JP2004157074A - Flow measuring device and gas meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow rate measuring device capable of grasping a battery residual capacity without being influenced by pulsation. <P>SOLUTION: This device is characterized by being equipped with a power consumption information storage means 1b for storing power consumption information for showing power consumption per prescribed time corresponding to a normal time mode and a pulsation generation time mode, a normal time mode counting means 1a1 for counting the number of times of the prescribed time when a propagation time is extracted by the normal time mode, a pulsation generation time mode counting means 1a2 for counting the number of times of the prescribed time when the propagation time is extracted by the pulsation generation time mode, and a power consumption calculation means 1a3 for calculating the power consumption based on the number of times counted by the normal time mode counting means 1a1, the number of times counted by the pulsation generation time mode counting means 1a2, and the power consumption information stored by the power consumption information storage means 1b. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flow measurement device and a gas meter, and more particularly, to the propagation of the ultrasonic wave at a predetermined time between transducers that transmit or receive ultrasonic waves provided in a gas flow path through which gas flows. The present invention relates to a flow measurement device that extracts time by a different extraction method between a normal mode and a pulsation generation mode, and measures a flow rate of the gas based on the extracted propagation time, and a gas meter including the flow measurement device. It is.
[0002]
[Prior art]
Batteries are widely used when driving loads that are difficult to connect to commercial power, or when driving loads with voltages and currents different from commercial power, and as an example, batteries are installed in each home. There is a gas meter that measures the amount of gas used.
[0003]
In this gas meter, a gas flow meter that measures the flow rate of gas flowing through an internal flow path as a gas usage amount, and gas leakage occurs in a gas supply path based on a measurement result of the flow meter or a time-series change of the measurement result. Gas leak detecting means for determining whether or not the gas leakage has occurred, and a shutoff valve or the like which is driven when the gas leak detecting means determines that gas leakage has occurred and forcibly shuts off the internal flow path. The flow meter, the gas leak detecting means, the shut-off valve and the like are driven by a lithium battery built in the gas meter.
[0004]
In addition, this gas meter has a voltage required for the valve closing operation by the shutoff valve applied to the lithium battery so that the internal flow path is forcibly shut off when the gas leak detection means determines the gas leak. A battery voltage drop inspection device for periodically inspecting whether or not the battery is remaining is provided together with a flow meter, gas leak detection means, a shutoff valve, and the like.
[0005]
In the gas meter described above, when it is determined that the voltage of the lithium battery has decreased to such an extent that the voltage required for the valve closing operation by the shutoff valve is likely to decrease as a result of the inspection by the battery voltage drop inspection device, the presence or absence of gas leakage is determined. Regardless, the shutoff valve is forcibly shut off.
[0006]
For example, a voltage monitoring device disclosed in Patent Document 1 is disclosed. This device includes a control unit for inputting a flow signal of gas or the like from a flow sensor, inputting a drive signal to a base of a transistor for driving a shutoff valve V based on the input signal, and performing an ON operation to perform a forced shutoff control. .
[0007]
Further, the control unit performs a ON / OFF operation by passing a pulse signal at predetermined intervals through a resistor through a base of a transistor in which the positive electrode of the lithium battery is connected to a collector. As a result, a voltage drop occurs in the equivalent resistance of the shut-off valve connected between the emitter of the transistor and the ground. The voltage drop detector monitors the voltage drop of the lithium battery by monitoring the voltage drop at a predetermined monitoring cycle in synchronization with the operation cycle of the transistor.
[0008]
In addition, the battery may temporarily increase in voltage due to temperature characteristics. In order to capture the remaining battery capacity without being affected by such a problem, the present applicant has proposed a voltage monitoring device disclosed in Reference Document 2. I have. This voltage monitoring device counts the power-on time of the battery that maintains the operation of the device, and subtracts the counted power consumption of the battery per normal power-on time from the remaining capacity of the currently used battery to reduce the battery load fluctuation. In addition to the corresponding power consumption, the power consumption of the battery per normal power-on time is subtracted from the remaining capacity of the currently used battery, and it is necessary to accurately monitor the battery voltage drop considering the constant power consumption of the battery. It has been possible.
[0009]
[Patent Document 1]
Japanese Patent Publication No. 4-23169 (page 2, FIG. 1)
[Patent Document 2]
JP-A-2002-40115 (Page 4, FIG. 5)
[0010]
[Problems to be solved by the invention]
However, some of the combustion devices that consume the gas supplied through the gas meter described above cause a pressure fluctuation in the supplied gas pressure during use. For example, in the case of a GHP (gas heat pump), the use of the gas pressure 15mmH to bake ₂ O fluctuations occur at frequencies of 10-20 Hz. Such a GHP is a pulsation source that causes a pulsation in the gas flow path. If the GHP is installed in a specific consumer house in an apartment house or the like, the pressure fluctuation generated by the GHP causes the pulsation in the gas flow path in the gas meter of the neighboring house. Since an instantaneous gas flow occurs, 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.
