JP3651459B2 - Flow measurement control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flow rate measurement control device that integrates and measures an instantaneous flow rate of gas or the like.
[0002]
[Prior art]
As shown in FIG. 5, a conventional flow measurement control device that measures and integrates this kind of instantaneous flow rate includes ultrasonic transmitters / receivers 2 a and 2 b in a part of the fluid pipe 1, and a signal from the measurement start means 3. Then, the flow rate measurement is started and the propagation time from the ultrasonic transceivers 2a to 2b is measured by the time measuring means 4.
[0003]
Also, since digital sampling is intermittent sampling, if pressure pulsation occurs, the flow rate measurement value varies depending on the measurement timing, so to obtain an accurate flow rate, the measurement interval is shortened and the number of measurements is increased, and the measurement time The measurement mode that averages the measured values by lengthening the length is also used.
[0004]
[Problems to be solved by the invention]
However, the conventional flow measurement control device has the following problems.
[0005]
In other words, since digital sampling is intermittent, if pressure fluctuations occur, it is necessary to increase the number of measurements and average the measurement values to obtain an accurate flow rate, so the measurement interval is shortened and the measurement time is lengthened. There was a need.
[0006]
For this reason, a battery-driven gas meter that also functions as a safety function, such as shutting off during abnormal use, requires a large battery capacity when measuring pressure pulsation at all times. In view of the above, the economic cost has become an issue in terms of gas meter configuration.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention measures a transmitter / receiver that transmits or receives a sound wave in a fluid, a repeating unit that performs transmission / reception between the transmitter / receiver a plurality of times, and a sound wave propagation time measured by the repeating unit. Measuring means, flow rate calculating means for calculating a flow rate from a value obtained by integrating the respective values of the time measuring means, measurement mode monitoring means for monitoring the occurrence of pressure pulsation of the fluid, and outputs of the measurement mode monitoring means Means for storing, and a measurement number setting means for setting how many times measurement sampling is performed at the time of pressure pulsation, with the number of measurements set by the repetition number setting means as one measurement number, and the measurement mode monitoring means includes: The operating time or the number of driving times of the measurement number setting means is integrated .
[0008]
Accordingly, since the pressure fluctuation occurrence state can be monitored from the operation state of the measurement number setting means, the battery consumption state and the meter management can be quickly performed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The first invention is a transmitter / receiver that transmits or receives a sound wave in a fluid, a repeating unit that performs transmission / reception between the transmitter / receiver a plurality of times, a time measuring unit that measures a sound wave propagation time measured by the repeating unit , a flow rate calculation means for calculating the flow rate from the integrated value of each value before Symbol timing means, a measurement mode monitoring means for monitoring the occurrence of pressure pulsations of the fluid, the means for storing the output of the measurement mode monitoring means By providing, it is possible to grasp the frequency of occurrence of pressure pulsation.
[0010]
According to the second aspect of the present invention, it is possible to grasp the pressure pulsation occurrence time by managing the operation time of the measurement number setting means.
[0011]
In the third aspect of the invention, the information of the pressure pulsation generation area and the generation time can be grasped at the centralized monitoring center by notifying the output of the measurement mode monitoring unit by the communication unit.
[0012]
According to the fourth aspect of the invention, the meter reader can confirm by displaying the output of the measurement mode monitoring means on the meter pointer value display.
[0013]
According to the fifth aspect of the present invention, the history of the output of the measurement mode monitoring means is recorded in the nonvolatile memory element, whereby the meter management can be performed as the battery capacity consumption cause information.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
(Example 1)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the 1st transmitter / receiver 6a which transmits an ultrasonic wave in the middle of the fluid pipe line 5, and the 2nd transmitter / receiver 6b which receives are arrange | positioned in the flow direction. Reference numeral 7 denotes a transmission circuit to the first transmitter / receiver 6a, and reference numeral 8 denotes an amplifier circuit for the signal received by the second transmitter / receiver 6b. The amplified signal is compared with the reference signal by the comparison circuit 9, and a signal higher than the reference signal is obtained. When the signal is detected, the number of times set by the repetition number setting unit 10 is delayed by the delay unit 12 by the repetition unit 11 and then the ultrasonic signal is repeatedly transmitted by the trigger circuit 13. The time when the number of times set by the repeat count setting means 10 is repeated is obtained by the clock means 14 for counting pulses of the clock for clocking, and the value is stored in the storage means 15 built in the microcomputer 19. In this way, ultrasonic waves are transmitted from the first transmitter / receiver 6a to the second transmitter / receiver 6b, that is, from upstream to downstream (hereinafter referred to as upstream transmission).
[0016]
Next, the switching means 16 switches between transmission and reception of the first transmitter / receiver 6a and the second transmitter / receiver 6b, from the second transmitter / receiver 6b to the first transmitter / receiver 6a, that is, from downstream to upstream (hereinafter referred to as downstream transmission). Then, an ultrasonic signal is transmitted, this transmission is repeated as described above, and the time is counted.
[0017]
