JP2006161613A - Water-supplying device and starting method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide starting method of a water-supplying device resolving insufficient water supply pressure occurring when flush valves for flushing toilets are used at the same time in a facility such as schools. <P>SOLUTION: In Fig. 9, a plurality of motors 116 for pumps are started at the same frequency (step S1 of starting with equal velocity). Whether or not, a difference F<SB>1</SB>-F<SB>L</SB>between an operational frequency F<SB>1</SB>of n units of motors 116 in operation at the same frequency and a lower limit frequency F<SB>L</SB>corresponding to a lower limit value P<SB>L</SB>of a target pressure is not more than (n-1)/n of a difference between a maximum operation frequency F<SB>max</SB>of the motors 116 and the lower limit frequency F<SB>L</SB>, is determined (step S2 of determining frequency). If it is determined to be not more than (n-1)/n, one unit out of the operating pumps is stopped, then the step S2 of determining frequency is repeated (step of repeating). If it is determined to be more than (n-1)/n, the frequency of the motor 116 of at least one unit of the pumps is fixed, and the frequencies of the motors 116 of the other pumps are changed (step S5 of transferring operation). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water supply apparatus and a starting method thereof, and more particularly to a water supply apparatus installed for supplying water in a facility such as a school and a starting method thereof.

  A direct-connection water supply device has been used in the past to pressurize water from a water main (distribution pipe) directly with a pressure pump (booster pump) without going through a water receiving tank, and supply water to a terminal water supply device (customer). Yes. Such conventional directly connected water supply systems are intended for large buildings such as relatively high-rise apartment buildings and buildings where boosting up with large pumps is indispensable. In order to connect directly to water outage, it is essential to have a backup function with multiple pumps. For this reason, the conventional water supply device is provided with a plurality of pumps, and when an abnormality of a specific pump or an inverter for speed control is detected during operation, the operation is performed on another normal pump or inverter. Switching to continue water supply.

  For example, when flush valves for toilet cleaning are used all at once in a facility such as a school, a large amount of water flows instantaneously, so that water supply by a pump may be insufficient. For this reason, the water supply device is activated while sequentially adding the plurality of pumps described above to cope with a rapid increase in the amount of water used. However, in the conventional method for starting the water supply apparatus, the addition of the pump is not in time for the required amount of water, and a rapid pressure drop occurs due to the additional delay, and it may take time to recover to the normal water supply pressure. Therefore, there is a demand for a method for solving such a shortage of water supply pressure when starting up the water supply device.

  The present invention has been made in view of the above-described problems of the prior art, and is a water supply device that can solve the shortage of water supply pressure that occurs when a flush valve for toilet cleaning in a school or other facility is used at the same time. And a starting method thereof.

  In order to achieve the above object, according to the first aspect of the present invention, the water supply device that can solve the shortage of water supply pressure that occurs when the flush valve for toilet cleaning in a facility such as a school is used at the same time is started. A method is provided. According to this method, the motors of a plurality of pumps are started at the same frequency (uniform speed starting step). The difference between the operating frequency of the n motors operating at the same frequency and the lower limit frequency corresponding to the lower limit value of the target pressure is the difference between the maximum operating frequency of the motor and the lower limit frequency (n−1) / It is determined whether or not n or less (frequency determination step). When it is determined in the frequency determination step that it is (n-1) / n or less, after one of the pumps being operated is stopped, the frequency determination step is repeated (repetition step). When it is determined that the frequency is not less than (n-1) / n in the frequency determination step, the frequency of at least one pump motor is fixed and the frequency of another pump motor is changed (operation transition step). . In this case, it is preferable to repeat the repetitive process until one pump is operated.

  According to the 2nd aspect of this invention, the starting method of the water supply apparatus which can eliminate the shortage of water supply pressure which arises when the flush valve for toilet washing | cleaning in facilities, such as a school, is used simultaneously is provided. According to this method, the water supply device is started when the detected pressure falls below a predetermined starting pressure from a predetermined stop pressure. In the process in which the detected pressure changes from the predetermined stop pressure to the predetermined start pressure, the start pressure at the next start is increased when the detected pressure at a predetermined reference time is lower than a predetermined reference value. . In this case, the predetermined reference value may be an intermediate value between the stop-time pressure and the starting pressure.

  According to the 3rd aspect of this invention, the starting method of the water supply apparatus which can eliminate the shortage of water supply pressure which arises when the flush valve for toilet washing | cleaning in facilities, such as a school, is used simultaneously is provided. According to this method, the water supply device is started when the detected pressure falls below a predetermined starting pressure from a predetermined stop pressure. In the process in which the detected pressure changes from the predetermined stop pressure to the predetermined start pressure, when the time when the pressure of the predetermined reference value is detected is earlier than the predetermined reference time, the start pressure at the next start Is raised. In this case, the predetermined reference value may be an intermediate value between the stop-time pressure and the starting pressure.

