JP4309337B2 - Liquid storage device and operation method thereof - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a liquid storage device that stores a liquid having a specific gravity lower than that of water such as petroleum or LPG in an underground bedrock and stores it in a storage room (bedrock tank) and an operation method thereof.

  FIG. 1 is a diagram showing a schematic configuration of this type of conventional liquid storage device. As shown in the figure, a protective pipe 101 communicating with a storage room (rock tank) 100 provided in the underground rock is provided, and a suction pipe 102, a motor 103, a pump 104 driven by the motor 103, A pumping pipe 105 connected to the discharge port of the pump 104 and a head plate 106 provided above the protective pipe 101 are provided. The upper end of the pumping pipe 105 penetrates the head plate 106 and protrudes upward. By starting the motor 103, the pump 104 is driven, and the specification liquid 107, which is a flammable liquid sucked into the suction pipe 102, is discharged from the discharge pipe discharge port 105 a that passes through the lift pipe 105 from the discharge port of the pump 104. The liquid is sent to a predetermined place.

  In the liquid storage device having the above configuration, when an unforeseen problem such as a crack in the welded part or a pinhole opening due to some cause in the protective tube 101, the specification liquid being stored in the storage chamber 100 107 enters a dangerous state such as the outflow from the defective part to the atmosphere side or the gasified specification liquid gas is ejected. And in the worst case, it leads to ignition and explosion fire. At this time, since it is not allowed to leave the flammable specification liquid 107 in the underground large-capacity storage room 100, the bottom water (ground water) 108 is raised as shown in FIG. (Skirt) Overcoming the upper end of 109, flowing into the protective tube 101, and further rising, the specification liquid 107 being stored in the storage chamber 100 is replaced with the bottom water 108 and sealed in the protective tube 101. Safety is ensured by limiting the amount of the specification liquid 107 released to the atmosphere on the ground.

  As described above, since the method of replacing the specification liquid 107 in the storage chamber 100 with the bottom water 108 must be prepared for a long time before the replacement, a shutoff valve for blocking the specification liquid 107 flowing into the protective tube 101 is provided. An increasing number of examples are used. FIG. 3 is a diagram showing a configuration of a liquid storage device provided with this shut-off valve. As shown in the figure, a shutoff valve 110 is provided at the tip of the protective tube 101, and a seal mechanism 111 seals between the shutoff valve 110 and the protective tube 101. When the shutoff valve 110 is closed, the flow of the specification liquid 107 in the storage chamber 100 into the protective tube 101 is shut off.

  4A and 4B are diagrams showing a structure example of the shut-off valve 110. FIG. 4A is a cross-sectional view in a state where the shut-off valve 110 is open, and FIG. 4B is a cross-sectional view in a state where the shut-off valve is closed. . In the shut-off valve 110, a piston 113 is disposed at the center of a valve housing 112, and a cylinder (valve element) 114 slides up and down along the axial direction of the piston 113. A spring 115 is interposed between the piston 113 and the cylinder 114. In addition, a hydraulic passage 116 is provided at the center of the piston 113, and by supplying pressure oil from the hydraulic line 118, the cylinder 114 is pressed against the elastic force of the spring 115, and the upper end of the cylinder 114 is a valve. Separating from the seat 117, the shutoff valve 110 opens. As a result, the specification liquid 107 flows as indicated by a broken line A. The cylinder 114 for stopping the supply of the pressure oil is pushed up by the elastic force of the spring 115, the upper end thereof is in close contact with the valve seat 117, the shutoff valve 110 is closed, and the specification liquid 107 is shut off.

  FIG. 5 is a diagram showing a schematic configuration of a liquid storage device using a shut-off valve. The storage room 100 for storing the specification liquid 107 is provided with various sizes of large and small digging rocks of several tens of meters to several hundreds of meters (of course, several thousand meters are possible). It has a structure in which underground water pressure or artificial water pressure addition structure is adopted and the gasification of the specification liquid 107 is suppressed and confined in the basement. The specification liquid 107 is blocked from the ground by the water sealing pressure of the water seal 121 between the protective tube 101 and the formation 122 above the plug 120. Accidents often occur due to defects including cracks in the rock.

