JP2021148693A - Flowmeter and controller - Google Patents

Abstract

To make it possible to determine that the state in which a measured value of a flow rate is output after a valve is closed is due to erroneous measurement of a flowmeter.SOLUTION: A first determination unit 104 first determines whether a measured value is larger than a set reference value from a control time point a predetermined time after when a receiving unit 103 receives a control signal. As a result of the determination, when the measured value is larger than the reference value, the first determination unit 104 determines in a first dead zone whether the measured value corresponds to a value when the flow rate of fluid is zero. A second determination unit 105 first determines whether the measured value is larger than the reference value from the control time point. As a result of the determination, when the measured value is smaller than the reference value, the second determination unit 105 determines in a second dead zone whether the measured value corresponds to the value when the flow rate of fluid is zero. The second determination unit 105 makes the above-described determination in a set change period.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, after the valve is closed, the flow rate is measured by the flow meter and the measured value is output, which is actually caused by an erroneous measurement of the flow meter or due to a valve failure. It is not possible to determine whether the flow rate is occurring in. As described above, in the conventional technique, it cannot be determined that 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 the erroneous measurement of the flow meter. was there.

The present invention has been made to solve the above problems, and the state in which the measured value of the flow rate is output after the valve is closed is caused by an erroneous measurement of the flow meter. The purpose is to be able to judge.

The flow meter according to the present invention is a flow meter that measures the flow rate of a fluid to be measured flowing through a pipe, and has an output unit configured to output a 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. If the measured value is larger than the set reference value from the control time point after the predetermined time when the receiving unit receives the control signal, whether or not the measured value corresponds to the value when the flow rate of the fluid is zero. The first determination unit configured to determine in the first dead zone, and the receiving unit receives another second control signal different from the first control signal when the measured value is smaller than the reference value from the control time point. The change period up to is 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, and the change period is a second determination unit. In addition, when the measured value is determined to be a value corresponding to the time when the flow rate of the fluid is zero, a processing unit configured to set the measured value to zero is provided.

In one configuration example of the flow meter, the first determination unit is provided with a notification unit configured to notify the first determination unit 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. Further prepare.

In one configuration example of the flow meter, the notification unit notifies that an abnormality has occurred in the flow rate measurement.

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 measured value of the flow rate of the fluid flowing through the pipe with a flow meter. The opening of the valve is determined by the stop unit configured to control If the measured value is larger than the set reference value from the control time after the predetermined time controlled to zero, it is determined in the first dead zone whether the measured value corresponds to the value when the flow rate of the fluid is zero. If the measured value is smaller than the reference value from the time of control, the flow rate of the fluid whose measured value is zero is zero during the change period until the valve opening is controlled to other than zero. The second determination unit is configured to determine whether or not the value corresponds to when the value is in the second dead zone, and the change period corresponds to the second determination unit when the measured value is zero when the flow rate of the fluid is zero. When it is determined that the value is to be measured, a processing unit configured to set the measured value to zero and an output unit configured to output the measured value are provided.

In one configuration example of the controller, if it is determined that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero, the first determination unit is further provided with a notification unit configured to notify this fact. Be prepared.

In one configuration example of the controller, the notification unit notifies that an abnormality has occurred in the flow rate measurement.

As described above, according to the present invention, when the measured value of the measured flow rate is larger than the reference value, the first determination unit determines in the first dead zone, and when the measured value is smaller than the reference value, the first Since the determination is made in the second dead zone in the 2 determination unit, it can be determined that the state in which the measured value of the flow rate is output after the valve is closed is caused by the erroneous measurement of the flow meter.

FIG. 1 is a configuration diagram showing a configuration of a flow meter according to a first embodiment of the present invention. FIG. 2 is a configuration diagram showing a configuration of a controller according to a second embodiment of the present invention. FIG. 3 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 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, and a processing unit 106.

The output unit 101 outputs the measured value of the flow rate. For example, the output unit 101 displays and outputs the measured value. The displayed and output measured values can be visually recognized by the user. Further, the output unit 101 outputs, for example, 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 makes the opening degree of the valve 121 that adjusts the flow rate of the fluid flowing through the pipe 151 zero. The receiving unit 103 also receives the control signal sent from the controller 122 to the valve 121.

