JP2009008620A - Leakage inspection device of underground tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leakage inspection device capable of attempting to enhancement in throughput of inspection task by inhibiting long-temporalized of inspection task hours. <P>SOLUTION: At the time when the measured value of pressure of a gaseous phase section within an underground tank with a pressure gauge reaches a specified pressure corresponding to an inspection pressure value, prior to initiation for the leakage judgment processing, an inspection initiation transition confirmation processing is implemented to judge whether or not shift to the leakage judgment processing is permitted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an underground tank leakage inspection apparatus for inspecting whether or not a liquid stored in an underground tank leaks, and more particularly to an underground tank leakage inspection suitable for detecting leakage from a gas phase portion in the underground tank. Relates to the device.

  Conventionally, in reservoirs where dangerous materials such as gasoline and other fuel oil are stored in underground tanks, in order to prevent soil contamination and fire accidents due to leakage of fuel oil etc. from underground tanks, It is mandatory by law to conduct airtight leak inspections regularly.

  Regarding the airtight leak inspection of underground tanks buried underground and storing dangerous materials such as fuel oil, when performing airtight leak inspection with liquid stored, the gas phase part which is the space part in the underground tank In addition, it is obliged to conduct a leakage inspection on both the liquid phase part, which is a part where the liquid such as fuel oil is stored.

For example, an airtight leak inspection of the gas phase portion in the underground tank is performed by holding the underground tank hermetically with the pressure state of the gas phase portion set to a predetermined slightly pressurized state P ₀ (2 kPa) with respect to the atmospheric pressure. In the case of a slight pressurization test for determining the presence or absence of leakage from the pressure change of the phase part, the following procedure is performed.

FIG. 10 is an explanatory diagram of the fine pressure test.
First, adjustment of equipment such as a pressure measuring device and a pressurizing device included in the leakage inspection apparatus is performed. And while connecting a pressure measuring device to the gaseous-phase part in an underground tank, a slight pressurization apparatus is connected to the gaseous-phase part in an underground tank. Then, other connecting portions communicating with the underground tank, for example, opening portions such as a liquid level gauge and a detection port are closed, and the underground tank is sealed from the outside.

  Then, the pressure state of the gas phase in the sealed underground tank is monitored for a predetermined time (more than 5 minutes), and the atmosphere in the underground tank and the piping connected to the underground tank is stable (equilibrium). Make sure that

After this confirmation, the operation of supplying the pressurizing device for supplying high-pressure sealed gas (nitrogen gas) and the opening / closing operation of the on-off valve connected to the pressurizing device are performed, and the gas phase section in the underground tank Sealing of the gas is started, and pressurization of the gas phase in the underground tank is started (FIG. 10, T ₀ ).

After the start of pressurization with the sealed gas to the gas phase part in the underground tank, the pressure state of the gas phase part in the underground tank is monitored by the measurement output of the pressure measuring device. Adjust the valve opening amount of the on-off valve as necessary, and gradually fill the gas phase in the underground tank to the gas phase in the underground tank by taking about 1 minute or more per 1 m ^{3 of the} gas phase (space volume). Enclose in. As a result, the pressure in the gas phase section in the underground tank is pressurized to a predetermined inspection pressure value P ₀ (FIG. 10, T ₁ ).

At a pressure in the vapor phase inspection pressure value P ₀ near the underground tank, so that the pressure of the gas phase portion does not become over-pressurized relative to the examination pressure value P _0, the adjustment operation of the valve opening amount of the opening and closing valve Then, the pressure is further gradually increased (FIG. 10, T ₂ ).

Thereafter, if the measured output of the pressure measuring unit has reached the test pressure value P _0, the on-off valve and closing operation stops encapsulation of filler gas, while maintaining the airtightness of the gas phase portion in the underground tanks, pressurized The pressure device is disconnected from the underground tank (FIG. 10, T ₃ ).

Thereafter, during a predetermined inspection measurement time (for example, 30 minutes) based on the capacity of the underground tank to be inspected, the inspection pressure value P ₀ is pressurized and sealed based on the measurement output of the pressure measuring device. The change in pressure of the gas phase in the underground tank over time is monitored, and leakage of the gas phase in the underground tank is determined based on the state of the change in pressure over time (in this case, the pressure decrease change) (Fig. _{10, T} 4).