  In the liquid storage apparatus having the above configuration, the shutoff valve 110 is normally opened, and the specification liquid 107 is protected as shown by a broken line B through the valve portion of the shutoff valve 110 (between the cylinder 114 and the valve seat 117 in FIG. 4). The liquid is pumped by the pump 104 through the pipe 101. When an accident occurs, the shut-off valve 110 operates rapidly (within a few seconds), and the pump protection pipe 101 is closed with respect to the storage chamber 100. In this case, since the inflow of the suction liquid of the pump 104 is stopped, various operation patterns are conceivable in which the pump 104 is stopped immediately while the pump is stopped immediately, or the flow rate is throttled and discharged by controlling the flow rate or the rotational speed. What is important here is the protection of the pump 104 and the implementation of safety measures. When the emergency shut-off valve 110 is closed, the pump 104 can only be operated for a limited time in any case. Therefore, it is a problem to safely discharge the flammable specification liquid 107 in the protective tube 101. Become.

  The present invention has been made in view of the above points, and provides a liquid storage device that can safely and quickly discharge the specification liquid in the protective tube when the emergency shut-off valve is closed, and an operation method thereof. Objective.

In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a storage room for storing specification liquid arranged underground, a protective pipe communicating with the storage room, and a specification liquid in the storage room in the protective pipe. In the liquid storage apparatus comprising a pump for pumping and a pumping pipe connected to a discharge port of the pump, and a shutoff valve for shutting off the specification liquid in the storage chamber from flowing into the protective pipe When the valve is closed, a drain means is provided for discharging the specification liquid in the protective tube to the outside. The drain means sends an inert gas into the protective pipe and pressurizes the specification liquid in the protective pipe. Pressure gas , and specification liquid discharge means for discharging the specification liquid from the inside of the protective tube by pressurizing the specification liquid by the specification liquid pressurizing means, and in the gas pipe for supplying the inert gas Pressure sensor to measure the gas pressure of the gas and measure the pressure in the storage room A pressure sensor is provided that, and controlling the pressure of the inert gas supplied through the gas pipe.

According to a second aspect of the present invention, in the liquid storage apparatus according to the first aspect, the specification liquid discharge means includes a specification liquid discharge pipe for discharging the specification liquid in the protective tube to the outside, and the specification liquid discharge pipe. It is comprised from the specification liquid return piping connected and returned to the said storage chamber .

The invention according to claim 3 is a storage room for storing specification liquid disposed in the basement, a protection pipe communicating with the storage room, a pump for pumping specification liquid in the storage room in the protection pipe, In a liquid storage device that includes a pumping pipe connected to the discharge port, and a shutoff valve that shuts off the specification liquid in the storage chamber from flowing into the protective pipe, when the shutoff valve is closed, A drainage means for discharging the specification liquid in the protective tube to the outside is provided, and the drainage means includes a drainage pump different from the pump in the protection pipe, and the specification liquid in the protection pipe is provided by the drainage pump. Is configured to be delivered to the outside of the protective tube .

According to a fourth aspect of the present invention, there is provided the liquid storage device according to the first aspect, wherein the specification liquid discharge means is provided on a side wall of the protection tube and returns from a specification liquid return valve that returns the specification liquid in the protection tube to the storage chamber. It is configured .

According to a fifth aspect of the present invention, in the liquid storage device according to any one of the first to fourth aspects, the double pipe structure including an inner pipe and an outer pipe at an upper part from the storage chamber of the protective pipe is provided. An inert gas supply means for supplying an inert gas as a purge gas to the gap between the inner pipe and the outer pipe of the structure; an inert gas discharge means for discharging the inert gas from the gap; and an inert gas discharged from the gap. A specification liquid gas detection means for detecting a specification liquid gas contained in the active gas is provided. Further, a gas detection device is installed on the ground and used together with the specification liquid gas detection means to monitor gas leakage .

