Gas leak detection device and gas meter

Abstract

A gas leak detection device (10) is disposed in a gas pipeline (20) that supplies gas to a gas appliance (21) and is equipped with an on / off valve (24). The gas leak detection device includes: a pressure gauge (13) for measuring the pressure of gas in the gas pipeline downstream of the on / off valve; an output device for outputting information; and a control device (11). The control device performs a guidance output action to output guidance information for closing the on / off valve to the output device. After the guidance output action is performed, a pressure measurement action is performed to measure the pressure by the pressure gauge. A gas leak determination action is performed to determine the possibility of gas leak based on the pressure measured by the pressure measurement action.

Description

Technical Field

[0001] This disclosure relates to a gas leak detection device and gas meter for determining the possibility of gas leakage in gas piping. Prior Technology

[0002] As a conventional gas leak detection device, there is a known gas leak detection device, such as the one described in Patent Document 1. This gas leak detection device closes the shut-off valve when the possibility of gas use is low, and determines that there is a gas leak when the gas pressure has dropped to a certain level. Previous technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 8-5502 Summary of the Invention

[0004] The problem the invention aims to solve Traditional gas leak detection devices define periods of the day when the likelihood of gas equipment use is low as low-probability gas use and automatically shut off the shut-off valves. However, these periods of low-probability gas use are not always times when users do not use gas. Furthermore, besides periods of low-probability gas use, there may be situations where users wish to detect gas leaks. Therefore, traditional gas leak detection devices have the problem of not being able to detect gas leaks according to the user's intentions.

[0005] This disclosure is an invention made to solve such problems, with the aim of providing a gas leak detection device and gas meter that can detect the possibility of gas leaks according to the user's intention. The means to solve the problem

[0006] The disclosed gas leak detection device is configured in a gas pipeline that supplies gas to gas appliances and is equipped with an on / off valve. The gas leak detection device includes: a pressure gauge for measuring the pressure of gas in the gas pipeline downstream of the on / off valve; an output device for outputting information; and a control device that performs a guide output action to output guide information to close the on / off valve to the output device. After the guide output action is performed, a pressure measurement action is performed to measure the pressure using the pressure gauge. A gas leak determination action is performed to determine the possibility of gas leak based on the pressure measured by the pressure measurement action. Invention Effects

[0007] In a gas leak detection device like this, the user can perform the valve closing operation based on the guidance information output to the output device caused by the guidance output action. With the gas pipeline shut off by the user using the valve, the pressure of the gas in the pipeline is measured, and the likelihood of a gas leak is determined based on the measured pressure. In this way, the possibility of a gas leak can be detected according to the user's intention.

[0008] The above-disclosed objects, other objects, features, and advantages will become clear from the following detailed description of preferred embodiments, with reference to the accompanying drawings. Simple Explanation of the Diagram

[0009] Figure 1 is a functional block diagram that schematically shows the composition of the gas leak detection device and gas meter of embodiments 1 to 3 and variations 1 to 4 of this disclosure. Figure 2 is a flowchart showing an example of gas detection treatment in Embodiment 1 of this disclosure. Figure 3A shows a display device that has already displayed guidance information. Figure 3B shows a display device that has already displayed information about the pressure gauge reading. Figure 3C shows a display device that has shown results indicating no possibility of gas leakage. Figure 3D shows a display device that has shown results indicating the possibility of gas leakage. Figure 4 is a flowchart showing an example of gas detection treatment in Embodiment 2 of this disclosure. Figure 5 is a flowchart showing an example of gas detection and treatment in Embodiment 3 of this disclosure. Figure 6 is a flowchart showing an example of gas detection processing of Modification 1 of this disclosure. Figure 7A shows a display device that shows results when there are significant changes in atmospheric pressure. Figure 7B shows a display device that shows results when there are significant changes in temperature. Figure 8 is a flowchart showing an example of gas detection processing in Modification 2 of this disclosure. Figure 9 is a flowchart showing an example of gas detection processing in Modification 3 of this disclosure. Figure 10 is a flowchart showing an example of gas detection processing in Modification 4 of this disclosure. Figure 11 is a functional block diagram that schematically shows the configuration of the gas leak detection device and gas meter of the variations 5 to 8 disclosed herein. Figure 12 is a flowchart showing an example of gas detection processing in Modification 5 of this disclosure. Figure 13 is a flowchart showing an example of gas detection processing in Modification 6 of this disclosure. Figure 14 is a flowchart showing an example of gas detection processing in Modification 7 of this disclosure. Figure 15 is a flowchart showing an example of gas detection processing in Modification 8 of this disclosure. Figure 16 is a flowchart showing an example of gas detection processing in Modification 9 of this disclosure. Implementation

[0010] Forms used to implement inventions The embodiments disclosed herein will now be described in detail with reference to the drawings. Furthermore, in all the drawings below, the same or equivalent elements will be given the same reference numerals, and repeated descriptions will be omitted.

[0011] <Implementation Form 1> As shown in Figure 1, the gas leak detection device 10 of Embodiment 1 disclosed herein is a device for detecting the possibility of gas leaks in the gas piping 20 and gas appliances 21, for example, it is installed in the gas meter 22 installed in the gas piping 20. The gas piping 20 is a pipeline connecting the gas supply source 23 and the gas appliance 21 that consumes gas, and supplies gas from the gas supply source 23 to the gas appliance 21. The gas appliance 21 is a device that consumes gas, such as a gas stove, water heater, and heater.

[0012] A main valve 24, or "gate switch," is installed on the gas piping 20. The main valve 24 is a user-operated manual valve that opens and closes the gas piping 20. Specifically, when the user opens the gas piping 20 using the main valve 24, gas flow is permitted. When the user closes the gas piping 20 using the main valve 24, gas flow is blocked.

[0013] A gas meter 22 is installed on the gas piping 20 between the on / off valve 24 and the gas appliance 21, and includes a flow meter 25 and a gas leak detection device 10. The gas leak detection device 10 includes a control device 11. Furthermore, the control device 11 of the gas leak detection device 10 also serves as the control device 11 of the gas meter 22. However, the control device of the gas leak detection device 10 and the control device of the gas meter 22 can also be installed separately. In this case, these control devices can also cooperate with each other to control the gas meter 22. Furthermore, the control device 11 will be described later.

[0014] The flow meter 25 is installed on the gas pipe 20 to measure the volume or mass of gas passing through the gas pipe 20 per unit time (instantaneous flow rate) and output it to the control device 11.

[0015] In addition, the gas leak detection device 10 includes a shut-off valve 12. The shut-off valve 12 is located upstream of the flow meter 25 on the gas piping 20. The shut-off valve 12 is controlled by the control device 11 to open and close the gas piping 20. That is, when the shut-off valve 12 is opened by the control device 11, the gas piping 20 is open, allowing gas to flow. When the shut-off valve 12 is closed by the control device 11, the gas piping 20 is shut off, preventing gas flow.

[0016] Furthermore, the gas leak detection device 10 includes a pressure gauge 13. The pressure gauge 13 is installed downstream of the gas pipe 20, below the shut-off valve 12, and measures the pressure of the gas in this gas pipe 20, outputting the pressure to the control device 11. The gas pressure measured by the pressure gauge 13 can also be the relative pressure of the gas relative to atmospheric pressure. Relative pressure is the difference between the absolute pressure of the gas and atmospheric pressure. Furthermore, the gas pressure measured by the pressure gauge 13 can also be the absolute pressure of the gas. This absolute pressure can also be calculated based on the atmospheric pressure measured by the barometer and the gas pressure measured by the pressure gauge 13.

[0017] In addition, the gas leak detection device 10 includes a display device 14 and a communication interface 15. The display device 14 is, for example, an LCD screen, and displays information. The communication interface 15 transmits and receives information with an external machine via wireless or wired communication. For example, the external machine is a computer of a gas company or the management company of the gas meter 22.

