JP7224887B2 - Increased pressure water supply device and control method for increased pressure water supply device - Google Patents

Description

The present invention relates to a pressurized water supply system and a control method for the pressurized water supply system.

BACKGROUND ART Booster water supply systems are required to have a so-called high water distribution pressure stop function that stops the pump when the suction pressure rises during operation of the pump.

Such a pressurized water supply apparatus includes a pump, a motor, a pressure reducing valve type backflow prevention device provided in a flow path on the primary side of the pump, an accumulator provided on the secondary side of the pump, and piping A known pump includes a suction pipe on the primary side of the pump, a discharge pipe on the secondary side of the pump, and a bypass pipe that connects the suction pipe and the discharge pipe (see, for example, Patent Document 1). The suction pipe is provided with a strainer, a shut-off valve, and a pressure sensor to detect the pressure in the suction pipe, that is, the pressure on the primary side of the backflow prevention device.

For example, in a pressurized water supply system in which the suction pressure is positive, if the suction pressure rises above the target pressure during pump operation, the pump is automatically stopped and direct pressure water is supplied via the bypass flow path and the pump. The functions are specified in the standards of the Japan Water Works Association.

Patent No. 3287528

In this case, for example, if the minimum pressure loss of the stop valve, strainer, and pressure reducing valve type backflow prevention device is about 6 m, the pressure on the discharge side of the pump (hereinafter referred to as discharge pressure) when the pump is stopped is "target The pressure drops to -6 m". On the other hand, in the case of the constant discharge pressure control method, the starting pressure is about "target pressure -4m". Therefore, when the water stored in the accumulator flows out during operation of the pump and the discharge pressure drops to "target pressure -4 m", a hunting phenomenon may occur in which the pump restarts. Therefore, it is possible to set a margin considering the pressure loss, but the pressure loss of the shut-off valve, strainer, and pressure reducing valve type backflow prevention device changes in a complicated manner according to the diameter of the valve and the amount of water supply. It is difficult to set the

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a pressurized water supply apparatus capable of stable control and a method for controlling the pressurized water supply apparatus.

A pressurized water supply apparatus according to one aspect of the present invention comprises: a pump; a backflow prevention device arranged on a primary side of the pump and connected to a water pipe; a pump suction pressure detection unit for detecting the pump suction pressure on the suction side of the pump, a discharge pressure detection unit arranged on the secondary side of the pump for detecting the discharge pressure on the discharge side of the pump, and a discharge pressure detection unit arranged on the discharge flow path , With a flow rate detection unit that outputs a signal proportional to the water supply amount and an estimated terminal pressure constant control method, in the flow range from the stop flow rate to the rated flow rate, the second target pressure at the stop flow rate to the first at the rated flow rate The output of the pump is controlled up to the target pressure based on the target pressure that fluctuates with an increase in the flow rate, and the pump suction pressure exceeds the target pressure that fluctuates according to the amount of water supply during operation of the pump. continues for a certain period of time, it is determined that the water distribution pressure is high, and the pump is stopped even if the flow rate detected by the flow rate detection section exceeds the stop flow rate.
A control method for a booster water supply apparatus according to another aspect of the present invention includes a pump, a backflow prevention device arranged on the primary side of the pump and connected to a water pipe, and between the backflow prevention device and the pump. a pump suction pressure detection unit arranged on the suction side of the pump for detecting the pump suction pressure on the suction side of the pump; a discharge pressure detection unit arranged on the secondary side of the pump for detecting the discharge pressure on the discharge side of the pump; A pressurized water supply device that is arranged in a flow path and has a flow rate detector that outputs a signal proportional to the amount of water supply. from the second target pressure at rated flow to the first target pressure at rated flow, the output of the pump is controlled based on the target pressure that fluctuates with an increase in flow rate, and during pump operation, the pump suction pressure If the target pressure, which fluctuates according to the amount, is exceeded for a certain period of time, it is determined that the water distribution pressure is high, and the pump is stopped even if the flow rate detected by the flow rate detection unit exceeds the stop flow rate. do.