  According to the 4th aspect of this invention, the starting method of the water supply apparatus which can eliminate the shortage of water supply pressure which arises when the flush valve for toilet washing | cleaning in facilities, such as a school, is used simultaneously is provided. According to this method, the water supply device is started when the detected pressure falls below a predetermined starting pressure from a predetermined stop pressure. In the process in which the detected pressure changes from the predetermined stop pressure to the predetermined start pressure, when a decrease in the detected pressure in a predetermined period is greater than a predetermined ratio with respect to the difference between the stop pressure and the start pressure The starting pressure at the next start is increased.

  According to the fifth aspect of the present invention, there is provided a water supply apparatus start-up method capable of solving the shortage of water supply pressure that occurs when flush toilet flush valves are used at the same time in facilities such as schools. According to this method, the motors of a plurality of pumps are started at the same frequency (uniform speed starting step). Based on the operating frequency of the plurality of motors operating at the same frequency, it is determined whether a part of the plurality of operating pumps may be stopped (frequency determining step). When it is determined that the frequency determination process may be stopped, a part of the operated pump is stopped (stop process). In this case, when it is determined that it is not necessary to stop in the frequency determination step, it is desirable that the frequency of the motor of at least one pump is fixed (operation transition step).

  According to the 6th aspect of this invention, the water supply apparatus which can eliminate the shortage of water supply pressure which arises when the flush valve for toilet washing | cleaning in facilities, such as a school, is used simultaneously is provided. The water supply apparatus includes a plurality of pumps, a motor that drives the plurality of pumps, and a control unit that controls the speed of the motor so that the pressure on the discharge side of the pump is maintained at a predetermined pressure. Yes. The control unit controls the motor as follows. The motors of a plurality of pumps are started at the same frequency (uniform speed starting process). The difference between the operating frequency of the n motors operating at the same frequency and the lower limit frequency corresponding to the lower limit value of the target pressure is the difference between the maximum operating frequency of the motor and the lower limit frequency (n−1) / It is determined whether or not n or less (frequency determination step). When it is determined in the frequency determination step that it is (n-1) / n or less, after stopping one of the pumps being operated, the frequency determination step is repeated (repetition step). When it is determined that the frequency is not less than (n-1) / n in the frequency determination step, the frequency of at least one pump motor is fixed and the frequency of another pump motor is changed (operation transition step). .

  ADVANTAGE OF THE INVENTION According to the water supply apparatus and its starting method which concern on this invention, the shortage of water supply pressure which arises when using the flush valve for toilet washing | cleaning in facilities, such as a school, can be eliminated.

  Hereinafter, embodiments of a water supply apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 10. 1 to 10, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic diagram illustrating a water supply apparatus 10 according to an embodiment of the present invention. As shown in FIG. 1, the water supply apparatus 10 includes a plurality of pumps 14 connected to a water main 12, a motor 16 that drives the pumps 14, an inverter 18 that controls the rotational frequency of the motor 16, and an inverter 18. And a control unit 20 that controls various devices including the above. The motor 16 is connected to the control unit 20. For example, the control unit 20 monitors the rotational speed of the motor 16 or the pump 14 by an output signal from an optical or magnetic rotary encoder provided in the motor 16. It has become. Here, although the water supply apparatus provided with the several pump 14 is demonstrated, the pump may be one.

The pump 14 of the water supply apparatus 10 is connected to an upstream water supply pipe 22 extending from the water main pipe 12 via a suction pipe 24, and a discharge pipe 26 is connected to the discharge side of the pump 14. Each discharge pipe 26 includes a check valve 28 for preventing water from flowing back from the discharge side to the suction side when the pump 14 is stopped, and maintaining the pressure in the discharge pipe 26. And a flow switch 30 for detecting that the amount of water has decreased. The flow switch 30, the amount of water discharged into the discharge pipe 26 is operated with less than the set amount Q _min from the pump 14, emits under-water detection signal. The flow switch 30 is connected to the control unit 20, and an excessive water amount in the discharge pipe 26 is monitored by the control unit 20 by an output signal of the flow switch 30. When the flow switch 30 is arranged in the vertical discharge pipe, if the vertical discharge pipe is arranged in the same direction as the axial direction of the motor 16, the influence of the flow caused by the fluid discharged from the pump 14 can be avoided. Stable detection is possible.