For example, when the capacity of the underground tank to be inspected is 10 kL or less, the leakage judgment processing of the gas phase portion in the underground tank based on the state of the pressure change with time is as shown in Expression (1) and Expression (2). When the equation (2) is satisfied, it is determined that “the underground tank is normal (the gas phase portion in the underground tank is not leaked)”.
ΔP = P ₁₅ −P ₃₀ formula (1)
P _15: the pressurized to test pressure value P _0, 15 minutes the pressure P of the gas phase portion in the underground tank after _30: since pressurized to test pressure value P _0, underground after 30 minutes Pressure in gas phase in tank • (ΔP / P ₀ ) × 100 ≦ 2 [%] Formula (2)

Although not described here, the pressure state of the gas phase in the underground tank is set to a predetermined reduced pressure state (a negative pressure state of 2 kPa) with respect to the atmospheric pressure, and the underground tank is hermetically held, and then the inside of the underground tank In the case of the micro decompression inspection for determining the presence / absence of leakage from the change in the pressure of the gas phase portion over time, a micro decompression device is used instead of the micro pressurization device, and the gas phase portion of the underground tank is set to a predetermined inspection pressure value P ₀ ′ (however, in this case, the inspection pressure value P ₀ ′ is a negative pressure value). Even in this case, the operation of the pressure reducing device and the on-off valve is the same as in the case of the slightly pressurized test.

JP-A-8-198398

By the way, in the conventional leakage inspection as described above, in the fine pressure reduction process up to the inspection pressure value P ₀ ′ in the fine pressure reduction inspection, the fine pressure reduction process up to the inspection pressure value P ₀ of the underground tank in the fine pressure inspection is performed. However, the pressure adjustment work was troublesome.

The operator while monitoring the pressure measuring unit, supply passageway by operating the (exhaust path) off valve which is halfway provided, pressure test pressure value of the gas phase portion in the underground tanks P _{0 (P 0} ' ) Is adjusted so that the pressure is maintained.

However, the shape of the underground tank, the arrangement of pipes connected to the tank, the arrangement of pressure measuring devices, and the like differ for each underground tank to be inspected, and the capacity of the gas phase portion differs for each inspection. Therefore, the work of setting and maintaining the pressure in the gas phase portion in the underground tank at the inspection pressure value P ₀ (P ₀ ′) requires consideration to such an inspection environment, and is a troublesome work requiring skill. .

On the other hand, the leak inspection apparatus, whether it is a micro-pressure test or a micro-decompression test, the pressure in the gas phase in the underground tank is a predetermined test pressure value P ₀ (P ₀ ′) or a predetermined value in the vicinity thereof. When the value is reached, the control configuration starts to measure the change in pressure over time, and performs a leakage determination process for the gas phase portion in the underground tank based on the measurement result.

As a result, for example, the on-off valve is not at the inspection pressure value P ₀ (P ₀ ′) depending on the above-described fine pressure adjustment operation or fine pressure adjustment operation of the gas phase portion in the underground tank. If the valve closes early, or if the measured value measured by the pressure measuring device reaches the inspection pressure value, and the operation delay occurs even if the on / off valve is closed, the underground An excess or deficiency with respect to the inspection pressure value P ₀ (P ₀ ′) occurs in the pressure state of the gas phase portion in the tank.

In such a case, the leakage inspection apparatus determines that an accurate leakage determination cannot be made because the inspection pressure values P ₀ and P ₀ ′ are excessive or insufficient in the pressure of the gas phase in the underground tank. There was a case where the leak determination process that was started was forcibly terminated in the middle.

  And when the forced termination of the leakage judgment process of the leakage inspection apparatus has occurred, the worker must perform the above-described fine pressure adjustment work or fine pressure adjustment work of the gas phase part in the underground tank again from the beginning, Since the leakage determination processing of the leakage inspection apparatus has to be executed, the inspection work time is prolonged and the inspection work throughput is not improved.

  The present invention has been made in view of the above-described problems, and allows a worker to easily and reliably perform a fine pressure adjustment operation or a fine pressure reduction adjustment operation for an inspection pressure value of a gas phase portion in an underground tank. In addition, an object of the present invention is to provide a leakage inspection apparatus that suppresses an increase in inspection work time and improves the inspection work throughput.

  In order to solve the above-described problem, the underground tank leakage inspection apparatus according to the present invention is configured such that when the pressure measurement value of the gas phase portion in the underground tank reaches a predetermined pressure corresponding to the inspection pressure value. Thus, the first feature is that it is possible to determine whether or not it is possible to shift to the leakage determination process before starting the leakage determination process.

  In addition, the underground tank leakage inspection apparatus of the present invention guides the optimum opening / closing operation amount of the opening / closing means in consideration of different pressurization or decompression adjustment work situations for each underground tank to be inspected or for each inspection. What has been made possible is the second feature.

