Gas slight leakage detection device and gas slight leakage detection system

Abstract

The present invention provides a method and device for detecting a small amount of gas leakage, which can further consider the surrounding environment (especially the temperature environment) of a gas supply path to improve the accuracy of leakage judgment. The small amount of gas leakage detection device comprises: a gas flow acquisition unit (10) which acquires the flow rate of gas in a gas flow path (3); a pressure detection unit (20); a temperature detection unit (30); an alarm unit (40); and a control unit (50) which counts a flow counter (52C), a pressure-free rise counter (52B), and a temperature rise counter (52A) in each first period, and when the value of the pressure-free rise counter reaches a first specified value, determines whether to make the alarm unit (40) sound an alarm based on the value of the flow counter and the value of the temperature rise counter.

Description

Technical Field

[0001] The invention relates to a gas slight leakage detection device and a gas slight leakage detection system. Background Art

[0002] In the past, for example, high-pressure gas such as LP gas (liquefied propane gas, etc.) contained in a gas tank was supplied to a gas appliance such as a cooking stove through piping. In addition, for example, Patent Document 1 discloses a technology for detecting a slight gas leak in such a gas supply system. Thus, a pressure detection unit is provided in the gas supply path, and when the detection result within a preset period is below a specified value, it is determined that a gas leak has occurred.

[0003] That is, according to Boyle's law and Charles' law, it can be known that, especially in a situation where the gas in the gas supply path is not used but sealed, the gas pressure in the gas supply path changes according to the temperature change of the surrounding environment. Therefore, when the change in gas pressure is very small during a predetermined period (for example, during 1 week), it can be inferred that there is a possibility of leakage somewhere in the gas supply path. In short, if the gas in the gas supply path is continuously observed for a long period of time, pressure changes should occur along with temperature changes. If no large pressure changes occur during this period, it can be inferred that a gas leak has occurred to release the pressure. The technical idea involved in Patent Document 1 is based on this principle.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 4-93739 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, there are also cases where the location where the gas supply path is set is an environment that lacks temperature changes, such as when the gas supply path is buried deep underground. In this case, the temperature of the gas changes little, so even if it is observed for a long time, the pressure change of the gas is small. Therefore, according to the technology of Patent Document 1, even if there is no gas leakage, it will be mistakenly determined that there is a gas leakage based on the condition that the long-term gas pressure change is small. As a result, the maintenance worker goes to the site to perform unnecessary inspections and repairs on the gas supply path, which is undesirable.

[0009] Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas minute leak detection device and a gas minute leak detection system that can further consider the surrounding environment (especially the temperature environment) of the gas supply path to improve the accuracy of leakage judgment.

[0010] Solutions for solving problems

[0011] The gas slight leakage detection device involved in the present invention comprises: a gas flow acquisition unit, which acquires the flow rate of gas in the gas flow path; a pressure detection unit, which detects the gas pressure in the gas flow path; a temperature detection unit, which detects the gas temperature in the gas flow path; an alarm unit; and a control unit, wherein the control unit has: a flow counter, which counts when the flow rate acquired by the gas flow acquisition unit during a specified first period does not become zero, and resets when the flow rate is zero; and a pressure-free rise counter, which counts when the rise value of the gas pressure detected by the pressure detection unit after the flow rate acquired by the gas flow acquisition unit during the first period becomes zero does not become above a specified first pressure threshold, and resets when the pressure-free rise counter When the rising value becomes above the first pressure threshold, the pressure-free rising counter is reset; and when the flow rate acquired by the gas flow acquisition unit in the first period becomes zero and then it is determined that the rising value of the gas temperature detected by the temperature detection unit becomes above the first temperature threshold, the temperature rising counter counts, and when the rising value becomes above the first pressure threshold, the temperature rising counter is reset, and the control unit is configured to execute counting of the flow counter, the pressure-free rising counter and the temperature rising counter in each of the first period, and when the value of the pressure-free rising counter reaches a first specified value, determine whether to make the alarm unit sound an alarm based on the values ​​of the flow counter and the temperature rising counter.

[0012] This structure can improve the accuracy of gas leakage detection. That is, within a first period (e.g., 24 hours), even if the gas pressure rise is less than the first pressure threshold, if the gas temperature hardly changes during this period, the main reason for the small change in gas pressure is inferred to be the small change in gas temperature.

[0013] Therefore, in the gas minute leakage detection device according to the present invention, the counted temperature rise counter value is taken into consideration, thereby making it possible to improve the accuracy of gas leakage detection compared with the invention disclosed in Patent Document 1.

[0014] In addition, the gas slight leakage detection system involved in the present invention comprises: a monitoring center; and a gas slight leakage detection device, which has a gas flow acquisition unit for acquiring the flow rate of gas in the gas flow path, a pressure detection unit for detecting the gas pressure in the gas flow path, a temperature detection unit for detecting the temperature of the gas in the gas flow path, an alarm unit, a wireless module for transmitting and receiving with the monitoring center, and a control unit, wherein the control unit comprises: a flow counter, which counts when the flow rate acquired by the gas flow acquisition unit in a prescribed first period does not become zero, and resets when the flow rate is zero; and a pressure-free rise counter, which counts when the rise value of the gas pressure detected by the pressure detection unit after the flow rate acquired by the gas flow acquisition unit in the first period becomes zero does not become above a prescribed first pressure threshold, and resets when the rise value becomes above the first pressure threshold. In this case, the pressure-free rising counter is reset; and there is a temperature rising counter. When the flow rate acquired by the gas flow acquisition unit becomes zero during the first period and then it is determined that the rising value of the gas temperature detected by the temperature detection unit becomes above the first temperature threshold, the temperature rising counter counts, and when the rising value becomes above the first pressure threshold, the temperature rising counter is reset. The control unit is configured to: execute counting of the flow counter, the pressure-free rising counter and the temperature rising counter in each of the first periods, and when the value of the pressure-free rising counter reaches a first specified value, output a first signal from the wireless module to the monitoring center, the first signal being a signal requesting permission for the alarm unit to issue a warning. The monitoring center is configured to: when the first signal is input from the control unit, determine whether to cause the alarm unit to sound an alarm based on the value of the flow counter and the value of the temperature rising counter.

