JP2021025433A - Water supply system and control method for water supply system - Google Patents

Abstract

To provide a water supply system capable of shifting to automatic operation using a normal pressure sensor by promptly and surely detecting abnormality of a pressure sensor, and a control method for the water supply system.SOLUTION: A water supply system detects/stores every time a small water quantity time operation frequency f0 in the case where each of pump devices is stopped in a small water quantity state. In the case where the quantity of supplied water is decreased and an operating pump is to be stopped in the small water quantity state, a pressure deviation that is a deviation of signal levels between a first pressure sensor and a second pressure sensor is calculated. In the case where the pressure deviation is equal to or greater than a predetermined pressure deviation ▵h decided beforehand, a frequency deviation (f) between the small water quantity time operation frequency f0 and an initial small water quantity time operation frequency f0' of the pump is further calculated. In the case where the frequency deviation (f) is equal to or greater than a predetermined frequency deviation ▵f decided beforehand, sensor switch processing is performed for controlling operation of the pump device using a second discharge pressure which is detected by the second pressure sensor.SELECTED DRAWING: Figure 8

Description

The present invention relates to a water supply device and a method for controlling the water supply device.

In a water supply device that sends water to a house or the like, an inverter is known to control the rotation speed of a motor that drives a pump device. For example, in a water supply device, a flow path on the suction side is connected to a water tank, and a flow path on the discharge side is connected to a plurality of water supply devices at a water supply destination. In the water supply device, for example, the discharge pressure is detected by a pressure sensor arranged in the discharge pipe, and based on the detected discharge pressure and the target pressure, the motor is operated by a control method such as a constant discharge pressure control method or an estimated constant end pressure control method. The output frequency to is controlled.

JP-A-2017-106363

In such a water supply device, for example, when the signal level of the pressure sensor deviates from a predetermined range, it is determined that the pressure sensor has failed, and control is performed to shift to a backup operation in which the pump is started at regular intervals. There is. Such a water supply device has a failure condition when the signal of the pressure sensor is out of the rated output range, and there is a problem that the failure detection is delayed until the pressure sensor is seriously damaged. Therefore, a plurality of pressure sensors are used. Even in the case of the water supply device, if the pressure sensors of the same specifications are used under the same conditions, the probability of occurrence of each failure is the same. Therefore, since it is unknown which pressure sensor is out of order, there is a problem that erroneous detection may occur if the failure of the pressure sensor in use is determined based on the spare pressure sensor. Therefore, there is a need for a water supply device and a control method for the water supply device that can quickly and surely detect a failure of the main pressure sensor in use and shift to a backup operation using the sub pressure sensor.

The water supply device according to the embodiment includes a pump device, a piping unit having a discharge side pipe connected to the discharge side of the pump device, and a first pressure sensor and a second pressure sensor for detecting the pressure of the discharge side pipe. With the pressure detection unit having and the constant discharge pressure control with the predetermined set pressure P1 as the target pressure, or with the estimated terminal pressure constant control with the value between the predetermined set pressure P1 and the estimated terminal pressure P2 as the target pressure. The pump device is operated and controlled so that the first discharge pressure detected by the first pressure sensor becomes the target pressure, and the operation frequency f0 at the time of a small amount of water when each pump device stops the small amount of water is detected every time. -In addition to being memorized, when the amount of water supplied decreases and the operation pump is stopped with a small amount of water while operating with the first pressure sensor, the deviation of the signal level from the first pressure sensor and the second pressure sensor. If the pressure deviation is greater than or equal to a predetermined pressure deviation Δh, the operating frequency f0 at the time of small water volume and the operating frequency f0'at the initial small water volume of the corresponding pump are further calculated. The frequency deviation f is calculated, and when the frequency deviation f is equal to or greater than a predetermined frequency deviation Δf, an abnormality of the first pressure sensor is sent to the outside and detected by the second pressure sensor. It includes a control unit that performs a sensor switching process that controls the operation of the pump device using the second discharge pressure.

According to the present invention, it is possible to provide a water supply device and a control method of a water supply device that can quickly and surely determine a failure and shift to automatic operation by a normal pressure sensor.

The side view which shows the structure of the water supply device which concerns on 1st Embodiment. The front view which shows the structure of the water supply device. Explanatory drawing which shows the structure of the water supply device. The front view which shows a part of the structure of the water supply device. Explanatory drawing which shows the correspondence between each reference value of the water supply device, a head and a voltage. An explanatory diagram showing the correspondence between each reference value of the water supply device and the operating frequency. The flowchart which shows the control method of the water supply device. The flowchart which shows the control method of the water supply device. The flowchart which shows the control method of the water supply device. Explanatory drawing which shows a part of the structure of the water supply device which concerns on other embodiment. Explanatory drawing which shows a part of the structure of the water supply device which concerns on other embodiment.

