JP2001165740A - Flow rate measurement device and electronic gas meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow rate measurement device capable of reducing power consumption without lowering flow rate measurement accuracy. SOLUTION: An instantaneous measurement means 100 can choose any one of the first mode for measuring instantaneous flow rate by measuring physical quantities varying with the gas flow velocity in gas flow at every certain period and multiplying the measured physical quantities and the cross sectional area of the gas flow path and the second mode for measuring the instantaneous flow rate by measuring physical quantities intermittently for specific times at a certain interval and multiplying the average of the measured physical quantities of specific times and the cross sectional area of the gas flow path. A pass flow rate measuring means 14a-1 measures the pass flow rate of the passed gas by multiplying the instantaneous flow rate measured with the instantaneous flow rate measurement means 100 and the certain period according to the measurement mode set by the measurement mode setting means 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate measuring device and an electronic gas meter, and more particularly, to a flow rate measuring device for measuring a flow rate of a fluid such as a gas, and an integrated gas flow rate measured by the device. It relates to an electronic gas meter.

[0002]

2. Description of the Related Art Conventionally, as this type of flow measuring device, there is an ultrasonic flow measuring device using an ultrasonic sensor, for example. The ultrasonic flow rate measuring device comprises a flow sensor composed of two acoustic transducers, for example, a piezoelectric vibrator operating at an ultrasonic frequency arranged at a fixed distance in a gas flow path, and generating one of the transducers. The other transducers alternately receive the ultrasonic signal to be transmitted, and intermittently measure the physical quantity consisting of the time during which the ultrasonic signal propagates between the transducers in the gas flow direction and in the direction opposite to the gas flow direction. The intermittent calculation of the flow velocity of the gas flowing in the gas flow path based on the two measured propagation times, and the calculation processing of obtaining the instantaneous flow rate by multiplying the flow velocity by the cross-sectional area of the gas flow path. Has become. An electronic gas meter can be configured by multiplying the instantaneous flow rate by the intermittent time to obtain a flow rate and displaying the integrated flow rate obtained by integrating the flow rates.

[0003]

Some combustors that consume gas supplied through an electronic gas meter cause pressure fluctuations in the supplied gas pressure during use. For example, in the case of a GHP (gas heat pump), the use thereof causes a change in gas pressure of about 15 mmH ₂ O by 10 mm.
It occurs at a frequency of 〜20 Hz. Such a GHP is a pulsating flow source that generates a pulsating flow in the gas flow path, and when installed and used in a specific consuming house in an apartment house or the like, an electronic gas meter of a neighboring house is generated due to pressure fluctuations caused by the GHP. Since an instantaneous gas flow occurs in the gas flow path inside, a time difference corresponding to a certain flow rate is measured. If this is mistaken for the gas flow rate accompanying gas consumption and the integrated flow rate is calculated as the passing flow rate, the integrated value will be larger than the actual gas consumption, which is fatal for a measuring instrument. This is a reliability issue.

[0004] That is, when a pressure fluctuation occurs in the electronic gas meter as shown in FIG. 8A in a state where no gas is consumed, the gas in the gas flow path is moved upstream and downstream due to the influence of the pressure fluctuation. As a result, the passing flow rate has a pulsation of 10 to 20 Hz as shown in FIG. If intermittent measurements were taken in response to this,
The passing flow rate as shown in FIG. 8C is obtained, and the passing flow rate Ta measured at the timing A is integrated even when no gas is used.

Further, when the above-mentioned pressure fluctuation occurs on the upstream side of the electronic gas meter of a consumer house consuming gas, the flow rate in the gas flow path of the consumer house repeatedly increases and decreases. When an electronic gas meter is used to determine a passing flow rate that repeats such an increase and decrease, as in recent years, a gas leak detection function and a security function such as a gas leak alarm function and a gas supply cut-off function linked to the gas leak detection function are electronically operated. When mounted on a gas meter, the following problems occur.

That is, although the gas flow rate does not actually exceed the gas leakage determination level, the flow rate exceeding the gas leakage determination level is obtained by the electronic gas meter from the relationship of the measurement timing, and the gas leakage warning and supply gas are obtained. Even if the cut-off is performed erroneously, or conversely, despite the fact that it actually exceeds the gas leak determination level, the passage flow rate below the gas leak determination level is determined by the electronic gas meter from the relationship of the measurement timing, A problem arises in that the execution of the gas leak alarm and the supply cutoff is delayed.

Therefore, there are the following electronic gas meters incorporating a flow rate measuring device for solving the above-mentioned problems. That is, as shown in FIG. 4B, the physical quantity according to the flow velocity is intermittently measured, for example, four times for each predetermined period Ts1, and the average value of the physical quantities measured four times is multiplied by the cross-sectional area of the gas flow path. This measures the instantaneous flow rate. Then, the gas passing flow rate is measured by multiplying the measured instantaneous flow rate by the certain period Ts1. As described above, by taking the average value of the gas flow rates measured four times, even if the gas flow rate fluctuates due to the pulsating flow, the increase / decrease is offset and the accurate instantaneous flow rate can be measured.

