”) 302 is formed in a region between the inner tube 31 and the outer tube 32 in the oil supply pipe 3.
One end of the leakage fluid suction pipe 4 communicates with the annular space 302 via the fluid suction adapter 41, and the other end of the leakage fluid suction pipe 4 communicates with the suction pump 5.

In FIG. 1, the leak detection means 6 has a cylindrical leaked fluid reservoir 61, a disc-shaped water float 62, a disc-shaped oil float 63, a guide rod 64, and a water / oil identification sensor 65. ing. The internal space 610 of the cylindrical leaked fluid reservoir 61 is referred to as a “float chamber”. The leaking fluid suction pipe 4 is divided into two by a float chamber 610.
As will be described later, in the first embodiment of FIG. 1, leakage detection is mainly performed by the pressure sensor 7.

Although not clearly shown in FIG. 1, a through hole through which the guide rod 64 is inserted is formed at the center of both the disk-shaped water float 62 and the disk-shaped oil float 63. That is, the water float 62 and the oil float 63 are configured so as to freely move up and down along the guide rod 64 in the vertical direction.
The water float 62 is made of a material that produces buoyancy with respect to water but settles with respect to oil. On the other hand, the oil float 63 is located above the water float 62 and is made of a material that generates buoyancy with respect to both water and oil.
The water / oil identification sensor 65 is fixed to the top of the guide rod 64 and is configured to output a signal when the water float 62 and the oil float 63 are separated by a certain distance.
Here, the leak detection means 6 can be configured by a known means.

A pressure sensor 7 is interposed in a region between the float chamber 610 and the suction pump 5 of the leakage fluid suction pipe 4.
A check valve 8 is interposed in a region between the pressure sensor 7 and the suction pump 5 of the leakage fluid suction pipe 4. The liquid containing air sucked by the suction pump 5 flows from the float chamber 610 to the suction pump 5 side, but the reverse flow is blocked.
The suction pump 5 has a gas-liquid separation mechanism (not shown), opens the sucked gas to the atmosphere, and the sucked liquid is separated from the gas by the gas-liquid separation mechanism and discharged outside the pump 5. The Note that a gas-liquid separation mechanism (not shown) can be interposed in a region between the check valve 8 and the suction pump 5.

The control unit 10 is connected to the water / oil discrimination sensor 65 in the leakage detection means 6 via the input signal line Li1, and is connected to the pressure sensor 7 via the input signal line Li1.
The control unit 10 is connected to the suction pump 5 via a control signal line (output signal line) Lo, and is connected to the liquid amount management device 20 via a signal line Ls.

Next, the configuration and function of the control unit 10 will be described with reference to FIG.
In FIG. 2, the control unit 10 includes a data storage block 11, a first comparison block 12, a first determination block 13, a pump control signal generation block 14, a pressure waveform determination block 15, and a second determination. A block 16, an abnormality cause determination block 17, an alarm block 18, and a third determination block 19 are provided.

The first comparison block 12 is connected to the pressure sensor 7 via a line L72, is connected to the data storage block 11 via a line L12, and is connected to the second determination block 13 via a line L23. The input signal from the pressure sensor 7 (pressure value of the leaked fluid suction pipe 4) and the data stored in the data storage block 11 are compared.
The data stored in the data storage block 11 transmitted to the first comparison block 12 is a threshold value (threshold value) indicating whether or not the suction pump 5 is stopped, and is a pressure value.

The first determination block 13 is connected to the pump control signal generation block 14 via a line L34, and the comparison result in the first comparison block 12 is input. Then, based on the comparison result in the first comparison block 12, it is determined whether or not the pressure value of the leakage fluid suction pipe 4 is equal to or greater than a predetermined value. The first determination block 13 is configured to output the determination result to the pump control signal generation block 14.
The pump control signal generation block 14 is connected to the pump 5 through a line L45, and has a function of outputting a pump stop or pump start control signal to the suction pump 5 based on the determination result of the first determination block 13. Yes.

The pressure waveform determination block 15 is connected to the pressure sensor 7 via a line L75, and is connected to the second determination block 16 via a line L56.
The pressure waveform determination block 15 has a function of determining (or creating) a pressure waveform (for example, a waveform as shown in FIGS. 4 and 5) based on the measurement result of the pressure sensor 7.

The second determination block 16 is connected to the data storage block 11 through a line L16, and is connected to the abnormality cause determination block 17 through a line L67.
The second determination block 16 compares and collates the waveform data stored in the data storage block 11 (for example, the waveform data in FIGS. 4 and 5) with the waveform data created in the pressure waveform determination block 15, The collation result is output to the abnormality cause determination block 17.