[0015] This structure can improve the accuracy of gas leakage detection. That is, within a first period (e.g., 24 hours), even if the gas pressure rise is less than the first pressure threshold, if the gas temperature hardly changes during this period, the main reason for the small change in gas pressure is inferred to be the small change in gas temperature.

[0016] Therefore, in the gas minute leakage detection system according to the present invention, the temperature rise counter value obtained by counting is taken into consideration, thereby suppressing false detection of gas leakage and improving the accuracy of gas leakage detection compared with the invention disclosed in Patent Document 1.

[0017] Effects of the Invention

[0018] According to the present invention, it is possible to provide a gas minute leak detection device and a gas minute leak detection system capable of further considering the surrounding environment (particularly the temperature environment) of the gas supply path to improve the accuracy of leakage determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram showing an example of a gas supply system to which the gas minute leakage detection device according to the first embodiment can be applied.

[0020] Figure 2 It is shown Figure 1 A schematic diagram of the schematic structure of a gas minute leak detection device shown.

[0021] Figure 3A This is a flowchart showing an example of the operation of the gas minute leakage detection device according to the first embodiment.

[0022] Figure 3B This is a flowchart showing an example of the operation of the gas minute leakage detection device according to the first embodiment.

[0023] Figure 3C This is a flowchart showing an example of the operation of the gas minute leakage detection device according to the first embodiment.

[0024] Figure 4 1 is a schematic diagram showing a schematic configuration of a gas minute leakage detection system according to the second embodiment.

[0025] Figure 5A This is a flowchart showing an example of the operation of the slight gas leak detection device in the slight gas leak detection system according to the second embodiment.

[0026] Figure 5B This is a flowchart showing an example of the operation of the slight gas leak detection device in the slight gas leak detection system according to the second embodiment.

[0027] Figure 5C This is a flowchart showing an example of the operation of the slight gas leak detection device in the slight gas leak detection system according to the second embodiment.

[0028] Figure 6 This is a flowchart showing an example of the operation of the monitoring center in the gas minute leakage detection system according to the second embodiment.

[0029] Description of Reference Numerals

[0030] 1: Gas storage tank; 2: Pressure adjustment unit; 3: Gas flow path; 5: Gas valve; 6: Gas appliance; 10: Gas flow acquisition unit; 20: Pressure detection unit; 30: Temperature detection unit; 40: Alarm unit; 50: Control unit; 51: Calculation unit; 52A: With temperature rise counter; 52B: Without pressure rise counter; 52C: With flow counter; 52: Storage unit; 53: Wireless module; 60: Control unit; 61: Calculation unit; 62: Storage unit; 63: Wireless module; 100: Gas slight leakage detection device; 110: Monitoring center; 200: Gas supply system; 300: Gas slight leakage detection system. DETAILED DESCRIPTION

[0031] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the following, in all the figures, the same reference numerals are used for the same or equivalent elements, and their repeated descriptions are omitted. In addition, in all the drawings, the components required for explaining the present invention are selected and illustrated, and other components are sometimes omitted from the illustration. Furthermore, the present invention is not limited to the following embodiments.

[0032] (Implementation Method 1)

[0033] The gas slight leakage detection device involved in the present embodiment 1 comprises: a gas flow acquisition unit, which acquires the flow rate of gas in the gas flow path; a pressure detection unit, which detects the gas pressure in the gas flow path; a temperature detection unit, which detects the gas temperature in the gas flow path; an alarm unit; and a control unit, wherein the control unit has: a flow counter, when the flow rate acquired by the gas flow acquisition unit in a specified first period does not become zero, the flow counter counts, and when the flow rate is zero, the flow counter is reset; a pressure rise counter, when the rise value of the gas pressure detected by the pressure detection unit after the flow rate acquired by the gas flow acquisition unit in the first period becomes zero, does not become more than a specified first pressure threshold, the pressure rise counter is reset A pressure-free rising counter is provided for counting, and when the rising value becomes above the first pressure threshold, the pressure-free rising counter is reset; and a temperature-rising counter is provided, and when the flow rate acquired by the gas flow acquisition unit in the first period becomes zero and then it is determined that the rising value of the gas temperature detected by the temperature detection unit becomes above the first temperature threshold, the temperature-rising counter is counted, and when it becomes above the first pressure threshold, the temperature-rising counter is reset. The control unit is constructed as follows: counting of the flow counter, the pressure-free rising counter and the temperature-rising counter is performed in each first period, and when the value of the pressure-free rising counter reaches the first specified value, whether to make the alarm unit sound an alarm is determined based on the values ​​of the flow counter and the temperature rising counter.

[0034] In the gas minute leakage detection device according to the first embodiment, the control unit may be configured to cause the alarm unit to sound an alarm when the value of the non-pressure rise counter reaches the first predetermined value and the value of the temperature rise counter is equal to or greater than the second predetermined value.

