JP4845822B2 - Flow rate measuring device and fluid supply system - Google Patents

Description

  The present invention relates to a technique for correctly discriminating an instrument that uses a fluid by capturing a change in the flow rate of the fluid.

  Conventionally, there exists a thing of patent documents 1 as a gas meter device which specifies a use instrument in a fluid piping system which has a gas meter device. As shown in FIG. 9, the gas meter device 1 of this document is disposed in a flow path 6 connected to a household gas supply pipe, and a flow rate measuring unit 3 and a flow rate measuring unit 3 that measure a gas flow rate at regular time intervals. Calculating means 4 for obtaining the difference value of the flow rate value output from the difference between the difference value calculated by the calculating means 4 and the change determination value registered in the storage means 5, It is the structure which has the comparison determination means 7 which determines a change. The calculation means 4, the comparison determination means 7, and the gas cutoff valve 2 are controlled by a control circuit 8.

In the gas meter device 1, the change in the difference value of the instantaneous flow rate output from the flow rate measuring means 3 is sequentially calculated, and the change in the usage state of the gas appliance is determined by the change amount. And the change (difference value) in the measured gas flow rate are compared, and the used gas appliances 13, 14, and 15 can be discriminated.
JP-A-2006-313114

  In the above configuration, since the difference value is used as it is, it is basically local on the time axis, so it is difficult to say that the accuracy of instrument discrimination is sufficient, and the flow rate measured over a long time When trying to make an overall determination based on the value, it takes time to determine the gas appliance, and the amount of memory required becomes enormous.

  The present invention has been made in order to solve the above-described problems, and its purpose is to improve calculation speed and instrument discrimination accuracy while reducing the amount of memory required for calculation by simplifying calculation. It is in.

  The flow rate measuring device of the present invention includes a flow rate measuring unit that measures the flow rate of the fluid flowing in the flow path at regular time intervals, and an arithmetic unit that computes a difference value of the flow rate measured by the flow rate measuring unit at regular intervals. A plurality of difference value categories according to the magnitude of the difference value, a flow rate classification table associated with a code representing each category, and a difference value calculated by the calculation unit based on the flow rate classification table A difference value conversion unit for converting to the code, a code sequence generation unit for generating a measurement code sequence based on the set of codes for each predetermined time obtained by the difference value conversion unit, and the measurement code sequence are repeatedly generated. An appliance discriminating unit that discriminates an appliance that uses the fluid based on the pattern.

  According to the present invention, a sign value obtained by encoding (converting) a difference value of the flow rate is used when determining the fluid use device. Further, it is possible to more accurately discriminate the appliance based on the pattern repeatedly generated in the calculated measurement code string. Accordingly, when performing the instrument discrimination, the calculation is simplified, and it is possible to improve the calculation speed and the instrument discrimination accuracy while reducing the amount of memory necessary for the calculation.

  In the flow rate measuring apparatus of the present invention, the measurement code string may be used when the instrument is operating, for example, a rising characteristic of the flow rate including the start of use of the fluid by the instrument, a falling characteristic of the flow rate including the end of use of the fluid, or the fluid This shows the control characteristics of the flow rate during stable use. By picking up the characteristic characteristic for each device as a code string, it is possible to accurately determine the device.

  In the flow rate measuring device of the present invention, the pattern in the measurement code string includes a pattern that is periodically repeated. Further, the instrument discriminating unit discriminates an instrument based on a pattern repeatedly generated in the measurement code string and an appearance interval of the pattern, or a pattern periodically repeated in the measurement code string and the pattern And a device for discriminating an appliance based on the period of the above. In addition, the cycle of the pattern is the length from the start of use to the next start of use, the length from the end of use to the end of the next use, The length from the end of use to the next start of use is included. Instrument discrimination can be performed more accurately by the patterns in these measurement code strings.

  Furthermore, according to the present invention, a flow rate measuring method executed by the flow rate measuring device and a computer program for controlling the flow rate measuring device are provided. Furthermore, a fluid supply system using these apparatuses, methods, and programs is provided.

  According to the present invention, it is possible to improve the calculation speed and the accuracy of appliance discrimination while reducing the amount of memory required for appliance discrimination.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a block diagram of a gas meter as a flow rate measuring apparatus in an embodiment of the present invention.

