JP2021148487A - Flowmeter and controller - Google Patents

Abstract

To make it possible to determine whether the state in which a measured value of a flow rate is output after a valve is closed is due to an abnormality.SOLUTION: A first determination unit 104 determines in a first dead zone whether a measured value corresponds to a value when the flow rate of fluid is zero from a control time point a predetermined time after when a receiving unit 103 receives a control signal. A second determination unit 105 determines in a second dead zone whether a change period of a time set from the control time point corresponds to a value when the measured value corresponds to the value when the flow rate of fluid is zero from the control time point. When the first determination unit 104 determines that the measured value does not correspond to the value when the flow rate of fluid is zero during the change period, a notification unit 107 notifies it.SELECTED DRAWING: Figure 1

Description

The present invention relates to a flow meter and a controller.

In industrial furnaces, boilers, air-conditioning heat source equipment, etc., fluid is required to be supplied at a set flow rate. For such control, various flow meters have been developed for accurately measuring the flow rate of the fluid flowing through the pipe. The controller controls the opening of the valve based on the measured value measured and output by the flow meter to control the flow rate of the fluid. In such control, the pipe may be blocked by a valve in order to reduce the flow rate of the fluid flowing through the pipe to zero, if necessary. In this state, the flow meter measurement result should be zero. However, in reality, the flow meter may output a non-zero measured value of the flow rate due to drift of the sensor of the flow meter even though the fluid does not flow in the pipe.

In response to the above problems, when the valve is closed, the flow rate of the fluid is measured by the flow meter or erroneously measured, and even if the measured value is output, the flow rate is forced to zero. A meter has been proposed (see Patent Document 1).

Japanese Patent No. 5101581

However, in the above-mentioned technique, the state in which the flow rate is measured by the flow meter and the measured value is output after the valve is closed is a temporary pressure fluctuation on the upstream side of the flow meter, and is not abnormal. It is not possible to determine whether it is an abnormal case such as an erroneous measurement of the above or an actual flow rate due to a valve failure. As described above, in the conventional technique, there is a problem that it cannot be determined whether or not the state in which the flow rate is measured by the flow meter and the measured value is output after the valve is closed is caused by an abnormality.

The present invention has been made to solve the above problems so that it can be determined whether or not the state in which the measured value of the flow rate is output after the valve is closed is caused by an abnormality. The purpose is to.

The flow meter according to the present invention is a flow meter that measures the flow rate of the fluid to be measured flowing through the pipe, and has an output unit configured to output the measured value of the flow rate, a first dead zone, and a first dead band. A storage unit configured to store a more enlarged second dead zone, and a receiving unit configured to receive a control signal that makes the opening of the valve that regulates the flow rate of the fluid flowing through the pipe zero. , A first determination configured to determine in the first dead zone whether or not the measured value corresponds to when the flow rate of the fluid is zero from the control time point after a predetermined time when the receiving unit receives the control signal. A second determination unit configured to determine whether or not the measured value corresponds to a value when the flow rate of the fluid is zero in the second dead zone for the unit and the change period set after the control time. And, during the change period, when the second determination unit determines that the measured value is a value corresponding to when the flow rate of the fluid is zero, the processing unit configured to set the measured value output by the output unit to zero. And, during the change period, the first determination unit is provided with a notification unit configured to notify that the measured value is not a value corresponding to when the flow rate of the fluid is zero.

In one configuration example of the flow meter, the reference time in which the determination period in which the measured value is determined not to correspond to the value when the flow rate of the fluid is zero is set in the first determination unit in the change period. If it is longer, an abnormality determination unit for determining that an abnormality has occurred is further provided, and the notification unit notifies the determination result of the abnormality determination unit.

In one configuration example of the flow meter, the abnormality determination unit sets the determination period in the first determination unit during the change period in which the measurement value is determined not to correspond to the value when the flow rate of the fluid is zero. If it is shorter than the specified reference time, it is judged that there is no abnormality.