The period of the pulsating flow is 50 msec to 100 msec.
, The intermittent time Ts2 is half of 50 msec.
It must be set to 5 msec or less. As described above, by setting the intermittent time Ts2 to be equal to or less than half of the minimum pulsating flow cycle 50 msec, for example, the vicinity of the maximum value of the pulsating flow, that is, the peak portion of the pulsating flow is repeatedly sampled, And the valley portion of the pulsating flow is repeatedly sampled, and the averaging calculated passing flow rate does not become smaller than the actual passing flow rate.

In the electronic gas meter that takes the above-mentioned average value, when the flow rate is measured in a gas flow path in which a pulsating flow is generated, the flow rate measurement accuracy is improved as compared with the above-described conventional case. However, if this electronic gas meter is installed in a gas flow path where no pulsating flow occurs, the instantaneous flow rate can be obtained by a single measurement in the past, despite the fact that the flow rate measurement accuracy is almost the same as the above-mentioned conventional one. Is measured several times, an instantaneous flow rate cannot be obtained, so that a larger power consumption is required than in the above-described conventional case. In other words, useless power consumption is generated by measurement of useless physical quantities that do not lead to improvement in flow rate measurement accuracy. Therefore, the above-mentioned conventional electronic gas meter may be installed in a gas flow path in which no GHP is installed in a house or a neighbor and a pulsating flow is not generated. However, if the GHP is installed thereafter, the flow rate measurement accuracy decreases. Resulting in. In addition, even if the GHP is installed in one's own or a neighboring house,
For example, a GHP for heating is not used in a season other than winter, and in a season when the GHP is not used, wasteful power consumption is generated due to measurement of a wasteful physical quantity which does not lead to improvement in flow rate measurement accuracy as described above.

Accordingly, the present invention provides a flow rate measuring apparatus which focuses on the above problems and reduces power consumption by reducing wasteful power consumption without lowering flow rate measurement accuracy. The task is to

The present invention also provides an electronic gas meter capable of reducing the useless power consumption, thereby reducing the error in the passing flow rate and accurately integrating and displaying the gas usage even if the power consumption is reduced. The task is to provide

[0012]

According to the first aspect of the present invention, which has been made to solve the above-mentioned problems, as shown in the basic configuration diagram of FIG. 1, the ratio varies according to the flow rate of the gas in the gas flow path. A first measurement mode in which a physical quantity is measured at regular intervals, and the measured physical quantity is multiplied by a cross-sectional area of the gas flow path to measure an instantaneous flow rate; An instantaneous flow rate that can be selected from any of the second measurement modes for measuring the instantaneous flow rate by measuring and multiplying the average value of the physical quantities measured the predetermined number of times by the cross-sectional area of the gas flow path. Measuring means 100
And the first measurement mode and the second measurement mode,
Measurement mode setting means 16 for selecting and setting one of them
And a flow rate measurement for measuring a flow rate of the gas passing through the gas flow path by multiplying the constant flow rate by the instantaneous flow rate measured by the instantaneous flow rate measurement means in the measurement mode set by the measurement mode setting means. Means 14a-
1) and a flow rate measuring device characterized in that

According to the first aspect of the present invention, the instantaneous flow rate measuring means 100 measures a physical quantity that changes in accordance with the flow rate of the gas in the gas flow rate at regular intervals, and measures the measured physical quantity and the gas flow path. A first measurement mode in which the instantaneous flow rate is measured by multiplying by a cross-sectional area, and a physical quantity is measured intermittently a predetermined number of times at regular intervals, and the average value of the physical quantity measured a predetermined number of times and the cross-sectional area of the gas flow path are calculated. Either of the second measurement modes for measuring the instantaneous flow rate by multiplying the flow rate can be selected, and the passing flow rate measurement means 14a-1 is used.
Measures the passing flow rate of the gas that has passed by multiplying the instantaneous flow rate measured by the instantaneous flow rate measuring means 100 in the measurement mode set by the measurement mode setting means 16 by a certain period.

The measurement of the instantaneous flow rate in the second measurement mode requires measuring the physical quantity a predetermined number of times, so that the instantaneous flow rate is determined based on the physical quantity obtained by one measurement. However, when the gas flow rate fluctuates by taking the average value of the physical quantity measured a predetermined number of times, the fluctuation can be canceled out, and the instantaneous flow rate of the gas flow path in which the pulsating flow occurs is obtained. Is valid. Further, when there is no pulsating flow, it is not necessary to cancel the fluctuation due to the pulsating flow, so that even if the instantaneous flow rate is measured in the first measurement mode with low power consumption, the flow rate measurement accuracy does not decrease.