[0018] Furthermore, the gas leak detection device 10 includes an input device 16. The input device 16, for example, is a push-button switch, operated by the user to input information to the control device 11. For example, when the input device 16 is a push-button switch, the user operation of the push-button switch and the input information are pre-established to correspond. A short press operation of the push-button switch by the user for less than a predetermined time corresponds to a recovery instruction, which is the opening and closing of the gas piping 20 from the shut-off valve 12. Furthermore, the input device 16 may also include a communication interface 15. In this case, the communication interface 15 receives information from an external machine and inputs it to the control device 11.

[0019] The control device 11 is a computer, such as a microcontroller, that controls the electrical machinery of the gas meter 22. The control device 11 may include a processor and memory capable of accessing the processor. The processor controls various parts of the gas meter 22 by executing programs stored in the memory. Thus, the control device 11 performs various processes on the gas meter 22, such as flow measurement, safety procedures, and gas leak detection.

[0020] Furthermore, representative configurations of the control device 11 include, for example, the following: general-purpose processors, special-purpose processors, integrated circuits, FPGAs (Field Programmable Gate Arrays), ASICs (Application Specific Integrated Circuits), GPUs, and other computing devices, either individually or in combination of two or more, and operating according to a program stored in a memory device to achieve their control functions.

[0021] As a processor in such a computing device, it is a hardware circuit (or processing circuit) because it contains circuits composed of multiple transistors, memory, etc. Integrated circuits or ASICs also contain processors or processing blocks such as CPUs, and are therefore also hardware circuits. FPGAs contain multiple integrated logic circuits (functional blocks), and are therefore hardware circuits. GPUs contain multiple parallel-mounted computing circuits (cores), and are therefore hardware circuits. Software such as programs stored in memory devices is used in the hardware, i.e., the circuits (processors, integrated circuits, FPGAs, ASICs, GPUs, etc.). Alternatively, a computing device can also be configured as a logic circuit formed by known switching elements, subtractors, comparators, etc.

[0022] The specific configuration of the memory device is not particularly limited. For example, it can be configured as the internal memory of a microcomputer or microcontroller unit (MCU), or it can be configured as a separate memory. Furthermore, the memory device does not need to be a single device; there can be multiple devices.

[0023] <Flow Meter Measurement Processing> The control device 11 measures the flow rate of gas flowing in the gas pipeline 20 using a flow meter 25 at predetermined time intervals, such as 2-second intervals. Furthermore, the control device 11 accumulates the gas flow rate measured by the flow meter 25 and outputs this accumulated value as the consumption to a display device 14 or a communication interface 15. In this way, the gas consumption is displayed on the display device 14 or sent to external equipment such as gas companies via the communication interface 15.

[0024] <Safety Handling> The shut-off valve 12 is normally in the open state, and the gas pipeline 20 is open so that gas can flow. In this state, for example, the control device 11 measures the gas pressure in the gas pipeline 20 using the pressure gauge 13 at predetermined time intervals, such as 10-second intervals. Furthermore, when a predetermined safety condition occurs, the control device 11 performs valve-closing control on the shut-off valve 12, thereby shutting off the gas pipeline 20. This prevents gas from being supplied to the gas appliance 21, rendering the gas appliance 21 unusable. Such safety conditions include, for example, when the gas flow rate exceeds a predetermined flow rate and when the gas pressure drops below a predetermined pressure.

[0025] Furthermore, when the user briefly presses the input device 16 (push-button switch), the control device 11 determines that a recovery instruction corresponding to the short press operation has been input and executes the opening control of the shut-off valve 12, thereby opening the gas pipeline 20. This allows gas to be supplied to the gas appliance 21, making the gas appliance 21 usable. Such control settings, including the closing and opening control of the shut-off valve 12, are stored in memory.

[0026] <Gas Leak Detection and Handling> The gas leak detection process is performed by the control device 11 according to the flowchart in Figure 2. First, the control device 11 performs a start determination operation, which determines whether a start instruction for the gas leak detection process has been input by the input device 16 (step S10). This start instruction is pre-established in correspondence with user operations on the input device 16. For example, a user's long-press operation on the input device 16, i.e., the button switch, for a predetermined time or longer, is pre-established in correspondence with the start instruction for the gas leak detection process. In this case, the control device 11 monitors the long-press operation during periods when no long-press operation is performed on the button switch (step S10: No). On the other hand, when a long-press operation occurs, the control device 11 determines that a start instruction has been input by the input device 16 (step S10: Yes).

[0027] Next, the control device 11 determines whether the shut-off valve 12 is in the open state (step S11). This shut-off valve 12 is controlled to close or open by the control device 11 during safety procedures, and this control information is stored in memory. Therefore, when the latest control information is valve-closing control, the control device 11 determines that the shut-off valve 12 is in the closed state (step S11: No), and since gas leak detection cannot be performed, the process ends. On the other hand, when the control information for the shut-off valve 12 does not include valve-closing control, and the latest control information is valve-opening control, the control device 11 determines that the shut-off valve 12 is in the open state (step S11: Yes).

[0028] Next, the control device 11 performs a guidance display operation (step S12) to display guidance information for closing the on / off valve 24 on the display device 14. For example, as shown in FIG3A, the control device 11 displays guidance information "Please close the on / off valve" on the display device 14. The user sees the guidance information and performs the valve-closing operation of the on / off valve 24. In this way, the gas pipeline 20 is blocked by the on / off valve 24, and gas will not be supplied to the gas pipeline 20 and gas appliance 21 downstream of the on / off valve 24. Furthermore, since the gas appliance 21 is not in use, there is no gas flow in the gas pipeline 20 between the on / off valve 24 and the gas appliance 21.

[0029] Furthermore, control device 11 performs the first timing action (step S13). In this first timing action, control device 11 measures the remaining time starting from a first predetermined time, for example, 5 seconds, and displays the remaining time on display device 14 as shown in the example of FIG3A. This remaining time starts from the time point when the guidance information is displayed and gradually decreases as time passes. The user, by viewing the remaining time, is prompted to perform the valve closing operation of the open / close valve 24 within the remaining time.

[0030] Next, the control device 11 determines whether a first predetermined time has elapsed since the execution of the guidance display action (step S14). Here, before the first predetermined time has elapsed (step S14: No), the control device 11 measures the remaining time and displays it on the display device 14. Then, when the first predetermined time has elapsed and the remaining time becomes 0 (step S14: Yes), the control device 11 executes the second timing action (step S15). In the second timing action, the control device 11 measures the elapsed time since the end of the first timing action.

[0031] Next, the control device 11 performs a pressure measurement operation (step S16) by measuring the pressure using the pressure gauge 13. During the pressure measurement operation, the control device 11 measures the pressure of the gas in the gas pipeline 20 (downstream of the on / off valve 24) using the pressure gauge 13, and stores the pressure in its memory, even when the gas pipeline 20 and gas appliance 21 are not supplied with gas. Here, as shown in FIG3B, the control device 11 displays the pressure measurement on the display device 14.

[0032] Next, the control device 11 performs a gas leak determination action (step S17) based on the pressure measured by the pressure gauge operation to determine the possibility of a gas leak. In this gas leak determination action, the control device 11 calculates the difference between a predetermined reference pressure and the gas pressure measured by the pressure gauge operation, and determines whether this pressure difference is less than the predetermined pressure difference. This reference pressure is, for example, the gas pressure immediately after the valve 24 is closed, which is the gas pressure initially measured in the pressure gauge operation in step S16.

[0033] Furthermore, the possibility of gas leakage is determined based on the pressure drop (pressure difference) of the gas when the gas piping 20 is shut off by the on / off valve 24. Therefore, the reference pressure only needs to be a pressure that can produce such a pressure drop. For example, the reference pressure can also be the gas pressure before the on / off valve 24 is shut off. In this case, the control device 11 can also use the gas pressure measured by the pressure gauge 13 as the reference pressure after determining that the shut-off valve 12 is in the open state in step S11 and before executing the guidance display action in step S12.