[0035] In addition, in the gas slight leakage detection device involved in this embodiment 1, the control unit can also be configured to: when the value of the pressure rise counter reaches the first specified value, the temperature rise counter is less than the second specified value, and the flow counter value is greater than the third specified value, the alarm unit will sound an alarm.

[0036] Furthermore, in the gas minute leakage detection device according to the first embodiment, the control unit may be configured to cause the alarm unit to sound an alarm when the value of the flow rate counter reaches a fourth predetermined value.

[0037] Hereinafter, an example of the gas minute leakage detection device according to the first embodiment will be described in detail with reference to the drawings.

[0038] [Structure of the gas minute leak detection device]

[0039] First, refer to Figure 1 The structure of a gas supply system including the gas minute leakage detection device according to the present embodiment will be described.

[0040] Figure 1 This is a schematic diagram showing an example of a gas supply system to which the gas minute leakage detection device according to the first embodiment can be applied.

[0041] like Figure 1 As shown, in the gas supply system 200, the gas outlet of the gas storage tank 1 containing LP gas or the like is connected to the upstream end of the gas pipe forming the gas flow path 3 via the pressure regulating unit 2. A gas slight leakage detection device 100 is installed in the middle of the gas flow path 3, and the downstream end of the gas flow path 3 is connected to a gas appliance 6 such as a gas stove, for example, via a gas plug 5.

[0042] Next, refer to Figure 2 The gas minute leakage detection device according to the first embodiment will be described.

[0043] Figure 2 It is shown Figure 1 A schematic diagram of the schematic structure of a gas minute leak detection device shown.

[0044] like Figure 2 As shown, the gas minute leakage detection device 100 according to the first embodiment includes a gas flow rate acquisition unit 10 , a pressure detection unit 20 , a temperature detection unit 30 , an alarm unit 40 , and a control unit 50 .

[0045] The gas flow acquisition unit 10 may be composed of, for example, a known flow measurement unit. In addition, the gas flow acquisition unit 10 may be composed of a flow measurement unit and a memory, the memory storing flow information detected by the flow measurement unit and calculated by the control unit 50, or a structure that performs load measurement by transmitting and receiving with a monitoring center. As the flow measurement unit, for example, a flow measurement unit having a transceiver including an ultrasonic vibrator and an oscillation circuit including a crystal oscillator or the like may be used.

[0046] The pressure detector 20 can be a known pressure detector that measures the pressure of the gas flowing through the gas flow path 3. The temperature detector 30 can be a known temperature detector that measures the temperature of the gas flowing through the gas flow path 3.

[0047] In addition, as a temperature detection unit, a form of a separate device for gas leakage detection such as the temperature detection unit 30 illustrated in the present embodiment can be adopted, but it is not limited to this. For example, a form of measuring the temperature of the gas based on the output from a separately provided device can also be adopted. For example, the oscillation frequency of the crystal oscillator or the like possessed by the above-mentioned gas flow acquisition unit 10 has a predetermined temperature characteristic, so by obtaining the relationship between the oscillation frequency and the temperature in advance, the temperature of the gas can be acquired based on the oscillation frequency. In this way, it is possible to acquire the temperature of the gas based on the output (oscillation frequency) of the crystal oscillator of the gas flow acquisition unit 10 without having a dedicated temperature detection unit.

[0048] The alarm unit 40 may be any structure as long as it can notify the outside of the warning. As a method of notifying the outside, for example, it may be a method of displaying text data or image data on the display unit (screen) of the gas micro-leakage detection device 100, or a method of notifying by sound through a speaker or an alarm, or a method of notifying by light or color. In addition, it may be a method of notifying a smartphone, mobile phone, or tablet computer through an email or an application via a communication network.

[0049] The control unit 50 may be composed of a microcomputer, or may be composed of an MPU, a PLC (Programmable Logic Controller), a logic circuit, etc. In addition, the control unit 50 has a computing unit 51 and a storage unit 52. As the computing unit 51, a CPU or the like may be used, and as the storage unit 52, a well-known memory such as a ROM and / or a RAM may be used. Furthermore, by the computing unit 51 executing a prescribed program stored in the storage unit 52, etc., a temperature rise counter 52A, a pressure-free rise counter 52B, and a flow rate counter 52C may be realized.

[0050] [Operation (operation method) and effect of the gas minute leak detection device]

[0051] Next, refer to Figure 1 to Figure 3C The operation and effects of the gas minute leakage detection device according to the first embodiment will be described.

[0052] Figure 3A to Figure 3C : is a flowchart showing an example of the operation of the gas minute leakage detection device involved in this embodiment 1. In addition, in each first period, the calculation unit 51 of the control unit 50 performs the following operations by reading the program stored in the storage unit 52. Here, the first period is a predetermined period set in advance, for example, it can be two hours, twelve hours, twenty-four hours, or it can be a day.

[0053] like Figure 3A to Figure 3C As shown, the control unit 50 obtains the gas flow rate from the gas flow acquisition unit 10 (step S101). Next, the control unit 50 determines whether the gas flow rate becomes zero during the first period based on the gas flow rate obtained in step S101 (step S102). Here, the gas flow rate is zero, which not only means that there is no gas flowing in the gas flow path 3, but also includes a flow rate in which the flow value detected by the gas flow acquisition unit 10 is substantially regarded as zero.

[0054] When the control unit 50 determines that the gas flow rate has not become zero during the first period (step S102: No), the control unit 50 counts the flow counter value (the value of the flow counter) of the flow counter 52C (increases the counter value by 1).