[First Embodiment]
Hereinafter, the water supply device according to the embodiment of the present invention will be described with reference to FIGS. 1 to 7. 1 to 4 show the configuration of a water supply device according to an embodiment of the present invention. FIG. 1 is a side view of the water supply device, FIG. 2 is a front view, and FIG. 3 is an explanatory view of the discharge side piping unit as viewed from the front. FIG. 4 is an explanatory diagram showing a part of the water supply device, FIG. 5 is an explanatory diagram showing the correspondence between each reference value and the head and voltage, and FIG. 6 is an explanation showing the correspondence between each reference value and the operating frequency. 7 to 9 are flowcharts showing a control method of the water supply device. For the sake of explanation, the configurations are omitted in each figure as appropriate.

As shown in FIGS. 1 to 4, the water supply device 10 includes a base 11, a plurality of pump devices 12, a piping unit 13, and a control panel 14 including a plurality of inverters and control boards, for example, a building or the like. Water is sent to multiple water supply destinations. The suction side pipe on the primary side of the water supply device 10 is connected to the water receiving tank.

The base 11 supports a vibration-proof pedestal 11b on which a plurality of pump devices 12 and a piping unit 13 are mounted, and a control panel pedestal 11c on which a control panel 14 is mounted at a predetermined installation location.

Each pump device 12 includes a motor 21 and a one-stage or multiple-stage pump unit 22 having an impeller connected to the motor 21, and boosts the fluid to pump it to the secondary side. In the present embodiment, three pump devices 12 are installed vertically on the anti-vibration stand 11b side by side in the first direction.

The motor 21 is, for example, a brushless motor. Each of the motors 21 is connected to the control panel 14 by a cable. The motor 21 is connected to the control board via an inverter, and the rotation speed is controlled by the control of the control unit 41 mounted on the control board.

The pump unit 22 is, for example, a turbine pump including one or more impellers and a casing having a pump suction port and a pump discharge port.

The pump device 12 sucks the liquid from the pump suction port connected to the water pipe and discharges it from the pump discharge port connected to the water supply destination by rotating the impeller in the casing 24 with the rotation of the motor 21. The plurality of pump devices 12 have the same pumping performance. For example, in the present embodiment, as the three pump devices 12, a multi-stage turbine pump of the same model having the same pumping performance was used.

The piping unit 13 includes a plurality of suction-side pipes 31 connected to the primary side of each pump device 12, and a discharge-side pipe 32 connected to the secondary side of each pump device 12.

One end of the suction side pipe 31 is connected to the water pipe, and the other end is connected to the pump suction port of each pump device 12.

The discharge side pipe 32 includes a plurality of individual discharge pipes 33 and a discharge connecting pipe 34 that connects the plurality of individual discharge pipes 33 to each other. The secondary side of the discharge side pipe 32 is branched into a plurality of parts and connected to a plurality of water supply destination water supply devices.

One end of each of the plurality of individual discharge pipes 33 is connected to the pump discharge ports of the plurality of pump devices 12, and the other end side is connected to a common discharge connecting pipe 34. The individual discharge pipe 33 is provided with a connecting curved pipe 35a, a flow rate sensor 35b, a check valve 36, and a ball valve 37 (open / close valve), respectively. The plurality of individual discharge pipes 33 are connected to the discharge connecting pipe 34 and communicate with the individual discharge pipes 33 of the other pump device 12.

The flow rate sensor 35b is provided at a predetermined position on the connecting curved pipe 35a on the secondary side of each pump discharge port. The flow rate sensor 35b is provided individually for each pump, and the flow rate sensor 35b attached so as to detect an ascending flow uses a rotary impeller type flow rate sensor. The flow sensor 35b includes, for example, a body having a rotation axis orthogonal to the water flow direction, an impeller having a magnet portion rotatably provided by the water flow, and an alternation detection type Hall IC which is a magnetic detection element. Is provided so as to face the outer periphery of the magnet. The flow rate sensor 35b is connected to the control unit 41 via a signal line. The flow rate sensor 35b detects the flow rate of each pump and transmits a pulse signal proportional to the detected flow rate to the control unit 41. The flow rate sensor 35b may use another configuration such as a Karman vortex flow rate sensor that outputs a voltage or current proportional to the detected flow rate or a pulse signal.

