JP5092185B2 - Flow measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention particularly relates to an apparatus for measuring the flow rate of a gas or a liquid using ultrasonic waves.
[0002]
[Prior art]
  Conventionally, this type of flow rate measuring apparatus has been known as disclosed in JP-A-11-64054. The configuration will be described below with reference to FIG. In FIG. 16, 1 is an ultrasonic flow meter as an instantaneous flow rate measuring means, 2 is a seismic means for measuring a plurality of earthquake levels, 3 is a motor type shut-off valve as a flow path adjusting means, 4 is an ultrasonic flow meter 1 It is a control means which adjusts the opening degree of a flow path using a motor type shut-off valve according to the measured instantaneous flow rate of this and the measured earthquake level of the seismic sensing means 2. The seismic sensing means 2 includes three acceleration sensors, and the X sensor 5, the Y sensor 6, and the Z sensor 7 have detection main sensitivities in directions orthogonal to each other. Each sensor outputs a voltage in proportion to the magnitude of vibration acceleration. Therefore, the acceleration level in the actual vibration direction can be calculated by converting the voltage values of the three sensors and performing vector synthesis. Here, 8 is a battery as a power source for the ultrasonic flow meter 1, the X sensor 5, the Y sensor 6, the Z sensor 7, the motor control valve 3, and the control means 4 of the seismic sensing means 2. The power supply of the battery 8 is controlled by the power supply control means 9.
[0003]
  Next, the operation and action will be described. First, the power control means 9 provided in the control means 4 turns on the power and supplies driving electricity to the ultrasonic sensor 1 and the X sensor 5, Y sensor 6 and Z sensor 7 of the seismic sensing means 2. Then, the instantaneous flow rate is measured by the ultrasonic flow meter 1 and simultaneously the voltage value of each sensor of the seismic sensing means is measured. Then, the power is temporarily turned off to save power. The control means calculates vibration acceleration obtained by vector calculation by converting the voltage values of the three sensors into acceleration. When the vibration acceleration is less than a first predetermined value, for example, 150 gal, the instantaneous flow rate and the measurement of each sensor are repeated again with the intermittent operation of turning on and off the power.
[0004]
  On the other hand, if it is 150 gal or more, the power to the seismic means is turned on, and for example, a vibration acceleration waveform for a predetermined time of 3 seconds is measured. During this measurement, a vector-calculated value is obtained from the voltage values in the three directions, and if the second predetermined value, for example, 980 gal or more, the flow path is opened by the motor type shut-off valve. If it is less than 980 gal, a composite waveform is obtained from the measured data series in the three directions, and a discrimination coefficient for determining whether or not it is an earthquake is calculated. For example, the discrimination coefficient is obtained from the peak value of the composite waveform and the dispersion value of the zero cross period of the waveform. Whether or not it is an earthquake is determined based on the discrimination coefficient. If it is determined that the earthquake is not an earthquake, the instantaneous flow rate and the measurement of each sensor are repeated again.
[0005]
  Further, when it is determined that the earthquake is detected, if the measured instantaneous flow rate is less than a predetermined flow rate, for example, less than 100 liters / hour, the flow path is semi-closed by a motor type shut-off valve. If it is determined that there is an earthquake and the measured instantaneous flow rate is 100 liters / hour or more, the flow path is immediately closed by the motor type shut-off valve. Then, after closing the flow path, the flow rate is measured with an ultrasonic flowmeter when a predetermined time, for example, 1 hour elapses, and if the measured flow rate is greater than the predetermined flow rate, for example, 3 liters / hour, wait for 1 hour to elapse again. However, if the flow rate is less than 3 liters / hour, the flow path is opened by the motor control valve.
[0006]
  In this way, safety measures that match the level and flow rate of an earthquake can be instantaneously provided by a sensor that outputs a voltage signal corresponding to vibration acceleration and an ultrasonic flow meter that can measure the instantaneous flow rate. And since the seismic sensing means has three sensors arranged in directions perpendicular to each other, the acceleration level in the main direction of the earthquake can be measured by vector synthesis of the three signals, and the seismic sensing means is tilted. Even if it is installed, the resultant vector can be measured, so that the degree of freedom can be given to the installation of the ultrasonic flowmeter. In addition, since the opening of the flow path can be freely adjusted by the motor type shut-off valve,InstantThe opening of the flow path can be adjusted steplessly according to the flow rate and the earthquake level, and safety measures can be taken in various cases.