  For this purpose, the underground tank leakage inspection apparatus of the present invention is connected to the underground tank, and pressurizing / depressurizing means for making the pressure state in the underground tank a pressurized state or a depressurized state; An opening / closing means provided in a communication path with the means for communicating / blocking the communication path; a pressure measuring means for measuring a pressure in the underground tank; an operation of the pressurizing / depressurizing means and an opening / closing of the opening / closing means. Based on the measurement output of the pressure measuring means, the pressure change over time in the underground tank that has been pressurized or depressurized by the operation and then closed and held at a predetermined inspection pressure by the closing operation of the opening / closing means is monitored. Leakage inspection means for determining leakage of an underground tank based on the state of the pressure change over time, and a leakage inspection device for an underground tank, the lower limit pressure value including the predetermined inspection pressure value within the range And Storage means for storing a confirmation pressure range defined by an upper limit pressure value; in the pressure adjustment process in the underground tank with respect to the predetermined inspection pressure by the operation of the pressurizing / depressurizing means and the opening / closing operation of the opening / closing means A pressure confirmation detection means for detecting that the pressure in the underground tank has exceeded a first threshold value in the range smaller than the upper limit value of the confirmation pressure range; and an elapsed time from the detection time of the pressure confirmation detection means; Time measuring means for timing; preliminary determination time detecting means for detecting, based on the time measured by the time measuring means, that the elapsed time from the detection by the pressure confirmation detecting means has reached a predetermined preliminary determination time; An inspection start preliminary determination unit that determines whether or not the pressure in the underground tank is within the confirmation pressure range when the preliminary determination time is detected by the preliminary determination time detection unit; Inspection start determination means for detecting that the elapsed time from the determination within the confirmation pressure range by the inspection start preliminary determination means has reached a predetermined inspection start determination time; and the inspection start determination time of the inspection start determination means Inspection start determination means for determining whether or not the inspection can be started based on whether or not the pressure in the underground tank is equal to or higher than a second threshold value within the confirmation pressure range at the time of detection. The inspection means starts monitoring the change in pressure over time in the underground tank for leakage determination by a determination output indicating that inspection can be started from the inspection start determination means.

  The underground tank leakage inspection apparatus according to the present invention further includes a status display means for displaying the progress of work on the screen; and based on the pressure in the underground tank measured by the pressure measuring means, And an optimum opening / closing operation amount calculating means for calculating an optimum opening / closing operation amount of the opening / closing means corresponding to the pressure state, wherein the state display means displays the pressure measurement as a screen display of a pressure adjustment process state. The pressure change state in the pressure adjustment process based on the pressure in the underground tank measured by the means; and the optimum opening / closing action amount of the opening / closing means calculated by the optimum opening / closing action amount computing means; It is displayed.

  According to the present invention, in the comparison between the pressure increase or decrease state of the liquid phase in the underground tank and the first and second threshold values, the leak inspection apparatus can It is possible to determine whether or not the leakage determination process can be started, and when it is determined that the leakage determination process cannot be started, the leakage determination process is not started, so that the gas phase portion in the underground tank is slightly pressurized. The adjustment work or fine decompression adjustment work can be carried out quickly and again, and it is possible to check the sealed state of the sealed part of the underground tank and shift to another detailed inspection process. Time is suppressed and the throughput of inspection work can be improved.

  Further, according to the present invention, the state display means for displaying the work progress state on the screen further displays the current underground tank while the fine pressure adjustment work or the fine pressure adjustment work of the gas phase portion in the underground tank is being performed. The optimum opening / closing operation amount of the opening / closing means corresponding to the pressure state can be guided and displayed, so that the operator operates the opening / closing means according to the optimum opening / closing operation amount displayed by the guidance. The probability that the pressure in the gas phase part of the underground tank can be accurately set and maintained at the inspection pressure value without reconsidering the fine pressurization adjustment work or the fine decompression adjustment work without detailed consideration of the inspection environment state is increased. The fine pressure adjustment work or the fine pressure reduction work becomes easy.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of an underground tank leakage inspection apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a leakage inspection system using an underground tank leakage inspection apparatus according to an embodiment of the present invention.

  This leakage inspection system shows an example in which the leakage inspection apparatus 1 according to an embodiment of the present invention is applied to a leakage inspection apparatus for an underground tank 10 of a gas station for supplying fuel to a vehicle or the like.

  In FIG. 1, the underground tank 10 is buried in the ground, and a suction pipe 11, an oil supply pipe 13, a ventilation pipe 15, and a measuring pipe 17 are connected to the underground tank 10.

  The suction pipe 11 is for supplying the fuel stored in the underground tank 10 to the measuring device 60, and communicates with the liquid phase portion L in the underground tank 10. Is provided.

  The injection pipe 13 is for supplying fuel into the underground tank 10 from a tank or the like of a tank lorry vehicle, and the oil filling port 14 is sealed during normal times when fuel injection from the tank lorry vehicle is not received.

  The vent pipe 15 undergoes a pressure change in the underground tank 10 such as when fuel is sucked from the underground tank 10 by a pump (not shown) inside the weighing machine 60 or when fuel is injected from the tank truck into the underground tank 10. Even in such a case, the pressure in the underground tank 10 is maintained at atmospheric pressure, and an opening / closing valve 16 is provided in the middle thereof. The opening / closing valve 16 is closed when performing a leak test.

  The measuring tube 17 is inserted with a measuring rod for measuring the amount of remaining fuel in the underground tank 10 during daily inspection, and the insertion port is usually sealed with a lid. The measuring pipe 17 is used to connect a detection joint 40 described later to the underground tank 10.