The check valve 36 is provided on each of the individual discharge pipes 33 on the secondary side of the flow rate sensor 35b and on the primary side of the confluence with the discharge connecting pipe 34. The check valve 36 regulates the flow of the flow path in the individual discharge pipes in one direction from the primary side to the secondary side.

The ball valve 37 is provided on each individual discharge pipe on the secondary side of the flow rate sensor 35b and the check valve 36 and on the primary side of the confluence with the discharge connecting pipe 34. The ball valve 37 is an on-off valve that includes a ball that opens and closes the flow path by rotation and a lever that rotates the ball, and opens and closes the flow path by rotating the lever.

The discharge connecting pipe 34 is a pipe that forms a connecting flow path that communicates with the individual discharge flow paths in the plurality of individual discharge pipes 33, and extends in the first direction that intersects with the individual discharge pipes 33. The discharge connecting pipe 34 is connected to a water supply device such as a faucet which is a water supply destination. The discharge connecting pipe 34 is provided with a pressure detection unit 38 and a plurality of accumulators 39, respectively.

The pressure detection unit 38 includes a first pressure sensor 38a, a second pressure sensor 38b, and a pressure gauge 38c. The pressure sensors 38a and 38b are, for example, diaphragm type sensors, and detect the pressure in the flow path of the discharge connecting pipe 34. The pressure sensors 38a and 38b are connected to the control unit 41 of the control panel 14 via a signal line, and transmit the detected pressure signal to the control unit 41.

The first pressure sensor 38a and the second pressure sensor 38b are arranged in a direction perpendicular to the horizontally extending discharge connecting pipe 34. For example, the first pressure sensor 38a and the second pressure sensor 38b are arranged above the discharge connecting pipe 34, face downward, and are connected to an upper portion of the peripheral wall portion of the discharge connecting pipe 34. The first pressure sensor 38a and the second pressure sensor 38b face in the same direction and are arranged in parallel. For example, in the present embodiment, one end of the discharge connecting pipe 34 is closed by the closing flange 34b, and the pressure gauge 38c, the second pressure sensor 38b, and the first pressure sensor 38a are connected side by side from the closing flange 34b side.

The control unit 41 performs sensor switching control for switching the target sensor used for pump operation control. As an example, the control unit 41 uses one of the plurality of pressure sensors 38a and 38b as a main sensor used for pump operation control in a normal state, and as a sub-sensor used when detecting a failure of the main sensor, for pump operation control. In other words, if the failure condition is not satisfied, the operation control of the pump is performed using the main sensor as the target sensor, and if the failure condition is satisfied, the operation control of the pump is performed using the sub sensor as the target sensor.

The pressure gauge 38c displays the pressure measurement result obtained by measuring the pressure in the flow path of the discharge connecting pipe 34 by a mechanical mechanism such as a Bourdon pipe.

In the present embodiment, two pressure sensors 38a and 38b and a pressure gauge 38c are connected to a pipe portion on one side of the confluence of the individual discharge pipe and the discharge connecting pipe 34, respectively, and the two pressure sensors 38a and 38b are connected. And the pressure sensor 38c are arranged side by side in order in the extension direction of the discharge connecting pipe 34.

A plurality of accumulators 39, for example, two in the present embodiment, are provided, and are connected to the confluence points of the two individual discharge pipes 33 arranged on the secondary side of the discharge connection pipe 34 with the discharge connection pipe 34, respectively. Will be done.

The control panel 14 includes a control box, a control board housed in the control box, and an inverter. Further, various control devices such as an earth leakage breaker, a DC reactor, a power terminal block, and a noise filter are provided in the control box. It is also possible to add an expansion board. For example, a plurality of control boards, inverters, earth leakage breakers, DC reactors and power terminal blocks, and noise filters are provided corresponding to each of the plurality of pump devices 12.

The control board is a circuit board, and is equipped with various control devices such as a RAM (Random Access Memory) / ROM (Read Only Memory) as a storage device and a control unit 41.

The storage device includes, for example, a program memory, RAM, and a rewritable ROM. In the storage device, for example, various programs, calculation formulas, data tables, reference values, threshold values, and the like are stored as information necessary for control.

The control unit 41 includes a processor. The control unit 41 controls the operation of the plurality of pump devices 12 according to various programs stored in the storage device in advance based on the information detected by various detection devices such as the flow rate sensor 35b and the pressure sensors 38a and 38b. Specifically, the control unit 41 transmits a control signal to a plurality of inverters and controls the inverters corresponding to each pump device 12.

