JPH11270488A - Automatic water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the erroneous operation of a pump by judging the abnormality of a flow rate detecting means or a pressure detecting means when a flow rate of more than a predetermined flow rate is detected and the output frequency of a variable speed operating means is detected to be the lowest frequency in a condition that the pump discharge pressure is controlled to be constant. SOLUTION: A flow rate discharged from a pump 15 is detected by a flow rate sensor 17 during the target pressure constant operation where the operating frequency of an inverter 16b is controlled so that the discharge pressure by a pressure sensor 20 mounted in a water supply pipe 18 agrees with the target pressure, to judge whether the detected flow rate is more than a predetermined flow rate or not. When the result of the judgement is YES, the output frequency of the operating current output from the inverter 16b to a motor 15m is detected by an output frequency detecting part 16c. When the result of the judgement is YES, it is judged that the flow rate sensor 17 or a pressure sensor is abnormal, and the operation of the pump 15 is focibly stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic water supply system for automatically operating a pump using an inverter, which is provided with a protection function for detecting an abnormality of a flow rate sensor or a pressure sensor and preventing a malfunction of the pump. Automatic water supply device.

[0002]

2. Description of the Related Art In recent years, a pump used in an automatic water supply device is controlled by an inverter to control the rotation speed of the pump so that the discharge pressure of the pump is kept constant. As described above, the pump used in the automatic water supply device is controlled by the inverter, so that the automatic water supply device is operated with energy saving.

In such an automatic water supply apparatus, a pressure sensor for detecting a discharge pressure of the pump and a flow sensor for detecting a flow rate discharged from the pump are provided in order to automatically operate the pump.

[0004]

If such a pressure sensor or a flow sensor fails, the automatic operation of the pump cannot be performed accurately. Therefore, if the pressure sensor or the flow sensor fails, it is possible to quickly recognize the failure. is necessary.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an automatic water supply apparatus for automatically operating a pump using an inverter, which detects an abnormality of a flow rate sensor or a pressure sensor, and It is an object of the present invention to provide an automatic water supply device having a protection function for preventing malfunction of the water supply device.

[0006]

According to the present invention, there is provided an automatic water supply apparatus comprising: a variable speed operation means for operating a motor for driving a pump at a variable speed; a pressure detection means for detecting a discharge pressure of the pump; Flow rate detection means for detecting the flow rate to be discharged, and the discharge pressure of the pump based on the discharge pressure of the pump detected by the pressure detection means and the flow rate detected by the flow rate detection means so that the target pressure is constant. In an automatic water supply device having a constant target pressure operation means for controlling, an output frequency detection means for detecting an output frequency of the variable speed operation means, and the discharge pressure of the pump is kept at a constant target pressure by the constant target pressure operation means. In such a state, a flow rate equal to or higher than a set flow rate is detected by the flow rate detection means, and the flow rate is detected by the output frequency detection means. If the output frequency of the shift operation means is detected to be the lowest frequency is characterized by comprising an abnormality judging means for judging the abnormality of the flow rate detecting means or the pressure detection means.

That is, while the discharge pressure of the pump is controlled to be constant at the target pressure by the constant target pressure operating means, a flow rate equal to or higher than the set flow rate is detected by the flow rate detecting means, and the output frequency detecting means detects the flow rate. When it is detected that the detected output frequency of the variable speed operation means is the lowest frequency, the flow rate detection means or the pressure detection means is determined to be abnormal.

Therefore, the flow rate detecting means or the pressure detecting means can be provided without adding a special sensor for detecting the failure of the flow rate detecting means or the pressure detecting means only by adding the fault detecting means for detecting such a fault as software. Can be detected.

According to a second aspect of the present invention, there is provided an automatic water supply apparatus, comprising: a variable speed operation means for operating a motor for driving a pump at a variable speed; a pressure detection means for detecting a discharge pressure of the pump; and a flow rate detected by the pump. And a constant pressure target operation for controlling the discharge pressure of the pump to be a constant target pressure based on the discharge pressure of the pump detected by the pressure detection means and the flow rate detected by the flow rate detection means. In the automatic water supply device provided with the means, the output frequency detection means for detecting the output frequency of the variable speed operation means and the constant target pressure operation means are controlled so that the discharge pressure of the pump is constant at the target pressure. In this state, a flow rate equal to or higher than the set flow rate is detected by the flow rate detection means, and the variable speed operation means detected by the output frequency detection means When it is detected that the force frequency is the lowest frequency, abnormality determination means for determining that the flow rate detection means or the pressure detection means is abnormal, and the flow rate detection means or the pressure detection means is abnormal by the abnormality determination means. When it is determined that retry operation is performed, a retry operation is performed in which the operation of the pump is stopped instantaneously and then restarted.