  In FIG. 1, the gas meter 100 includes a flow path 102, an ultrasonic flowmeter 104 as a flow rate measurement unit, a measured flow rate information storage unit 106, a calculation unit 108, a flow rate classification table holding unit 110, and a difference value conversion unit 112. A code string generation unit 114, a device determination unit 116, and a device-specific code string information holding unit 118. Furthermore, the gas meter 100 includes a flow path cutoff valve 122 that is disposed in the flow path 102 and shuts off the gas in an emergency or the like.

  The ultrasonic flowmeter 104 measures the flow rate by emitting ultrasonic waves at a constant time interval (for example, 2 seconds) with respect to the gas as the fluid flowing in the flow path 102, and uses a general one. can do. The measured flow rate information storage unit 106 stores the measured flow value measured by the ultrasonic flow meter 104 and target data described in association with the measurement time when the measured flow rate value was measured.

  The calculation unit 108 calculates a difference value for each fixed time corresponding to the above-described ultrasonic wave emission interval of the gas flow rate measured by the ultrasonic flowmeter 104. For example, in FIG. 3 described later, when the flow rate (absolute flow rate) at a predetermined timing is 60 L / h (liters per hour) and the flow rate at the next timing is 120 L / h, the difference value at this time is 120-60 = It is calculated as 60 (L / h). Here, the calculation of the difference value may be performed at the flow rate at the next next timing (the flow rate next to the flow rate of 120 L / h).

  As shown in FIG. 2, the flow rate classification table holding unit 110 holds a flow rate classification table 110a in which a plurality of difference value categories according to the size of the difference values and codes representing each category are associated. is there. The flow rate classification table 110a functions as a conversion table that classifies the measured difference values into predetermined categories and converts them into predetermined codes representing the categories. The number of sections in the flow rate classification table 110a is not particularly limited, but two types of 16 (code N1) and 4 (code N2) are prepared in FIG. That is, the gas meter 100 can be used by appropriately switching between a flow rate classification table with 16 divisions and a flow classification table with 4 divisions.

  As shown in FIG. 2, in the flow rate classification table, two types of classification represented by code N1 and code N2 are prepared. In the code N1, the classification of the flow rate classification table is an area where the flow rate is determined to be zero, an area where the flow rate is determined to be stable (stable area), an area where the flow rate is determined to increase (increase area), and the flow rate. Is divided into four events in a region (decreased region) in which it is determined that the number is decreasing. As shown in the table, these four areas are associated with four numbers of 0, 1, 2, and 3, and can be represented by 2-bit codes. That is, 0 can be expressed as “00”, 1 as “01”, 2 as “10”, and 3 as “11”. In this way, by expressing the classification using a code instead of a conventional difference value, better affinity with the microcomputer program is ensured, and a determination index can be provided with a small memory size and a small amount of calculation.

  In this example, the region in which the flow rate is determined to be zero has been described. However, in an actual apparatus, the actually measured flow rate has a slight variation, and thus it is not often zero. Therefore, the flow rate becomes zero, including when the flow rate is substantially zero and substantially zero.

  The code N2 is generated by further subdividing each of the above-mentioned areas. The stable area is divided into seven according to the degree of flow stability, four according to the degree of increase, and four according to the degree of decrease in the flow. Each is generated by subdividing. The area where the flow rate is judged as zero is not subdivided. Therefore, the code N2 can be expressed by a 4-bit code (0 to 9, A to F).

  In the code N1, each region is subdivided with different flow rate intervals. For example, in the increase region, the smaller the difference flow rate, the smaller the interval. For example, in the area of the code “6”, the width of the differential flow rate is 150−100 = 50 L / h, but in the area of the code “4”, 50−10 = 40 L / h, and in the area of the code 3 is 10−1. = 9 L / h. Such a configuration is adopted because it is necessary to reduce the interval in order to increase the discrimination accuracy because there are many types of instruments in the region where the differential flow rate is small.

  The difference value conversion unit 112 converts the difference value calculated by the calculation unit 108 into a code representing a category into which the difference value for each predetermined time (ultrasonic emission) is classified based on the flow rate classification table 110a. The code string generation unit 114 generates a measurement code string, which is a code string obtained by actual measurement, based on a set of codes at regular intervals obtained by the difference value conversion unit 112. This measurement code string represents a change in the flow rate of the fluid in a pseudo manner. The code generation unit 114 records the generated measurement code string in a memory (not shown) as necessary.