For example, the control unit 41 performs various arithmetic processes based on the detected values detected by the various sensors 38a, 38b, and 35b, and shifts the motor 21 of the pump device 12 or stops it by controlling the frequency of the inverter. Specifically, the control unit 41 performs constant discharge pressure control or constant estimated terminal pressure control so that the discharge pressure detected by the target sensor of any of the pressure sensors 38a and 38b becomes a predetermined target pressure H. Then, the pressure feedback control is used to control the rotation speed and stop operation.

As a normal operation process, the control unit 41 detects the pressure value and the flow rate value detected by various detection devices such as the flow rate sensor 35b and the pressure sensors 38a and 38b, and performs feedback control based on the flow rate and the pressure. Specifically, the control unit 41 drives one or more pump devices 12 by outputting a control signal to each inverter based on the discharge pressure detected in the discharge flow path and the target pressure H. .. The inverter outputs a predetermined frequency according to the control signal to rotate the motor 21 of the pump device 12 at a predetermined rotation speed.

As an example of the operation control of the pump device 12, the control unit 41 performs constant discharge pressure control with a predetermined set pressure P1 as the target pressure H. Alternatively, as another example of the normal operation control, the control unit 41 performs the estimated terminal pressure constant control with the fluctuation value between the estimated terminal pressure P2 and the preset set pressure P1 as the target pressure H.

Further, in the operation control of the pump device 12, the control unit 41 satisfies a predetermined increase condition while operating the pump device 12 of any of the plurality of pump devices 12, for example, the operating frequency is a predetermined upper limit frequency. In the case of, the standby pump device 12 is activated to increase the number of units. Further, the control unit 41 stops the starting pump and reduces the number of units when the predetermined reduction of units condition is satisfied, for example, when the amount of water supplied detected by the plurality of flow rate sensors 35b becomes equal to or less than the predetermined flow rate. Perform processing. Further, the control unit 41 stops the rotation of the pump when a predetermined stop condition is satisfied. For example, when one pump is independently operated and the discharge flow rate of each pump device 12 detected by the flow rate sensor 35b provided on the individual discharge pipe 33 is lower than the predetermined stop flow rate, the pump is stopped by a small amount of water.

Further, in the present embodiment, the control unit 41 detects the operation frequency f0 at the time of a small amount of water when each pump device that has been independently operated stops at a small amount of water every time, and after the power of each pump is turned on. The operation frequency f0'at the time of the first small amount of water is stored, and further, the operation frequency f0 at the time of the small amount of water when each pump stops the small amount of water is stored / updated after the second time.

The control unit 41 performs sensor switching control for switching the pressure sensor used for the operation control of the pump device 12. As sensor switching control, for example, the control unit 41 sets one of the plurality of pressure sensors 38a and 38b as a main sensor and the other as a sub sensor, and in a normal state, for example, when a predetermined failure condition is not satisfied, the main sensor The operation control of the pump device 12 is performed using the measurement result, and when a failure satisfying a predetermined failure condition is performed, the operation control of the pump device 12 is performed using the measurement result of the sub-sensor.

For example, in the present embodiment, the first pressure sensor 38a is the main sensor, the second pressure sensor 38b is the sub sensor, and the control unit 41 is the first discharge pressure Ps1 detected by the first pressure sensor 38a, which is the main sensor. In the state of operation control, first, when the amount of water supplied decreases and the operation pump is stopped by a small amount of water, the first pressure sensor 38a or the first pressure sensor 38a is compared with the signal level from the second pressure sensor 38b which is a sub sensor. It is determined that a failure has occurred in the second pressure sensor 38b.

For example, when the difference between the second discharge pressure Ps2, which is the detection pressure in the sub sensor, and the first discharge pressure Ps1 detected by the first pressure sensor 38a, the control unit 41 is a predetermined pressure deviation Δh or more. 1 It is determined that a failure has occurred in the pressure sensor 38a or the second pressure sensor 38b.

The pressure deviation Δh is set with reference to the pressure set in the control unit 41. For example, in the present embodiment, for example, the estimated terminal pressure P2 used for the target pressure H is multiplied by a predetermined coefficient k1 (for example, 0.02 to 0.10.).

FIG. 5 is an explanatory diagram showing an example of setting each reference value and the correspondence between the head and the voltage. In this embodiment, as the pressure sensors 38a and 38b, for example, a sensor having a maximum working pressure of 3 MPa (= 306 m) was used. The set pressure P1 was 250 m, the estimated terminal pressure P2 was 225 m, and the coefficient k1 was 0.03. In this case, the pressure deviation Δh is 7 m (deviation voltage 0.09 V), the upper limit reference value lift is 232 m, the input voltage is 4.03 V, the lower limit reference value lift is 218 m, and the input voltage is 3.85 V. Therefore, the failure detection can be performed earlier than the conventional failure detection method in which 5.000V, which is the input voltage of the upper limit of the measurement of the pressure sensor, is used as the threshold reference for the failure detection of the pressure sensor. Further, the control unit 41 determines which pressure sensor has failed based on the operating frequency when the small amount of water is stopped. The control unit 41 detects the operating frequency f0 at the time of small water volume before stopping the corresponding pump, calculates the deviation from the operating frequency f0'at the first small water volume of the corresponding pump, and the frequency deviation f is a predetermined predetermined value. When the frequency deviation is Δf or more, it is determined that the first pressure sensor 38a has failed.