[0007]
  In addition, the control means, if the earthquake level is greater than or equal to a predetermined level, and it is determined as an earthquake by waveform discriminationsoHowever, the flow rate can be stopped only when the instantaneous flow rate is equal to or higher than the predetermined flow rate.
[0008]
[Problems to be solved by the invention]
  However, the above-described conventional technology is configured to close the shut-off valve only during an earthquake. In normal use, the fluid flows in the gas flow channel and the water flow channel only at the time of preparing a meal or using a bath, and at other times, the fluid may be considered as waiting. In this case, it is at most several hours that the device operates for 24 hours a day, and the flow rate is measured at other times. Even in this measurement, the electronic flow measuring device uses electric power, and there is a problem that a large-capacity power supply must be prepared.
[0009]
[Means for Solving the Problems]
  In order to solve the above problems, the control means of the present invention changes the measurement operation of the flow rate measuring means when the flow rate on-off valve is closed. Thereby, when the fluid is not flowing, the energy saving effect is enhanced by making the operation of the flow rate measuring means less than usual.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
  The invention according to claim 1 of the present invention is installed in at least one of the flow rate measuring means for measuring the flow rate of the fluid to be measured flowing in the flow path using the propagation time difference of the ultrasonic waves, and at least one upstream or downstream of the flow rate measuring means. A flow rate on / off valve, a control means for controlling the flow rate measuring means and the flow rate on / off valve,The flow rate measuring means measures the flow rate of the fluid to be measured even after the flow rate on-off valve is closed, and stops the measurement after a first time has elapsed.The control means isThe on-off valve is not opened until after a lapse of a second time longer than the first time.This is a flow rate measuring device. Then, after the flow rate on / off valve is closed, the energy saving effect is enhanced by reducing the operation of the flow rate measuring means to be less than usual. In addition, even if the flow rate on / off valve is closed, the flow may be generated on the downstream side for a while, so that a precise supply flow rate is obtained by measuring the flow rate for a certain time with a timer.Furthermore, once the flow rate on / off valve is closed, it is not opened within a predetermined time, thereby reducing the influence on the piping system due to hunting and the load on the drive system.
[0013]
  Claim2The described invention is configured not to perform measurement particularly when the fluid to be measured is not filled in the flow path by the flow rate measuring means according to the first aspect. Thereby, when the fluid to be measured is not filled in the flow path in which the flow rate measuring unit is installed, it is possible to reduce the flow rate error by stopping the measurement. Further, the reliability can be improved by displaying in this case.
[0014]
  Claim3The invention described is particularly claimed in claims 1 to2The described flow rate measuring means operates with electric power. Accordingly, the energy supply of the flow rate measuring means is electric power, thereby enabling easy measurement.
[0015]
  Claim4The invention described is particularly claimed in claims 1 to3The described flow rate measuring means uses ultrasonic waves. Thereby, measurement with little pressure loss is enabled by performing flow measurement with an ultrasonic wave.
[0016]
  Claim5The invention described is particularly claimed in claims 1 to4The described flow rate on-off valve is configured to be driven by electric power. As a result, an operation that minimizes the influence on the piping system, such as arbitrarily controlling the opening / closing speed of the flow rate on / off valve, can be realized.
[0018]
【Example】
  Embodiments of the present invention will be described below with reference to the drawings.
[0019]
  (Reference example 1)
  Reference example 1A flow rate measuring device according to the present invention will be described. FIG. 1 is a block diagram of a flow rate measuring apparatus showing the configuration of this embodiment.
[0020]
  In FIG. 1, a flow rate measuring unit 11 disposed in a flow path 10 through which a fluid to be measured flows, a flow rate on / off valve 12 installed upstream of the flow rate measuring unit 11, a control for controlling the flow rate measuring unit 11 and the flow rate on / off valve 12. Means 13 is provided, and the control means 13 is connected to a power source 14. There are various types of flow rate measuring means 11 such as a film type for gas measurement and an impeller type for liquid measurement. In this embodiment, an ultrasonic flow meter using electric power will be described as an example. There are electromagnetic and hot-wire systems in the system using electric power, but the same effect can be obtained by using these systems.