  As shown in FIG. 1, the discharge pipes 26 from the respective pumps 14 are joined to one joining pipe 32, and the joining pipe 32 includes a pressure sensor 34 that detects the pressure of the joining pipe 32, and the joining pipe 32. A pressure tank 36 for storing water in the pipe 32 is attached via branch pipes 38 and 39, respectively. The pressure sensor 34 is connected to the control unit 20, and the water pressure in the merging pipe 32 (discharge pipe 26) is monitored by the control unit 20 based on an output signal of the pressure sensor 34.

  The merging pipe 32 of the water supply apparatus 10 is connected to a downstream water supply pipe 42 extending to a water supply terminal 40 of a consumer in a building such as a building or a condominium, and the water of the water main 12 is supplied to the consumer by the water supply apparatus 10 described above. To be supplied. These water supply terminals 40 are, for example, a water heater, a water faucet, a flush valve for toilet cleaning, etc. provided in each of the branched downstream water supply pipes 42.

Here, as shown in FIG. 1, an input panel 44 having a display unit such as a liquid crystal screen and a numeric keypad or an increase / decrease button is attached to the control unit 20. Through this input panel 44, the operator can set the upper limit value (upper limit pressure) P _U and lower limit value (lower limit pressure) P _L of the target pressure, the stop pressure P ₀ when the amount of water is too low, the upper limit pressure P _U and the lower limit pressure P. The differential pressure P _D with respect to _L and other information necessary for control can be input. For example, information necessary for the control can be input by pressing a touch panel or a button on the liquid crystal screen of the input panel 44. Moreover, the upper limit pressure P _U and the lower limit pressure P _L are, for example, the conditions when the pump 14 is installed, that is, the height of the building that supplies water, the length of the pipe to the water tap, the pipe resistance, and the discharge to be guaranteed The pressure can be set and changed via the input panel 44 in consideration of the pressure in the pipe.

  As shown in FIG. 1, the control unit 20 includes a central processing unit (CPU) 46, an internal memory 48, and a timer 49. Information input from the input panel 44 is stored in the internal memory 48 via the CPU 46. Is remembered. Inside the control unit 20, a gate control signal of the motor 16 is calculated, and this gate control signal is sent to the inverter 18 to drive the gate transistor in the inverter 18. The inverter 18 sends a speed control signal to the electrically connected motor 16 to drive the pump 14 at a predetermined rotational speed. In driving the pump 14, for example, the pump 14 can be efficiently operated at high speed by controlling the AC voltage steplessly by pulse width modulation (PWM) or pulse amplitude modulation (PAM).

  The control unit 20 performs variable speed control of the rotational speed (rotational frequency) of the pump 14 via the inverter 18 based on information input from the input panel 44, an output signal from the pressure sensor 34, and the like. That is, the control unit 20 controls the inverter 18 to apply a predetermined AC voltage or DC voltage to the motor 16 to increase or decrease the speed of the motor 16. As the rotation of the motor 16 increases, the discharge amount of the pump 14 increases. At this time, although the water pressure in the discharge pipe 26 increases, this pressure is sequentially detected by the pressure sensor 34, and the control unit 20 determines that the pressure detected by the pressure sensor 34 matches the target pressure. The rotational speed of 14 is feedback controlled.

Here are used the water in the water supply terminal 40 of the consumer, when the detection pressure detected falls starting pressure P ₁ below, which is set in advance by the pressure sensor 34, pump 14 of the water supply device 10 is started. When the pump 14 is driven by the motor 16, the water in the water main pipe 12 is sucked into the pump 14 through the suction pipe 24 and discharged to the discharge pipe 26 with a predetermined pressure. The water discharged to the discharge pipe 26 is supplied to the water supply terminal 40 on the demand side through the junction pipe 32 and the downstream water supply pipe 42. The water pumped up by the pump 14 is pressurized to a pressure that can sufficiently supply water to the water supply terminal 40a provided at the highest position in a middle-rise house, a high-rise house, a commercial building, or the like.

If the amount of water used at the feed end 40 decreases during operation of the pump 14 and the flow amount is less than the set amount _Qmin and the flow switch 30 operates, the operation of the pump 14 is stopped. When the pump 14 is stopped, sufficient water is accumulated in the pressure tank 36 by temporarily increasing the operation speed of the pump 14 and increasing the discharge pressure. Eventually, the water in the pressure tank 36 the water supply device 10 is stopped in a state of being raised to a predetermined stop pressure P _0.

Thereafter, when the water is used in the water supply terminal 40, but some time is supplied water from the pressure tank 36, the less water pressure tank 36, the detected pressure of the pressure sensor 34 below starting pressure P ₁ described above When lowered, the pump 14 is started again.

