Gas meter

Abstract

To provide a gas meter that restrains frequency occurrence of an alarm at the time of abnormality and can be provided with an optimum protection function according to the amount of use of gas in a consumer's house.SOLUTION: A control section of a gas meter has a determination value update section for updating a first abnormality determination lower-limit value to a second abnormality determination lower-limit value that is smaller than the first abnormality determination lower-limit value and is smaller than the maximum value and updates a first abnormality determination upper-limit value to a second abnormality determination upper-limit value that is smaller than the first abnormality determination upper-limit value and is larger than the maximum value during a second predetermined period when the maximum during a first predetermined period is less than the first abnormality determination lower-limit value, and updates the first abnormality determination lower-limit value to a third abnormality determination lower-limit value that is larger than the first abnormality determination lower-limit value and is smaller than the maximum value and updates the first abnormality determination upper-limit value to a third abnormality determination upper-limit value that is larger than the first abnormality determination upper-limit value and is larger than the maximum value during the second predetermined period when the maximum value is equal to or larger than the first abnormality determination upper-limit value during the first predetermined period.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to gas meters. [Background technology]

[0002] Conventionally, a gas safety device is known that learns the normal amount of gas used and varies the gas cutoff level in the event of an abnormality in conjunction with this (Patent Document 1).

[0003] In the gas safety device, if the initial gas usage is, for example, 2.5L, the abnormality determination level, which is the gas cutoff level, is set to Level A. However, if the actual gas usage is determined to be Level B, which is less than 2.5L, leaving the abnormality determination level at Level A will make it difficult to cut off the gas supply. Therefore, the abnormality determination level is changed from Level A to Level C, which is lower than Level A. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-066172 Summary of the Invention [Problem to be solved by the invention]

[0005] However, because the above-mentioned conventional gas safety devices are configured to change the abnormality judgment level based on the gas grade, in areas where gas supply equipment with a limited number of grades is used, the learning effect of the abnormality judgment level is small and it is difficult to provide optimal safety functions according to the amount of gas used.In addition, because the abnormality judgment value is frequently changed based on the gas grade, there is a problem that the amount of gas used can easily exceed the abnormality judgment value, causing frequent alarms in the event of an abnormality.

[0006] The present disclosure aims to provide a gas meter that can be equipped with optimal safety functions according to the amount of gas used in a consumer's home while suppressing the frequent issuance of alarms in the event of an abnormality. [Means for solving the problem]

[0007] A gas meter according to the present disclosure includes a measuring unit that is provided in a gas supply pipe and that measures the flow rate of gas flowing through the gas supply pipe; a storage unit that stores in advance a first abnormality determination lower limit value and a first abnormality determination upper limit value that are values ​​for determining an abnormality and are compared with a maximum value of the gas flow rate during a predetermined period; and a control unit, wherein the control unit does not update the first abnormality determination lower limit value and the first abnormality determination upper limit value when the maximum value during a first predetermined period is equal to or greater than the first abnormality determination lower limit value and less than the first abnormality determination upper limit value, and when the maximum value during the first predetermined period is less than the first abnormality determination lower limit value, during a second predetermined period that is the predetermined period following the first predetermined period: and a judgment value update unit that updates the first abnormality determination lower limit value to a second abnormality determination lower limit value that is smaller than the first abnormality determination lower limit value and smaller than the maximum value, and updates the first abnormality determination upper limit value to a second abnormality determination upper limit value that is smaller than the first abnormality determination upper limit value and larger than the maximum value, and if the maximum value is equal to or larger than the first abnormality determination upper limit value during the first predetermined period, updates the first abnormality determination lower limit value to a third abnormality determination lower limit value that is larger than the first abnormality determination lower limit value and smaller than the maximum value, and updates the first abnormality determination upper limit value to a third abnormality determination upper limit value that is larger than the first abnormality determination upper limit value and larger than the maximum value during the second predetermined period.