[0011]
In order to solve such a problem, the gas meter switches the measurement sampling pattern between normal time and pulsation occurrence to prevent a decrease in measurement accuracy at the time of pulsation occurrence. There is a possibility that a difference in power consumption may occur. For this reason, when the gas meter is installed in an environment where pulsation is likely to occur, there is a possibility that a decrease in the battery voltage cannot be accurately determined even by using the above-described voltage monitoring device. In the gas meter, the remaining amount of the battery, which is the driving source, is checked to determine whether the voltage required to drive the shut-off valve has been secured. Need to be eliminated.
[0012]
Therefore, in view of the above-described problems, an object of the present invention is to provide a flow measurement device and a gas meter that can determine the remaining battery capacity without being affected by pulsation.
[0013]
[Means for Solving the Problems]
According to the present invention, there is provided a flow rate measuring apparatus provided in a gas flow path through which a gas flows to transmit or receive an ultrasonic wave, as shown in FIG. The propagation time of the ultrasonic wave at a predetermined time between the wave devices is extracted by a different extraction method between the normal mode and the pulsation generation mode, and the flow rate of the gas is measured based on the extracted propagation time. A power consumption information storage unit 1b for storing power consumption information indicating the power consumption per predetermined time corresponding to the normal mode and the pulsation generation mode; A normal mode counting means 1a1 for counting the number of times of the predetermined time for which the time is extracted, and the predetermined time for which the propagation time is extracted by the pulsation occurrence mode The pulsation occurrence mode counting means 1a2 for counting the number of times, the number of times counted by the normal mode counting means 1a1, the number of times counted by the pulsation occurrence mode counting means 1a2, and the power consumption information storage means 1b are stored. Power consumption calculating means 1a3 for calculating power consumption based on the power consumption information.
[0014]
According to the flow rate measuring device of the present invention, when the propagation time is extracted in the normal mode, the number of times of the predetermined time is counted by the normal mode counting means 1a1. Further, when the propagation time is extracted in the pulsation generation mode, the number of times of the predetermined time is counted by the pulsation generation mode counting means 1a2. The power consumption is calculated based on the number of times counted by the normal mode counting means 1a1, the number of times counted by the pulsation occurrence mode counting means 1a2, and the power consumption information stored in the power consumption information storage means 1b. It is calculated by 1a3. Therefore, power consumption information indicating the power consumption per predetermined time corresponding to the normal mode and the pulsation generation mode is stored, and the predetermined time corresponding to the normal mode and the pulsation generation mode is counted. Power consumed to drive the transducer can be calculated based on the counting result and the power consumption information. Therefore, since the flow rate measuring device calculates the power consumption corresponding to the normal mode and the pulsation generation mode, it is possible to accurately calculate the power consumption even when the pulsation occurs. If the remaining capacity is monitored, the remaining capacity of the battery can be grasped without being affected by the pulsation, so that it is possible to accurately manage the life of the battery and to guarantee the safe operation of the device.
[0015]
In order to solve the above-mentioned problem, the gas meter according to the present invention is provided with a battery 9 as a driving power source, as shown in the basic configuration diagram of FIG. Operation number counting means 1a4 for counting the number of times that the device is operated in a predetermined state and the load of the battery is increased, and the number of times that the load of the battery is restored to a normal load, based on Battery remaining capacity counting means 1a5 for subtracting the power consumption of the battery corresponding to the number of times of battery load return from a preset remaining capacity of the currently used battery and counting a new remaining battery capacity; A comparing means 1a6 for comparing with the set battery remaining capacity determination value to determine whether or not the new battery remaining capacity is lower than the battery remaining capacity determination value. A warning means 4 for issuing a warning of a decrease in battery voltage when it is determined that the remaining capacity has decreased the battery remaining capacity determination value, further comprising a flow rate measuring device according to claim 1, The battery remaining capacity counting means 1a5 subtracts the power consumption calculated by the power consumption calculating means 1a3 of the flow rate measuring device from the remaining capacity of the currently used battery.
[0016]
According to the gas meter of the present invention described in claim 2, the power consumption of the battery corresponding to the number of times of battery load increase and the number of times of battery load recovery counted by the number-of-operations counting means 1a4, and the power consumption calculating means of the flow rate measuring device The power consumption calculated by 1a3 is subtracted from a preset remaining capacity of the currently used battery, and is counted as a new remaining battery capacity by the remaining battery capacity counting means 1a5. Then, when the comparing means 1a6 determines that the new remaining battery capacity is lower than the low remaining battery capacity determination value, the warning means 4 issues an alarm. Therefore, since the remaining capacity of the battery is calculated based on the power consumption calculated by the flow measurement device and the power consumption of the battery based on the number of times corresponding to the generation of the operation signal, even if pulsation occurs, Since the remaining capacity of the battery is grasped without being affected, and an alarm is issued when the remaining capacity is low, the life of the battery can be accurately managed. Therefore, even if the gas meter is installed in an environment in which pulsation is likely to occur, the remaining capacity of the battery can be grasped without being affected by the pulsation, so that the safe operation of the device can be guaranteed.