[0055] Next, the control unit 50 obtains the flow counter value obtained by causing the flow counter 52C to count (step S104), and determines whether the obtained flow counter value reaches a fourth predetermined value (step S105). Here, the fourth predetermined value can be set appropriately. For example, when the first period is set to 24 hours (i.e., 1 day) and the judgment is made with 30 days, the fourth predetermined value is set to 30.

[0056] When the control unit 50 determines that the flow counter value obtained in step S104 has reached the fourth predetermined value (step S105: "Yes"), the alarm unit 40 is caused to sound an alarm (step S106). In this case, the alarm unit 40 may be configured to sound an alarm indicating that a gas leak has occurred based on the flow measurement. Thus, the maintenance operator and / or the monitoring center can detect the alarm of the gas leak.

[0057] Next, the control unit 50 resets the flow counter value of the flow counter 52C (initializes the counter value to 0) (step S107), and ends this routine. The flow counter value may be reset by an instruction from a maintenance operator and / or a monitoring center.

[0058] On the other hand, when the control unit 50 determines that the flow counter value obtained in step S104 has not reached the fourth predetermined value (step S105: "No"), the pressure rise counter value (the value of the pressure rise counter) of the pressure rise counter 52B is counted (the counter value is increased by 1; step S113). When the gas is flowing in the gas flow path 3, the pressure value cannot be measured, but from the perspective of redundancy, the pressure rise counter value of the pressure rise counter 52B is counted. In addition, the processing after step S113 will be described later.

[0059] When the control unit 50 determines that the gas flow rate has become zero in the first period based on the gas flow rate acquired in step S101 (step S102 : Yes), it resets the flow rate counter value of the flow rate counter 52C (step S108 ).

[0060] Next, the control unit 50 obtains the gas pressure detected by the pressure detection unit 20 (step S109). Next, the control unit 50 determines whether the gas pressure increase value ΔP during the first period is greater than a predetermined first pressure threshold ΔP1 (e.g., 20 Pascals) based on the gas pressure obtained in step S109 (step S110).

[0061] When the control unit 50 determines that the rising value ΔP of the gas pressure in the first period becomes greater than the first pressure threshold ΔP1 (step S110: "Yes"), the pressure-free rising counter value of the pressure-free rising counter 52B is reset (step S111), and the temperature-rising counter value (the value of the temperature counter) of the temperature-rising counter 52A is reset (step S112), and this program ends.

[0062] On the other hand, when the control unit 50 determines that the rising value ΔP of the gas pressure in the first period is not greater than the first pressure threshold ΔP1 (step S110: "No"), the no-pressure rising counter value of the no-pressure rising counter 52B is counted (the counter value is increased by 1; step S113).

[0063] Next, the control unit 50 acquires the gas temperature detected by the temperature detection unit 30 (step S114). Next, the control unit 50 determines whether the increase value ΔT of the gas temperature in the first period is greater than or equal to a predetermined first temperature threshold ΔT1 (for example, 5°C) based on the gas temperature acquired in step S114 (step S115).

[0064] When the control unit 50 determines that the gas temperature increase value ΔT in the first period is greater than or equal to the predetermined first temperature threshold ΔT1 (step S115: "Yes"), the temperature increase counter value of the temperature increase counter 52A is counted (the counter value is increased by 1; step S116), and the process of step S117 is executed. On the other hand, when the control unit 50 determines that the gas temperature increase value ΔT in the first period is not greater than or equal to the predetermined first temperature threshold ΔT1 (step S115: "No"), the process of step S117 is executed.

[0065] In step S117, the control unit 50 obtains the no-pressure rise counter value obtained by causing the no-pressure rise counter 52B to count. Next, the control unit 50 determines whether the no-pressure rise counter value obtained in step S117 reaches a first predetermined value (step S118). Here, the first predetermined value can be set appropriately. For example, when the first period is set to 24 hours (i.e., 1 day) and the judgment is made in 30 days, the first predetermined value is set to 30.

[0066] When the control unit 50 determines that the non-pressure rise counter value has not reached the preset first specified value (step S118: "No"), the present routine is terminated. On the other hand, when the control unit 50 determines that the non-pressure rise counter value has reached the preset first specified value (step S118: "Yes"), the control unit 50 obtains the temperature rise counter value obtained by causing the temperature rise counter 52A to count (step S119).

[0067] Next, the control unit 50 determines whether the temperature rise counter value obtained in step S119 is greater than a pre-set second predetermined value (step S120). Here, the second predetermined value can be set appropriately. For example, when the first period is set to 24 hours (i.e., 1 day) and the judgment is made over 5 days, the second predetermined value is set to 5.

[0068] When the control unit 50 determines that the temperature rise counter value acquired in step S119 is equal to or greater than the second predetermined value (step S120 : Yes), it causes the alarm unit 40 to sound an alarm (step S121 ), and ends this routine.

[0069] In this case, the alarm unit 40 can be configured to implement an alarm indicating that a gas leak has occurred based on pressure measurement. When the temperature of the gas rises, the gas pressure should rise, so the failure to detect the rise in gas pressure means that it can be determined that the gas may have leaked. Thus, the maintenance operator and / or the monitoring center can detect the alarm of the gas leak.

[0070] Examples of the case where the gas temperature does not rise include a case where the gas supply path is buried deep underground as described above, and a case where the gas minute leakage detection device 100 is installed in a place without sunlight or in a cold region.

