JP6644618B2 - Water level control device - Google Patents

Description

  The present invention relates to a water level control device.

  2. Description of the Related Art Conventionally, a submersible pump is installed in a sewage tank that temporarily stores sewage discharged from each household. Then, when the amount of sewage increases, the sewage is pumped up by a submersible pump and discharged to a sewer pipe or the like on the downstream side to promote the sewage circulation process (for example, see Patent Document 1). .

  The water level control device of Patent Literature 1 includes a pressure sensor that detects the air pressure supplied to the sewage through an air pump. If the sewage flows into the sewage tank and rises to a predetermined water level, the air pressure corresponding to the water level is increased. Acts, the controller determines that the water level has risen to the predetermined water level, and drives the submersible pump to discharge sewage. Then, when the water level drops to a predetermined pump stop water level due to discharge of sewage, the pressure sensor detects an air pressure corresponding to the predetermined pump stop water level, and stops driving the submersible pump.

JP 2001-193140 A

  However, for example, when a conventional water level control device is applied to a highly airtight sewage tank, the pressure sensor generates a negative pressure (a pressure lower than the atmospheric pressure) that should not be detected in normal operation. There is a possibility that error processing such as emergency stop of the pump or notification of an abnormality may occur upon detection and determination of the abnormality.

  Specifically, in a highly airtight sewage tank, while the sewage is discharged, the inside of the sewage tank may have a negative pressure because air corresponding to the volume of the discharged sewage does not flow in from the outside. At this time, if the detection unit of the pressure sensor is exposed to the air or is near the water surface, the pressure sensor may detect a negative pressure. In this type of device, when the pressure sensor detects a negative pressure, it is determined that a detection error has occurred, an error message is transmitted, and error processing such as stopping the operation of the pump is performed. Frequent processing puts a burden on the workers for corresponding tasks.

  The present invention has been made in view of such a point, and an object of the present invention is to suppress frequent occurrence of a response operation associated with error processing when the inside of a water storage tank temporarily becomes a negative pressure. .

A first invention is provided in a water storage tank in which water is stored, and a pump for discharging water from the water storage tank,
A water level detection unit that has a pressure sensor that detects a pressure in the water storage tank, and detects a water level of the water storage tank based on a detection result of the pressure sensor,
While the pump is stopped, the pump is started when the water level detected by the water level detection unit is equal to or higher than a predetermined startup water level, and the water level detected by the water level detection unit during operation of the pump is A control unit that stops the pump when the water level falls below a predetermined stop water level lower than the start water level,
When a negative pressure is detected by the pressure sensor, comprising an error determination unit that determines that it is a detection error,
The control unit controls so as not to perform at least a part of error processing due to a detection error of the pressure sensor until a predetermined set time elapses after starting the pump. It is.

  In the first aspect, when a negative pressure is detected by the pressure sensor, the error determination unit determines that a detection error has occurred and performs error processing. Until the time elapses, at least a part of the error processing is not performed.

  Thereby, even when the pressure inside the highly airtight water storage tank temporarily becomes negative, unnecessary error processing is suppressed from occurring frequently, and the water level control can be continuously performed.

  More specifically, in a highly airtight water tank, the inside of the water tank temporarily becomes negative pressure due to insufficient air flow from the outside to the volume of drained wastewater, and The detecting unit of the pressure sensor at a shallow position may detect a negative pressure. In other words, even if the pressure sensor detects a negative pressure, a malfunction such as disconnection of the pressure sensor or a negative pressure over a long period of time does not necessarily affect the pump operation control. Sending a message or shutting down the pump is not preferred.

  Therefore, in the present invention, unnecessary processing is performed by performing error processing due to a detection error of the pressure sensor in a state where a predetermined elapsed time has elapsed since the start of the pump and the inside of the water storage tank is likely to have returned to the atmospheric pressure. Frequent error handling is suppressed.

  In addition, it is conceivable that while the record of the detection error is stored in the memory, the pump is not stopped or the notification operation is not performed.

In a second aspect, in the first aspect,
The control unit controls the pump not to be stopped by the error processing until the set time elapses.

  According to the second aspect, even if the pressure in the water storage tank becomes negative during the set time, the operation of the pump can be continued without forcibly stopping the pump by error processing due to a detection error.

A third invention is a method according to the first or second invention,
When the error determination unit is determined to be a detection error, a notification unit that performs a predetermined notification operation as an error process,
The notification unit is configured not to perform the notification operation until the set time elapses.

  In the third aspect of the invention, the detection error is not determined until the set time elapses, or the notification operation is not performed even if the detection error is determined. Thereby, it is possible to prevent the notification operation from frequently occurring based on an unnecessary detection error that does not affect the water level control.

