Vent system and vent method

Abstract

This vent system (1) serves to discharge gas in an underground space (S1) communicating with an aboveground space (S2) via lifting tubes (22, 23), the system comprising: an inert gas cylinder (12) that is provided in the aboveground space (S2) and generates inert gas; an inert gas sending tube (13) for sending the inert gas to the underground space (S1); and a gas concentration measurement sensor (14) that measures the concentration of gas in the underground space (S1).

Description

[Technical Field]

[0001] The present disclosure relates to vent systems and methods. [Background technology]

[0002] In recent years, with the aim of achieving decarbonization and carbon neutrality, methods for supplying hydrogen gas and the safety of supplying hydrogen gas have been studied in order to utilize hydrogen gas. For example, Non-Patent Document 1 describes the provision of a hydrogen pipeline for transporting hydrogen and the detection of leaked hydrogen with a detector. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Tetsuji Morita, "Initiatives for Hydrogen Pipeline Supply in the City Gas Industry," Institute of Electrical Installation Engineers, Journal of the Institute of Electrical Installation Engineers 36 (4), 242-245, 2016 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology, hydrogen may leak from a hydrogen pipeline 93 that supplies hydrogen from a supply-side hydrogen tank 91 to a consumption-side hydrogen tank 92 in an underground space S1, as shown in FIG. 4 . The underground space S1 is a space defined by a manhole 94 or the like installed underground A. Hydrogen may also leak from the hydrogen pipeline 93 in a piping 95 that connects the underground spaces S1 to each other. In such cases, the leaked hydrogen diffuses outside the underground space S1 by natural diffusion. Furthermore, there is a risk of an explosion within the underground space S1 due to the hydrogen leaked into the underground space S1. Therefore, when performing work such as repairing equipment within the underground space S1, workers must ensure their own safety by waiting for the hydrogen in the underground space S1 to diffuse outside the underground space S1 before starting the work. Therefore, workers must wait for the leaked gas, such as hydrogen, in the underground space S1, where a gas transport path such as the hydrogen pipeline 93 is installed, to diffuse outside by natural diffusion, which can make it difficult to start work promptly.

[0005] The present disclosure was made in consideration of the above circumstances, and aims to provide a vent system and a vent method for quickly discharging gas leaking from a gas transport line in an underground space. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the vent system of the present disclosure is a vent system that exhausts gas in an underground space that is connected to an above-ground space via a lifting pipe, and includes an inert gas cylinder that is placed in the above-ground space and generates an inert gas, an inert gas supply pipe for supplying the inert gas to the underground space, and a gas concentration measurement sensor that measures the concentration of the gas in the underground space.

[0007] In addition, in order to solve the above-mentioned problems, the venting method of the present disclosure is a venting method performed by a vent system that exhausts gas in an underground space that is connected to an aboveground space via a lifting pipe, and includes the steps of generating an inert gas in the aboveground space, sending the inert gas into the underground space, and measuring the concentration of the gas in the underground space. [Effects of the Invention]

[0008] According to the vent system and vent method disclosed herein, gas leaking from a gas transport line in an underground space can be quickly discharged. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a vent system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a sequence diagram showing an example of a process for constructing the vent system shown in FIG. [Figure 3] FIG. 3 is a sequence diagram showing an example of the operation of the vent system shown in FIG. 2. [Figure 4] FIG. 1 is a schematic diagram illustrating a conventional underground space in which a gas transport passage is provided. DETAILED DESCRIPTION OF THE INVENTION

[0010] The overall configuration of this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram of a vent system 1 according to this embodiment.

[0011] As shown in Figure 1, the vent system 1 according to this embodiment is a system for discharging gas within an underground space S1 that is in communication with an aboveground space S2 via a pull-up pipe 22 and a pull-up pipe 23. The underground space S1 is a space defined by an underground structure 21, such as a manhole, tunnel, or handhole, provided underground A. The pull-up pipes 22 and 23 are attached to the underground structure 21, and the underground space S1 is in communication with an aboveground space S2 via the pull-up pipes 22 and 23.