Next, the configuration of the inspection unit 20 will be described.
In the case of this example, the inspection unit 20 is provided with a micro-decompression inspection means 21, a micro-pressure inspection means 22, and a pressure inspection means 23 according to the inspection method, and any one of these inspection means Are connected to the measuring pipe 17 via the on-off valve 30 and the detection joint 40. It should be noted that the connection between the micro-depressurization inspection means 21, the micro-pressure inspection means 22, the pressurization inspection means 23, and the measuring pipe 17 is not normally made, and an operator at the time of leak inspection of the underground tank 10 is not made. Is to be done manually.

  The micro decompression inspection means 21 is composed of the micro decompression means 24, the on-off valve 30, the detection joint 40, and the pressure transmitter 50, and is maintained for a certain period of time in a state where the inside of the underground tank 10 is slightly decompressed (2 kPa). The presence or absence of leakage is confirmed by measuring the time-dependent pressure change (pressure rise change).

  The fine pressure reducing means 24, the on-off valve 30, the detection joint 40, and the measuring pipe 17 are connected to each other by connection hoses 25 and 26, and the connection hose 25 is driven by driving the exhaust pump in the fine pressure reducing means 24. The gas in the underground tank 10 is sucked in through 26, and the inside of the underground tank 10 is depressurized.

  The pressure transmitter 50 is connected to the detection joint 40 via the connection hose 27, thereby detecting the pressure in the underground tank 10, and detecting the detected pressure data via the cable 51 and the interface 52. The data is transmitted to the control unit 2.

  The detection joint 40 is provided with a thermometer 41, and the temperature of the gas phase portion in the underground tank 10 is detected by the thermometer 41.

  The fine pressurization inspection means 22 encloses nitrogen gas in the underground tank 10 and slightly pressurizes it (2 kPa), and measures the pressure fluctuation over time (change in pressure drop) for a certain period of time, thereby measuring the air in the underground tank 10. This is to confirm the presence or absence of leakage at the phase part. Specifically, it is characterized in that a fine pressurizing means 28 is provided instead of the fine decompression means 24 of the fine decompression inspection means 21.

  The fine pressurizing means 28 supplies the nitrogen gas supplied from the nitrogen gas container via the connection hose and the pressure reducing valve to the inside of the underground tank 10 via the connection hose 25, the on-off valve 30, the detection joint 40, and the connection hose 26. The underground tank 10 is pressurized.

  Then, the pressure in the underground tank 10 slightly pressurized by the slightly pressurizing means 28 is detected by the pressure transmitter 50, and the pressure detected by the pressure transmitter 50 is sent to the control unit 2 as pressure data. It is supposed to be transmitted.

  The pressure inspecting means 23, after extracting all the oil liquid in the underground tank 10, pressurizes by filling the underground tank 10 with nitrogen gas, for example, and maintains the pressurized state at a predetermined test pressure or maximum normal pressure. The presence or absence of leakage is confirmed by measuring the pressure fluctuation over time (change in pressure drop) over a certain period of time. Specifically, a pressurizing unit 29 is provided instead of the microdepressurizing unit 24 of the microdepressurizing inspection unit 21 and the micropressurizing unit 28 of the micropressure inspecting unit 22.

  The pressurizing means 29 is, for example, a nitrogen gas container in which nitrogen gas is stored in a high pressure state. The high pressure nitrogen gas in the nitrogen gas container is connected to the connection hose 25, the on-off valve 30, the detection joint 40, and the connection hose 26. The inside of the underground tank 10 is pressurized by being supplied into the underground tank 10 via.

  When nitrogen gas is supplied from the nitrogen gas container, the pressure in the underground tank 10 at this time is detected by the pressure transmitter 50, and the pressure detected by the pressure transmitter 50 is the pressure data. Is transmitted to the control unit 2 as follows.

In this example, in the fine decompression inspection means 21, the fine pressurization inspection means 22, and the pressurization inspection means 23, supply or stop of decompression or pressurization to the underground tank 10 is interposed in the connection hose 25. The operator opens and closes the opening / closing valve 30, but instead, the operator may drive / stop the fine decompression means 24, the fine pressurization means 28, and the pressurization means 29. Good.
For example, the control unit 2 can input various operation inputs from the operation unit 3 including designation of any of the above-described micro decompression inspection, micro pressurization inspection, and pressurization inspection, and the pressure transmitter 50 supplied via the interface 52. Based on the measurement output (pressure data), based on the corresponding inspection processing program and inspection data stored in the storage means 4, the current pressure of the gas phase portion G in the underground tank 10 and the calculation calculation process of the temporal pressure change , A series of leak inspection processes including the leak determination process described with reference to FIG. 10, and the optimal opening / closing of the on-off valve 30 during the pressure adjustment operation for the inspection pressure value P ₀ of the gas phase portion G in the underground tank 10 described later. Various processes such as a calculation process of the closing operation amount, a display process using the display device 5 regarding the processing results and work guidance for the user are executed. The control unit 2 is constituted by a personal computer together with the operation unit 3, the storage unit 4, and the display device 5, for example.

