JP3043514B2 - Water supply pressurization device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed water pressurizing device directly connected to a water distribution pipe to increase the feed water pressure.

[0002]

2. Description of the Related Art Generally, the hydraulic pressure of a distribution pipe of a public water supply is 1.
It is maintained at about 5 kg / cm2 to 2.0 kg / cm2. However, with this, there is insufficient pressure to supply water to the terminal water supply equipment provided in middle- and high-rise buildings of 3 stories or more.
In such a case, as shown in FIG.
Is temporarily stored in the water receiving tank 2, the pressure is increased by the pressurizing pump 3, and the water is supplied to the terminal water supply device 4. Further, as shown in FIG. 1B, water from the water distribution pipe 1 is received by the water receiving tank 2, and the water is pumped up by the water pump 6 into the elevated water tank 5 installed at the top of the building. There is also a method in which water is supplied to each terminal water supply device 4 by natural flow.

[0003] However, in any of the systems, water from the water distribution pipe 1 is once discharged into the water receiving tank 2, so that a water pressure of nearly 2.0 kg / cm2 cannot be effectively used. However, there is a problem that the amount of power consumption is increased due to a large waste of energy.

[0004] Moreover, once water is stored in the water receiving tank, the residual chlorine gradually decreases.
Those exceeding 3 cubic meters are subject to the regulation of the Simple Water Supply Law, and safety and health management is obligated.However, maintenance of water receiving tanks becomes more difficult due to the rise in equipment costs and labor costs due to the recent rise in land prices. I have. In addition, although a small receiving tank is not subject to regulations, in this case, sanitary problems are likely to occur.

Therefore, in recent years, a direct water supply system in which a water supply pressurizing device is directly connected to a water distribution pipe and the water is supplied from the water supply pressurizing device to a terminal water supply device has been studied. The basic structure of this method is to connect a pressure pump and a pressure storage tank to the water distribution pipe in order, connect the pressure storage tank side to the terminal water supply equipment, and provide an outflow pressure sensor that measures the water pressure at the outflow side of the pressure pump. When the water pressure on the outflow side drops below a predetermined value, the pressure pump is operated to increase the pressure.

[0006] In this way, since the water receiving tank can be eliminated, the water pressure on the water distribution pipe side can be effectively used to save power. In addition, since there is no problem of hygiene in the receiving tank, there is a great advantage that sanitary water can always be secured.

[0007]

However, in the above-described configuration, when the pressure on the outflow side is reduced, the pressurizing pump is uniquely operated. For this reason, when the demand for water supply increases greatly, the pressurizing pump is continuously operated to absorb a large amount of water from the water distribution pipe side, and the water pressure of the water distribution pipe connected to this device is reduced. This means that poor flooding and turbid water are likely to occur in the area near the building, which impairs fairness of water supply.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a direct water supply system that is directly connected to a water distribution pipe while preventing water supply pressure from being exerted on water distribution pipes from being adversely affected, thereby preventing loss of water supply fairness. It is an object to provide a pressure device.

[0009]

The feed water pressurizing apparatus of the present invention is provided so as to be connected to a pressurizing pump connected to a water distribution pipe and a water supply pipe from the outlet side of the pressurizing pump to the terminal water supply apparatus. A pressure storage tank, a check valve provided between the pressure storage tank and the water distribution pipe, an inflow pressure sensor for measuring the water pressure on the water distribution pipe side of the pressure pump, and a water pressure on the discharge side of the pressure pump. Outflow pressure sensor for measuring the pressure, a pump drive circuit for driving the pressurizing pump, and control means for controlling the pump drive circuit, the control means,
When the water pressure measured by the inflow pressure sensor exceeds a predetermined value, the outflow pressure priority control for controlling the pump drive circuit is performed so that the outflow pressure measured by the outflow pressure sensor becomes constant. When the water pressure is equal to or lower than a predetermined value, the inflow pressure priority control for controlling the pump drive circuit is performed such that the water pressure on the water distribution pipe side does not fall below a predetermined lower limit.