  The invention according to claim 8 is a storage room for storing specification liquid disposed in the basement, a protection pipe communicating with the storage room, a pump for pumping specification liquid in the storage room into the protection pipe, In the operation method of the liquid storage device, the liquid storage device including a pumping pipe connected to the discharge port and a shutoff valve for blocking the specification liquid in the storage chamber from flowing into the protective pipe. A double pipe structure having an inner pipe and an outer pipe at the upper part from the storage chamber, and an inert gas is supplied as a purge gas to the gap between the inner pipe and the outer pipe of the double pipe structure, and is discharged from the gap. The specification liquid gas contained in the inert gas is monitored, and leakage of the specification liquid gas is monitored.

The invention of claim 6 includes a stockpile chamber stockpiling disposed specifications liquid underground, the protective tube communicating with said reserve chamber, the pump and the pump for pumping specifications liquid stockpiling chamber to the protective tube A pumping pipe connected to the discharge port and a shut-off valve for blocking the inflow of flammable liquid in the storage chamber into the protective pipe, and the specified liquid level in the storage chamber is adjusted to the bottom water level. In the operation method of the liquid storage apparatus configured to be adjusted by ascending and descending, when the shutoff valve is closed, the specification liquid in the protective pipe is discharged to the outside, and the bottom water is introduced into the protective pipe, A method for operating a liquid storage device, wherein the level is set to a surface level position as much as possible.

According to the first aspect of the present invention, when the shut-off valve is closed in an emergency, the specification liquid in the protective tube is discharged to the outside by the drainage means, so the specification liquid does not exist in the protective tube. without liquid or its liquefied gas leaks, high safety can be ensured, since drainage means is composed of a specification fluid pressure means and specifications liquid discharge means, N ₂ protection tube specifications fluid pressure means A liquid whose specifications can be discharged from the inside of the protective tube to the outside of the protective tube only by supplying an inert gas such as a gas, and the inside of the protective tube can be filled with an inert gas. A stockpile device can be provided.

According to the second aspect of the present invention, the specification liquid in the protective tube is pressed by the gas pressure of N ₂ gas, and returned to the storage chamber through the specification liquid discharge pipe and the specification liquid return pipe.

According to the invention described in claim 3, since the drainage means is provided with a drainage pump different from the liquid pump in the protective tube, the drainage pump is activated even when the shutoff valve is closed in an emergency. the specification solution of protecting tube can be discharged to the protective irrigation. When an inert gas such as N ₂ gas is supplied into the protective tube along with the discharge of the specification liquid, the protective tube can be filled with the inert gas without using a high-pressure inert gas, and safety is further improved. A liquid storage device can be provided.

According to the invention described in claim 4, since the specification liquid return valve is provided on the side wall of the protective tube, the specification liquid in the protective tube can be returned directly to the storage chamber.

According to the invention described in claim 5, since the upper part of the protective pipe storage chamber is a double pipe structure having an inner pipe and an outer part, neither an inner pipe nor an outer pipe is cracked or pinholed. As long as there is no leakage of the specified liquid or the specified liquid gas, an inert gas supply means for supplying an inert gas as a purge gas to the gap between the inner pipe and the outer pipe of the double pipe structure, and the inert gas from the gap Since the inert gas discharging means for discharging and the specified liquid gas detecting means for detecting the specified liquid gas contained in the inert gas discharged from the gap are used together with the gas detecting means installed on the ground, It is possible to provide a liquid storage device with further improved safety, such as being able to monitor the leakage of the specified liquid gas at all times and easily identify the location of the gas leak .

According to the sixth aspect of the present invention, when the shutoff valve is closed, the specification liquid in the protective pipe is discharged to the outside, the bottom water is introduced into the protective pipe, and the bottom water level is set to the ground level as much as possible. Since it is in the position, it is possible to provide a method for operating the liquid storage device in which the inside of the protective tube is filled with bottom water and safety is improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 6 is a diagram showing a configuration example of the liquid storage apparatus according to the present invention. In the figure, reference numeral 10 denotes a reserve room (bedrock tank) provided by digging underground rock, and the lower end of the protective tube 12 is opened through the formation 11 from the ground into the reserve room 10. The upper end of the protective tube 12 is connected to a head plate 18 installed on the ground. A shutoff valve 14 is disposed inside the lower end of the protective tube 12, and a seal mechanism 13 is interposed between the shutoff valve 14 and the protective tube 12 for sealing. The structure of the shut-off valve 14 is the same as the shut-off valve shown in FIG. 4, for example. By opening the shut-off valve 14, the inside of the protective tube 12 and the storage chamber 10 communicate with each other, and the inside of the protective tube 12 and the stock chamber 10 are closed. Is designed to be isolated (blocked).