[0017]
According to a third aspect of the present invention for solving the above-mentioned problem, as shown in the basic configuration diagram of FIG. 1, in the gas meter according to the second aspect, the normal energization time of the battery for maintaining the operation of the device is reduced. The power supply time counting means 1a7 for counting, and the battery remaining capacity counting means 1a5 subtracts the power consumption of the battery per normal power supply time counted by the power supply time counting means 1a7 from the remaining capacity of the currently used battery. It is characterized by.
[0018]
According to the gas meter of the present invention, when the normal energizing time is counted by the energizing time counting means 1a7, the power consumption of the battery per normal energizing time is calculated from the remaining capacity of the currently used battery. It is decremented by the capacity counting means 1a5. Therefore, since the power consumption per normal energizing time is subtracted from the remaining capacity of the currently used battery, the remaining battery capacity can be accurately grasped in consideration of the constant power consumption of the battery.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a gas meter according to the present invention will be described with reference to FIGS. Here, FIG. 2 is a block diagram showing an example of a schematic configuration of the gas meter of the present invention.
[0020]
Propagation time of the ultrasonic wave at a predetermined time between ultrasonic transducers (transmitter / receiver) which are provided in a gas flow path for transmitting or receiving an ultrasonic wave, is defined as a normal mode and a pulsation generation mode. As shown in FIG. 2, a gas meter to which a flow rate measuring device that extracts by a different extraction method depending on the mode and measures the flow rate of the gas based on the extracted propagation time is applied. It comprises a unit 3, an alarm unit 4, an ultrasonic flow sensor 5, a seismic sensor 6, a communication unit 7, an electromagnetic shut-off valve 8, and a battery 9 such as a lithium battery.
[0021]
The operation unit 2, the display unit 3, the alarm unit 4, the ultrasonic flow sensor 5, the seismic sensor 6, and the communication unit 7 are connected to the microcomputer 1 via the interface unit 11. The electromagnetic shut-off valve 8 is connected to the microcomputer 1 via a shut-off valve driving unit 81.
[0022]
As is well known, the microcomputer 1 includes a CPU 1a, a ROM 1b, and a RAM 1c. The CPU 1a executes basic control, flow rate measurement and pressure detection, battery voltage check, battery remaining capacity monitoring, and control relating to the present embodiment, which will be described later, according to a control program stored in the ROM 1b. The ROM 1b stores various programs such as a basic control program, a control program for flow rate measurement detection, an integrated flow rate calculation, and a battery voltage check program in advance. The RAM 1c basically functions as a work area for temporarily storing variables and data generated in the course of processing performed by the CPU 1a.
[0023]
The operation unit 2 includes a switch group for inputting a command to start or end the gas meter, stop an abnormality alarm, or change a display on the display unit 3. These commands are input to the microcomputer 1 by manually operating the operation unit 2.
[0024]
The display unit 3 receives a command from the microcomputer 1 via the interface unit 11 and, in response to the command, performs an integrated flow rate display and various abnormal alarm displays such as seismic sensing, gas leakage, and battery voltage drop. For example, a known LED or the like is assumed as the display unit 3. When a plurality of LEDs are used as the display unit 3, different types of alarms can be displayed by changing the combination of the LED displays.
[0025]
The alarm unit 4 corresponding to the alarm means in the claims is configured to include an alarm buzzer or the like, receives various data such as alarm information from the microcomputer 1 via the interface unit 11, and responds to the data. Emits an alarm sound. Note that the warning may be implemented in various embodiments depending on the specifications of the gas meter, such as a combination of displaying a warning screen by the display unit 3 and a warning sound emitted by the warning unit 4.
[0026]
The ultrasonic flow sensor 5 includes a pair of ultrasonic vibrators provided in a gas flow path. The ultrasonic flow sensor 5 is connected to the microcomputer 1 via the sensor circuit 51. The microcomputer 1 calculates the flow velocity and flow rate of the gas passing through the gas flow path based on the ultrasonic signal propagation time between the pair of ultrasonic transducers of the ultrasonic flow sensor 5. This will be additionally described later with reference to FIG.
[0027]
The seismic sensor 6 includes a known seismic element that generates an on / off signal in response to shaking due to an earthquake or the like and supplies the signal to the microcomputer 1 via the interface unit 11. For example, the microcomputer 1 determines the degree of swing from the number of on / off signals received within a predetermined time, and if the swing is large, performs an abnormal process such as valve closing control of a shutoff valve.
[0028]
The communication unit 7 has a function of, for example, calling a predetermined message using a public line such as a telephone line. The communication unit 7 is also connected to an NCU (network control unit) 71 for controlling communication with a management center of a gas sales company via a public line such as a telephone line.
[0029]
The electromagnetic shut-off valve 8 corresponding to the shut-off valve in the claims includes a valve drive solenoid coil, and is connected to a shut-off valve drive section 81 which is a drive circuit of the solenoid coil. The shut-off valve drive unit 81 is instructed by the microcomputer 1 to generate a solenoid coil drive signal using the lithium battery 9 as a power supply source, and supplies this to the electromagnetic shut-off valve 8. In response to this, the electromagnetic cutoff valve 8 is opened or closed to shut off the gas flow path.
