JP2001281040A - Method for processing signal of gas meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent charge of an improper gas utilization rate to a gas consumer, due to gas utilization amount obtained, based on a actually measured flow rate within a flow rate unstable time in a gas meter having a shut-off valve 2 which is operable openably constituted during measuring of the flow rate, by disposing a gas flow rate detecting means 4 at a channel 1 to be measured, providing a flow rate counter 9 for integrating the flow rate based on a flow rate detection signal Sq from the means 4 and disposing the valve 2 at the inlet side of the channel 1. SOLUTION: The method for processing the signal of the gas meter comprises the steps of setting a correction flow rate of the actually measured flow rate within the flow rate unstable time to the flow rate unstable time set with respect to a specific time length with a time point of opening/closing the shut-of valve 2 as a start point, and correcting the integrated flow rate obtained by integrating the corrected flow rate at a prescribed time point, after the lapse of the flow rate unstable time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas flow detecting means provided in a measuring flow path, a flow counter for integrating a flow rate based on a flow detecting signal from the gas flow detecting means, The present invention relates to a signal processing method for a gas meter in which a shut-off valve is arranged on an inlet side and the shut-off valve can be opened and closed during a flow rate measurement.

[0002]

2. Description of the Related Art Conventionally, in a gas meter, for example, as shown in FIG. 9, a gas flow rate detecting means 4 arranged in a measurement flow path 1 is configured to oscillate a pulse at each set flow rate. The oscillating pulse is directly input to the flow counter 9 of the gas meter to integrate the flow rate. At the inlet of the measurement flow path 1, a shutoff valve 2 that can be opened and closed is provided, and when the gas flow rate detected by the gas flow rate detecting means 4 decreases, the shutoff valve 2 is temporarily closed. From the change in the instantaneous flow rate after the valve is opened, detection of gas leakage in the downstream gas flow path is performed.
The main purpose of the shut-off valve 2 is to, in the event of a gas leak in the downstream gas flow path, urgently shut off the gas supplied from the upstream side to prevent an accident from occurring on the downstream side. It is arranged as. For this purpose, a shut-off valve operating mechanism 3 is provided to open and close the shut-off valve 2 at a required time. The illustrated example is a gas flow meter using a fluidic element as the gas flow detecting means 4.

[0003]

Conventionally, in the above-mentioned gas meter, when the gas flow rate detected mainly by the gas flow rate detecting means 4 is small by the shut-off valve operating mechanism 3 during use of the gas meter, the gas flow rate is cut off. Opening and closing the valve 2 to shut off the flow path and check for gas leakage in the downstream flow path are performed. The closing operation of the shut-off valve 2 is performed for a short time, and the leak of the downstream flow path is detected from the change in the flow rate after the restart of the shut-off valve 2. However, it is affected by the operation of the shut-off valve 2. And the measurement channel 1
Since the gas flow flowing through the turbulence causes turbulence, there is a time until the turbulence is settled as the unstable flow time. During the unstable flow time, the accuracy of the measured flow rate detected by the gas flow rate detecting means 4 is reduced due to the turbulence of the gas flow, and the integrated flow rate integrated in the flow counter 9 becomes inaccurate. There is a possibility that the gas usage fee for the house will be inappropriate and different from the actual gas usage.
The same applies to a case where the shut-off valve 2 is closed and the shut-off valve 2 is opened again after detecting an abnormality.

Further, the gas flow rate detecting means 4 does not have a completely linear oscillation frequency of the flow rate detection signal Sq over the entire flow rate measuring range. For example, as shown in FIG. In the vicinity of the upper limit and the lower limit of the flow rate measurement range, the linearity is lost, and the slope generally has a characteristic that the gradient is somewhat reduced. For this reason, unless the flow rate measurement range is somewhat narrowed, it is necessary to correct the flow rate measurement result in this non-linear region, but conventionally, sufficient correction has not been made.

By the way, the flow rate measurement range of the gas meter is
For example, as shown in FIG. 4, in addition to the main flow path 1A in which the gas flow rate detecting means 4 is disposed, a gas flow rate detecting means is disposed in order to expand the flow rate range larger than the flow rate detection range of the gas flow rate detecting means. Instead, the inventors came to consider providing a sub flow path 1B in parallel with the main flow path 1A and also providing a shutoff valve 2B on the inlet side of the sub flow path 1B. In the same manner as described above, the shutoff valve 2B is opened and closed during the flow measurement according to the change in the gas usage, and the sub flow path 1B has the flow unstable time after the opening and closing operation of the shutoff valve 2B. It is thought that there is. Therefore, if an attempt is made to adopt a new configuration of such a gas meter, the flow rate in the main flow path 1A is also affected by the opening / closing operation of the shut-off valve 2B due to a change in gas usage, and the gas flow rate
The inventors have come to think that there is a possibility that the accuracy of the measured flow rate may decrease due to the above.