[0021]
  FIG. 2 shows a block diagram of the flow rate measuring means 11. In FIG. 2, the first vibrator 15 a and the second vibrator 15 b that transmit and receive the ultrasonic wave arranged in the flow path 10, the driving means 17 that drives the first vibrator 15 a, and the driving means 17 Control means 13 for outputting an operating measurement start signal, flow rate calculating means 16 for calculating the flow velocity of the fluid to be measured in the flow path 10 by receiving the output of the second vibrator 15b, and flow rate from the control means 15 The power supply control means 17 which controls power on / off to the calculation means 16 and the timer means 18 which manages a measurement time interval are provided.
[0022]
  The driving means 17 that receives the start signal from the control means 13 drives the first vibrator 15a with a pulse for a predetermined time, and the flow rate calculation means 16 receives the received signal from the second vibrator 15b and amplifies the signal. A receiving means 20, a timing detecting means 21 for determining a receiving timing using the signal, a delay means 22 for outputting an output of the timing detecting means 21 as a trigger signal of the driving means 17 with a predetermined delay time, and an ultrasonic wave The repeater 23 for measuring the number of operations of repeating the transmission / reception of ultrasonic waves again after the delay time by the delay unit 22 and stopping the operation at a predetermined number of times, and driving the first vibrator 15a by at least the drive unit 17 A time measuring means 24 for measuring the propagation time of the ultrasonic wave from the start to the operation stop of the repetitive means 23, and the value of the time measuring means 24 And calculating means 25 calculates the flow rate between the pair of transducers, then determine the flow rate, sampling adjusting unit 26 for adjusting the sampling interval, which is from the measuring stop means 27 for presenting the measurement.
[0023]
  Further, a switching means 28 is provided between the driving means 17 and the first vibrator 15a, and between the second vibrator 15b and the receiving means 20, and the first vibrator 15a and the second vibrator are used for transmitting and receiving ultrasonic waves. You may make it carry out alternately between 15b. When the switching means 28 alternately performs transmission and reception in this way, the respective propagation times of the fluid to be measured from upstream to downstream and from downstream to upstream are measured, the velocity v is obtained from (Equation 1), and the flow rate is calculated from the flow velocity. Can be requested. This method is widely used because the flow rate can be measured without being affected by the change in the speed of sound (the effective distance in the flow direction between ultrasonic sensors is L, and the measurement is performed from upstream to downstream.timeT1, measurement from downstream to upstreamtimeT2).
[0024]
  v = L / 2 ((1 / t1)-(1 / t2)) (Formula 1)
  Further, a signal is sent from the control means 17 to the valve drive means 12b in order to operate the flow rate on-off valve 12a. There are various types of on-off valves, which are manual valves. In the present embodiment, description will be made by taking an example of an electromagnetic valve or a motor valve that operates with electric power.
[0025]
  FIG. 3 shows a block diagram of a motor valve as an example of the valve. In FIG. 3, a valve driving means 12b made of a motor and a manual means 12d are connected to the valve 12a. 12c is a clutch plate.
[0026]
  FIG. 4 is a timing chart showing the operation of the flow rate measuring means 11 and the flow rate on-off valve 12.
[0027]
  The operation will be described with reference to FIGS. In FIG. 4, the flow rate measurement is performed until the time t0 because the flow rate on-off valve 12 is open. However, when the control means 13 sends a signal for closing the flow rate on / off valve 12 at time t0 as shown in FIG. 4B, the flow rate on / off valve 12 is closed at time t1 after a predetermined time has elapsed. After this, the fluid to be measured does not flow because the valve is closed. Therefore, the control means may change the measurement timing, which has been measured in the period T until t0, to the period T1 (T1> T0) as shown in FIG. 4 (c1). This saves power because the number of operations is reduced. More specifically, this is realized by increasing the period for outputting the start signal to the driving means.
[0028]
  When more detailed measurement is performed, the sampling adjustment means 26 is used, and when the flow rate on-off valve is closed, the sampling interval is accurately changed to T1. As a result, power can be reliably saved.
[0029]
  If the flow rate on / off valve 12 is closed as shown in FIG. 4 (c2), the control unit stops the flow rate measurement by the signal from the measurement stop unit 27 after the time t1. Further, a signal may be output to the power control means 18 to stop the power supply to the flow rate measuring means 16. As a result, the use of power can be stopped, so that energy saving can be realized.