That is, while the discharge pressure of the pump is controlled to be constant at the target pressure by the constant target pressure operation means, a flow rate equal to or higher than the set flow rate is detected by the flow rate detection means, and the output frequency detection means detects the flow rate. When the detected output frequency of the variable speed operation means is detected to be the lowest frequency, the flow rate detection means or the pressure detection means is determined to be abnormal by the abnormality determination means, and the flow rate detection means or the pressure is determined by the abnormality determination means. If the detection means is determined to be abnormal, a retry operation is performed in which the operation of the pump is stopped instantaneously by the retry operation means and then operated again.

For this reason, when a float type flow sensor is used as the flow rate detecting means, dust or the like is caught on the float of the flow rate sensor, and the flow rate erroneously detected by the flow rate detecting means exceeds the set flow rate. Is determined, and the dust is removed by performing a retry operation.

Therefore, only by adding the abnormality detection means for detecting such an abnormality and the retry operation means as software, there is no need to provide a special sensor for detecting a failure of the flow rate detection means or the pressure detection means, and the flow rate detection means is not required. Alternatively, not only can the failure of the pressure detecting means be detected, but also dust and the like that have caused the failure of the sensor can be removed.

According to a third aspect of the present invention, there is provided an automatic water supply apparatus comprising: a variable speed operation means for operating a motor for driving a pump at a variable speed; a pressure detection means for detecting a discharge pressure of the pump; and a flow rate detected by the pump. And a constant pressure target operation for controlling the discharge pressure of the pump to be a constant target pressure based on the discharge pressure of the pump detected by the pressure detection means and the flow rate detected by the flow rate detection means. In the automatic water supply device provided with the means, the output frequency detection means for detecting the output frequency of the variable speed operation means and the constant target pressure operation means are controlled so that the discharge pressure of the pump is constant at the target pressure. In this state, a flow rate equal to or higher than the set flow rate is detected by the flow rate detection means, and the variable speed operation means detected by the output frequency detection means When the force frequency is detected to be the lowest frequency, abnormality determination means for determining that the flow rate detection means or the pressure detection means is abnormal, and the flow rate detection means or the pressure detection means is abnormal by the abnormality determination means. Pump stopping means for stopping the pump when it is determined that

That is, in a state where the discharge pressure of the pump is controlled to be constant at the target pressure by the constant target pressure operating means, a flow rate equal to or higher than the set flow rate is detected by the flow rate detecting means, and the output frequency detecting means is used. When the detected output frequency of the variable speed operation means is detected to be the lowest frequency, the flow rate detection means or the pressure detection means is determined to be abnormal, and the pump is forcibly stopped. .

Accordingly, the flow rate detecting means or the pressure detecting means can be provided only by adding the fault detecting means for detecting such a fault as software without providing a special sensor for detecting the failure of the flow rate detecting means or the pressure detecting means. Can be detected.

Further, in such a case, the seizure of the electric motor driving the pump by forcibly stopping the pump is prevented. In the automatic water supply device according to a fourth aspect, the abnormality detecting means of the automatic water supply device according to any one of the first to third aspects determines that the abnormality is detected after a lapse of a set time after the abnormality is first detected. It is characterized by the following.

As described above, when the abnormality is detected by the abnormality detecting means, it is determined that the state is abnormal when the state continues for the set time for the set time. It is possible to prevent the occurrence of noise in the output signal and the detection of the abnormality by the abnormality detection means.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of the automatic water supply device. In FIG. 1, reference numeral 11 denotes a well. Water 12 is stored in the well 11.

One end of a water supply pipe 13 is provided so as to be immersed in the water 12 of the well 11. The other end of the water supply pipe 13 is connected to a suction port of a pump 15 via a check valve 14.

The rotation of the pump 15 is controlled by a motor 15m. The operating frequency of the motor 15m is controlled by an inverter (variable speed operating means) 16b in the control unit 16.

A water supply pipe 18 in which a flow rate sensor (FS) 17 is interposed is connected to the discharge port of the pump 15. The flow rate sensor 17 detects the flow rate I discharged from the discharge port of the pump 15.