The abnormality cause determination block 17 is connected to the data storage block 11 via a line L17, and is connected to the alarm block 18 via a line L78.
The abnormality cause determination block 17 determines the presence / absence of an abnormality based on the collation result in the second determination block 16 and the information from the data storage block 11, and outputs the determination result (absence / absence of abnormality) to the alarm block 18. It is configured as follows.
The information sent from the data storage block 11 to the second decision block 16 includes information on a waveform in a normal state (for example, indicated by a symbol α in FIG. 4), a waveform when an abnormality occurs (for example, a symbol in FIG. 5). information).

The third determination block 19 is connected to the water / oil identification sensor 65 via a line L69, and is connected to the alarm block 18 via a line L98.
The third determination block 19 determines whether the cause of the abnormality is due to water intrusion into the annular space 302 in the oil supply pipe 3 or the annular space in the oil supply pipe 3 based on the information sent from the water / oil identification sensor 65. It is configured to identify whether the fuel oil leaks to 302.
However, the line L69 can be omitted, and the third determination block 19 can be configured to identify the cause of the abnormality without depending on the information from the water / oil identification sensor 65. Since the pressure waveform indicating the abnormality differs depending on the cause of the abnormality, the waveform data stored in the data storage block 11 (for example, the waveform data α and β in FIGS. 4 and 5) and the waveform created by the pressure waveform determination block 15 are used. This is because the cause of the abnormality can be identified by comparing and collating with the data.

The alarm block 18 is connected to the flow rate management device 20 via a line L80.
When the alarm block 18 should issue an alarm based on the presence / absence of an abnormality from the abnormality cause determination block 17 and the cause of the abnormality specified in the third determination block 19, the content of the abnormality is indicated to the flow rate management device 20. To send.

Next, based on FIG. 3, the control of the fuel oil leakage detection in the first embodiment will be described.
In step S1 of FIG. 3, the suction pump 5 is activated and the process proceeds to step S2. When the suction pump 5 is driven, the measured value (detected pressure) of the pressure sensor 7 increases.
In step S2, the control unit 10 determines whether or not the pressure in the leaked fluid suction pipe 4 detected by the pressure sensor 7 is equal to or higher than a set value A (first threshold: see FIGS. 4 and 5). To do.
If the pressure in the leaked fluid suction pipe 4 is less than the set value A (step S2 is NO), step S2 is repeated. On the other hand, if the pressure in the leakage fluid suction pipe 4 reaches the set value A (YES in step S2), the process proceeds to step S3.

In step S3, the suction pump 5 is stopped and the process proceeds to step S4. By stopping the suction pump 5, the pressure detected by the pressure sensor 7 is reduced.
In step S4, it is determined whether or not the pressure in the leakage fluid suction pipe 4 is less than the set value A and greater than or equal to the set value B.
Here, the set value A and the set value B are such that if the pressure of the detected fluid is less than the set value A to the set value B or more, leakage in the oil supply pipe 3 can be reliably detected, and costs related to measurement can be minimized. It is desirable to select a correct value.
If the pressure in the leakage fluid suction pipe 4 is less than the set value A and greater than the set value B (YES in step S4), the process proceeds to step S5. On the other hand, if the detected pressure decreases and becomes less than the set value B (NO in step S4), the process proceeds to step S7.

In step S5 (the pressure in the leakage fluid suction pipe 4 is less than the set value A and greater than or equal to the set value B), leak detection is performed. That is, whether the pressure waveform detected by the pressure sensor 7 by the pressure waveform determination block 15 and the second determination block 16 of the control unit 10 is the type indicated by the symbol α in FIG. 4 or the symbol β in FIG. Is determined.
For example, in the normal state where there is no fluid leakage, the detected pressure waveform is a type with a long period indicated by symbol α in FIG. 4, and when there is a fluid leakage abnormality, a type with a short cycle indicated by symbol β in FIG. 5. If the detected pressure waveform is α type (“α” in step S5), it is determined that there is no leakage and the process returns to step S4.

On the other hand, if the detected pressure waveform is β type (“β” in step S5), it is determined that there is a leak and the process proceeds to step S6, where the alarm block 18 leaks to the flow rate management device 20. After outputting a signal to that effect, the process returns to step S4.
Here, the case where the outer tube 32 is broken and water enters the annular space 302 and the case where the inner tube 31 is broken and the oil leaks are the characteristics of the type indicated by β in FIG. However, the inventors' research has revealed that the circumference, amplitude, and waveform are different. Accordingly, it is possible to determine whether the outer tube 32 is damaged or the inner tube 31 is damaged from above the pressure waveform determination block 15 of the control unit 10.