[0030]
The battery 9 is a power supply source of the gas meter. The battery 9 is frequently used in this type of gas meter because of its long-term use, high versatility, and the like. On the other hand, at low temperatures, the battery 9 is in an inactive state, and the battery voltage is lowered despite the remaining battery level. Sometimes.
[0031]
The interface unit 11 basically has a voltage conversion function between the microcomputer 1 and each of the components 2, 3, 5, 6, and 7 connected thereto.
[0032]
The gas meter having such a configuration is applied to, for example, an LPG supply facility. In this case, the gas meter is interposed in a pipe that connects a pressure regulator that regulates the high-pressure gas contained in the LPG container and a gas combustor to which the regulated gas is supplied.
[0033]
Then, the gas meter normally detects the flow rate of the gas passing through the gas flow path using the ultrasonic flow rate sensor 5, and integrates the flow rate and displays the integrated value on the display unit 3. Further, when the gas meter detects abnormal shaking by the seismic sensor 6, the gas meter displays the fact on the display unit 3 and closes the electromagnetic shut-off valve 8. Further, at the same time, the gas meter transmits a message indicating an abnormal state to the management center of the gas sales company via the communication unit 7, the NCU 71, and a public line such as a telephone line. Further, in this gas meter, the battery voltage is periodically checked, and when the battery voltage drops, the display unit 3 displays the fact.
[0034]
Next, the configuration of the ultrasonic flow sensor 5 and the sensor circuit unit 51 shown in FIG. 2 and the principle of temperature detection using the ultrasonic flow sensor 5 will be described with reference to FIG. FIG. 3 is an explanatory diagram showing the configuration of the sensor circuit unit and the ultrasonic vibrator shown in FIG.
[0035]
As shown in FIG. 3, the sensor circuit unit 51 includes a transmission circuit 511, a reception circuit 512, and a switching circuit 513. The switching circuit 513 is instructed by the microcomputer 1 to alternately use the ultrasonic transducers 5a and 5b (corresponding to the transducer in the claims) as the ultrasonic flow sensor 5 shown in FIG. The connection is switched to 512. When the ultrasonic transducer 5a is connected to the transmission circuit 511, the ultrasonic signal is transmitted from the ultrasonic transducer 5a to the ultrasonic transducer 5b. This ultrasonic signal propagates through the gas to be measured and is received by the ultrasonic transducer 5b connected to the receiving circuit 512. The ultrasonic transducer 5b that has received the ultrasonic signal generates a signal corresponding to the ultrasonic signal, and supplies the signal to the microcomputer 1 via the receiving circuit 512. On the other hand, when the ultrasonic transducer 5b is connected to the transmission circuit 511, transmission and reception of ultrasonic signals are performed in the opposite direction. The microcomputer 1 can calculate the flow velocity and the flow rate of the measured gas based on the propagation times of the ultrasonic signals in both directions.
[0036]
That is, it is assumed that the pair of ultrasonic vibrators 5a and 5b are disposed to face the gas flow path 52 at an angle θ. Here, the average flow velocity of the gas to be measured flowing in the direction indicated by the arrow in the drawing is V, the distance between the ultrasonic vibrators 5a and 5b is L, and the line connecting the ultrasonic vibrators 5a and 5b and the gas flow path 52 Assuming that the angle formed by the central axis is θ, and the up and down propagation times of the ultrasonic signal are tu and td, respectively,
The average flow velocity V is, as already known,
V = L / 2 COS θ (1 / td−1 / tu). ... (Equation 1)
Then, assuming that the flow rate is Q, the passage area is S, and the correction count is K,
Q = KSV (Equation 2)
Thus, the flow rate Q of the fluid passing through the gas flow path 52 is calculated.
[0037]
FIG. 4 is a diagram for explaining the normal mode and the pulsation generation mode.
In FIG. 4, C indicates a sampling time per cycle (corresponding to a predetermined time, for example, 2 seconds). In the normal mode, first, energization of the ultrasonic transducer 5b is performed X times, so that the upstream propagation time is measured X times, and the average thereof is the upstream propagation time tu at the sampling time C. Similarly, when the energization of the ultrasonic transducer 5a is performed X times, the downstream propagation time is measured X times, and the average thereof is the downstream propagation time td in the sampling time C.
[0038]
In the pulsation generation mode, the above-described measurement for the up and down is performed Y times, and the measurement for the up and down is repeated Z times. Then, the averages of the up and down times of Y * Z times are the propagation times tu and td. That is, the number of times of sampling in the sampling time C is 2X times (X + X) in the normal mode by adding up X times and down X times, and in the pulsation generation mode, adding up Y times and down Y times. 2YZ times {(Y + Y) * Z}, which is the product of this result and the number of repetitions.