[0010]

When the water pressure on the water distribution pipe side is sufficient, the water pressure measured by the inflow pressure sensor exceeds a predetermined value. Then, “outflow pressure priority control” is executed, and the pressurizing pump is operated so that the outflow pressure measured by the outflow pressure sensor becomes constant. As a result, a sufficient outflow pressure is always ensured, so that sufficient water can be supplied to the middle and high-rise buildings, and power consumption can be reduced by effectively utilizing the water pressure on the water distribution pipe side to increase the pressure.

When the pressurizing pump is stopped because the outflow pressure is sufficiently increased, a check valve is provided between the water distribution pipe and the pressure storage tank. Therefore, the water in the pressure storage tank does not escape to the water distribution pipe side to reduce the outflow pressure, and the pressurizing pump is not operated unnecessarily.

On the other hand, when the water pressure on the water distribution pipe side is insufficient, the water pressure measured by the inflow pressure sensor falls below a predetermined value. The operation is performed within a range where the water pressure on the water distribution pipe side does not fall below a predetermined lower limit. As a result, in this case, the water supply pressure to the terminal water supply equipment may be insufficient on the upper floor of the building, etc., but at least the worst case of excessively reducing the water pressure on the water distribution pipe side must be avoided. Can be.

[0013]

According to the feed water pressurizing apparatus of the present invention, the following effects can be obtained.

When the water pressure on the water distribution pipe side is lower than a predetermined value,
Since the inflow pressure priority control is performed, even if it is directly connected to the distribution pipe, the water pressure of the distribution pipe will not be excessively reduced, and it is possible to prevent the occurrence of unfair water supply such as poor flooding in the neighboring area. it can. Of course, since the water supply system is a direct water supply system that does not require a water receiving tank, the power consumption can be greatly reduced, so that it is possible to meet the demand for energy saving and to always enable sanitary water supply.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. Figure 1 shows a distribution pipe 1 for public water supply.
1 to the feed water pressurizing device 2 of the present invention
0 is directly connected, and water is supplied to the terminal water supply device 15 installed on each floor in the middle and high-rise building 14 from the water supply pipe 13 through the outflow side water supply pipe 13.

In the feed water pressurizing device 20, a pipe between the inflow side water supply pipe 12 and the outflow side water supply pipe 13 is provided with a double check valve 2
1, a pressurizing pump 22 and a flow rate switch 23 are connected in order, and a bypass having a check valve 24 between the suction side and the outflow side of the pressurizing pump 22 for preventing backflow from the outflow side A tube 25 is provided. Pressurizing pump 2
A pressure storage tank 26 is provided in a pipe line on the outflow side of 2 and connected to the outflow side water supply pipe 13 so that water discharged from the pressurizing pump 22 is stored in a predetermined pressure state so that the water supply pressure can be smoothed. I have to.

On the inflow side of the pressurizing pump 22, an inflow pressure sensor 27 is located upstream of the double check valve 21.
Is provided to measure the water pressure (hereinafter referred to as “inflow pressure Ps”) on the water distribution pipe 11 side of the pressurizing pump 22. On the other hand, an outflow pressure sensor 28 is provided on the outflow side of the pressurizing pump 22, and measures the water pressure on the outflow side (hereinafter referred to as "outflow pressure Pd").

The pressurizing pump 22 is operated by a pump driving circuit 29. The pump drive circuit 29 includes a well-known inverter that outputs a variable frequency / variable voltage (VVVF), and can operate the pressurizing pump 22 at a desired speed. According to the calculation, the outflow pressure Pd is increased in proportion to the square of the output frequency of the inverter device.

On the other hand, the control means 30 for controlling the pump drive circuit 29 is provided with a microcomputer, and the software structure directly related to the present invention is as shown in FIGS.