ADVANTAGE OF THE INVENTION According to this invention, the control method of the pressure increase water supply apparatus which can be controlled stably and a pressure increase water supply apparatus can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a pressurized water supply device according to one embodiment of the present invention; Explanatory drawing of the same pressure increase water supply apparatus. The side view of the same pressure increase water supply apparatus. The graph which shows the target pressure of the pressure increase water supply apparatus. Explanatory drawing of the boosting water supply apparatus concerning other embodiment.

A pressurized water supply apparatus 1 and a control method for the pressurized water supply apparatus 1 according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 and 2 are explanatory diagrams of the booster water supply apparatus 1, showing the internal structure with the cover cut away and a front view showing a part of the structure in cross section. FIG. 3 is a side view of the pressure increasing water supply device 1, and FIG. 4 is a graph showing the target pressure in the control of the pressure increasing water supply device 1, showing the relationship between the lift and the flow rate during the estimated terminal pressure constant control.

As shown in FIGS. 1 to 3, the booster water supply device 1 is a direct water supply device connected to a water pipe 10, and includes a plurality of pump devices 11, a pipe 12, a backflow prevention device 13, An accumulator 14, a first pressure sensor 15 as a pump suction pressure detection section, a second pressure sensor 16 as a discharge pressure detection section, a flow rate sensor 17 as a flow rate detection section, and an electrical component section 18, and these are accommodated. A pump cover 19 is provided. The water pipe 10 is, for example, a water main or a water branch.

The pump device 11 includes a motor 21 and a one-stage or multi-stage pump 23 having an impeller connected to the motor 21 to increase the pressure of the fluid and pump it to the secondary side. In the present embodiment, an example in which a pair of multi-stage pump devices 11 are installed vertically is shown.

The pump 23 has a pump suction port 23a at its lower end and a pump discharge port 23b at its upper side. A suction connecting pipe 32 of the pipe 12 is connected to the pump suction port 23a. An individual discharge pipe 34 forming an individual discharge flow path is connected to the pump discharge port 23b.

Each motor 21 is connected to the control section 18b of the electrical section 18 via a cable. The operation of the pump device 11 is controlled by driving the motor 21 under the control of the controller 18b.

The pipe 12 includes a suction pipe 31 arranged on the primary side of the backflow prevention device 13 , a suction connection pipe 32 arranged on the secondary side of the backflow prevention device 13 , and branched from the suction connection pipe 32 to each pump 23 . A pair of ball valve portions 33 leading to the pump suction port 23a, a plurality of individual discharge pipes 34 connected to the pump discharge port 23b of the pump 23, and a discharge connection connecting the plurality of individual discharge pipes 34 and the ball valve portion 33. A pipe 35 and a bypass connecting pipe 36 connecting the discharge connecting pipe 35 and the suction connecting pipe 32 are provided.

The suction pipe 31 has a suction port 12a at the end on the primary side. A strainer 37 is provided near the suction port 12a. The other end of the suction pipe 31 is connected to the backflow prevention device 13 .

The backflow prevention device 13 is a pressure reducing valve type backflow prevention device provided in the flow path on the primary side of the pump, and is provided between the suction pipe 31 and the suction connecting pipe 32 . The backflow prevention device 13 includes a first check valve 13a, a second check valve 13b, a retainer 13c, and a relief valve, and regulates the direction of liquid flow in the channel to one direction.

The suction connecting pipe 32 is a tubular member and is connected to the secondary side of the backflow prevention device 13 . The suction connecting pipe 32 extends horizontally below the two pump devices 11, for example. The suction connecting pipe 32 is provided with a first pressure sensor 15 as a first pressure detector. The first pressure sensor 15 detects the pressure in the suction connecting pipe 32, that is, the pressure Ps1 on the secondary side of the backflow prevention device 13 and on the primary side of the pump device 11 (hereinafter referred to as pump suction pressure Ps1).

The pair of ball valve portions 33 are connected to the pump suction ports 23a of the pair of pumps 23, respectively. The ball valve portion 33 forms a channel that communicates between the suction connecting pipe 32 on the primary side and the pump suction port 23a.