Therefore, an object of the signal processing method for a gas meter according to the present invention is to determine an amount of gas consumption based on a flow rate actually measured during the unstable time of the flow rate. Another object of the present invention is to provide a means for preventing a customer from being charged.

[0007]

[Means for Solving the Problems]

[0008] [Characteristics of the present invention] A characteristic of a signal processing method for a gas meter according to the present invention is that gas flow detecting means is arranged in a measurement flow path, and a flow rate is determined based on a flow detection signal from the gas flow detecting means. A flow counter that integrates
A gas shutoff valve is arranged on the inlet side of the measurement flow path, and the gas shutoff valve is configured to be opened and closed during flow rate measurement. On the other hand, the present invention is characterized in that the integrated flow rate integrated in the flow counter is corrected using the corrected flow rate, and each has the following characteristics.

The first characteristic means of the signal processing method for a gas meter according to the present invention is characterized in that the flow rate instability time set to a specific time length starting from the time of opening / closing operation of the shutoff valve is defined as the starting point. Setting a corrected flow rate for the actually measured flow rate within the unstable flow rate time, and using the corrected flow rate to correct the integrated flow rate integrated in the flow counter at a predetermined time after the elapse of the flow rate unstable time. It is in.

The second characteristic means of the signal processing method for a gas meter according to the present invention is based on the measured flow rate before, after or before or after the flow instability time in the first characteristic means. The present invention is characterized in that an estimated flow rate within the unstable flow rate time is obtained, and a corrected flow rate is set so that an actually measured flow rate within the unstable flow rate time matches the estimated flow rate.

According to a third feature of the signal processing method for a gas meter according to the present invention, the measuring flow path is defined as follows.
The main flow path in which the gas flow rate detecting means is disposed, and the main flow path is provided in parallel to the main flow path without disposing the gas flow rate detecting means, and the flow path resistance is set to a specific ratio with respect to the flow path resistance of the main flow path. The gas flow rate detection means is constituted by at least one sub-flow path, comprising a shut-off valve on the inlet side of the measurement flow path, and opening and closing the cut-off valve provided in the sub-flow path during flow rate measurement. It is configured so that the flow rate detection magnification can be changed,
When measuring a gas flow rate using a gas meter having a flow rate counter that integrates a flow rate based on a flow rate detection signal from the gas flow rate detection means, starting from the earliest time point of the opening and closing operation of a shutoff valve provided in the sub flow path With respect to the flow unstable time set to a specific time length, an estimated flow within the flow unstable time is obtained based on the measured flow before, after or before or after the flow unstable time, and the flow unstable. After the lapse of time, the integrated flow rate integrated in the flow counter is corrected by a corrected flow rate set so that the actually measured flow rate within the unstable flow rate time matches the estimated flow rate.

According to a fourth feature of the signal processing method for a gas meter according to the present invention, the flow rate is detected by a flow counter during a flow unstable period in the second or third feature means. The point is that the input of the signal is stopped and the estimated flow rate is added as the corrected flow rate to correct the integrated flow rate integrated in the flow counter.

According to a fifth aspect of the signal processing method for a gas meter according to the present invention, the predetermined time point for correcting the integrated flow rate in any one of the first to fourth characteristic means is provided. The point is that the shut-off valve arranged on the inlet side of the measurement flow path is closed, and the time period is set so that the flow rate detection signal is not oscillated from the gas flow rate detection means.

According to a sixth aspect of the signal processing method for a gas meter according to the present invention, the gas flow rate detecting means is disposed in the measurement flow path, and the flow rate detecting signal from the gas flow rate detecting means is provided. In a gas meter provided with a flow counter that integrates the flow rate based on, a calibration curve of the gas flow detection means is obtained in advance, and a short-time flow detection value of the gas flow detection means is compared with the calibration curve, The point is that, based on the comparison result with the calibration curve, a correction input signal Sa is added to the input signal to the flow counter according to the comparison result to correct the integrated flow to be integrated in the flow counter.

[Function and Effect of Characteristic Means] According to the characteristic means of the signal processing method for the gas meter according to the present invention, the integrated flow rate integrated in the flow counter is corrected for the measured flow rate during the flow unstable time. Once a large error has occurred in the flow rate detection signal from the gas flow rate detection means, this can be made to be an integrated flow rate that is close to the actual flow rate. It works.

According to the first characteristic means of the signal processing method of the gas meter according to the present invention, the integrated flow rate accumulated in the flow counter can be correctly maintained even when the flow rate is unstable during the flow rate measurement. That is, at a predetermined time after the elapse of the flow rate unstable time, the integrated flow rate integrated up to that time is corrected by the corrected flow rate set after the unstable flow rate time, thereby obtaining the integrated value based on the flow rate measurement result. Flow rate can be corrected,
After the predetermined time point, the integrated flow rate has a predetermined flow rate value.