A fourth invention is provided in a water tank for storing water, and a pump for discharging water from the water tank,
A water level detection unit having a pressure sensor for detecting a pressure in the water storage tank, and detecting a water level of the water storage tank based on a detection result of the pressure sensor,
While the pump is stopped, the pump is started when the water level detected by the water level detection unit is equal to or higher than a predetermined startup water level, and the water level detected by the water level detection unit during operation of the pump is A control unit that stops the pump when the water level falls below a predetermined stop water level lower than the start water level,
When a negative pressure is detected by the pressure sensor, an error determination unit that determines that it is a detection error,
The control unit controls the pump to continue operating until the predetermined extension time elapses after the water level in the water storage tank falls below the stop water level, while performing error processing due to a detection error. Is controlled so as not to perform at least a part of.

  In the fourth invention, after the water level in the water storage tank becomes equal to or lower than the stop water level, the operation of the pump is continued until the predetermined extension time elapses, and the water in the water storage tank can be reliably discharged. Like that. During the extended time, at least a part of the error processing is not performed even if the detecting unit of the pressure sensor detects the negative pressure.

  Here, in order to detect the water level with the pressure sensor, it is assumed that the air pressure changes depending on the water level, that is, the pressure sensor is underwater. That is, when the water level is at the stop water level, the pressure sensor is still underwater. If the inside of the water tank becomes negative pressure, the pressure sensor in the water detects a pressure lower than the pressure corresponding to the actual water level, so after the stop sensor detects the stop water level in the air or relatively shallow water. The possibility of detecting a negative pressure during the extended time is high.

  Therefore, in the present invention, during the extended time in which the pressure sensor is likely to detect a negative pressure, by not performing at least a part of the error processing based on the detection error, it is unnecessary to have no influence on the water level control. Frequent error handling is suppressed.

  In addition, if the apparatus originally has a timer function for counting the extension time, it is not necessary to separately provide a timer function for measuring a set time for not performing determination of a detection error, and the apparatus can be shared.

  ADVANTAGE OF THE INVENTION According to this invention, even if the inside of a highly airtight water storage tank becomes a negative pressure temporarily, unnecessary error processing can be suppressed from occurring frequently, and water level control can be performed continuously.

It is a side view showing a schematic structure of a water level control device concerning this embodiment. FIG. 4 is a timing chart illustrating a timing at which error processing is performed. FIG. 9 is a timing chart illustrating a timing of performing an error process in the water level control device according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely an example in nature, and is not intended to limit the present invention, its application, or its use.

<< Embodiment 1 >>
As shown in FIG. 1, the water level control device 10 controls a water level of a water storage tank 15 such as a manhole in which water is stored. The water storage tank 15 is provided with an inflow pipe 16 and an outflow pipe 17, so that water can appropriately flow into the water storage tank 15 through the inflow pipe 16.

  A submersible pump 20 for pumping and discharging water is provided inside the water storage tank 15. The suction bell mouth 21 of the submersible pump 20 is disposed in a recess 18 provided at the bottom of the water storage tank 15. The discharge pipe 22 of the submersible pump 20 is connected to the outflow pipe 17 of the water storage tank 15 so as to discharge the water pumped by the submersible pump 20 to the outside of the water storage tank 15. The operation and stop of the submersible pump 20 are controlled by a controller 35 as a control unit that executes water level control described later.

  The water level of the water in the water storage tank 15 is detected by a bubble type liquid level meter 30 as a water level detection unit. The bubble-type liquid level gauge 30 includes an air pump 31, an air discharge unit 32 arranged to be immersed in water, an air tube 33 connecting the air pump 31 and the air discharge unit 32, and an air tube 33. A pressure sensor 34 for detecting air pressure.

  When supplying air into the water in the water storage tank 15 to generate bubbles, the bubble-type liquid level gauge 30 detects fluctuations in the air pressure in the air tube 33 with the pressure sensor 34, and based on the detection result, detects the water level. Is configured to be detected. The pressure sensor 34 is connected to the controller 35, and the value detected by the pressure sensor 34 is transmitted to the controller 35.

  The controller 35 controls the operation of the submersible pump 20 based on the water level detected by the bubble type liquid level gauge 30. Specifically, the controller 35 activates the submersible pump 20 when the water level detected by the bubble type liquid level gauge 30 becomes higher than or equal to a predetermined activation water level H1 while the submersible pump 20 is stopped. As a result, the water in the water storage tank 15 is discharged to the outside, and the water level in the water storage tank 15 decreases.

  On the other hand, when the water level detected by the bubble type liquid level gauge 30 during the operation of the submersible pump 20 falls below the predetermined stop water level L, the submersible pump 20 is stopped. Thereby, the pumping of water is completed, and the water flowing in from the outside is stored in the water storage tank 15.