Next, the leakage inspection apparatus 1 according to the present embodiment is used for performing the leakage determination process in the leakage inspection process, taking as an example the case where the leakage inspection apparatus 1 is used for the leakage inspection by the fine pressure inspection of the gas phase portion G in the underground tank 10. to, the slight pressure adjustment to test pressure value P ₀ the pressure of the gas phase portion G in the underground tank 10 will be described with reference to FIG.

  FIG. 2 is an explanatory diagram of the pressure state of the gas phase portion in the underground tank during the fine pressurization adjustment operation with respect to the inspection pressure value at the time of the fine pressurization inspection.

  FIG. 2 shows an underground tank in the “pressurization time (during slight pressurization adjustment work)” section shown in FIG. 10 calculated and calculated by the control unit 2 based on the measurement output of the pressure transmitter 50. 10 shows the change with time of the actual pressure state of the gas phase part G in the cylinder 10.

In the figure, P _0S indicates a preset inspection pressure value P ₀ (2 kPa) for performing the leakage determination process of the gas phase portion G in the underground tank 10, and the pressure value “0” indicates atmospheric pressure.

  Further, the time “t0” is the head of the “pressurization time” section shown in FIG. 10, that is, the atmosphere in the underground tank 10 and the pipes 11, 13, 15, and 17 communicating with the underground tank 10 at the start of pressurization. Is a state in which it is confirmed that is in a stable state (equilibrium state). For this reason, the inside of the underground tank 10 is already separated from the atmosphere outside the underground tank 10 and is in a sealed state.

In this sealed state, the user performs the operation of supplying the sealed gas to the gas phase portion G in the underground tank 10 such as the operation of starting the supply of the sealed gas (nitrogen gas) by the fine pressurizing means 28 and the opening operation of the on-off valve 30. To start pressurization of the gas phase portion G in the underground tank 10. And the gas-phase part G in the underground tank 10 based on the pressure data from the pressure transmitter 50 displayed on the display device 5 so that the pressure of the gas-phase part in the underground tank becomes a predetermined inspection pressure value _POS. While confirming the measured output of the pressure state, pressurize.

Then, a pressure P _G inspection pressure value P _0S nearby gas phase G of the underground tank 10, so that the pressure of the gas phase G of the underground tank 10 does not become over-pressurized relative to the examination pressure value P _0S Further, the pressure is further gradually increased while adjusting the valve opening amount of the on-off valve 30.

Thereafter, when the measurement output of the pressure transmitter 50 reaches the inspection pressure value P _{0 S} , the operator closes the on-off valve 30 to stop the filling of the filled gas, and the gas phase portion in the underground tank 10 is stopped. The fine pressurizing means 28 is separated from the underground tank 10 while keeping G airtight.

However, for example, when the opening and closing valve 30, as had closed based on a measurement of the transient test pressure value P _0S by the pressure transmitter 50, also is measured by the pressure transmitter 50 test pressure value P _0S If such is closing operation delay of the opening and closing valve 30 when it becomes occurs and, when the pressure P _G in the gaseous phase G of the underground tank 10 is in the close examination pressure value P _0S, on-off valve 30 the valve opening amount when the adjustment is less was as such a pressure P _G in the gaseous phase G of the underground tank 10, becomes as shown by the line ABC 'or line ABC "in FIG. 2, the inspection Excess or deficiency with respect to the pressure value P _0S occurs in advance as an error.

Therefore, leakage inspection apparatus 1 of this embodiment, in the storage means 4, comprising in the range of test pressure value P _0S, the check pressure range W which is defined by the lower limit pressure value P _0L and the upper limit pressure value P _0H The preliminary determination time t _B (= t2 to t3) and the inspection start determination time t _S (= t3 to t4) are stored. Furthermore, the leakage inspection apparatus 1 according to the present embodiment stores the first threshold value P _S1 within the range smaller than the upper limit value P _0H of the confirmation pressure range and the second threshold value within the confirmation pressure range. In the example shown in FIG. 2, P _0S (= P _S1 ) and P _0S (= P _S2 ) are stored as the threshold value P _S2 .

In addition, when performing the leakage determination process in the leakage inspection process, the control unit 2 sets the preset confirmation pressure range W (P _0L , P _0H ), the preliminary determination time t _B , and the inspection start determination time t _S. , Based on the first threshold value P _S1 and the second threshold value P _S2 , an inspection start transition confirmation process as shown in FIG. 3 is performed.

FIG. 3 is a flowchart of the inspection start transition confirmation process.
3, the control unit 2, based on the measurement output of the pressure transmitter 50, from time to time or constantly measures the pressure conditions P _G of the gas phase portion G of the underground tank 10 (step S10, S20).

