Leak detection device and data storage method

Abstract

To provide a leakage detection device and a data storage method that can store data on minute leakage in an analyzable manner.SOLUTION: A gas meter 1 has a function to determine minute leakage based on pressure while use of gas is stopped, and comprises: a temporary storage unit 50 that stores an initial pressure and an initial temperature during the stop, and stores pressure and temperature acquired at a data acquisition timing for every predetermined time; and a permanent storage unit 60 that, when the number of times of acquisition of data for every predetermined time exceeds a predetermined number of times at resumption of the use of gas, converts the data stored in the temporary storage unit 50 into a predetermined format and stores a resultant data.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a leakage detection device and a data storage method.

Background Art

[0002] Conventionally, there is known a gas meter (leakage detection device) having a pressure-type minute leakage determination function that detects minute leakage of gas caused by a slight crack or the like in a pipe based on a change in gas pressure. This gas meter determines minute leakage when there has never been an increase of a predetermined pressure or more from the basic pressure when gas usage has stopped for a predetermined period (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, since gas pipes are buried underground, the gas temperature tends to be constant, and there may be no increase in the gas pressure above a predetermined pressure. Also, at night when gas usage is difficult, the gas pressure may decrease as the temperature drops. Therefore, in the gas meter as described in Patent Document 1, environments where the gas temperature is constant and environments where the temperature drops become factors for misjudgment regarding minute leakage.

[0005] Therefore, it is important to store pressure and the like so that such factors for misjudgment can be analyzed. However, in the gas meter described in Patent Document 1, only the differential pressure with respect to the basic pressure is sequentially updated and stored, and analysis cannot be performed later.

[0006] The present invention was made to solve these conventional problems, and its objective is to provide a leak detection device and a data storage method that can store data on minute leaks in an analyzable manner. [Means for solving the problem]

[0007] The leak detection device according to the present invention is a leak detection device that determines minute leaks based on pressure during a gas outage, and is characterized by comprising: a temporary storage means that stores the initial pressure and initial temperature during the outage, and stores the acquired pressure and acquired temperature acquired at predetermined time intervals; and a main storage means that, when gas outages are resumed, converts the data stored in the temporary storage means into a predetermined format and stores it if the number of data acquisitions at predetermined time intervals exceeds a predetermined number.

[0008] The data storage method according to the present invention is a data storage method for a leak detection device that determines minute leaks based on pressure during a gas outage, and is characterized by comprising: a temporary storage step that stores the initial pressure and initial temperature during the outage, and stores the acquired pressure and acquired temperature acquired at predetermined time intervals; and a main storage step that, when gas outage is resumed, converts the data stored in the temporary storage step into a predetermined format and stores it if the number of data acquisitions at predetermined time intervals exceeds a predetermined number. [Effects of the Invention]

[0009] According to the present invention, data can be stored in an analyzable manner regarding minute leaks. [Brief explanation of the drawing]

[0010] [Figure 1] This is a block diagram showing the configuration of a leak detection device according to an embodiment of the present invention. [Figure 2] Figure 1 is a conceptual diagram showing the contents of the temporary memory unit. [Figure 3] Figure 1 is a conceptual diagram showing the memory state of this memory unit. [Figure 4] This is a flowchart illustrating a data storage method according to the first embodiment, showing the first half of the process. [Figure 5] This is a flowchart illustrating a data storage method according to the first embodiment, showing the latter half of the process. [Figure 6] This is a data storage method according to the second embodiment. [Modes for carrying out the invention]

[0011] The present invention will be described below in accordance with preferred embodiments. It should be noted that the present invention is not limited to the embodiments shown below, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, in the embodiments shown below, some illustrations and descriptions of certain components are omitted. It goes without saying that, regarding the details of the omitted technologies, publicly known or well-known technologies are applied as appropriate, to the extent that they do not contradict the content described below.

[0012] Figure 1 is a block diagram showing the configuration of a gas meter according to an embodiment of the present invention. The gas meter (leak detection device) 1 shown in Figure 1 measures and displays the flow rate of fuel gas supplied to the consumer side, and performs various safety functions by closing a shut-off valve (not shown). In the first embodiment, the gas meter 1 is given as an example of a leak detection device, but it is not limited to the gas meter 1 and may be applied to leak detection devices installed on bypass flow paths in LP gas supply facilities.