Therefore, if it is known in advance that a gas heat pump or the like serving as a pulsating flow source is installed in a house or a neighboring house, the pulsating flow can be set by setting the second measuring mode by the measuring mode setting means 16. Does not decrease even when the flow rate is generated. If it is known in advance that a gas heat pump or the like serving as a pulsating flow source is not installed in a house or a neighbor, if the first measuring mode is set by the measuring mode setting means 16, the flow rate of the pulsating flow can be reduced. In spite of no fluctuation, a large amount of power is consumed in the second measurement mode to obtain the instantaneous flow rate, and the instantaneous flow rate can be accurately measured while suppressing the power in the first measurement mode. No wasted power is consumed.

According to a second aspect of the present invention, when the first measurement mode is set by the measurement mode setting means, the instantaneous flow rate measurement means measures the physical quantity for each of the predetermined periods, and When the second measurement mode is set, the measuring means 100a intermittently measures the physical quantity a predetermined number of times during the fixed period, and when the second measuring mode is set, the physical quantity is measured a predetermined number of times by the measuring means. And an average value calculating means 14a-2 for calculating an average value each time is measured, and when the first measurement mode is set, the physical quantity measured by the measuring means and the gas flow path are measured. The instantaneous flow rate is measured by multiplying the cross-sectional area, and when the second measurement mode is set, the instantaneous flow rate is multiplied by the average value calculated by the average value calculating means and the cross-sectional area of the gas flow path. Lies in the flow rate measuring apparatus according to claim 1, wherein the measuring the amount.

According to the second aspect of the present invention, in the instantaneous flow rate measuring means 100, when the measuring means 100a sets the first measuring mode by the measuring mode setting means 16, the physical quantity is measured at regular intervals, and When the second measurement mode is set, the physical quantity is measured intermittently a predetermined number of times at regular intervals, and when the average value calculation means 14a-2 is set to the second measurement mode, the measurement means 100a
The average value is calculated each time the physical quantity is measured a predetermined number of times, and when the first measurement mode is set, the measuring means 10
0a is multiplied by the cross-sectional area of the gas flow path to measure the instantaneous flow rate. When the second measurement mode is set, the average value calculated by the average value calculation means 14a-2 and the gas flow rate are measured. The instantaneous flow rate is measured by multiplying the cross-sectional area of the road.

Therefore, if it is known in advance that a gas heat pump or the like as a pulsating flow source is installed in a house or a neighbor, the pulsating flow can be set by setting the second measuring mode by the measuring mode setting means 16. Does not decrease even when the flow rate is generated. If it is known in advance that a gas heat pump or the like serving as a pulsating flow source is not installed in a house or a neighbor, if the first measuring mode is set by the measuring mode setting means 16, the flow rate of the pulsating flow can be reduced. In spite of no fluctuation, a large amount of power is consumed in the second measurement mode to obtain the instantaneous flow rate, and the instantaneous flow rate can be accurately measured while suppressing the power in the first measurement mode. No wasted power is consumed.

The invention according to claim 3 further includes a fluctuation cycle setting means 17 for presetting a fluctuation cycle of the flow rate, wherein the instantaneous flow rate measuring means sets the fluctuation cycle when the second measurement mode is set. The flow rate measuring device according to claim 1 or 2, wherein the physical quantity is measured the predetermined number of times at each intermittent time according to the flow rate fluctuation cycle set by the setting means.

According to the third aspect of the present invention, when the second measurement mode is set, the instantaneous flow rate measuring means 100 sets the physical quantity for each intermittent time corresponding to the flow rate fluctuation cycle set by the fluctuation cycle setting means 17. Is measured a predetermined number of times. Incidentally, since the fluctuation of the flow rate occurs in synchronization with the rotation of the gas heat pump, the fluctuation cycle is determined by the rotation cycle of the gas heat pump. Therefore, when the rotation cycle of the gas heat pump is known in advance, the flow rate variation cycle determined by the cycle is set by the variation cycle setting means 17,
If the physical quantity is measured at every intermittent time according to the fluctuation cycle set by the fluctuation cycle setting means 17, the peak and the valley of the flow fluctuation can be measured. Offset.

According to a fourth aspect of the present invention, the variable period setting means presets the variable frequency based on a variable frequency signal transmitted from outside via a communication circuit. In the flow measurement device.

According to the fourth aspect of the present invention, the fluctuation cycle setting means 17 presets the fluctuation frequency based on the fluctuation frequency signal transmitted from the outside via the communication line.
The fluctuation period can be set within a gas company or management company that knows the usage status of the gas heat pump, that is, by remote control from outside.

According to a fifth aspect of the present invention, the measurement mode setting means sets the measurement mode based on a measurement mode signal transmitted from outside via a communication line. The present invention resides in any one of the flow rate measuring devices described above.