The controller according to the present invention is a controller that controls the opening degree of a valve that adjusts the flow rate of the fluid flowing through the pipe based on the value measured by the flow meter of the flow rate of the fluid flowing through the pipe, and the opening degree of the valve is set to zero. The opening of the valve is reduced to zero by the stop unit configured to control the flow rate, the first dead zone, the storage unit configured to store the second dead zone expanded from the first dead zone, and the stop portion. A first determination unit configured to determine in the first dead zone whether or not the measured value of the flow rate corresponds to when the flow rate of the fluid is zero from the control time point after the controlled predetermined time, and the control time point. The later set change period includes a second determination unit configured to determine in the second dead zone whether or not the measured value corresponds to when the flow rate of the fluid is zero, and the change period is , The second determination unit determines that the measured value corresponds to a value when the flow rate of the fluid is zero, the processing unit is configured to set the measured value to zero, and the first determination unit during the change period. In addition, when it is determined that the measured value does not correspond to the value when the flow rate of the fluid is zero, a notification unit configured to notify this fact is provided.

In one configuration example of the above controller, in the change period, the determination period in which the measured value is determined not to correspond to the value when the flow rate of the fluid is zero is set in the first determination unit from the set reference time. If it is long, an abnormality determination unit for determining that an abnormality has occurred is further provided, and the notification unit notifies the determination result of the abnormality determination unit.

In one configuration example of the controller, in the change period, the first determination unit is set with a determination period in which the measured value is determined not to correspond to the value when the flow rate of the fluid is zero. If it is shorter than the reference time, it is judged that there is no abnormality.

As described above, according to the present invention, using the first dead zone and the second dead zone expanded from the first dead zone, it is determined whether or not the measured value corresponds to the value when the flow rate of the fluid is zero. Therefore, it can be determined whether or not the state in which the measured value of the flow rate is output after the valve is closed is caused by an abnormality.

FIG. 1 is a configuration diagram showing a configuration of a flow meter according to a first embodiment of the present invention. FIG. 2A is a characteristic diagram showing the relationship between the change in the measured value and each dead zone. FIG. 2B is a characteristic diagram showing the relationship between the change in the measured value and each dead zone. FIG. 3 is a configuration diagram showing a configuration of a controller according to a second embodiment of the present invention. FIG. 4 is a configuration diagram showing a hard wafer configuration of a flow meter and a controller according to an embodiment of the present invention.

[Embodiment 1]
First, the flow meter 100 according to the embodiment of the present invention will be described with reference to FIG. The flow meter 100 measures the flow rate of the fluid to be measured flowing through the pipe 151 by using the sensor 111. The opening degree of the valve 121 that adjusts the flow rate of the fluid flowing through the pipe 151 is controlled by the controller 122 based on the measured value of the flow rate measured by the flow meter 100.

For example, the sensor 111 includes a temperature measuring unit and a heater provided in contact with the outer wall of the pipe 151. The sensor 111 is a well-known thermal flow sensor, and the heater is set so that the difference between the temperature of the heater and the temperature of the fluid at a position not affected by the heat of the heater becomes the set set temperature difference. The sensor value corresponding to the state of heat diffusion in the fluid heated by the heater during driving is output. As is well known, the sensor values mentioned above correlate with the flow rate of the fluid. The flow meter 100 calculates the flow rate based on the sensor value to obtain the measured value.

The flow meter 100 includes an output unit 101, a storage unit 102, a receiving unit 103, a first determination unit 104, a second determination unit 105, a processing unit 106, and a notification unit 107.

The output unit 101 outputs the measured value of the flow rate. The output unit 101 outputs the measured value to the controller 122. The storage unit 102 stores the first dead zone and the second dead zone expanded from the first dead zone.

The receiving unit 103 receives a control signal that sets the opening degree of the valve 121 that adjusts the flow rate of the fluid flowing through the pipe 151 to zero (0). The receiving unit 103 also receives the control signal sent from the controller 122 to the valve 121.