[0039]
As described above, in the pulsation generation mode, the measurement is performed more times than in the normal mode, so that the pulsation is not affected by the pressure fluctuation due to the pulsation. That is, in the pulsation generation mode, power is supplied to the ultrasonic transducers 5a and 5b more times than in the normal mode by 2YZ-2X times, so that the power consumption is increased accordingly.
[0040]
Further, the ROM 1b stores a program indicating the above-described arithmetic expressions of (Equation 1) and (Equation 2), and a program for each mode per sampling time C corresponding to each processing such as cutoff, return, and measurement of propagation time. The power consumption information indicating the power consumption and the CPU 1a are compared with the normal mode counting means, the pulsation occurrence mode counting means, the power consumption calculating means, the operation number counting means, the energizing time counting means, the remaining battery capacity coefficient means in the claims. And a program for functioning as means.
[0041]
For example, the power consumption information can identify normal power consumption data and pulsation power consumption data indicating power consumption required for 2X times and 2YZ times of energization corresponding to the normal mode and the pulsation generation mode, respectively. It has a configuration. Then, by counting each number of times of the sampling time (predetermined time) C in which the propagation time is extracted in the normal mode and the pulsation generation mode, the power consumption can be calculated without being affected by the pulsation. Is possible. Therefore, in the present embodiment, the ROM 1b functions as a power consumption information storage unit.
[0042]
FIG. 5 is a diagram showing an example of a memory map according to the present invention in the RAM in FIG. As shown in FIG. 3, the RAM 1c has a storage area for storing various data such as the number of cutoff times, the number of return times, the number of normal mode times, the number of pulsation occurrence times, the power-on time, and the remaining battery capacity.
[0043]
The number of shutoffs is the number of times the electromagnetic shutoff valve 8 is shut off, and stores the number of times that the CPU 1 a outputs a shutoff signal to the shutoff valve drive 81 to shut off the electromagnetic shutoff valve 8. Further, the power consumption information described above includes cutoff power consumption data indicating the power consumption of the battery 9 required for one shutoff of the electromagnetic shutoff valve 8. It is possible to calculate the power consumption with respect to the number of times the valve 8 is shut off.
[0044]
The number of times of return is the number of times that the electromagnetic shut-off valve 8 has been returned, and stores the number of times that the CPU 1a has detected a return operation to the operation unit 2. The power consumption information described above includes return power consumption data indicating the power consumption of the battery 9 required for one return of the electromagnetic shutoff valve 8, and the electromagnetic shutoff is performed based on the number of times of return and the return power consumption data. Power consumption with respect to the number of times the valve 8 returns can be calculated.
[0045]
Therefore, the CPU 1a counts the number of times that the apparatus has been operated in a predetermined state to increase the load of the battery 9 and the number of times that the load of the battery has returned to the normal load. It functions as a number counting means. Since this processing is basically the same as that of Patent Document 2, the description of the processing is omitted.
[0046]
The number of times of the sampling time (predetermined time) C obtained by extracting the propagation time between the ultrasonic transducers in the normal mode and the pulsation occurrence mode is stored in the normal mode number and the pulsation occurrence mode number. Is done. The power consumption can be calculated based on the power consumption data for normal use and the number of times of normal mode of the power consumption information described above, and the pulsation power consumption data and the number of times of pulsation occurrence mode.
[0047]
In the power-on time, the CPU 1a accumulates and stores the normal operation time of the apparatus every predetermined time. Therefore, since the CPU 1a counts the normal energizing time by the battery 9 that maintains the operation of the apparatus, the CPU 1a functions as an energizing time counting unit. This processing is also basically the same as that of Patent Document 2, and the description of the processing is omitted.
[0048]
The remaining power of the battery 9 currently stores the power consumption calculated for each predetermined time based on each of the number of cutoffs, the number of times of return, the number of times of normal mode, the number of times of pulsation mode, and the normal operation time. It is subtracted from the remaining battery capacity and updated.
[0049]
Next, an example of the flow rate measurement processing of the gas meter according to the present invention will be described below with reference to the flowchart of FIG. FIG. 6 is a flowchart showing an example of the flow rate measurement process executed by the CPU of FIG.
[0050]
When the flow rate measurement process shown in FIG. 6 is executed, in step S11, a timer that times out when the sampling time C elapses is started. Thereafter, in step S12, normal sampling process is executed, and when the process ends, step S13 is executed. Proceed to.
[0051]
In the normal sampling process, as described in the normal mode of FIG. 4 described above, the sensor circuit unit 51 is controlled so that the transmission circuit 511 is connected to the ultrasonic transducer 5b, and the transmission circuit 511 is energized. The ultrasonic signal propagates through the gas to be measured and is received by the ultrasonic transducer 5b connected to the receiving circuit 512. Then, the ultrasonic transducer 5b having received the ultrasonic signal generates a signal corresponding to the ultrasonic signal, and the signal is supplied to the microcomputer 1 via the receiving circuit 512, so that the upward propagation time is determined by the CPU 1a. Measured. This process is performed X times, and the upstream propagation times are stored in the RAM 1c. Thereafter, the sensor circuit unit 51 is controlled so that the transmission circuit 511 is connected to the ultrasonic transducer 5a, and the measurement of the propagation time of X times is performed in the same manner as in the above-described case, and the propagation times of those times are measured. Are also stored in the RAM 1c.