[0071] On the other hand, when the control unit 50 determines that the temperature rise counter value is smaller than the second predetermined value (step S120: No), the control unit 50 acquires the flow rate counter value obtained by causing the flow rate counter 52C to count (step S122).

[0072] Next, the control unit 50 determines whether the flow counter value obtained in step S122 is greater than a third predetermined value (step S123). Here, the third predetermined value can be set appropriately. When the first period is set to 24 hours (i.e., 1 day) and 10 days are used for judgment, the third predetermined value is set to 10.

[0073] When the control unit 50 determines that the flow counter value is greater than the third predetermined value (step S123: Yes), the alarm unit 40 sounds an alarm (step S124), and the present routine ends. Thus, the maintenance worker and / or the monitoring center can detect the alarm of gas leakage.

[0074] On the other hand, when the control unit 50 determines that the flow counter value is not greater than the third specified value (step S123: "No"), the pressure-free rise counter value of the pressure-free rise counter 52B is reset (step S125), and the temperature-rising counter value of the temperature-rising counter 52A is reset (step S126), and this procedure is terminated.

[0075] In the gas minute leakage detection device 100 involved in the present embodiment 1 constructed in this way, when the control unit 50 determines that the value of the non-pressure rise counter has reached the first specified value (step S118: "Yes"), it is configured to determine whether to use the alarm unit 40 to issue an alarm based on the value of the flow counter and the value of the temperature rise counter.

[0076] Specifically, when the control unit 50 determines that the temperature rise counter value is greater than the second predetermined value (step S120: "Yes"), the alarm unit 40 is caused to sound an alarm (step S121). When the temperature of the gas rises, the gas pressure should rise. Therefore, although the temperature of the gas rises, the increase in gas pressure cannot be detected, which means that it can be determined that the gas may have leaked.

[0077] In addition, even if the control unit 50 determines that the temperature rise counter value is less than the second predetermined value (step S120: No), when it is determined that the flow counter value is greater than the third predetermined value (step S123: Yes), the alarm unit 40 will sound an alarm (step S124). Since the period of gas circulation in the gas flow path 3 is long, it can be determined that the gas may have leaked.

[0078] Thus, compared with the invention disclosed in Patent Document 1, the accuracy of gas leakage detection can be improved.

[0079] On the contrary, the control unit 50 is configured so that even when the pressure rise counter value does not reach the first specified value (step S118: "Yes"), the alarm unit 40 will not sound an alarm when it is determined that the temperature rise counter value is less than the second specified value (step S120: "No") and when it is determined that the flow counter value is not greater than the third specified value (step S123: "No").

[0080] If the temperature of the gas does not rise, the increase in the gas pressure is not detected, and the period during which the gas flows in the gas flow path 3 is not long, it can be determined that there is no possibility of gas leakage.

[0081] This can suppress unnecessary inspections. Therefore, compared with the invention disclosed in Patent Document 1, it is possible to suppress erroneous detection of gas leakage and improve the accuracy of gas leakage detection.

[0082] In addition, the control unit 50 may be configured to execute the processing of step S114 and step S115 before the processing of step S109 and step S110, and when it is determined that the gas pressure has increased although the gas temperature has not increased, it is considered that the pressure detection unit 20 and / or the temperature detection unit 30 may have failed, and the alarm unit 40 issues a warning. In this way, redundancy can be ensured compared to the invention disclosed in Patent Document 1.

[0083] (Implementation Method 2)

[0084] The gas slight leakage detection system involved in the present embodiment 2 has a monitoring center and a gas slight leakage detection device, and the gas slight leakage detection device has: a gas flow acquisition unit, which acquires the flow rate of gas in the gas flow path; a pressure detection unit, which detects the gas pressure in the gas flow path; a temperature detection unit, which detects the gas temperature in the gas flow path; an alarm unit; a wireless module, which sends and receives with the monitoring center; and a control unit, wherein the control unit has: a flow counter, when the flow rate acquired by the gas flow acquisition unit in a specified first period does not become zero, the flow counter counts, and when the flow rate is zero, the flow counter is reset; a no pressure rise counter, when the rise value of the gas pressure detected by the pressure detection unit after the flow rate acquired by the gas flow acquisition unit in the first period becomes zero, does not become above the specified first pressure threshold, the no pressure rise counter counts The control unit comprises a plurality of control units, a plurality of control units, and a plurality of control units. The plurality of control units have a plurality of control units, and a plurality of control units have ...

[0085] In addition, in the gas minute leakage detection system involved in the present embodiment 2, the monitoring center is configured to obtain the value of the temperature rise counter when a first signal is input from the control unit, and when the acquired value of the temperature rise counter is greater than a second specified value, a permission signal is output to the control unit, and the permission signal is a signal that allows the alarm unit to display an alarm, and the control unit is configured to cause the alarm unit to sound an alarm when the permission signal is input from the monitoring center.

[0086] In addition, in the gas minute leakage detection system involved in the present embodiment 2, it is also possible that the monitoring center is configured to obtain the value of the temperature rise counter and the value of the flow counter when a first signal is input from the control unit, and when the acquired value of the temperature rise counter is less than a second specified value and the value of the flow counter is greater than a third specified value, a permission signal is output to the control unit, and the permission signal is a signal that allows the alarm unit to display an alarm, and the control unit is configured to cause the alarm unit to sound an alarm when the permission signal is input from the monitoring center.

[0087] Furthermore, in the gas minute leakage detection system according to the second embodiment, the control unit may be configured to cause the alarm unit to sound an alarm when the value of the flow rate counter reaches a fourth predetermined value.