The first determination unit 104 determines in the first dead zone whether or not the measured value corresponds to a value when the flow rate of the fluid is zero from the control time point after a predetermined time when the reception unit 103 receives the control signal. The second determination unit 105 determines in the second dead zone whether or not the measured value corresponds to a value when the flow rate of the fluid is zero during the change period set from the control time point.

When the second determination unit 105 determines that the measured value corresponds to a value when the flow rate of the fluid is zero, the processing unit 106 sets the measured value output by the output unit 101 to zero. The notification unit 107 notifies the first determination unit 104 of the change period when it is determined that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero.

For example, when the measured value changes as shown in FIG. 2A, the value from the control time point t1 to the time point t2 after a predetermined time from the time point t0 when the control signal is received is smaller than the first dead zone. Both the first determination unit 104 and the second determination unit 105 determine that the measured value corresponds to a value when the flow rate of the fluid is zero.

On the other hand, between the time point t2 and the time point t3, the value is smaller than the second dead zone, but the value is larger than the first dead band. Although it is determined that the value corresponds to when it is zero, the first determination unit 104 determines that the measured value is not a value corresponding to when the flow rate of the fluid is zero.

When the measured value changes as described above, the notification unit 107 displays, for example, a warning flag that is “ON” from time t2 to time t3 by using a display device as a notification. Further, the notification unit 107 outputs a digital signal corresponding to this warning flag as a notification.

Further, for example, when the measured value is changed as shown in FIG. 2B, the measured value is smaller than the second dead zone but larger than the first dead band from t0 when the control signal is received. The state of being is continuing. In this case, the notification unit 107 uses a display device to display, for example, a warning flag that is continuously “ON” from the control time point t1 as a notification. Further, the notification unit 107 outputs a digital signal corresponding to this warning flag as a notification.

By confirming the notification by the notification unit 107 as described above, for example, in the case of the notification described with reference to FIG. Since the determination period in which it is determined not to be present is short, it can be determined that the pressure fluctuation is temporary on the upstream side of the flow meter 100 (sensor 111) and is not abnormal. On the other hand, in the case of the notification described with reference to FIG. 2B, the first determination unit 104 has a long determination period in which the measurement value is determined not to correspond to the value when the flow rate of the fluid is zero. Therefore, for example, a valve. It is judged that some kind of abnormality has occurred, such as when the flow rate is actually generated due to the failure of 121, or the flow rate measurement is abnormal such as the zero point of the sensor 111 is shifted. Can be done.

An abnormality determination unit 108 may be further provided in order to automate the determination described above. In the change period, the abnormality determination unit 108 determines that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero in the first determination unit 104, and the determination period is shorter than the set reference time. If so, it is judged that it is not abnormal. The notification unit 107 notifies the determination result of the abnormality determination unit 108.

Further, the abnormality determination unit 108 sets a reference time in which the determination period in which the measurement value is determined not to correspond to the value when the flow rate of the fluid is zero is set in the first determination unit 104 in the change period. If it is longer, it is judged that an abnormality has occurred. The notification unit 107 notifies the determination result of the abnormality determination unit 108.

As described above, according to the first embodiment, whether or not the measured value corresponds to the value when the flow rate of the fluid is zero by using the first dead zone and the second dead zone expanded from the first dead zone. Therefore, it becomes possible to determine whether or not the state in which the measured value of the flow rate is output after the valve is closed is caused by an abnormality.

[Embodiment 2]
Next, the controller 200 according to the embodiment of the present invention will be described with reference to FIG. The controller 200 controls the opening degree of the valve 222 that adjusts the flow rate of the fluid flowing through the pipe 151 based on the measured value of the flow rate of the fluid flowing through the pipe 151 by the flow meter 221.

The controller 200 includes a stop unit 201, a storage unit 202, a first determination unit 203, a second determination unit 204, a processing unit 205, and a notification unit 206.

The stop unit 201 controls the opening degree of the valve 222 to zero (0). The storage unit 202 stores the first dead zone and the second dead zone expanded from the first dead zone. The first determination unit 203 determines whether or not the measured value of the flow rate corresponds to the value when the flow rate of the fluid is zero from the control time point after a predetermined time when the opening degree of the valve 222 is controlled to zero by the stop unit 201. Judgment is made in the first dead zone. The second determination unit 204 determines in the second dead zone whether or not the measured value corresponds to a value when the flow rate of the fluid is zero during the change period set from the control time point.