In the water supply pipe 18, a pressure tank 19 is connected downstream of the flow sensor 17. Further, a pressure sensor (PS) 20 is connected to a position further downstream than a position where the pressure tank 19 is connected to the water supply pipe 18. The pressure sensor 20 detects the discharge pressure P of the pump 15.

The control section 16 is mainly composed of a CPU 16a and an inverter 16b. The inverter 16b outputs to the motor 15m an operation signal whose frequency changes from fmin to fmax.

Also, the motor 15m is connected to the inverter 16b.
The output frequency of the operating current output to the controller is detected by the output frequency detector 16c as output frequency detecting means.
Further, the control unit 16 determines that the flow rate I detected by the flow rate sensor 17 is equal to or higher than the set flow rate Io, and outputs the motor 15 m from the inverter 16 b detected by the output frequency detection unit 16 c.
In the case where the output frequency of the operating current to be output is the lowest frequency, an alarm 16d for issuing an alarm is connected.

Reference numeral 16e is a timer for measuring time. Next, the first embodiment of the present invention configured as described above
The operation of the embodiment will be described. First, a target pressure constant operation is performed (target pressure constant operation means) (step S1). The target pressure constant operation refers to the discharge pressure P detected by the pressure sensor 20 installed in the water supply pipe 18.
Means controlling the operating frequency of the inverter 16b so that the target pressure becomes the target pressure Pt.

As described above, while the constant target pressure operation is being performed, the flow rate I discharged from the pump 15 is detected by the flow rate sensor 17 (step S2). Then, it is determined whether the flow rate I detected by the flow rate sensor 17 is equal to or greater than the set flow rate Io (step S3).

If the determination in step S3 is "YES", the output frequency f of the operating current output from the inverter 16b to the motor 15m is detected by the output frequency detector 16c (step S4).

Then, it is determined whether the output frequency f detected by the output frequency detector 16c is the lowest frequency fmin (step S5). If "YES" is determined in step S5, it is determined that the flow sensor 17 or the pressure sensor 20 is abnormal (step S6).

Then, a retry operation is performed (retry operation means) (step S7). This retry operation
This means that the operation of the pump 15 is stopped immediately and the operation is started again.

More specifically, the control is performed by controlling the operating current output from the inverter 16b to the motor 15m. In step S3 or S5,
If “NO” is determined, the above-described step S2
Return to the processing of.

As described above, it is determined that the flow rate I detected by the flow rate sensor 17 is equal to or higher than the set flow rate Io, and the output frequency f of the operating current output from the inverter 16b to the motor 15m is determined by the output frequency detection section 16c. If it is determined that the frequency is the minimum frequency fmin, the flow rate sensor 17
Alternatively, it is determined that the pressure sensor 20 is out of order, the pump 15 is instantaneously stopped, and the operation is restarted, so that, for example, the dust on the float of the flow rate sensor 17 can be removed.

In this manner, malfunction of the flow sensor 17 can be eliminated. Next, the operation of the second embodiment of the present invention will be described with reference to the flowchart of FIG. First, the target pressure constant operation is performed (target pressure constant operation means) (step S11). The constant target pressure operation refers to a pressure sensor 20 installed in the water supply pipe 18.
Means that the operating frequency of the inverter 16b is controlled so that the discharge pressure P detected in the step (b) becomes the target pressure Pt.

As described above, while the constant target pressure operation is being performed, the flow rate sensor 17 detects the flow rate I discharged from the pump 15 (step S12). And
The flow rate I detected by the flow rate sensor 17 is the set flow rate Io.
It is determined whether or not it has been performed (step S13).

When the determination in step S13 is "YES", the output frequency f of the operating current output from the inverter 16b to the motor 15m is detected by the output frequency detector 16c (step S14).

Then, it is determined whether or not the output frequency f detected by the output frequency detector 16c is the lowest frequency fmin (step S15). If the determination in step S15 is "YES", the timer 16e starts counting time. This timer 16e
It is determined whether or not the set time To has elapsed (step S16).

That is, "N" is determined in step S16.
While it is determined to be "O", the processing after step S12 is repeatedly performed. Then, first, step S15
When the set time elapses after the determination in step S16 is "YES", the determination in step S16 is "YES", and the flow sensor 1
7 or that the pressure sensor 20 has failed (step S17).

Then, the pump 15 is forcibly stopped (pump stopping means), and the alarm 16d is operated to issue a warning from the alarm 16d (step S1).
8).