In step S7 (less than the set value B), the suction pump 5 is started again, and the process proceeds to step S8.
In step S8, the control unit 10 determines whether or not to end the leakage inspection. If it is during business hours (the business hours are checked by a timer), the process returns to step S2 and repeats step S2 and subsequent steps. On the other hand, if the business hours are over and the leakage inspection is finished, the entire control is finished.

According to the first embodiment having the above-described configuration, when the supply of oil via the oil supply pipe 3 is stopped, the pressure is measured by the pressure sensor 7 as a leak detection means, and the change (pressure change) characteristic of the measured value is measured. The presence or absence of leakage in the oil supply pipe 3 is determined. Then, without digging up the oil supply pipe 3, it is possible to reliably detect whether the outer tube 32 or the inner tube 31 of the double shell oil supply pipe 3 is damaged in an unmanned region.
However, it is possible to detect leakage by the leakage detection means indicated by reference numeral 6. In the second embodiment to be described next, leakage is detected by the leakage detection means 6.

Next, a second embodiment of the present invention will be described.
The configuration of the leakage device 100 of the second embodiment is the same as that of the first embodiment, but the control of the second embodiment is different from the control of the first embodiment.
In the second embodiment, the water / oil identification sensor 65 in the leakage detection means 6 monitors the water float 62 and the oil float 63, and the movement of the water float 62 and the oil float 63 (the water float 62 and the oil float 63 ) Based on the relative position, it is determined on which side of the inner shell 31 and the outer shell 32 of the oil supply pipe 3 damage including cracks has occurred.
Hereinafter, the control in the second embodiment will be described mainly based on FIG. 6 and also referring to FIG.

In step S11 of FIG. 6, the water / oil identification sensor 65 of the leakage detection means 6 determines whether or not the water float 62 has risen. If the water float 62 rises (YES in step S11), the process proceeds to step S12, and the third determination block of the control unit 10 notifies the alarm block 18 that the outer tube 32 has been damaged, and then performs control. finish.
The rise of the water float 62 means that water is accumulated in the annular space 302, and the accumulation of water in the annular space 302 means that the outer tube 32 is broken and the groundwater is caused to flow into the annular space 302. It means that you have entered.

On the other hand, if the water float 62 has not risen (NO in step S11), the process proceeds to step S13. In step S <b> 13, it is determined whether or not the oil float 63 is rising away from the water float 62.
If the oil float 63 is rising away from the water float 62 (YES in step S13), a signal to the effect that the inner tube 31 is damaged is notified to the alarm block 18 in step S14, and then the control is terminated. . If the oil float 63 rises away from the water float 62, it means that only the oil has accumulated in the annular space 302, the inner tube 31 has been damaged, and the oil has entered the annular space 302. Yes.
On the other hand, if the oil float 63 does not rise from the water float 62 (NO in step S13), the process returns to step S11 and repeats step S11 and subsequent steps.

According to the second embodiment described above, the leak detection means 6 that leads to the annular space 302 between the inner tube 31 and the outer tube 32 of the double-shell fuel supply pipe 3 buried underground is provided. When the tube 32 is broken and water enters the annular space 302, the intruded water reaches the leakage detection means 6 via the annular space 302, and the leakage detection means 6 detects the intruded water. It is possible to detect that the outer tube 32 is broken.
On the other hand, when the inner tube 31 is broken, the oil flowing through the oil supply pipe 3 enters the space portion 302, and the intruded oil reaches the leak detection means 6 through the space portion 302. Then, it is possible to detect that the inner tube 31 is broken by detecting the oil that has entered the leak detection means 6.
That is, also in the second embodiment, without digging up the oil supply pipe 3, it is ensured that any of the outer tube 32 and the inner tube 31 of the double shell oil supply pipe 3 is damaged in an unmanned region. Can be detected.

Next, a third embodiment of the present invention will be described.
In the third embodiment shown in FIG. 7 and FIG. 8, a generator is installed on the roof of the building, and liquid storage means for storing fuel for driving the generator is also installed on the building roof. When oil is supplied from the underground tank directly under the building or in the vicinity of the building to the building roof via underground piping and ground-side piping, oil pipes are provided as a preparation for disasters and other emergencies. FIG.
The third embodiment will be described below with reference to FIGS. In the third embodiment, for example, an operator performs an operation.