The frequency deviation Δf is set with reference to the operating frequency f0'when each pump first stops with a small amount of water after the power is turned on. For example, in the present embodiment, the frequency deviation Δf is, for example, a value obtained by multiplying the operation frequency f0'when the first small amount of water is stopped by a predetermined coefficient k2 (for example, 0.01 to 0.05).

FIG. 6 is an explanatory diagram showing the correspondence between each reference value and the operating frequency when the small amount of water is stopped. In the present embodiment, the operating frequency f0'when the first small amount of water is stopped is 197.5 Hz, and the coefficient k2 is 0.015. In this case, the frequency deviation Δf is 3.0 Hz, the upper limit reference value f1 is 200.5 Hz, and the lower limit reference value f2 is 194.5 Hz. Since the generated pressure of the pump is approximately the square of the operating frequency during small water volume operation, the coefficients k1 and k2 are determined ^{so that (1 + k2) 2 ≈ (1 + k1).}

When the control unit 41 determines that the first pressure sensor 38a, which is the main sensor, has failed, it sends an alarm signal to notify the abnormality of the first pressure sensor 38a, and the second pressure sensor 38b, which is a sub sensor, notifies the abnormality. A pressure sensor switching process for switching to perform pressure control is performed, and subsequent operation control of the pump device 12 uses the second discharge pressure Ps2 detected by the second pressure sensor 38b. Specifically, the target pressure constant control or the estimated terminal pressure constant control is performed based on the predetermined target pressure H and the second discharge pressure Ps2.

Further, the control unit 41 calculates the deviation between the operating frequency f0 at the time of small water volume and the operating frequency f0'at the time of the initial small water volume, and when the frequency deviation f is less than a predetermined frequency deviation Δf. The first pressure sensor 38a is normal, determines that the second pressure sensor 38b has failed, and notifies the abnormality of the second pressure sensor 38b.

Each inverter is electrically connected to the motor 21 of the pump device 12 by a signal line. The inverter outputs a predetermined frequency according to the control signal from the control unit 41 to rotate the motor 21 of the pump device 12 at a predetermined rotation speed.

According to the water supply device 10 according to the present embodiment, by performing a double check of pressure and operating frequency, a failure of the main pressure sensor in use is detected quickly and reliably, and backup is performed by the sub pressure sensor. The effect of being able to shift to driving can be obtained. That is, in the water supply device 10, two pressure sensors are used, and the pressure signal is the rated output of the pressure sensor by determining the occurrence of a failure from the deviation between the value of one pressure sensor and the value of the other pressure sensor. Compared with the conventional method in which the failure condition is out of the range, the effect that the failure detection can be started quickly can be obtained. Further, in the water supply device 10, the failure range of the pressure sensor is set to a value obtained by multiplying the estimated terminal pressure P2 by k1 (0.02 to 0.10) based on the estimated terminal pressure P2, and therefore the rating of the pressure sensor to be used. Even if the range is different, the effect that it is not necessary to set for each model can be obtained.

As a comparative example, for example, in the case of a water supply device whose failure condition is when the pressure signal deviates from the rated output range of the pressure sensor, the output voltage range of the normal pressure sensor is the upper limit voltage of 5.0 V (at the maximum pressure). Since the lower limit voltage is 1.0 V (at 0 m), the voltage range that cannot be determined as a failure is too wide, and it becomes difficult to detect defects such as pipe leakage, power consumption, and water outage due to high pressure. For example, if the output voltage of the pressure sensor is 1 to 5V with respect to 0 to 306m, when it is determined that the output voltage of the pressure sensor is 0.5V or less or more than 5V, the lower limit value 1V = 0 m may be detected when the water cannot be pumped, and it may not be a failure of the pressure sensor. However, when the output voltage of the pressure sensor drops below the standard output voltage, it is judged that the pressure is insufficient and the operation is performed. Increasing the frequency can cause abnormally high pressure in the small water range. On the other hand, the upper limit value of 5V for failure detection is a value that is not output unless the power supply circuit inside the pressure sensor fails, but if it is judged that the pressure is high and the frequency is lowered when it exceeds 5V, the water is cut off due to insufficient pressure. there is a possibility.