  A motor 15, a pump 16 driven by the motor 15, and a pumping liquid pipe 17 connected to a discharge port of the pump 16 are disposed in the protective pipe 12. The pumping pipe 17 penetrates the head plate 18, The discharge port 17 a protrudes above the head plate 18. The lower end of the protective tube 12 is surrounded by a weir (skirt) 19 having a predetermined height standing on the bottom surface of the storage chamber 10, and the specification liquid 20 and bottom water in the storage chamber 10 are passed over the upper end of the weir 19. 21 flows into the area surrounded by the skirt.

  A plug 22 considering watertightness and airtightness is provided between the upper formation 11 (including the rock) of the storage room 10 and the protective tube 12, and a water seal 23 is provided between the formation 11 above the plug 22. The specification liquid 20 is blocked from the ground (upper part of the formation 11) by the water sealing pressure of the water seal 23.

Reference numeral 24 denotes a gas pipe for supplying N ₂ gas into the protective pipe 12, and the gas pipe 24 is provided with a valve V1, and an appropriate gas pressure is supplied from an N ₂ gas source (not shown) by opening the valve V1. N ₂ gas can be supplied. Reference numeral 26 denotes a specification liquid discharge pipe for discharging the specification liquid 20 in the protective tube 12 to the outside. The upper end of the specification liquid passes through the head plate 18 and extends to the ground, and the lower end extends to the vicinity of the lower end of the protective tube 12. It is open. Reference numeral 27 denotes a specification liquid return pipe for returning the specification liquid 20 into the storage chamber 10, and the upper end of the specification liquid return pipe 27 extends to the ground and is connected to the upper end of the specification liquid discharge pipe 26 via a valve V2. . 25 is a pressure sensor for measuring the gas pressure P1 in the gas pipe 24, and 28 is a pressure sensor for measuring the pressure P2 in the storage chamber 10.

In the liquid storage apparatus having the above-described configuration, a flammable liquid having a specific gravity lighter than that of water such as petroleum or LPG is stored in the storage chamber 10 as the specification liquid 20. Normally, the shut-off valve 14 is opened, and the inside of the protective tube 12 and the storage room 10 are in communication. By starting the motor 15, the pump 16 is driven, and the specification liquid 20 is fed from the discharge port 17 a to a predetermined place through the pumping pipe 17. When the emergency shutoff valve 14 is closed, the inside of the protective tube 12 and the storage room 10 are shut off (isolated). Opening the valve V1 in this state, pressing supplies the controlled N ₂ gas pressure from the N ₂ gas source, by opening the valve V2, specifications liquid 20 of the protective tube 12 by the gas pressure of N ₂ gas Then, the liquid is returned to the storage chamber 10 through the specification liquid discharge pipe 26 and the specification liquid return pipe 27.

At this time, the pressure sensor 25 measures the gas pressure of the N ₂ gas in the gas pipe 24 and the pressure in the storage chamber 10 of the pressure sensor 28, and obtains the pressure information so that the N ₂ gas supplied through the gas pipe 24 can be obtained. Pressure control becomes easy. The pressure P1 of the N ₂ gas supplied through the gas pipe 24 generally needs to be equal to or higher than the pressure indicated by the following formula.
P1 = (saturated vapor pressure of the specified liquid)
+ (Specified liquid head corresponding to the maximum distance between the specified liquid level and the head plate position.
Pressure by)