According to the fifth aspect of the present invention, since the measurement mode setting means 17 sets the measurement mode based on the measurement mode signal transmitted from the outside via the communication line, the use state of the gas heat pump is grasped. The measurement mode can be set within a gas company or management company that is operating, that is, by remote control from outside.

According to a sixth aspect of the present invention, there is provided a flow rate measuring device according to any one of the first to fifth aspects, and a flow rate integrating means for integrating a flow rate measured by the flow rate measuring means.
-3, and a display means 15 for displaying the passing flow rate integrated by the passing flow rate integrating means.

According to the sixth aspect of the present invention, the flow rate integrating means integrates the gas flow rate measured by the flow rate measuring device of the first to fourth aspects, and the display means 15 calculates the integrated flow rate integrated by the flow rate integrating means. Accumulate and display the accurate passing flow rate measured by the flow rate measuring device, which can further reduce power consumption by reducing wasteful power consumption without reducing the flow rate measurement accuracy. Can be.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an electronic gas meter incorporating the flow rate measuring device of the present invention. The illustrated electronic gas meter is configured as an ultrasonic type, and a gas flow path 10 as a flow path in the gas meter for flowing a gas as a fluid.
Two acoustic transducers TD1 and T2, for example consisting of piezoelectric transducers, which are arranged at a distance L in the direction of gas flow and which operate at ultrasonic frequencies arranged opposite one another
D2. The gas flow path 10 is provided with a shutoff valve 10c that shuts off the gas flow path 10 by closing the valve upstream of the two acoustic transducers TD1 and TD2.

Each of the transducers TD1 and TD2 is connected to a transmitting circuit 12 and a receiving circuit 1 via transducer interface (I / F) circuits 11a and 11b, respectively.
3 is connected. The transmission circuit 12 transmits a signal for generating an ultrasonic signal by driving one of the transducers TD1 and TD2 under the control of a microcomputer (μCOM) 14 in the form of a pulse burst. (Not shown). The receiving circuit 13
A preamplifier (not shown) for processing the ultrasonic signals by inputting the signals from the other transducers TD1 and TD2 which have received the ultrasonic signals passing through the gas flow path 10 is built in.

As shown in FIG. 3, the above-mentioned μCOM 14 is a read-only memory (RO) storing a central processing unit (CPU) 14a for performing various processes according to programs and a program for the processes performed by the CPU 14a.
M14b, RA which is a readable and writable memory having a work area used in various processing steps in the CPU 14a, a data storage area for storing various data, and the like.
M14c, etc., which are interconnected by a bus line 14d.

The CPU 14a in the μCOM includes a transmitting circuit 1
2 and a receiving circuit 13 for supplying a signal from
The transmission of the ultrasonic signal alternately transmitted and received between the two transducers that changes according to the flow velocity of the gas flowing in the gas flow path 10 is controlled while alternately switching between the transducer that receives the ultrasonic signal and the transducer that receives the ultrasonic signal. A measurement process of measuring a time difference as a physical quantity that changes according to the gas flow velocity in the gas flow path 10 is performed.

A connection point between the resistor R1 connected to the battery B and the measurement mode setting switch SW connected to the ground is connected to the μCOM 14. The measurement mode setting switch SW is used by a gas company or a management company as a user to select and set one of two measurement modes described later. That is, as shown in the timing of the measurement processing in FIG.
A first measurement mode in which the instantaneous flow rate is measured by multiplying the difference between the propagation times measured by the measurement processing of 14a and the cross-sectional area of the gas flow path 10, (FIG. 4A), and a certain period Ts
Each time, a predetermined number of times are measured at intervals of the intermittent time Ts2 (hereinafter, described as the predetermined number = 4 times). The average value of the difference of the propagation times measured four times is multiplied by the cross-sectional area of the gas flow path 10. And a second measurement mode (FIG. 4 (b)) for measuring the instantaneous flow rate according to FIG.

In the above-described measurement of the instantaneous flow rate in the second measurement mode, the measurement processing must be performed four times, and therefore, the first measurement of the instantaneous flow rate based on the difference in the propagation time obtained by one measurement processing is performed. However, when the gas flow rate fluctuates by taking the average value of the differences in the propagation times measured four times, the fluctuation can be canceled out and the pulsating gas This is effective for obtaining the instantaneous flow rate of the flow path 10. In addition, when the pulsating flow is not generated, the fluctuation due to the pulsating flow does not need to be canceled, so that even if the instantaneous flow rate is measured in the first measurement mode with low power consumption, the flow rate measuring accuracy does not decrease.