  In addition, you may make it cancel the insufficient water amount detection signal from the flow switch 30 in the fixed time after the start-up of the pump 14 is started. By doing in this way, even if it is a case where water does not flow for a while after the pump 14 starts due to various conditions of the water supply equipment, the pump 14 is stopped by detecting the insufficient water amount. Can be prevented. In addition, when the discharge pressure of the pump 14 is lower than a predetermined value, the control unit 20 may be programmed not to perform the stop process of the pump 14 even if an excessive water amount detection signal is sent from the flow switch 30. . By doing in this way, the discharge pressure during operation of the pump 14 can be prevented from always lowering below a predetermined value, and the frequency of the stop process due to the insufficient amount of water can be reduced.

  Here, as described above, the control unit 20 controls the rotational speed of the pump 14 so that the pressure detected by the pressure sensor 34 matches the target pressure. A discharge pressure constant control for controlling the rotational speed of the pump 14 so that the discharge pressure is constant, or a target value of the discharge pressure of the pump 14 is sequentially calculated so that the terminal pressure of the pipe is constant, and the pump is set to this target value. For example, constant terminal pressure constant control is performed to control the rotational speed of the pump 14 so that the discharge pressures of the 14 coincide with each other. Of these control methods, constant terminal pressure constant control will be described.

  The estimated end pressure is an estimate of the pressure at the highest point and / or the longest pipe end 40a, and this end 40a dominates the target discharge pressure of the pump 14. The discharge pressure of the pump 14 that makes the pressure at this end constant is calculated as the target pressure, and the rotational speed of the pump 14 is controlled so that the discharge pressure of the pump 14 becomes the target pressure.

FIG. 2 shows an operating characteristic curve of the pump 14, where the horizontal axis represents the amount of water and the vertical axis represents the pressure (head or head). Curves N _{1 to} N ₄ indicate the operating characteristics of the pump 14 at each rotational speed, and N ₁ is a characteristic curve at the maximum rotational speed of the pump 14. Here, the resistance curve R is a pipe loss in accordance with the amount of water used from the pump 14 to the water supply terminal 40, and is a curve proportional to the square of the amount of water used Q with the point where the water amount is 0 as the origin.

  In the estimated terminal pressure constant control, the control is performed in consideration of the pipe loss (indicated by the resistance curve R) according to the amount of water used, so that the target pressure is sequentially calculated along the resistance curve R. The calculated target pressure is temporarily stored in the internal memory 48 of the control unit 20. The control unit 20 controls the rotational speed of the pump 14 so that the discharge pressure of the pump 14 becomes the calculated target pressure.

2, the operating point of the maximum rotational speed is the point A _1, the pressure in this respect A ₁ is the upper limit pressure P _U, the amount of water has a Q _1. By reducing the rotational speed of the pump 14, the operating point, the point A ₂ from point A _1, moves on resistance curve R passing through the point A _3. For example, as shown in FIG. 2, the target pressure Px at the time of the water amount Qx is calculated along the resistance curve R, and the rotation speed of the pump 14 is set so that the discharge pressure of the pump 14 becomes the target pressure Px. .

When the amount of water is less than the set amount Q _min and the flow switch 30 is operated, the pump 14 stop process is started. In this pump stopping process, from the target pressure along the resistance curve R described above the target value of the discharge pressure of the pump 14 is temporarily changed to the stop pressure P ₀ set in advance. As a result, the rotational speed of the pump 14 is increased, and finally the discharge pressure of the pump 14 reaches the stop pressure P ₀ and the pump 14 is stopped. In addition, it is preferable that the stop process of the pump 14 is started only after the flow of the flow switch 30 is continued for a certain period of time. For example, the duration of the state of the insufficient water amount can be sequentially changed according to the operation state of the pump 14 immediately before. By doing in this way, the frequency of the stop process of the pump 14 and the starting process of the subsequent pump 14 can be reduced, and the durability of the apparatus can be improved and the life can be extended.

The control unit 20 can calculate the stop pressure P ₀ based on the upper limit pressure P _U and the lower limit pressure P _L stored in the internal memory 48. For example, the stop pressure P ₀ is calculated to be a value equal to or higher than the upper limit pressure P _U. The control unit 20, starting pressure P ₁ of the pump 14 is also adapted to be calculated, for example, the lower limit pressure P _L started and so that a slight underpressure than the equivalent pressure or lower pressure P _L pressure P ₁ Is calculated.

It may also be calculated from the upper limit pressure P _U entered the lower limit pressure P _L. For example, if the highest position of the water supply terminal 40 is a fifth floor building, the upper limit pressure _{P U} and 14m, the upper limit pressure _{P U} about 15% lower 12m or lower limit pressure _{P L.} The reason why the lower limit pressure P _L is set to be about 15% lower than the upper limit pressure P _U is that the pipe resistance is estimated to be about 15%.