Next, the operation of the present embodiment will be described together with the control mode of the control means 30. Now, it is assumed that the feed water pressurizing device 20 is installed with piping as shown in FIG. 1 and power is supplied to the device. Then, as shown in FIG.
First, the entire control means 30 is initialized and various set reference data are read (step 10).
0). Each of these reference data is input in advance by an administrator of the apparatus.

Here, the meaning of various reference data used in this embodiment will be described together with two variables. Ps: inflow pressure = follows the hydraulic pressure (variable) measured by the inflow pressure sensor 27 with a fixed relation to the dynamic water pressure of the water distribution pipe. PSH: Upper limit start-up inflow pressure = upper limit of inflow pressure which is a condition for starting the pressurizing pump 22 When there is an inflow pressure equal to or more than this value, the pressurizing pump 22 is not started (constant). PSL: lower limit starting inflow pressure = lower limit inflow pressure as a condition for starting the pressurizing pump 22 When the inflow pressure is equal to or lower than this value,
The pressurizing pump 22 is not started. It also serves as a reference value for selecting “outflow pressure priority control” and “inflow pressure priority control” to be described later. PSA: target lower limit inflow pressure = target lower limit of inflow pressure when “inflow pressure priority control” is performed. The inflow pressure is controlled so as not to drop below this value. Pd: outflow pressure = water pressure (variable) measured by the outflow pressure sensor 28 PDS: start-up outflow pressure = outflow pressure that is a condition for starting the pressurizing pump 22. When the outflow pressure falls below this value, pressure increase by the pressure pump 22 is started. PDA: Target outflow pressure = Target value of water supply pressure to terminal water supply equipment. In the "outflow pressure priority control", the pressurizing pump 22 is controlled so that the feed water pressure becomes this value. (1) Startup of the pressure pump 22 Now, following the initial processing of step 100, step 10
1 is executed, and first, a magnitude relationship between the inflow pressure Ps and the upper limit startup inflow pressure PSH is determined. Here, the process shifts to the step on the pump start side on condition that the inflow pressure Ps is lower than the upper limit startup inflow pressure PSH. If the inflow pressure Ps is equal to or higher than the upper limit startup inflow pressure PSH, the pump is not started (step 102). The reason is that when the inflow pressure Ps exceeds the upper limit startup inflow pressure PSH, water can be supplied by the inflow pressure PS itself, so that unnecessary pressurization is avoided to save energy.

Next, the routine proceeds to step 103, where it is determined whether or not the pump is operating. Immediately after the power is turned on or when the pressure pump 22 is stopped, the determination result is “NO”.
Then, the process proceeds to step 104, where a magnitude relationship between the inflow pressure Ps and the lower limit startup inflow pressure PSL is determined. Here, the process proceeds to the step on the pump starting side on condition that the inflow pressure Ps is equal to or higher than the lower limit starting inflow pressure PSL. If the inflow pressure Ps is less than the lower limit starting inflow pressure PSL, the pump is not started (step 102). . This is to prevent the operation of the pressurizing pump 22 from further lowering the water pressure on the water distribution pipe 11 when the inflow pressure Ps is such a low pressure.

However, if the inflow pressure Ps is higher than the lower limit startup inflow pressure PSL, the process proceeds to step 105, where the water pressure on the outflow side (outflow pressure Pd) of the pressurizing pump 22 is compared with the startup outflow pressure PDS. Is done. Immediately after the installation of the present apparatus, the outflow pressure Pd is substantially equal to the inflow pressure Ps, which is generally lower than the startup / outflow pressure PDS, so that the pressurizing pump 22 is started by the pump drive circuit 29 (step 106).
The pump is started by V / F constant control in which the output frequency and the output voltage of the inverter device of the pump drive circuit 29 are gradually increased while maintaining the output voltage at a predetermined ratio, whereby the outflow pressure Pd is reduced to the time t0 in FIG. As shown below, the inflow pressure P
It rises rapidly away from s.