That is, when it is known that the GHP is not installed in a house or a neighboring house or that the GHP is not used for a long period of time, the first measurement mode is changed to the state where the GHP is installed or in use. If it is known in advance, the second measurement mode is selected and set. If the gas flow rate is not increased or decreased due to the pulsating flow, the second measurement mode consumes unnecessarily large electric power and the instantaneous flow rate is increased. And the instantaneous flow rate can be accurately measured while suppressing power in the first measurement mode, so that wasteful power is not consumed.

The measurement mode setting switch SW is turned on and off in conjunction with the operation of a measurement mode setting button 16 as the measurement mode setting means 16 shown on the operation panel of the electronic gas meter in FIG. Then, the CPU 14a
By operating the measurement mode setting button 16, the measurement mode setting switch SW is turned on, and the measurement mode setting switch S
When the connection point between W and the resistor R1 reaches the ground potential, the instantaneous flow rate measurement process in the first measurement mode is executed, while the measurement mode setting switch SW is turned off, and the measurement mode setting switch SW and the resistor R1 are connected. When the connection point becomes the battery potential, the instantaneous flow rate measurement processing in the second measurement mode is executed.

By the way, when the instantaneous flow rate measurement processing is performed in the second measurement mode, the intermittent time T
If s2 is less than 1/2 of the fluctuation period of the gas flow, the peak and the valley of the flow fluctuation can be measured, and if the average value measured four times is taken, the fluctuation will be surely canceled and the flow measurement accuracy will be improved. can do. Therefore, as shown in FIG. 5, on the operation panel surface of the electronic gas meter, in addition to the above-described measurement mode setting button 16, an adjustment knob 17 is provided as a fluctuation cycle setting means for presetting the fluctuation cycle of the gas due to the pulsating flow.
The fluctuation cycle set by the adjustment knob 17 is displayed on the display 15 (display means). Further, as shown in FIG. 2, there is provided a variable resistor Ra whose resistance value changes in accordance with a fluctuation cycle set by operating the adjustment knob 17,
The CPU 14a performs the measurement process four times at intervals of the intermittent time Ts2 according to the resistance value of the variable resistor Ra.

The GHP is previously set to, for example, two-cylinder 800
If it is known that the motor rotates at a speed of 150 rpm, the cycle is 150 msec (= 60 m) in synchronization with the rotation of the GHP.
(Second) / 800 (rpm) / 2 * 100) occurs, so if the variable resistor Ra is adjusted by operating the adjustment knob 17 so that the display 15 indicates 75 msec,
The CPU 14a operates for 75 msec in accordance with the value of the variable resistor Ra.
For example, since the instantaneous flow rate measurement process in the second measurement mode is performed by setting the intermittent time Ts2 to 1/4 of the gas flow rate fluctuation cycle,
Since it can be set to 2 or less, the flow rate measurement speed can be improved.

The CPU 14a in the μCOM 14 further includes:
Acts as a passing flow rate measuring means, and sets the instantaneous flow rate corresponding to the gas flow velocity measured by the instantaneous flow rate measurement processing to a predetermined period Ts.
By multiplying by 1, the flow rate measurement processing for obtaining the flow rate of the gas flowing through the gas flow path 10 is performed.

The CPU 14a in the μCOM 14 functions as a passing flow rate integrating means in addition to the above-described processing, integrates the passing flow rate obtained by the passing flow rate measuring processing to obtain an integrated flow rate, and calculates the integrated flow rate. Display processing for displaying the integrated flow rate value on the display unit 15 when the gas flow rate in the gas flow path 10 exceeds a predetermined total flow rate value (preset by summing the consumption flow rates of the connected combustors). It is determined that abnormal gas other than the gas flow rate consumed by the combustion equipment is flowing through the gas flow path 10 due to the disconnection of the gas hose, and the shutoff valve 10c provided in the gas flow path 10 is closed to close the gas flow path. For example, a total flow rate cutoff process to be cut off is performed.

The detailed operation of the electronic gas meter incorporating the above-described flow measuring device will be described below with reference to the flowchart of FIG. 6 which describes the processing procedure of the CPU 14a of the μCOM 14. The CPU 14a starts the operation by turning on the battery power, for example, and performs initial settings of various areas formed in the RAM 14c in the μCOM 14 in an initial step (not shown), and then proceeds to the first step S1. The measurement mode setting switch SW is turned off by the operation of the measurement mode setting button 16 by the user, and if the first measurement mode is set, the determination in step S1 is NO and the process proceeds to step S2.

Specifically, in step S2, as shown in FIG. 7 (a), in step S2a, an ultrasonic signal is transmitted from the acoustic transducer TD1 until the transmitted ultrasonic signal reaches the acoustic transducer TD2. The time taken is measured as a propagation time T1. Subsequently, the process proceeds to step SP2b, where an ultrasonic signal is transmitted from the acoustic transducer TD2, and a time required for the transmitted ultrasonic signal to reach the acoustic transducer TD1 is measured as a propagation time T2.