Then, the control unit 2 determines that the pressure state P _G of the gas phase part G in the underground tank 10 based on the measurement output of the pressure transmitter 50 is the first threshold value P _S1 , that is, the inspection pressure value P _{0S in} this case. (Step S30). Control unit 2, measurement of the if the pressure state _{P G} underground tank 10 exceeds the test pressure value _{P 0S,} resets start the timer (step S40), the preliminary judgment time _t B (= t2 to t3) Is started (step S50). In contrast, the control unit 2, if the pressure state P _G underground tank 10 does not exceed the first threshold value P _{S1 (test} pressure value P _0S), repeats the processing in step S30, the operator equal waits for adjusting the pressure state P _G of the gas phase G of the underground tank 10 again and do not migrate to the inspection process as it stands.

On the other hand, if the controller 2 has timed the preliminary determination time t _B (= t2 to t3) (step S50), the control unit 2 finishes counting the preliminary determination time t _{B by} the timer, and the pressure state in the underground tank 10 P _G is confirmed pressure range _{W (P 0L,} P _0H) confirms whether there in (step S60).

Then, the control unit 2, the pressure state _{P G} underground tank 10 to check the pressure range _{W (P 0L,} P _0H) when within resets start the timer, this time test start judgment time _t S ( = T3 to t4) is started (step S70). In contrast, the control unit 2, the control unit 2, when the pressure state P _G underground tank 10 is gone departing from the check pressure range W is repeated the processing of step S30, the operator again equal waits for adjusting the pressure state P _G of the gas phase G of the underground tank 10, does not shift to the inspection process as it stands.

On the other hand, if the control unit 2 has timed the inspection start determination time t _S (= t3 to t4) (step S80), the control unit 2 ends the time measurement of the inspection start determination time t _{S by} the timer, and the inside of the underground tank 10 pressure condition P _G is a second threshold P _S2, i.e. in this case checks whether exceeds the check pressure value P _0S (step S90). The control unit 2, if the pressure state P _G underground tank 10 exceeds the test pressure value P _0S, exit the test start determination time t _S by the timer, the process proceeds to the inspection process (step S100). In contrast, the control unit 2, if the pressure state P _G underground tank 10 does not exceed a second threshold P _{S2 (test} pressure value P _0S), repeats the processing in step S30, the operator equal waits for adjusting the pressure state P _G of the gas phase G of the underground tank 10 again and do not migrate to the inspection process as it stands.

  As described above, the control unit 2 can perform the inspection start transition confirmation process before shifting to the inspection process, so that the inspection work time can be suppressed and the throughput of the inspection work can be improved. it can.

In the inspection start transition confirmation process shown in FIG. 3, the same inspection pressure value P _0S is applied as the first threshold value P _S1 and the second threshold value P _S2 . In this case, it is also possible to narrow the confirmation pressure range W itself by setting the lower limit pressure value P _0L itself of the confirmation pressure range W to the inspection pressure value P _0S . Moreover, it is also possible to apply the lower limit pressure value P _0L itself of the confirmation pressure range W as the first threshold value P _S1 .

In any case, since the transition to the inspection process is confirmed including a plurality of timing elements such as the preliminary determination time t _B and the inspection start determination time t _S , for example, the on-off valve 30 is connected to the pressure transmitter. 50 temporarily when checking the pressure value as had closed operation based on the measurement of P _0S and a of, also off valve 30 when the measured value P _G by the pressure transmitter 50 becomes the inspection pressure value P _0S Even if there is a delay in the closing of the valve, it will not proceed to the leak judgment process as it is, and the transition to the leak judgment process will be restricted, so the leak judgment result will be unified between each inspection. It will be highly accurate and accurate.

  4 to 6 are explanatory diagrams of a state confirmation window of the inspection start transition confirmation process displayed on the display screen of the display device during the above-described inspection start transition confirmation process.

  Furthermore, in the leakage inspection apparatus 1 according to the present embodiment, the state confirmation window 70 is displayed on the display screen of the display device 5 by the control unit 2 while the above-described inspection start transition confirmation process is being executed.

  The state confirmation window 70 includes a pressure state progress guide unit 71 and a sealed gas operation amount guide unit 72.

The pressure state progress guide 71 is a pressure of the gas phase portion G supplied from the pressure transmitter 50 after the operation of supplying the sealed gas to the gas phase portion G in the underground tank 10 is started (after t0 in FIG. 2). state, as seen changes over time in (pressure value) P _G, the pressure value P _G in the gas phase G corresponding to each the passage of time, and is graphically displayed by the control unit 2. The pressure value P _G of the gas phase G is based on the measurement values P _G that is needed supplied to the control unit 2 from the pressure transmitter 50.

  In the illustrated example, the filling operation amount guide unit 72 sets the supply amount of the filling gas per unit time of the fine pressurizing means 28 as the maximum filling capability of the fine pressurizing means 28 to 100%, that is, the current filling progress state, i.e., fine. In the pressurization progress state, it is configured to display a bar graph as to what percentage of the capacity of the sealed gas is appropriately sealed. That is, the optimum opening / closing operation amount of the on-off valve 30 in the above-described leakage inspection apparatus 1 is guided.