From the time difference, the flow rate value is obtained by the flow rate calculation means 17 of the microcomputer 19 in consideration of the size of the pipeline and the flow state.
[0018]
Reference numeral 18 denotes a measurement number setting means for setting how many times measurement sampling is performed with the measurement number set by the repetition number setting means 10 as one measurement number. This measurement is performed when the measurement gas has pressure pulsation. carry out.
[0019]
FIG. 2 shows the state of measurement sampling when there is a pressure pulsation. During the time T1, the upstream transmission described above is repeated 6 times, and the propagation time is counted by the timing means 14 and stored in the storage means 15. The propagation time t1 is stored.
[0020]
Next, the transmitter / receivers 6a and 6b are switched, and during the time T2, the downstream transmission is performed 6 times and the propagation time t2 is stored. Further, after a predetermined time tb has elapsed, upstream transmission is performed during time T3 and downstream transmission is performed during time T4, and propagation times t3 and t4 are stored.
[0021]
In this way, the upstream transmission and the downstream transmission are intermittently performed as a pair, and in this embodiment, measurement is performed 40 times each. The propagation time at that time is stored in the storage means 15.
[0022]
The data in the storage unit 15 is calculated by the flow rate calculation unit 17 to calculate the flow rate. In this calculation, for example, the sum total of upstream transmissions is calculated, the average value of propagation times per one time is calculated from the sum of the number of repetitions, and the average value of propagation times per one time of downstream transmission is calculated in the same manner. Calculate from the time difference of time or the difference of reciprocal time.
[0023]
3 and 4 illustrate the respective measurement modes, with the horizontal axis representing time and the vertical axis representing flow rate. Usually, as shown in FIG. 3, the upstream transmission and the downstream transmission described above are performed a predetermined number of times in the measurement cycle TS time, and the flow rate is measured. When pressure pulsation occurs in the measurement pipe 1, the measurement shown in FIG. 4 is performed. That is, the flow rate measurement in the measurement mode described in FIG. 2 is executed.
[0024]
In these measurement mode selections, for example, the measurement mode selection unit 20 of the microcomputer 19 determines the fluctuation value from the calculation result of the flow rate calculation means 17. Alternatively, a method such as using a pressure sensor is used.
[0025]
The measurement mode monitoring unit 21 manages the occurrence of pressure pulsation by counting the number of times the measurement number setting unit 18 is driven or measuring the duration. The output of the measurement mode monitoring means 21 can display the time or the number of times on an LCD which is a pointer value display 22.
[0026]
Further, the gas meter is equipped with a communication means 23 for performing remote meter reading, and it is possible to report to the management center by this communication means.
[0027]
The output of the measurement mode monitoring means 21 is stored in a non-volatile memory 24 provided outside the microcomputer 19 so that the history of the measurement mode is confirmed even when the microcomputer 19 is stopped due to battery capacity exhaustion. be able to.
[0028]
As is apparent from the above description, the following effects can be obtained according to the flow rate measurement control device of this embodiment.
[0029]
(1) By measuring a small number of repetitions a plurality of times, it is possible to accurately measure the flow rate with respect to the pressure pulsation flow, and it is possible to manage the pressure pulsation occurrence state by monitoring the measurement mode.
[0030]
(2) by monitoring the measurement mode, it is not necessary to mount a large battery capacity to assume all the pressure pulsation flow measurement mode is less incidence of pressure pulsations, with economic cost advantages by monitoring the frequency gas meter Can be provided.
[0031]
【The invention's effect】
As described above, the present invention is Ru can accurately grasp the fluid status.
[Brief description of the drawings]
FIG. 1 is a block diagram of a flow rate measurement control device according to a first embodiment of the present invention. FIG. 2 is a pressure pulsation flow measurement waveform diagram of the device. FIG. 3 is a normal flow rate measurement sequence diagram of the device. Pressure pulsation measurement sequence diagram [Fig. 5] Block diagram of a conventional flow rate measurement device [Explanation of symbols]
DESCRIPTION OF SYMBOLS 5 Fluid line 6a, 6b Transmitter / receiver 10 Repeat number setting means 11 Repeat means 14 Time measuring means 17 Flow rate calculating means 18 Measurement number setting means 19 Microcomputer 21 Measurement mode monitoring means 22 Liquid crystal display 23 Communication means 24 External memory

Claims (4)

A transmitter / receiver that transmits or receives a sound wave in a fluid, a repeating unit that performs transmission / reception between the transmitter / receiver a plurality of times, a time measuring unit that measures a sound wave propagation time measured by the repeating unit, and each of the time measuring unit A flow rate calculation means for calculating a flow rate from a value obtained by integrating the values, a measurement mode monitoring means for monitoring the occurrence of pressure pulsation of the fluid, a means for storing an output of the measurement mode monitoring means, and a repetition count setting means. A measurement number setting means for setting how many times measurement sampling is performed at the time of pressure pulsation using the set measurement number as one measurement number, and the measurement mode monitoring means determines the operation time or the drive number of the measurement number setting means. A flow measurement control device that integrates . Flow measurement control device according to claim 1 Symbol placement to inform the communication means outputs the measurement mode monitoring means. Flow measurement control device according to claim 1 Symbol placing the output displayed on the liquid crystal display of the measurement mode monitoring means. Flow measurement and control device outputs the claims 1 Symbol placement recorded to the nonvolatile memory device of the measurement mode monitoring means.

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