For example, when the LPG liquid is received in the storage room 10 provided in the bedrock at a depth of 200 m underground, the pressure by the liquid head is approximately 1 MPa if the saturated vapor pressure is about 1 MPa. Therefore, the wall thickness of the protective tube 12 is about 6 mm if designed at 2 MPa in terms of pressure resistance design, which is a possible wall thickness. In the above example, the specification liquid 20 in the protective pipe 12 is returned to the storage chamber 10 through the specification liquid discharge pipe 26 and the specification liquid return pipe 27. However, the gas pipe is connected to the discharge port of the lift pipe 17 branched connecting from 17a, to supply N ₂ gas at a predetermined pressure to the liquid being pumped tube 17, a suitable design solution acceptance (not shown) specifications liquid discharged from the protective tube 12 disposed in version liquid discharge tube into the 26 You may make it accommodate in a container. Further, the specification liquid discharge pipe 26 may be connected to the specification liquid receiving pipe of the storage chamber 10. Moreover, you may provide a specification liquid supply piping so that the specification liquid discharged | emitted by the specification liquid discharge piping 26 may be supplied to another storage chamber 10 or a tank on the ground.

In order to avoid the supply of high-pressure N ₂ gas as described above, there are several further means. FIG. 7 is a diagram showing a configuration example of a liquid storage device that avoids the supply of high-pressure N ₂ gas. In FIG. 7, the parts denoted by the same reference numerals as those in FIG. 6 indicate the same or corresponding parts. In this liquid storage device, as shown in the figure, an emergency drain pump 29 is provided in the protective tube 12, and a specification liquid discharge pipe 26 is connected to the discharge port of the emergency drain pump 29. Reference numeral 30 is a specification liquid discharge pipe branched from the specification liquid return pipe 27, and the specification liquid discharge pipe 30 is provided with a valve V3.

In the liquid storage apparatus having the above-described configuration, when the emergency shut-off valve 14 is closed and the inside of the protective tube 12 and the storage chamber 10 are isolated, the valve V1 and the valve V2 are opened and the valve V3 is closed and the emergency drain pump 29 , The specification liquid 20 in the protective tube 12 is returned to the storage chamber 10 through the specification liquid discharge pipe 26 and the specification liquid return pipe 27 by the emergency drain pump 29. The protective pipe 12 from which the specification liquid 20 has been discharged is filled with N ₂ gas through the gas pipe 24.

  8 and 9 are diagrams showing another configuration example of the liquid storage apparatus according to the present invention. 8 and 9, the parts denoted by the same reference numerals as those in FIGS. 6 and 7 indicate the same or corresponding parts. As shown in the figure, this liquid storage device is a specification liquid for returning the specification liquid 20 in the protective tube 12 to the storage chamber 10 when the emergency shut-off valve 14 is closed and the protective tube 12 and the storage chamber 10 are isolated. A return valve 31 is provided. As shown in FIG. 9, the specification liquid return valve 31 includes a valve seat 31-2 and a valve body 31-3 fixed to the tip of a specification liquid return pipe 31-1 communicating with the protective tube 12. Yes. One end of a plurality of rods 31-4 is fixed to the valve body 31-3, the rod 31-4 passes through a through hole provided in the valve seat 31-2, and the other end is elastically applied by a spring 31-5. It is always urged toward the protective tube 12 side. An annular seal member 31-6 is provided on the surface of the valve seat 31-2 on the valve body 31-3 side. The specification liquid return valve 31 is always closed when the valve body 31-3 is pulled toward the valve seat 31-2 by the elastic force of the spring 31-5 and is in close contact with the seal member 31-6. It is in a state.

In the liquid storage device having the above configuration, when the shutoff valve 14 is closed and the inside of the protective tube 12 and the storage chamber 10 are isolated in an emergency, the valve V1 is opened and pressure N ₂ gas is supplied from the N ₂ gas source through the gas pipe 24. Then, the inside of the protective tube 12 is pressurized. Specification in the storage chamber 10 where the internal pressure of the protective tube 12 rises and the hydraulic pressure of the specification liquid 20 applied to the surface of the valve body 31-3 of the return valve 31 on the protective tube 12 side is applied to the outer surface of the valve body 31-3. When the hydraulic pressure of the fluid 20 + the elastic force of the spring 31-5 is exceeded, the valve body 31-3 is separated from the valve seat 31-2 (seal member 31-6), and the valve seat 31-2 and the valve body 31-3 are separated. As shown by the broken line C, the specification liquid 20 in the protective tube 12 returns to the storage chamber 10 through the gap. As a result, the specification liquid 20 in the protective tube 12 can be returned directly into the storage chamber 10.