[0013] As shown in Figure 1, the gas meter 1 includes a flow rate measuring unit 10, a pressure sensor 20, a temperature sensor 30, a control unit 40, a temporary storage unit (temporary storage means) 50, a main storage unit (main storage means) 60, and a communication unit 70.

[0014] The flow rate measurement unit 10 measures the flow rate of fuel gas flowing through a flow path (not shown) formed inside the gas meter 1, and is composed of a flow rate sensor (not shown), a calculation unit (not shown), and the like. The flow rate information measured by the flow rate measurement unit 10 is transmitted to the control unit 40. The pressure sensor 20 detects the gas pressure in the flow path. The gas pressure signal detected by the pressure sensor 20 is transmitted to the control unit 40. The temperature sensor 30 detects the temperature in the environment in which the gas meter 1 is installed. The temperature signal detected by the temperature sensor 30 is transmitted to the control unit 40.

[0015] The control unit 40 controls the entire gas meter 1. This control unit 40 has a function to display the cumulative flow rate measured by the flow rate measurement unit 10, for example. The control unit 40 also includes a small leak detection unit 41, a memory control unit 42, and a communication control unit 43.

[0016] The minute leak detection unit 41 is a pressure-type minute leak detection unit that detects minute gas leaks caused by small cracks in piping, etc., based on changes in gas pressure. This minute leak detection unit 41 determines minute leaks based on the pressure change from the initial pressure P0 when gas use is stopped on the consumer side. Specifically, the minute leak detection unit 41 reads the signal from the pressure sensor 20 at data acquisition timings every predetermined time (e.g., every 15 minutes), and if the pressure Pn at this time (acquired pressure: n is a positive integer and indicates the number of acquisitions) is higher than the initial pressure P0 by a predetermined value (e.g., 0.2 kPa) or more, it determines that there is no minute leak. On the other hand, if the pressure Pn never exceeds the initial pressure P0 + predetermined value over a predetermined period (e.g., 30 days), it determines that there is a minute leak. In addition to pressure-type minute leak detection, the minute leak detection unit 41 may also perform flow-type minute leak detection.

[0017] The memory control unit 42 executes processes related to the memories of the temporary memory unit 50 and the main memory unit 60. The temporary memory unit 50 temporarily stores the data acquired when the minute leakage determination unit 41 makes a minute leakage determination. The main memory unit 60 stores the data stored in the temporary memory unit 50 when a predetermined condition is satisfied. Hereinafter, the stored contents of each of the memory units 50 and 60 and the memory process by the memory control unit 42 will be described.

[0018] FIG. 2 is a conceptual diagram showing the stored contents of the temporary memory unit 50 shown in FIG. 1. The memory control unit 42 stores various information in the temporary memory unit 50 when the use of the gas stops and the flowmeter 10 measures no flow. As shown in FIG. 2, the temporary memory unit 50 has storage areas A1 and A2 for the initial pressure P0, which is the gas pressure at the time when no flow is measured, and the initial temperature D0, which is the temperature at the time when the initial pressure P0 is obtained. Further, the temporary memory unit 50 has storage areas A3 to A5 for the pressure Pn and the temperature (acquisition temperature) Dn acquired at a predetermined acquisition timing, and the acquisition count n indicating the number of acquisitions of the pressure Pn and the temperature Dn. In addition, the temporary memory unit 50 has storage areas A6 to A8 for the initial pressure decrease flag, the pressure abnormal increase flag, and the measurement date and time. The memory control unit 42 performs storage, update, etc. to each of the storage areas A1 to A8 of the temporary memory unit 50 as described above.

[0019] Specifically, when no flow is measured, the memory control unit 42 first stores the initial pressure P0 and the initial temperature D0 in the first and second storage areas A1 and A2 of the temporary memory unit 50 based on the signals from the pressure sensor 20 and the temperature sensor 30. Also, the memory control unit 42 stores the measurement date and time at this time in the eighth storage area A8. Thereafter, every time a predetermined acquisition timing arrives, the memory control unit 42 increments the acquisition count n in the third storage area A3, and overwrites and updates the contents of the other storage areas A1, A2, A4 to A7 of the temporary memory unit 50 when a predetermined condition (any of the following three conditions) is satisfied.