After the start, at step 107 the inflow pressure P
The magnitude relationship between s and the lower limit startup inflow pressure PSL is determined. If the inflow pressure Ps is sufficient and exceeds the lower limit startup inflow pressure PSL, an "outflow pressure priority control" routine is executed (step 2).
00), if not, the "inflow pressure priority control" routine is executed (step 300).

(2) Outlet Pressure Priority Control First, the case where the inflow pressure Ps exceeds the lower limit starting inflow pressure PSL and the "outlet pressure priority control" is executed will be described.

The contents of this control are as shown in FIG. 3. First, a pressure deviation ΔPd of the outflow pressure Pd from the target outflow pressure PDA is determined (step 201), and its sign is determined (step 202).

When the pressure deviation ΔPd is positive (outflow pressure Pd is lower than the target outflow pressure PDA), the deviation ΔPd
The pump is accelerated at a frequency and a voltage corresponding to (the higher the deviation ΔPd, the higher the frequency and the higher the rotation speed of the pump). When the execution of step 203 is completed, the process returns to the main routine of FIG. When the pressure deviation ΔPd is 0 or negative (outflow pressure Pd is equal to or higher than the target outflow pressure PDA), the process proceeds to step 204.

When the outflow pressure Pd is equal to the target outflow pressure PDA and the pressure deviation .DELTA.Pd is 0, "YES" is obtained in step 204, so that the output frequency and voltage of the inverter device of the pump drive circuit 29 are at that time. The pressure is maintained and the pressure pump 22 is operated at a constant speed (step 20).
5) After that, the process returns to the main routine.

On the other hand, if the outflow pressure Pd is higher than the target outflow pressure PDA, the answer is "NO" also in step 204. Therefore, the frequency and voltage of the inverter device are reduced in accordance with the pressure deviation ΔPd, thereby increasing the pressure. The rotational speed of the pump 22 is reduced (step 206), and the process returns to the main routine. If the rotation speed of the pressure pump 22 is reduced,
The outflow pressure Pd will decrease.

After the return, "YES" is made in step 107 of the main routine, and the flow returns to steps 201 and 202 of the "outflow pressure priority control" routine again. Therefore, at this stage, if the outflow pressure Pd decreases to the target outflow pressure PDA and the pressure deviation ΔPd becomes 0, the operation shifts to the constant speed operation of the pump (step 205), and the outflow pressure Pd is still higher than the target outflow pressure PDA. If it is also higher, the process returns to step 206 to execute the deceleration operation of the pump.

When the pump control that repeats such a loop is performed, the outflow pressure Pd is always kept equal to the target outflow pressure PDA as shown in FIG. This is the end water supply equipment 1
In 5, the water can be used with a sufficient water pressure.

When returning to the main routine of FIG. 2, the state of the flow switch 23 is referred to (step 10).
8) If the flow rate is, for example, 5 liters per minute or less, the operation of the pressurizing pump 22 is stopped. If the flow rate exceeds 5 liters per minute, the flow returns to step 101 and loops.
In this case, after the pressurizing pump 22 is activated once, the result of step 103 becomes “YES”.
The "outflow pressure priority control" is continued by looping while skipping the determination at 105.

In this state, even when the water demand in the terminal water supply device 15 decreases and the pressurizing pump 22 is stopped, for example, the check valve 21 is provided in the outflow side water supply pipe 13 on the pressurizing pump 22 side. As a result, the pressure on the pressure storage tank 26 side is not released to the water distribution pipe 11 side.
After the time t1, the outflow pressure Pd maintains the target outflow pressure PDA even after the pressurizing pump 22 is stopped. Therefore, the pressure does not gradually escape after the stop of the pressurizing pump 22, and the pump is not repeatedly operated, which meets the demand for energy saving.