According to the second characteristic means of the signal processing method for a gas meter according to the present invention, the calculation load can be reduced while the operation and effect of the first characteristic configuration are exhibited. That is, since the estimated flow rate within the flow unstable time is obtained based on the measured flow rate before, after, or before or after the flow unstable time,
The estimated flow rate can be estimated by a simple calculation. For example, the estimated flow rate may use the measured flow rate before the flow unstable time as it is, or may use the measured flow rate after the flow unstable time as it is, The measured flow before and after may be averaged.

According to the third feature of the signal processing method for a gas meter according to the present invention, the gas meter is composed of a main flow path in which the gas flow rate detecting means is arranged, and a sub flow path provided in parallel with the main flow path. Even when the flow of gas to the sub flow path is configured to be selectable and the shut-off valve provided in the sub-flow path is configured to be opened and closed during the flow rate measurement, it is assumed that the shut-off valve is opened and closed. Even if a gas flow rate error occurs, the error can be avoided. In other words, if the on-off valve provided in the sub flow path is operated, the flow rate fluctuation in the sub flow path may cause a transient flow rate fluctuation in the main flow path. Since the uncertain fluctuation in the flow rate detection signal from the detection means occurs during the above-mentioned unstable flow rate time, the integrated flow rate is maintained at a normal value by correcting using the corrected flow rate after the flow rate unstable time has elapsed. It becomes possible.

According to the fourth feature of the signal processing method for a gas meter according to the present invention, the second feature configuration or the third
The integrated flow rate can be easily corrected while exhibiting the function and effect of the characteristic configuration. That is, during the unstable flow time, the integrated flow is corrected by using the estimated flow obtained by estimating the flow during that time, regardless of the actual flow during that time, assuming that the flow during the unstable flow time is the estimated flow. You do it.
As a result, the power consumption required for the correction process can be reduced, and the battery life of the gas meter can be maintained longer.

According to the fifth feature of the signal processing method for a gas meter according to the present invention, the calculation for correcting the flow counter can be performed while exhibiting the effect of any one of the first to fourth features. The load can be reduced. In other words, while the shut-off valve arranged at the entrance of the measurement flow path is closed,
Since the integrated flow rate is corrected during a time period in which the flow rate detection signal from the gas flow rate detection means is not oscillated, there is no calculation load without correction, and even if the correction calculation is performed, the calculation load does not become large. .

According to the sixth characteristic means of the signal processing method for a gas meter according to the present invention, it can be used even when the flow rate detection signal of the gas flow rate detecting means does not have linearity over a wide range. That is, the normal gas flow rate detection means uses an area in which the flow rate detection signal has linearity with respect to the measured flow rate as a flow rate measurement range, and sets an amount proportional to the flow rate detection signal as the gas flow rate. By determining a calibration curve of the gas flow rate detection means in advance, a range having linearity is determined, and a short-time flow rate detection value based on a flow rate detection signal from the gas flow rate detection means is compared with the calibration curve. If it is determined that the short-time flow rate detection value is in the range not having the linearity, a correction input signal corresponding to a deviation from the straight line is input to the flow rate counter to perform correction. If the flow rate detection signal is a pulse signal, the flow rate can be integrated by integrating the number of pulses.However, in a region having no linearity, the flow rate detection signal is used as a correction input signal corresponding to the deviation. It is only necessary to insert an addition signal or a subtraction signal, or an addition command or a subtraction command may be input to the flow counter as the correction input signal. This correction input signal may be input at an appropriate time.For example, the correction amount is accumulated in a correction counter, and the correction input signal is output so that the content of the correction counter approaches zero at a time when the gas flow rate is small. You may. In this way, since the calculation load is low, even if the correction operation is performed in parallel with the detection of the gas flow rate, the calculation load is not particularly large.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the signal processing method for a gas meter according to the present invention will be described below with reference to the drawings. Note that the same elements as those described in the related art and elements having the same functions are denoted by the same reference numerals as those in FIGS. 9 and 10, and a part of the detailed description is omitted. .

[First Embodiment] As shown in FIG. 1, for example, a gas meter has a gas flow detecting means
And a flow counter 9 for integrating the flow rate based on the flow rate detection signal Sq from the gas flow rate detecting means 4 is provided.
A shutoff valve 2 is arranged on the inlet side of the measurement flow path 1 so that the shutoff valve 2 can be opened and closed during flow rate measurement. This shutoff valve 2 is, as described above in the section of the prior art,
At a time when the gas flow rate detected by the gas flow rate detecting means 4 becomes small, the gas flow rate is temporarily closed. The main purpose is to detect and prevent an accident from occurring on the downstream side when a gas leaks in the downstream gas flow path.