[0008] According to the present disclosure, if the maximum value is less than the first abnormality determination lower limit during the first predetermined period, the first abnormality determination lower limit is updated to the second abnormality determination lower limit and the first abnormality determination upper limit is updated to the second abnormality determination upper limit during the second predetermined period. Furthermore, if the maximum value is equal to or greater than the first abnormality determination upper limit during the first predetermined period, the first abnormality determination lower limit is updated to the third abnormality determination lower limit and the first abnormality determination upper limit is updated to the third abnormality determination upper limit during the second predetermined period. This allows the abnormality determination lower limit and the abnormality determination upper limit to be flexibly updated according to the gas flow rate used by the consumer's home. Therefore, it is possible to provide an optimal safety function according to the gas usage amount of the consumer's home. Specifically, an alarm or the like can be issued based on the abnormality determination value optimized for each consumer's home for a gas usage amount that is greater than the normal gas usage amount but less than the abnormal high flow rate, which is the amount of gas usage that occurs when a gas appliance or hose, etc., is damaged but not the gas supply pipe, i.e., a gas usage amount that is greater than the normal gas usage amount but less than the abnormal high flow rate.

[0009] Furthermore, compared to when a range consisting of the first abnormality determination lower limit and the first abnormality determination upper limit is used, the maximum gas flow rate is less likely to deviate from the range consisting of the second abnormality determination lower limit and the second abnormality determination upper limit. Therefore, it is possible to prevent frequent alarms from being issued when, for example, an increase in gas appliances upstream of a customer's home where a gas meter is installed occurs, or when the gas flow rate that should be supplied to the customer's home is not being supplied due to damage to a gas appliance or hose, etc., but not to damage to the gas supply pipe Pg (i.e., when times are different from normal). Furthermore, compared to when a range consisting of the first abnormality determination lower limit and the first abnormality determination upper limit is used, the maximum gas flow rate is less likely to deviate from the range consisting of the third abnormality determination lower limit and the third abnormality determination upper limit. Therefore, for example, when an increase in the number of gas appliances downstream of a customer's home where a gas meter is installed occurs, or when a gas flow rate greater than the amount that should be supplied to the customer's home is supplied due to damage to gas appliances or hoses, etc., even though the gas supply pipe Pg is not damaged (i.e., when times are different from normal), the occurrence of frequent alarms can be reduced. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a gas meter that can be equipped with optimal safety functions according to the amount of gas used in a consumer's home while suppressing the frequent issuance of alarms in the event of an abnormality. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram showing the configuration of a gas meter according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the relationship between the amount of gas used and the elapsed time. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters or redundant description of substantially identical configurations may be omitted. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] 1 is a block diagram showing the configuration of a gas meter 1 according to this embodiment. As shown in FIG. 1, the gas meter 1 includes a shutoff unit 2, a control unit 3, a flow rate measurement unit 4, a storage unit 8, and an external communication unit 9.

[0014] The control unit 3 is, for example, a CPU (Central Processing Unit) and has a flow rate calculation unit 5, a judgment value update unit 6, and a notification unit 7. The flow rate calculation unit 5, the judgment value update unit 6, and the notification unit 7 are functional components that are functionally realized when the CPU executes a predetermined program. The flow rate measurement unit 4 and the flow rate calculation unit 5 correspond to the measurement unit of the present disclosure.

[0015] The gas meter 1 is installed in a gas supply pipe Pg. A portion of the gas supply pipe Pg downstream of the gas meter 1 is connected to various gas appliances (not shown) installed in each customer's home.

[0016] The shutoff unit 2 is provided in a portion of the gas supply pipe Pg upstream of the flow rate measurement unit 4. In response to an instruction from the control unit 3, the shutoff unit 2 shuts off the gas supply pipe Pg in the event of an abnormality, thereby stopping the supply of gas.