[0012] The vent system 1 includes a gas leak detector 11, an inert gas cylinder 12, an inert gas supply pipe 13, an exhaust pipe 14, and a gas concentration measurement sensor 15.

[0013] The gas leak detector 11 detects gas leakage from a gas transport pipeline 24 in the underground space S1. The gas transport pipeline 24 is a pipeline for transporting gas from a supply gas tank 25 disposed in the aboveground space S2 to a consumption gas tank 26. In this embodiment, the gas is hydrogen, and the gas transport pipeline 24 is a hydrogen pipeline, but is not limited to this.

[0014] A portion of the gas transport pipeline 24 is disposed in the underground space S1. Specifically, one end of the gas transport pipeline 24 is connected to the supply port of the supply-side gas tank 25, and is configured so that gas supplied from the supply-side gas tank 25 is received into the gas transport pipeline 24 from the one end. The other end of the gas transport pipeline 24 is connected to the receiving port of the consumption-side gas tank 26, and is configured so that gas supplied from the supply-side gas tank 25 and transported through the gas transport pipeline 24 flows into the consumption-side gas tank 26 via the receiving port. A portion of the gas transport pipeline 24 is disposed inside the underground space S1 and inside a pipeline 27 that connects the underground spaces S1 to each other.

[0015] As a first example, the gas leak detector 11 may include a gas concentration measurement sensor installed in the underground space S1. The gas concentration measurement sensor measures the gas concentration in the underground space S1. The gas leak detector 11 may further include a controller that determines whether the gas concentration is equal to or greater than a leak threshold. In such a configuration, the controller determines that gas is leaking when it determines that the gas concentration is equal to or greater than the leak threshold, and determines that gas is not leaking when it determines that the gas concentration is less than the leak threshold. The controller may also output information indicating whether it has been determined that gas is leaking to an arbitrary output interface. The controller may be configured with dedicated hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), or may be configured with a processor, or may be configured with both.

[0016] As a second example, the gas leak detector 11 may be configured with a controller that determines whether or not gas is leaking based on the internal pressure of the supply-side gas tank 25 and the internal pressure of the consumption-side gas tank 26. In such a configuration, the controller determines whether or not the difference between the internal pressure of the supply-side gas tank 25 and the internal pressure of the consumption-side gas tank 26 is equal to or greater than a difference threshold. If the controller determines that the difference is equal to or greater than the difference threshold, it determines that gas is leaking, and if the controller determines that the difference is less than the difference threshold, it determines that gas is not leaking. The controller may also output information indicating whether or not it has been determined that gas is leaking to an arbitrary output interface.

[0017] The inert gas cylinder 12 is disposed in the aboveground space S2 and generates an inert gas. The inert gas is a chemically stable gas that does not readily react with other elements or compounds. Examples of the inert gas include helium, neon, argon, krypton, xenon, radon, nitrogen gas, and carbon dioxide. The inert gas cylinder 12 may be disposed in the aboveground space S2. Alternatively, the inert gas cylinder 12 may be portable and moved to the aboveground space S2 above the underground space S1 where the gas leak was detected.

[0018] The inert gas supply pipe 13 is a pipe for supplying the inert gas to the underground space S1. One end of the inert gas supply pipe 13 (on the underground space S1 side) is arranged in the underground space S1, and the other end (on the aboveground space S2 side) is arranged in the aboveground space S2. The inert gas cylinder 12 is connected to the end of the inert gas supply pipe 13 on the aboveground space S2 side, so that the inert gas supply pipe 13 can receive the inert gas generated by the inert gas cylinder 12 from the end on the aboveground space S2 side and pressure-supply the inert gas.

[0019] The inert gas supply pipe 13 may be a flexible pipe disposed inside the pull-up pipe 22. The pull-up pipe 22 may be, for example, a pipe already installed on a utility pole already installed near an underground structure 21 such as a manhole. The flexible pipe is made of a material that can withstand the gas pumping force (e.g., 0.95 MPa), and this material may be, for example, stainless steel (SUS: Steel Use Stainless). The flexible pipe has a diameter that allows it to be inserted into the pull-up pipe 22. An example of the diameter of the pull-up pipe 22 used on a typical utility pole is 75 mm.