The individual discharge pipe 34 is a tubular member, one end of which is connected to a pump discharge port 23 b arranged on the side wall of the pump 23 . The individual discharge pipe 34 extends forward from the pump discharge port 23b, bends and extends downward, and is connected to a discharge connecting pipe 35 provided below. A check valve 52 that restricts the flow direction to one direction is provided at a predetermined location within the individual discharge pipe 34 and close to the pump discharge port. A flow rate sensor 17, which is a flow rate detection section for detecting the flow rate of the liquid in the individual discharge pipe 34, is provided in each of the individual discharge pipes 34 in the middle.

The discharge connecting pipe 35 is a tubular member and is connected to the secondary side of the ball valve portion 33 connected to the plurality of individual discharge pipes 34 . The discharge connecting pipe 35 extends horizontally, for example, below the two vertically arranged pump devices 11 and is arranged in parallel with the suction connecting pipe 32 . One end of the discharge connecting pipe 35 is closed, and the other end has a discharge port 12b connected to a water supply destination such as a faucet. The discharge connecting pipe 35 is provided with a second pressure sensor 16 as a second pressure detector. The second pressure sensor 16 detects the pressure in the discharge connecting pipe 35, that is, the pressure Ps2 on the secondary side of the pump 23 (hereinafter referred to as discharge pressure Ps2). An accumulator 14 for accumulating pressure is provided near the discharge port of the discharge connecting pipe 35 .

The bypass connecting pipe 36 is a tubular member and forms a bypass flow path that connects the discharge connecting pipe 35 and the suction connecting pipe 32 . A check valve 51 that restricts the flow direction to one direction is provided at a predetermined location in the bypass connecting pipe 36 .

The first pressure sensor 15 and the second pressure sensor 16 are, for example, semiconductor pressure sensors that utilize the piezo effect. The pressure sensors 15 and 16 are composed of a diaphragm provided in the hole of the sensor body, a strain gauge provided above the diaphragm, a liquid chamber provided between the diaphragm and the strain gauge, and a liquid chamber filled with and a non-corrosive liquid, such as silicone oil.

The first pressure sensor 15 and the second pressure sensor 16 are configured to detect the pressure inside the pipe 12 and output an analog voltage. The first pressure sensor 15 and the second pressure sensor 16 detect that when the diaphragm changes due to the pressure in the pipe 12, pressure is applied to the strain gauge by silicone oil in the liquid chamber, and the amount of strain in the strain gauge corresponding to the pressure is applied. is converted into a signal to detect the pressure. The first pressure sensor 15 and the second pressure sensor 16 are connected to the control section 18b of the electrical component section 18 via signal lines, and send detected pressure signals to the control section 18b.

The flow rate sensor 17 is, for example, a rotary sensor having an impeller provided with a magnet and detecting the flow rate with a Hall IC connected to the magnet.

The electrical unit 18 includes a storage device 18a as a storage unit that stores various information, a control unit 18b, and a plurality of inverters 18c connected to each pump.

The storage device 18a stores, for example, various programs, various reference values, thresholds, and the like as information necessary for control. For example, the storage device 18a stores numerical values such as target pressure, starting pressure, variation reference value ΔPv, first reference value Pt1 and second reference value Pt2, calculation formulas, data tables, etc., as information necessary for control. ing.

The target pressure Pdv is a set value determined based on various conditions, and is set as a predetermined fixed value or variable value. In the present embodiment, as an example, the target pressure Pdv is the target pressure used for the estimated terminal pressure constant control. For example, as shown in FIG. A value on the target pressure curve L1 that fluctuates with an increase in the output frequency or the flow rate from the pressure to the first target pressure at the rated flow rate.

The starting pressure is a set value determined based on various conditions of the pump device, and is set to a predetermined value lower than the target pressure. As a specific example, the starting pressure is set based on the second target pressure Pd2, which is the minimum target pressure. This embodiment shows an example in which the starting pressure is set to 20 m, which is 4 m lower than the second target pressure Pd2, which is the minimum target pressure.

The first reference value Pt1 is a set value determined based on various conditions, and is set to a positive pressure, for example. As an example, the first reference value Pt1 is set to 0.01 MPa in this embodiment.