In the above example, the case where the return valve 31 is provided separately from the shut-off valve 14 has been described, but when the shut-off valve 14 having the structure shown in FIG. 4 is used, N ₂ gas is supplied into the protective tube 12. When the specified hydraulic pressure in the protective tube 12 applied to the inside of the cylinder 114 exceeds the hydraulic pressure of the specified liquid 20 in the storage chamber 10 applied to the outside of the cylinder (valve body) + the elastic force of the spring 115, The cylinder 114 is separated from the valve seat 117, and the specification liquid 20 in the protective tube 12 can be returned directly into the storage chamber 10. In this case, regardless of the depth of the storage room 10 now, the maximum difference between the specification liquid 20 level in the storage room 10 and the specification liquid 20 level in the protective tube 12 is 50 m (usually a storage room (bedrock provided in the basement bedrock) If the height of the tank 10 is about 50 m), this amount is 0.25 MPa. Therefore, it is sufficient to design the elastic force of the spring 115 of the shutoff valve 14 so that it can be pressurized with N ₂ gas to −0.25 MPa. Conversely, the N ₂ gas pressure that overcomes the absolutely necessary elastic force of the spring 115 may be calculated.

6 to 8, when the emergency shutoff valve 14 is closed and the protective tube 12 and the storage chamber 10 are isolated, the specification liquid 20 in the protective tube 12 is excluded. By injecting N ₂ gas into the protective tube 12, the atmosphere in the protective tube 12 becomes inactive with the N ₂ gas, and it is also expected to dilute the specification liquid gas leaking from the protective tube 12 to the outside. There is also a merit that safety is further improved.

FIG. 10 is a diagram showing another configuration example of the liquid storage apparatus according to the present invention. 10, parts denoted by the same reference numerals as those in FIGS. 6 to 9 indicate the same or corresponding parts. As shown in the figure, the liquid storage device has a double pipe structure in which an outer pipe 37 is provided so as to surround the outer portion of the protective pipe 12 penetrating the formation 11. Then, N ₂ gas is supplied as a purge gas through a purge gas supply pipe 32 having a valve V4 in the gap between the double structure outer pipe 37 and the protective pipe 12 corresponding to the inner pipe. One end of the purge gas discharge pipe 34 is opened in the gap between the outer pipe 37 and the protective pipe 12, and the other end of the purge gas discharge pipe 34 projects upward through the head plate 18, and a valve V5 is provided in the middle. ing.

  In addition, a water seal 23 is provided between the formation (including the rock) 11 of the outer tube 37 above the plug 22, and the specification liquid is blocked from the ground by the water seal pressure of the water seal 23. It has become. 33 is a pressure sensor for detecting the internal pressure of the purge gas supply pipe 32, and 35 is a pressure sensor for detecting the internal pressure of the purge gas discharge pipe 34. Reference numeral 36 denotes a gas detection device.

In the liquid storage apparatus having the above-described configuration, when the emergency shutoff valve 14 is closed and the inside of the protective tube 12 and the storage chamber 10 are isolated, the valve V1 and the valve V2 are opened, and the valve V3 is closed to thereby close the inside of the protective tube 12 The specification liquid 20 is pressurized by N ₂ gas supplied through the gas pipe 24, and the specification liquid 20 is returned to the storage chamber 10 through the specification liquid discharge pipe 26 and the specification liquid return pipe 27. The N ₂ gas is sealed in the protective tube 12 from which the specification liquid 20 has been discharged, as in the case of FIG.