If it is determined "NO" in step S13 or S15, the process returns to step S12. As described above, the flow sensor 17
Is determined to be equal to or greater than the set flow rate Io, and the output frequency
Frequency f of operating current output from motor to motor 15m
Is determined to be the minimum frequency fmin and the set time T
After o has elapsed, it is determined that the flow sensor 17 or the pressure sensor 20 has failed, the pump 15 is forcibly stopped, and an alarm is output from the alarm device 16d.

As described above, when the abnormality is detected by the abnormality detecting means, if the state continues for the set time for the set time, it is determined that the state is abnormal. It is possible to prevent the occurrence of noise in the output signal and the detection of the abnormality by the abnormality detection means.

Next, the operation of the third embodiment of the present invention will be described with reference to the flowchart of FIG. First, the target pressure constant operation is performed (target pressure constant operation means) (step S31). This constant target pressure operation is
This means controlling the operation frequency of the inverter 16b so that the discharge pressure P detected by the pressure sensor 20 installed in the water supply pipe 18 becomes the target pressure Pt.

As described above, while the constant target pressure operation is being performed, the flow rate I discharged from the pump 15 is detected by the flow rate sensor 17 (step S32). And
The flow rate I detected by the flow rate sensor 17 is the set flow rate Io.
It is determined whether there is the above (step S33).

If "YES" is determined in step S3, the output frequency f of the operating current output from the inverter 16b to the motor 15m is detected by the output frequency detector 16c (step S34).

Then, it is determined whether or not the output frequency f detected by the output frequency detector 16c is the lowest frequency fmin (step S35). If “YES” is determined in step S35, it is determined that the flow rate sensor 17 or the pressure sensor 20 is abnormal (step S36).

Then, the pump 15 is forcibly stopped (pump stopping means) (step S37). If “NO” is determined in step S3 or S35, the process returns to step S22 described above.

As described above, it is determined that the flow rate I detected by the flow rate sensor 17 is equal to or greater than the set flow rate Io, and the output frequency f of the operating current output from the inverter 16b to the motor 15m is determined by the output frequency detection section 16c. If it is determined that the frequency is the minimum frequency fmin, the flow rate sensor 17
Or, it is determined that the pressure sensor 20 has failed, and the pump 15 is forcibly stopped. In this way, the seizure of the electric motor that drives the pump by forcibly stopping the pump is prevented.

[0046]

According to the first aspect of the present invention, while the discharge pressure of the pump is controlled by the constant target pressure operation means to be constant, the flow rate detection means detects a flow rate equal to or higher than the set flow rate. If the output frequency of the variable speed operation means is detected as being the lowest frequency and is detected by the output frequency detection means, the flow rate detection means or the pressure detection means is determined to be abnormal. .

Therefore, only by adding the abnormality detecting means for detecting such an abnormality as software, without providing a special sensor for detecting a failure of the flow detecting means or the pressure detecting means, the flow detecting means or the pressure detecting means can be provided. Can be detected.

According to the second aspect of the present invention, while the discharge pressure of the pump is controlled to be constant at the target pressure by the constant target pressure operation means, a flow rate equal to or higher than the set flow rate is detected by the flow rate detection means. When the output frequency of the variable speed operation means detected by the output frequency detection means is the lowest frequency, the flow rate detection means or the pressure detection means is determined to be abnormal by the abnormality determination means, When the determination means determines that the flow rate detection means or the pressure detection means is abnormal, the retry operation means performs a retry operation in which the operation of the pump is instantaneously stopped and then restarted.

For this reason, when a float type flow sensor is used as the flow rate detecting means, dust or the like is caught on the float of the flow rate sensor, and the flow rate erroneously detected by the flow rate detecting means exceeds the set flow rate. Is determined, and the dust is removed by performing a retry operation.

Therefore, only by adding the abnormality detecting means for detecting such an abnormality and the retry operation means as software, without providing a special sensor for detecting a failure of the flow detecting means or the pressure detecting means, the flow detecting means can be provided. Alternatively, not only can the failure of the pressure detecting means be detected, but also dust and the like that have caused the failure of the sensor can be removed.

According to the third aspect of the present invention, while the discharge pressure of the pump is controlled by the constant target pressure operating means to be constant, the flow rate detection means detects a flow rate equal to or higher than the set flow rate. When the output frequency of the variable speed operation means detected by the output frequency detection means is the lowest frequency, the flow rate detection means or the pressure detection means is determined to be abnormal, and the pump is forcibly operated. It is trying to stop temporarily.