[0030]
  Further, as shown in FIG. 4 (c3), since the operation of the fluid to be measured becomes unstable when the flow rate on / off valve 12 enters the closing operation, the control unit measures the flow rate by the signal from the measurement stop unit 27 at time t0. It will stop. Further, a signal may be output to the power control means 18 to stop the power supply to the flow rate measuring means 16. This uses electricityofThe stoppage can be quickened and the fluid measurement is stopped in a state where the fluid flow is unstable, so that energy saving and measurement error prevention can be realized.
[0031]
  In this way, handling of the measuring means is facilitated by using electric power for energy supply of the flow rate measuring means. Further, by performing the measurement with ultrasonic waves, the pressure loss of the flow path can be reduced as much as possible, and measurement from a minute flow rate to a large flow rate can be realized with a simple configuration.
[0032]
  Furthermore, the flow rate on / off valve is driven by electric power, so that it is easy to arbitrarily control the opening / closing speed, and the influence on the piping system can be reduced.
[0033]
  Further, by providing the manual means 12d of FIG. 3, it becomes possible to manually operate the on-off valve even if a problem occurs in the power supply system, and the reliability is further improved.
[0034]
  (Reference example 2)
  Reference example 2A flow rate measuring device according to the present invention will be described. FIG. 5 is a block diagram showing the configuration of the flow rate measuring means 16 of this embodiment.Reference example 1The difference is that a gain adjusting means 29 for adjusting the gain of the receiving means 20 and an offset adjusting means 30 for adjusting the offset from the result of the calculating means 25 are provided.
[0035]
  The operation will be described below with reference to FIG. When a closing signal is sent from the control means 13 to the flow rate on / off valve 12 at time t0 in FIG. 6, the closing is completed at t1. Thereafter, since the fluid to be measured does not flow, the flow rate measuring means 16 may adjust itself. First, the received signal from the second vibrator 15b may become smaller or larger due to various conditions such as aging and temperature characteristics. For this reason, the gain of the receiving means 20 needs to be changed. When the fluid to be measured is not flowing, the fluid measuring means 16 sends a driving signal from the driving means 17 to the first vibrator 15a and checks the reception level of the receiving means 20. Then, the control unit 13 performs reception adjustment using the gain adjustment unit 29 so as to obtain an optimum reception state. Specifically, the gain is adjusted so that the signal does not saturate and becomes the optimum detection level. This operation may be performed for a certain period from time t1 to t2 when the flow rate on / off valve 12 is closed, or between time t3 and t4 before the flow rate on / off valve 12 is opened. By adjusting the gain in this way, it becomes possible to perform measurement with an optimum gain when the flow rate on-off valve is opened next time and measurement is started.
[0036]
  Further, even if the flow rate on / off valve 12 is closed, the value of the calculation means 25 for calculating the flow rate by the signal from the time measuring means 24 may not be zero, and calculation may be performed such that there is a flow. This is because the offset of the measurement system has changed, and correction is required. Normally, it is difficult to perform correction when the fluid to be measured is flowing, but after time t1 in FIG. 6, the flow rate on-off valve 12 is closed and there is no flow. Therefore, if the flow rate measured at this time is corrected as an offset, an accurate zero flow rate can be obtained. Specifically, the flow rate obtained by the computing means 25 can be stored by the offset adjusting means 30, and the value can be adjusted as a correction term during normal measurement. The detection of the offset may be performed for a fixed time from time t1 to time t2 in FIG. 6 or during time t3 to time t4 before the flow rate on / off valve 12 is opened.
[0037]
  In order to reliably correct the zero flow rate, it is preferable to perform both of these operations. However, if only one of them is used, it is preferable to reduce the error when the fluid actually flows before opening. Thus, by accurately measuring and adjusting the zero flow rate when no fluid is flowing, it is possible to perform more accurate and optimal measurement than when the next measurement is started.
[0038]
  (Example1)
  Example 1A flow rate measuring device according to the present invention will be described. FIG. 7 is a block diagram showing the configuration of the flow rate measuring means 16 of this embodiment.Reference example 1The difference is that the first timer means 31 that operates when the flow rate on-off valve is closed, the second measurement stop means 32 that operates on the signal of the first timer means 31, and the constant after the flow on-off valve 12 is closed. The second timer means 33 that outputs a signal every time and the third timer means 34 that operates for a predetermined time after the flow rate on-off valve 12 is closed are provided.