[0052]
In step S13, the average of the upstream and downstream propagation times sampled at the current sampling time C is calculated as the upstream and downstream propagation times tu and td and stored in the RAM 1c. And td and the arithmetic expression of the above (formula 1), the current flow velocity V is calculated, and then, in step S15, the flow rate Q is calculated based on the calculated current flow velocity V and the above calculation expression of the above (formula 2). Then, the flow rate Q is stored in the RAM 1c, and then the process proceeds to step S16.
[0053]
In step S16 (normal mode counting means), the number of times of normal mode of the RAM 1c is updated by incrementing, and thereafter, in step S17, a difference between the current flow velocity V and the previous flow velocity Vb of the RAM 1c is calculated as a flow velocity change amount. Then, the process proceeds to step S18.
[0054]
In step S18, it is determined whether an end request has been received. If it is determined that the termination request has been received (Y in step S18), the processing is terminated. If it is determined that the termination request has not been received (N in step S18), it is determined in step S19 whether or not the timer has timed out. If it is determined that the timer has not timed out (N in step S19), the process returns to step S18. If it is determined that the timer has timed out (Y in step S19), in step S20, the current flow velocity V is stored in the RAM 1c as the previous flow velocity Vb, and then the process proceeds to step S21.
[0055]
In step S21, it is determined whether or not pulsation has occurred based on whether or not the amount of change in flow velocity in the RAM 1c is equal to or greater than a pulsation determination threshold value stored in advance in the ROM 1b. If it is determined that the flow velocity change amount is smaller than the pulsation determination value, that is, it is determined that pulsation has not occurred (N in step S21), the process returns to step S11, and a series of processes is repeated.
[0056]
If it is determined in step S21 that the amount of change in the flow velocity is equal to or greater than the pulsation determination threshold, that is, it is determined that pulsation has occurred (Y in step S21), the same timer as in step S11 is started in step S22. Then, in step S23, a pulsation sampling process is executed, and when the process ends, the process proceeds to step S24.
[0057]
In the pulsation sampling process, as described in the pulsation generation mode in FIG. 4 described above, the sensor circuit unit 51 is controlled so that the transmission circuit 511 is connected to the ultrasonic transducer 5b, and the transmission circuit 511 is energized. Thus, the ultrasonic signal propagates in the gas to be measured, and is received by the ultrasonic transducer 5b connected to the receiving circuit 512. Then, the ultrasonic transducer 5b receiving the ultrasonic signal generates a signal corresponding to the ultrasonic signal, and the signal is supplied to the microcomputer 1 via the receiving circuit 512, and the upstream propagation time is measured by the CPU 1a. . This process is performed Y times, and the upstream propagation times are stored in the RAM 1c. After that, the sensor circuit unit 51 is controlled so that the transmission circuit 511 is connected to the ultrasonic transducer 5a, and the measurement of the propagation time of Y times is performed in the same manner as in the above-described case, and the propagation times of those downlinks are measured. Are also stored in the RAM 1c. The measurement of the up and down is set as one set, and this set is repeated Z times, and the measurement result is stored in the RAM 1c.
[0058]
In step S24, the average of the up and down propagation times sampled during the current sampling time C is calculated as the up and down pulsation propagation times tu and td and stored in the RAM 1c. Thereafter, in step S25, the RAM 1c The current flow velocity V is calculated based on the propagation times tu and td and the arithmetic expression of the above (Equation 1). Thereafter, in step S26, based on the calculated current flow velocity V and the calculation expression of the above (Equation 2). The flow rate Q is calculated, this flow rate Q is stored in the RAM 1c, and then updated in step S27 (pulsation generation mode counting means) by incrementing the number of pulsation generation modes of the RAM 1c, and thereafter, the process returns to step S17. A series of processing is repeated.
[0059]
As described above, in the present embodiment, steps S11 to S16 are processing corresponding to the normal mode, and steps S22 to S27 are processing corresponding to the pulsation stop mode.
[0060]
Next, an example of the remaining battery capacity monitoring process of the gas meter according to the present invention will be described below with reference to the flowchart of FIG. FIG. 7 is a flowchart showing an example of the remaining battery charge monitoring process executed by the CPU of FIG.
[0061]
When the battery remaining capacity monitoring process shown in FIG. 7 is executed, in step S51 (battery remaining capacity counting means), the number of times of shutting off the RAM 1c, the number of times of return, the number of times of normal mode, the number of times of pulsation occurrence mode, the energizing time, etc. The power consumption is calculated based on the power consumption data per unit time (the above-described normal power consumption data, pulsation power consumption data, etc.), and this power consumption is subtracted from the previous battery remaining capacity of the RAM 1 c to Is calculated in the RAM 1c, and then the process proceeds to step S52.