By adopting a double structure in which the upper part of the protective tube 12 is surrounded by the outer tube 37 as described above, even if either the protective tube 12 or the outer tube 37 is damaged, the specification liquid gas does not leak and safety is ensured. Will improve. Further, the valve V5 is always opened, the valve V4 is opened, and N ₂ gas is supplied as a purge gas to the gap between the outer tube 37 and the protective tube 12 at a predetermined pressure. At this time, the gap pressure is monitored by the pressure sensor 35. Further, the N ₂ gas in the gap between the outer tube 37 and the protective tube 12 is sent to an external processing facility through the purge gas discharge pipe 34. The specification liquid gas of N ₂ gas passing through the purge gas discharge pipe 34 is detected by the gas detection device 36, and the specification liquid gas and the amount leaking into the gap between the outer pipe 37 and the protective pipe 12 are constantly monitored.

Established the gas detection apparatus 36 for detecting the specifications liquid gas on the ground, when to detect the specification liquid gas leaking from the protective tube 12, if it can not find a specification liquid gas leaking due to external factors such as wind direction However, by adopting the method of detecting the specification liquid gas in the N ₂ gas passing through the purge gas discharge pipe 34 as described above, the gap between the outer pipe 37 and the protective pipe 12 is not affected by external factors. It is possible to detect the specification liquid gas leaking into the tank. The double pipe and the purge gas supply mechanism can also be employed in the liquid storage apparatus having the configuration shown in FIGS.

Further, if a gas detection device 36 for detecting the specification liquid gas in the N ₂ gas passing through the purge gas discharge pipe 34 and a gas detection device installed on the ground are used in combination, the location of the gas leak can be easily identified. For example, when the specification liquid gas is detected by the gas detector installed on the ground even though the specification liquid gas is not detected by the gas detection device 36, for example, the bedrock other than the protective pipe is cracked. Further, when the specification liquid gas is detected by the gas detection device 36 and the gas detection device installed on the ground, both the protective tube 12 and the outer tube 37 are cracked. Further, it is understood that the protective tube 12 is cracked when the gas detection device 36 detects the specification liquid gas but the ground gas detection device does not detect the specification liquid gas.

  The double pipe structure is technically possible except for the cost. A double structure can be easily formed by combining an appropriate flange and an expansion / contraction mechanism without using a welded structure. In addition, when the shutoff valve 14 is operated for safety reasons, it should be considered that the level of the bottom water 21 is raised and the specification liquid in the dam 19 is replaced with the bottom water 21.

Even if the N ₂ gas supplied from the gas pipe 24 into the protective pipe 12 is low by raising the level of the bottom water 21 to raise the specification liquid (generally lighter than water), the specification liquid return valve 31 and the shut-off valve 14 And the specification liquid 20 in the protective tube 12 can be pushed up to near the ground surface. In this case, the lower end of the specification liquid discharge pipe 34 is opened in the protective pipe 12 near the surface of the earth, so that the inside of the protective pipe 12 is replaced with the bottom water 21. Therefore, the atmosphere inside the protective pipe is very safe. It can be.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. For example, the specification liquid stored in the storage room (rock tank) is not limited to petroleum or LPG, and can naturally be used for storing liquid having a specific gravity smaller than that of water. Further, the inert gas to pressurize the protective tube specifications solution, although an example of using the N ₂ gas as a purge gas for double pipe structure, any inert gas, but is not limited to the N ₂ gas.

It is a figure which shows the schematic structural example (normal use condition) of the conventional liquid storage apparatus. It is a figure which shows the schematic structural example (state which substituted the specification liquid with the bottom water) of the conventional liquid storage apparatus. It is a figure which shows the schematic structural example of the liquid storage apparatus provided with the conventional cutoff valve. It is a figure which shows the structural example of a cutoff valve. It is a figure which shows the structural example of the liquid storage apparatus provided with the conventional cutoff valve. It is a figure which shows the schematic structural example of the liquid storage apparatus provided with the cutoff valve which concerns on this invention. It is a figure which shows the schematic structural example of the liquid storage apparatus provided with the cutoff valve which concerns on this invention. It is a figure which shows the schematic structural example of the liquid storage apparatus provided with the cutoff valve which concerns on this invention. It is a figure which shows the structural example of a specification liquid return valve. It is a figure which shows the schematic structural example of the liquid storage apparatus provided with the cutoff valve which concerns on this invention.