[0034] In step S17, the control device 11 determines that the pressure difference from the reference pressure to the measured pressure is large when the pressure difference is above a predetermined pressure difference (step S17: No). Therefore, the control device 11 determines that there is a possibility of gas leakage in the gas piping 20 and gas appliances 21 downstream of the on / off valve 24.

[0035] Furthermore, as shown in Figure 3D, the control device 11 performs a result display operation, which displays the possibility of a gas leak based on the gas pressure measured by the pressure gauge operation. In this result display operation, the control device 11 displays the determination result of the possibility of a gas leak and the measured pressure measured by the pressure gauge operation in step S16 on the display device 14 (step S20). By viewing this display, the user can take measures such as contacting the gas company to deal with the gas leak, or operate the valve 24 to open it.

[0036] In contrast, if the control device 11 determines in step S17 that the pressure difference is less than a predetermined pressure difference (step S17: Yes), it determines whether the measurement time in the second measurement operation of step S15 has reached a predetermined time, such as 3 minutes (step S18). If the measurement time has not reached the predetermined time (step S18: No), the control device 11 returns to the process in step S16 and repeats the subsequent process. Thus, the control device 11 measures the gas pressure at predetermined time intervals.

[0037] Then, when the pressure difference is less than a predetermined pressure difference (step S17: yes), and the measurement time reaches a predetermined time (step S18: yes), the pressure difference from the reference pressure to the measured pressure is small. Therefore, the control device 11 determines that there is no possibility of gas leakage in the gas piping 20 and gas appliances 21 downstream of the on / off valve 24.

[0038] Then, as shown in Figure 3C, the control device 11 performs a result display operation. In this result display operation, the control device 11 displays the determination that there is no possibility of gas leakage, and the measured pressure from the pressure gauge operation in step S16, on the display device 14 (step S19). By viewing this display, the user can confirm that there is no possibility of gas leakage and perform the opening operation of the on / off valve 24. Consequently, since the gas pipeline 20 will be open, gas will be supplied to the gas appliance 21 through the gas pipeline 20, and therefore the gas appliance 21 can be used.

[0039] According to this gas leak detection process, the control device 11 performs a guidance display operation, displaying guidance information for closing the on / off valve 24 on the display device 14. The user views this guidance display and operates the on / off valve 24 to shut off the gas pipeline 20. In this way, gas leaks in the gas pipeline 20, etc., which have been shut off by the on / off valve 24, can be detected according to the user's intention.

[0040] Furthermore, the control device 11 performs a start determination action to determine whether a start instruction has been input by the input device 16. When the start determination action determines that a start instruction has been input, a guide output action is performed. In this way, the user can operate the input device 16 to input a start instruction, and the guide output action is performed in response to this start instruction. In this way, the on / off valve 24 can be closed according to the user's intention, and gas leaks in gas pipes 20, etc., which have been blocked by the on / off valve 24, can be detected.

[0041] <Implementation Mode 2> In the gas leak detection device 10 of Embodiment 2 disclosed herein, the control device 11 performs the gas leak detection process according to the flowchart shown in FIG4. In this FIG4 flowchart, instead of steps S12 to S14 in the FIG2 flowchart, step S30 is performed to close the shut-off valve 12. Furthermore, in the FIG4 flowchart, step S31 is performed to open the shut-off valve 12 after steps S19 to S20 in the FIG2 flowchart.

[0042] Specifically, the control device 11 performs a start determination action, which determines whether a start instruction for gas leak detection processing has been input by the input device 16 (step S10). If a start instruction has been input by the input device 16 (step S10: Yes), the control device 11 determines whether the shut-off valve 12 is in the open state (step S11). Here, if the shut-off valve 12 is in the closed state (step S11: No), the control device 11 terminates the gas leak detection processing.

[0043] On the other hand, when the shut-off valve 12 is in the open state (step S11: Yes), the control device 11 performs a shut-off operation to shut off the gas pipeline 20 via the shut-off valve 12 (step S30). In this shut-off operation, the control device 11 closes the shut-off valve 12 to shut off the gas pipeline 20. Therefore, gas will not be supplied to the gas pipeline 20 and gas appliances 21 downstream of the shut-off valve 12, and there will be no gas flow in the gas pipeline 20 between the shut-off valve 12 and the gas appliances 21.

[0044] Next, the control device 11 performs a pressure measurement operation using pressure gauge 13 (step S16). During the pressure measurement operation, the control device 11 measures the gas pressure in the gas pipeline 20 using pressure gauge 13, even when gas is not supplied to the gas pipeline 20 and gas appliances 21 downstream of the shut-off valve 12. Furthermore, the control device 11 performs a gas leak detection operation (step S17). In this gas leak detection operation, the control device 11 calculates the difference between the reference pressure and the measured pressure and determines whether this pressure difference is less than a predetermined pressure difference.

[0045] This reference pressure is, for example, the gas pressure immediately after the shut-off valve 12 is closed, which is the gas pressure initially measured during the pressure gauge operation in step S16. Furthermore, the possibility of gas leakage is determined based on the gas pressure decrease (pressure difference) caused by the shut-off valve 12 shutting off the gas piping 20. Therefore, the reference pressure only needs to be a pressure that can derive such a pressure decrease. For example, the reference pressure could also be the gas pressure before the shut-off valve 12 is closed. In this case, the control device 11 can also use the gas pressure measured by the pressure gauge 13 as the reference pressure after determining in step S11 that the shut-off valve 12 is in the open state, and before the shut-off valve 12 is closed in step S30.

[0046] In the gas leak detection operation of step S17, if the control device 11 determines that the pressure difference is above a predetermined pressure difference (step S17: No), then it determines that there is a possibility of gas leakage in the gas pipeline 20 and gas appliance 21 downstream of the shut-off valve 12. Then, as shown in FIG3D, the control device 11 displays the determination result of the possibility of gas leakage and the measured pressure measured by the pressure gauge operation in step S16 on the display device 14. Furthermore, the control device 11 opens the gas pipeline 20 by executing the valve opening control of the shut-off valve 12 (step S31), making the gas appliance 21 usable.

[0047] In contrast, when the pressure difference is less than a predetermined pressure difference (step S17: Yes) and the measurement time reaches a predetermined time (step S18: Yes), the control device 11 determines that there is no possibility of gas leakage in the gas pipeline 20 and gas appliance 21 downstream of the shut-off valve 12. Then, as shown in FIG3C, the control device 11 performs a result display operation, displaying the determination result that there is no possibility of gas leakage and the measured pressure measured by the pressure measurement operation in step S16 on the display device 14 (step S19). Furthermore, the control device 11 opens the gas pipeline 20 by executing the valve opening control of the shut-off valve 12 (step S31), making the gas appliance 21 usable.

[0048] According to this gas leak detection process, the control device 11 performs a start determination action to determine whether a start instruction has been input by the input device 16. When the start determination action determines that a start instruction has been input, the shut-off valve 12 is closed. In this way, by having the user input a start instruction through the input device 16, the shut-off valve 12 shuts off the gas pipeline 20 according to the user's intention. Accordingly, gas leaks in the gas pipeline 20, etc., which have been shut off by the shut-off valve 12, can be detected according to the user's intention.

[0049] <Implementation Mode 3> In the gas meter 22 of embodiment 3 disclosed herein, the control device 11 performs the gas leak detection process according to the flowchart shown in FIG5. In the flowchart of FIG5, the flow metering operation of step S40 is performed after the processing of step S15 in the flowchart of FIG2, and the acquisition operation of step S41 is performed after the processing of step S18 in the flowchart of FIG2. Furthermore, in the flowchart of FIG4, the flow metering operation of step S40 can also be performed after the processing of step S15, and the acquisition operation of step S41 can be performed after the processing of step S18. In this case, the gas pipeline 20 is shut off and opened by the shut-off valve 12 instead of the on / off valve 24.