Therefore, only by adding the abnormality detecting means for detecting such an abnormality as software, without providing a special sensor for detecting a failure of the flow rate detecting means or the pressure detecting means, the flow rate detecting means or the pressure detecting means is not required. Can be detected.

Further, in such a case, the seizure of the electric motor for driving the pump by forcibly stopping the pump is prevented. According to the fourth aspect of the present invention, when an abnormality is detected by the abnormality detecting means, it is determined that the state is abnormal when the state continues for the set time for the set time. It is possible to prevent the occurrence of noise in the signal output from the detection means and the detection of the abnormality by the abnormality detection means.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire configuration of an automatic water supply device according to the present invention.

FIG. 2 is a flowchart showing the operation of the first embodiment of the present invention.
Chart.

FIG. 3 is a flowchart showing the operation of the second embodiment of the present invention.
Chart.

FIG. 4 is a flow chart showing the operation of the third embodiment of the present invention.
Chart.

[Explanation of symbols]

 11 well, 12 water, 13 water supply pipe, 14 check valve, 15 pump, 15 m motor, 16 control unit, 17 flow rate sensor, 18 water supply pipe, 19 pressure tank, 20 pressure sensor .

Claims (4)

[Claims] A variable speed operation means for operating a motor for driving a pump at a variable speed; a pressure detection means for detecting a discharge pressure of the pump; a flow detection means for detecting a flow rate discharged from the pump; An automatic water supply device having a constant target pressure operation means for controlling the discharge pressure of the pump based on the discharge pressure of the pump detected by the detection means and the flow rate detected by the flow rate detection means so that the target pressure is constant. An output frequency detecting means for detecting an output frequency of the variable speed operating means, and a state in which the discharge pressure of the pump is controlled by the constant target pressure operating means to be a constant target pressure. A flow rate greater than the set flow rate is detected,
And, when the output frequency of the variable speed operating means detected by the output frequency detecting means is detected to be the lowest frequency, the flow rate detecting means or the abnormality determining means for determining that the pressure detecting means is abnormal. An automatic water supply device, comprising: 2. A variable speed operation means for operating a motor for driving a pump at a variable speed, a pressure detection means for detecting a discharge pressure of the pump, a flow rate detection means for detecting a flow rate discharged from the pump, and the pressure An automatic water supply device having a constant target pressure operation means for controlling the discharge pressure of the pump based on the discharge pressure of the pump detected by the detection means and the flow rate detected by the flow rate detection means so that the target pressure is constant. An output frequency detecting means for detecting an output frequency of the variable speed operating means, and a state in which the discharge pressure of the pump is controlled by the constant target pressure operating means to be a constant target pressure. A flow rate greater than the set flow rate is detected,
And when the output frequency of the variable speed operation means detected by the output frequency detection means is detected as the lowest frequency, abnormality determination means for determining that the flow rate detection means or the pressure detection means is abnormal, When the abnormality determination means determines that the flow rate detection means or the pressure detection means is abnormal, retry operation means for performing a retry operation of immediately stopping the operation of the pump and then operating the pump again is provided. Features automatic water supply. 3. A variable speed operation means for operating a motor for driving a pump at a variable speed, a pressure detection means for detecting a discharge pressure of the pump, a flow rate detection means for detecting a flow rate discharged from the pump, and the pressure An automatic water supply device having a constant target pressure operation means for controlling the discharge pressure of the pump based on the discharge pressure of the pump detected by the detection means and the flow rate detected by the flow rate detection means so that the target pressure is constant. An output frequency detecting means for detecting an output frequency of the variable speed operating means, and a state in which the discharge pressure of the pump is controlled by the constant target pressure operating means to be a constant target pressure. A flow rate greater than the set flow rate is detected,
And when the output frequency of the variable speed operation means detected by the output frequency detection means is detected as the lowest frequency, abnormality determination means for determining that the flow rate detection means or the pressure detection means is abnormal, An automatic water supply device comprising: a pump stopping means for stopping the pump when the flow rate detecting means or the pressure detecting means is determined to be abnormal by the abnormality determining means. 4. The automatic water supply apparatus according to claim 1, wherein the abnormality detecting means determines that the abnormality is abnormal after a lapse of a set time after the abnormality is first detected. .