Gas leakage detection system

Abstract

To enable water if standing inside of a suction tube that draws in a detection gas to be removed and prevent the suction tube from being closed by standing water, thereby enabling gas leakage to be detected quickly and reliably.SOLUTION: Provided is a system comprising: a gas detector 13 of suction type which is provided to a gas charger 12; and a suction tube 15 for introducing a detection gas by being subordinated to a charging hose 14 of the gas charger 12 and sending it to the gas detector 13. A suction port 15a at the tip of the suction tube 15 is held in a nozzle 14a section at the tip of the charging hose 14 and gas leakage in a nozzle 14a connecting section is detected. An introduction port 15b is formed in at least a section of the tube wall of the suction tube 15 that passes the detection gas drawn in from the suction port 15a through to the inside of the suction tube 15 and enables the ambient air to be introduced. Water having entered the suction tube 15 and standing there is ejected by the ambient air from the introduction port 15b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for detecting gas leakage at a connection portion of a filling nozzle, which is provided in an equipment for filling a fuel gas such as hydrogen gas. [Background technology]

[0002] At hydrogen stations where hydrogen gas is filled up for fuel cell vehicles, gas detection devices are installed in various locations to quickly detect gas leaks. One of these devices detects leaks at the connection point between the filling nozzle at the end of the filling hose extending from the gas filling device (dispenser) and the filling port of the vehicle being filled.

[0003] For this leak detection, a suction-type gas detection device is used, which sucks in the test gas using a pump. That is, this type of gas detection device has a suction tube for sucking in the test gas, and the suction tube itself is held along the filling hose, with the suction port at the tip of the suction tube held in the filling nozzle. If the concentration of the target gas in the test gas sucked through the suction tube during filling or other such process is above a predetermined concentration, an alarm will be sounded.

[0004] Aspirating-type gas detection devices actively aspirate the test gas, but if water droplets adhere to the gas detection element, this can easily cause breakdowns or other malfunctions. For this reason, filters are provided to remove water droplets from the aspirated test gas (see Patent Document 1 below). Some devices have also been proposed that include a drain removal device to remove moisture from test gases that contain a large amount of water vapor (see Patent Document 2 below).

[0005] These measures are taken to ensure accurate detection. However, unlike hydrogen stations for fuel cell vehicles, when filling gas in outdoor locations where there is a high chance of contact with water, such as ports or construction sites, and when there is a difference in elevation between the gas filling device and the filling destination, there is a possibility that water may seep into and accumulate in the suction tube. If a large amount of accumulated water accumulates and accumulates, it may form a column inside the suction tube, creating a plug that cannot be sucked up by the suction pump of the gas detection device. In this case, even if a condition that should trigger an alarm is detected, it will not be detected. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-52306 [Patent Document 2] Special Publication No. 8-7118 Summary of the Invention [Problem to be solved by the invention]

[0007] To provide a gas leak detection device that can quickly and reliably detect gas leakage by removing water even if it accumulates in a suction tube and by preventing water from accumulating and clogging the suction tube. [Means for solving the problem]

[0008] To this end, the present invention employs the following configuration in a gas leak detection system comprising a suction-type gas detection device provided in a gas filling device, and a suction tube attached to the filling hose of the gas filling device to send the gas to be detected to the gas detection device, with the suction port of the suction tube held in the nozzle portion at the tip of the filling hose.

[0009] That is, an inlet is formed in at least a part of the tube wall of the suction tube, which allows the test gas sucked from the suction port to pass into the suction tube while allowing outside air to be drawn in. The inlet can be configured to open and close to draw in outside air only when necessary, or to be extended to always draw in the test gas from the outside air.

[0010] In this configuration, when the inlet is opened to introduce outside air, the accumulated water in the suction tube is broken up and sucked in, and then allowed to flow down and be discharged.When outside air is constantly introduced through the inlet, the flow of the test gas near the inlet is maintained, preventing the accumulation of an amount of water that cannot be sucked in. [Effects of the Invention]

[0011] According to this invention, a configuration is adopted in which outside air is introduced through the inlet to break up clumps of water accumulated in the suction tube and prevent water from collecting near the inlet, thereby preventing the inability to suction the test gas, thereby maintaining the desired detection performance and contributing to ensuring safety during fuel gas filling operations. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a gas leak detection system. [Figure 2] FIG. 2 is an explanatory diagram showing the function of the inlet of FIG. 1. [Figure 3] FIG. 1 is a schematic diagram of a gas leak detection system. [Figure 4] FIG. 1 is a schematic diagram of a gas leak detection system. [Figure 5] FIG. 5 is an explanatory diagram showing the function of the inlet of FIG. 4. [Figure 6] FIG. 1 is a schematic diagram of a gas leak detection system. [Figure 7] FIG. 1 is a schematic diagram of a gas leak detection system. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below with reference to the drawings.