[0020] The discharge pipe 14 is a pipe for discharging gas in the underground space S1 to the aboveground space S2. The end of the discharge pipe 14 on the underground space S1 side is disposed in the underground space S1, and the end on the aboveground space S2 side is disposed in the aboveground space S2. The discharge pipe 14 receives, from the end on the underground space S1 side, gas that flows out from the underground space S1 as the inert gas is sent to the underground space S1. The gas received from the end on the underground space S1 side then passes through the discharge pipe 14 to reach the end on the aboveground space S2 side and is discharged to the aboveground space S2.

[0021] The discharge pipe 14 may be a flexible pipe disposed within the pull-up pipe 23. The pull-up pipe 23 may be a pipe already installed on a utility pole already installed near an underground structure 21 such as a manhole. The flexible pipe is made of a material that can withstand the pressure-feeding force of the gas, and this material may be stainless steel, for example. The flexible pipe has a diameter that allows it to be inserted into the pull-up pipe 23. An example of the diameter of the pull-up pipe 23 used on a typical utility pole is 75 mm.

[0022] The gas concentration measurement sensor 15 measures the concentration of gas in the underground space S1. In one example, the gas concentration measurement sensor 15 may measure the concentration of gas in the underground space S1 that is discharged to the aboveground space S2. In another example, the gas concentration measurement sensor 15 may be a gas concentration measurement sensor that constitutes the gas leak detector 11, and in such a configuration, the gas concentration measurement sensor 15 may measure the concentration of gas in the underground space S1.

[0023] <Construction of a vent system> Here, a process for constructing the vent system 1 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a sequence diagram showing an example of a process for constructing the vent system 1 according to this embodiment.

[0024] In step S11, gas is pumped from the gas tank 25 on the supply side to the gas tank 26 on the consumption side.

[0025] In step S12, the gas leak detector 11 detects whether or not gas is leaking from the gas transport pipeline 24 within the underground space S1. Here, as described above, the gas leak detector 11 may detect whether or not gas is leaking based on the gas concentration, or may detect whether or not gas is leaking based on the internal pressure of the supply-side gas tank 25 and the internal pressure of the consumption-side gas tank 26.

[0026] If a gas leak is detected in step S13, the vent system 1 is constructed. Specifically, the inert gas cylinder 12 is positioned so that the inert gas generated by the inert gas cylinder 12 is received at the end of the inert gas supply pipe 13 on the ground space S2 side. Here, a flexible pipe may be disposed in the lifting pipe 22. Also, a flexible pipe may be disposed in the lifting pipe 23.

[0027] In step S14, the vent system 1 is operated.

[0028] <Vent system operation> Here, the operation of the vent system 1 in step S14, which discharges gas in the underground space S1 that is in communication with the aboveground space S2 via the pull-up pipes 22 and 23, will be described with reference to Fig. 3. Fig. 3 is a sequence diagram showing an example of the operation of the vent system 1 according to this embodiment. The operation of the vent system 1 described with reference to Fig. 3 corresponds to a venting method performed by the vent system 1 according to this embodiment.

[0029] In step S141, the inert gas cylinder 12 generates the inert gas in the ground space S2.

[0030] In step S142, the inert gas supply pipe 13 supplies the inert gas generated in step S141 to the underground space S1.

[0031] In step S143, the gas concentration measuring sensor 15 measures the gas concentration.

[0032] If it is determined in step S143 that the concentration of the gas measured is equal to or greater than the predetermined value, the process returns to step S141 and the operation is repeated. If it is determined in step S143 that the concentration of the gas measured is less than the predetermined value, the vent system 1 ends its operation.

[0033] When it is determined that the gas concentration is less than the predetermined value and the vent system 1 has finished operating, workers can enter the underground space S1 and start repairing the equipment and the like installed in the underground space S1. The equipment that the workers will repair is, for example, the gas transport pipeline 24.