That is, in the case of the conventional failure detection method, since the output voltage is out of the rated range, the failure can be reliably detected, but on the other hand, when the failure is detected, the power supply circuit fails and a high voltage is output. In addition, there were problems such as the diaphragm being damaged and almost no discharge pressure being received.

The control method of the water supply device according to the present embodiment will be described by using the flowcharts shown in FIGS. 7 to 9. First, after the power is turned on, the operating frequency f0'at the first stop of the small amount of water of each pump device is detected. I remember (ST124). Then, the operating frequency f0 when the small amount of water is stopped is detected and stored even after the second time of each pump device (ST123).

Then, in the control routine in which the number of operating units is one (ST121), the amount of water supplied decreases to be equal to or less than the stop flow rate, and when the operation pump is stopped by a small amount of water (ST122), the signal level of the second pressure sensor is detected (ST122). ST126), the pressure deviation between the signal levels of the first pressure sensor and the second pressure sensor is calculated (ST127), and when the pressure deviation is equal to or greater than the predetermined pressure deviation Δh (ST128), one of the pressure sensors fails. Is determined to have occurred. If the pressure sensor abnormality flag is set and the abnormality of the first or first pressure sensor is detected, that is, if the pressure sensor abnormality flag is ON (Yes in ST125), each step is skipped and the amount of small water is small. Proceed to the stop step (ST135). For example, when the signal level of the first pressure sensor when the small amount of water is stopped is equivalent to 225 m of the estimated terminal pressure P2, but the signal level of the second pressure sensor is as low as 215 m (h = 10 m), the second pressure sensor There is a possibility that low pressure is detected because the power supply circuit of is deteriorated and its output drifts. That is, at this point, it is unknown which of the first pressure sensor and the second pressure sensor is out of order, but the failure of either of the pressure sensors can be detected at an early stage.

Then, in the next step, by comparing the operating frequency at the time of the first small water amount stop of the corresponding pump in which the first pressure sensor was normal and the operating frequency at the time of the current small water amount stop for the same target pressure, Judgment of pressure sensor failure.

That is, the deviation f (= 3.5 Hz) between the first operation frequency f0'(197.5 Hz) when the small amount of water is stopped and the operation frequency f0 (201 Hz) when the small amount of water is stopped this time is calculated (ST129) and determined in advance. Since the frequency deviation is greater than or equal to the predetermined frequency deviation Δf (= 3 Hz), it is tentatively determined that the first pressure sensor 38a has failed, and 1 is subtracted from the set first pressure sensor abnormality counter Cp1 (initial value> 1) (ST131). ). The initial values of Cp1 and Cp2 are integers larger than 1 (example: 3 times).

Then, the above pressure deviation comparison is performed every time the small amount of water of the operating pump is stopped a plurality of times (ST129), and when the above-mentioned first pressure sensor abnormality counter Cp1 becomes zero (Cp1 = 0) ( Yes) of ST132, an alarm signal notifying the abnormality of the first pressure sensor 38a is sent to the outside, and the subsequent operation control uses the second discharge pressure Ps2 detected by the second pressure sensor 38b which is a sub sensor. (ST133).

On the other hand, when the operating frequency f0 when the small amount of water is stopped this time is 198.5 Hz, the deviation f = 1.0 Hz is calculated and the frequency deviation is less than Δf (= 3 Hz), so that the second pressure sensor 38b fails. Is provisionally determined, and 1 is subtracted from the set second pressure sensor abnormality counter Cp2 (initial value> 1) (ST136).

Then, when the small water volume of the operating pump is stopped a plurality of times, the operating frequencies of the different pumps are compared, and when the second pressure sensor abnormality counter Cp2 becomes zero (Cp2 = 0) ( Yes) of ST137, an alarm signal for notifying an abnormality of the second pressure sensor 38b is sent.

Therefore, rather than determining a failure based only on the detected pressure = voltage signal, it is possible to quickly and reliably determine the failure, and it is possible to obtain an effect that automatic operation by a normal pressure sensor is possible.

The first pressure sensor abnormality counter Cp1 or the second pressure sensor abnormality counter Cp2 becomes zero (Yes in ST132, Yes in ST137), the multiple determination processes are completed, and one of the pressure sensors has an abnormality. When is confirmed, the pressure sensor abnormality flag indicating that the pressure sensor abnormality has been detected is turned on (ST134).

As a result, for example, if the amount of leakage increases due to wear of the seal part of the pump, the operating frequency may increase in order to maintain the generated pressure, but it can be verified by comparing the operating frequencies of different pumps, so it is erroneously determined. There is no fear.