  The appliance discriminating unit 116 discriminates a gas appliance that uses a gas as a fluid based on the measurement code string generated by the code string generating unit 114. Here, the appliance discriminating unit 116 compares the measurement code sequence with an appliance specific code sequence indicating a code sequence specific to the gas appliance stored in advance in the appliance specific code sequence information holding unit 118 for each gas appliance, and the similarity relationship between them. The gas appliance that uses gas is determined from the above.

  The appliance-specific flow rate calculation unit 120 can also calculate the flow rate for each gas appliance determined by the appliance determination unit 116. Further, the gas meter 100 is connected to the gas pipe line 19 on the upstream side, and connected to various gas appliances 13, 14, 15 such as a gas table, a fan heater, and floor heating on the downstream side.

Hereinafter, a flow rate change history recording method using the gas meter 100 of the present embodiment will be described. First, the flow rate (absolute flow rate) Q (n) measured at a predetermined time interval (for example, 2 seconds) by the ultrasonic flow meter 104 and the flow rate Q (n−1) measured last time are stored in the measured flow rate information storage. The information is temporarily stored in the unit 106. Thereafter, the calculation unit 108 calculates a difference value ΔQ (n) = Q (n) −Q (n−1) that is a difference between Q (n) and the flow rate Q (n−1) measured last time.
Here, the fixed interval may be 4 seconds or 6 seconds.

  The difference value conversion unit 112 is a code that represents the difference value ΔQ (n) calculated by the calculation unit 108 with reference to the flow rate classification table 110a of FIG. It is converted into a code (2-bit code or 4-bit code of N1 or N2). Here, it is possible to freely select which of the division codes N1 and N2 is used.

  FIG. 3 shows an example of conversion using such a flow rate classification table. When a gas appliance A (for example, a fan heater) corresponding to any of the gas appliances 13, 14, and 15 in FIG. 1 starts to start and a gas flow rate is generated, the measured flow rate is “flow rate” in FIG. Value ”, as shown in the graph of FIG. 3B, the flow rate Q (n) = 0 to the flow rate Q (n) ≠ 0, and the flow rate changes according to the amount of gas used. Simultaneously with the measurement of the flow rate by the ultrasonic flowmeter 104, the calculation unit 108 calculates the difference value, and the difference value conversion unit 112 performs conversion into the category code N1 or the category code N2.

  From the code obtained as a result of the conversion, the code string generation unit 114 generates a measurement code string corresponding to the 2-bit code or 4-bit code of “partition code N1” and “partition code N2” in FIG. . The measurement code string obtained by actual measurement, which is a set of codes at regular intervals, is a pseudo representation of a change in gas flow rate, and the code string generation unit 114 obtains the obtained measurement code. Records columns in a memory (not shown) as necessary.

  That is, “classification code N1” and “classification code N2” in FIG. 3A do not represent the flow rate itself as in the “flow rate value” in FIG. 3A and the graph in FIG. Absent. However, such a code string generally changes the gas flow rate, that is, the region where the flow rate is determined to be zero, the region where the flow rate is determined to be stable, the region where the flow rate is determined to increase, and the flow rate decreases. The four events of the area judged to be in a pseudo manner are represented in a pseudo manner, and the change in the behavior of the approximate flow rate can be grasped using the code string.

  The measurement code string described above is very easy to handle because the memory size is small although the amount of information is reduced compared to the history of difference values of the prior art. Accordingly, various arithmetic processes by a device such as a gas meter can be facilitated, and the required memory amount provided in the device or at other locations can be reduced. In addition, the measurement code string of the present invention has a smaller memory size even if it is data for the same measurement time as compared to a history made up of difference values of the prior art, so it can handle data with a longer measurement time. It becomes easy.

  In addition, when such a measurement code string is unique to each gas appliance, it is possible to determine the gas appliance using the gas.

  Attention is paid to the flow rate change from the start of gas use to a predetermined time, for example, until the third sampling (6 seconds have elapsed). In the example of the gas appliance A in FIG. 3, the classification code N1 (measurement code string) is “0553”. On the other hand, the gas flow rate classification code N1 (measurement code string) until the third sampling is obtained by the gas flow rate after starting the gas appliance B (for example, a water heater) shown in FIG. 0777 ".