In FIG. 7, an emergency generator 70 is installed on the roof 51 of a building 50, and an oil storage tank 2A is arranged in the vicinity thereof. On the other hand, an underground tank 1 is buried in the basement near the building 50.
The underground tank 1 and the oil storage tank 2A on the building rooftop 51 are connected by an oil supply pipe 3A, and the oil storage tank 2A on the building rooftop 51 and the generator 70 are connected by a connection pipe 3C.

Inside the underground tank 1 in the oil supply pipe 3A, a pump P for feeding fuel hydraulic pressure is disposed.
In FIG. 7, a leak detection device (shown by a dotted line) indicated as a whole by reference numeral 100 </ b> A includes a leak detection means 6 </ b> A interposed in the oil supply pipe 3 </ b> A and an operation panel 10 </ b> A having a display unit 10 Ma.
In the example of FIG. 7, the leak detection means 6 </ b> A is configured by a mechanism including a valve provided at a location near the underground tank 3 </ b> A and a location near the oil storage tank 2 </ b> A.

The location leakage detection means 6A in the vicinity of the underground tank 3A includes two three-way valves V31 and V32, a bypass flow path 3B, and a flow meter Mq.
The two three-way valves V31 and V32 are arranged in the vicinity of the underground tank 1 in the oil supply pipe 3A. The bypass flow path 3B is a flow path that connects a unique port of each of the three-way valves V31 and V32 to bypass a region between the three-way valves V31 and V32 of the oil supply pipe 3A. The flow meter Mq is interposed in the middle of the bypass flow path 3B.
On the other hand, the location leakage detection means 6A in the vicinity of the oil storage tank 2A includes a solenoid valve V interposed in a region in the oil supply pipe 3A in the vicinity of the oil storage tank 2A.

  The operation panel 10A is connected to the flow meter Mq through the input signal line Si1, is connected through the three-way valve V31 and the control signal line So1, and is connected through the three-way valve V32 and the control signal line Lo2. The operation panel 10A is further connected to the level sensor Sq inside the oil storage tank 2A by the input signal line Si2, and is connected to the solenoid valve V by the control signal line So3.

Hereinafter, based on FIG. 8, control of 3rd Embodiment is demonstrated. As described above, the control in FIG. 8 is executed by, for example, an operator.
In step S21 of FIG. 8, when normal refueling operation is performed (“normal” in step S21), the process proceeds to step S22, the operation panel 10A is operated to open the electromagnetic valve V, and the three-way valves V31 and V32 are operated. Thus, the fuel oil does not flow through the bypass flow path 3B, but is caused to flow from the underground tank 1 toward the oil storage tank 2A (flow of arrow FA in FIG. 7).

At this time, the remaining amount of fuel oil in the underground tank 1 is displayed on the display portion 10Ma of the display board 10A based on the measurement result of the level sensor Sq inside the oil storage tank 2A. In step S23 following step S22, the worker checks the remaining amount displayed on the display unit 10Ma, and determines whether or not it is necessary to supply fuel oil to the oil storage tank 2A on the roof 51.
If it is necessary to supply fuel oil (YES in step S23), the process proceeds to step S24, the pump P is driven, the process returns to step S23, and step S23 and subsequent steps are repeated again.
On the other hand, if sufficient fuel oil is stored in the oil storage tank 2A and it is not necessary to supply the fuel oil (NO in step S23), the process proceeds to step S25, and the pump P is stopped.

In step S21, if it is necessary to perform a leak test ("leak test" in step S21), the process proceeds to step S26. In step S26, the operator operates the operation panel 10A to close the electromagnetic valve V, and then operates the three-way valves V31 and V32 so that the fuel oil flows through the bypass flow path 3B (the flow of the arrow FB in FIG. 7). Like that.
Then, the worker drives the pump P in the underground tank 1 (step S27), and checks the flow meter Mq (step S28).
In step S28, when the flow rate is measured by the flow meter Mq (step S28 is YES), the process proceeds to step S29. On the other hand, if the flow rate is zero with the flow meter Mq (there is no measurement amount: step S28 is NO), the process proceeds to step S32.