For example, the upper limit pressure P _U and the ratio D% may be input via the input panel 44 of the control unit 20 described above, and the lower limit pressure P _L may be obtained by P _L = P _U − (P _U × D%). . Alternatively, the upper limit pressure P _U and the differential pressure P _D may be input, and the lower limit pressure P _L may be obtained by P _L = P _U −P _D. If the upper limit pressure P _U and the lower limit pressure P _L are set to the same value, the discharge pressure constant control can be performed. In this case, the stop pressure P ₀ is P _U (= P _L ) and the starting pressure is P _U -P _D , so that excessive pressurization by the pump 14 is not performed.

  Here, when the above-described water supply apparatus 10 is installed for water supply in a facility such as a school, there may be a shortage of water supply due to simultaneous use of flush valves for toilet cleaning during holidays. In this embodiment, in order to eliminate such a shortage of water supply, the water supply apparatus 10 is started by the method described below.

As described above, water water end 40 is used, the detection pressure of the pressure sensor 34 drops from the stop pressure P _0, the water supply device 10 is started to be the starting pressure P _1. At this time, stores the detected pressure of the pressure sensor 34 in the internal memory 48 at a predetermined time since the start of pressure drop, the value and the reference value, for example, an intermediate value between the stop pressure P ₀ and the starting pressure P ₁ ((P _{0 + P 1) / 2)} ) is compared with. Since the fact that the detected pressure is lower than the reference value indicates that a sudden pressure drop has occurred, this is stored in the internal memory 48. For example, as shown in the graph L _{1 of} FIG. 3, the detected pressure P _{2 at a} predetermined time t ₀ after the pressure drop starts is an intermediate value ((P ₀ + P ₁ ) between the stop pressure P ₀ and the start pressure P _1. If it is lower than / 2)), the internal memory 48 stores that a sudden pressure drop has occurred. On the other hand, as shown in the graph _{L 2,} an intermediate value of the detected pressure _{P 3} at a predetermined time _{t 0} and the stop pressure _{P 0} and the starting pressure _{P 1 ((P 0 + P} 1) / 2)) is higher than Is treated as a normal pressure drop.

When the rapid pressure drop has been stored within the memory 48, by setting higher than P ₁ a starting pressure of the next time the water supply device 10 is started, as soon as possible to the pump 14 to be activated . In this way, when the water supply apparatus 10 is started next time, the pump 14 is started earlier than usual, so that sufficient water supply can be performed even for simultaneous use of a large amount of water.

For example, when the difference between the upper limit pressure P _U and the lower limit pressure P _L is 5 m or more, the starting pressure is set to an intermediate value between the upper limit pressure P _U and the lower limit pressure P _L ((P _U + P _L ) / 2)). can do. When the difference between the upper limit pressure P _U and the lower limit pressure P _L is smaller than 5 m, the starting pressure can be set to a value 2.5 P lower than the upper limit pressure P _U (P _U −2.5). When treated as a normal pressure drop, for example, if the difference between the upper limit pressure P _U and the lower limit pressure P _L is 5 m or more, the starting pressure is P _L , and the upper limit pressure P _U and the lower limit pressure P _L Is smaller than 5 m, the starting pressure can be set to a value (P _U -5) 5 m lower than the upper limit pressure P _U.

In the above example, a sudden pressure drop is determined based on the detected pressure at a predetermined time t ₀ , but it can also be determined based on the time when the detected pressure reaches a predetermined reference value. That is, in the graph of FIG. 3, the time when the pressure detected by the pressure sensor 34 becomes an intermediate value ((P ₀ + P ₁ ) / 2) between the stop pressure P ₀ and the start pressure P ₁ is a predetermined time t. If it is earlier than _0, it can be determined that a sudden pressure drop has occurred, and if it is later than the predetermined time t _0, it can be determined that the pressure drop is normal.

In addition, as shown in FIG. 4, in the process in which the pressure detected by the pressure sensor 34 changes from the stop pressure P ₀ to the start pressure P ₁ at the start of the water supply device 10, the decrease ΔP in the detected pressure during an arbitrary period Δt is The start pressure at the next start may be increased when the difference is larger than a predetermined ratio with respect to the difference (P ₀ −P ₁ ) between the stop pressure P ₀ and the start pressure P ₁ .

  By such a method, it is possible to solve a shortage of water supply pressure that occurs when a flush valve for toilet cleaning is used at the same time. In addition to this method, the following method can also be performed to solve the shortage of water supply pressure.

  For example, the timer 49 built in the control unit 20 is provided with a date / time recognition function (clock function), and a large amount of water is temporarily used due to simultaneous use of flush valves for toilet cleaning. When the pressure falls below a preset pressure, the day and time of the day are stored in the internal memory 48. In schools and the like, it is considered that the same water shortage will occur at the same time on the same day of the next week. Therefore, when several minutes before the same time on the same day of the next week, the pump 14 May be forcibly operated for a predetermined time. Even with such a method, it is possible to solve the shortage of the supply water pressure at the start due to a rapid pressure drop.