Thereafter, the process proceeds to step S2c, in which the difference between the propagation time T1 measured in step S2a and the propagation time T2 measured in step S2b is calculated and stored in the time area Td. Thereafter, the process proceeds to step S2d, where the time area T
The flow velocity v is obtained by multiplying d by a value of a predetermined coefficient K,
This is stored in the flow velocity area formed in the RAM 14c, and the instantaneous flow rate Qi can be obtained by multiplying the flow velocity v by the cross-sectional area S of the gas flow path 10. In the subsequent step S2e, the count area Ts
The elapsed time α from step S2a to step S2e is set to 1 ′, and the process proceeds to step SP4 in FIG. 6 described below.

On the other hand, if the user operates the measurement mode setting button 16 to turn on the measurement mode setting switch SW, and if the second measurement mode is set, step S is executed.
The determination of 1 is YES, and the process proceeds to step S3. Specifically, in step SP3, as shown in FIG. 7B, first, in step S3a, the resistance value of the variable resistor Ra is read, the intermittent time Ts2 corresponding to the read resistance value is determined, and the process proceeds to step S3b. move on. Step S3a, 3
In b, the propagation times T1 and T2 are measured in the same manner as in steps S2a and S2b, and the flow advances to step S3d.

In the subsequent step S3d, the measurement count area n is incremented. In the subsequent step S3e, a difference between the propagation time T1 measured in step S3b and the propagation time T2 measured in step S3c is obtained, and the difference is stored in a time area Tdn corresponding to the measurement count area n incremented in step S3d. . That is, when the instantaneous flow rate measurement process in the second measurement mode is started, the first measurement of T1 and T2 is performed, and if the measurement count count area n = 1, the difference is recorded in the time area Td1 and the second time T1 and T2. If it is the measurement of T2 and the number of times of measurement n = 2, the difference is taken as the time area Td2
, And the process proceeds to step S3f. In step SP2f, the intermittent time count area Ts2 'stored in the RAM 14c is incremented. Next, the process proceeds to step S3g and proceeds to step S3f.
The intermittent time count area Ts2 'incremented by
Is longer than the intermittent time Ts2 determined in step S3a.

If the intermittent time count area Ts2 'does not exceed the intermittent time Ts2, that is, if the intermittent time Ts2 has not elapsed since the difference Tdn was obtained in step S3f, the process returns to step S3f, and the intermittent time count area T
The increment of s2 'is repeated. Step S3
At f, the increment of the intermittent time count area Ts2 'is repeated, and as a result, the intermittent time count area Ts2' exceeds the intermittent time Ts2 determined in step S3a, that is, the intermittent time Ts2 has elapsed since the difference Tdn was obtained in step S3e. Then, the determination in step S3g becomes YES, the intermittent time counter area Ts2 'is reset in step S3h, and the process proceeds to step S3i.

In step S3i, it is determined whether or not the number-of-measures count area n incremented in step S3d exceeds a predetermined number, for example, four, that is, the difference Td for each intermittent time Ts2 is measured four times. It is determined whether or not it has been performed. Difference T for each intermittent time Ts2
When the measurement of d is not performed four times, the determination in step S3i is always NO, and the process returns to step S3b again. Therefore, when the number of times of measurement is four or less, the measurement of the difference Tdn at intervals of the intermittent time Ts2 is repeatedly performed. Then, when the measurement of the difference Td for each intermittent time Ts2 is repeated four times, the determination in step S3i becomes YES and the step S3i becomes YES.
Proceed to 3j. In step S3j, it works as an average value calculating means, and calculates the average value Tdave = (Td1 +...) From the time areas Td1, Td2,.
+ Tdn) / n is calculated and stored in the average area Tdave before proceeding to step S3k.

In step S3k, a flow velocity v is obtained by multiplying the average area Tdave by a predetermined coefficient K, and the obtained flow velocity v is calculated in the flow velocity area v formed in the RAM 14c.
And the instantaneous flow rate Qi can be obtained by multiplying the flow velocity v by the cross-sectional area S of the gas flow path 10. Then, in the subsequent step S31, the measurement count area n is reset, and the intermittent time Ts2 * 4, which is the elapsed time from the start of the instantaneous flow rate measurement process in the second measurement mode to step S31, is counted area Ts1 'for a fixed period. And proceeds to step SP4 in FIG. 6 described later.

In step SP4 of FIG. 6, the count area Ts1 'is incremented for a certain period. In step SP5, it is determined whether or not the count area Ts1' has exceeded a predetermined period Ts1.
That is, it is determined whether or not a fixed period Ts1 has elapsed since the start of the instantaneous flow rate measurement processing in step S2 or step S3. While the fixed period Ts1 has not elapsed, the process returns to step S4, and the increment of the count area Ts1 ′ for the fixed period is repeated. Count area Ts for a certain period
As a result of repeating the increment of 1 ', if the count area Ts1' exceeds the fixed period Ts1 for a certain period, the determination in step SP5 becomes YES and the process proceeds to step SP6.