The closing and opening of the shut-off valve 2 for detecting the gas leakage may be performed during the use of the gas on the downstream side even though the gas flow rate is low. As a result of instability of the flow rate in the measurement flow path 1 after the operation, an error occurs in the integrated flow rate. Therefore, for a flow unstable time set to a specific time length starting from the time of opening / closing operation of the shutoff valve 2, a correction flow for an actually measured flow within the flow unstable time is set, and the corrected flow is used. Then, at a predetermined time after the elapse of the unstable flow time, the integrated flow rate accumulated in the flow counter 9 is corrected. The illustrated gas flow rate detecting means 4 is constituted by a fluid vibration type flow meter using a fluidic element. Incidentally, the gas flow rate detecting means 4 includes:
A flow meter or a fluid vibration type flow meter using a fluidic element can be exemplified. The flow rate detection signal Sq from the gas flow rate detecting means 4 is a digital signal, and a pulse oscillated at a frequency proportional to the detected gas flow rate. Signal.

The corrected flow rate is obtained based on the measured flow rate before and after the unstable flow rate, and calculates the estimated flow rate within the unstable flow rate time, and the measured flow rate within the unstable flow rate time matches the estimated flow rate. Set as follows. For example, the corrected flow rate is obtained as an average value of measured flow rates before and after the flow unstable time. At a predetermined time when the integrated flow rate is corrected, when the shut-off valve 2 disposed on the inlet side of the measurement flow path 1 is closed to detect gas leakage in the downstream flow path, the gas flow rate detection is performed. It is set to a time zone in which the flow rate detection signal Sq is not oscillated from the means 4.

In this specific example, the integrated flow rate is read by the flow counter 9 every second and the difference of the integrated flow rate per second is obtained as shown in FIG.
This is temporarily stored in the difference register 8. Based on the estimated flow rate Qe (see FIG. 3) from the contents of the difference register 8, a corrected flow rate Qa is calculated by the flow rate correction value calculation section 6 and integrated in the correction register 7. If the corrected flow rate Qa integrated in the correction register 7 exceeds a predetermined value, the measured flow rate Qr detected by the gas flow rate detecting means 4 decreases, and the correction flow rate signal Sq becomes coarse. When the corrected flow rate Qa is a positive value, the correction register 7 is decremented (incremented when the corrected flow rate Qa is a negative value) so that the corrected flow rate Qa integrated into the value 7 becomes zero. An addition pulse signal is input to the flow counter 9 as the input signal Sa (if the correction flow rate Qa is a negative value, a subtraction pulse signal is input to the flow counter 9).
Instead of inputting the addition pulse signal or the subtraction pulse signal to the flow counter 9, an increment operation or a decrement operation may be directly added to the flow counter 9.

A specific example will be described. For example, FIG.
As shown in FIG.
The gate 9a is shut off and the flow rate of the measured flow rate Qr is reduced.
Mask the integration to the counter 9. On the other hand, the flow rate is unstable
Time Tu and before (t_{k- 1}+ Δt) and after (t_{n + 1}
+ Δt) measured flow rate Q stored in the difference register 8
An average is calculated for r, and based on this,
Estimated instantaneous flow rate by linear interpolation within Tu (indicated by broken line in the figure)
The estimated flow rate Qe is calculated as the integrated value of
This is the positive flow rate Qa. The estimated flow rate Qe is
As the area below the broken line, the corrected flow rate Qa is represented by a two-dot chain line.
Time t_k~ T _nShown between
Was.

The start of the unstable flow time (in this case,
As shown in FIG. 2, for example, as shown in FIG. 2, the shut-off valve 2 is provided so that the shut-off operation of the shut-off valve 2 provided on the upstream side of the measurement flow path 1 can be detected.
Determining means 10 including a state determining unit 11 for determining the state of
Is provided to detect the opening / closing operation of the shut-off valve 2 by the shut-off valve operating mechanism 3 and to open / close the shut-off valve 2 according to the situation. Then, the pulse input gate 9a is provided between the flow rate pulse output section 4a of the gas flow rate detecting means 4 and the flow rate counter 9 to detect the opening / closing operation of the shut-off valve 2, and then the predetermined time length is set in advance. During the set flow instability time (refer to FIG. 3 and denoted by Tu in the figure), the flow rate detection signal Sq is masked by the pulse input gate 9a. The corrected flow rate Qa during the unstable flow rate Tu is obtained by measuring the measured flow rate Qr immediately before the flow unstable time Tu stored in the difference register 8 immediately before shutting off the pulse input gate 9a and the flow unstable time T1.
Using the estimated flow rate Qe calculated as the average flow rate with the measured flow rate Qr immediately after the elapse of u, the correction flow rate is temporarily stored in the correction register 7 and the number of pulses corresponding to the unit flow rate is output to the flow counter 9. I do.