  In order to obtain the optimum opening / closing operation amount, the control unit 2 calculates the optimum opening / closing operation amount calculating means for calculating the optimum opening / closing operation amount of the on-off valve 30 corresponding to the current pressure state in the underground tank 10. As a function.

  In this case, the control means 2 calculates the optimum opening / closing operation amount as the optimum opening / closing operation amount calculating means, for example, as follows.

That is, the control unit 2, based on the measured value P _G that is needed supplied to the control unit 2 from the pressure transmitter 50, and the pressure state P _G in the current underground tank 10, the current pressure of underground tank 10 rate of change of the pressure conditions in the state P _G is obtained sequentially. In this embodiment, the achievement for the test pressure value P _0S pressure conditions P _G in the current underground tank 10, and the rate of change of the pressure state P _G in the current underground tank 10, and the underground current tank 10 3's relationship with the rate of change of the rate of change of the pressure condition P _G in the underground tank 10 up to the pressure state P _G of the inner, the optimum opening and closing operation of the opening and closing valve 30, as 100% fully opened It is configured to calculate and calculate.

4-6 is a representation of the difference between the optimum opening and closing operation of the opening and closing valve 30 which is calculated according to a difference in pressure conditions P _G in the current underground tank 10 for testing pressure value P _0S .

For example, as shown in FIG. 4, from the supply beginning of fill gas into the gas phase G of the underground tank 10, the pressure state P _G of the gas phase portion G of the underground tank 10 approaches the test pressure value P _0S Up to approximately 1, the maximum opening / closing operation amount (for example, 100%) after taking a time of 1 minute or more per 1 m ^{3 of the} gas phase is displayed as the optimum opening / closing operation amount. .
Then, as shown in FIG. 5, check the pressure range _{W (P 0L,} P _0H) approaches the pressure state _{P G} underground tank 10 to the lower limit value _{P 0H} of opening and closing valves as the optimum opening and closing operation amount 30 The opening / closing operation amount of starts to decrease.

As shown in FIG. 6, when a pressure state P _G underground tank 10 to the lower limit value P _0H confirmation pressure range W, the case of this example, the open-closed-off valve 30 as the optimum opening and closing operation amount The operation amount becomes an operation amount (for example, 0%) corresponding to the valve closing state, and finally the valve closing of the on-off valve 30 is guided.

  FIG. 7 shows a state during the inspection start determination process in the inspection start shift confirmation process (the state in step S90 in FIG. 3).

  As described above, the sealed operation amount guide unit 72 can accurately check the pressure of the gas phase portion G of the underground tank 10 without re-adjusting the pressurization or depressurization without performing detailed consideration on the state of the inspection environment. The probability that it can be set and held increases.

  When the inspection start determination process in the inspection start transition confirmation process is completed and the process proceeds to the inspection (the state in step S100 in FIG. 3), the control unit 2 displays the state confirmation window 70 shown in FIG. The display is automatically switched to the inspection status window 70 shown in FIG. 6 so that the operator can understand that the inspection start transition confirmation processing has shifted to the inspection start determination processing.

  The leak inspection apparatus according to the present embodiment is as described above, but the present invention is not limited to the above-described embodiment.

  In the above-described embodiment, only the state confirmation window 70 of the inspection start transition confirmation process is shown in FIGS. 4 to 8, but the measurement monitor displayed including the state confirmation window 70 on the display screen of the display device. You may make it display on a screen.

FIG. 9 shows an embodiment of the measurement monitor screen.
In the correspondence table 91 in which the input various condition items 92 and the actual input values 93 are provided on the upper side of the state confirmation window 70 in the measurement monitor screen 90, a display corresponding to the measured pressure value in the input various condition items. The part 94 may be blinked when the actual measurement value exceeds the upper limit value. The form of blinking includes (1) blinking the numerical value itself, (2) blinking the background of the numerical value input part, and (3) blinking the entire table. In addition, an alarm sound may be generated. Further, although not shown in the figure, an electromagnetic valve is provided between the detection joint 40 and the measuring pipe 17, and when the actual measured value exceeds the upper limit value, a signal is sent to the electromagnetic valve and the pressure is automatically set. You may make it stop a raise.

  In the leakage inspection apparatus 1 according to the above-described embodiment, the inspection unit 20 is configured to include the fine decompression inspection unit 21, the fine pressurization inspection unit 22, and the pressurization inspection unit 23. Any one of these inspection means may be provided.

  Further, in the leakage inspection apparatus 1 according to the above-described embodiment, the inspection start transition confirmation process has been described by taking the case of the fine pressurization inspection process as an example, but the above described also in the case of the fine decompression inspection process and the pressurization inspection process. Needless to say, the present invention can be easily applied by appropriately changing various setting values including the confirmed pressure range W and the magnitude determination of the transition determination.