The second reference value Pt2 is a set value determined based on various conditions, and is set to a positive pressure higher than the first reference value Pt1, for example. As an example, the second reference value Pt2 is set to 0.04 MPa in this embodiment.

The durations t1 and t2 are set according to various conditions. For example, t1 and t2 are predetermined values of 1 second or more, and this embodiment shows an example in which both t1 and t2 are set to 3 seconds.

The control unit 18b controls operations of the plurality of pump devices 11 according to various programs stored in advance in the storage device 18a. Specifically, the control unit 18b transmits a control signal to each inverter 18c to control the inverter 18c corresponding to each pump device 11 . For example, the control unit 18b performs various arithmetic processing based on the detection values detected by the sensors, and controls the frequency of the inverter 18c to change the speed of the motor 21 of the pump device 11 or stop it. Specifically, the control unit 18b performs constant estimated terminal pressure control so that the discharge pressure reaches a target pressure that varies according to the amount of water supply. For example, the discharge pressure is feedback-controlled based on the variable target value as shown in FIG.

The inverter 18c is electrically connected to the motor 21 of the pump device 11 through a signal line. The inverter 18c rotates the motor 21 of the pump device 11 at a predetermined rotational speed by outputting a predetermined frequency according to the control signal from the control section 18b.

Next, a method for controlling the boosted water supply device 1 according to this embodiment will be described.

Control unit 18b detects an instruction to operate pump device 11 . When the control unit 18b detects an instruction to operate the pump device 11 by an external input instruction or the like, the control unit 18b detects various data and starts operating the pump.

The control unit 18b detects pressure values and flow values detected by various pressure sensors and flow sensors.

The control unit 18b drives the pump device 11 by outputting a control signal to the inverter 18c. Here, two pump devices 11 are alternately operated. The inverter 18c outputs a predetermined frequency according to the control signal, thereby rotating the motor 21 of the pump device 11 at a predetermined rotational speed. At this time, the control unit 18b controls the estimated end pressure to be constant so that the discharge pressure Pd becomes the target pressure Pdv that varies according to the amount of water supply.

Specifically, the control unit 18b detects a fluctuation amount ΔPs1 of the pump suction pressure Ps1 per certain period of time (eg, one second), and determines whether or not the fluctuation amount ΔPs1 is equal to or greater than a predetermined fluctuation reference value ΔPv. do.

Then, when the fluctuation amount ΔPs1 of the pump suction pressure is less than a predetermined fluctuation reference value ΔPv, the discharge pressure is feedback-controlled with respect to the target pressure Pdv that fluctuates according to the output frequency or flow rate increase.

Specifically, as shown in the graph of FIG. 4 as an example, the control unit 18b changes the target pressure according to the value of the flow detected by the flow sensor 17 in the flow range from the stop flow to the rated flow. , the output of the pump is controlled based on the target pressure on the target pressure curve L1 of the estimated constant terminal pressure control.

On the other hand, when the fluctuation amount ΔPs1 of the pump suction pressure Ps1 becomes equal to or greater than the predetermined fluctuation reference value ΔPv, the target pressure is fixed for a predetermined time so that the target pressure does not fluctuate for the predetermined time t1, and the pump operation is controlled. I do. That is, the target pressure is fixed until the fixed time t1 elapses. That is, as shown in the graph of FIG. 4, the target pressure is fixed when the fluctuation value exceeds a certain value. Thereafter, after a certain period of time t1 has passed, the estimated terminal pressure constant control is performed again according to the target pressure on the target pressure curve L1. t1 is set to about 3 seconds, for example.

Since the target pressure does not change even if the suction pressure fluctuates, stable operation can be performed on the target pressure curve L1 of the estimated terminal pressure constant control.