  Here, when the codes N1 of the gas appliance A and the gas appliance B are compared, the gas appliance A rises along a unique code string “0553”, and the gas appliance B rises along a unique code string “0777”. A unique code string that is an individual rising characteristic for each gas appliance is stored in advance, and if the classification code N1 that is a measurement code string obtained by measurement and conversion is “0553”, the gas used. It can be determined that the appliance is the gas appliance A. Further, if the classification code N1 that is the obtained measurement code string is “0777”, it can be determined that the used gas appliance is the gas appliance B.

  The appliance discriminating unit 116 discriminates a gas appliance that uses gas by the above-described method based on the measurement code string generated by the code string generating unit 114. Here, the appliance discriminating unit 116 compares the measurement code string with the unique code string unique to the gas appliance stored in the appliance-specific code string information holding unit 118 for each gas appliance in advance, and uses the gas based on the similarity or the like. Identify the gas appliance to be used. Similar to N1 and N2 in FIGS. 3 and 4, a code string specific to the gas appliance is stored in advance in the instrument specific code string information holding unit 118. The code string unique to the gas appliance is created in consideration of the codes N1 and N2 corresponding to the differential flow zones in the flow rate classification table 110a shown in FIG.

  In the above-described example, the measurement code string and the instrument specific code string indicate the rising characteristics of the gas instrument A, the gas instrument B,..., That is, the rising characteristics of the flow rate immediately after the start of gas use by the gas instrument. It is. However, there is no particular limitation as long as the gas appliance can be specified, and the measurement code string and the instrument specific code string generally indicate control characteristics (control characteristics of the flow rate) during operation of the gas instrument. Used. The flow rate characteristics during operation of the device include, for example, a flow rate rising characteristic immediately after the start of use of the fluid by the device, a flow rate falling characteristic at the end of use of the fluid, or a flow rate control characteristic during stable use of the fluid. included. Here, the code sequence unique to the gas appliance stored in the appliance specific code sequence information holding unit 118 may be learned and corrected by actual flow measurement instead of being set in advance.

  Further, when attention is paid to the code N2 from the rise (starting time) of the flow rate to a predetermined time (for example, the seventh), the code N2 of the gas appliance A is “01131133” and the code N2 of the gas appliance B is “01111333”. ing. Here, the code N2 is defined as 0: an area where the flow rate is zero, 1: an increasing area, 2: a decreasing area, 3: a stable area, and the gas appliance A rises once and increases temporarily. It is understood from the code N2 of the gas appliance A that there is a characteristic that increases again. On the other hand, it can be understood from the code N2 of the gas appliance B that the gas appliance B has a characteristic that it once rises, continues to increase, and then stabilizes. Therefore, if the code N2 is “01131133”, it is possible to determine the possibility that the gas appliance used is the gas appliance A. If the code N2 is “01111333”, it is possible to determine the possibility that the gas appliance used is the gas appliance B. And the characteristic of the gas appliance A and the characteristic of the gas appliance B can be easily determined by combining the code N1 and the code N2.

  In FIG. 3 and FIG. 4, the rising characteristics of the flow rate immediately after the start of gas use are compared between the two gas appliances, and the gas appliances are discriminated. FIG. 5 shows an example of discriminating a gas appliance by comparing flow rate change characteristics during operation of the gas appliance. FIGS. 5A and 5B show a table and a graph of flow rate changes including the timing at which the used flow rate increases during operation of the gas appliance C, and FIGS. 5C and 5D show the gas flow. The table | surface and graph of the flow volume change during operation | movement after the gas use start of the instrument D are shown.

  When the amount of gas used by the gas appliance C increases, in the operation example of FIGS. 5A and 5B, the flow rate increases at the 11th measured flow rate, and is stable again after the 13th. The increase characteristic during operation is represented by “333333333333113...” In the code string of the code N2 and “9991111199991449...” In the code string of the code N1. In each code string, the increased area corresponds to the “11” portion in the code N2 and the “44” portion in the code N1. Therefore, when the code N2 of the flow rate increase characteristic during operation is “11” or the code N1 is “44”, it can be determined that the gas appliance C is the gas appliance C to be used.

  Further, in the operation example of the gas appliance D in FIGS. 5C and 5D, the flow rate increases at the 10th measured flow rate, and is stable again after the 13th. The increase characteristic during operation is represented by “011133331113...” In the code string of the code N2 and “05653AA 234542...” In the code string of the code N1. In each code string, the increased area corresponds to the “111” portion in the latter half of the code N2 and the “454” portion in the code N1. Therefore, when the code N2 of the flow rate increase characteristic during operation is “111” or the code N1 is “454”, it can be determined that the gas appliance D is the gas appliance D to be used.