The first determination unit 104 first determines whether or not the measured value is larger than the set reference value from the control time point after a predetermined time when the receiving unit 103 receives the control signal. As a result of this determination, when the measured value is larger than the reference value, 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 time of control, the second determination unit 105 first determines whether or not the measured value is larger than the reference value. As a result of this determination, when the measured value is smaller than the reference value, 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. The second determination unit 105 carries out the above-mentioned determination during the change period until the receiving unit 103 receives another second control signal different from the first control signal.

The processing unit 106 sets the measured value to zero when the second determination unit 105 determines that the measured value corresponds to a value when the flow rate of the fluid is zero during the change period.

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. As a result, the processing unit 106 sets the measured value to zero, and the output unit 101 displays and outputs zero as the measured value.

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. As a result, the processing unit 106 does not set the measured value to zero. Further, the output unit 101 displays and outputs a non-zero measured value.

As described above, by confirming the measured value displayed and output by the output unit 101, for example, in the case of the notification described with reference to FIG. 2A, zero is displayed and output as the measured value, so that the flow meter 100 (sensor) 111) It is a temporary pressure fluctuation on the upstream side, and it can be judged that it is not abnormal.

On the other hand, in the case of the notification described with reference to FIG. 2B, a non-zero measured value is displayed and output. By checking this, for example, when the flow rate is actually generated due to the failure of the valve 121, or It can be determined that some kind of abnormality has occurred, such as when an abnormality has occurred in the flow rate measurement such as the zero point of the sensor 111 being shifted.

A notification unit 107 may be further provided to automate the above-mentioned determination. The notification unit 107 notifies the first determination unit 104 of the fact 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. 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, the notification unit 107 notifies the first determination unit 104 that an abnormality has occurred in the measurement of the flow rate. The notification unit 107 notifies the user, for example, by displaying on the display device that an abnormality has occurred.

As described above, according to the first embodiment, when the measured value of the flow rate measured by the flow meter 100 (sensor 111) is larger than the reference value, the first determination unit 104 determines in the first dead zone. .. On the other hand, when the measured value of the flow rate measured by the flow meter 100 is smaller than the reference value, the second determination unit 105 determines in the second dead zone. After the control point, the flow rate should be zero. On the other hand, when the measured value is larger than the reference value, it can be assumed that the cause is an erroneous measurement of the flow meter 100.

According to the first embodiment, since the second determination unit determines the change period in the second dead zone, it can be determined whether or not the state in which the flow rate is measured after the valve is closed is caused by an abnormality. Will be. According to the first embodiment, after the valve is closed, the measured value of the flow rate becomes 0 in the normal case (when there is no abnormality), and the measured value of the flow rate which is not 0 is output when there is an abnormality. The presence or absence of abnormality can be determined. According to the first embodiment, it is possible to prevent the measured value of the flow rate other than 0 from being output even though the fluid does not actually flow downstream from the valve.

Further, the notification unit 107 notifies the occurrence of the abnormality by the determination by the first determination unit 104 that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero. Therefore, even with this notification, the state in which the measured value of the flow rate is output after the valve 121 is closed is caused by an erroneous measurement of the flow meter 100, such as a shift of the zero point of the sensor 111. Can be judged.

[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 an output unit 206.

The stop unit 201 controls the opening degree of the valve 222 to zero. 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 first determines whether or not the measured value is larger than the set reference value from the control time point after a predetermined time in which the opening degree of the valve 222 is controlled to zero by the stop unit 201. As a result of this determination, when the measured value is larger than the reference value, the first determination unit 203 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 time of control, the second determination unit 204 first determines whether or not the measured value is larger than the reference value. As a result of this determination, when the measured value is smaller than the reference value, 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. The second determination unit 204 carries out the above-mentioned determination during the set change period.

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 output unit 206 outputs the measured value. For example, the output unit 206 displays and outputs the measured value. The displayed and output measured values can be visually recognized by the user.

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. As a result, the processing unit 205 sets the measured value to zero, and the output unit 206 displays and outputs zero as the measured value.

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. As a result, the processing unit 205 does not set the measured value to zero. Further, the output unit 206 displays and outputs a non-zero measured value.

As described above, by confirming the measured value displayed and output by the output unit 206, for example, in the case of the notification described with reference to FIG. 2A, zero is displayed and output as the measured value, so that it is upstream from the flow meter 221. It is a temporary pressure fluctuation on the side, and it can be judged that it is not abnormal.

On the other hand, in the case of the notification described with reference to FIG. 2B, a non-zero measured value is displayed and output. By checking this, for example, when the flow rate is actually generated due to the failure of the valve 121, or It can be determined that some kind of abnormality has occurred, such as when an abnormality has occurred in the flow rate measurement such as the zero point of the sensor 111 being shifted.