Since the solenoid valve V is closed in step S26, the fuel oil should not flow in the pipe 3A, but if the fuel oil leaks from the pipe 3A, the flow meter Mq measures the leak amount as a flow rate. To do. Therefore, measuring the flow rate with the flow meter Mq (step S29) means that fuel oil is leaking from the pipe 3A. Therefore, in step S29 (when the flow rate is measured by the flow meter Mq), the worker determines that “the piping is damaged” and stops the pump P (step S30). In step S31, a warning of occurrence of damage (for example, sounding a warning buzzer) and display are performed and displayed on the operation panel 10A, and the leakage inspection is terminated.
It is possible to obtain the amount of leakage per unit time and detect the degree of breakage.

Since the solenoid valve V is closed in step S26, the fuel oil does not flow in the pipe 3A. Therefore, if the fuel oil does not leak from the pipe 3A, the flow rate measured by the flow meter Mq becomes zero. Therefore, in step S32 (when there is no measured amount in the flow meter), the worker determines that “the piping is not damaged”.
In step S33, it is determined whether or not to end the pipe damage inspection. If the pipe damage inspection is to be ended (YES in step S33), the pump P is stopped in step S34. On the other hand, if the leakage inspection is to be continued (NO in step S33), the process returns to step S26, and step S26 and subsequent steps are repeated.

According to the third embodiment shown in the figure, the leakage detection means 6A is interposed in the oil supply pipe 3A having one end connected to the underground tank 1 and the other end connected to the oil storage tank 2A on the roof 51 of the building 50. In addition, it is not necessary to perform a leak inspection manually by the worker over the entire area of the oil supply pipe 3A.
Therefore, it is possible to save the cost of the leakage inspection, and it is not necessary for the worker to work in an area where the ground height is high during the leakage inspection.

Here, in the third embodiment, the leakage inspection itself detects the leakage of the fuel oil by remote operation without relying on human hands. Therefore, it is also possible to perform a leak inspection fully automatically without using an operator. In the modification of the third embodiment shown in FIGS. 9 and 10, the leakage inspection is performed fully automatically.
That is, in the third embodiment shown in FIGS. 7 and 8, the worker is executing, but in the modified examples shown in FIGS. 9 and 10, all operations are performed by automatic control.

The operation panel 10A equipped with the display unit 10Ma in the third embodiment in FIG. 7 is replaced with a control unit 10B connected to the display unit 15 in the modification shown in FIG.
The control unit 10B has two control modes: a normal oil supply mode for the oil storage tank 2A and a self-leakage detection mode for the oil supply pipe 3A. These two control modes are automatically switched in one control flow.
In the normal refueling mode, the electromagnetic valve V is opened, and the three-way valves V31 and V32 are directed directly from the underground tank 1 to the oil storage tank 2A without flowing through the bypass passage 3B (flow of arrow FA in FIG. 9). Can be switched.
On the other hand, in the leakage detection mode (self-diagnosis mode) of the fuel supply pipe 3A, the solenoid valve V is closed, and the three-way valves V31 and V32 are switched so that the fuel oil flows through the bypass flow path 3B (the flow of the arrow FB in FIG. 9). It is done.

The leak detection is basically performed in the same manner as in the third embodiment. That is, the electromagnetic valve V is closed, the three-way valves V31 and V32 are switched to the bypass flow path 3B side, and the transport pump P is driven.
If the oil supply pipe 3A is not damaged and is not leaking, the electromagnetic valve V is closed, so the flow meter Mq interposed in the bypass flow path 3B indicates zero flow rate. On the other hand, if there is a break in the refueling interval 3A and the fuel oil is leaking, the flow meter Mq measures the leakage amount as a flow rate.

Next, control in a modification of the third embodiment will be described with reference to FIG.
In FIG. 10, the system is activated in step S41. Only when this system is activated, the worker turns on the activation switch of the control unit. In subsequent step S42, the electromagnetic valve V is automatically opened, and the three-way valves V31 and V32 are operated so that the flow of fuel oil in the oil supply pipe 3A becomes the flow of FA in FIG.

In the next step S43, the control unit 10B determines whether it is necessary to supply fuel oil to the roof tank (oil storage tank) 2A based on information from the level sensor Sq inside the oil storage tank 2A. If it is necessary to supply fuel oil to the oil storage tank 2A (YES in step S43), the pump P is driven in step S44, and steps S43 and S44 are repeated.
On the other hand, if it is not necessary to supply the fuel oil to the oil storage tank 2A (NO in step S43), the pump P is stopped in step S45, and then the process proceeds to step S46.