  The flow rate increase characteristic of the gas appliance C is represented by a two-digit continuous code, whereas the flow rate increase characteristic of the gas appliance D is represented by a three-digit continuous code. This means that the gas appliance C exhibits a rapid increase characteristic and the gas appliance D exhibits a moderate increase characteristic. A code string having such an increasing characteristic is stored in advance in the instrument specific code string information holding unit 118 as an instrument specific code string for each gas instrument, and if compared with the measured code string at the time of increase, gas instrument C and gas The instrument D can be easily identified. If the magnitude relationship between the absolute amount of the difference value and the absolute value of the flow rate is also compared with the measurement code string, it is possible to accurately determine the appliance.

  FIG. 6 shows an example in which a gas appliance is discriminated by comparing the falling characteristics of the flow rate when the gas appliance is stopped (at the end of use of the gas). 6 (a) and 6 (b) show a table and a graph of changes in the usage flow rate from the start to the stop of the gas appliance E, and FIGS. 6 (c) and 6 (d) show the gas appliance F. The table and graph of the change of the usage flow from the time of starting to the time of stopping are shown.

  When the flow rate difference value immediately before the flow rate becomes zero in FIGS. 6A and 6B is coded, the code N1 is represented by “... 9DDC0” and the code N2 is represented by “. . Here, paying attention to “2220” of the code N2, it can be seen that the corresponding code N1 is “DDC0” and the falling characteristic of the gas appliance E is represented by a three-digit continuous code. Then, as can be seen from the code string “DDC0” of N2, it can be seen that the flow rate when the gas appliance E is stopped rapidly decreases twice, and finally decreases gradually and stops.

  When the flow rate difference value immediately before the flow rate becomes zero in FIGS. 6C and 6D is coded, the code N1 is represented by “... 9DD0” and the code N2 is represented by “. . Here, paying attention to “220” of the code N2, it can be seen that the corresponding code N1 is “DD0” and the falling characteristic of the gas appliance F is represented by a two-digit continuous code. As can be seen from the code string “DD0” of N2, it can be seen that the flow rate when the gas appliance F is stopped suddenly decreases twice and stops.

  If the falling characteristic as described above is stored in advance in the instrument specific code string information holding unit 118 as an instrument specific code string for each gas instrument, and compared with the measured code string at the time of decrease, the gas instrument E and the gas instrument F can be easily discriminated. If the magnitude relationship between the absolute amount of the difference value and the absolute value of the flow rate is also compared with the measurement code string, it is possible to accurately determine the appliance.

  The measurement code string and the instrument-specific code string may have a length until a specific code string pattern appears after the start of gas use by the gas instrument.

  For example, some gas appliances are used to repeatedly turn on and off combustion in order to perform room temperature control and hot water temperature control. By measuring the combustion on period, combustion off period, combustion on / off cycle time, etc. Some devices can identify and identify the characteristics of the appliance. In such a case, not only simply measuring the flow rate corresponding to one time period from the start (rise characteristic) to the stop (fall characteristic) of the gas appliance, but also the repetition from the start to the stop multiple times. When the flow rate is measured, the instrument can be identified as a specific code string pattern. For example, FIG. 7A shows the flow characteristics of the gas appliance G, and it can be seen that the combustion on and the combustion off are repeated in the second half.

  FIG. 7B shows an enlarged view of the change from point A to point B. As shown in FIG. 7C, the code N1 is represented by “... 8888888CDB00000000000033B33A92399AA99D88888DD0000000006623A... Here, the code N2 from the stop to the start of the next start is represented by “... 0001133”, and this pattern is measured again in the second half. In this case, repeated rising characteristics “... 0001133...” And the elapsed time therebetween (33 data × measurement cycle time (for example, 2 seconds) = 66 seconds) can be detected as the feature of the instrument. Therefore, the code string is continuously calculated until the use of the flow rate is completely stopped, and when the code string is measured with the same pattern next time with respect to the rise characteristic and the cycle time, it is determined that the instrument to be used is the gas instrument G. can do.