[0039]
  The operation will be described below with reference to FIG. When a closing signal is sent from the control means 13 to the flow rate on / off valve 12 at time t0 in FIG. 8, the closing is completed at t1. Thereafter, the fluid to be measured should not flow through the flow path, but there is a possibility that the flow remains on the downstream side. Therefore, when the flow rate on / off valve 12 is closed, the control means 13 issues a signal to operate the first timer means 31. The first timer means starts operating from time t1 and continues operating until time t2 when a predetermined time T elapses. While the first timer unit 31 is operating, the control unit 13 continues to operate and the flow rate measurement unit 16 measures the flow rate. When the first timer means 31 reaches a predetermined time T, it sends a signal to the second measurement stop means. When the second measurement stop means 32 receives this signal, it requests the control means 13 to stop the flow rate measurement. As a result, the flow rate measurement is continued for a while after the flow rate valve 12 is closed, so even if the flow remains on the downstream side, it is accurately measured, and after the flow has stopped, the measurement is stopped to save energy. Can be realized.
[0040]
  Next, another operation will be described with reference to FIGS. When a closing signal is sent from the control means 13 to the flow rate on / off valve 12 at time t0 in FIG. 9, the closing is completed at t1. Thereafter, the fluid to be measured should not flow through the flow path, but there is a possibility that the stopper may be twisted or the cock may be opened because the fluid to be measured is desired downstream. Therefore, when the flow rate on / off valve 12 is closed, the control means 13 issues a signal to operate the second timer means 33. The second timer means outputs a signal at a constant time interval T2 after the flow rate on-off valve 12 is closed, and the control means 13 measures the flow rate every time it receives this signal. This time interval T2 may be much longer than the normal sampling time. Thereby, even after the flow rate on-off valve is closed, it is possible to detect that the use of the fluid to be measured is started on the downstream side by confirming the flow of the flow rate at regular intervals. When the flow is detected, the control means 13 can open the flow rate on-off valve 12 using the on-off valve driving means 12b to allow the fluid to flow, and the convenience for the user can be improved.
[0041]
  Next, another operation will be described with reference to FIGS. When a closing signal is sent from the control means 13 to the flow rate on / off valve 12 at time t0 in FIG. 10, the closing is completed at t1. It is usually unthinkable that the flow resumes frequently once the flow is gone. Therefore, when the flow rate on / off valve 12 is closed, the control means 13 issues a signal to operate the third timer means 34. The third timer means 34 turns on at a constant time interval Tx after the flow rate on-off valve 12 is closed. When the third timer means 34 is in the ON state, the control means 13 ignores the opening signal even if there is another opening signal since it has not yet been closed. For example, it cannot be opened at time t2 in FIG. After the third timer means 34 has passed a sufficiently long time Tx, for example, when there is a request for opening after the time T + ΔT in FIG. 10, the control means 13 opens the flow rate on-off valve 12. In this way, once the flow rate on-off valve is closed, it is not opened within a predetermined time, thereby affecting the piping system such as the measurement system and valve hunting phenomenon and heat generation due to frequent operation. It becomes possible to realize stable measurement over a long period of time by reducing the burden on the user.
[0042]
  (Reference example 3)
  Reference example 3A flow rate measuring device according to the present invention will be described. The block diagram showing the configuration of the flow rate measuring means 16 is the same as FIG.Reference example 1The difference is the method for closing and opening the flow rate valve.
[0043]
  The operation will be described with reference to FIG. When a closing signal is sent from the control means 13 to the flow rate on / off valve 12 at time t0 in FIG. 11, for example, a valve that can control the speed, such as a motor valve, slowly closes the flow rate on / off valve over time T4 until time t1. To do. This is because when the valve is suddenly closed, when the fluid to be measured is a liquid, a phenomenon such as a water hammer occurs in the piping system. Even in the case of gas, a sudden pressure change may occur. On the contrary, when the flow rate on / off valve 12 is opened, there is a user on the downstream side, and therefore it is necessary to supply the flow rate at a satisfactory rate. Therefore, the valve is opened at an early time indicated by time T5 from time t2 to t3 in FIG. Here, T5 << T4. This time can be easily realized by the control means 13 by voltage control or change in pulse rate. Thus, by optimizing the speed at the time of closing and opening of the flow rate on / off valve in consideration of the piping system, it becomes possible to operate comfortably without affecting the surroundings.