[0017] The flow rate measuring unit 4 is provided in the gas supply pipe Pg at a portion downstream of the shutoff unit 2. The flow rate measuring unit 4 can employ a known configuration, for example, a configuration in which the flow rate measuring unit 4 measures the flow rate using a pair of ultrasonic sensors that transmit ultrasonic waves toward the gas flowing through the gas supply pipe Pg and receive the ultrasonic waves after they have propagated.

[0018] The flow rate calculation unit 5 calculates the propagation time difference of ultrasonic waves generated by the gas flowing through the gas supply pipe Pg, and measures the instantaneous flow rate of the gas at predetermined intervals (e.g., 2 seconds) based on the propagation time difference. Then, the flow rate calculation unit 5 calculates the gas flow rate value based on the obtained instantaneous flow rate. In this embodiment, the flow rate calculation unit 5 calculates the gas flow rate value at multiple predetermined periods.

[0019] The storage unit 8 includes, for example, at least one of a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, etc. The storage unit 8 stores in advance a fixed lower limit value Thf (described later), as well as an abnormality determination lower limit value Th1L and an abnormality determination upper limit value Th1H (described later), which are values ​​for determining an abnormality and are compared with the maximum value of the gas flow rate in a predetermined period.

[0020] The determination value update unit 6 determines at predetermined intervals whether or not to update the abnormality determination lower limit value Th1L and the abnormality determination upper limit value Th1H, and updates the abnormality determination lower limit value Th1L and the abnormality determination upper limit value Th1H when predetermined conditions are met. Details will be described later.

[0021] The notification unit 7 notifies an external device (for example, a center server) via the external communication unit 9 that the determination value update unit 6 has updated the respective abnormality determination lower limit values ​​and the respective abnormality determination upper limit values.

[0022] Next, a specific description will be given of the processing performed by the judgment value update unit 6. Fig. 2 is a diagram showing an example of the relationship between the amount of gas used and the elapsed time.

[0023] When a predetermined condition is satisfied in a first predetermined period as a predetermined period, the determination value update unit 6 updates the abnormality determination lower limit value Th1L and the abnormality determination upper limit value Th1H in a second predetermined period following the first predetermined period.

[0024] Here, the first predetermined period of the present disclosure may be a period immediately preceding the second predetermined period, and the second predetermined period of the present disclosure may be a period immediately following the first predetermined period. Therefore, as described below, the first predetermined period and the second predetermined period may have various start and end points in terms of timing. Therefore, to facilitate understanding, the first predetermined period and the second predetermined period are written in parentheses in the following description. Furthermore, the first abnormality determination lower limit value, the first abnormality determination upper limit value, the second abnormality determination lower limit value, the second abnormality determination upper limit value, the third abnormality determination lower limit value, and the third abnormality determination upper limit value of the present disclosure are also written in parentheses.

[0025] 2, during a period starting at time t0 and ending at time t1 (corresponding to a first predetermined period), the maximum value of the gas flow rate is less than the fixed lower limit value Thf. In this case, the judgment value update unit 6 does not update the abnormality judgment lower limit value Th1L and the abnormality judgment upper limit value Th1H during a period starting at time t1 and ending at time t2 (corresponding to a second predetermined period). Note that the lengths of the first predetermined period and the second predetermined period are, for example, the same.

[0026] On the other hand, during a period (corresponding to a first predetermined period) that starts at timing t1 and ends at timing t2, the maximum value of the gas flow rate is equal to or greater than the fixed lower limit value Thf and less than the abnormality determination lower limit value Th1L (corresponding to the first abnormality determination lower limit value). In this case, the determination value update unit 6 performs the following process during a period (corresponding to a second predetermined period) that starts at timing t2 and ends at timing t3. That is, during the second predetermined period, the determination value update unit 6 updates the abnormality determination lower limit value Th1L to an abnormality determination lower limit value Th2L (corresponding to a second abnormality determination lower limit value) that is smaller than the abnormality determination lower limit value Th1L and smaller than the maximum value, and updates the abnormality determination upper limit value Th1H (corresponding to the first abnormality determination upper limit value) to an abnormality determination upper limit value Th2H (corresponding to the second abnormality determination upper limit value) that is smaller than the abnormality determination upper limit value Th1H and greater than the maximum value.