  In this case, when a large amount of water is actually used during the forced operation of the pump 14 and a pressure fluctuation occurs, the same forced operation is performed at the same time on the same day of the next week to change the pressure fluctuation. If this does not occur, the normal operation may be performed without performing the forced operation of the pump 14 at the same time on the same day of the next week.

  Normally, when the pump 14 is started, the operating frequency of the motor 16 is determined from the pressure detected by the pressure sensor 34, and the pump 14 is started at the determined frequency. For this reason, when the pump 14 is started in a state where the amount of water is large, a time lag of pump activation by the inverter 18 may occur, and a pressure drop may occur. In order to eliminate this, first, when the water supply device 10 is started, the pump 14 is started at the maximum operating frequency regardless of the calculated target pressure, and then the estimated terminal pressure constant control or the discharge pressure constant control after a predetermined time has elapsed. You may move to. In this case, when the frequency of the pump 14 is increased to the maximum operating frequency at the time of startup, an S-shaped acceleration operation may be performed in which the frequency is changed so that the time change of the frequency draws an S shape on the graph. The time until the frequency is reached may be set shorter than the normal time.

  Further, as shown in FIG. 5, the water supply apparatus includes a pump 14 a driven by the motor 16 controlled by the inverter 18 and a pump 14 b driven by the motor 16 directly connected to the commercial power source 60. In this case, normally, the pump 14a with the inverter 18 is driven first for energy saving, and then the pump 14b directly connected to the commercial power source 60 is driven when the amount of water is insufficient. However, as described above, the pump 14a with the inverter 18 has a time lag at the time of start-up, and therefore, when a sudden pressure drop occurs, there is a possibility that the supply water pressure is insufficient. In order to eliminate such a shortage of water supply pressure, when the water supply device is started, the pump 14b directly connected to the commercial power source 60 is first driven to start the pump 14b instantly, and then the inverter 18 with the inverter 18 is attached after a predetermined time has elapsed. The pump 14a may be driven.

  In addition, when the water supply terminal 40a is a toilet or the like, when a human sensor that reacts to a person sitting on the toilet seat or standing in front of the toilet is installed in the toilet, the human sensor is activated. The pump may be forcibly activated for a predetermined time regardless of the actual water usage.

  6 is a front view showing an example of the structure of the water supply apparatus 10 shown in FIG. 1, and FIG. 7 is a plan view of FIG. As shown in FIGS. 6 and 7, the water supply apparatus 10 includes two pumps 14 installed on the base 50, two motors 16 that drive the pumps 14, and the rotational speed of each motor 16. And a control unit 20 for controlling.

  Each pump 14 is provided with a suction pipe 24 for sucking water from the upstream water supply pipe and a discharge pipe 26 for discharging pressurized water. Each discharge pipe 26 is provided with a flow switch 30 that detects that the amount of water in the discharge pipe 26 is less than a predetermined amount. Further, these discharge pipes 26 are joined to a joining pipe 32. A pressure tank 36 is installed on the base 50 between the two pumps 14, and the pressure tank 36 is connected to the junction pipe 32. Further, the junction pipe 32 is provided with a pressure sensor 34 for detecting the pressure of the discharged water.

  In the water supply apparatus 10 having such a configuration, the water sucked from the suction pipe 24 is pressurized by the pump 14, then discharged from the discharge port 52 through the junction pipe 32, and the water supply terminal via the downstream water supply pipe. To be supplied. Here, the rotational speed of each motor 16 is variably controlled so that the pressure on the discharge side of the pump 14 becomes a predetermined target pressure.

  In order to prevent vibration of the entire water supply apparatus 10, it is preferable to form a notch hole (not shown) at an arbitrary position of the base 50. An anti-vibration effect can be obtained by forming such a notch hole at the resonance point of vibration. Further, by providing a rib (not shown) on the base 50, a further vibration isolation effect can be obtained. The shape of the cutout hole may be any shape as long as it does not have a corner portion where another resonance point is generated. For example, a circular or elliptical cutout hole can be provided.

  In the above-described example, the water supply apparatus 10 including two pumps 14 has been described, but the number of pumps 14 is not limited to two. 8 and 9 are examples of a water supply apparatus 110 including five pumps, FIG. 8 is a front view, and FIG. 9 is a plan view. As shown in FIGS. 8 and 9, the water supply device 110 controls five pumps 114 a and 114 b installed on the base 150, motors 116 that drive the respective pumps, and the rotation speed of each motor 116. And a control unit 120.