The processing unit 205 sets the measured value to zero when the second determination unit 204 determines that the measured value corresponds to a value when the flow rate of the fluid is zero during the change period. The notification unit 206 notifies the first determination unit 203 of the change period when it is determined that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero.

For example, when the measured value changes as shown in FIG. 2A, the value from the control time point t1 to the time point t2 after a predetermined time from the time point t0 when the control signal is received is smaller than the first dead zone. Both the first determination unit 203 and the second determination unit 204 determine that the measured value corresponds to a value when the flow rate of the fluid is zero.

On the other hand, between the time point t2 and the time point t3, the value is smaller than the second dead zone, but the value is larger than the first dead band. Although it is determined that the value corresponds to when it is zero, the first determination unit 203 determines that the measured value is not a value corresponding to when the flow rate of the fluid is zero.

When the measured value changes as described above, the notification unit 206 displays, for example, a warning flag that is “ON” from time t2 to time t3 by using a display device as a notification. Further, the notification unit 206 outputs a digital signal corresponding to this warning flag as a notification.

Further, for example, when the measured value is changed as shown in FIG. 2B, the measured value is smaller than the second dead zone but larger than the first dead band from t0 when the control signal is received. The state of being is continuing. In this case, the notification unit 206 displays, for example, a warning flag that is continuously “ON” from the control time point t1 by using a display device as a notification. Further, the notification unit 206 outputs a digital signal corresponding to this warning flag as a notification.

By confirming the notification by the notification unit 206 as described above, for example, in the case of the notification described with reference to FIG. Since the determination period in which it is determined that the fluid is not present is short, it can be determined that the pressure fluctuation is temporary on the upstream side of the flow meter 221 and is not abnormal. On the other hand, in the case of the notification described with reference to FIG. 2A, the first determination unit 203 has a long determination period in which the measured value is determined not to correspond to the value when the flow rate of the fluid is zero. Therefore, for example, a valve. It is judged that some kind of abnormality has occurred, such as when the flow rate is actually generated due to the failure of 222, or when there is an abnormality in the flow rate measurement such as the zero point of the flow meter 221 is shifted. be able to.

An abnormality determination unit 207 may be further provided in order to automate the determination described above. In the change period, the abnormality determination unit 207 determines that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero in the first determination unit 203, and the determination period is shorter than the set reference time. If so, it is judged that it is not abnormal. The notification unit 206 notifies the determination result of the abnormality determination unit 207.

Further, the abnormality determination unit 207 sets a reference time in which a determination period in which the measurement value is determined not to correspond to the value when the flow rate of the fluid is zero is set in the first determination unit 203 during the change period. If it is longer, it is judged that an abnormality has occurred. Notification unit 206? ?? ?? Notify the judgment result of.

As described above, also in the second embodiment, whether or not the measured value corresponds to the value when the flow rate of the fluid is zero by using the first dead zone and the second dead zone expanded from the first dead zone. Therefore, it becomes possible to determine whether or not the state in which the measured value of the flow rate is output after the valve is closed is caused by an abnormality.

As shown in FIG. 4, the flow meter and the controller according to the above-described embodiment include a CPU (Central Processing Unit) 301, a main storage device 302, an external storage device 303, and a network connection device 304. It is also possible to realize each of the above-mentioned functions by operating the CPU 301 (execution of the program) by the program expanded in the main storage device 302 as a computer device provided with the above. The network connection device 304 connects to the network 305. In addition, each function can be distributed to a plurality of computer devices.

As described above, according to the present invention, using the first dead zone and the second dead zone expanded from the first dead zone, it is determined whether or not the measured value corresponds to the value when the flow rate of the fluid is zero. Since the determination is made, it becomes possible to determine whether or not the state in which the measured value of the flow rate is output after the valve is closed is caused by an abnormality.