Further, for the control panel of the water supply device 1, it is possible to use the control unit of the control panel for the direct water supply device which is directly connected to the water pipe and has one pressure sensor on the discharge side and one pressure sensor on the suction side. Therefore, the manufacturing cost can be suppressed.

According to the above-described embodiment, it is possible to provide a water supply device and a control method of the water supply device that can quickly and surely determine a failure and shift to automatic operation by a normal pressure sensor.

The present invention is not limited to the above embodiment, and the configuration of each part, various conditions, and specific set values can be appropriately changed.

For example, in the above embodiment, the first pressure sensor 38a, which is the main sensor that is always used, is constantly energized, and the pump device is operated and controlled so that the detected first discharge pressure Ps1 becomes the target pressure, and is a sub-sensor. The second pressure sensor 38b may be energized when the operation pump is stopped by a small amount of water to calculate the deviation of the signal level from the first pressure sensor 38a and the second pressure sensor 38b. As a result, the operating time of the power supply circuit of the second pressure sensor 38b is drastically reduced, so that the electrical life can be extended.

For example, in the above embodiment, both the first pressure sensor 38a and the second pressure sensor 38b are oriented in the vertical direction orthogonal to the horizontally extending discharge connecting pipe 34, and are connected downward to the upper part of the discharge connecting pipe 34. However, it is not limited to this.

For example, in the water supply device 10A shown in FIG. 10 as another embodiment, one end of a horizontally extending discharge connecting pipe 34 is closed, and a first pressure sensor 38a is horizontally attached to the closed one end. That is, the first pressure sensor 38a is oriented in the horizontal direction along the axial direction of the discharge connecting pipe 34 and is connected to the end of the discharge connecting pipe 34. On the other hand, the second pressure sensor 38b is arranged along the vertical direction above the middle portion of the discharge connecting pipe 34 and is connected to a part of the upper part of the peripheral wall of the discharge connecting pipe 34, as in the first embodiment. Has been done.

According to the present embodiment, by connecting the first pressure sensor 38a, which is the main sensor, horizontally and the second pressure sensor 38b, which is the sub sensor, vertically, the first pressure sensor 38a is in the horizontal posture, so that the discharge connection is established. The air in the flow path of the ball valve between the pipe 34 and the ball valve flows out as bubbles and responds well to transient pressure fluctuations, but the second pressure sensor 38b and the air flow out. The air in the flow path of the ball valve between the discharge connecting pipe 34 does not flow out, and the air layer remains for a long period of time. Therefore, this air layer makes it possible to protect the second pressure sensor 38b from a shocking pressure rise caused by, for example, a water hammer. This makes it possible to extend the mechanical life of the diaphragm portion of the second pressure sensor 38b, which is a sub-sensor.

Further, as another embodiment, the second pressure sensor 38b may be provided in the vicinity of the accumulator 39 as in the water supply device 10B shown in FIG. For example, in the water supply device 10B, the discharge connecting pipe 34 includes a connecting flow path 34c that branches horizontally from a part of the peripheral wall, and an accumulator 39 is connected to the other end side of the connecting flow path 34c via a ball valve. ing. A drain pipe is provided on the other end side of the connection flow path 34c. The connection flow path 34c is a small-diameter flow path that is connected to a part of the peripheral wall of the discharge connection pipe 34 extending in the horizontal direction, branches from the discharge connection pipe 34, and extends horizontally. The second pressure sensor 38b is connected to the middle part of the connection flow path 34c that connects the discharge connecting pipe 34 and the accumulator 39. The second pressure sensor 38b is arranged upward along the vertical direction above the horizontally extending connection flow path 34c, and is connected to the upper region of the peripheral wall of the connection flow path 34c.

On the other hand, the first pressure sensor 38a is arranged along the vertical direction above the middle portion of the discharge connecting pipe 34 and is connected to a part of the upper part of the peripheral wall of the discharge connecting pipe 34, as in the first embodiment. Alternatively, as in the second embodiment, the discharge connecting pipe 34 may be oriented in the horizontal direction along the axial direction and connected to the end of the discharge connecting pipe 34.
Further, the pressure gauge 38c is arranged and connected in the vertical direction above the middle portion of the discharge connecting pipe 34 as in the first embodiment.

In the water supply device 10B according to the present embodiment, the second pressure sensor 38b is arranged in the vicinity of the accumulator 39, so that the air layer in the accumulator 39 causes a shocking pressure increase due to, for example, a water hammer. It is possible to protect the pressure sensor 38b. This makes it possible to extend the mechanical life of the diaphragm portion of the second pressure sensor 38b, which is a sub-sensor.