Further, the control unit 18b determines whether or not the pump suction pressure Ps1 detected during operation of the pump satisfies the high water distribution pressure condition. Here, the high water distribution is a state in which the pressure on the suction side is equal to or higher than a predetermined value. If the water distribution pressure is equal to or higher than the stop pressure value, exceeds the high water distribution stop pressure value, or if this state continues for a predetermined time, it is determined that the water distribution pressure is high (high water distribution pressure state). The high water distribution pressure stop pressure value is determined based on the target pressure Pdv. For example, in the present embodiment, the target pressure Pdv is the high water distribution pressure stop pressure value. That is, the control unit 18b determines whether the pump suction pressure Ps1 exceeds the target pressure Pdv that fluctuates according to the water supply amount, and the state in which the pump suction pressure Ps1 exceeds the target pressure Pdv continues for a certain time t2 or longer. In this case, it is determined that the water distribution pressure is high, and the pump is stopped. The fixed time t2 is set to, for example, about 3 seconds.

Further, the control unit 18b determines whether or not the discharge pressure Pd satisfies a predetermined starting condition while the pump 23 is stopped. As an example, the control unit 18b determines that the starting condition is satisfied and causes the pump 23 to operate when, for example, the discharge pressure Pd drops below a predetermined starting pressure set lower than the second target pressure Pd2, which is the minimum target pressure. resume.

Furthermore, the controller 18b stops the pump 23 when the pump suction pressure Ps1 drops below a predetermined value while the pump 23 is in operation. For example, the control unit 18b determines whether the pump suction pressure Ps1 is equal to or lower than the first reference value Pt1, and determines that the suction pressure has decreased when the pump suction pressure Ps1 has decreased to the first reference value Pt1 or lower. , the pump 23 is stopped.

The first reference value Pt1 is a threshold value stored in the storage device 18a, and is set to a pressure such as a positive pressure that can prevent air bubbles from being generated on the suction side of the pump due to cavitation. As an example, in this embodiment, the first reference value Pt1 is set to 0.01 MPa. The pressure of the water pipe is 0.01 MPa plus the pressure loss of the backflow prevention device, strainer, etc. at the water supply amount at this time.

Further, the control unit 18b restarts when the pump suction pressure Ps1 rises from the first reference value Pt1 or less to a predetermined value or more. Specifically, while the pump 23 is stopped, the control unit 18b determines whether or not the pump suction pressure Ps1 is equal to or higher than the second reference value Pt2. The controller 18b restarts the operation of the pump 23 when the pump suction pressure Ps1 rises to or above the second reference value Pt2.

The second reference value Pt2 is, for example, a threshold value set higher than the first reference value Pt1 and stored in the storage device 18a. As an example, in this embodiment, the second reference value Pt2 is set to 0.04 MPa, for example.

The control unit 18b repeats these processes until an instruction to end the operation of the pump is given, and when the instruction to end the operation is given, the operation is finished.

According to the pressurized water supply apparatus 1 configured as described above, by controlling the stoppage of the pump based on the pump suction pressure on the secondary side of the backflow prevention device and the target pressure, the suction pressure on the primary side of the backflow prevention device Hunting phenomenon can be suppressed compared to the case of detecting pressure, and stable control becomes possible.

In the pressurized water supply device 1, when the pump 23 is in operation, the pump suction pressure Ps1 exceeds a target pressure that varies according to the amount of water supply (in the case of constant estimated terminal pressure control, it changes in conjunction with the amount of water supply). , the pump 23 is stopped even if the flow rate detected by the flow rate sensor 17 exceeds the stop flow rate when it continues for a certain period of time. That is, the pump suction pressure on the secondary side of the backflow prevention device and the target pressure are directly compared. For this reason, even if the total value of the pressure loss added by pressure-reducing valve-type backflow prevention devices and strainers of various diameters fluctuates in a complex manner due to fluctuations in the amount of water supplied, the Then, the pump 23 can be automatically stopped. Therefore, after the pump 23 stops, the water stored in the accumulator 14 does not flow out and the discharge pressure does not drop to the starting pressure set lower than the second target pressure Pd2, and the pump 23 restarts. phenomenon can be prevented. Therefore, the hunting phenomenon can be effectively prevented, and stable automatic control can be performed. Therefore, since there is no need to consider the pressure loss of a backflow prevention device, strainer, etc., compared to the method of setting a margin that considers these pressure losses, it is easier to set the optimal settings without wasting power. is possible.