[0014] The gas leak detection system 11 is suitably applied to equipment for filling hydrogen gas, an example of fuel gas, into fuel tanks mounted on ships, heavy machinery, construction machinery, submarines, etc. In other words, the system is configured to be able to perform the desired leak detection even when the location where the connection for filling is made is outdoors, without a roof, near water, and there is an elevation difference between the location where the gas filling device (dispenser) 12 is placed (for example, a wharf, etc.).

[0015] In this case, leak detection is performed to detect leaks of the target gas, i.e., hydrogen gas, at the connection portion for filling. For this reason, as shown in Figure 1, gas leak detection system 11 is equipped with a suction-type gas detection device 13 provided in gas filling device 12, and a suction tube 15 attached to filling hose 14 of gas filling device 12, which introduces the gas to be detected and sends it to gas detection device 13. Suction port 15a at the tip of suction tube 15 is held by nozzle 14a at the tip of filling hose 14.

[0016] The gas filling device 12 is installed in a location close to a filling destination having a fuel gas tank, such as a wharf or construction site. A compressor and a pressure accumulator (not shown) are connected, and the hydrogen gas in the pressure accumulator is cooled by a precooler to properly fill the gas at the specified pressure and temperature. Although not shown, the gas filling device 12 is also provided with a filling mechanism that measures the filling amount and an operation panel for operating the filling mechanism.

[0017] The filling hose 14 of the gas filling device 12 can be composed solely of a flexible hose for high-pressure gas, or it can be composed of a flexible hose and a steel pipe combined in the longitudinal direction. The filling hose 14 can be supported by a device such as a crane (not shown) to make it easier to move the nozzle 14a at the tip, and can be chosen as desired depending on the intended use. The schematic diagram in Figure 1 shows that the filling hose 14 is long, and the nozzle 14a at the tip is moved to a location at a different height than the installation surface of the gas filling device 12.

[0018] The suction-type gas detection device 13 provided in the gas filling device 12 has a pump 31 for sucking in the gas to be detected. On the negative pressure side of the pump 31, there are arranged, in order, a gas detection unit 32 consisting of a gas detection element and the like, a flow check filter 33 that measures the flow rate and performs filtration, an auto-drain 34 that removes any drainage that has entered, and a suction tube 15. The suction tube 15 is made of a flexible resin tube, preferably a transparent resin tube, because this allows visual confirmation of whether water has accumulated inside.

[0019] The suction tube 15 has an inlet 15b in at least a portion of the tube wall, which allows the test gas sucked through the suction port 15a at the tip to pass into the suction tube 15 while allowing outside air to be introduced. The position where the inlet 15b is formed is a position where water is expected to enter the suction tube 15 and accumulate in a columnar shape of a length that cannot be sucked up by the suction force of the pump 31. This position is set depending on the capacity of the pump 31 as well as the support mode of the filling hose 14 that extends together with the suction tube 15. The inlet 15b is not limited to one location as in the illustrated example, but may be provided in multiple locations.

[0020] There are two types of configurations for the inlet 15b. One is a type that opens when necessary, and the other is a type that opens all the time. Specific examples of the configurations are described below.

[0021] <Aspect 1> The inlet 15b shown in FIG. 1 is normally closed and is configured to open when necessary. That is, the inlet 15b is provided with an opening / closing device 51 that opens and closes the inlet 15b when necessary. The inlet 15b and the opening / closing device 51 can be formed by, for example, installing an existing residual pressure exhaust valve with a pipe joint, a switching valve, or a three-way joint with a cock midway along the length of the suction tube 15. That is, a tube is connected to two joints of the residual pressure exhaust valve with a pipe joint, the switching valve, or the three-way joint with a cock, and the remaining opening is left as the inlet 15b. Switching between a state in which the two joints in the opening / closing device 51 are connected to close the inlet 15b and a state in which the inlet 15b is open is performed by pressing a push button or rotating a lever provided on the exterior of the opening / closing device 51. The opening and closing operation is manual.