In step S46, the control unit 10B determines whether or not the leakage check of the oil supply pipe 3A should be performed.
Whether or not the leakage inspection of the fuel supply pipe 3A should be performed and the interval of the leakage inspection are set on a case-by-case basis in accordance with the facility usage status, requests in the Fire Service Act, and other conditions.
When the leakage inspection of the oil supply pipe 3A is to be performed (YES in step S46), the process proceeds to step S47. On the other hand, if it is not the case where the leakage inspection of the oil supply pipe 3A is to be performed (NO in step S46), step S42 and subsequent steps are repeated.

In step S47 (when leakage inspection of the oil supply pipe 3A is to be performed), the control unit 10B closes the electromagnetic valve V and switches the three-way valves V31 and V32 to the bypass flow path 3B side. In step S48, the pump P in the underground tank is driven.
As described above, since the electromagnetic valve V is closed, if there is no damage in the region between the three-way valve V32 and the electromagnetic valve V in the oil supply pipe 3A and there is no leakage point, measurement is performed with the flow meter Mq. The flow rate is zero.
On the other hand, if the fuel supply pipe 3A is damaged and the fuel oil is leaking, the flow meter Mq measures the leakage amount of the fuel oil as a flow rate and outputs it to the control unit 10B.

In step S49 following step S48, the control unit 10B determines whether or not the flow rate measured by the flow meter Mq is not zero based on the output information. If the flow rate measured by the flow meter Mq is zero (NO in step S49), it is determined in step S50 that "the piping (oil supply pipe) 3A is not damaged", and the content is displayed on the display unit 15. And it returns to step S43 and repeats after step S43 again.
On the other hand, if the flow rate measured by the flow meter Mq is not zero (YES in step S49), the process proceeds to step S51.

  In step S51, the control unit 10B determines that “the piping (oil supply pipe) 3A is damaged”. In step S52, the occurrence of damage and the contents are displayed on the display unit 15, and a warning is issued by a warning, which is recorded in a storage device (not shown in FIG. 9). Then, the process proceeds to step S53.

Here, when determining in step S49, if the flow rate measured by the flow meter Mq is very small, the control unit 10B may be configured to determine that the amount of leakage of fuel oil is negligibly small. Is possible. In other words, if the leakage amount of the fuel oil is within a predetermined value and the leakage amount does not change even after a predetermined time has elapsed, it can be determined that “the piping (oil supply pipe) 3A is not damaged”. .
On the other hand, if the leakage amount is equal to or greater than the threshold value or the leakage amount increases by a predetermined percentage or more within a predetermined time, it is possible to judge that the state is dangerous and to warn to that effect.

In step S53, the control unit 10B determines whether or not to end the inspection. If the inspection is to be ended (YES in step S53), the control is ended as it is.
On the other hand, if the inspection is continued (NO in step S53), the process proceeds to step S54, the pump is stopped, and the process returns to step S42.

According to the modification of the third embodiment described above, since almost all of the control is automated, the operating cost of the oil supply system including the leak inspection can be kept low except when a leak occurs.
In addition, if the amount of leakage per unit time is obtained in the control unit 10B, the degree of breakage can also be detected. Furthermore, it is possible to respond immediately to an emergency situation by checking the change in the amount of leakage in time.
Other configurations and operational effects in the modified examples of FIGS. 9 and 10 are the same as those of the third embodiment of FIGS.

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Underground tank 2 ... Oil supply apparatus 3 ... Double shell oil supply pipe 4 ... Leakage fluid suction pipe 5 ... Suction pump 5
6 ... Leakage detection means 7 ... Pressure sensor 8 ... Check valve 10 ... Control unit 20 ... Liquid quantity management device

Claims (5)

A double shell with one end connected to an underground tank and the other end connected to a fueling device, buried underground, forming a liquid feed path in the inner shell, and forming a space between the inner shell and the outer shell With a refueling pipe
A leak detection apparatus comprising a leak detection means that communicates with the space. The leak detection means is a float chamber having one end communicating with the space and the other end communicating with a suction pump.
2. The leak detection device according to claim 1, wherein a water float that can move up and down when water enters and an oil float that can move up and down when oil enters are arranged in the float chamber.   The leak detection device according to claim 1, wherein the leak detection means is a pressure sensor.   A leak detection apparatus characterized in that a leak detection means is interposed in an oil supply pipe having one end connected to an underground tank and the other end connected to a liquid storage means on the ground side.   The leakage detection means includes a plurality of opening / closing means interposed in the oil supply pipe, and bypass piping for bypassing a region between the two opening / closing means interposed in the oil supply pipe; 5. The leak detection device according to claim 4, further comprising intervening flow meter side means.

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