In addition, in the pressure increasing water supply device 1, the suction pressure Ps1 of the pump 23 of the pressure increasing water supply device 1 became equal to or less than a predetermined first reference value Pt1 (eg, 0.01 MPa) during operation of the pump 23. In this case, the pump 23 is automatically stopped, and while the pump 23 is stopped, the suction pressure Ps1 of the pump 23 recovers to a second reference value Pt2 (eg, 0.04 MPa) set higher than the first reference value Pt1. , the pump 23 is operable. As a result, even if the suction pressure of the booster water supply device 1, that is, the pressure of the water pipe 10 exceeds a predetermined value (eg, 0.07 MPa), the pump suction pressure is a positive pressure, a predetermined first reference value Pt1 (eg, : 0.01 MPa), the pump 23 automatically stops. Therefore, it is possible to prevent the suction pressure of the pump 23 from becoming a negative pressure and cavitation to occur, thereby preventing pumping.

In addition, in the pressure increasing water supply device 1 according to the above embodiment, when the suction pressure Ps1 fluctuates rapidly, by fixing the target pressure, stable It becomes possible to drive. That is, due to a rapid change in the pump suction pressure Ps1, even though the water supply flow rate Q has not changed, an excessive decrease in the target pressure as indicated by the solid line arrow in FIG. 4 or an unnecessary increase in the target pressure Useless power consumption can be prevented. For example, due to a sudden rise in suction pressure, the discharge pressure increases, and when the discharge pressure is reduced to the target pressure, the pressure reduction cannot keep up with it, and the water supply flow rate increases, the target pressure increases, and the target pressure becomes insufficient. The discharge pressure drops due to a sudden drop in suction pressure, and the discharge pressure is increased to the target pressure. By fixing the target pressure in accordance with the amount of variation, it is possible to prevent the problem that the pressure drops and the end pressure drops due to the shortage of the target pressure.

Furthermore, the pressure increasing water supply device 1 is provided with a flow rate detection unit having an output characteristic proportional to the flow rate, measures the operating flow rate of the water supply device, and performs estimated end pressure constant control, so that the suction pressure fluctuates per time When the width is small, stable automatic control is possible compared to the method of determining the target pressure using the output frequency to the pump as a variable. That is, for example, when the suction pressure rises and the discharge pressure increases, control is possible to reduce the discharge pressure to the target pressure and keep the water supply flow rate unchanged. Alternatively, when the suction pressure drops and the discharge pressure drops, control is possible to increase the discharge pressure to the target pressure so that the water supply flow rate does not fluctuate.

As described above, according to the pressure increasing water supply device 1, the suction pressure on the primary side of the backflow prevention device is detected by controlling the stoppage of the pump based on the pump suction pressure on the secondary side of the backflow prevention device. Compared to , the hunting phenomenon can be suppressed, and stable control becomes possible.

It should be noted that the present invention is not limited to the examples of the above embodiments. Various set values and control reference values can be appropriately changed according to the configuration of the pump device and various conditions. For example, in the above-described embodiment, the high water distribution pressure stop pressure value is set to the target pressure that is the reference for the feedback control of the discharge pressure, but the present invention is not limited to this. For example, the high distribution pressure stop pressure value may be set to a value that is higher or lower than the target pressure, corresponding to the target pressure. (ratio k is less than 1.0 or more than 1.0) may be set as the high water distribution pressure stop pressure value. Also in this case, since there is no need to consider the pressure loss of the backflow prevention device, strainer, etc., the same effect as the above embodiment can be obtained.
Also, the first reference value Pt1, the second reference value Pt2, and the durations t1 and t2 are not limited to the above embodiment, and can be changed as appropriate. For example, in the case of periodic detection, if the detection result satisfies the condition for a plurality of consecutive times, it may be determined that the detection continues for a predetermined period of time. For example, when the ejection pressure is detected every one second, it may be determined that the condition continues when the condition is satisfied two or more times or three or more times in succession.

In the above embodiment, the pump 23 is feedback-controlled by the estimated terminal pressure constant control. However, the present invention is not limited to this. good.

Further, as a pressurized water supply apparatus 1A according to another embodiment, as shown in FIG. A pressure sensor 60 may be further provided on the primary side as a pressure detection section for detecting the pressure on the primary side of the backflow prevention device 13 .