[0050] That is, after the execution of the second timing action (step S15), the control device 11 performs a flow measurement action (step S40) to measure the flow rate by means of the flow meter 25. In the flow measurement action, the control device 11 measures the flow rate of the gas flowing in the gas pipeline 20 downstream of the on-off valve 24 and stores it in memory when the gas pipeline 20 and gas appliance 21 downstream of the on-off valve 24 are not supplied with gas.

[0051] Furthermore, when the gas pressure difference during the flow meter measurement is less than a predetermined pressure difference (step S17: Yes) and the measurement time reaches a predetermined time (step S18: Yes), the control device 11 performs an acquisition action. The aforementioned acquisition action obtains a flow correction value based on the flow rate measured by the flow meter measurement action (step S19). In this way, when the pressure difference is less than the predetermined pressure difference, there is no possibility of gas leakage in the gas pipeline 20, and the gas pipeline 20 has been shut off by the on / off valve 24, the control device 11 obtains the measured flow rate measured by the flow meter measurement action as a gas flow correction value and stores it in memory.

[0052] In the flow meter measurement operation, when the gas flow rate is measured at predetermined time intervals within a predetermined time period, the control device 11 acquires a plurality of measured flow rates. In this case, the control device 11 can also acquire representative values ​​of the plurality of measured flow rates as correction values. These representative values ​​include the average value, median value, and mode of the plurality of measured flow rates.

[0053] In this way, the control device 11 can determine the possibility of gas leakage and obtain the correction value of the gas flow rate when the gas pipeline 20 is shut off by the on / off valve 24. Furthermore, the control device 11 can use this correction value to correct the gas flow rate measured by the flow meter 25, thereby obtaining the gas flow rate with good accuracy in the flow metering process of the gas meter 22.

[0054] <Variation Example 1> In this modified example 1, in embodiments 1 to 3, as shown in FIG1, the gas leak detection device 10 further includes a barometer 17 for measuring atmospheric pressure. The barometer 17 is disposed near the pressure gauge 13 within the housing 22a of the gas meter 22, measures atmospheric pressure, and outputs the measurement to the control device 11.

[0055] In this case, the control device 11 performs the gas leak detection process according to the flowchart shown in Figure 6. In the flowchart of Figure 6, steps S50 to S53 are performed after step S16 in the flowchart of Figure 2. Furthermore, in the flowcharts of Figures 4 and 5, steps S50 to S53 can also be performed after step S16. In the case of Figure 4, the gas pipeline 20 is shut off and opened by the shut-off valve 12 instead of the on / off valve 24.

[0056] In step S16, the control device 11 performs a pressure gauge measurement operation (step S16). During the pressure gauge measurement operation, the control device 11 measures the pressure of the gas in the gas pipeline 20 using the pressure gauge 13, while the gas pipeline 20 is shut off by the on / off valve 24. However, when this measured pressure is a relative pressure, it is sometimes affected by atmospheric pressure. Therefore, the control device 11 performs a barometer measurement operation, which, together with the pressure gauge measurement of the relative pressure of the gas using the pressure gauge 13, measures the atmospheric pressure using the barometer 17 (step S50). In this way, the atmospheric pressure at the time of the relative pressure measurement of the gas is recorded, and these are stored in memory.

[0057] Next, the control device 11 calculates the absolute value of the difference between the predetermined reference pressure and the measured pressure as the pressure difference, and determines whether this pressure difference is less than the predetermined pressure difference (step S51). This reference pressure is the atmospheric pressure corresponding to the reference pressure of the gas, and is the atmospheric pressure measured by the barometer 17 when the reference pressure of the gas is measured by the pressure gauge 13. Furthermore, the measured pressure is the atmospheric pressure corresponding to the measured pressure in the pressure measurement operation of step S16, and is the atmospheric pressure measured in the barometer measurement operation of step S50, which is performed together with the pressure measurement operation, when the gas pressure is measured in the pressure measurement operation.

[0058] Then, the control device 11 determines whether the pressure difference is less than a predetermined pressure difference (step S51). Here, when the control device 11 determines that the pressure difference is less than the predetermined pressure difference (step S51: Yes), the change in atmospheric pressure during the execution of the gas pressure gauge measurement is small. Accordingly, the control device 11 performs the processing after step S17. In this way, when the change in atmospheric pressure has a small impact on the change in gas pressure, since the control device 11 determines the possibility of gas leakage based on the gas pressure difference, it can determine the possibility of gas leakage with better accuracy.

[0059] In contrast, when the control device 11 determines that the pressure difference is above a predetermined pressure difference (step S51: No), the atmospheric pressure change is significant during the execution of the gas pressure gauge measurement. In this case, the change in atmospheric pressure has a greater impact on the gas pressure change during the pressure gauge measurement. Therefore, the control device 11 cannot determine the possibility of gas leakage based on the gas pressure difference measured by the pressure gauge measurement. Thus, the control device 11 determines whether the measurement time in the second measurement action of step S15 has reached a predetermined time, such as 3 minutes (step S52). If the measurement time has not reached the predetermined time (step S52: No), the control device 11 returns to the process in step S16 and repeats the subsequent process. In this way, the control device 11 measures the gas pressure and atmospheric pressure at predetermined time intervals.

[0060] On the other hand, when the pressure difference is above a predetermined pressure difference (step S51: No) and the measurement time reaches a predetermined time (step S52: Yes), the change in atmospheric pressure has a greater impact on the gas pressure difference, making it impossible to determine the possibility of gas leakage based on the gas pressure difference. Accordingly, as shown in the example of FIG7A, the control device 11 displays the determination result of "the change in atmospheric pressure is too large to detect gas leakage" on the display device 14.

[0061] <Variation Example 2> In the above-described variation 1, the control device 11 determines the possibility of a gas leak in the gas leak detection operation when the pressure difference between the predetermined reference pressure and the pressure measured by the pressure gauge is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the atmospheric pressure measured by the barometer and the predetermined reference pressure, i.e., the pressure difference, is less than the predetermined pressure difference. In contrast, in variation 2, the control device 11 can also determine the possibility of a gas leak in the gas leak detection operation when the difference between the predetermined reference total pressure and the total pressure is greater than or equal to a first predetermined difference. The aforementioned total pressure is the sum of the pressure measured by the pressure gauge and the atmospheric pressure measured by the barometer.

[0062] In this case, the control device 11 performs the gas leak detection process according to the flowchart shown in the example of FIG8. In the flowchart of FIG8, the process of step S54 is performed instead of steps S17 and S51~S53 of FIG6.

[0063] In step S16 of Figure 8, during the pressure gauge measurement operation, the control device 11 measures the pressure of the gas in the gas pipeline 20 using the pressure gauge 13, with the gas pipeline 20 shut off by the on / off valve 24. Furthermore, in step S50, during the barometer measurement operation, the control device 11 measures the atmospheric pressure of the gas at the time of measurement using the barometer 17. The control device 11 then calculates the total pressure by adding the gas pressure measured by the pressure gauge operation to the atmospheric pressure measured by the barometer operation. When the gas pressure is a relative pressure based on atmospheric pressure, the total pressure is equivalent to the absolute pressure of the gas.

[0064] Therefore, the control device 11 calculates the total pressure difference by subtracting the calculated total pressure from the predetermined reference total pressure, and determines whether this total pressure difference is less than a first predetermined difference (step S54). Here, if the total pressure difference is less than the first predetermined difference (step S54: Yes), even if the gas pipeline 20 is shut off by the on / off valve 24, the absolute pressure of the gas will not decrease from the reference total pressure or will hardly decrease. Therefore, the control device 11 determines that there is no possibility of gas leakage in the gas pipeline 20 and the gas appliance 21.

[0065] In contrast, when the total pressure difference exceeds a first predetermined difference (step S54: No), the control device 11 shuts off the gas pipeline 20 via the on / off valve 24, causing the absolute pressure of the gas to drop significantly from the reference total pressure. Therefore, the control device 11 determines that there is a possibility of gas leakage in the gas pipeline 20 and the gas appliance 21.