The present invention is not limited to the above embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate, in which case the combined effect can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent requirements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the problem can be solved and the effect is obtained, the configuration in which the constituent requirements are deleted can be extracted as an invention.

10, 10A, 10B ... Water supply device, 11 ... Base, 11b ... Anti-vibration stand, 11c ... Control board stand, 12 ... Pump device, 13 ... Piping unit, 14 ... Control board, 21 ... Motor, 22 ... Pump section, 24 ... Casing, 31 ... Suction side pipe, 32 ... Discharge side pipe, 33 ... Individual discharge pipe, 34 ... Discharge connecting pipe, 34b ... Closing flange, 34c ... Connecting flow path, 35a ... Connecting curved pipe, 36 ... Check valve, 37 ... ball valve, 38 ... pressure detection unit, 38a ... first pressure sensor, 38b ... second pressure sensor, 38c ... pressure gauge, 39 ... accumulator, 41 ... control unit.

Claims (6)

With the pump device
A piping unit having a discharge side pipe connected to the discharge side of the pump device, and
A pressure detection unit having a first pressure sensor and a second pressure sensor for detecting the pressure of the discharge side pipe,
With the first pressure sensor, the discharge pressure constant control with the predetermined set pressure P1 as the target pressure, or the estimated terminal pressure constant control with the value between the predetermined set pressure P1 and the estimated terminal pressure P2 as the target pressure. The operation of the pump device is controlled so that the detected first discharge pressure becomes the target pressure, and the operation frequency f0 at the time of a small amount of water when each pump device stops with a small amount of water is detected and stored every time.
In the state of operating with the first pressure sensor, when the amount of water supplied decreases and the operation pump is stopped by a small amount of water, the pressure deviation which is the deviation between the signal levels of the first pressure sensor and the second pressure sensor. When the pressure deviation is equal to or greater than a predetermined pressure deviation Δh, the frequency deviation f between the operating frequency f0 at the time of small water volume and the operating frequency f0'at the initial small water volume of the corresponding pump is further calculated. When the frequency deviation f is calculated and is equal to or greater than a predetermined frequency deviation Δf, the abnormality of the first pressure sensor is sent to the outside and the abnormality is sent to the outside.
A water supply device including a control unit that performs a sensor switching process for controlling the operation of the pump device using the second discharge pressure detected by the second pressure sensor. When the deviation between the operating frequency f0 at the time of small water volume and the operating frequency f0'at the first small water volume of the corresponding pump is calculated and the frequency deviation f is less than a predetermined frequency deviation Δf, the second The water supply device according to claim 1, wherein an abnormality of the pressure sensor is sent to the outside. The water supply according to claim 1 or 2, wherein when the small amount of water of the operating pump is stopped a plurality of times, the pressure deviation is compared and the operating frequency is compared to determine the abnormality of the first pressure sensor or the second pressure sensor. apparatus. The first pressure sensor is attached to the discharge side pipe in the vertical direction.
The water supply device according to any one of claims 1 to 3, wherein the second pressure sensor is attached to the discharge side pipe in a horizontal direction. Equipped with an accumulator connected to the discharge side pipe
The first pressure sensor is attached to the discharge side pipe and is attached to the discharge side pipe.
The water supply device according to any one of claims 1 to 3, wherein the second pressure sensor is attached to a connection flow path between the discharge side pipe and the accumulator. By constant discharge pressure control with the predetermined set pressure P1 as the target pressure, or with constant estimated terminal pressure control with the value between the predetermined set pressure P1 and the estimated terminal pressure P2 as the target pressure.
The operation of the pump device is controlled so that the first discharge pressure detected by the first pressure sensor that detects the pressure of the discharge flow path connected to the discharge side of the pump device becomes the target pressure.
The operating frequency f0 at the time of a small amount of water when each pump device stops with a small amount of water is detected and stored each time, and the amount of water supplied decreases and the operating pump is reduced in the state of being operated by the first pressure sensor. When the amount of water is stopped, the deviation of the signal level from the first pressure sensor and the second pressure sensor is calculated, and if the pressure deviation is equal to or more than a predetermined pressure deviation determined in advance, the operating frequency when the amount of water is small is further determined. , The frequency deviation from the operating frequency at the time of the first small amount of water of the corresponding pump is calculated, and when the frequency deviation is equal to or more than a predetermined frequency deviation determined in advance, the second discharge pressure detected by the second pressure sensor is calculated. A method for controlling a water supply device, which performs a sensor switching process for controlling the operation of the pump device.