It should be noted that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying constituent elements without departing from the gist of the present invention at the implementation stage. Furthermore, the present invention can be realized even if some of the constituent requirements of the above embodiments are omitted.
The invention described in the original claims of the present application is appended below.
(1)
a pump;
a backflow prevention device arranged on the primary side of the pump and connected to a water pipe;
a pump suction pressure detection unit disposed between the backflow prevention device and the pump for detecting a pump suction pressure on the suction side of the pump;
a discharge pressure detection unit arranged on the secondary side of the pump for detecting the discharge pressure on the discharge side of the pump;
The operation of the pump is controlled based on the discharge pressure and target pressure on the secondary side of the pump, and the pump suction pressure on the primary side of the pump, which is the secondary side of the backflow prevention device, during operation of the pump. and a control unit that stops the pump when a high water distribution pressure state is reached based on.
(2)
The control unit determines that the pump suction pressure is in the high water distribution pressure state when the pump suction pressure is equal to or higher than a predetermined high water distribution pressure stop pressure value determined based on the target pressure or exceeds the high water distribution pressure stop pressure value during operation of the pump. Stop the pump as
The booster water supply apparatus according to (1), wherein the pump is started when the discharge pressure drops to a starting pressure set lower than the target pressure while the pump is stopped.
(3)
When the pump suction pressure exceeds a predetermined high water distribution pressure stop pressure value determined based on the target pressure or exceeds the high water distribution pressure stop pressure value during operation of the pump, the control unit controls the operation of the pump for a predetermined time. , The booster water supply system according to (1), wherein the pump is stopped assuming that the water distribution pressure is high.
(4)
The control unit stops the pump when the pump suction pressure drops below a first reference value during operation of the pump, and stops the pump suction pressure when the pump suction pressure is lower than the first reference value while the pump is stopped. The pressurized water supply system according to any one of (1) to (3), wherein the pump is restarted when the second reference value or higher is reached.
(5)
The control unit increases the output frequency or flow rate from the second target pressure at the stop flow rate to the first target pressure at the rated flow rate in the flow range from the stop flow rate to the rated flow rate in the estimated terminal pressure constant control method. Controlling the output of the pump based on the target pressure that fluctuates with
The booster water supply system according to any one of (1) to (4), wherein the target pressure is fixed for a predetermined time when the amount of variation in the pump suction pressure is equal to or greater than a predetermined variation reference value.
(6)
With a plurality of pumps,
A suction pipe connected to the primary side of the backflow prevention device, a suction connecting pipe having a flow path leading to the pump suction ports of the plurality of pumps on the secondary side of the backflow prevention device, and a pump discharge port of the pump. a discharge connecting pipe having an individual discharge flow channel communicating with a secondary side, a bypass flow channel communicating from the individual discharge flow channel to the suction connecting pipe, and a discharge port communicating with a water supply destination; A pipe having a check valve on the discharge side;
The pressurized water supply apparatus according to any one of (1) to (5), further comprising a flow rate detection unit arranged in the individual discharge flow path and outputting a signal proportional to the amount of water supply.
(7)
The booster water supply system according to any one of (1) to (6), further comprising a pressure detection unit disposed on the primary side of the backflow prevention device and detecting pressure on the suction side of the backflow prevention device.
(8)
a pump suction pressure between a backflow prevention device arranged on the primary side of a pump and said pump;
detecting the discharge pressure on the secondary side of the pump;
A booster water supply system that controls the output of the pump based on a predetermined target pressure and the discharge pressure, and stops the pump when the distribution pressure of the pump becomes high based on the pump suction pressure during operation of the pump. control method.
(9)
(8), wherein when the pump suction pressure is equal to or higher than a predetermined high water distribution pressure stop pressure value determined based on the target pressure or exceeds a high water distribution pressure stop pressure value, the pump is stopped as the high water distribution pressure. control method of booster water supply equipment.
(10)
When the pump suction pressure becomes equal to or less than the first reference value during operation of the pump, the pump is stopped. The method for controlling a booster water supply apparatus according to (8) or (9), wherein the pump is operated when the second reference value higher than the reference value is reached.
(11)
In the estimated end pressure constant control method, in the flow rate range from the stop flow rate to the rated flow rate, it fluctuates from the second target pressure at the stop flow rate to the first target pressure at the rated flow rate as the output frequency or flow rate increases. Controlling the output of the pump based on the target pressure,
The control method for a booster water supply system according to any one of (8) to (10), wherein the target pressure is fixed for a predetermined time when the amount of fluctuation of the pump suction pressure is equal to or greater than a predetermined fluctuation reference value.