[0020] The first condition is when the currently acquired pressure Pn exceeds the past pressure Pk (where k is an integer from 0 or more and less than n). In this case, the memory control unit 42 overwrites and updates the past pressure Pk stored in the fourth memory area A4 with the current pressure Pn. Also, the memory control unit 42 overwrites and updates the current temperature Dn at the time when the current pressure Pn is overwritten and updated in the fifth memory area A5.

[0021] The second condition is when the currently acquired pressure Pn is lower than the initial pressure P0. In this case, the memory control unit 42 overwrites and updates the initial pressure P0 stored in the first memory area A1 with the current pressure Pn. That is, the current pressure Pn becomes the initial pressure P0. Also, when the current pressure Pn is overwritten and updated, the initial temperature D0 stored in the second memory area A2 is also overwritten and updated with the current temperature Dn. In addition, the memory control unit 42 turns on the initial pressure decrease flag in the sixth memory area A6.

[0022] The third condition is when the currently acquired pressure Pn rises by more than a specified value (for example, 0.2 kPa) compared to the previous pressure Pn-1. In this case, it can be said that there has been an abnormal pressure rise. At this time, the memory control unit 42 overwrites and updates the initial pressure P0 stored in the first memory area A1 with the current pressure Pn. That is, the current pressure Pn becomes the initial pressure P0. Also, when the current pressure Pn is overwritten and updated, the initial temperature D0 stored in the second memory area A2 is also overwritten and updated with the current temperature Dn. In addition, the memory control unit 42 turns on the pressure abnormal rise flag in the seventh memory area A7.

[0023] By repeating the above-described overwriting and updating, the memory control unit 42 stores one piece of data in each of the first to eighth memory areas A1 to A8 of the temporary memory unit 50. Such a combination of one piece of data is called a data set.

[0024] In addition, the memory control unit 42 also performs storage processing to the main storage unit 60. Here, when the flow rate measurement unit 10 changes from a state where no flow rate is measured to a state where a flow rate is measured, and the number of acquisitions n stored in the third storage area A3 of the temporary storage unit 50 exceeds a predetermined number (for example, 12 times), the memory control unit 42 stores the dataset from the temporary storage unit 50 in the main storage unit 60. When storing the dataset from the temporary storage unit 50 in the main storage unit 60, the memory control unit 42 converts the information of the dataset into a predetermined format before storing it. At this time, the memory control unit 42 may, for example, convert the information of the dataset from the temporary storage unit 50 into a data format managed by a predetermined organization such as a gas management center. Also, if it is intended to output data to a predetermined organization, the data format for communication output may be converted. When converting and storing the data in the main storage unit 60, some information may be deleted or added, or data compression may be performed.

[0025] The communication control unit 43 is a control unit for transmitting the contents of the storage unit 60 to a predetermined institution. Figure 3 is a conceptual diagram showing the storage state of the storage unit 60 shown in Figure 1. The storage unit 60 can store m (m is an integer of 2 or more) pieces of data (converted) from the temporary storage unit 50. When the number of data sets stored in the storage unit 60 reaches m, the communication control unit 43 transmits the m data sets to a predetermined institution via the communication unit 70. After transmission to the predetermined institution, the storage control unit 42 is expected to delete the m data sets, but it may also perform processing such as leaving the most recent few without deleting them. Furthermore, when transmitting data sets to a predetermined institution, it is not necessary to transmit all m data sets; only the oldest few may be transmitted, and only the transmitted data sets may be deleted.

[0026] As described above, the memory control unit 42 stores the data set in the main memory unit 60 when the number of acquisitions n in the third memory area A3 exceeds a predetermined number. Therefore, data sets that have been acquired infrequently and are unlikely to be significant in subsequent analysis are not stored in the main memory unit 60. This allows for the storage of data that is significant in the analysis of minute leaks.