[0066] <Variation Example 3> In Modification 3 disclosed herein, as shown in Embodiments 1-3 and Modification 1, the gas leak detection device 10 further includes a thermometer 18 for measuring temperature. The thermometer 18 is installed in the gas piping 20, measures the gas temperature in the gas piping 20, and outputs the temperature to the control device 11.

[0067] In this case, the control device 11 performs the gas leak detection process according to the flowchart shown in Figure 9. In the flowchart of Figure 9, the processes S60 to S63 are performed after step S16 in the flowchart of Figure 2. Furthermore, in the flowcharts of Figures 4 to 6, the processes S60 to S63 can also be performed after step S16. In the case of Figure 4, the gas pipeline 20 is shut off and opened by the shut-off valve 12 instead of the on / off valve 24.

[0068] In step S16 of Figure 9, the control device 11 performs a pressure measurement operation (step S16), and while the gas pipeline 20 is blocked by the on / off valve 24, the pressure of the gas in the gas pipeline 20 is measured by the pressure gauge 13. However, the gas pressure is sometimes affected by the gas temperature. Therefore, the control device 11 performs a temperature measurement operation, which, together with the pressure measurement operation of the pressure gauge 13, measures the temperature with the thermometer 18 (step S60). In this way, the gas temperature at the time of measurement is measured, and these measurements are stored in memory.

[0069] Next, the control device 11 calculates the absolute value of the difference between the reference temperature and the measured temperature as the temperature difference, and determines whether this temperature difference is less than a predetermined temperature difference (step S61). This reference temperature is the temperature corresponding to the reference pressure of the gas, and is the temperature measured by the thermometer 18 when the reference pressure of the gas is measured by the pressure gauge 13. Furthermore, the measured temperature is the temperature corresponding to the measured pressure in the pressure gauge operation of step S16, and is the temperature measured in the temperature gauge operation of step S60, which is performed together with the pressure gauge operation, when the gas pressure is measured during the pressure gauge operation.

[0070] Then, the control device 11 determines whether the temperature difference is less than a predetermined temperature difference (step S61). Here, when the control device 11 determines that the temperature difference is less than the predetermined temperature difference (step S61: Yes), the temperature change of the gas is small when the gas pressure gauge operation is performed. Accordingly, the control device 11 performs the processing after step S17. In this way, when the temperature change has a small impact on the gas pressure change, since the control device 11 determines the possibility of gas leakage based on the gas pressure difference, it can determine the possibility of gas leakage with better accuracy.

[0071] In contrast, when the control device 11 determines that the temperature difference is greater than a predetermined temperature difference (step S61: No), the temperature change during the execution of the gas pressure gauge measurement is significant. In this case, the temperature change of the gas has a greater impact on the pressure change of the gas during the pressure gauge measurement. Therefore, the control device 11 cannot determine the possibility of gas leakage based on the gas pressure difference measured by the pressure gauge measurement. Therefore, the control device 11 determines whether the measurement time in the second measurement action of step S15 has reached a predetermined time, for example, 3 minutes (step S62). If the measurement time has not reached the predetermined time (step S62: No), the control device 11 returns to the process of step S16 and repeats the subsequent process. In this way, the control device 11 measures the gas pressure and temperature at predetermined time intervals.

[0072] On the other hand, when the temperature difference is greater than a predetermined temperature difference (step S61: No) and the measurement time reaches a predetermined time (step S62: Yes), the temperature change of the gas has a greater impact on the pressure difference of the gas, and the possibility of gas leakage cannot be determined based on the pressure difference of the gas. Accordingly, as shown in the example of FIG7A, the control device 11 displays the determination result of "the temperature change is too large to detect gas leakage" on the display device 14.

[0073] <Variation Example 4> In the above-described variation 3, the control device 11 determines the possibility of a gas leak in the gas leak detection operation when the pressure difference between the predetermined reference pressure and the pressure measured by the pressure gauge is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the temperature measured by the temperature gauge and the predetermined reference temperature (i.e., the temperature difference) is less than a predetermined temperature difference. In contrast, in variation 4, the control device 11 can also determine the possibility of a gas leak in the gas leak detection operation when the difference between the predetermined reference correction pressure and the correction pressure is greater than or equal to a second predetermined difference. The aforementioned correction pressure is a correction pressure that compensates for the pressure measured by the pressure gauge by the temperature measured by the temperature gauge.

[0074] In this case, the control device 11 performs the gas leak detection process according to the flowchart shown in the example of FIG10. In the flowchart of FIG10, the process of step S64 is performed instead of steps S17 and S61~S63 of FIG9.

[0075] In step S16 of Figure 10, during the pressure measurement operation, the control device 11 measures the gas pressure in the gas pipeline 20 using the pressure gauge 13, with the gas pipeline 20 shut off by the on / off valve 24. In step S60, during the temperature measurement operation, the control device 11 measures the gas temperature at the time of the pressure measurement using the thermometer 18. Then, the control device 11 corrects the gas pressure measured by the pressure measurement operation using the temperature measured by the temperature measurement operation, obtaining the gas pressure at a predetermined temperature (e.g., 0 degrees Celsius) as the correction pressure. The relationship between this correction pressure, the gas pressure, and the gas temperature is predetermined and stored in memory.

[0076] Next, the control device 11 calculates the difference between the predetermined reference correction pressure and the obtained correction pressure, and determines whether this difference in correction pressure is less than a second predetermined difference (step S64). This reference correction pressure is the gas pressure at a predetermined temperature (e.g., 0 degrees Celsius), and is predetermined and stored in memory. Here, if the correction pressure difference is less than the second predetermined difference (step S64: Yes), even if the gas pipeline 20 is shut off by the on / off valve 24, the gas correction pressure will not decrease from the reference correction pressure or will hardly decrease. Therefore, the control device 11 determines that there is no possibility of gas leakage in the gas pipeline 20 and the gas appliance 21.

[0077] In contrast, when the difference between the reference correction pressure and the obtained correction pressure is greater than or equal to a second predetermined difference (step S64: No), the control device 11 shuts off the gas pipeline 20 by means of the on / off valve 24, causing the gas correction pressure to drop significantly from the reference correction pressure. Therefore, the control device 11 determines that there is a possibility of gas leakage in the gas pipeline 20 and the gas appliance 21.

[0078] <Variation Example 5> In all the above embodiments and variations, as shown in the example of FIG1, the gas leak detection device 10 is constructed as a single unit. However, as shown in the example of FIG11, the gas leak detection device 10 can also be constructed from a plurality of devices (e.g., a first device 10a and a second device 10b).

[0079] The first device 10a is installed on the gas piping 20 between the on / off valve 24 and the gas appliance 21, for example, using a gas meter 22 as the first device 10a. The first device 10a includes a first control device 11a, and a shut-off valve 12, a pressure gauge 13, a thermometer 18, a flow meter 25, and a first communication interface 15a electrically connected to the first control device 11a. The first communication interface 15a transmits and receives information with external machines and the second device 10b via wireless or wired communication.

[0080] The second device 10b can communicate with the first device 10a and is not installed in the gas piping 20, but rather uses, for example, a user's mobile terminal. The second control device 11b includes a barometer 17, a display device 14, an input device 16, and a second communication interface 15b electrically connected to the second control device 11b. The second communication interface 15b transmits and receives information between the first device 10a and an external machine via wireless or wired communication.

[0081] Furthermore, when a mobile terminal is used as the second device 10b, the second communication interface 15b can also be used as a barometer 17. In this case, the second control device 11b can also obtain information related to air pressure, such as weather information, about the location of the first device 10a through the second communication interface 15b, and obtain the air pressure of the first device 10a based on this air pressure information. This air pressure information and its relationship with air pressure are predetermined and stored in the memory of the second control device 11b.