[0062]
In step S52 (determination means), it is determined whether or not the remaining battery charge is low based on whether or not the remaining battery capacity of the RAM 1c has decreased below a battery remaining capacity low determination value stored in the ROM 1b in advance. You. When it is determined that the remaining battery charge is equal to or greater than the remaining battery charge determination value, that is, when it is determined that the remaining battery charge is not low (N in step S52), the process returns to step S51. On the other hand, when it is determined that the remaining battery capacity is lower than the remaining battery capacity low determination value, that is, when it is determined that the remaining battery capacity is low (Y in step S52), the process proceeds to step S53.
[0063]
In step S53, the voltage value at both ends of the dummy load (not shown) is detected, and in step S54, it is determined whether the voltage value has dropped below the voltage drop determination value stored in the ROM 1b in advance. When it is determined that the voltage value has not dropped below the voltage drop determination threshold (N in step S54), it is determined that the battery life is near but there is enough power, and the process returns to step S51. When it is determined that the voltage value is lower than the voltage drop determination value (Y in step S54), it is determined that the battery life has expired, and the process proceeds to step S55.
[0064]
In step S55, the shutoff signal is output to the shutoff valve driving unit 81, so that the electromagnetic shutoff valve 8 is shut off. Then, in step S56, the alarm information for outputting an alarm is output to the alarm unit 4, so that the alarm is output. An alarm is issued by the unit 4, and the process is thereafter terminated.
[0065]
Next, an example of the operation (action) of the above-described gas meter according to the present invention will be described below.
[0066]
The gas meter in the normal mode measures the ascending and descending propagation times X times at each sampling time C and averages the propagation times tu and td at the sampling time C. Based on the propagation times tu and td, the flow velocity V, The flow rate Q is calculated. When the measurement in the normal mode for the sampling time C is completed, the number of times in the normal mode is incremented.
[0067]
When the gas meter detects that the supply gas pressure fluctuates in accordance with the use of the combustion equipment based on the flow velocity change amount calculated from the flow velocity V, the gas meter sets the pulsation generation mode to the rising and falling at the sampling time C. The propagation time tu and td are calculated by repeating the measurement of the propagation time Y times Z times, and the flow velocity V and the flow rate Q are calculated based on the propagation times tu and td. Then, when the measurement of the pulsation generation mode with respect to the sampling time C is completed, the pulsation generation mode number is incremented.
[0068]
The remaining capacity of the battery 9 is calculated based on power consumption data per unit time for each of the number of times the RAM 1c is shut off, the number of times of return, the number of times of normal mode, the number of modes of pulsation occurrence, the energizing time, and the like. The current battery remaining capacity is calculated by subtracting the power consumption from the remaining battery capacity of the RAM 1c up to the previous time. When the remaining battery capacity is low and the battery voltage is low, the electromagnetic shutoff valve 8 is shut off, and an alarm is issued by the alarm unit 4.
[0069]
As described above, the gas meter stores the power consumption information indicating the power consumption per sampling time (predetermined time) C corresponding to the normal mode and the pulsation generation mode in the ROM 1b. The number of times of the sampling time C corresponding to the occurrence mode is counted, the power consumption for driving the transducer is calculated based on the counting result and the power consumption information, and the battery is calculated based on the power consumption. Since the remaining capacity of the battery 9 is calculated, even if a pulsation occurs, the remaining capacity of the battery 9 is grasped without being affected by the pulsation. When the remaining capacity is small, the alarm unit 4 issues an alarm. Life can be managed accurately.
[0070]
Therefore, even if the gas meter is installed in an environment where pulsation is likely to occur, the remaining battery capacity of the gas meter can be grasped without being affected by the pulsation, and the safe operation of the device can be guaranteed.
[0071]
In addition, since the power consumption per normal energizing time is subtracted from the remaining capacity of the currently used battery 9, it is possible to accurately grasp the remaining battery capacity in consideration of the constant power consumption of the battery 9. it can.
[0072]
Furthermore, in the present embodiment, since the double check of the remaining capacity of the battery 9 and the decrease of the battery voltage is performed, for example, even if the remaining battery capacity is small and the battery voltage is not small, it is determined that the battery 9 is normal. In addition, the remaining battery capacity can be more accurately grasped, and erroneous determination can be prevented.
[0073]
Since the above-described gas meter has the communication unit 7, if the alarm information is notified to a gas company or the like which manages the gas meter, the replacement of the battery 9 can be promptly arranged.
[0074]
The gas meter according to claim 2, further comprising a shutoff valve that shuts off the gas flow path when the comparing unit determines that the new remaining battery capacity has decreased the battery remaining capacity low determination value. It is characterized by the following.
[0075]
With this configuration of the gas meter of the present invention, the shutoff valve shuts off the gas flow path when the comparison means determines that the new remaining battery capacity has decreased the remaining battery capacity low determination value. Therefore, when the new remaining battery capacity becomes lower than the battery remaining capacity determination value, the gas flow path is shut off to prevent the use of the battery, so that the safety can be further improved.