[0027] Next, the data storage method according to the first embodiment will be described. Figures 4 and 5 are flowcharts of the data storage method according to the first embodiment. As shown in Figure 4, first the control unit 40 determines whether there is no flow rate based on the information from the flow rate measurement unit 10 (S1). If there is no flow rate (S1: NO), this process is repeated until it is determined that there is no flow rate.

[0028] If there is no flow rate (S1:YES), the memory control unit 42 acquires information on the initial pressure P0 and initial temperature D0 based on signals from the pressure sensor 20 and temperature sensor 30, and temporarily stores it in the first and second memory areas A1 and A2 (S2). At this time, the memory control unit 42 also temporarily stores the measurement date and time in the eighth memory area A8.

[0029] Subsequently, the control unit 40 determines whether a predetermined acquisition timing has arrived (S3). If the predetermined acquisition timing has not arrived (S3:NO), the process proceeds to step S11. If the predetermined acquisition timing has arrived (S3:YES), the memory control unit 42 acquires pressure Pn and temperature Dn information based on signals from the pressure sensor 20 and temperature sensor 30, and increments the acquisition count n in the third memory area A3 (S4).

[0030] Next, the memory control unit 42 determines whether the pressure Pn acquired in step S4 exceeds the past pressure Pk (S5). That is, the memory control unit 42 determines whether the above first condition is met. If the pressure Pn does not exceed the past pressure Pk (S5: NO), the process proceeds to step S7. If the pressure Pn exceeds the past pressure Pk (S5: YES), the memory control unit 42 updates and stores the pressure Pn and temperature Dn acquired in step S4 in the fourth and fifth memory areas A4 and A5 (S6). After that, the process proceeds to step S7.

[0031] In step S7, the memory control unit 42 determines whether the pressure Pn obtained in step S4 is lower than the initial pressure P0 (S7). That is, the memory control unit 42 determines whether the second condition above is met. If the pressure Pn is not lower than the initial pressure P0 (S7: NO), the process proceeds to step S9. If the pressure Pn is lower than the initial pressure P0 (S7: YES), the memory control unit 42 turns on the initial pressure decrease flag in the sixth memory area A6 and updates the pressure Pn and temperature Dn obtained in step S4 in the first and second memory areas A1 and A2 (S8). That is, the initial pressure P0 and initial temperature D0 are updated. After that, the process proceeds to step S9.

[0032] In step S9, the memory control unit 42 determines whether the pressure Pn acquired in step S4 has risen by more than a specified value compared to the previous pressure Pn-1 (S9). That is, the memory control unit 42 determines whether the above third condition is met. If the pressure Pn has not risen by more than a specified value compared to the previous pressure Pn-1 (S9: NO), the process proceeds to step S11. If the pressure Pn has risen by more than a specified value compared to the previous pressure Pn-1 (S9: YES), the memory control unit 42 turns on the pressure abnormal rise flag in the seventh memory area A7 and updates the pressure Pn and temperature Dn acquired in step S4 in the first and second memory areas A1 and A2 (S10). That is, the initial pressure P0 and initial temperature D0 are updated. After that, the process proceeds to step S11.

[0033] In step S11, the control unit 40 determines whether there is flow based on the information from the flow measurement unit 10 (S11). If there is no flow (S11: NO), the process proceeds to step S3. On the other hand, if there is flow (S11: YES), the control unit 40 determines whether the number of acquisitions n stored in the third memory area A3 exceeds a predetermined number (Figure 5: S12).

[0034] If the number of acquisitions n does not exceed a predetermined number (S12: NO), the memory control unit 42 discards the data stored in the temporary storage unit 50 (S13). After that, the processes shown in Figures 4 and 5 are completed. On the other hand, if the number of acquisitions n exceeds a predetermined number (S12: YES), the memory control unit 42 converts the data set stored in the temporary storage unit 50 into a predetermined format (S14) and stores it in the main storage unit 60 (S15). After that, the memory control unit 42 erases the data stored in the temporary storage unit 50 (S16).