  In the present embodiment, the submersible pump 20 is not stopped immediately when the water level becomes equal to or lower than the stop water level L. The operation of the pump 20 is continued. Thereby, the water stored in the concave portion 18 of the water storage tank 15 can be reliably discharged.

  The controller 35 has an error determination unit 36 that determines that a detection error has occurred when a negative pressure is detected by the pressure sensor 34. Further, the controller 35 is connected to a notification unit 37 that performs a predetermined notification operation.

  The notification unit 37 includes, for example, a monitor, and displays an error message indicating a detection error of the pressure sensor 34. The notification unit 37 is not limited to a monitor, and may be a notification buzzer, a notification lamp, or the like. That is, the notification operation of the notification unit 37 notifies the worker of a detection error by, for example, displaying an error message on a monitor at hand or a monitoring monitor at a remote location, sounding a notification buzzer, and blinking a notification lamp. Anything should do.

  By the way, in the highly airtight water storage tank 15, while the sewage is discharged, the inside of the water storage tank 15 may temporarily become a negative pressure because the air corresponding to the volume of the discharged sewage does not flow in from the outside. is there. At this time, the pressure sensor 34 in the water storage tank 15 may detect a negative pressure. In this case, the error determination unit 36 determines that a detection error has occurred, and the controller 35 performs control such as displaying an error message on the notification unit 37 and forcibly stopping the submersible pump 20. That is, a detection error frequently occurs even though no trouble such as disconnection has occurred in the pressure sensor 34.

  Therefore, in the present embodiment, the occurrence of unnecessary detection errors that do not affect the water level control is suppressed, and the water level control can be continuously performed. Hereinafter, description will be made with reference to the timing chart of FIG.

  First, at time T1, the water level in the water storage tank 15 becomes the starting water level H1, and the controller 35 starts the submersible pump 20 to start discharging water. At this time, positive pressure is detected by the pressure sensor 34. Then, the controller 35 controls so as not to perform at least a part of the error processing due to the detection error until the predetermined set time elapses.

  Note that the set time can be appropriately set by an operator inputting from the controller 35 according to the structure of the water storage tank 15, the performance of the submersible pump 20, and the like. For example, it can be set in an arbitrary range, such as 1 to 99 seconds in one second steps.

  At time T2, the water level in the water storage tank 15 becomes the stop water level L, and the controller 35 continues the operation of the submersible pump 20 until a predetermined extension time elapses.

  At time T3, during the extension time, a negative pressure in the water storage tank 15 is detected by the pressure sensor 34 due to a decrease in water pressure due to a decrease in water level and a decrease in atmospheric pressure of the air portion. Here, since the negative pressure is detected by the pressure sensor 34, the submersible pump 20 is forcibly stopped as an error process although the extension time is in the middle. However, at the time T3, since the predetermined set time has not elapsed, the controller 35 controls the notifying unit 37 so that the notifying operation as the error processing is not performed.

  At time T4, a predetermined extension time has elapsed, but since the submersible pump 20 has already stopped, no particular processing is performed.

  Further, air gradually flows into the water storage tank 15, and at time T5, a predetermined set time has elapsed, so that if the pressure sensor 34 detects a negative pressure, error processing based on a negative pressure error is performed. However, at time T5, the positive pressure is detected by the pressure sensor 34, and no detection error occurs.

  At time T6, the pressure in the water storage tank 15 is positive.

  As described above, in the water level control device 10 according to the present embodiment, when a negative pressure is detected by the pressure sensor 34, the error determination unit 36 determines that a detection error has occurred. The notification operation of the error processing is not performed until a predetermined elapsed time elapses after the activation of.

  Thereby, even when the inside of the highly airtight water storage tank 15 temporarily becomes negative pressure, it is possible to suppress frequent occurrence of unnecessary error notification and to continue the water level control.

<< Embodiment 2 >>
FIG. 3 is a timing chart illustrating a timing at which an error determination is performed in the water level control device according to the second embodiment. Hereinafter, the same portions as those in the first embodiment are denoted by the same reference numerals, and only the differences will be described.

  As shown in FIG. 3, first, at time T1, the water level in the water storage tank 15 becomes the starting water level H1, and the controller 35 activates the submersible pump 20 to start discharging water. At this time, the air discharge unit 32 is immersed in water, and the pressure sensor 34 detects a positive pressure. Then, the controller 35 performs control so that error processing due to a detection error is not performed until a predetermined set time elapses.

  At time T2, the water level in the water storage tank 15 becomes the stop water level L, and the controller 35 continues the operation of the submersible pump 20 until a predetermined extension time elapses. At this time, the pressure in the water storage tank 15 is a negative pressure, but the pressure sensor 34 detects a positive pressure.