[0027] The abnormality determination upper limit value Th2H may be, for example, a value obtained by multiplying the maximum value by 20% and adding the value to the maximum value. The abnormality determination lower limit value Th2L may be, for example, a value obtained by multiplying the maximum value by 20% and subtracting the value obtained by multiplying the maximum value by 20% from the maximum value. The determination value update unit 6 stores the abnormality determination upper limit value Th2H and the abnormality determination lower limit value Th2L in the memory unit 8.

[0028] When the abnormality determination lower limit value Th1L and the abnormality determination upper limit value Th1H are updated as described above, the notification unit 7 notifies the outside (for example, a center server) via the external communication unit 9 that the update has been performed.

[0029] Next, in a period starting at t2 and ending at t3 (corresponding to a first predetermined period), the maximum value is equal to or greater than the abnormality determination lower limit Th2L (corresponding to the first abnormality determination lower limit) and less than the abnormality determination upper limit Th2H (corresponding to the first abnormality determination upper limit). In such a case, the determination value update unit 6 does not update the abnormality determination lower limit Th2L and the abnormality determination upper limit Th2H in the period starting at t3 and ending at t4 (corresponding to a second predetermined period).

[0030] Furthermore, during the period starting at timing t3 and ending at timing t4 (corresponding to the first predetermined period), the maximum value is equal to or greater than the abnormality determination lower limit value Th2L (corresponding to the first abnormality determination lower limit value) and less than the abnormality determination upper limit value Th2H (corresponding to the first abnormality determination upper limit value). In this case, the determination value update unit 6 temporarily determines not to update the abnormality determination lower limit value Th2L and the abnormality determination upper limit value Th2H during the period starting at timing t4 and ending at timing t5 (corresponding to the second predetermined period).

[0031] Here, at timing ta1 within the period (corresponding to the first predetermined period) starting from timing t4 and ending at timing t5, the maximum value is equal to or greater than the abnormality determination upper limit value Th2H (corresponding to the first abnormality determination upper limit value).

[0032] In such a case, the determination value update unit 6 ends the first predetermined period midway and starts a second predetermined period (i.e., a period that starts at timing ta2 and ends at timing t5a in FIG. 2 ) at timing ta2 immediately after timing ta1. At the same time, during the second predetermined period, the determination value update unit 6 updates the abnormality determination lower limit Th2L (corresponding to the first abnormality determination lower limit) to an abnormality determination lower limit Th3L (corresponding to the third abnormality determination lower limit) that is greater than the abnormality determination lower limit Th2L and less than the maximum value. Additionally, during the second predetermined period, the determination value update unit 6 updates the abnormality determination upper limit Th2H (corresponding to the first abnormality determination upper limit) to an abnormality determination upper limit Th3H (corresponding to the third abnormality determination upper limit) that is greater than the abnormality determination upper limit Th2H and greater than the maximum value. The length of the period that starts at timing ta2 and ends at timing t5a is the same as the lengths of the other predetermined periods.

[0033] The abnormality determination upper limit value Th3H may be, for example, a value obtained by multiplying the maximum value by 20% and adding the value to the maximum value. The abnormality determination lower limit value Th3L may be, for example, a value obtained by multiplying the maximum value by 20% and subtracting the value obtained by multiplying the maximum value by 20% from the maximum value. The determination value update unit 6 stores the abnormality determination upper limit value Th3H and the abnormality determination lower limit value Th3L in the memory unit 8.

[0034] When the abnormality determination lower limit value Th2L and the abnormality determination upper limit value Th2H are updated as described above, the notification unit 7 notifies the outside (for example, a center server) via the external communication unit 9 that the update has been performed.

[0035] In this embodiment, the abnormality determination lower limit values ​​Th1L, Th2L, and Th3L are equal to or greater than the fixed lower limit value Thf.