A notification unit 207 may be further provided to automate the above-mentioned determination. When the notification unit 207 determines to the first determination unit 203 that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero, the notification unit 207 notifies the first determination unit 203 to that effect. 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, the notification unit 207 notifies the first determination unit 203 that an abnormality has occurred in the measurement of the flow rate. The notification unit 207 notifies the user, for example, by displaying on the display device that an abnormality has occurred.

As described above, according to the second embodiment, when the measured value of the flow rate measured by the flow meter 221 is larger than the reference value, the first determination unit 203 determines in the first dead zone. On the other hand, when the measured value of the flow rate measured by the flow meter 221 is smaller than the reference value, the second determination unit 204 determines in the second dead zone. After the control point, the flow rate should be zero. On the other hand, when the measured value is larger than the reference value, it can be assumed that the cause is an erroneous measurement of the flow meter 221.

According to the second embodiment, since the second determination unit determines the change period in the second dead zone, it can be determined whether or not the state in which the flow rate is measured after the valve is closed is caused by an abnormality. Will be. According to the second embodiment, after the valve is closed, the measured value of the flow rate becomes 0 in the normal case (when there is no abnormality), and the measured value of the flow rate which is not 0 is output when there is an abnormality. The presence or absence of abnormality can be determined. According to the second embodiment, it is possible to prevent the measured value of the flow rate other than 0 from being output even though the fluid does not actually flow downstream from the valve.

Further, the notification unit 207 notifies the occurrence of the abnormality by the determination by the first determination unit 203 that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero. Therefore, even with this notification, it is determined that the state in which the measured value of the flow rate is output after the valve 222 is closed is caused by an erroneous measurement of the flow meter 221 such as a shift of the zero point. can.

As shown in FIG. 3, 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, when the measured value of the measured flow rate is larger than the reference value, the first determination unit determines in the first dead zone, and when the measured value is smaller than the reference value, Since the second determination unit determines in the second dead zone, it can be determined that the state in which the measured value of the flow rate is output after the valve is closed is caused by the erroneous measurement of the flow meter.

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 judgment unit, 105 ... Second judgment unit, 106 ... Processing unit, 107 ... Notification unit, 111 ... Sensor, 121 ... Valve, 122 ... controller, 151 ... piping, 200 ... controller, 201 ... stop unit, 202 ... storage unit, 203 ... first judgment unit, 204 ... second judgment unit, 205 ... processing unit, 206 ... output unit, 207 ... Notification 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.
If the measured value is larger than the set reference value from the control time point after the predetermined time when the receiving unit receives the control signal, whether the measured value corresponds to the value when the flow rate of the fluid is zero. With the first determination unit configured to determine in the first dead zone,
When the measured value is smaller than the reference value from the control time point, the measured value is a fluid during the change period until the receiving unit receives another second control signal different from the first control signal. A second determination unit configured to determine whether or not the value corresponds to when the flow rate is zero in the second dead zone, and
The change period includes a processing unit configured to set the measured value to zero when the measured value is determined to be a value corresponding to the time when the flow rate of the fluid is zero. Flowmeter. In the flow meter according to claim 1,
The first determination unit is further provided with a notification unit configured to notify that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero. Flowmeter. In the flow meter according to claim 2,
The notification unit is a flow meter characterized in that it notifies that an abnormality has occurred in the measurement of the flow rate. A controller that controls the opening degree of a valve that adjusts the flow rate of fluid flowing through a pipe based on the measured value 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
When the measured value is larger than the set reference value from the control time after a predetermined time when the opening degree of the valve is controlled to zero by the stop portion, the measured value corresponds to when the flow rate of the fluid is zero. A first determination unit configured to determine whether or not the value is to be measured in the first dead zone, and
If the measured value is smaller than the reference value from the control time point, is the change period until the valve opening degree is controlled to other than zero a value corresponding to the measured value when the fluid flow rate is zero? A second determination unit configured to determine whether or not it is in the second dead zone, and
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.
A controller including an output unit configured to output the measured value. In the controller according to claim 4.
The first determination unit is further provided with a notification unit configured to notify that the measured value is not a value corresponding to the time when the flow rate of the fluid is zero. controller. In the controller according to claim 5.
The notification unit is a controller characterized in that it notifies that an abnormality has occurred in the measurement of the flow rate.

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