[0082] The control device 11 of the gas leak detection device 10 includes a first control device 11a for the first device 10a and a second control device 11b for the second device 10b. The first control device 11a is a computer, such as a microcontroller, that controls the electrical machinery of the first device 10a. The second control device 11b is a computer, such as a microcontroller, that controls the electrical machinery of the second device 10b. The first control device 11a and the second control device 11b work together to perform gas leak detection procedures.

[0083] <Gas Leak Detection and Handling> The second control device 11b performs the gas leak detection process according to the flowchart shown in the example of FIG12. In this flowchart of FIG12, step S11' is performed instead of step S11 in FIG2, and the pressure acquisition action of step S16' is performed instead of the pressure measurement action of step S16 in FIG2.

[0084] Specifically, the second control device 11b receives a start instruction for gas leak detection processing from the input device 16 (step S10: Yes) and determines whether the shut-off valve 12 is in the open state (step S11'). This shut-off valve 12 is controlled by the first control device 11a to close and open, and this control content is stored in memory. Therefore, the second control device 11b sends an instruction to obtain the control content of the shut-off valve 12 to the first device 10a via the second communication interface 15b. In response, the first control device 11a sends the control content to the second device 10b via the first communication interface 15a. The second control device 11b determines whether the shut-off valve 12 is in the open state based on this control content. Here, if the shut-off valve 12 is in the closed state (step S11': No), the second control device 11b terminates the gas leak detection processing.

[0085] On the other hand, when the shut-off valve 12 is in the open state (step S11': Yes), a guidance display operation is performed to display guidance information for closing the on / off valve 24 on the display device 14 (step S12). Based on this guidance information, the user performs the valve closing operation of the on / off valve 24, thereby shutting off the gas pipeline 20. Furthermore, the second control device 11b performs the first timing operation (step S13), and when the first predetermined time has elapsed (step S14: Yes), the second timing operation is performed (step S15).

[0086] Next, the second control device 11b performs a pressure acquisition operation, which obtains the gas pressure measured by the pressure gauge 13 during the pressure measurement operation from the first device 10a (step S16'). Here, in order to obtain the gas pressure from the first device 10a, the second control device 11b sends a pressure acquisition instruction to the first device 10a via the second communication interface 15b. In response, the first control device 11a receives the pressure acquisition instruction via the first communication interface 15a and performs a pressure measurement operation accordingly. Then, the first control device 11a measures the gas pressure using the pressure gauge 13 during the pressure measurement operation and sends the measured pressure to the second device 10b via the first communication interface 15a. In this way, the second control device 11b obtains the gas pressure measured during the pressure measurement operation from the second device 10b.

[0087] Next, the second control device 11b performs a gas leak determination operation (step S17) based on the gas pressure measured by the pressure gauge. Here, the second control device 11b calculates the difference between a predetermined reference pressure and the gas pressure measured by the pressure gauge. If this pressure difference is greater than or equal to a predetermined pressure difference (step S17: No), it determines that there is a possibility of gas leakage. Conversely, if the pressure difference is less than a predetermined pressure difference (step S17: Yes) and the measurement time reaches a predetermined time (step S18: Yes), it determines that there is no possibility of gas leakage.

[0088] <Variation Example 6> In Embodiment 2, when a gas leak detection process is performed using a gas leak detection device 10 equipped with a first device 10a and a second device 10b, the second device 10b performs the process according to the flowchart shown in the example of FIG13. In this flowchart of FIG13, steps S11', S16', S30', and S31' are performed instead of steps S11, S16, S30, and S31 in FIG4.

[0089] As described above, the shut-off valve 12 is controlled to close or open by the first control device 11a. Therefore, in step S30', the second control device 11b sends a shut-off instruction for the shut-off valve 12 to the first device 10a. In response to this instruction, the first control device 11a executes shut-off control of the shut-off valve 12, shutting off the gas piping 20. Then, the first control device 11a sends a response confirming the shut-off control of the shut-off valve 12 to the second device 10b. The second control device 11b then executes the processing after step S15 based on this response.

[0090] Furthermore, in step S31', similarly to step S30', the second control device 11b sends an opening instruction for the shut-off valve 12 to the first device 10a. In response, the first control device 11a executes the opening control of the shut-off valve 12, opening the gas piping 20. Then, the first control device 11a sends a response to the executed opening control of the shut-off valve 12 to the second device 10b. The second control device 11b terminates the gas leak detection process based on this response.

[0091] <Variation Example 7> In Embodiment 3, when a gas leak detection process is performed using a gas leak detection device 10 equipped with a first device 10a and a second device 10b, the second device 10b performs the process according to the flowchart shown in the example of FIG14. In this flowchart of FIG14, steps S11', S16', and S40' are performed instead of steps S11, S16, and S40 in FIG5.

[0092] In step S40', the second control device 11b performs a flow acquisition operation, which acquires the gas flow rate measured by the flow meter 25 during the flow meter measurement operation from the first device 10a. Here, in order to acquire the gas flow rate from the first device 10a, the second control device 11b sends a flow acquisition instruction to the first device 10a. The first control device 11a receives the flow acquisition instruction and performs a flow meter measurement operation accordingly. Then, the first control device 11a measures the gas flow rate using the flow meter 25 during the flow meter measurement operation and sends the measurement to the second device 10b. In this way, the second control device 11b acquires the gas flow rate measured during the flow meter measurement operation from the second device 10b.

[0093] <Variation Example 8> In Modification 1, when a gas leak detection process is performed using a gas leak detection device 10 equipped with a first device 10a and a second device 10b, the second device 10b performs the process according to the flowchart shown in the example of FIG15. In this flowchart of FIG15, steps S11' and S16' are performed instead of steps S11 and S16 in FIG6. Furthermore, when the barometer 17 is controlled by the second control device 11b, the second control device 11b performs a barometer measurement operation (step S50) to measure atmospheric pressure using the barometer 17.

[0094] Furthermore, in Modification 2, when the gas leak detection process is performed by the gas leak detection device 10 equipped with the first device 10a and the second device 10b, the second device 10b performs the process according to the flowchart shown in the example of FIG8. However, steps S11' and S16' are performed instead of steps S11 and S16 in FIG8.

[0095] <Variation Example 9> In Modification 3, when a gas leak detection process is performed using a gas leak detection device 10 equipped with a first device 10a and a second device 10b, the second device 10b performs the process according to the flowchart shown in the example of FIG16. In this flowchart of FIG16, steps S11', S16', and S60' are performed instead of steps S11, S16, and S60 in FIG9.

[0096] In step S60', the second control device 11b performs a temperature acquisition operation, which acquires the gas temperature measured by the thermometer 18 during the temperature measurement operation from the first device 10a. Here, in order to acquire the gas temperature from the first device 10a, the second control device 11b sends a temperature acquisition instruction to the first device 10a. The first control device 11a receives the temperature acquisition instruction and performs a temperature measurement operation accordingly. Then, the first control device 11a measures the gas temperature using the thermometer 18 during the temperature measurement operation and sends the measured gas temperature to the second device 10b. In this way, the second control device 11b acquires the gas temperature measured during the temperature measurement operation from the second device 10b.

[0097] Furthermore, in Variation 4, when the gas leak detection process is performed by the gas leak detection device 10 equipped with the first device 10a and the second device 10b, the second device 10b performs the process according to the flowchart shown in the example of FIG10. However, steps S11', S16', and S60' are performed instead of steps S11, S16, and S60 in FIG10.

[0098] <Other variations> In all the above embodiments and variations, the shut-off valve 12 is located upstream of the gas pipeline 20, above the pressure gauge 13. However, when the gas pipeline 20 is shut off and opened by the on / off valve 24, the shut-off valve 12 may also be located downstream of the pressure gauge 13. Even in such a case, the pressure gauge 13 is still located on the gas pipeline 20 between the on / off valve 24 and the gas appliance 21. Thus, the control device 11 can measure the gas pressure in the gas pipeline 20 using the pressure gauge 13 when there is no gas supply to the gas pipeline 20 and gas appliance 21 downstream of the on / off valve 24, and determine the possibility of a gas leak based on this pressure.