  In this way, it is possible to more reliably perform instrument discrimination using a pattern that repeatedly occurs in a measurement code string including a flow rate rising characteristic, a falling characteristic, a stable characteristic, and the like. The pattern that repeats may be a pattern that repeats at least two times, and if it can be determined, the number of repeats, timing, and periodicity are not limited. Will increase. In addition, by using the pattern repeatedly generated in the measurement code string and the appearance interval (time between patterns) of the pattern, it is possible to more reliably perform the instrument discrimination. When the pattern has periodicity, the discrimination accuracy is further increased by using the pattern that repeats periodically and the period of this pattern. As the cycle of the pattern, the length from the start of use of the fluid by the instrument (on time) to the next start of use (on time), the length from the end of use (off time) to the next end of use (off time), Using various times related to the cycle, such as the length from the start of use (ON time) to the next end of use (OFF time), the length from the end of use (OFF time) to the next start of use (ON time), etc. it can.

  As described above, the measurement code string according to the present invention handles data having a longer measurement time because the memory size is smaller even if the data is the same measurement time as compared to the history of the conventional difference values. It becomes easy. Therefore, it becomes easy to handle a flow rate change history corresponding to a long measurement time even when determining the appliance. By using a long-term flow rate change history, the accuracy of appliance discrimination can be improved.

  FIG. 8 shows another example of the flow rate classification table 110a. The flow rate classification table of FIG. 5 is different from that of FIG. In the example of FIG. 2, 16 divisions (code N1) and 4 divisions (code N2) are prepared in a range up to a difference value of 150 L / h, but in the example of FIG. 8, in a range up to a difference value of 30 L / h. Similarly, 16 sections (code N1) and 4 sections (code N2) are prepared. Therefore, the table in FIG. 8 is preferably used for discrimination when a gas appliance having a smaller flow rate (a gas appliance having a small absolute flow rate and a small change width) is activated compared to the table of FIG. For example, when a gas appliance having a flow rate Q (n) ≧ 200 L / h is used, the table of FIG. 2 is used, and when a gas appliance having a flow rate Q (n) <200 L / h is used, By using the table of FIG. 8, the gas appliance can be accurately identified.

  Further, the classification table may be switched and used according to the flow rate rising characteristics, control characteristics, and falling characteristics (stop characteristics).

  In order to carry out the flow rate measuring method as described above, the instrument discriminating unit 116 of the gas meter 100 and a computer (arithmetic unit) (not shown) store programs for executing the steps of the flow rate measuring method. In addition, a fluid supply system including a fluid (gas) supply source using a flow measurement device, a flow measurement method, and a program executed by a computer of the present invention is also included in the present invention.

  Although the above explanation has been given for the case where an ultrasonic flowmeter is used, it is obvious that the same effect can be obtained with other instantaneous flow measurement devices using a sampling signal. The processing after the device identification is omitted, but in the gas meter, the fee for each device by measuring the accumulated flow rate for each registered device or each classified group, and the safety management for each registered device or each classified group ( It is obvious that it is possible to set a security function for each device of the processing. In addition, if the gas meter and the gas appliance can be equipped with transmission / reception means such as a radio, it is clear that the accuracy of appliance discrimination is further improved. Furthermore, although it demonstrated with the gas meter and the gas appliance, it can use for the specification of the use appliance connected to the downstream of the flow measuring device, and its grouping similarly in an industrial flowmeter and a water meter.

  In the code N1 of the flow rate classification table (FIGS. 2 and 8) described above, the width of the differential flow rate in each subdivided region was different. However, it may of course be subdivided substantially equally in at least the increase region and the decrease region.

  Further, in the above-described embodiment, the difference value of the flow rate of the gas, which is a fluid, is the object to be coded. However, the object of encoding according to the present invention is not limited to the flow rate, and can be widely grasped as the physical quantity of the fluid such as the temperature, pressure, and mass of the fluid.

  Although various embodiments of the present invention have been described above, the present invention is not limited to the matters shown in the above-described embodiments, and those skilled in the art can make modifications and applications based on the description and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.

  As described above, according to the present invention, in order to convert the difference value into a code that is easier to handle, it is possible to reduce the amount of memory required for the apparatus and provide the calculation speed and the instrument while providing the discrimination technique of the fluid use instrument. It becomes possible to improve the discrimination accuracy.