[0044]
  (Reference example 4)
  Reference example 4A flow rate measuring device according to the present invention will be described. FIG. 12 is a block diagram showing the configuration of the flow rate measuring means 16 of this embodiment.Reference example 1The difference is that a measurement state display means 35 for displaying the result of the calculation means 25 and an external input means 36 are provided so that the flow rate measurement can be stopped from the outside.
[0045]
  The operation will be described below with reference to FIG. If the operation of the flow rate measuring unit 16 is stopped by the control unit 13 after the flow rate on-off valve 12 is closed, the flow rate cannot be measured. However, from the user's point of view, it is often impossible to determine whether the fluid is flowing or the measurement is stopped. In particular, piping is usually not transparent and the inside cannot be seen, and even if it is visible, it is difficult to detect the flow. Therefore, it is useful for the user to indicate what state the operation of the flow rate measuring means 16 is. For this reason, the measurement state display means 35 is installed to clearly indicate whether measurement is being performed or measurement is stopped. As a result, the operation status of the flow rate measuring means is clarified and the user does not make a mistake in the operation, for example, it is possible to prevent misidentification such as a failure, so that no wasteful work is performed from the user to the device provider. I'm very happy.
[0046]
  Next, other operations will be described with reference to FIG. Normally, there is no inconvenience even if the flow rate measuring device opens and closes the internal flow rate switching valve 12 alone. However, if air is mixed in the upstream construction in the gas piping, or because the upstream construction is the same in the water piping. When turbid water is mixed, the flow rate is not integrated using these as effective fluids to be measured. Therefore, the control means 13 is provided with an external input means 36 and a communication means 37 connected thereto. If an unsatisfactory fluid to be measured flows due to an external signal, a signal is sent from the external input means 36 to the control means 13 via the communication means 37 in advance. When the control unit 13 receives a signal from the outside, the control unit 13 outputs a signal to the flow rate measuring unit 16 and temporarily stops the flow rate measurement. Then, after unnecessary fluid has flowed, flow measurement is resumed. Accordingly, it is possible to easily realize an operation such as not measuring the flow rate of unnecessary fluid.
[0047]
  (Reference Example 5)
  Reference Example 5A flow rate measuring device according to the present invention will be described. FIG. 13 is a block diagram showing the configuration of the flow rate measuring means 16 of this embodiment.Reference example 1The difference is that a second time measuring means 38 for measuring the daily time and a storage means 39 for storing a preset flow rate value are provided.
[0048]
  The operation will be described below with reference to FIG. As described in the conventional example, the fluid to be measured flows through the piping such as gas and water for only a few hours in 24 hours. For this reason, in the time zone when there is no flow rate, the flow rate measuring device can close the fluid on-off valve 12 and stop the operation of the flow rate measuring means 16 to reduce power consumption. This unused time zone is often not constant depending on the conditions of each user. Accordingly, the second time measuring means 38 sends a signal to the control means 13 at a predetermined time TT. When this signal is input, the control means 13 measures the flow rate using the flow rate measurement means 16 for the time ΔT2. If the measured flow rate at this time ΔT2 is equal to or less than a predetermined value, it may be determined that no fluid is used downstream. Therefore, the control means 13 closes the flow rate on / off valve 12 via the valve driving means 12b. After the valve is closed, the power supply to the flow rate measuring means 16 can be stopped. In this way, it is possible to reduce the possibility of causing an unnecessary fluid to be measured to flow downstream by confirming that there is no flow rate during a time when the flow rate is not being used so much and closing the flow rate on-off valve 12.