[0036] As described above, in the gas meter 1 of this embodiment, the determination value update unit 6 updates the abnormality determination lower limit value Th1L to the abnormality determination lower limit value Th2L and updates the abnormality determination upper limit value Th1H to the abnormality determination upper limit value Th2H during the period starting at time t2 and ending at time t3. Furthermore, the determination value update unit 6 updates the abnormality determination lower limit value Th2L to the abnormality determination lower limit value Th3L and updates the abnormality determination upper limit value Th2H to the abnormality determination upper limit value Th3H during the period starting at time t4 and ending at time t5. This allows the abnormality determination lower limit value and the abnormality determination upper limit value to be flexibly updated depending on the gas flow rate used by the consumer's home. This makes it possible to provide optimal safety functions depending on the amount of gas used by the consumer's home. Specifically, an alarm can be issued based on an abnormality judgment value optimized for each consumer's home for a flow rate that occurs when a gas appliance or hose is damaged, even if the gas supply pipe Pg is not damaged, i.e., a gas usage rate that is greater than normal gas usage but less than the high flow rate that occurs during an abnormality.

[0037] Furthermore, from the perspective of gas usage trends at the consumer's home, the maximum gas flow rate is less likely to deviate from the range defined by the abnormality determination lower limit Th2L and the abnormality determination upper limit Th2H. Therefore, for example, when an increase in gas appliances upstream of the consumer's home where the gas meter is installed, or when the gas flow rate that should be supplied to the consumer's home is not being supplied due to damage to gas appliances, hoses, etc., but not to damage to the gas supply pipe Pg (i.e., when times are different from normal), it is possible to prevent frequent alarms from being generated. Furthermore, from the perspective of gas usage trends at the consumer's home, the maximum gas flow rate is less likely to deviate from the range defined by the abnormality determination lower limit Th3L and the abnormality determination upper limit Th3H. Therefore, for example, when an increase in gas appliances downstream of the consumer's home where the gas meter is installed, or when a gas flow rate that is higher than the required gas flow rate is being supplied to the consumer's home due to damage to gas appliances, hoses, etc., but not to damage to the gas supply pipe Pg (i.e., when times are different from normal), it is possible to prevent frequent alarms from being generated.

[0038] In this embodiment, the length of the predetermined period is, for example, one week or one year, but is not limited to this and can be set arbitrarily. For example, the length of the predetermined period may be changed depending on the season or the frequency of gas usage.

[0039] Furthermore, in this embodiment, a high flow rate threshold may be set. The high flow rate threshold is a threshold for determining whether or not a predetermined high flow rate of gas is present in the gas supply pipe Pg (for example, a high flow rate of gas that would flow if the gas supply pipe Pg were to break). In this case, an alarm may be issued when the maximum gas flow rate exceeds the high flow rate threshold.

[0040] (Addendum) The above description of the embodiments discloses the following techniques.

[0041] (Technology 1) A gas supply pipe is provided with a measuring unit that measures the flow rate of gas flowing through the gas supply pipe, a storage unit that stores in advance a first abnormality determination lower limit value and a first abnormality determination upper limit value that are values ​​for determining an abnormality and are compared with a maximum value of the gas flow rate in a predetermined period, and a control unit, wherein the control unit does not update the first abnormality determination lower limit value and the first abnormality determination upper limit value if the maximum value is equal to or greater than the first abnormality determination lower limit value and less than the first abnormality determination upper limit value in a first predetermined period that is the predetermined period, and if the maximum value is less than the first abnormality determination lower limit value in the first predetermined period, a judgment value update unit that updates the abnormality determination lower limit value to a second abnormality determination lower limit value that is smaller than the first abnormality determination lower limit value and smaller than the maximum value, and updates the first abnormality determination upper limit value to a second abnormality determination upper limit value that is smaller than the first abnormality determination upper limit value and larger than the maximum value, and, when the maximum value during the first predetermined period is equal to or larger than the first abnormality determination upper limit value, updates the first abnormality determination lower limit value to a third abnormality determination lower limit value that is larger than the first abnormality determination lower limit value and smaller than the maximum value, and updates the first abnormality determination upper limit value to a third abnormality determination upper limit value that is larger than the first abnormality determination upper limit value and larger than the maximum value, during the second predetermined period.