  A suction pipe 124 for sucking water from the upstream water supply pipe and a discharge pipe 126 for discharging pressurized water are attached to each pump 114a, 114b. Each discharge pipe 126 is provided with a flow switch 130 for detecting that the amount of water in the discharge pipe 126 is less than a predetermined amount.

  The water supply apparatus 110 shown in FIGS. 8 and 9 includes a first junction pipe 132a connected to the discharge pipe 126 of the three pumps 114a and a second junction pipe 132b connected to the discharge pipe 126 of the pump 114b. It has a structure in which two are connected. In this way, by connecting an arbitrary number of additional units 133b composed of one pump 114b to the base unit 133a composed of three pumps 114a in the arrangement direction of the pumps 114a, the user's request can be met. It is possible to easily configure a water supply device having a corresponding number of pumps.

  Further, the first joining pipe 132a is provided with a pressure sensor 134 for detecting the pressure of the discharged water. A pressure tank 136 is installed on the base 150, and the pressure tank 136 is connected to the first junction pipe 132a. Thus, by installing the pressure tank 136 in parallel with the pumps 114a and 114b in the lower part of the control unit 120, it is possible to prevent water in the pressure tank 136 from being applied to the control unit 120 during maintenance and replacement of the pressure tank 136. Is done.

  In this example, a blind flange 154 is attached to the end of the first joining pipe 132a, and a discharge port 152 is formed at the end of the second joining pipe 132b on the opposite side. In addition, the blind flange 154 may be attached to the end of the second merge pipe 132b, and the discharge port 152 may be formed at the end of the first merge pipe 132a.

  In the water supply apparatus 110 having such a configuration, the water sucked from the suction pipe 124 is pressurized by the pumps 114a and 114b, and then discharged from the discharge port 152 through the merge pipes 132a and 132b, and is supplied to the downstream water supply pipe. To the water supply terminal. Here, the rotation speed of each motor 116 is variably controlled so that the pressure on the discharge side of the pump 14 becomes a predetermined target pressure.

  When a large number of pumps are provided as in the water supply device 110 shown in FIGS. 8 and 9, the sudden pressure drop described above can be dealt with by the method shown in the flowchart of FIG. . That is, when the water supply apparatus 110 is started, a plurality of pumps, for example, five pumps 114a and 114b (hereinafter, the pumps 114a and 114b are collectively denoted by reference numeral 114) are simultaneously activated. At this time, all the pumps 114 are operated at the same speed (same frequency) (uniform speed starting step S1). In this way, by simultaneously starting the plurality of pumps 114 at the time of starting the water supply apparatus 110, it is possible to solve the shortage of the supply water pressure at the start due to a rapid pressure drop.

After the start of the water supply device 110, when a predetermined time has elapsed, the difference between the frequency _{F L} of the motor 116 corresponding to the lower limit pressure _{P L} as described above and the operating frequencies _{F 1} of the motor 116 _(F 1 -F _L) is , it is determined whether the motor difference between operating a maximum frequency _{F max} and the lower limit frequency _{F L} of 116 _(F max -F _L) of (n-1) is / n or less (frequency determination step S2). Here, n is the number of pumps 114 that are operating.

When F ₁ -F _L is equal to or less than (n−1) / n of F _max −F _{L in} the frequency determination step S2, _{one of the} n pumps 114 in operation is stopped ( Stop process (disconnection operation S3) At this time, it is determined whether or not the number of operating pumps 114 is one (unit number determination step S4). When there are a plurality of operating pumps 114, the process returns to the above-described frequency determination step S2 and the above-described processing is repeated until the number of pumps becomes one (repetition step). also determination whether it is possible to maintain the current target pressure, by carrying out on the basis of the frequency F _L, can be reduced to the number of operating units of the proper pump. the frequency determination in the present embodiment process S2 However, if more than three pumps are operating, it may be determined whether a plurality of pumps may be stopped. Good.

If F ₁ -F _L is not less than (n−1) / n of F _max −F _{L in} the frequency determination step S2, the frequency of the motor 116 of at least one pump 114 is fixed and the other The frequency of the motor 116 of the pump 114 is changed (operation transition step S5).

  As described above, according to the example shown in FIG. 10, since the plurality of pumps 114 are simultaneously activated when the water supply device 110 is started, the shortage of the supply water pressure at the start due to a rapid pressure drop can be solved.