[0088] Hereinafter, an example of a gas minute leakage detection system according to the second embodiment will be described in detail with reference to the drawings.

[0089] [Structure of the gas minute leak detection system]

[0090] Figure 4 1 is a schematic diagram showing a schematic configuration of a gas minute leakage detection system according to the second embodiment.

[0091] like Figure 4 As shown, the gas minute leakage detection system 300 according to the second embodiment includes a gas minute leakage detection device 100 and a monitoring center 110 .

[0092] The gas minute leakage detection device 100 has, similarly to the gas minute leakage detection device 100 according to the first embodiment, a gas flow acquisition unit 10, a pressure detection unit 20, a temperature detection unit 30, an alarm unit 40, and a control unit 50, wherein the control unit 50 further has a wireless module 53 for transmitting and receiving with the monitoring center 110. In addition, the gas minute leakage detection device 100 in the second embodiment is similarly configured as the gas minute leakage detection device 100 according to the first embodiment, and therefore a detailed description thereof is omitted.

[0093] The monitoring center 110 includes a control unit 60. The control unit 60 includes a computing unit 61, a storage unit 62, and a wireless module 63 (not shown) for transmitting and receiving information with the gas minute leakage detection device 100. The control unit 60 is configured similarly to the control unit 50 in the gas minute leakage detection device 100, and thus a detailed description thereof is omitted.

[0094] [Operation and effects of the gas minute leak detection system]

[0095] Next, refer to Figures 4 to 6The operation and effects of the gas minute leakage detection system according to the second embodiment will be described.

[0096] Figure 5A to Figure 5C : is a flowchart showing an example of the operation of the gas slight leakage detection device in the gas slight leakage detection system according to Embodiment 2. In addition, in each first period, the calculation unit 51 of the control unit 50 reads the program stored in the storage unit 52 to perform the following operation.

[0097] like Figure 5A to Figure 5C As shown, the control unit 50 obtains the gas flow rate from the gas flow acquisition unit 10 (step S201). Next, the control unit 50 determines whether the gas flow rate becomes zero during the first period based on the gas flow rate obtained in step S201 (step S202). Here, the gas flow rate being zero not only means that there is no gas flowing in the flow path 3, but also includes a flow rate in which the flow value detected by the gas flow acquisition unit 10 is substantially regarded as zero.

[0098] When the control unit 50 determines that the gas flow rate has not become zero during the first period (step S202: No), the control unit 50 counts the flow counter value (the value of the flow counter) of the flow counter 52C (increases the counter value by 1).

[0099] Next, the control unit 50 obtains the flow counter value obtained by causing the flow counter 52C to count (step S204), and determines whether the obtained flow counter value reaches a fourth predetermined value (step S205). Here, the fourth predetermined value can be set appropriately. For example, when the first period is set to 24 hours (i.e., 1 day) and the judgment is made with 30 days, the fourth predetermined value is set to 30.

[0100] When the control unit 50 determines that the flow counter value obtained in step S204 has reached the fourth predetermined value (step S205: "Yes"), the alarm unit 40 is caused to sound an alarm (step S206). In this case, the alarm unit 40 may be configured to sound an alarm indicating that a gas leak has occurred based on the flow measurement. Thus, the maintenance worker and / or the monitoring center can detect the alarm of the gas leak.

[0101] Next, the control unit 50 resets the flow counter value of the flow counter 52C (initializes the counter value to 0) (step S207), and ends this routine. The flow counter value may be reset by an instruction from a maintenance operator and / or a monitoring center.

[0102] On the other hand, when the control unit 50 determines that the flow counter value obtained in step S204 has not reached the fourth specified value (step S205: "No"), the pressure rise counter value (the value of the pressure rise counter) of the pressure rise counter 52B is counted (the counter value is increased by 1; step S213). When the gas is flowing in the gas flow path 3, the pressure value cannot be detected, but from the perspective of redundancy, the pressure rise counter value of the pressure rise counter 52B is counted. In addition, the processing after step S213 will be described later.

[0103] When the control unit 50 determines that the gas flow rate has become zero in the first period based on the gas flow rate acquired in step S201 (step S202 : Yes), it resets the flow rate counter value of the flow rate counter 52C (step S208 ).

[0104] Next, the control unit 50 obtains the gas pressure detected by the pressure detection unit 20 (step S209). Next, the control unit 50 determines whether the gas pressure increase value ΔP during the first period is greater than a predetermined first pressure threshold ΔP1 (e.g., 20 Pascals) based on the gas pressure obtained in step S209 (step S210).

[0105] When the control unit 50 determines that the rising value ΔP of the gas pressure in the first period becomes greater than the first pressure threshold ΔP1 (step S210: "Yes"), the pressure-free rising counter value of the pressure-free rising counter 52B is reset (step S211), and the temperature-rising counter value (the value of the temperature counter) of the temperature-rising counter 52A is reset (step S212), and this program ends.

[0106] On the other hand, when the control unit 50 determines that the increase value ΔP of the gas pressure in the first period is not greater than the first pressure threshold ΔP1 (step S210: "No"), the no-pressure increase counter value of the no-pressure increase counter 52B is counted (the counter value is increased by 1; step S213).

[0107] Next, the control unit 50 acquires the gas temperature detected by the temperature detection unit 30 (step S214). Next, the control unit 50 determines whether the increase value ΔT of the gas temperature in the first period is greater than or equal to a predetermined first temperature threshold ΔT1 (for example, 5°C) based on the gas temperature acquired in step S214 (step S215).