[0034] As described above, according to this embodiment, the vent system 1 is disposed in the aboveground space S2 and includes an inert gas cylinder 12 for pressurizing and feeding an inert gas, an inert gas supply pipe 13 for supplying the inert gas to the underground space S1, and a gas concentration measurement sensor 15 for measuring the concentration of the gas in the underground space S1. This allows the vent system 1 to exhaust gas leaked from the gas transport pipeline 24 from the underground space S1. Furthermore, the leaked gas can be prevented from reaching another underground space S1 through the pipeline 27, preventing the other underground space S1 from being filled with gas. That is, even if gas leaks from the gas transport pipeline 24, it does not accumulate in the underground space S1, preventing the gas concentration from increasing. Furthermore, since the gas concentration in the underground space S1 is measured, workers can reliably determine whether it is safe to enter the underground space S1. Furthermore, by knowing when the gas concentration has decreased to a safe level, workers can enter the underground space S1 early and perform their work in the underground space S1 without delay.

[0035] Furthermore, according to this embodiment, the gas concentration measurement sensor 15 measures the concentration of gas discharged from the underground space S1 to the aboveground space S2 through the discharge pipe 14. This allows workers to recognize the gas concentration in the aboveground space S2 without entering the underground space S1, which may be filled with gas. This allows workers to stay safer.

[0036] Furthermore, according to this embodiment, the inert gas supply pipe 13 may be a flexible pipe disposed inside the pull-up pipe 22. As described above, the pull-up pipe 22 may be a pipe already installed on a utility pole located near an underground structure 21 such as a manhole, and therefore may be damaged due to aging or other factors. For this reason, when the pull-up pipe 22 without a flexible pipe disposed therein supplies the inert gas, damage to the pull-up pipe 22 may cause the inert gas to leak outside the pull-up pipe 22. In contrast, by using the inert gas supply pipe 13 as a flexible pipe disposed inside the pull-up pipe 22, leakage of the inert gas during supply can be suppressed.

[0037] Furthermore, as described above, the pull-up pipe 22 may be a pipe installed on an electric pole already installed near the underground structure 21 such as a manhole, and therefore may not have been formed with consideration given to the effects of an increase in internal pressure due to the supply of inert gas. For this reason, when the pull-up pipe 22 without a flexible pipe disposed therein supplies the inert gas, the pull-up pipe 22 may be affected, for example, by being damaged by the inert gas. In contrast, by using the inert gas supply pipe 13 as a flexible pipe disposed inside the pull-up pipe 22, the effects of the supply of the inert gas on the pull-up pipe 22 can be suppressed.

[0038] Furthermore, the flexible pipe is made of a flexible material, so that the flexible pipe can be placed inside the pull-up pipe 22 even if the route of the pull-up pipe 22 to the underground space S1 is curved or sloped.

[0039] All publications, patent applications, and technologies mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, and technology was specifically and individually indicated to be incorporated by reference.

[0040] Although the above-described embodiments have been described as typical examples, it will be apparent to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications or alterations are possible without departing from the scope of the claims. [Explanation of symbols]

[0041] 1. Vent System 11 Gas leak detector 12 Inert gas cylinder 13 Inert gas supply pipe 14 Discharge piping 15 Gas concentration measurement sensor 21 Underground structures 22, 23 Lift pipe 24 Gas Transmission Pipeline 25 Supply gas tank 26 Gas tank on the consumer side 27 Conduit S1 underground space S2 Ground space A Underground

Claims

1. A vent system for discharging gas in an underground space that is in communication with an aboveground space via a lift pipe, an inert gas cylinder disposed in the aboveground space and generating an inert gas; an inert gas supply pipe disposed inside the lifting pipe for supplying the inert gas to the underground space; a gas concentration measurement sensor for measuring the concentration of the gas in the underground space; A vent system comprising:

2. The vent system of claim 1 , wherein the gas concentration measurement sensor measures the concentration of the gas in the underground space that is vented to the aboveground space.

3. 3. The vent system according to claim 1, wherein the inert gas supply pipe is a flexible pipe.

4. A venting method performed by a vent system that exhausts gas in an underground space that is in communication with an aboveground space via a lift pipe, comprising: generating an inert gas in the ground space; Sending the inert gas through the uptake pipe into the underground space; measuring the concentration of the gas in the underground space; A venting method comprising:

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