DESCRIPTION OF SYMBOLS 1... Increased pressure water supply apparatus 10... Water pipe 11... Pump apparatus 12... Piping 12a... Suction port 12b... Discharge port 13... Backflow preventive device 13a... First check valve 13b... Second check valve 13c retainer 14 accumulator 15 first pressure sensor 16 second pressure sensor 17 flow rate sensor 18 electrical unit 18a storage device 18b control unit 18c inverter , 19... Pump cover, 21... Motor, 22... Impeller, 23... Pump, 23a... Pump suction port, 23b... Pump discharge port, 31... Suction pipe, 32... Suction connecting pipe, 33... Ball valve part, 34... Individual Discharge pipe 35 Discharge connecting pipe 36 Bypass connecting pipe 37 Strainer 51, 52 Check valve.

Claims (4)

a pump;
a backflow prevention device arranged on the primary side of the pump and connected to a water pipe;
a pump suction pressure detection unit disposed between the backflow prevention device and the pump for detecting a pump suction pressure on the suction side of the pump;
a discharge pressure detection unit arranged on the secondary side of the pump for detecting the discharge pressure on the discharge side of the pump;
a flow rate detection unit arranged in the discharge channel and outputting a signal proportional to the amount of water supply;
In the estimated end pressure constant control method, in the flow rate range from the stop flow rate to the rated flow rate, the target pressure fluctuates as the flow rate increases, from the second target pressure at the stop flow rate to the first target pressure at the rated flow rate. The output of the pump is controlled based on the above, and if the pump suction pressure exceeds the target pressure that fluctuates according to the amount of water supply during operation of the pump and continues for a certain period of time, it is determined that the water distribution pressure is high. , a control unit that stops the pump even if the flow rate detected by the flow rate detection unit exceeds the stop flow rate;
A booster water supply device. The control unit stops the pump when the pump suction pressure drops below a first reference value capable of preventing air bubbles from being generated on the suction side of the pump due to cavitation during operation of the pump. 2. The booster water supply system according to claim 1, wherein the pump is restarted when the suction pressure of the pump becomes equal to or higher than a predetermined second reference value higher than the first reference value while the pump is stopped. a pump;
a backflow prevention device arranged on the primary side of the pump and connected to a water pipe;
a pump suction pressure detection unit disposed between the backflow prevention device and the pump for detecting a pump suction pressure on the suction side of the pump;
a discharge pressure detection unit arranged on the secondary side of the pump for detecting the discharge pressure on the discharge side of the pump;
A pressurized water supply apparatus comprising a flow rate detection unit arranged in a discharge flow path and outputting a signal proportional to the amount of water supply,
In the estimated end pressure constant control method, in the flow rate range from the stop flow rate to the rated flow rate, the target pressure fluctuates as the flow rate increases, from the second target pressure at the stop flow rate to the first target pressure at the rated flow rate. The output of the pump is controlled based on the above, and if the pump suction pressure exceeds the target pressure that fluctuates according to the amount of water supply during operation of the pump and continues for a certain period of time, it is determined that the water distribution pressure is high. , stopping the pump even if the flow rate detected by the flow rate detection unit exceeds the stop flow rate;
A control method for a booster water supply system. stopping the pump when the suction pressure of the pump drops below a first reference value capable of preventing air bubbles from being generated on the suction side of the pump due to cavitation while the pump is in operation; 4. The method of controlling a booster water supply system according to claim 3, wherein the pump is restarted when the suction pressure reaches or exceeds a predetermined second reference value higher than the first reference value.

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