In step SP6, after resetting the count area Ts1 'for a certain period, the process proceeds to the subsequent step SP7. In step SP7, the instantaneous flow rate Qi obtained in step S2 or 3 and the predetermined period T
s1 to obtain a passing flow rate Qt.
It is stored in the passing flow rate area Qt in c. Thereafter, the process proceeds to step SP8, where the flow rate Qt obtained in step SP7 is added to the flow rate accumulation area Q in the RAM 14c, and then, in step SP9, the content of the flow rate accumulation area Q is displayed on the display 15 and the process proceeds to step SP10. .

In step SP10, when the passing flow rate Qt obtained in step SP7 exceeds a predetermined total flow rate value, that is, when the consumption flow rates of the combustors connected via the gas flow path 10 are summed up, a predetermined value is set. If the passing flow rate Qt exceeds the total flow rate value determined, it is determined that abnormal gas other than the gas flow rate consumed by the combustion equipment is flowing through the gas flow path 10 due to the gas hose being disconnected, and the determination is Y.
It becomes ES and proceeds to step SP11. Then, in step S11, a total flow rate cutoff process is performed in which the shutoff valve 10c provided in the gas flow path 10 is closed to shut off the gas flow path 10. Thereafter, when a return operation of an operation switch (not shown) is performed, the determination in step S12 becomes YES and the process returns to step S1. On the other hand, the passing flow rate Qt obtained in step S7
If does not exceed the total flow value, step SP10
Is NO, and the process immediately returns to step S1.

In the above-described embodiment, the measurement mode setting button 16 provided on the operation panel of the electronic gas meter is used.
Thereby, of the first measurement mode and the second measurement mode,
Although one of them is selected and set, for example, the measurement mode may be set via a communication line by remote control from a gas company or a management company. In this case, an employee of the gas company or the management company does not have to go to the place where the flow rate measuring device is installed, and the cost can be reduced.

Similarly, the fluctuation cycle set in advance by the adjustment knob 17 provided on the operation panel of the electronic gas meter can be similarly set via a communication line by remote control from a gas company or a management company. Is also good.

In the above-described embodiment, the measurement mode setting button 16 and the adjustment knob 17 are provided separately. However, for example, when the adjustment knob 17 is turned to the right, the first
If the measurement mode is set to any other position and
The measurement may be performed a predetermined number of times in the intermittent time Ts2 according to the operation amount of the adjustment knob 17 set in the measurement mode. In this case, it is not necessary to separately provide the measurement mode setting button 16 and the adjustment knob 17, and the cost can be reduced.

Further, in the above-described embodiment, the measurement mode setting button 16 is provided as the measurement mode setting means. For example, the return for opening the shutoff valve 10c which has been closed by shutting off the total flow rate or the usage time is performed. The measurement mode may be set by turning on / off the valve return button on which the operation is performed. That is, when the shut-off valve 10c is not closed, the first measurement mode or the second measurement mode is set by the valve reset button (for example, the first measurement mode is set when the reset operation button is turned on, and the first measurement mode is set when the reset operation button is turned off. The second measurement mode is set.) When the shut-off valve 10c is closed, the shut-off valve 10c is operated by returning the valve return button from ON to OFF or from OFF to ON.
c is opened. With this configuration, it is not necessary to provide the measurement mode setting button 16 separately from the valve return button, and the cost can be reduced.

[0054]

As described above, according to the first or second aspect of the present invention, even though there is no fluctuation in the flow rate due to the pulsating flow, the second measuring mode consumes a large amount of electric power and the instantaneous flow rate is reduced. Since the instantaneous flow rate can be accurately measured while suppressing the power in the first measurement mode, unnecessary power is not consumed. Therefore, the flow rate measurement accuracy is not reduced. A flow measurement device capable of reducing power consumption can be obtained.

According to the third aspect of the invention, when the rotation cycle of the gas heat pump is known in advance, the flow rate variation cycle determined by the cycle is set by the variation cycle setting means, and set by the variation cycle setting means. If the physical quantity is measured for each intermittent time according to the fluctuation cycle, the peak and valley of the flow fluctuation can be measured, and if the average value measured a predetermined number of times is taken, the fluctuation is surely canceled out, so that A flow measurement device with further improved flow measurement accuracy can be obtained.

According to the fourth aspect of the present invention, the measurement mode can be set within a gas company or management company that knows the usage status of the gas heat pump, that is, by external remote control. This eliminates the need for an employee of the management company to go to the place where the flow rate measuring device is installed, and can obtain a flow rate measuring device with reduced cost.

According to the fifth aspect of the present invention, the measurement mode can be set by remote control from within the gas company or management company that is aware of the usage of the gas heat pump, which is an external gas heat pump. An employee of the management company
It is possible to obtain a flow rate measuring device that saves cost by reducing the trouble of going to a place where the flow rate measuring device is installed.

