JP4994875B2 - Gas appliance identification device - Google Patents

Description

  The present invention relates to a gas appliance discriminating apparatus installed in a gas supply line to each household and built in a gas meter having a gas flow meter, and more particularly to a gas appliance discriminating apparatus for discriminating a gas appliance in use. According to the gas appliance discriminating apparatus of the present invention, since the gas appliance in use can be discriminated with high accuracy from the time change pattern of the time differential value of the measured gas flow rate, an advanced security function is utilized using the discrimination result. Can be realized.

  A gas meter with a built-in gas flow meter is installed at the entrance of the gas supply line to each household. The gas meter measures the flow rate of gas passing through the gas supply line, and the measured gas flow rate is used for periodic gas charge calculation. In addition to the gas flow rate measurement function, the gas meter has a safety function of detecting an abnormal gas use state and shutting off the gas supply. According to this safety function, in response to detection of an abnormal state such as an earthquake, a gas leak, or forgetting to turn off the gas appliance, the shutoff valve provided in the gas flow path is closed to shut off the gas supply.

  In this case, it is desired to realize a different security function depending on the type of gas appliance. For example, a large water heater with a relatively large amount of gas consumption has a normal continuous use time that is not so long, and can be regarded as an abnormal state when it is continuously used for a predetermined time or longer. On the other hand, a stove or the like may be used continuously for a long time with a small gas flow rate, and it is not appropriate to make a judgment similar to a large water heater. It is also desirable to close the shutoff valve immediately when a gas leak occurs.

  Therefore, if the gas appliance in use can be discriminated from the measured value of the gas flow meter or gas pressure gauge of the gas meter, a security function suitable for the gas appliance can be realized.

  In Patent Document 1, for a plurality of types of gas appliances, partial flow patterns obtained by dividing a series of gas flow patterns generated in accordance with combustion control are classified into flow rate pattern tables classified for each control step, and corresponding to the gas appliances. A partial flow pattern for each control step and an instrument table having a gas flow rate are prepared in advance, and a partial flow pattern that matches the gas flow pattern detected by the gas flow meter is extracted and used from the combination of the extracted partial flow patterns. It has been proposed to identify the gas appliance inside.

That is, a plurality of partial flow patterns that can be taken by each gas appliance are registered in the appliance table, and the gas appliance in use is determined from a combination of partial flow patterns that match the detected flow rate pattern. By using the partial flow rate pattern, the matching accuracy with the detected flow rate pattern can be improved, and gas appliance discrimination with high accuracy is possible.
JP 2003-149019 A

  However, when performing gas appliance discrimination using partial flow pattern matching as a clue as in Patent Document 1, a plurality of gas appliances may have the same partial flow pattern, and a flow sensor or pressure sensor from the viewpoint of cost reduction. Sampling accuracy and measurement accuracy cannot be made so high, and partial flow patterns that match the detected flow pattern may not be extracted from the flow pattern table, which makes instrument discrimination impossible or incorrect. There is a possibility of making a determination.

  In particular, in the discrimination method based on the flow rate pattern, it is not always easy to distinguish the gas stove, household fuel cell, gas fan heater, and floor heating device from other gas appliances with high accuracy.

  Therefore, an object of the present invention is to provide a gas appliance discriminating apparatus with higher accuracy.

  Another object of the present invention is to provide a gas appliance discriminating apparatus capable of accurately discriminating and discriminating gas stoves, household fuel cells, gas fan heaters, and floor heating devices from other gas appliances.

  In order to achieve the above object, according to the present invention, in a gas appliance discriminating apparatus for discriminating a gas appliance in use, which is connected to the gas supply line, the flow rate of gas flowing through the gas supply line is determined. A flow rate detector to be detected, a device discrimination table having in advance a differential value pattern indicating a change with respect to time with respect to a time differential value of a gas flow rate generated with the use of the gas device, and the flow rate detection A differential value pattern that matches the differential value pattern of the detected gas flow rate detected by the vessel is extracted from the appliance discrimination table, and the gas appliance corresponding to the extracted differential value pattern in the appliance discrimination table is being used. Gas appliance discriminating means for discriminating from a gas appliance.