[0022] Inlet 15b and opening / closing device 51 can be formed by a separate joint member such as a residual pressure exhaust valve with a pipe joint, or they can also be formed by providing an air valve with a check valve (not shown) on the circumferential surface of suction tube 15. An air valve with a check valve is used to form the air intake and exhaust port of an air-filled member such as a life jacket, and is configured so that the internal check valve, which is normally closed, opens when the bulge at the base is compressed and deformed. The opening of the air valve with a check valve is inlet 15b, and the check valve and the part surrounding it are opening / closing device 51.

[0023] In a configuration with an openable inlet 15b, the inlet 15b is normally closed, allowing the test gas to flow through the suction tube 15. If water enters through the suction port 15a of the suction tube 15, a column of water W can be expected to form inside the suction tube 15, as shown in Figure 2(a). In this case, opening one of the inlets 15b in the water-filled area, as shown in Figure 2(b), allows outside air to enter through the inlet 15b. A small amount of this outside air is sufficient, as it does not adversely affect gas detection performance. The introduced outside air breaks up the column of water W, and the separated water Wa and Wb on the pump 31 side are pulled by the suction force of the pump 31 and discharged into the auto-drain 34. The water on the suction port 15a side flows down, opening the lumen of the suction tube 15, or is discharged through the suction port 15a. In addition, in (a) of Figure 2, the white arrow shown with a dashed line indicates a state in which the suction force of pump 31 is acting but water cannot be sucked in, and in (b) the white arrow shown with a solid line indicates a state in which the suction force of pump 31 is acting and water can be sucked in.

[0024] In addition to the inlet 15b, a drain port 15c can also be formed in the suction tube 15, as in the gas leak detection system 11 shown in Fig. 3. The drain port 15c is normally closed and is formed in a position different from the inlet port 15b.

[0025] The drain outlet 15c can be formed by inserting an opening / closing device 51 consisting of a residual pressure exhaust valve with a pipe joint, a switching valve, or a three-way joint with a cock, similar to the inlet 15b, but it may also have a simple configuration in which the drain outlet 15c is normally closed by simply attaching and detaching a plug.

[0026] In the illustrated example, the drain outlet 15c is located upstream of the inlet 15b, but it may be located downstream or in both locations. As with the inlet 15b, the location is determined depending on the support mode of the filling hose 14, etc. If the support mode of the filling hose 14 requires that the drain outlet 15c be located in a position from which water always flows down, the drain outlet 15c can also be used as a drain basin that can store an appropriate amount of wastewater. The drain basin can be made of a tube or the like, and its bottom is sealed with a removable cap or the like.

[0027] <Aspect 2> Inlet 15b shown in Fig. 4 is always open and is configured to minimize accumulation of water in the suction tube. That is, as shown in Fig. 5, auxiliary tube 16 is provided at inlet 15b, and suction port 16a at the tip of auxiliary tube 16 is held in nozzle 14a at the tip of filling hose 14 as shown in Fig. 4.

[0028] The formation of such inlet port 15b and the connection to the auxiliary tube 16 can be achieved by inserting a three-way joint 52 into the suction tube 15. The three-way joint 52 may be T-shaped as shown in FIG. 4 or Y-shaped (not shown). One of the ports of the three-way joint serves as the inlet port 15b.

[0029] In the configuration of inlet 15b having auxiliary tube 16, as shown by the solid white arrow in Figure 5, the suction of pump 31 causes the test gas to flow through suction tube 15 and also through auxiliary tube 16. Therefore, the airflow prevents water from accumulating near inlet 15b. Even though the outside air is outside air, it is the test gas at nozzle 14a, and therefore will not cause false detection by gas detection device 13.

[0030] In the gas leak detection system 11 of this embodiment, the drain port 15c as shown in FIG.

[0031] <Aspect 3> The gas leak detection system 11 shown in Fig. 6 is provided with an opening / closing device 51 at the inlet 15b, and an auxiliary tube 16 is provided at the inlet 15b, with the suction port 16a at the tip of the auxiliary tube 16 held at the nozzle 14a at the tip of the filling hose 14. In other words, this is a combined embodiment of the gas leak detection systems 11 shown in Figs. 1 and 4.

[0032] The portion having the inlet 15b can be constructed by installing an opening / closing device 51 consisting of an existing switching valve or a three-way joint with a cock in the middle of the suction tube 15. One port of the three-way joint becomes the inlet 15b, and the auxiliary tube 16 is connected to this inlet 15b.