Block diagram of a gas meter in an embodiment of the present invention Figure showing an example of flow rate classification table The figure which shows the concept which classifies the difference value of the flow volume by use of the gas appliance A according to a flow rate division table The figure which shows the concept which classifies the difference value of the flow volume by use of the gas appliance B according to a flow rate division table (A), (b) is a figure which shows the concept which classifies the difference value of the flow volume by use of the gas appliance C according to a flow rate division table, (c), (d) is the flow rate by use of the gas appliance D. The figure which shows the concept which classifies the difference value according to the flow classification table (A), (b) is a figure which shows the concept which classifies the difference value of the flow volume by use of the gas appliance E according to a flow rate division table, (c), (d) is the flow rate by use of the gas appliance F. The figure which shows the concept which classifies the difference value according to the flow classification table (A), (b) is a graph which shows the measurement flow volume of the gas appliance G, (c) is the figure which shows the flow volume division table | surface. Figure showing another example of flow rate classification table Block diagram of a conventional gas meter

Explanation of symbols

13, 14, 15 Gas appliance 19 Gas pipe line 100 Gas meter (flow rate measuring device)
DESCRIPTION OF SYMBOLS 102 Flow path 104 Ultrasonic flowmeter 106 Measurement flow volume information memory | storage part 108 Calculation part 110 Flow rate division table holding | maintenance part 112 Difference value conversion part 114 Code string production | generation part 116 Instrument discrimination | determination part 118 Instrument specific code string information holding part 120 Part 122 Channel shutoff valve

Claims (12)

A flow rate measurement unit for measuring the flow rate of the fluid flowing in the flow path at regular time intervals;
A calculation unit that calculates a difference value of the flow rate measured by the flow rate measurement unit for each predetermined time; and
A plurality of difference value categories according to the size of the difference value, a flow rate classification table in which codes representing each category are associated,
A difference value conversion unit that converts the difference value calculated by the calculation unit into the code based on the flow rate classification table;
A code string generation unit that generates a measurement code string based on the set of codes for each predetermined time obtained by the difference value conversion unit;
An instrument discriminating unit that discriminates an instrument that uses a fluid based on a pattern repeatedly generated in the measurement code string,
A flow rate measuring device comprising: The flow rate measuring device according to claim 1,
The measurement code string indicates a flow rate control characteristic during operation of the instrument. The flow rate measuring device according to claim 1,
The pattern in the measurement code string is a flow rate measuring device that is a pattern that repeats periodically. The flow rate measuring device according to claim 1,
The instrument discriminating unit is a flow rate measuring apparatus that discriminates an instrument based on a pattern repeatedly generated in the measurement code string and an appearance interval of the pattern. The flow rate measuring device according to claim 1,
The instrument discriminating unit is a flow rate measuring apparatus that discriminates an instrument based on a pattern that periodically repeats in the measurement code string and a cycle of the pattern. The flow rate measuring device according to claim 5,
The cycle of the pattern is a flow rate measuring device which is a length from the start of use to the start of the next use when the use start and end of use of the fluid by the instrument are repeated. The flow rate measuring device according to claim 5,
The cycle of the pattern is a flow rate measuring device having a length from the end of use to the end of next use when the start and end of use of the fluid by the instrument are repeated. The flow rate measuring device according to claim 5,
The cycle of the pattern is a flow rate measuring device that is a length from the start of use to the end of next use when the start and end of use of the fluid by the instrument are repeated. The flow rate measuring device according to claim 5,
The cycle of the pattern is a flow rate measuring device which is a length from the end of use to the start of the next use when the start and end of use of the fluid by the instrument are repeated. Measuring the flow rate of the fluid flowing in the flow path at regular time intervals;
A step of calculating a difference value of the measured flow rate for each predetermined time;
A step of converting the calculated difference value into the code based on a plurality of difference value categories according to the size of the difference value and a flow rate classification table in which a code representing each category is associated;
Generating a measurement code string based on the set of codes at the predetermined time;
Discriminating a device using fluid based on a pattern repeatedly generated in the measurement code string;
A flow measurement method comprising: A program for controlling a flow measuring device to execute the following steps,
Measuring the flow rate of the fluid flowing in the flow path at regular time intervals;
A step of calculating a difference value of the measured flow rate for each predetermined time;
A step of converting the calculated difference value into the code based on a plurality of difference value categories according to the size of the difference value and a flow rate classification table in which a code representing each category is associated;
Generating a measurement code string based on the set of codes at the predetermined time;
Discriminating a device using fluid based on a pattern repeatedly generated in the measurement code string;
A program that causes a computer to execute.   A fluid supply system using a flow rate measuring device or a flow rate measuring method according to claim 1, or a program executed by a computer.

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