[0049]
  Next, other operations will be described. As described in the conventional example, the fluid to be measured flows through the piping such as gas and water for only a few hours in 24 hours. For this reason, the flow rate measuring means 16 measures the flow rate when there is no flow rate, and the second time measuring means 38 recognizes the daily usage pattern, and the time zone with less use is stored in the storage means 39. Is possible. Thereafter, while the time is being watched by the second time counting means 38, the control means 13 uses the flow rate measuring means 16 for a predetermined time ΔT2 at the time stored in the storage means 39, for example, the time TT in FIG. To measure the flow rate. If the measured flow rate at this time ΔT2 is equal to or less than a predetermined value, it may be determined that no fluid is used downstream. Therefore, the control means 13 closes the flow rate on / off valve 12 via the valve driving means 12b. After the valve is closed, the power supply to the flow rate measuring means 16 can be stopped. In this way, the time zone in which the flow rate is not frequently used is stored in the storage means 39 in advance, and the flow rate is measured at that time and the valve is closed, so that the flow rate is confirmed at a time when there is a high possibility that there is no flow rate. By closing the flow rate on-off valve 12, the possibility of flowing unnecessary fluid to be measured downstream can be reliably reduced.
[0050]
  (Example2)
  Example 2A flow rate measuring device according to the present invention will be described. FIG. 15 is a block diagram showing the configuration of the flow rate measuring means 16 of this embodiment.Reference example 1The difference is that a filling confirmation means 40 for confirming whether or not the fluid to be measured is filled in the flow path 10 is provided.
[0051]
  The operation will be described below with reference to FIG. It is difficult to measure an accurate flow rate if the fluid to be measured is not filled inside the flow path, whether it is an ultrasonic flow meter, an electromagnetic flow meter, or a hot-wire flow meter. Therefore, as shown in the present embodiment, the flow rate measurement is started after the fullness confirmation means 40 confirms whether or not the measured flow channel is filled in the flow channel. For example, the fullness confirmation means 40 may be a timer such as a timer that automatically outputs a confirmation signal after a fixed time has passed after the flow measuring device is installed, or a signal that is manually transmitted. Further, when the fluid is measured by ultrasonic waves, the propagation speed changes when the quality of the fluid changes. Therefore, if a value other than the predicted value calculated in advance using the output of the calculation means 25 is obtained, the fluid changes in quality. Or in the case of a liquid, or in the case of a liquid, it can be determined that the air is not in a steady state. Therefore, as the fullness confirmation means 40, it is possible to estimate the state of the fluid inside the flow path using the value itself of the calculation means 25. In this way, when it is determined that the state of the flow path is not filled with the fluid to be measured, the control means 13 can stop the operation of the flow rate measuring means 16 and reduce the flow rate error. . In addition, in the case of a fluid to be measured that is charged, the flow rate is measured only when the correct fluid flows, so that the reliability can be improved and the satisfaction can be obtained for the user and the fluid supplier. Can measure.
[0052]
【Effect of the invention】
  As is apparent from the above description, the flow measurement device of the present invention provides the following effects.
[0053]
  (1) Energy saving can be realized by reducing the measurement frequency while the flow control valve is closed.
[0054]
  (2) Energy saving can be realized by changing the sampling time of the flow rate measuring means.
[0055]
  (3) Energy saving and malfunction can be prevented by stopping the flow rate measuring means while the flow rate control valve is closed.
[0056]
  (4) When the flow rate on / off valve starts the closing operation, the flow of fluid becomes non-uniform, so that the flow rate measurement can be stopped to prevent measurement errors.
[0057]
  (5) By adjusting the gain of the flow rate measuring means when the flow rate is not flowing, it is possible to perform the optimum measurement from the start of the next measurement.
[0058]
  (6) By measuring and adjusting the zero flow rate accurately when the flow rate is not flowing, it is possible to perform optimum measurement from the start of the next measurement.
[0059]
  (7) Even if the flow rate on / off valve is closed, the flow may be generated on the downstream side for a while, so that a precise supply flow rate can be obtained by measuring the flow rate for a certain period of time with a timer.
[0060]
  (8) It is possible to detect that the use has started on the downstream side by confirming the flow of the flow rate every certain time after the flow rate on-off valve is closed.
[0061]
  (9) Once the flow rate on-off valve is closed, it is not opened within a predetermined time, thereby reducing the influence on the piping system due to hunting or the like and the burden on the drive system.
[0062]
  (10) When closing the flow rate on-off valve, it operates at a speed that minimizes pressure fluctuations in the piping system. At the time of opening, it operates at a speed that does not affect the measurement accuracy, so that the valve can be opened and closed without affecting the surroundings. It can be carried out.
[0063]
  (11) By displaying the operating status of the flow rate measuring means, it is possible to prevent misidentification as a failure.