  According to said invention, the gas instrument which has a differential value pattern peculiar to an instrument can be detected with high precision by utilizing the differential value pattern which time differentiated the gas flow rate.

  In the above invention, according to a preferred aspect, the differential value pattern includes a time differential value of the gas flow rate, a length of time for which the predetermined time differential value continues, and the time differential value has a predetermined change. And the length of time that occurs.

  In the above invention, according to a preferred aspect, the flow rate detector detects the gas flow rate at a predetermined sampling rate and outputs a detected gas flow rate, and the gas appliance discriminating means smoothes the detected gas flow rate. The first time differential value is obtained by performing time differentiation without performing, and the second time differential value is obtained by time differentiation of the smoothed detection gas flow rate obtained by smoothing the detection gas flow rate by a predetermined time length, and the matching Is performed on the first and second differential value patterns with respect to the first and second time differential values. Preferably, the appliance discrimination table associates the first or second differential value pattern with the gas appliance corresponding to the plurality of types of gas appliances.

  By selecting the higher detection accuracy of the first or second differential value pattern for each gas appliance and registering it in the appliance discrimination table, higher discrimination accuracy can be obtained.

  According to the present invention, since the gas appliance in use is determined based on the differential value pattern indicating the change with respect to time with respect to the time differential value of the detected gas flow rate, a characteristic that can be clearly distinguished from other gas appliances. A gas appliance having a differential value pattern can be discriminated with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof.

  FIG. 1 is a configuration diagram of a gas meter incorporating a gas appliance discriminating apparatus according to the present embodiment. The gas meter 10 is provided between an external gas supply line 12 and an internal gas supply line 14 in the customer's house, and a shutoff valve 106, a gas pressure detector 104, and a gas flow rate detector 102 are provided in the gas supply path. And have. The gas flow rate detector 102 is preferably a sensor that can detect an instantaneous flow rate at a relatively short sampling rate (for example, every 2 seconds) such as an ultrasonic sensor. The control unit 108 is constituted by, for example, a microcomputer, integrates the gas flow rate from the gas flow rate data of the sampling rate detected by the gas flow rate detector 102, and obtains the gas consumption amount within a predetermined period. A gas appliance that discriminates the gas appliance in use by referring to the appliance discrimination table based on the storage means 114 that stores the appliance discrimination table and the gas flow rate data and the gas pressure data detected by the pressure detector 104. The determination unit 116 is configured.

  The gas consumption data accumulated by the control unit 108 is displayed on a display means (not shown) or transmitted from the communication unit 110 to a remote center. The control unit 108 executes a predetermined security function corresponding to the determined gas appliance. For example, when the use continues beyond the continuous use time set for each gas appliance, the center is notified via the communication unit 110, and the safety is confirmed by telephone contact from the center to the customer's house. Alternatively, when an abnormal usage pattern is detected, the control unit 108 forcibly controls the built-in shut-off valve 106 to be shut off. Alternatively, the control unit 108 forcibly controls the shutoff valve 106 even when a gas leak is detected.

  In the example of FIG. 1, a gas stove 18 for a kitchen, a floor heater (heat source device) 20, a gas fan heater 22, a fuel cell 24 and the like are connected to the gas supply line 14 at the customer house 16. The customer's home 16 is also connected to a gas stove, a hot water heater having a function of supplying hot water to a bath, and the like (not shown).

  Among gas appliances generally installed at customer's homes, water heaters and heat sources for floor heaters have a rising flow rate of 600 L / h or more at the start of use, whereas gas stoves, gas stoves, gas fan heaters, Household fuel cells and the like are lower than 600 L / h. Therefore, gas appliances that consume a large amount of gas, such as water heaters and heat source devices, and gas appliances that consume a small amount of gas, such as gas stoves, gas fan heaters, and household fuel cells, are compared with the rising flow rate at the start of use. Is easy to distinguish.

  On the other hand, gas stoves, gas fan heaters, household fuel cells, etc. have the same gas consumption, and gas stoves, gas fan heaters, household fuel cells, etc. generate specific gas flow patterns. Since manual control by the user is involved, any gas flow pattern can be generated, so the gas flow pattern cannot be predicted easily and cannot be easily distinguished from other gas appliances. Furthermore, it is not easy to distinguish gas stoves and household fuel cells from other gas appliances based on gas flow patterns.