[0108] When the control unit 50 determines that the gas temperature increase value ΔT in the first period is greater than or equal to the first temperature threshold ΔT1 (step S215: "Yes"), the temperature increase counter value of the temperature increase counter 52A is counted (the counter value is increased by 1; step S216), and the process of step S217 is executed. On the other hand, when the control unit 50 determines that the gas temperature increase value ΔT in the first period is not greater than or equal to the first temperature threshold ΔT1 (step S215: "No"), the process of step S217 is executed.

[0109] In step S217, the control unit 50 acquires the no-pressure increase counter value obtained by causing the no-pressure increase counter 52B to count. Next, the control unit 50 determines whether the no-pressure increase counter value acquired in step S217 has reached a preset first predetermined value (step S218).

[0110] When the control unit 50 determines that the value of the pressure-free increase counter has not reached the preset first specified value (step S218: "No"), this routine ends. On the other hand, when the control unit 50 determines that the value of the pressure-free increase counter has reached the preset first specified value (step S218: "Yes"), the processing of step S219 is executed.

[0111] In step S219 , the control unit 50 outputs a first signal to the monitoring center 110 via the wireless module 53 , the first signal being a signal requesting permission for the alarm unit 40 to issue an alarm.

[0112] Here, refer to Figure 6 The operation of the monitoring center 110 after the first signal is input will be described.

[0113] Figure 6 1 is a flowchart showing an example of the operation of the monitoring center in the gas minute leakage detection system according to Embodiment 2. The following operation is executed by the calculation unit 61 of the control unit 60 reading out the program stored in the storage unit 62 .

[0114] like Figure 6 As shown, the control unit 60 of the monitoring center 110 determines whether the first signal is input from the control unit 50 of the gas minute leakage detection device 100 (step S301). When the control unit 60 determines that the first signal is not input from the control unit 50 (step S301: "No"), the process of step S301 is executed again, for example, after 50 msec.

[0115] On the other hand, when the control unit 60 determines that the first signal is input from the control unit 50 (step S301: "Yes"), the temperature rise counter value obtained by counting the temperature rise counter 52A of the gas minute leakage detection device 100 is obtained via the wireless module 63 and the wireless module 53 (step S302).

[0116] Next, the control unit 60 determines whether the temperature rise counter value obtained in step S302 is greater than the second specified value (step S303). When the control unit 60 determines that the temperature rise counter value is greater than the second specified value (step S303: "Yes"), it outputs a signal that allows the alarm unit 40 to issue an alarm, i.e., a permission signal (step S304), and ends this program.

[0117] On the other hand, when the control unit 60 determines that the temperature rise counter value is less than the second predetermined value (step S303: No), the flow counter value obtained by the flow counter 52C is obtained (step S305). Next, the control unit 50 determines whether the flow counter value obtained in step S305 is greater than a preset third predetermined value (step S306).

[0118] When the control unit 50 determines that the flow counter value is greater than the third predetermined value (step S306: "Yes"), it outputs a permission signal (step S307) and ends this program. On the other hand, when the control unit 50 determines that the flow counter value is not greater than the third predetermined value (step S306: "No"), it outputs a disallowance signal (step S308) and ends this program.

[0119] After receiving the operation of the monitoring center 110, the control unit 50 of the gas minute leakage detection device 100 executes the operation (processing) after step S220 as follows.

[0120] like Figure 5C As shown, after the control unit 50 outputs the first signal to the monitoring center 110 (step S219), it determines whether a signal is input from the monitoring center 110 (step S220).

[0121] When the control unit 50 determines that no signal is input from the monitoring center 110 (step S220: No), the time is measured by the timer (step S221). Next, the control unit 50 determines whether the time elapsed from the output of the first signal to the monitoring center 110 has passed the second period based on the time information obtained in step S221 (step S222). Here, the second period is a predetermined period set in advance, for example, 5 minutes or 1 hour.

[0122] When the control unit 50 determines that the time elapsed from the output of the first signal to the monitoring center 110 has not passed the second period (step S222: "No"), it returns to the processing of step S220, and executes the processing of steps S220 to S222 in a state where no signal is input from the monitoring center 110 until the time elapsed from the output of the first signal to the monitoring center 110 has passed the second period.

[0123] On the other hand, when the control unit 50 determines that the time elapsed from the output of the first signal to the monitoring center 110 exceeds the second period (step S222: Yes), it causes the alarm unit 40 to issue an alarm (step S223), and ends this routine.

[0124] In addition, when the control unit 50 determines that a signal is input from the monitoring center 110 (step S220: Yes), it determines whether the input signal is a permission signal or a non-permission signal (step S224). When the control unit 50 determines that the signal input from the monitoring center 110 is a permission signal, it causes the alarm unit 40 to output an alarm (step S225), and ends this program.

[0125] On the other hand, when the control unit 50 determines that the signal input from the monitoring center 110 is a non-permit signal, the alarm unit 40 is not caused to output an alarm (step S226). Next, the control unit 50 resets the non-pressure rise counter value of the non-pressure rise counter 52B (step S227), resets the temperature rise counter value of the temperature rise counter 52A (step S228), and ends this routine.

[0126] The gas minute leak detection system 300 according to the second embodiment configured in this manner can also achieve the same operational effects as the gas minute leak detection device 100 according to the first embodiment.

[0127] According to the above description, many improvements or other embodiments of the present invention are obvious to those skilled in the art. Therefore, the above description should be interpreted as an illustrative description only, and the best form of the present invention is provided for the purpose of teaching to those skilled in the art. Without departing from the present invention, the details of its structure and / or function can be substantially changed. In addition, various inventions can be formed by appropriate combinations of multiple constituent elements disclosed in the above embodiments.