[0033] In this configuration, in a normal state, the inlet 15b is closed by the opening / closing device 51, and the test gas is sucked through the suction tube 15. When water accumulates in the inlet 15b and the test gas can no longer be sucked, the opening / closing device 51 is opened to suck the test gas through the auxiliary tube 16. Then, the test gas enters through the inlet 15b, breaking up the water mass and clearing the blockage inside the suction tube 15.

[0034] Furthermore, if the blockage due to infiltrated water occurs upstream of the inlet 15b and there is no other inlet at the blocked part, the opening / closing device 51 is opened to switch to suction of the test gas from the auxiliary tube 16.

[0035] In this way, the auxiliary tube 16 extending from the inlet 15b equipped with the opening and closing device 51 not only eliminates clogging of the water, but is also used as a backup suction path in case of an unexpected situation.

[0036] In this gas leak detection system 11 as well, the drain port 15c as shown in FIG.

[0037] In addition, in the gas leak detection system 11 equipped with an inlet 15b having an opening / closing device 51, including the example shown in Figure 4, the inlet 15b may be configured to be opened and closed automatically, as shown in Figure 7.

[0038] That is, gas detection device 13 is configured to have a flow rate decrease detection function, and opening / closing device 51 is configured to be a three-port solenoid valve. Control unit 35 of gas detection device 13 is configured to perform a control operation to open opening / closing device 51, which is the three-port solenoid valve, when it detects that the flow rate has decreased to a predetermined flow rate or less.

[0039] In this configuration, since inlet 15b automatically opens when a drop in flow rate occurs, if the drop in flow rate is due to accumulated water, the detection function is restored. If the drop in flow rate is due to another cause, opening inlet 15b will not resolve the issue, so you will need to check for clogged filters, clogged other parts of suction tube 15, or a malfunction of pump 31.

[0040] Since the opening operation of the inlet 15b is performed automatically, unlike manual opening operation, it is possible to deal with the clogged area even if it is in a place that is out of the reach of the worker.

[0041] As described above, it is possible to release blockages caused by water or prevent blockages from occurring by forming inlet 15b in suction tube 15. Therefore, even at filling sites where blockages caused by water are expected, it is possible to maintain the reliability of gas leak detection, prevent detection delays, and ensure safety.

[0042] The above-described configuration is one embodiment for carrying out the present invention, but the present invention is not limited to this, and other configurations can also be adopted.

[0043] For example, the suction tube 15 may have a layer of water-coloring ink on the inner surface of the tube wall so that it is clearly visible when water has accumulated.

[0044] The outside air introduced into the inlet may be the ambient air surrounding the filling hose 14, or a gas that does not affect the artificially provided detection, such as nitrogen. The outside air introduced may be allowed to flow in naturally, or may be compressed.

[0045] The fuel gas may be other than hydrogen gas. [Explanation of symbols]

[0046] 11...Gas leak detection system 12...Gas filling device 13...Gas detection device 14...Filling hose 14a...Nozzle 15...Suction tube 15a...Suction port 15b...Entrance 15c…Drain port 16...Auxiliary tube 16a...Suction port 34...Auto drain 51...Switchgear

Claims

1. A gas leak detection system comprising a suction type gas detection device provided in a gas filling device, and a suction tube attached to a filling hose of the gas filling device to introduce a gas to be detected and send it to the gas detection device, wherein a suction port at the tip of the suction tube is held in a nozzle portion at the tip of the filling hose, An inlet is formed in at least a part of the tube wall of the suction tube, which allows the test gas sucked from the suction port to pass into the suction tube while allowing outside air to be introduced. Gas leak detection system.

2. An auto-drain is provided downstream of the suction tube in the gas detection device. The gas leak detection system according to claim 1 .

3. An opening and closing device is provided at the inlet The gas leak detection system according to claim 1 or 2.

4. An auxiliary tube is provided at the inlet, and the tip of the auxiliary tube is held in the nozzle portion at the tip of the filling hose.

3. The gas leak detection system according to claim 1 or 2.

5. A normally closed drain port is formed at a position different from the inlet port in the suction tube. The gas leak detection system according to claim 1 or 2.

6. The gas detection device has a flow rate reduction detection function, The opening and closing device is composed of a three-port solenoid valve, When a flow rate drop below a predetermined value is detected in the control unit of the gas detection device, a control operation is performed to open the three-port solenoid valve. The gas leak detection system according to claim 3 .

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