By the way, as described in the section of the prior art, the gas flow rate detecting means 4 generates the oscillating flow rate detection signal Sq over the entire flow rate measuring range as shown in FIG. It is not completely linear. Therefore, the calibration curve L of the gas flow detecting means 4 is obtained in advance. For example, as shown in FIG.
0, the pulse interval of the flow rate detection signal Sq input to the flow rate counter 9 is estimated from the measured flow rate Qr stored in the difference register 8, and the short-time flow rate is determined based on the pulse interval. The detection value q is obtained. The instantaneous flow rate determination unit 12 compares the instrumental error data map storing the calibration curve L with the short-time flow rate detection value q, and determines whether the short-time flow rate detection value q is within the linear range based on the comparison result. Determine whether or not. At the same time, the flow rate correction value calculation unit 6
The flow rate correction value ΔQ is obtained from the deviation of the short-time flow rate detection value q from the calibration curve L, and is output to the correction register 7.

When the instantaneous flow rate determination unit 12 determines that the short-time flow rate detection value q is out of the linear range and needs to be corrected, an input signal to the flow rate counter 9
That is, for the flow rate detection signal Sq, the flow rate correction value Δ
Q is input to the correction register 7. The correction input signal Sa corresponding to the flow rate correction value ΔQ input to the correction register 7
Is added to the flow counter 9 to correct the integrated flow rate (indicated by the symbol Qs in the figure).
Then, the integrated flow rate Qs after the correction is integrated. For example, in the correction input signal Sa, a number of pulses corresponding to the flow rate correction value ΔQ are inserted between the pulses of the flow rate detection signal Sq. When a subtraction correction is required, a subtraction command may be input to the flow counter 9 as the correction input signal Sa.

[Second Embodiment] As shown in FIG. 4, for example, as shown in FIG. 4, a gas flow meter has a main flow path 1A in which a gas flow rate detecting means 4 is disposed and a gas flow rate detecting means. The main flow path 1A is provided in parallel with at least one sub flow path 1B having a flow path resistance set to a specific ratio with respect to the flow path resistance of the main flow path 1A. An inlet side, that is, a shutoff valve 2A disposed on the upstream side of the branch to the sub flow path 1B, and a shutoff valve 2B disposed on the sub flow path 1B downstream of the branch part are provided. . These shut-off valves 2 (2A, 2B) are configured to be openable and closable even during the flow rate measurement by the gas flow rate detecting means 4. By opening and closing a shutoff valve 2B provided on the inlet side of the sub flow path 1B during the flow rate measurement, the flow rate detection magnification of the gas flow rate detecting means 4 can be changed. Further, there is provided a flow rate counter 9 for integrating the flow rate based on the flow rate detection signal Sq from the gas flow rate detecting means 4. That is, unlike the first embodiment, the flow rate detection signal Sq from the gas flow rate detecting means 4 includes the flow rate detection signal Sq depending on the state of the shutoff valve 2B provided on the inlet side of the sub flow path 1B, that is, the main flow path. By changing the ratio of the conductance of the entire measurement flow path 1 to the conductance of 1A, the ratio of the gas flow rate flowing through the entire measurement flow path 1 to the gas flow rate flowing through the main flow path 1A is changed, and the flow rate detection signal Sq The weights for the flow rates are different. Here, the formats of the gas flow rate detecting means 4 and the flow rate detection signal Sq are the same as those described in the first embodiment.

Also in the gas meter, the shut-off valve 2A disposed on the inlet side of the measurement flow path 1 causes gas leakage in the downstream gas flow path as described in the first embodiment. In this case, the main purpose is to prevent the occurrence of an accident on the downstream side in the event of a collision. As described above, when the gas flow rate detected by the gas flow rate detecting means 4 decreases, the gas flow rate is temporarily closed, and from the change in the instantaneous flow rate after the valve is opened, the gas flow rate on the downstream side is determined. It is also used to detect gas leaks in roads.

The opening / closing operation of the shut-off valve 2B provided in the sub flow path 1B is performed while the gas is being used on the downstream side, that is, during the flow rate measurement by the gas flow rate detecting means 4. That is, since the opening / closing operation of the shutoff valve 2B is performed while the gas is being used on the downstream side, the flow rate in the main flow path 1A may be unstable after the opening / closing operation. Therefore, the flow rate set to a specific time length starting from the opening / closing operation of the shutoff valve 2B provided in the sub flow path 1B (in this case, the opening or closing operation of the cutoff valve 2B provided in the sub flow path 1B). With respect to the unstable time Tu, the estimated flow rate within the unstable flow rate Tu is calculated as an average value of the measured flow rates Qr before and after the unstable flow rate Tu based on the measured flow rates Qr before and after the unstable flow rate Tu. Find Qe. After the elapse of the unstable flow rate Tu, the integrated flow rate Qs integrated in the flow counter 9 by the correction flow rate Qa set so that the actually measured flow rate Qr within the unstable flow rate time Tu matches the estimated flow rate Qe. Is corrected. For this purpose, for example, the input of the flow rate detection signal Sq to the flow rate counter 9 is stopped during the unstable flow rate Tu, and the integrated flow rate Qs integrated in the flow rate counter 9 using the estimated flow rate Qe as the corrected flow rate Qa. To the integrated flow rate Qs
Is corrected. At a predetermined time when the integrated flow rate Qs is corrected, the gas flow rate detecting means is in the gas leakage detection mode for the downstream flow path in which the shutoff valve 2A disposed on the inlet side of the measurement flow path 1 is closed. 4, the time period during which the flow rate detection signal Sq is not oscillated is set. The processing of the flow rate detection signal Sq is the same as that described in the first embodiment.