  And it is not easy to distinguish the floor heater heat source from the water heater based on the gas flow rate pattern. Also, since a household fuel cell consumes a small amount of gas for a long time, it is not easy to distinguish it from gas leakage.

  In the case of gas appliances that have automatic control functions to some extent, such as gas stoves, gas fan heaters, and household fuel cells, safety equipment such as a turn-off prevention function is provided, but such equipment is not provided for gas stoves. In many cases, gas stoves need to be accurately identified from the viewpoint of security, along with gas leaks. Therefore, it is highly necessary to distinguish the use of a gas stove from gas leakage with high accuracy.

  In the present embodiment, a differential value pattern indicating a change with respect to time of a gas flow time differential value associated with combustion control or gas consumption control of each gas appliance is registered in advance in the appliance discrimination pattern table for each gas appliance. The differential value pattern that matches the differential value pattern of the detected gas flow rate from the gas flow rate detector 102 is extracted from the appliance discrimination pattern table, and the gas appliance corresponding to the extracted differential value pattern in the appliance discrimination table is being used. Distinguish from gas appliances.

  FIG. 2 is a diagram for explaining a flow rate pattern in the present embodiment. FIG. 2 shows the change (flow rate pattern) of the gas flow rate of a certain gas appliance with respect to time. The horizontal axis corresponds to time t, the vertical axis corresponds to the gas flow rate Q, and the gas flow rate Qrk detected by the gas flow rate detector 102 in the gas meter is shown. In this example, the gas appliance starts to be used at a certain time T1 and the gas flow rate rises to Qb. Thereafter, at a time T2, the gas flow rate Qrk is once decreased by a predetermined combustion control or use control, and further decreased, and thereafter the time T3. Is stable at a constant value.

  In the present embodiment, the time differential value is calculated from the gas flow rate detected between the rising time T1 and the time T3 (for example, 1 hour), and the differential value pattern indicating the change with respect to time of the time differential value is the gas pattern. A differential value pattern characteristic to the appliance is registered in advance in the appliance discrimination table for each gas appliance. Therefore, the characteristic differential value pattern is a pattern of the temporal differential value of the partial flow rate pattern generated in an arbitrary time zone from the rising time T1 to the time T3.

  The gas appliance discriminator of the present embodiment uses a sensor capable of detecting an instantaneous flow rate such as a gas flow rate sensor using ultrasonic waves as the gas flow rate detector 102, for example, at a sampling rate of 2 seconds. Detect the gas flow rate.

  However, high-frequency noise may be added to the gas flow rate depending on the operation control of some gas appliances. For such gas appliances, it is desirable to obtain a differential value pattern by time differentiation after smoothing the flow pattern of the detected gas flow for a predetermined time length to remove high frequency noise. On the other hand, depending on the gas appliance, a characteristic differential value pattern may be based on a flow rate pattern generated in a very short time. For such gas appliances, if a smoothing process is performed, a characteristic differential value pattern cannot be detected. Therefore, the flow rate pattern of the detected gas flow rate is time-differentiated as it is without a smoothing process to obtain a differential value pattern. It is desirable.

  Therefore, in the present embodiment, in the appliance discrimination table, the differential value pattern of the first time differential value obtained by performing time differentiation on the detected gas flow detected when using the gas appliance without performing the smoothing process, and a predetermined value One of the differential value patterns of the second time differential value obtained by time differentiation of the smoothed detection gas flow rate smoothed by the time length is registered according to the gas appliance. Then, the gas appliance discriminating means obtains a first time differential value by performing time differentiation on the detected gas flow without smoothing, and smoothing detection by smoothing the detected gas flow by a predetermined time length. The gas flow rate is time differentiated to obtain a second time differential value, and matching with the differential value pattern of the instrument discrimination table is performed for the first and second differential value patterns with respect to the first and second time differential values. By doing in this way, the characteristic differential value pattern can be used for appliance discrimination even in a gas appliance in which undesirable high frequency noise is superimposed on the detected gas flow rate.