[0099] In all the above embodiments and variations, the gas leak detection device 10 includes a display device 14 as an output device. However, the output device is not limited to this. For example, the gas leak detection device 10 may also include a speaker that emits sound and a light source such as an LED that emits light as an output device. These are driven by the control device 11. By means of sound or light, guidance information and judgment results for the guidance output action in the gas leak detection process can be output.

[0100] Furthermore, all the above-described embodiments can be combined with each other as long as they do not exclude each other. From the above description, those skilled in the art should clearly understand many improvements and other embodiments of this disclosure. Therefore, the above description should be interpreted as an example and is provided for the purpose of teaching those skilled in the art the best way to implement this disclosure. Details of its structure and / or function can be substantially changed without departing from the spirit of this disclosure.

[0101] <Note> Based on the above description of the implementation forms, the following technology is revealed. The first technology is a gas leak detection device, which is installed in a gas pipeline that supplies gas to gas appliances and is equipped with an on / off valve. The gas leak detection device includes: a pressure gauge that measures the pressure of gas in the gas pipeline downstream of the on / off valve; an output device that outputs information; and a control device that performs a guide output action to output guide information to close the on / off valve to the output device. After the guide output action is performed, a pressure measurement action is performed to measure the pressure by the pressure gauge. A gas leak determination action is performed to determine the possibility of gas leak based on the pressure measured by the pressure measurement action.

[0102] Based on this configuration, the user operates the valve to close it in response to guidance information from the output device. This allows the user to shut off the gas pipeline by opening and closing the valve, and to determine the likelihood of a gas leak based on the gas pressure within the pipeline.

[0103] The second technology is a gas leak detection device as described in Technology 1, which further has an input device for inputting information. The aforementioned control device executes the aforementioned guidance output action when a start instruction is input through the aforementioned input device.

[0104] Based on this configuration, the user operates the input device to send a start instruction to the control device, which then outputs a guide output in response to this start instruction. In response to this guide output according to the user's intention, a gas pipeline can be shut off by opening and closing a valve, and the possibility of a gas leak can be determined based on the gas pressure in the pipeline.

[0105] The third technology is a gas leak detection device as described in Technology 1 or 2, which includes a barometer for measuring atmospheric pressure. The barometer measures the pressure of gas, i.e., relative pressure, with atmospheric pressure as a predetermined reference. The control device performs the aforementioned pressure measurement operation and the barometer measurement operation for measuring atmospheric pressure using the aforementioned barometer after the execution of the aforementioned guide output operation. When the pressure difference between the predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the atmospheric pressure measured by the aforementioned pressure measurement operation and the predetermined reference pressure, i.e., the pressure difference, is less than the predetermined pressure difference; or when the difference between the predetermined total reference pressure and the total pressure of the aforementioned pressure measured by the aforementioned pressure measurement operation plus the total atmospheric pressure measured by the aforementioned pressure measurement operation is greater than or equal to a first predetermined difference, the aforementioned gas leak determination operation determines that there is a possibility of gas leak.

[0106] Based on this configuration, when the atmospheric pressure difference is small, its impact on the gas pressure difference is relatively small. Therefore, the likelihood of a gas leak can be determined with greater accuracy based on the gas pressure under such conditions. Furthermore, the combined pressure measured by the pressure gauge and the atmospheric pressure measured by the barometer is equivalent to the absolute pressure of the gas. This absolute pressure can be used to determine the likelihood of a gas leak with greater accuracy.

[0107] The fourth technology is a gas leak detection device as described in any one of technologies 1 to 3, which includes a thermometer for measuring temperature. The aforementioned control device performs the aforementioned pressure measurement operation and the temperature measurement operation by measuring temperature using the aforementioned thermometer after the aforementioned guide output operation is executed. When the pressure difference between a predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the aforementioned temperature measured by the aforementioned temperature measurement operation and the predetermined reference temperature, i.e., the temperature difference, is less than a predetermined temperature difference, or when the difference between a predetermined reference correction pressure and the correction pressure after correcting the aforementioned pressure measured by the aforementioned pressure measurement operation by the aforementioned temperature measurement operation is greater than or equal to a second predetermined difference, the aforementioned gas leak determination operation determines that there is a possibility of gas leak.

[0108] Based on this configuration, when the gas temperature difference is small, the effect of the gas temperature difference on the gas pressure difference is relatively small. The probability of a gas leak can be determined with greater accuracy based on the gas pressure under such conditions. Furthermore, by correcting the gas pressure based on temperature, the influence of temperature can be suppressed, and the probability of a gas leak can be determined with greater accuracy based on the corrected gas pressure.

[0109] The fifth technology is a gas leak detection device disposed in a gas pipeline that supplies gas to gas appliances. The gas leak detection device includes: a shut-off valve that shuts off the gas pipeline; a pressure gauge that measures the pressure of gas in the gas pipeline downstream of the shut-off valve; an output device that outputs information; an input device that inputs information; and a control device that, when a start instruction is input from the input device, executes a shut-off action by shutting off the gas pipeline through the shut-off valve; after the shut-off action is executed, executes a pressure measurement action by measuring the pressure through the pressure gauge; and executes a gas leak determination action by determining the possibility of gas leak based on the pressure measured by the pressure measurement action.

[0110] Based on this configuration, the user operates the input device to input a start instruction to the control device, which then controls the shut-off valve to close in response to this start instruction. In response to such a start instruction as intended by the user, the shut-off valve can shut off the gas pipeline, and the probability of a gas leak can be determined based on the gas pressure in the pipeline.

[0111] The sixth technology is a gas leak detection device as described in Technology 5, which includes a barometer for measuring atmospheric pressure. The barometer measures the pressure of gas, i.e., relative pressure, with atmospheric pressure as a predetermined reference. The control device performs the aforementioned pressure measurement operation and the barometer measurement operation to measure atmospheric pressure using the aforementioned barometer after the aforementioned shut-off operation is executed. When the pressure difference between the predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the aforementioned atmospheric pressure measured by the aforementioned pressure measurement operation and the predetermined reference pressure, i.e., the pressure difference, is less than the predetermined pressure difference, the gas leak determination operation determines that there is a possibility of gas leak.

[0112] Based on this structure, when the atmospheric pressure difference is small, the impact of the atmospheric pressure difference on the gas pressure difference is relatively small. Therefore, the likelihood of a gas leak can be determined with greater accuracy based on the gas pressure under such conditions.

[0113] The seventh technology is a gas leak detection device as described in technology 5 or 6, which includes a thermometer for measuring temperature. The aforementioned control device performs the aforementioned pressure measurement operation and the temperature measurement operation by measuring temperature using the aforementioned thermometer after the aforementioned shut-off operation is executed. When the pressure difference between a predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the aforementioned temperature measured by the aforementioned temperature measurement operation and the predetermined reference temperature, i.e., the temperature difference, is less than a predetermined temperature difference, the aforementioned gas leak determination operation determines that there is a possibility of gas leak.

[0114] Based on this structure, when the temperature difference of the gas is small, the temperature difference has a smaller impact on the gas pressure. Therefore, the likelihood of a gas leak can be determined with greater accuracy based on the gas pressure under such conditions.

[0115] The eighth technology is a gas meter comprising: a gas leak detection device as described in any one of technologies 1 to 7; and a flow meter for measuring the flow rate of gas in the aforementioned gas pipeline. The aforementioned control device performs a flow measurement operation by measuring the flow rate using the aforementioned flow meter when the aforementioned pressure measurement operation is executed. When the pressure difference between a predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is less than a predetermined pressure difference, an acquisition operation is performed. The acquisition operation obtains a correction value for the aforementioned flow rate based on the aforementioned flow rate measured by the aforementioned flow meter measurement operation.

[0116] Based on this configuration, when the gas pipeline is shut off by the on / off valve or the shut-off valve, the possibility of gas leakage can be determined based on the gas pressure, and the flow rate correction value can be obtained based on the gas flow rate.