It is a lineblock diagram of the leak inspection system using the leak inspection apparatus of the underground tank concerning one embodiment of the present invention. It is explanatory drawing of the pressure state of the gaseous-phase part in an underground tank in the fine pressurization adjustment operation | work with respect to a test | inspection pressure value in the case of a pressurization test | inspection. It is a flowchart of the inspection start transfer confirmation process which the control part of the leakage inspection apparatus of this Embodiment performs. It is explanatory drawing of the state confirmation window of the inspection start transfer confirmation process displayed on the display screen of a display apparatus. It is explanatory drawing of the state confirmation window of the inspection start transfer confirmation process displayed on the display screen of a display apparatus. It is explanatory drawing of the state confirmation window of the inspection start transfer confirmation process displayed on the display screen of a display apparatus. It is explanatory drawing of the state confirmation window of the inspection start transfer confirmation process displayed on the display screen of a display apparatus. It is the figure which showed the inspection state window. An example of a measurement monitor screen is shown. It is explanatory drawing about a micro pressurization test | inspection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leakage inspection apparatus 2 Control part 3 Operation part 4 Memory | storage means 5 Display apparatus 10 Underground tank 11 Suction pipe 12 Check valve 13 Injection pipe 14 Oil inlet 15 Ventilation pipe 16 On-off valve 17 Measuring pipe 20 Inspection part 21 Slightly low-pressure inspection means 22 Fine pressurization inspection means 23 Pressurization inspection means 24 Fine decompression means 25, 26, 27 Connection hose 28 Fine pressurization means 29 Pressurization means 30 On-off valve 40 Detection joint 41 Thermometer 50 Pressure transmitter 51 Cable 52 Interface 60 Meter 70 State confirmation window 71 Pressure state progress guide part 72 Enclosed operation amount guide part

Claims (4)

A pressurizing / depressurizing means connected to the underground tank to change the pressure state in the underground tank into a pressurized state or a depressurized state;
An opening / closing means provided in a communicating path between the underground tank and the pressurizing / depressurizing means, and communicating / blocking the communicating path;
Pressure measuring means for measuring the pressure in the underground tank,
Time elapsed after the airtight holding in the underground tank that is pressurized or depressurized by the operation of the pressurizing / depressurizing means and the opening operation of the opening / closing means, and then kept at a predetermined inspection pressure by the closing operation of the opening / closing means. An underground tank leakage inspection device comprising a leakage inspection means for monitoring a pressure change based on a measurement output of the pressure measurement means and performing a leakage determination of the underground tank based on a state of the pressure change over time,
Storage means for storing a confirmation pressure range defined by a lower limit pressure value and an upper limit pressure value, including the predetermined inspection pressure value within the range;
In the process of adjusting the pressure in the underground tank with respect to the predetermined inspection pressure by the operation of the pressurizing / depressurizing means and the opening / closing operation of the opening / closing means, the pressure in the underground tank is smaller than the upper limit value of the confirmation pressure range. Pressure confirmation detecting means for detecting that a first threshold value in the range has been exceeded;
Time measuring means for measuring the elapsed time from the detection of the pressure confirmation detecting means;
Based on the time of the time measuring means, preliminary determination time detection means for detecting that the elapsed time from the detection time of the pressure confirmation detection means has become a predetermined preliminary determination time;
Inspection start preliminary determination means for determining whether or not the pressure in the underground tank is within the confirmation pressure range when the preliminary determination time is detected by the preliminary determination time detection means;
Based on the time measured by the time measuring means, an inspection start determining means for detecting that the elapsed time from the determination within the confirmation pressure range by the inspection start preliminary determining means has reached a predetermined inspection start determination time;
Whether or not inspection can be started based on whether or not the pressure in the underground tank is equal to or higher than a second threshold value within the confirmation pressure range when the inspection start determination time is detected by the inspection start determination means. An inspection start determining means for determining
With
The underground tank leakage inspection apparatus according to claim 1, wherein the inspection means starts monitoring a change in pressure with time in the underground tank for leakage determination by a determination output indicating that the inspection can be started from the inspection start determination means. The first threshold value stored in the storage means is one of a predetermined inspection pressure value and a lower limit value of a confirmation pressure range, and the second threshold value is a predetermined inspection pressure value. The leak inspection apparatus for underground tanks according to claim 1. Furthermore, it has a status display means for displaying the work progress status on the screen,
2. The state display means switches the screen display from a previous screen display of the pressure adjustment process state to a display screen of a leakage inspection state based on a determination output indicating that the inspection start is possible from the inspection start determination means. Or the underground tank leak inspection apparatus of 2 description. In addition, status display means for displaying the work progress status on the screen,
An optimal opening / closing operation amount calculating means for calculating an optimal opening / closing operation amount of the opening / closing means corresponding to the current pressure state in the underground tank based on the pressure in the underground tank measured by the pressure measuring means; With
The state display means includes, as a screen display of the pressure adjustment process state, a pressure change state in the pressure adjustment process based on the pressure in the underground tank measured by the pressure measurement means, and the optimum opening / closing operation amount calculation means. The underground tank leakage inspection apparatus according to claim 1 or 2, wherein the optimum opening / closing operation amount of the opening / closing means calculated by the step is displayed in a graph.

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