  A specific matching process is performed by executing a determination program having a determination logic as to whether a differential value pattern obtained from the detected gas flow rate matches a registered differential value pattern.

  FIG. 3 is a flowchart showing the gas appliance discrimination procedure of the gas appliance discrimination means in the present embodiment. The gas appliance discrimination means records the gas flow rate data Qrk from the gas flow rate detector 102 together with the time t in the built-in memory as the measurement data DB1 (S10). At this time, the gas pressure data P from the gas pressure detector 104 is preferably recorded in the built-in memory as measurement data. However, in order to remove sensor noise and the like, the effective measurement data is that the detected flow rate Qkr at the sampling point or the average flow rate at the predetermined number of sampling points exceeds the reference value Q1 (S12). . Therefore, when the detected flow rate Qrk or the average flow rate becomes equal to or less than the reference value Q1, the measurement data up to that point is deleted (S14). Therefore, when it is detected that the detected flow rate Qrk or the average flow rate exceeds the reference value Q1 (YES in S12), it is detected that the use of any gas appliance has started or that a gas leak has started. The This is the start of use of the gas appliance and the rise of the gas flow rate. The detected flow rate Qrk is recorded until time T3 has elapsed (S16).

  When the period T3 elapses from the rise of the gas flow rate (YES in S16), the gas appliance determination means obtains the time differential value dQ from the measurement data DB1 so far without smoothing the detected gas flow rate Qrk at the sampling rate. Further, a smoothing process is performed to obtain a detected gas flow rate Qrk, for example, an average value for 30 seconds or an average value by a predetermined weighting ratio, and a time differential value dQa of the smoothed flow rate Qa is 30. It is calculated every second (S18).

  And the gas appliance discriminating means is an appliance discriminating table for two types of differential value patterns respectively indicating changes in the time differential value dQ of the unsmoothed detected gas flow rate Q and the time differential value dQa of the smoothed flow rate Qa. Matching is performed with the differential value pattern registered in DB2, and the gas appliance having the matching differential value pattern is determined as the gas appliance in use (S20).

  Hereinafter, a specific differential value pattern which a gas stove, a household fuel cell, a gas fan heater, and a gas floor heater have as a specific gas appliance will be described. FIG. 4 is a diagram showing a gas flow rate pattern (FIG. 4A) and a differential value pattern (FIG. 4B) of the gas stove. In the case of a gas stove, as shown in FIG. 4 (A), a typical gas flow rate pattern shows a steep rise (Q1), a steep fall (Q2) at the start of use, and a stable value ( Q3), suddenly descends at a certain point (Q4), and further stabilizes at a constant value (Q4). Although not shown, it may rise rapidly when the flow rate is stable at Q3. In any case, since the user manually controls the increase / decrease of the gas flow rate, the gas stove rapidly drops or rises within a relatively short time Ta (for example, 4 seconds). At the beginning of use, the gas flow is ignited at the maximum level and then decreases. This phenomenon also occurs within Ta for a short time.

  When the differential value of the gas flow rate is obtained, as shown in FIG. 4B, high differential values dQ1 and dQ2 are generated in a short time Ta, and further, a high differential value dQ4 is generated in a short time Ta. Therefore, the differential value pattern peculiar to the gas stove can be said to be a pattern in which a differential value exceeding the threshold value dQth within a short time Ta is generated.

  FIG. 5 is a diagram showing a gas flow rate pattern (FIG. 5A) and a differential value pattern (FIG. 5B) of a household fuel cell. Household fuel cells are composed of, for example, polymer electrolyte fuel cells (PEFC), and the city gas methane (CH4) is brought to a high pressure state by a booster and reacted with water in a high temperature state by gas combustion to generate hydrogen (H2). Electric power is generated by reaction with oxygen (O2) obtained from air. The domestic fuel cell needs to balance the pressure state and the high temperature state due to the above power generation mechanism, and the gas flow rate cannot be changed rapidly. That is, the gas flow rate in the case of a household fuel cell is controlled to rise or fall very slowly.