[0035] Next, the communication control unit 43 determines whether the number of datasets stored in the storage unit 60 has reached its maximum (S17). If the number of datasets has not reached its maximum (S17: NO), the process shown in Figures 4 and 5 ends. On the other hand, if the number of datasets has reached its maximum (S17: YES), the communication control unit 43 transmits the multiple datasets stored in the storage unit 60 to a designated institution or the like (S18). Next, the storage control unit 42 erases the data stored in the storage unit 60 (S19). After that, the process shown in Figures 4 and 5 ends.

[0036] In this way, according to the gas meter 1 and data storage method of the first embodiment, initial pressure P0, initial temperature D0, pressure Pn, temperature Dn, etc. are stored in the temporary storage unit 50 when gas use is stopped, and when gas use is restarted and the number of data acquisitions n exceeds a predetermined number, the data stored in the temporary storage unit 50 is converted to a predetermined format and stored in the main storage unit 60. Therefore, data that is significant during analysis can be stored in the main storage unit 60 when the number of acquisitions n is sufficiently large. In addition, since the data is converted to a predetermined format during main storage, it can be stored in an appropriate format when analysis is performed by an external device, etc. Thus, data can be stored in a way that allows for analysis of minute leaks.

[0037] Furthermore, since the contents of the temporary storage unit 50 are updated when predetermined conditions are met, it is possible to store data necessary for analysis in the form of updates without overwhelming the data capacity.

[0038] Next, a second embodiment of the present invention will be described. The gas meter 1 and data storage method according to the second embodiment are the same as those of the first embodiment, but some processing details differ. The differences from the first embodiment will be explained below.

[0039] In the first embodiment, the gas meter 1 had a memory control unit 42 that determined whether the first to third conditions were met, and if so, it overwrote and updated the data (pressure Pn, etc.) stored in the temporary storage unit 50. In contrast, the gas meter 1 in the second embodiment sequentially stores pressure Pn and temperature Dn in the temporary storage unit 50 without overwriting each time a predetermined acquisition timing arrives. Then, when it is determined that there is flow, the initial pressure P0 and initial temperature D0, as well as the pressure Pn and temperature Dn that have been sequentially stored without overwriting, are selected one by one according to the specified conditions to form a single data set. After that, the gas meter 1 in the second embodiment, similar to the first embodiment, converts the single data set and stores it in the main storage unit 60. A detailed explanation follows below.

[0040] Figure 6 is a flowchart showing the data storage method according to the second embodiment. As shown in Figure 6, first the control unit 40 executes the processes in steps S21 to S23. These processes are the same as the processes in steps S1 to S3 shown in Figure 4.

[0041] When the predetermined acquisition timing arrives (S23:YES), the memory control unit 42 acquires pressure Pn and temperature Dn information and temporarily stores it in the temporary storage unit 50, and also increments the acquisition count n in the third storage area A3 (S24). In this case, unlike the first embodiment, the data is not overwritten and updated, and is accumulated. Subsequently, the control unit 40 determines whether there is flow based on the information from the flow measurement unit 10 (S25). If there is no flow (S25:NO), the process proceeds to step S23. On the other hand, if there is flow (S25:YES), the control unit 40 determines whether the acquisition count n stored in the third storage area A3 for the latest data exceeds a predetermined number (S26).

[0042] If the number of acquisitions n does not exceed a predetermined number (S26: NO), the memory control unit 42 discards the data stored in the temporary storage unit 50, similar to step S13 shown in Figure 5 (S27). After that, the process shown in Figure 6 ends. On the other hand, if the number of acquisitions n exceeds a predetermined number (S26: YES), the memory control unit 42 selects the data to be stored in the temporary storage unit 50 to form a single data set based on the specified conditions (S28).

[0043] The specified conditions are the same as the first to third conditions described above. Therefore, the memory control unit 42 first performs the same processing as steps S5 to S10 shown in Figure 4 based on the data with an acquisition count of n=1, and then sequentially performs the same processing as steps S5 to S10 for acquisition counts n=2 and beyond. After performing the processing of steps S5 to S10 for all the data sequentially stored in the temporary storage unit 50, one data set will remain. In this way, the memory control unit 42 performs the process of selecting one data set by repeatedly executing the processing of steps S5 to S10 shown in Figure 4 to leave one data set.

[0044] Subsequently, in steps S29 to S34, the same process as in steps S14 to S19 shown in Figure 5 is executed. Then, the process shown in Figure 6 is completed.