[Another Embodiment] Another embodiment of the signal processing method for a gas meter according to the present invention, which has not been described in the above embodiment, will be described below.

<1> In the above embodiment, the fluid flow type flow meter or the flow meter has been described as an example of the gas flow rate detecting means 4.
An ultrasonic flow meter or another type of gas flow meter may be used.

<2> In the above embodiment, the flow rate detection signal Sq from the gas flow rate detection means 4 is a digital signal composed of pulse signals oscillated at a frequency proportional to the detected gas flow rate. As described above, the flow rate detection signal Sq may be a digitized digital signal,
Alternatively, it may be an analog signal. In the former case, the flow rate counter 9 may be configured as a register, and the flow rate correction process adds digital data quantified with respect to the corrected flow rate Qa to the flow rate counter 9 configured as a register. do it. In the latter case, the flow rate detection signal Sq may be FM-modulated and pulse-converted and input to the flow rate counter 9. The data on the corrected flow rate Qa is also input to the flow rate counter 9 as a required number of pulses. The flow rate counter 9 may be configured as a register, and the flow rate detection signal Sq may be A / D-converted and input to the flow rate counter 9 as digitized digital data. The signal Sa may be added to the flow counter 9 by digitized digital data relating to the corrected flow rate Qa as the flow rate correction value ΔQ. Regarding the flow rate correction processing, regardless of the format of the flow rate detection signal Sq,
The flow counter 9 may be incremented or decremented a required number of times corresponding to the corrected flow rate Qa.

<3> In the above embodiment, the corrected flow rate Qa is obtained as an average value of the measured flow rate Qr before and after the flow unstable time Tu, and the estimated flow rate Qe within the flow unstable time Tu is obtained. During the unstable flow time Tu, the input of the flow detection signal Sq from the gas flow detecting means 4 to the flow counter 9 is stopped, and the estimated flow Qe within the unstable flow time Tu is stopped.
Is added as the corrected flow rate Qa to obtain the integrated flow rate Qs
Has been described, the estimated flow rate Qe within the flow unstable time Tu is determined from the measured flow rate Qr before or after the flow unstable time Tu, and the flow unstable time Tu is calculated.
The corrected flow rate Qa may be set so that the actually measured flow rate Qr in the above-mentioned range matches the estimated flow rate Qe. For example, the measured flow rate Qr before or after the unstable flow rate Tu may be used as the estimated flow rate Qe within the unstable flow rate Tu. In order to prevent the gas consumer from being charged an excessive gas usage fee, the smaller of the measured flow rates Qr before or after the unstable flow rate Tu may be used as the estimated flow rate Qe.

<4> In the above embodiment, the difference of the integrated flow rate per second is obtained, and the difference is temporarily stored in the difference register 8, and the corrected flow rate is calculated from the contents of the difference register 8 based on the estimated flow rate Qe. An example in which Qa is calculated by the correction flow rate calculation unit 6 and integrated in the correction register 7 has been described.
As shown in the figure, the flow rate detection signal Sq is input to the instantaneous flow rate detection unit 5, and the flow rate detection signal Sq
The instantaneous flow rate determination unit 12 of 0 detects the short-time flow rate detection value q to obtain the actually measured flow rate Qr, and the flow rate correction value calculation unit 6 estimates the estimated flow rate Qe.
a may be calculated and output to the correction register 7. In this case, the flow rate detection signal S shown in FIG.
For a region where q does not have linearity, the calibration curve L of the gas flow rate detecting means 4 is obtained in advance and stored as an instrumental difference data map, for example, as shown in FIG. The short-time flow rate detection value q is detected from the flow rate detection signal Sq input to the detection unit 5, and the short-time flow rate detection value q is stored in the instantaneous flow rate determination unit 12 in which the calibration curve L is stored. Is determined based on the comparison result to determine whether or not the short-time flow rate detection value q is within the linear range.
The flow rate correction value ΔQ can be obtained from the deviation of the calibration curve L from the calibration curve L.