[0117] The ninth technology is a gas leak detection device as described in any one of technologies 1 to 8, comprising: a first device disposed in a gas pipeline supplying gas to gas appliances and equipped with an on / off valve, and having the aforementioned pressure gauge; and a second device capable of communicating with the aforementioned first device and having the aforementioned output device; the aforementioned control device having a first control device of the aforementioned first device and a second control device of the aforementioned second device, the aforementioned first control device performing the aforementioned pressure gauge measurement operation, and the aforementioned second control device performing: a pressure acquisition operation to obtain the aforementioned pressure measured by the aforementioned pressure gauge measurement operation, the aforementioned guide output operation, and the aforementioned gas leak determination operation.

[0118] Based on this configuration, the user can use the second device, located separately from the first device, to determine the possibility of a gas leak. Furthermore, when a gas meter with a pressure gauge is used with the first device, there is no need to incur the cost of installing a separate pressure gauge in addition to the gas meter's pressure gauge; the pressure measurement operation can be performed using the gas meter's pressure gauge. Additionally, when the user's mobile terminal is used with the second device, there is no need to incur the cost of installing a separate output device in addition to the mobile terminal's output device; the guidance output operation can be performed using the mobile terminal's output device.

[0119] 10: Gas Leak Detection Device 10a: Device 1 10b: Device 2 11: Control device 11a: First control device 11b: Second control device 12: Shutdown valve 13: Pressure gauge 14: Display device (output device) 15: Communication Interface 15a: First Communication Interface 15b: Second Communication Interface 16: Input device 17: Barometer 18: Thermometer 20: Gas piping 21: Gas appliances 22: Gas meter 22a: Shell 23: Gas supply source 24: On / off valve 25: Flow meter S10, S11, S11', S12, S13, S14, S15, S16, S16', S17, S18, S19, S20, S30, S30', S31, S31', S40, S40', S41, S50, S51, S52, S53, S54, S60, S60', S61, S62, S63, S64: Steps

Claims

1. A gas leak detection device, disposed in a gas pipeline supplying gas to gas appliances and equipped with an on / off valve, the gas leak detection device comprising: a pressure gauge for measuring the pressure of gas in the gas pipeline downstream of the on / off valve; an output device for outputting information; and a control device, wherein the control device performs a guidance output action to output guidance information for closing the on / off valve to the output device; after the execution of the guidance output action, it performs a pressure measurement action to measure the pressure by the pressure gauge; it performs a gas leak determination action to determine the possibility of gas leak based on the pressure measured by the pressure measurement action; the control device performs a remaining time timing action, wherein the remaining time timing action measures the remaining time from a preset predetermined time and outputs it to the output device; and in the guidance output action performed by the control device, the remaining time is output to the output device in a manner that the remaining time gradually decreases as time passes from the display time of the guidance information.

2. The gas leak detection device of claim 1 further includes an input device for inputting information, and the aforementioned control device executes the aforementioned guidance output action when a start instruction is input through the aforementioned input device.

3. The gas leak detection device of claim 1, which includes a barometer for measuring atmospheric pressure, wherein the barometer measures the relative pressure of gas relative to atmospheric pressure, and the control device performs the aforementioned pressure measurement operation and the barometer measurement operation for measuring atmospheric pressure by means of the aforementioned barometer after the execution of the aforementioned guide output operation, and determines that there is a possibility of gas leak in the aforementioned gas leak determination operation when the pressure difference between the predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the aforementioned atmospheric pressure measured by the aforementioned pressure measurement operation and the predetermined reference pressure is less than the predetermined pressure difference; or when the difference between the predetermined total reference pressure and the total pressure of the aforementioned pressure measured by the aforementioned pressure measurement operation plus the total atmospheric pressure measured by the aforementioned pressure measurement operation is greater than or equal to a first predetermined difference.

4. The gas leak detection device of claim 1, which includes a thermometer for measuring temperature, wherein the aforementioned control device performs the aforementioned pressure measurement action and the temperature measurement action by means of the aforementioned thermometer after the execution of the aforementioned guide output action. When the pressure difference between the predetermined reference pressure and the pressure measured by the aforementioned pressure measurement action is greater than or equal to a predetermined pressure difference, and the absolute value of the difference between the aforementioned temperature measured by the aforementioned temperature measurement action and the predetermined reference temperature, i.e., the temperature difference, is less than a predetermined temperature difference; or when the difference between the predetermined reference correction pressure and the correction pressure after correcting the aforementioned pressure measured by the aforementioned pressure measurement action by means of the aforementioned temperature measurement action is greater than or equal to a second predetermined difference, the aforementioned gas leak determination action determines that there is a possibility of gas leak.

5. The gas leak detection device of claim 1, comprising: a first device disposed in a gas pipeline supplying gas to gas appliances and equipped with an on / off valve, and having the aforementioned pressure gauge; and a second device capable of communicating with the aforementioned first device and having the aforementioned output device; the aforementioned control device comprising a first control device of the aforementioned first device and a second control device of the aforementioned second device; the aforementioned first control device performing the aforementioned pressure gauge measurement operation; and the aforementioned second control device performing: a pressure acquisition operation to obtain the aforementioned pressure measured by the aforementioned pressure gauge measurement operation, the aforementioned guide output operation, and the aforementioned gas leak determination operation.

6. A gas leak detection device, disposed in a gas pipeline supplying gas to gas appliances, the gas leak detection device comprising: a shut-off valve for shutting off the gas pipeline; a pressure gauge for measuring the pressure of gas in the gas pipeline downstream of the shut-off valve; an output device for outputting information; an input device for inputting information; and a control device, wherein the control device, when a start instruction is input from the input device, performs a shut-off action by shutting off the gas pipeline by the shut-off valve if the shut-off valve is in an open state; after the shut-off action is performed, performs a pressure measurement action by measuring the pressure by the pressure gauge; and performs a gas leak determination action by determining the possibility of gas leak based on the pressure measured by the pressure measurement action.

7. The gas leak detection device of claim 6, which includes a barometer for measuring atmospheric pressure, wherein the barometer measures the pressure of gas relative to atmospheric pressure, and the control device performs the aforementioned pressure measurement operation and the barometer measurement operation for measuring atmospheric pressure by means of the aforementioned barometer after the aforementioned shut-off operation is executed, and determines that there is a possibility of gas leak in the aforementioned gas leak determination operation when the pressure difference between the predetermined reference pressure and the aforementioned pressure measured by the aforementioned pressure measurement operation is greater than or equal to the predetermined pressure difference, and the absolute value of the difference between the aforementioned atmospheric pressure measured by the aforementioned pressure measurement operation and the predetermined reference pressure is less than the predetermined pressure difference.

8. The gas leak detection device of claim 6, which includes a thermometer for measuring temperature, wherein the aforementioned control device performs the aforementioned pressure measurement operation and the temperature measurement operation by means of the aforementioned thermometer after the aforementioned shut-off operation is executed, and when the pressure difference between the predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is greater than or equal to the predetermined pressure difference, and the absolute value of the difference between the aforementioned temperature measured by the aforementioned temperature measurement operation and the predetermined reference temperature, i.e., the temperature difference, is less than the predetermined temperature difference, the aforementioned gas leak determination operation determines that there is a possibility of gas leak.

9. A gas meter comprising: a gas leak detection device as described in any one of claims 1 to 8; and a flow meter for measuring the flow rate of gas in the aforementioned gas pipeline, wherein the aforementioned control device performs a flow measurement operation by measuring the flow rate using the aforementioned flow meter when the aforementioned pressure measurement operation is executed; and performs an acquisition operation when the pressure difference between a predetermined reference pressure and the pressure measured by the aforementioned pressure measurement operation is less than a predetermined pressure difference, wherein the acquisition operation obtains a correction value for the aforementioned flow rate based on the aforementioned flow rate measured by the aforementioned flow meter measurement operation.

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