[0128] Industrial Applicability

[0129] The gas slight leakage detection device and gas slight leakage detection system involved in the present invention can further consider the surrounding environment (especially the temperature environment) of the gas supply path, and can improve the accuracy of leakage judgment. Therefore, the gas slight leakage detection device and gas slight leakage detection system involved in the present invention are useful.

Claims

1. A gas slight leakage detection device, comprising: a gas flow rate acquisition unit for acquiring the flow rate of the gas in the gas flow path; a pressure detection unit configured to detect the gas pressure in the gas flow path; a temperature detection unit configured to detect a temperature of gas in the gas flow path; Alarm Department; as well as Control Department, Wherein, the control unit has: a flow counter, which counts when the flow rate acquired by the gas flow acquisition unit does not become zero during a predetermined first period, and resets when the flow rate becomes zero; a no-pressure rise counter, which counts when the rising value of the gas pressure detected by the pressure detection unit after the flow rate acquired by the gas flow acquisition unit becomes zero during the first period does not become greater than a prescribed first pressure threshold, and resets when the rising value becomes greater than the first pressure threshold; and There is a temperature rise counter, when it is determined that the rise value of the gas temperature detected by the temperature detection unit becomes greater than a first temperature threshold after the flow rate acquired by the gas flow acquisition unit becomes zero during the first period, the temperature rise counter counts, and when the rise value of the gas pressure detected by the pressure detection unit becomes greater than the first pressure threshold, the temperature rise counter is reset, The control unit is configured to execute counting of the flow rate counter, the pressure-free rise counter, and the temperature rise counter during each of the first periods. Furthermore, when the value of the non-pressure rise counter reaches a first predetermined value, it is determined whether to cause the alarm unit to sound an alarm based on the value of the flow rate counter and the value of the temperature rise counter.

2. The gas slight leakage detection device according to claim 1, wherein: The control unit is configured to cause the alarm unit to issue an alarm when the value of the non-pressure rise counter reaches the first predetermined value and the temperature rise counter is equal to or greater than a second predetermined value.

3. The gas slight leakage detection device according to claim 1 or 2, wherein: The control unit is configured to cause the alarm unit to sound an alarm when the value of the non-pressure rise counter reaches the first predetermined value, the temperature rise counter is less than the second predetermined value, and the flow rate counter has a value greater than or equal to a third predetermined value.

4. The gas minute leakage detection device according to any one of claims 1 to 3, wherein: The control unit is configured to cause the alarm unit to issue an alarm when the value of the flow rate counter reaches a fourth predetermined value.

5. A gas slight leakage detection system, comprising: Monitoring centre; and A gas slight leakage detection device, comprising a gas flow acquisition unit for acquiring the flow rate of gas in a gas flow path, a pressure detection unit for detecting the gas pressure in the gas flow path, a temperature detection unit for detecting the temperature of the gas in the gas flow path, an alarm unit, a wireless module for transmitting and receiving with the monitoring center, and a control unit, in, The control unit has: a flow counter, which counts when the flow rate acquired by the gas flow acquisition unit does not become zero during a predetermined first period, and resets when the flow rate becomes zero; a no-pressure rise counter, which counts when the rising value of the gas pressure detected by the pressure detection unit after the flow rate acquired by the gas flow acquisition unit becomes zero during the first period does not become greater than a prescribed first pressure threshold, and resets when the rising value becomes greater than the first pressure threshold; as well as There is a temperature rise counter, when it is determined that the rise value of the gas temperature detected by the temperature detection unit becomes greater than a first temperature threshold after the flow rate acquired by the gas flow acquisition unit becomes zero during the first period, the temperature rise counter counts, and when the rise value of the gas pressure detected by the pressure detection unit becomes greater than the first pressure threshold, the temperature rise counter is reset, The control unit is configured to execute counting of the flow rate counter, the pressure-free rise counter, and the temperature rise counter during each of the first periods. When the value of the pressure-free rise counter reaches a first predetermined value, a first signal is output from the wireless module to the monitoring center, the first signal being a signal requesting permission for the alarm unit to issue a warning. The monitoring center is configured to determine whether to cause the alarm unit to sound an alarm based on the value of the flow rate counter and the value of the temperature rise counter when the first signal is input from the control unit.

6. The gas slight leakage detection system according to claim 5, wherein: The monitoring center is configured to obtain the value of the temperature rise counter when the first signal is input from the control unit, and output a permission signal to the control unit when the obtained value of the temperature rise counter is greater than a second specified value, the permission signal being a signal that allows the alarm unit to display an alarm, The control unit is configured to cause the alarm unit to issue an alarm when the permission signal is input from the monitoring center.

7. The gas slight leakage detection system according to claim 5 or 6, wherein: The monitoring center is configured to obtain the value of the temperature rise counter and the value of the flow counter when the first signal is input from the control unit, and output a permission signal to the control unit when the obtained value of the temperature rise counter is less than a second specified value and the value of the flow counter is greater than a third specified value, wherein the permission signal is a signal that allows the alarm unit to display an alarm. The control unit is configured to cause the alarm unit to issue an alarm when the permission signal is input from the monitoring center.

8. The gas slight leakage detection system according to any one of claims 5 to 7, wherein: The control unit is configured to cause the alarm unit to issue an alarm when the value of the flow rate counter reaches a fourth predetermined value.

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