  In addition, since a household fuel cell continuously accumulates power over a long period of time to generate power that can supply the minimum power used in the home, its inherent gas flow pattern has a small gas flow rate (for example, 150 L). / H) continues for a long time (24 hours or more). In addition, currently popular gas meters have a safety function that forcibly shuts off the shut-off valve when a small gas flow rate continues for a long time. Therefore, in order to prevent the flow rate pattern of the household fuel cell from being determined as a gas leakage pattern by this security function, control is periodically performed to temporarily lower the gas flow rate and further increase it to the original flow rate.

  The gas flow rates Q11 and Q15 in FIG. 5A correspond to the small gas flow rate pattern that continues for a long time, and the decrease and increase (Q12, Q13, Q14) of the gas flow rate are the temporary decrease described above. And corresponding to the rising flow pattern. Therefore, a flow rate pattern peculiar to a household fuel cell is a pattern Q12 that slowly descends over a long period of time Tb (for example, 10 minutes).

  As shown in FIG. 5B, the differential pattern of the flow rate pattern has differential values dQ12 and dQ15 that are equal to or less than a predetermined threshold value dQth2 over a relatively long time Tb. Therefore, the differential value pattern in which the differential value dQ12 having a small threshold value dQth2 or less continues for a long time Tb can be said to be a differential value pattern unique to the home fuel cell.

  FIG. 6 is a diagram showing a gas flow rate pattern (FIG. 6A) and a differential value pattern (FIG. 6B) of the gas fan heater. The gas fan heater measures the room temperature and controls the fuel so that it becomes a set temperature. Normally, a proportional valve for controlling the gas flow rate is provided, and any of 7 to 8 stages of gas flow rates is selected by feedback control. Therefore, as shown in FIG. 6 (A), the gas flow rate rises in a short time Tc (for example, 4 seconds) to the maximum gas flow rate at the start of use (Q21), and the gas flow rate for a predetermined time Td (for example, 30 seconds). Is maintained (Q22), and the gas flow rate is reduced to a level corresponding to the set temperature over a relatively long time Te (for example, 15 seconds) by feedback control (Q23). Thereafter, a constant gas flow rate is maintained (Q24).

  As shown in FIG. 6B, the differential value pattern of the above flow rate pattern generates a high differential value dQ21 exceeding the threshold value dQth3 within a short time Tc, and generates a zero differential value dQ22 for a predetermined time Td. , And thereafter, a negative differential value dQ23 within the threshold value dQth4 is generated over a relatively long time Te. This can be said to be a differential value pattern unique to the gas fan heater.

  FIG. 7 is a diagram illustrating a gas flow rate pattern (FIG. 7A) and a differential value pattern (FIG. 7B) of the floor heater. In the floor heater, the heat source starts burning in response to the operation start command, and hot water at a predetermined temperature is circulated in a circulation pipe installed on the floor. Therefore, at the start of operation, it is necessary to burn a relatively large amount of gas in order to boil the cold water in the circulation pipe. However, only a relatively small amount of gas is burned after the temperature of the cold water in the circulation pipe rises during the first circulation. In the long term, the gas flow rate is maintained at a low value.

  As shown in FIG. 7A, at the start of operation, the gas flow rate rapidly increases (Q31) and once decreases (Q32). Thereafter, the gas flow rate gradually increases during a relatively long time Tf (for example, 5 minutes) (Q33), and further gradually decreases during a long time Tg (for example, 5 minutes) (Q34).

  As shown in FIG. 7B, the differential value pattern of the above flow rate pattern suddenly rises at the start of operation (dQ31) and suddenly falls to a negative value (dQ32). After that, it becomes a gentle positive value for a long time Tf (dQ33), and becomes a gentle negative value for a long time Tg via the zero cross point (dQ34). This is a differential value pattern unique to gas floor heaters.

  The characteristic differential value pattern for each gas appliance described above is registered in the appliance discrimination table in advance. Then, the gas discriminating means obtains a differential value pattern obtained by performing time differentiation without smoothing from the detected gas flow rate and a differential value pattern obtained by performing smoothing treatment and time differentiation by calculation. Is matched with the differential value pattern in the appliance discrimination table.

  Next, with respect to the above-described gas stove, household fuel cell, gas fan heater, and gas floor heater, the presence / absence of smoothing processing will be described with experimental data.