[0064]
  (12) Since the operation of the flow rate measuring means can be controlled from the outside, it is possible to easily perform an operation such as not measuring the flow rate of unnecessary fluid.
[0065]
  (13) When there is no flow rate in a time zone where the flow rate is not used much on a daily basis, unnecessary flow can be stopped by closing the flow rate on-off valve.
[0066]
  (14) A time zone in which the flow rate is not used on a daily basis is stored, and if there is no flow rate in that time zone, the flow rate on-off valve can be closed to stop unnecessary supply.
[0067]
  (15) When the fluid to be measured is not filled in the flow path in which the flow rate measuring unit is installed, the flow rate error can be reduced by stopping the measurement.
[0068]
  Further, by displaying in this case, the reliability can be further improved.
[0069]
  (16) The energy supply of the flow rate measuring means uses electric power to enable easy handling.
[0070]
  (17) Measurement with less pressure loss is possible by performing flow rate measurement with ultrasonic waves.
[0071]
  (18) By operating the flow rate on / off valve with electric power, it is possible to realize an operation that minimizes the influence on the piping system, such as arbitrarily controlling the opening / closing speed.
[0072]
  (19) By providing means that can manually operate the flow rate opening / closing valve, convenience can be improved because it is possible to operate even if a problem arises in the power supply system even when it is necessary to open and close urgently.
[Brief description of the drawings]
FIG. 1 of the present inventionReference example 1Block diagram of the entire flow measurement device
FIG. 2 is a block diagram of the flow rate measuring means of the flow rate measuring device.
FIG. 3 is a block diagram of a flow rate on / off valve of the flow rate measuring device.
FIG. 4 is a timing chart showing the operation of the flow rate measuring means of the flow rate measuring device.
FIG. 5 shows the present invention.Reference example 2Block diagram of flow rate measuring means
FIG. 6 is a timing chart showing the operation of the flow rate measuring means
[Fig. 7] of the present invention.Example 1Block diagram of flow rate measuring means
FIG. 8 is a timing chart showing the operation of the first timer means of the flow rate measuring means
FIG. 9 is a timing chart showing the operation of the second timer means of the flow rate measuring means.
FIG. 10 is a timing chart showing the operation of the third timer means of the flow rate measuring means.
FIG. 11 shows the present invention.Reference example 3Chart showing the operation of the flow rate on / off valve
FIG. 12 shows the present invention.Reference example 4Block diagram of flow rate measuring means
FIG. 13 shows the present invention.Reference Example 5Block diagram of flow rate measuring means
FIG. 14 is a timing chart showing the operation of the flow rate measuring means.
FIG. 15 is a block diagram of the flow rate measuring means in Embodiment 7 of the present invention.
FIG. 16 is an overall block diagram of a conventional ultrasonic current meter
[Explanation of symbols]
  10 Channel
  11 Flow rate measuring means
  12 Flow rate valve
  13 Control means
  14 Power supply
  26 Sampling adjustment means
  27 Measurement stop means
  29 Gain adjustment means
  30 Offset adjustment means
  31 First timer means
  32 Second measurement stop means
  33 Second timer means
  34 Third timer means
  35 Display means
  36 External input means
  38 Second timing means
  39 Memory means
  40 Charge confirmation means

Claims (5)

Flow rate measuring means for measuring the flow rate of the fluid to be measured flowing in the flow path using the propagation time difference of the ultrasonic wave, a flow rate opening / closing valve installed at least one of upstream or downstream of the flow rate measuring means, the flow rate measuring means, Comprising control means for controlling the flow rate on-off valve;
The flow rate measuring means measures the flow rate of the fluid to be measured even after the flow rate on-off valve is closed, and after the first time has elapsed, stops the measurement .
The control means does not open the on-off valve until after a second time longer than the first time elapses . Flow rate measuring device according to claim 1 wherein the flow measuring means, characterized in that does not perform measurement in the case where the fluid to be measured is not filled in the flow path. The flow rate measuring means flow rate measuring apparatus according to any one of claims 1-2, characterized in that it uses the power. The flow rate measuring means flow rate measuring device according to any one of claims 1 to 3, characterized in that using ultrasound. The flow-off valve flow rate measuring device according to any one of claims 1 to 4, characterized in that is driven by the power.

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