Although the occurrence of the water hammer phenomenon is feared by stopping the pressurizing pump 22, the steep water pressure fluctuation is reduced because the outlet water supply pipe 13 is connected to the pressure storage tank 26. Since it is absorbed by the pressure storage tank 26, there is no possibility of damaging each device.

When the pressurizing pump 22 is stopped, "N" is selected in step 103 in the flowchart of FIG.
O ”, steps 104, 105, 102, 1
A loop passing through 01 and 103 in order is executed, and the pressurizing pump 22 is in a standby state. Even if the water demand increases in this state, the water stored in the pressure storage tank 26 is gradually supplied, and the pressurizing pump 22 does not immediately enter the operating state. However, since the outflow pressure Pd gradually decreases in accordance with the outflow of water (see time t2 in FIG. 5), when the outflow pressure Pd falls below the starting outflow pressure PDS (time t3 in FIG. 5), step 106 is performed. Is "YES", and the pressurizing pump 22 is started. This makes the outflow pressure Pd
Rises again and is maintained at the target outflow pressure PDA (refer to FIG. 5 after time t4).

(3) Inlet Pressure Priority Control Now, it is assumed that the water pressure on the water distribution pipe 11 has dropped significantly for some reason when the "outlet pressure priority control" is being executed as described above. Then, when the inflow pressure Ps falls below the lower limit startup inflow pressure PSL, step 10 in FIG.
Since the determination result of step 7 is “NO”, the “inflow pressure priority control” routine shown in FIG. 4 is executed.

The basic control principle of the "inflow pressure priority control" is to operate the pump so that the pressure deviation ΔPd on the outflow side becomes zero if the pressure deviation ΔPs on the inflow side has a margin. Since there is no margin for the pressure deviation ΔPs, if the inflow pressure Ps falls below the target lower limit inflow pressure PSA when the pump is operated, the operation of the pump is performed with priority given to maintaining the inflow pressure Ps at the target lower limit inflow pressure PSA. There is a place to refrain from.

Therefore, here, both the pressure deviation ΔPs of the inflow pressure Ps from the target lower limit inflow pressure PSA and the pressure deviation ΔPd of the outflow pressure Pd from the target outflow pressure PDA are taken into consideration. The relationship with the operation mode of the pressure pump 22 is as shown in the following table. Referring to the flowchart of FIG. 4, first, a pressure deviation ΔP of the inflow pressure Ps from the target lower limit inflow pressure PSA will be described.
s and the pressure deviation ΔP of the outlet pressure Pd from the target outlet pressure PDA
are calculated (step 301), and the process proceeds to the determination step of step 302. Here, the following cases are separately described.

When the inflow pressure Ps is higher than the target lower limit inflow pressure PSA and the outflow pressure Pd is lower than the target outflow pressure PDA. This state is shown as a state before time t5 in FIG. This means that there is still room, and the outflow pressure Pd is less than the target value.

Therefore, in this case, both pressure deviations ΔPs,
Since ΔPd is both positive and the result of the determination in step 302 is “YES”, the flow shifts to step 303, where the pressure pump 2
2 is accelerated for a certain period of time and returns to the main routine of FIG. 3 (the greater the deviation, the higher the frequency and the higher the pump speed). This acceleration operation causes the outflow pressure Pd to increase and the inflow pressure Ps to decrease. After returning to the main routine, “NO” in step 107
Then, the routine immediately returns to the "inflow pressure priority control" routine in FIG. 4, and this routine is repeated.

Here, at the time t in FIG.
5 As shown later, when the outflow pressure Pd reaches the target outflow pressure PDA first, ΔPs> 0, ΔPd = 0, so “NO” is obtained in steps 302, 304, and 305.
For this reason, the pump drive circuit 29 fixes the output frequency and voltage of the inverter device to the values at that time, and
The second constant speed operation is executed (step 306). Thereby, as shown between time t5 and time t6 in FIG.
The state in which the inflow pressure Ps is higher than the target lower limit inflow pressure PSA and the outflow pressure Pd is equal to the target outflow pressure PDA is maintained, and the water pressure (inflow pressure Ps) on the water distribution pipe 11 side is excessively reduced. Thus, a sufficient amount of water to be supplied to the terminal water supply device 15 is ensured.