  FIG. 8 is a diagram showing an unsmoothed flow rate pattern Q and its differential value pattern dQ in a gas stove obtained in an experiment. That is, the flow rate pattern Q shows a change with respect to time of the instantaneous flow rate detected at a sampling rate of every 2 seconds of the gas flow rate detector. The horizontal axis corresponds to time, and the vertical axis corresponds to the flow value (upper) and the differential value (lower). In this differential value pattern, a high positive differential value dQ1 in a short time at startup and a high negative differential value dQ2 in a short time are generated, and a high negative (or positive) differential in a short time in the stable period. The value dQ4 has occurred. This coincides with the differential value pattern described in FIG.

  FIG. 9 is a diagram showing a smoothed flow rate pattern Qa and its differential value pattern dQa in a gas stove obtained in an experiment. The smoothing process is a process in which the detected gas flow rate for 30 seconds is weighted and averaged at the same ratio. In this case, the characteristic sudden drop and rise of gas flow in the gas stove in a short time is lost by the smoothing process, and the differential value pattern generated from the smoothed flow pattern has the characteristic differential value described above. The pattern is not found as much as in FIG.

  Therefore, the differential value pattern showing the characteristics of the gas stove is preferably a differential value pattern obtained by time-differentiating the undetected detected flow rate pattern.

  FIG. 10 is a diagram showing a smoothed flow rate pattern Qa and its differential value pattern dQa in a household fuel cell obtained in an experiment. In the case of a household fuel cell, it is necessary to pressurize the gas with a booster as described above, and minute high-frequency noise is superimposed on the detected gas flow rate by the operation of this booster. Therefore, it is preferable to smooth the detected instantaneous flow rate for a predetermined time length (for example, 30 seconds) and use a differential value pattern obtained by time-differentiating it. Since the characteristic of household fuel cells is a gradual decrease in gas flow rate, the characteristic flow rate pattern does not disappear due to the smoothing process. In the example of FIG. 10, a small negative differential value dQa12 is generated in a relatively long time, and is consistent with the differential value dQ12 of FIG.

  FIG. 11 is a diagram showing an unsmoothed flow rate pattern Q and its differential value pattern dQ in a gas fan heater obtained in an experiment. As shown in the figure, the gas fan heater is characterized in that the flow rate Q rises steeply, maintains a constant amount, and then decreases relatively slowly (Q23). The differential value pattern has a high value in a short time. dQ21, a zero value dQ22, and a relatively small negative value dQ23 for a relatively long time are generated. This is consistent with the description of FIG.

  FIG. 12 is a diagram showing a smoothed flow rate pattern Qa and its differential value pattern dQa in a gas fan heater obtained in an experiment. The smoothing process is a uniform average value for 30 seconds. As shown in the drawing, a relatively small negative value dQ23 of a relatively long time, which is a feature of the gas fan heater, disappears. Therefore, in the case of a gas fan heater, a differential value pattern obtained by time differentiation without smoothing is preferable. The gas fan heater is provided with a proportional valve, but its control stage is relatively small at 7 to 8, so the flow rate does not increase or decrease frequently, and the need for smoothing is low. .

  FIG. 13 is a diagram showing an unsmoothed flow rate pattern Q and its differential value pattern dQ in a floor heater obtained in an experiment. In the case of a floor heater, the water in the circulation pipe is heated by burning the heat source. In the heat source device, feedforward and feedback control are performed using a proportional valve, and the proportional valve is controlled at, for example, 20 or more flow levels. Therefore, high-frequency noise is generated in the gas flow rate controlled by the proportional valve. Therefore, if the detected instantaneous gas flow rate is not smoothed, high-frequency noise contained therein remains emphasized in the differential value pattern, and it is difficult to extract a characteristic differential value pattern.

  FIG. 14 is a diagram showing a smoothed flow rate pattern Qa and its differential value pattern dQa in a floor heater obtained in an experiment. The smoothing process is an operation for obtaining an average value of the equal ratio for 30 seconds as described above. As shown in the figure, the smoothed flow rate pattern Qa has a gentle rising pattern Qa33 and a gentle falling pattern Qa34. The time-differentiated differential value pattern dQa has a relatively long time plus value. Differential value dQa33 and a negative differential value dQa34 of a relatively long time are generated. This is consistent with the description of FIG. Therefore, in the case of a floor heater, a differential value pattern obtained by time-differentiating the smoothed flow rate value is preferable.