The present invention is not limited to the embodiments described above, and many modifications and combinations can be carried out by a person having ordinary knowledge in the art within the technical idea of the present invention. That is clear.

100 ... Flowmeter, 101 ... Output unit, 102 ... Storage unit, 103 ... Reception unit, 104 ... First determination unit, 105 ... Second determination unit, 106 ... Processing unit, 107 ... Notification unit, 108 ... Abnormality determination unit, 111 ... sensor, 121 ... valve, 122 ... controller, 151 ... piping, 200 ... controller, 201 ... stop unit, 202 ... storage unit, 203 ... first determination unit, 204 ... second determination unit, 205 ... processing unit, 206 ... Notification unit, 207 ... Abnormality judgment unit, 221 ... Flow meter, 222 ... Valve.

Claims (6)

A flow meter that measures the flow rate of the fluid to be measured flowing through the pipe.
An output unit configured to output measured flow rates and
A storage unit configured to store the first dead zone and the second dead zone expanded from the first dead zone, and
A receiver configured to receive a control signal that reduces the opening of the valve that regulates the flow rate of fluid flowing through the pipe to zero.
From the control time point after a predetermined time when the receiving unit receives the control signal, it is configured in the first dead zone to determine whether or not the measured value corresponds to a value when the flow rate of the fluid is zero. 1 Judgment unit and
The change period set from the control time point includes a second determination unit configured to determine whether or not the measured value corresponds to a value when the flow rate of the fluid is zero in the second dead zone.
The change period is configured such that when the second determination unit determines that the measured value corresponds to a value when the flow rate of the fluid is zero, the measured value output by the output unit is set to zero. Processing unit and
During the change period, the first determination unit is provided with a notification unit configured to notify that the measured value is not a value corresponding to when the flow rate of the fluid is zero. Flowmeter. In the flow meter according to claim 1,
In the change period, if the determination period in which the measurement value is determined by the first determination unit to be not a value corresponding to when the fluid flow rate is zero is longer than the set reference time, it is abnormal. It is further equipped with an abnormality judgment unit that determines that
The notification unit is a flow meter characterized in that the determination result of the abnormality determination unit is notified. In the flow meter according to claim 2,
In the change period, the abnormality determination unit has a reference time in which a determination period in which the measurement value is determined not to correspond to a value when the flow rate of the fluid is zero is set in the first determination unit. A flow meter characterized in that if it is shorter, it is judged that it is not abnormal. A controller that controls the opening degree of a valve that adjusts the flow rate of the fluid flowing through the pipe based on the value measured by the flow meter of the flow rate of the fluid flowing through the pipe.
A stop unit configured to control the opening of the valve to zero,
A storage unit configured to store the first dead zone and the second dead zone expanded from the first dead zone, and
From the control time point after a predetermined time when the opening degree of the valve is controlled to zero by the stop portion, it is determined in the first dead zone whether or not the measured value of the flow rate corresponds to the value when the flow rate of the fluid is zero. The first judgment unit configured as
The change period set from the control time point includes a second determination unit configured to determine whether or not the measured value corresponds to a value when the flow rate of the fluid is zero in the second dead zone.
The change period includes a processing unit configured to set the measured value to zero when the second determination unit determines that the measured value corresponds to a value when the flow rate of the fluid is zero.
During the change period, the first determination unit is provided with a notification unit configured to notify that the measured value is not a value corresponding to when the flow rate of the fluid is zero. controller. In the controller according to claim 4.
In the change period, if the determination period in which the measurement value is determined by the first determination unit to be not a value corresponding to when the fluid flow rate is zero is longer than the set reference time, it is abnormal. It is further equipped with an abnormality judgment unit that determines that
The notification unit is a controller that notifies the determination result of the abnormality determination unit. In the controller according to claim 5.
In the change period, the abnormality determination unit has a reference time in which a determination period in which the measurement value is determined not to correspond to a value when the flow rate of the fluid is zero is set in the first determination unit. A controller characterized in that if it is shorter, it is determined that it is not abnormal.

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