On the other hand, as shown after time t7 in FIG.
Contrary to the case described above, the pressure deviation ΔPd of the outflow pressure Pd is zero.
If the pressure deviation ΔPs of the inflow pressure Ps becomes 0 before the pressure becomes 0, ΔPs = 0 and ΔPd> 0. Is performed at a constant speed. As a result, the outflow pressure Pd is lower than the target outflow pressure PDA, but the inflow pressure Ps is maintained to be equal to the target lower limit inflow pressure PSA (see FIG. 6 from time t7 to time t8). It does not fall below the lower limit inflow pressure PSA. Therefore, it is possible to reliably prevent a large amount of water from being absorbed from the water distribution pipe 11 by the operation of the pressurizing pump 22. It is possible to prevent the failure of water supply and the occurrence of muddy water, thereby preventing the fairness of water supply from being impaired.

In this situation, the water supply pressure to the terminal water supply device 15 cannot be sufficiently secured. However, this is because the water pressure on the water distribution pipe 11 side is originally excessively low.
Unavoidable. Rather, as a pressurized water supply system directly connected to public water supply, priority should be given to ensuring fairness in water supply.

When the inflow pressure Ps is lower than the target lower limit inflow pressure PSA This situation occurs, for example, when the pressure pump 22 is operating at a constant speed to maintain the inflow pressure Ps constant as described above (step 306). If a loop that repeats is executed)
This occurs when the water pressure on the water distribution pipe 11 side further decreases.

In this case, since ΔPs <0, “NO” is determined in step 302 and “YES” is determined in step 304, and the process proceeds to step 307, where the frequency and voltage of the inverter are reduced by ΔPs for a few seconds. The deceleration operation of the pressurizing pump 22 that is reduced according to the value is executed. As a result, the amount of water supplied from the water distribution pipe 11 decreases, and the inflow pressure Ps should recover in the upward direction. Therefore, thereafter, the pressure deviation ΔPs is calculated again (step 308),
It is determined whether or not the inflow pressure Ps has recovered to become equal to the target lower limit inflow pressure PSA (step 309). If it is determined that ΔPs ≧ 0, it is determined in step 30
Then, the routine goes to 6 to execute the constant speed operation of the pressure pump 22.

However, if the inflow pressure Ps does not recover even after the above-described deceleration operation, ΔP
Since s <0 and the result of the determination in step 309 is "YES", the operation proceeds to step 310 to stop the operation of the pressure pump 22. Therefore, when the water pressure on the water distribution pipe 11 becomes excessively low such that the inflow pressure Ps does not recover even if the pressure pump 22 is decelerated, the operation of the pressure pump 22 is stopped, and the water absorption from the water distribution pipe 11 is stopped. Is interrupted. As a result, although it is difficult to supply sufficient water to the terminal water supply device 15 in the building, it is possible to reliably prevent poor water discharge and generation of turbid water near the building, thereby impairing the fairness of water supply. It will not be.

In the case where the outflow pressure Pd is higher than the target outflow pressure PDA Such a situation occurs, for example, when the pressurizing pump 22 is operating at a constant speed in order to maintain the inflow pressure Ps constant (a loop in which step 306 is repeated). Occurs when the water pressure on the water distribution pipe 11 side rises and the outflow pressure Pd rises.