<5> As shown in FIG. 6, the instantaneous flow rate detection unit 5 stores the flow rate detection signal Sq in a bit register configured as a shift register or an annular register.
And the flow rate detection signal Sq
The flow rate detection signal Sq is input at a predetermined time interval smaller than the interval at which the clock signal is oscillated, and the total value of the specific width (number of digits) of the bit register is output to the counter. The specific value may be sequentially shifted, and the total value may be output to the counter. Based on the total value output to the counter, the short-time flow rate detection value q of the gas in the measurement flow path 1 can be detected as the actually measured flow rate Qr.

<6> In the above embodiment, the corrected flow rate Qa is obtained as an estimated instantaneous flow rate which is linearly complemented between the actually measured flow rate Qr before and after the flow instability time Tu. Measured flow rate Qr before and after stabilization time Tu
Of the estimated flow rate Q within the flow unstable time Tu
The input of the flow rate detection signal Sq from the gas flow rate detecting means 4 to the flow rate counter 9 is stopped during the unstable flow rate Tu, and the estimated flow rate Qe within the unstable flow rate Tu is added as the corrected flow rate Qa. Although the example which corrects the said integrated flow rate Qs by doing was demonstrated, for example, as shown in FIG.
Even during the unstable flow time Tu, the accumulation of the measured flow rate Qr to the flow counter 9 is continued based on the flow rate detection signal Sq. On the other hand, the flow unstable time Tu and before (t _k-1 + Δt) and after (t _{n + 1} + Δt)
Is, for example, a stack register 13 (F
IFO), the flow rate detection signal Sq is integrated at every set time interval (Δt). The correction flow rate Qa for the integrated value of the flow unstable time Tu integrated in the stack register 13 is obtained, and the integrated flow rate Qs is corrected. Note that the number of stacks in the figure and the value of data in each stack do not always match those in FIG. Furthermore, before the flow unstable time Tu,
The average of the measured flow rate Qr integrated on the stack corresponding to (tk _-1 + Δt) and the subsequent (tn _{+ 1} + Δt) is obtained as an estimated flow rate Qe within the unstable flow rate Tu, and this and the flow rate The difference from the integrated value of the unstable time Tu is obtained as the corrected flow rate Qa. The estimated flow rate Qe is shown in FIG.
At the time t _{k to} t _n (before (t _k-1 + Δt) and after (t _{n + 1} + Δt) the flow unstable time Tu.
This corresponds to a linear interpolation between the measured flow rates Qr integrated in the stack corresponding to t). ), And the corrected flow rate Qa is calculated by calculating the difference between the flow rate unstable time Tu and the solid line (corresponding to the integrated flow rate Qs of the flow rate unstable time Tu). Equivalent to.

<7> Instead of the above <6>, the flow rate detection signal Sq is formed in an annular shape while sampling the instantaneous flow rate detection unit 5 at a predetermined time interval smaller than the interval at which the flow rate detection signal Sq is oscillated. The bits are input to the bit register while changing bits in accordance with the sampling clock, and the total value of the specified number of digits of the bit register is output to the counter while sequentially shifting one bit to the counter. Based on the total value output to the counter, The short-time flow rate detection value q is compared with the measured flow rate Q
Although an example in which detection is performed as r is shown in FIG. 6, the shift width of the bit register may be set as appropriate. Further, instead of the bit register, a plurality of registers for inputting the short-time flow rate detection value q from the flow rate detection signal Sq at short time intervals may be provided.

<8> In the above embodiment, the corrected flow rate Qa is obtained as an average value of the measured flow rate Qr before and after the flow unstable time Tu, and the estimated flow rate Qe within the flow unstable time Tu is obtained. During the unstable flow time Tu, the input of the flow detection signal Sq from the gas flow detecting means 4 to the flow counter 9 is stopped, and the estimated flow Qe within the unstable flow time Tu is stopped.
Is added to the flow counter 9 as the corrected flow rate Qa, the above-described integrated flow rate Qs is corrected. However, the pulse input gate 9a is shut off so that the flow rate detection signal Sq within the flow rate unstable time Tu is not integrated. The above-mentioned flow rate correction processing may be omitted by setting the estimated flow rate Qe to zero. As a result, it is possible to prevent the gas consumer from being charged an excessive gas usage fee.

<9> In the above-described embodiment, the predetermined time at which the integrated flow rate is corrected is determined by closing the shut-off valve 2 arranged on the inlet side of the measurement flow path 1 and closing the gas in the downstream flow path. When detecting a leak, the flow rate detection signal Sq
Has been described as being set to a time zone in which the flow rate is not oscillated, but the predetermined time point for correcting the integrated flow rate may be any time point during the flow rate measurement. For example, while the correction flow rate Qa stored in the correction register 7 is decremented or incremented, the incremented or decremented value of the integrated flow rate accumulated in the flow counter 9 is maintained, and the corrected flow rate Qa always approaches zero. It can also be processed as follows.