According to the sixth aspect of the present invention, by reducing wasteful power consumption, the flow rate measuring device can further reduce power consumption without lowering the flow rate measurement accuracy. Since the passing flow rate can be integrated and displayed, it is possible to obtain an electronic gas meter capable of accurately integrating and displaying the gas usage amount by reducing the error of the passing flow rate even if the power consumption is reduced. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration diagram of a flow measurement device and an electronic gas meter of the present invention.

FIG. 2 is a view showing an embodiment of an electronic gas meter incorporating the flow rate measuring device of the present invention.

3 is a diagram for explaining details of a microcomputer constituting an electronic gas meter incorporating the flow rate measuring device shown in FIG. 2;

FIG. 4 is a diagram for explaining a first measurement mode and a second measurement mode.

5 is a diagram showing an operation panel surface of an electronic gas meter incorporating the flow rate measuring device of FIG. 2;

FIG. 6 is a diagram showing C constituting the microcomputer shown in FIG. 3;
It is a flowchart which shows the processing procedure of PU.

FIG. 7 is a flowchart illustrating details of an instantaneous flow rate measurement process in a first measurement mode and an instantaneous flow rate measurement process in a second measurement mode in FIG. 6;

FIG. 8 is a diagram for explaining a problem of a conventional flow rate measuring device.

[Explanation of symbols]

Reference Signs List 10 gas flow path 100 instantaneous flow rate measuring means 14a-1 passing flow rate measuring means (CPU) 16 measuring mode setting means (measuring mode setting button) 100a measuring means 14a-2 average value calculating means (CPU) 17 fluctuation cycle setting means (adjustment) Knob) 14a-3 Passing flow rate integrating means (CPU) 15 Display means (display)

Continuing on the front page (72) Inventor Haruhiro Akihiro 23 Minami-Kashima, Futamata-cho, Tenryu-shi, Shizuoka Prefecture Inside Yazaki Keiki Co., Ltd. Inventor Norio Niimura 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture, Japan Matsushita Electric Industrial Co., Ltd. 1006 Kadoma, Kadoma Matsushita Electric Industrial Co., Ltd. DA14 DA22 GA02

Claims (6)

[Claims] 1. A method for measuring a physical quantity that changes according to a gas flow velocity in a gas flow path at regular intervals, and measuring an instantaneous flow rate by multiplying the measured physical quantity by a cross-sectional area of the gas flow path. A second measurement mode of measuring the instantaneous flow rate by intermittently measuring the physical quantity a predetermined number of times at a predetermined measurement period and multiplying the average value of the physical quantity measured a predetermined number of times by the cross-sectional area of the gas flow path; An instantaneous flow rate measuring means capable of selecting one of the measurement modes, and a measurement mode setting means for selecting and setting one of the first measurement mode and the second measurement mode Multiplying the instantaneous flow rate measured by the instantaneous flow rate measuring means in the measurement mode set by the measurement mode setting means and the certain period to measure the flow rate of the gas passing through the gas flow path. Flow rate measuring apparatus characterized by comprising a peroxide flow rate measuring means. 2. The instantaneous flow rate measurement means, when the first measurement mode is set by the measurement mode setting means, measures the physical quantity at regular intervals,
A measuring unit for intermittently measuring the physical quantity a predetermined number of times when the second measurement mode is set, and a predetermined number of times by the measuring means when the second measurement mode is set; Average value calculating means for calculating an average value each time a physical quantity is measured, and when the first measurement mode is set, the physical quantity measured by the measuring means and the cross-sectional area of the gas flow path And measuring the instantaneous flow rate by multiplying the average value calculated by the average value calculation means and the cross-sectional area of the gas flow path when the second measurement mode is set. The flow measurement device according to claim 1, wherein: 3. The apparatus according to claim 1, further comprising a fluctuation cycle setting means for setting a fluctuation cycle of the flow rate in advance, wherein said instantaneous flow rate measurement means sets the flow rate set by said fluctuation cycle setting means when said second measurement mode is set. The flow rate measuring device according to claim 1 or 2, wherein the physical quantity is measured the predetermined number of times at each intermittent time according to a fluctuation cycle. 4. The flow rate measuring device according to claim 3, wherein the fluctuation cycle setting means sets the fluctuation frequency in advance based on a fluctuation frequency signal transmitted from the outside via a communication circuit. 5. The measurement mode setting means sets the measurement mode based on a measurement mode signal transmitted from outside via a communication line.
The flow measurement device according to any one of the above. 6. A flow rate measuring device according to claim 1, wherein: a flow rate integrating means for integrating a flow rate measured by said flow rate measuring means; and a flow rate integrated by said flow rate integrating means. And a display means for displaying the following.