In this case, since the pressure deviation ΔPd becomes negative, “YES” is determined in step 305, and step 31 is performed.
Then, the pressure pump 22 is decelerated in accordance with ΔPd. As a result, the pressure applied by the pressurizing pump 22 decreases, so that the pressure deviation ΔPd should decrease. Then, thereafter, the pressure deviation ΔPd is calculated again (step 312), and it is determined whether or not the outflow pressure Pd has decreased to become equal to the target outflow pressure PDA (step 313).
When it is determined that the pressure has decreased to ΔPd = 0,
The process proceeds to step 306 to execute the constant speed operation of the pressure pump 22.

As described above, according to the present embodiment, the water distribution pipe 11
If the water pressure on the side cannot be sufficiently ensured, the pressure of the pressurizing pump
2 is driven. Therefore, the water pressure on the water distribution pipe 11 side to which the device is connected is not excessively reduced, and it is possible to prevent poor water discharge and the generation of turbid water in the neighborhood of the building, and to guarantee fair supply of water. Can be.

Of course, since the water supply system is a direct connection water supply system that does not require a water receiving tank, the water pressure on the water distribution pipe 11 side can be effectively used to greatly reduce the power consumption and meet the demand for energy saving. Moreover, since there is no water receiving tank, it is possible to always provide sanitary water supply.

Further, in this embodiment, in particular, in the pressure pump 2
2 is provided with a bypass pipe 25 that bypasses 2.
When the pressurizing pump 22 is stopped to obtain a sufficient inflow pressure Ps, water from the water distribution pipe 11 flows into the outflow water supply pipe 13 through the bypass pipe 25 having a small flow resistance. I do. Therefore, the utilization rate of the water pressure on the water distribution pipe 11 side can be increased, and this also contributes to energy saving.

The present invention is not limited to the embodiment described above and shown in the drawings. For example, a configuration may be employed in which a plurality of pressurizing pumps are operated in parallel. In addition, in the above-described embodiment, the inflow pressure sensor 27 is provided in the inflow side water supply pipe 12. However, since it is sufficient that the water pressure on the water distribution pipe side can be measured, the inflow pressure sensor 27 may be provided in a portion closer to the water distribution pipe. Various changes can be made without departing from the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing control by a control unit.

FIG. 3 is a flowchart showing outflow pressure priority control;

FIG. 4 is a flowchart showing inflow pressure priority control;

FIG. 5 is a graph showing a pressure fluctuation when the outflow pressure priority control is performed.

FIG. 6 is a graph showing a pressure fluctuation when the inflow pressure priority control is performed;

FIG. 7 is a graph showing another pressure fluctuation when the inflow pressure priority control is performed.

FIG. 8 is a schematic diagram showing a conventional water supply system for a building.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Water distribution pipe 15 ... Terminal water supply equipment 20 ... Feed water pressurizing device 22 ... Pressurizing pump 25 ... Bypass pipe 26 ... Pressure storage tank 27 ... Inflow pressure sensor 28 ... Outflow pressure sensor 29 ... Pump drive circuit 30 ... Control means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-37911 (JP, A) JP-A-4-330127 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E03B 11/16 E03B 5/00

Claims (1)

(57) [Claims] 1. A pressure pump connected to a water distribution pipe, a pressure storage tank provided from an outlet side of the pressure pump to a water supply pipe to a terminal water supply device, and a pressure storage tank connected to the pressure storage tank. A check valve provided between the pressure pump and a water pipe; an inflow pressure sensor that measures water pressure on a water distribution pipe side of the pressurizing pump; an outflow pressure sensor that measures water pressure on an outlet side of the pressurizing pump; A pump drive circuit for driving the pressurizing pump; and control means for controlling the pump drive circuit. The control means is configured to control the outflow pressure sensor when the water pressure measured by the inflow pressure sensor exceeds a predetermined value. Perform outflow pressure priority control that controls the pump drive circuit so that the measured outflow pressure is constant, and when the water pressure measured by the inflow pressure sensor is equal to or less than a predetermined value,
A feed water pressurizing device that executes inflow pressure priority control for controlling the pump drive circuit so that the water pressure does not fall below a predetermined lower limit.