[0076]
【The invention's effect】
As described above, according to the flow rate measurement device of the present invention described in claim 1, power consumption information indicating power consumption per predetermined time corresponding to the normal mode and the pulsation generation mode is stored, It is possible to count a predetermined time corresponding to the normal mode and the pulsation generation mode, and calculate the power consumed for driving the transducer based on the counting result and the power consumption information. Therefore, since the flow rate measuring device calculates the power consumption corresponding to the normal mode and the pulsation generation mode, it is possible to accurately calculate the power consumption even when the pulsation occurs. By monitoring the remaining capacity, it is possible to grasp the remaining capacity of the battery without being affected by pulsation, so that accurate management of the battery life is possible and the safe operation of the device can be guaranteed. It works.
[0077]
As described above, according to the gas meter of the present invention described in claim 2, the battery is based on the power consumption of the battery based on the power consumption calculated by the flow rate measuring device and the number of times corresponding to the generation of the operation signal. The remaining battery capacity is calculated, so even if a pulsation occurs, the remaining battery capacity can be grasped without being affected by the pulsation, and when the remaining battery capacity is low, an alarm is issued. Can be. Therefore, even if the gas meter is installed in an environment where pulsation is likely to occur, the remaining capacity of the battery can be grasped without being affected by the pulsation, so that there is an effect that the safe operation of the device can be guaranteed.
[0078]
According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, the power consumption per normal energization time is subtracted from the remaining capacity of the currently used battery. The remaining battery capacity can be accurately grasped in consideration of the typical power consumption.
[Brief description of the drawings]
FIG. 1 is a diagram showing a basic configuration of a gas meter to which a flow measuring device of the present invention is applied.
FIG. 2 is a block diagram illustrating an example of a schematic configuration of a gas meter according to the present invention.
FIG. 3 is an explanatory diagram showing a configuration of a sensor circuit unit and an ultrasonic transducer shown in FIG. 2, and an operation of the ultrasonic transducer.
FIG. 4 is a diagram for describing a normal mode and a pulsation generation mode.
FIG. 5 is a diagram showing an example of a memory map according to the present invention in a RAM in FIG. 2;
FIG. 6 is a flowchart illustrating an example of a flow rate measurement process executed by the CPU of FIG. 2;
FIG. 7 is a flowchart illustrating an example of a remaining battery capacity monitoring process executed by the CPU of FIG. 2;
[Explanation of symbols]
1a1 Normal mode counting means (CPU)
1a2 Pulsation occurrence mode counting means (CPU)
1a3 Power consumption calculation means (CPU)
1a4 Operation count counting means (CPU)
1a5 Battery remaining capacity counting means (CPU)
1a6 Comparison means (CPU)
1b Power consumption information storage means (ROM)
4 Warning means (warning section)

Claims (3)

An extraction method in which the propagation time of the ultrasonic wave at a predetermined time between the transducers for transmitting or receiving ultrasonic waves provided in the gas flow path through which the gas flows differs between the normal mode and the pulsation generating mode. In the flow measurement device that measures the flow rate of the gas based on the extracted propagation time,
Power consumption information storage means for storing power consumption information indicating the power consumption per predetermined time corresponding to the normal mode and the pulsation occurrence mode,
A normal mode counting means for counting the number of times of the predetermined time in which the propagation time is extracted by the normal mode,
A pulsation occurrence mode counting means for counting the number of times of the predetermined time in which the propagation time is extracted by the pulsation occurrence mode,
Power consumption calculating means for calculating power consumption based on the number of times counted by the normal mode counting means, the number of times counted by the pulsation occurrence mode counting means, and the power consumption information stored in the power consumption information storage means. When,
A flow rate measuring device comprising: Equipped with a battery as a drive power supply, the number of times the device is operated in a predetermined state based on an operation signal generated by an input from the outside of the device and the load of the battery is increased, and the load of the battery is changed to a normal load. An operation number counting means for counting the number of times of return, and subtracting the power consumption of the battery corresponding to the number of times of battery load increase and the number of times of battery load return from the remaining capacity of the currently used battery set in advance to obtain a new remaining battery capacity. A battery remaining capacity counting means for counting, comparing the new battery remaining capacity with a predetermined battery remaining capacity determination value, and determining whether the new battery remaining capacity is lower than the battery remaining capacity determination value. And a warning means for issuing a battery voltage drop warning when it is determined that the new battery remaining capacity has decreased the battery remaining capacity determination value by the comparing means. ,
Further provided is a flow measuring device according to claim 1,
The gas meter, wherein the battery remaining capacity counting means subtracts the power consumption calculated by the power consumption calculating means of the flow rate measuring device from the remaining capacity of the currently used battery. The apparatus further includes an energization time counting unit that counts a normal energization time by the battery that maintains the operation of the device, and the battery remaining capacity counting unit calculates the power consumption of the battery per normal energization time counted by the energization time counting unit. The gas meter according to claim 2, wherein the remaining capacity of the currently used battery is subtracted from the remaining capacity.

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