[0045] In this way, according to the gas meter 1 and data storage method of the second embodiment, data can be stored in a way that allows for analysis of minute leaks.

[0046] Furthermore, according to the second embodiment, when gas use is resumed, the data stored sequentially in the temporary storage unit 50 is selected one by one according to specified conditions without being overwritten, converted to a predetermined format, and then stored. As a result, the main storage unit 60 stores data that is significant for analysis according to the specified conditions, and the data can be stored without putting a strain on the data capacity of the main storage unit 60.

[0047] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments, and modifications may be made, other technologies may be combined as appropriate to the extent possible, or technologies from different embodiments may be combined, without departing from the spirit of the present invention.

[0048] For example, although a gas meter 1 was used as an example in this embodiment, the device may also be applied to a leak detection device that does not have a measuring function like the gas meter 1, but simply detects minute leaks.

[0049] Furthermore, in the above embodiment, it is assumed that the multiple data sets stored in the storage unit 60 will be transmitted to a predetermined organization via a public network such as an internet line, but the invention is not limited to this, and may also be transmitted to terminals held by gas-related workers, etc., via narrow-range wireless communication, etc.

[0050] Furthermore, in the above embodiment, the temporary storage unit 50 stores the number of acquisitions in the third storage area A3, but it is not necessary to store the number of acquisitions. For example, if pressure Pn and temperature Dn information is acquired every 15 minutes, the number of acquisitions will become clear based on the time it takes for the flow rate to change from no flow rate to flow rate.

[0051] Furthermore, in the above embodiment, the temporary storage unit 50 stores an initial pressure decrease flag, a pressure abnormal increase flag, and the measurement date and time in the sixth to eighth storage areas A6 to A8, but these do not need to be stored. This is because they are not essential for the analysis of minute leaks. In other words, since analysis is possible with only the information of the initial pressure P0, initial temperature D0, pressure Pn, and temperature Dn, the temporary storage unit 50 may store only this information, and the dataset may consist only of this information. [Explanation of Symbols]

[0052] 1: Gas meter (leak detection device) 10: Flow rate measurement unit 20: Pressure sensor 30: Temperature sensor 42: Memory Control Unit 50: Temporary memory unit (temporary memory means) 60: Main memory unit (main memory means) A1~A8: Memory Area D0 :Initial temperature Dn: Temperature (obtained temperature) P0: Initial pressure Pn: Pressure (Acquired pressure)

Claims

1. In a leak detection device that determines minute leaks based on pressure during a gas outage, A temporary storage means that stores the initial pressure and initial temperature during the aforementioned stop, and also stores the acquired pressure and acquired temperature acquired at predetermined time intervals. When gas use is resumed, if the number of data acquisitions at predetermined intervals exceeds a predetermined number, the main storage means converts the data stored in the temporary storage means into a predetermined format and stores it, A leak detection device characterized by comprising the following:

2. The temporary storage means updates at least one of the initial pressure, initial temperature, acquired pressure, and acquired temperature when a predetermined condition is met at the data acquisition timing at predetermined time intervals, thereby storing one dataset of the initial pressure, initial temperature, acquired pressure, and acquired temperature during the shutdown period. The leak detection device according to feature 1.

3. The temporary storage means stores the initial pressure and initial temperature during the stop, and sequentially stores the acquired pressure and acquired temperature acquired at the predetermined time intervals for data acquisition. The storage means selects one of each of the initial pressure and initial temperature data stored in the temporary storage means, as well as the sequentially stored acquired pressure and acquired temperature data, according to specified conditions, converts them to a predetermined format, and stores them. The leak detection device according to feature 1.

4. In a data storage method for a leak detection device that determines minute leaks based on pressure during a gas outage, A temporary storage step that stores the initial pressure and initial temperature during the aforementioned stoppage, and also stores the acquired pressure and acquired temperature acquired at predetermined time intervals. When gas use is resumed, if the number of data acquisitions at predetermined intervals exceeds a predetermined number, the main storage step converts the data stored in the temporary storage step into a predetermined format and stores it, A data storage method for a leak detection device, characterized by comprising the following:

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