Explanation of symbols

10 Stockpiling room (bedrock tank)
DESCRIPTION OF SYMBOLS 11 Stratum 12 Protective pipe 13 Seal mechanism 14 Shut-off valve 15 Motor 16 Pump 17 Pumped liquid pipe 18 Head plate 19 Weir (skirt)
20 Specified liquid 21 Bottom water 22 Plug 23 Water seal 24 Gas pipe 25 Pressure sensor 26 Specified liquid discharge pipe 27 Spec liquid return pipe 28 Pressure sensor 29 Emergency drain pump 30 Spec liquid discharge pipe 31 Spec liquid return valve 32 Purge gas supply pipe 33 Pressure sensor 34 Purge gas discharge pipe 35 Pressure sensor 36 Gas detector 37 Outer pipe

Claims (6)

And stockpiling chamber stockpiling disposed specifications liquid underground, the protective tube communicating with said reserve chamber, the liquid being pumped tube connected to the discharge port of the pump and the pump for pumping specifications liquid stockpiling chamber to the protective tube And a liquid storage device comprising a shutoff valve that shuts off the flow of the specification liquid in the storage chamber into the protective pipe, and when the shutoff valve is closed, the specification liquid in the protective pipe is exposed to the outside. There is provided drainage means for discharging, and the drainage means sends a specification liquid pressurizing means for sending an inert gas into the protective tube and pressurizing the specification liquid in the protective tube, and the specification liquid pressurizing means applies the specification liquid. A pressure sensor for measuring the gas pressure in the gas pipe for supplying the inert gas, and a pressure sensor for measuring the pressure in the storage chamber. A pressure sensor to measure and provide through the gas pipe Liquid stockpile apparatus characterized by controlling the pressure of the inert gas. 2. The liquid storage apparatus according to claim 1, wherein the specification liquid discharge means includes a specification liquid discharge pipe for discharging the specification liquid in the protective tube to the outside, and a specification liquid connected to the specification liquid discharge pipe and returned to the storage chamber. A liquid storage device comprising a return pipe . A storage room for storing specification liquid disposed in the basement, a protection pipe communicating with the storage room, a pump for pumping the specification liquid in the storage room into the protection pipe, and a pumping pipe connected to the discharge port of the pump And a liquid storage device comprising a shutoff valve that shuts off the flow of the specification liquid in the storage chamber into the protective pipe, and when the shutoff valve is closed, the specification liquid in the protective pipe is exposed to the outside. A draining means for discharging is provided, and the draining means is provided with a drainage pump different from the pump in the protective tube, and the drainage pump sends out the specification liquid in the protective tube to the outside of the protective tube. It is comprised in the liquid storage apparatus characterized by the above-mentioned. 2. The liquid storage device according to claim 1 , wherein the specification liquid discharge means includes a specification liquid return valve provided on a side wall of the protection pipe and configured to return the specification liquid in the protection pipe to the storage chamber. Liquid storage device. In the liquid stockpiling apparatus according to請Motomeko 1 to 4, from the stockpile chamber of the protective tube and a double tube structure including an inner tube and an outer tube top, the inner and outer tubes of the double tube structure An inert gas supply means for supplying an inert gas as a purge gas to a gap therebetween, an inert gas discharge means for discharging the inert gas from the gap, and a specification liquid contained in the inert gas discharged from the gap A liquid storage apparatus comprising: a specified liquid gas detecting means for detecting gas; and further, a gas detecting device is installed on the ground and used together with the specified liquid gas detecting means to monitor gas leakage . And stockpiling chamber stockpiling disposed specifications liquid underground, the protective tube communicating with said reserve chamber, the liquid being pumped tube connected to the discharge port of the pump and the pump for pumping specifications liquid stockpiling chamber to the protective tube And a shut-off valve that shuts off inflow of flammable liquid in the storage chamber into the protective tube, and is configured to adjust the specification liquid level in the storage chamber by raising and lowering the bottom water level. In the operation method of the apparatus, when the shut-off valve is closed, the specification liquid in the protective pipe is discharged to the outside, the bottom water is introduced into the protective pipe, and the bottom water level is set to the ground level position as much as possible. A method for operating a liquid storage device.

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