  As shown in FIGS. 8 to 14, the gas stove and the gas fan heater register the differential value pattern obtained by time differentiation without smoothing the detected flow rate in the appliance discrimination table, and the household fuel cell and the floor heater smooth the detected flow rate. It is desirable to register a differential value pattern obtained by performing time differentiation and time differentiation in the appliance discrimination table. In the appliance discrimination step, a differential value pattern obtained by time differentiation without smoothing the detected flow rate and a differential value pattern obtained by smoothing and time differentiation are calculated, and two types of differential value patterns are calculated in the appliance discrimination table. Performs matching processing with the differential value pattern. Thereby, matching processing can be performed with an optimum differential value pattern for each gas appliance.

  As described above, in the present embodiment, when detecting the gas flow rate to be consumed and determining the gas appliance in use based on the gas flow rate, the gas appliance is based on a differential value pattern obtained by time-differentiating the gas flow rate. Thus, it is possible to determine a gas appliance having a characteristic differential value pattern with high accuracy.

It is a block diagram of the gas meter which incorporates the gas appliance discrimination device in this Embodiment. It is a figure explaining the flow pattern in this Embodiment. It is a flowchart figure which shows the gas appliance discrimination | determination procedure of the gas appliance discrimination device in this Embodiment. It is a figure which shows the gas flow rate pattern and differential value pattern of a gas stove. It is a figure which shows the gas flow rate pattern and differential value pattern of a domestic fuel cell. It is a figure which shows the gas flow rate pattern and differential value pattern of a gas fan heater. It is a figure which shows the gas flow rate pattern and differential value pattern of a floor heater. It is a figure which shows the flow rate pattern Q and its differential value pattern dQ which are not smoothed in the gas stove obtained by experiment. It is a figure which shows the smoothed flow rate pattern Qa and its differential value pattern dQa in the gas stove obtained by experiment. It is a figure which shows the smoothed flow pattern Qa and its differential value pattern dQa in the household fuel cell obtained by experiment. It is a figure which shows the flow pattern Q (black triangle in a figure) and its differential value pattern dQ which are not smoothed in the gas fan heater obtained by experiment. It is a figure which shows the smoothed flow rate pattern Qa and its differential value pattern dQa in the gas fan heater obtained by experiment. It is a figure which shows the flow rate pattern Q and its differential value pattern dQ which are not smoothed in the floor heater obtained by experiment. It is a figure which shows the flow pattern Qa and the differential value pattern dQa which were smoothed in the floor heater obtained by experiment.

Explanation of symbols

10: Gas meter 12: Gas supply path 102: Gas flow rate detector 114: Appliance discrimination table 116: Gas appliance discrimination means

Claims (2)

A device connected to a gas supply line, wherein the gas appliance discriminating device discriminates a gas appliance in use.
A flow rate detector for detecting a gas flow rate flowing through the gas supply line at a predetermined sampling rate;
For each of a plurality kinds of gas appliances, the second differential value pattern of gas flow that occurs with showing a change with respect to time for a second time derivative of the smoothed smoothed gas flow at a predetermined time length to the use of the gas appliance Or an instrument discrimination table having in advance either a first differential value pattern indicating a change with respect to time for the first time differential value of the gas flow rate that is not smoothed;
The first and second differential value patterns matching the first and second detected differential value patterns with respect to the first and second time differential values of the detected gas flow rate detected by the flow rate detector are the instrument. A gas appliance discriminating apparatus having gas appliance discriminating means that discriminates a gas appliance that is extracted from a discrimination table and that corresponds to the extracted first or second differential value pattern in the appliance discrimination table from a gas appliance in use . In claim 1,
The differential value pattern has a size of a time differential value of the gas flow rate, a length of time for which the predetermined time differential value continues, and a length of time for which the time differential value causes a predetermined change. Gas appliance discriminating device.

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