  At time T3, during the extended time, the pressure in the water storage tank 15 further decreases due to the small inflow of air with respect to the discharge amount of the sewage, and the detection pressure decreases due to the decrease in the water level, and the negative pressure is detected by the pressure sensor 34. You. However, at the time T3, since the predetermined set time has not elapsed, the error processing based on the negative pressure error is not performed, and the controller 35 continues the operation of the submersible pump 20 and notifies the notification unit 37. Control is performed so that the notification operation is not performed.

  At time T4, since the predetermined extension time has elapsed, the controller 35 stops the operation of the submersible pump 20.

  At time T5, the water level in the water storage tank 15 increases, and air gradually flows into the water storage tank 15, and the pressure sensor 34 detects a positive pressure.

  At time T6, since a predetermined set time has elapsed, the error determination unit 36 determines a detection error. At time T6, the air discharge unit 32 is immersed in water, and the pressure sensor 34 detects a positive pressure, and no detection error occurs.

  At time T7, the air pressure in the water storage tank 15 is also positive.

  In this way, even if the pressure inside the water storage tank 15 becomes negative during the set time and the negative pressure is detected by the pressure sensor 34, no error processing is performed as a detection error. Further, the operation can be continued without forcibly stopping the submersible pump 20.

<< Other embodiments >>
The above embodiment may have the following configuration.

  In the present embodiment, the air pressure in the water storage tank 15 is maintained at a negative pressure during the extended time. However, for example, if the water storage tank 15 is not so airtight, the water pressure in the water storage tank 15 during the extended time is reduced. May recover from negative pressure to positive pressure.

  For such a water storage tank 15, the controller 35 continues the operation of the submersible pump 20 until the predetermined extension time elapses after the water level in the water storage tank 15 becomes equal to or lower than the stop water level L. On the other hand, the error determination unit 36 may be controlled so that at least a part of the error processing due to the detection error of the pressure sensor 34 is not performed.

  That is, at least a part of the error processing due to the detection error is not performed only during the extended time when the air discharge unit 32 is exposed to the air or near the water surface and the pressure sensor 34 is likely to detect the negative pressure. By doing so, frequent occurrence of unnecessary error processing that does not affect the water level control can be suppressed. On the other hand, when there is a high possibility of a detection error due to other disconnection or the like, error processing such as pump stop or error notification can be performed promptly.

  As described above, the present invention has a highly practical effect that it is possible to suppress frequent occurrence of error processing due to a detection error of the pressure sensor when the inside of the water tank temporarily becomes negative pressure. As a result, it is extremely useful and has high industrial applicability.

10 water level control device 15 water tank 20 submersible pump (pump)
30 Bubble level meter (water level detector)
34 Pressure sensor 35 Controller (control unit)
36 Error determination unit 37 Notification unit

Claims (4)

A pump installed in a water storage tank for storing water and discharging water from the water storage tank;
A water level detection unit having a pressure sensor for detecting a pressure in the water storage tank, and detecting a water level of the water storage tank based on a detection result of the pressure sensor,
While the pump is stopped, the pump is started when the water level detected by the water level detection unit is equal to or higher than a predetermined startup water level, and the water level detected by the water level detection unit during operation of the pump is A control unit that stops the pump when the water level falls below a predetermined stop water level lower than the start water level,
When a negative pressure is detected by the pressure sensor, an error determination unit that determines that it is a detection error,
The control unit performs control so as not to perform at least a part of the error processing due to the detection error of the pressure sensor until a predetermined set time elapses after starting the pump. Control device. In claim 1,
The water level control device, wherein the control unit controls so as not to stop the pump due to the error processing until the set time elapses. In claim 1 or 2,
When the error determination unit is determined to be a detection error, a notification unit that performs a predetermined notification operation as error processing,
The water level control device, wherein the notification unit is configured not to perform the notification operation until the set time elapses. A pump installed in a water storage tank for storing water and discharging water from the water storage tank;
A water level detection unit that has a pressure sensor that detects a pressure in the water storage tank, and detects a water level of the water storage tank based on a detection result of the pressure sensor,
While the pump is stopped, the pump is started when the water level detected by the water level detection unit is equal to or higher than a predetermined startup water level, and the water level detected by the water level detection unit during operation of the pump is A control unit that stops the pump when the water level falls below a predetermined stop water level lower than the start water level,
When a negative pressure is detected by the pressure sensor, an error determination unit that determines that it is a detection error,
The control unit controls the pump to continue operating until the predetermined extension time elapses after the water level in the water storage tank falls below the stop water level, while performing error processing due to a detection error. A water level control device that performs control so as not to perform at least a part of the water level control.

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