[0044]

As described above, according to the present invention,
Even if there is an unstable flow rate in the process of integrating the gas flow rate in the gas meter, it is possible to prevent the integrated flow rate from becoming excessive.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of an example of a gas meter according to the present invention.

FIG. 2 is a system diagram illustrating an example of signal processing according to the present invention.

FIG. 3 is a diagram illustrating an example of flow rate correction according to the present invention.

FIG. 4 is a conceptual diagram showing another example of the gas meter according to the present invention.

FIG. 5 is a system diagram illustrating another example of signal processing according to the present invention.

FIG. 6 is a conceptual configuration diagram illustrating another example of signal processing according to the present invention.

FIG. 7 is a diagram illustrating another example of flow rate correction according to the present invention.

FIG. 8 is a conceptual diagram illustrating another example of signal processing according to the present invention.

FIG. 9 is a conceptual diagram illustrating an example of a conventional gas meter.

FIG. 10 is a diagram showing an example of a characteristic of a gas flow detecting means;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measurement flow path 1A Main flow path 1B Sub flow path 2 Shut-off valve 4 Gas flow detection means 9 Flow counter Sq Flow detection signal Sa Correction input signal L Calibration curve Tu Flow unstable time Qr Actual measurement flow Qa Correction flow Qe Estimated flow q Short time Flow detection value

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Hiroshi Matsushita Hiroshi Matsuno, 1-2-1, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Shuichi Okada 4-chome, Hirano-cho, Chuo-ku, Osaka-shi, Osaka No. 1-2 F-term in Osaka Gas Co., Ltd. (reference) 2F030 CA04 CC13 CD20 CE25 CF05 CF11

Claims (6)

[Claims] A gas flow detecting means is provided in a measuring flow path, a flow counter for integrating a flow rate based on a flow detection signal from the gas flow detecting means is provided, and a shutoff valve is provided at an inlet side of the measuring flow path. In the gas meter arranged and configured to be capable of opening and closing the shut-off valve during the flow rate measurement, the flow rate unstable time set to a specific time length starting from the time of the opening and closing operation of the shut-off valve, A signal of a gas meter for setting a correction flow rate for the actually measured flow rate within the flow rate unstable time and using the corrected flow rate at a predetermined time after the flow rate unstable time has elapsed to correct the integrated flow rate integrated in the flow counter. Processing method. 2. An estimated flow rate within the unstable flow rate time is obtained based on the measured flow rate before, after or before or after the unstable flow rate time, and the measured flow rate within the unstable flow rate time matches the estimated flow rate. The signal processing method for a gas meter according to claim 1, wherein the correction flow rate is set to perform the correction. 3. The measurement flow path is provided in parallel with the main flow path in which the gas flow rate detection means is arranged and the main flow path without the gas flow rate detection means. Path resistance is configured with at least one sub-flow path set to a specific ratio, comprising a shut-off valve on the inlet side of the measurement flow path, and opening and closing the cut-off valve provided in the sub-flow path during flow measurement The gas flow rate of the gas flow rate detecting means is configured to be changeable by operating the gas flow rate using a gas meter having a flow rate counter that integrates the flow rate based on the flow rate detection signal from the gas flow rate detecting means. To measure, for the flow unstable time set to a specific time length from the time of opening and closing operation of the shut-off valve provided in the sub-flow path, the actual measured flow before or after or before or after the flow unstable time Based on the flow It asked the estimated flow rate in the unstable time,
A signal processing method for a gas meter, wherein after the elapse of the unstable flow rate time, the integrated flow rate integrated in the flow counter is corrected by a corrected flow rate set so that an actually measured flow rate within the unstable flow rate time matches the estimated flow rate. 4. The integrated flow rate is corrected by stopping inputting the flow rate detection signal to the flow rate counter during the flow rate unstable time and adding the estimated flow rate as the correction flow rate. 3. The signal processing method for a gas meter according to claim 1. 5. A predetermined time point for correcting the integrated flow rate,
The shutoff valve disposed on the inlet side of the measurement flow path is closed, and the time is set to a time period in which the flow rate detection signal is not oscillated from the gas flow rate detection means. Signal processing method for gas meters. 6. A gas meter having a gas flow detecting means disposed in a measurement flow path and a flow counter for integrating a flow rate based on a flow detection signal from the gas flow detecting means, wherein the calibration of the gas flow detecting means is performed. Find the curve in advance,
The short-time flow rate detection value of the gas flow rate detecting means is compared with the calibration curve, and a correction input signal is added to the input signal to the flow counter based on the comparison result based on the comparison result with the calibration curve. A signal processing method of a gas meter for correcting an integrated flow rate integrated in the flow counter.