[0042] (Technology 2) The gas meter according to Technology 1, wherein the control unit ends the first predetermined period midway and starts the second predetermined period when the maximum value during the first predetermined period is equal to or greater than the first abnormality determination upper limit value.

[0043] This configuration makes it possible to quickly suppress the frequent issuance of alarms in the event of an abnormality, while quickly providing optimal safety functions according to the amount of gas used in the customer's home.

[0044] (Technology 3) The gas meter according to Technology 1 or 2, wherein the memory unit pre-stores predetermined fixed lower limit values, and the first abnormality determination lower limit value, the second abnormality determination lower limit value, and the third abnormality determination lower limit value are equal to or greater than the fixed lower limit values.

[0045] In this configuration, by using a parameter called a fixed lower limit value, it is possible to set a limit at which each abnormality determination lower limit value is not learned and updated.

[0046] (Technology 4) The gas meter according to any one of Technologies 1 to 3, further comprising a notification unit that notifies an outside party that the update has been performed.

[0047] With this configuration, a center server or the like, which is an example of the external device, can recognize from the notification that each of the abnormality determination lower limit values ​​and each of the abnormality determination upper limit values ​​has been updated. [Explanation of symbols]

[0048] 1 Gas meter 2. Breaker 3. Control Unit 4 Flow measurement section 5 Flow rate calculation section 6. Judgment value update section 7 Notification section 8 Memory section 9. External Communications Department Pg Gas supply pipe Thf fixed lower limit Th1H, Th2H, Th3H Upper limit for abnormality judgment Th1L, Th2L, Th3L Abnormality judgment lower limit

Claims

1. a measuring unit provided in the gas supply pipe and configured to measure a flow rate of gas flowing through the gas supply pipe; a storage unit that stores in advance a first abnormality determination lower limit value and a first abnormality determination upper limit value, which are values ​​for determining an abnormality and are compared with a maximum value of the gas flow rate in a predetermined period; a control unit, The control unit when the maximum value is equal to or greater than the first abnormality determination lower limit value and less than the first abnormality determination upper limit value during a first predetermined period as the predetermined period, the first abnormality determination lower limit value and the first abnormality determination upper limit value are not updated, when the maximum value in the first predetermined period is less than the first abnormality determination lower limit value, in a second predetermined period which is the predetermined period following the first predetermined period, the first abnormality determination lower limit value is updated to a second abnormality determination lower limit value which is smaller than the first abnormality determination lower limit value and smaller than the maximum value, and the first abnormality determination upper limit value is updated to a second abnormality determination upper limit value which is smaller than the first abnormality determination upper limit value and larger than the maximum value, a judgment value update unit that, when the maximum value during the first predetermined period is equal to or greater than the first abnormality judgment upper limit value, updates the first abnormality judgment lower limit value to a third abnormality judgment lower limit value that is greater than the first abnormality judgment lower limit value and less than the maximum value, and updates the first abnormality judgment upper limit value to a third abnormality judgment upper limit value that is greater than the first abnormality judgment upper limit value and greater than the maximum value, during the second predetermined period.

2. 2. The gas meter according to claim 1, wherein, when the maximum value during the first predetermined period is equal to or greater than the first abnormality determination upper limit value, the control unit ends the first predetermined period midway and starts the second predetermined period.

3. the storage unit stores a predetermined fixed lower limit value in advance, The gas meter according to claim 1 , wherein the first abnormality determination lower limit value, the second abnormality determination lower limit value, and the third abnormality determination lower limit value are equal to or greater than the fixed lower limit value.

4. The gas meter according to claim 1 , further comprising a notification unit that notifies an external device that the update has been performed.

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