  In addition, in the above-mentioned embodiment, although the case where the water supply apparatus was directly connected to the water main was demonstrated, it is not restricted to this, For example, the water receiving tank which stores tap water once upstream of a water supply apparatus is used. It is good also as installing and supplying the water stored by this water-receiving tank to each consumer with a water supply apparatus.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

It is a schematic diagram which shows the water supply apparatus in one Embodiment of this invention. It is a graph which shows the driving | operation characteristic curve of the pump in the water supply apparatus shown in FIG. It is a graph which shows an example of the pressure change at the time of starting of the water supply apparatus shown in FIG. It is a graph which shows the other example of the pressure change at the time of starting of the water supply apparatus shown in FIG. It is a schematic diagram which shows the water supply apparatus in other embodiment of this invention. It is a front view which shows an example of the structure of the water supply apparatus shown in FIG. FIG. 7 is a plan view of FIG. 6. It is a front view which shows the other example of the structure of the water supply apparatus shown in FIG. It is a top view of FIG. It is a flowchart which shows the starting method of the water supply apparatus in other embodiment of this invention.

Explanation of symbols

10, 110 Water supply device 12 Water main pipe 14, 114a, 114b Pump 16, 116 Motor 18 Inverter 20 Control unit 22 Upstream water supply pipe 24, 124 Suction pipe 26, 126 Discharge pipe 28 Check valve 30, 130 Flow switch 32, 132a , 132b Merge pipes 34, 134 Pressure sensors 36, 136 Pressure tanks 38, 39 Branch pipe 40 Feed water end 42 Downstream feed pipe 44 Input panel 46 CPU
48 Internal memory 49 Timer 50, 150 Base 52, 152 Discharge port

Claims (9)

A uniform speed starting step of starting the motors of a plurality of pumps at the same frequency;
The difference between the operating frequency of the n motors operating at the same frequency and the lower limit frequency corresponding to the lower limit value of the target pressure is the difference between the maximum operating frequency of the motor and the lower limit frequency (n−1) / a frequency determination step of determining whether or not n or less;
When it is determined in the frequency determination step that it is (n-1) / n or less, after repeating one of the pumps being operated, the repetition step of repeating the frequency determination step;
An operation transition step of fixing the frequency of the motor of at least one pump and changing the frequency of the motor of another pump when it is determined that it is not less than (n-1) / n in the frequency determination step;
A method for starting a water supply apparatus, comprising:   2. The water supply apparatus starting method according to claim 1, wherein the repetitive step is repeated until one pump is operated. A method of starting a water supply device when a detected pressure falls below a predetermined start pressure from a predetermined stop pressure,
In the process in which the detected pressure changes from the predetermined stop pressure to the predetermined start pressure, when the detected pressure at a predetermined reference time is lower than a predetermined reference value, the start pressure at the next start is increased. A method for starting a water supply apparatus. A method of starting a water supply device when a detected pressure falls below a predetermined start pressure from a predetermined stop pressure,
In the process in which the detected pressure changes from the predetermined stop pressure to the predetermined start pressure, when the time when the pressure of the predetermined reference value is detected is earlier than the predetermined reference time, the start pressure at the next start A method for starting a water supply device, characterized in that   The water supply device start method according to claim 3 or 4, wherein the predetermined reference value is an intermediate value between the stop-time pressure and the start pressure. A method of starting a water supply device when a detected pressure falls below a predetermined start pressure from a predetermined stop pressure,
In the process in which the detected pressure changes from the predetermined stop pressure to the predetermined start pressure, when a decrease in the detected pressure in a predetermined period is greater than a predetermined ratio with respect to the difference between the stop pressure and the start pressure The method for starting the water supply apparatus is characterized by increasing the starting pressure at the next start. A uniform speed starting step of starting the motors of a plurality of pumps at the same frequency;
Based on the operating frequency of the plurality of motors operating at the same frequency, a frequency determining step for determining whether or not some of the plurality of operating pumps may be stopped,
A stop step of stopping a part of the pump being operated when it is determined that the frequency determination step may stop,
A method for starting a water supply apparatus, comprising:   8. The water supply apparatus starting method according to claim 7, further comprising an operation transition step of fixing a frequency of a motor of at least one pump when it is determined that it is not necessary to stop in the frequency determination step. . Multiple pumps,
A motor for driving the plurality of pumps;
A controller that controls the speed of the motor so that the pressure on the discharge side of the pump is maintained at a predetermined pressure;
With
The controller is
A uniform speed starting step of starting the motors of the plurality of pumps at the same frequency;
The difference between the operating frequency of the n motors operating at the same frequency and the lower limit frequency corresponding to the lower limit value of the target pressure is the difference between the maximum operating frequency of the motor and the lower limit frequency (n−1) / a frequency determination step of determining whether or not n or less;
When it is determined in the frequency determination step that it is (n-1) / n or less, after repeating one of the pumps being operated, the repetition step of repeating the frequency determination step;
An operation transition step of fixing the frequency of the motor of at least one pump and changing the frequency of the motor of another pump when it is determined that it is not less than (n-1) / n in the frequency determination step;
It is comprised so that it may perform, The water supply apparatus characterized by the above-mentioned.

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