JP5857089B2 - Liquid supply device - Google Patents

Description

  The present invention relates to a liquid supply apparatus including a plurality of pumps capable of changing an operation frequency.

  Conventionally, a water supply apparatus has been proposed that includes a plurality of variable-speed pumps whose operation speed can be changed by inverter control. The operation frequency of the pump can be changed by a drive unit such as an electric motor that drives the pump and an inverter that adjusts the operation frequency of the drive unit.

  In this type of water supply apparatus, a discharge pressure sensor that detects the pressure in the pipe is provided in a pipe that sends water discharged from a plurality of pumps to the water receiving side. The detection result of the discharge pressure sensor is transmitted to the control panel. Further, a flow rate detection switch for detecting the flow rate of water discharged from the pump is provided on the discharge side of each pump. When the flow rate switch exceeds a preset flow rate, the flow rate switch is turned on and transmits a signal to the control panel.

  The control panel adjusts the number of pumps to be operated based on the detection result of the pressure detection unit, flow switch on / off information, and the operating frequency of the operating pump, and the operating frequency of the operating pump. (For example, refer patent document 1).

Japanese Patent Laid-Open No. 7-224765

  During the operation of the water supply apparatus, there may be a momentary fluctuation in the pressure in the pipe. Specifically, the pressure drops instantaneously and returns immediately after that. Alternatively, the discharge pressure may increase immediately and then return immediately. The cause may be due to the configuration of the water supply device.

  Further, the pressure and flow rate in the pipe may fluctuate due to the air layer in the pipe. The pressure fluctuation in the piping caused by the air layer will be specifically described. There may be an air layer in the piping. This air layer is generated, for example, during installation work of piping. Alternatively, for example, when a flush valve is used, such as a toilet, a pressure tank communicating with the pipe is provided near the pipe outlet. The pressure tank is provided with an air layer in order to cope with a sudden change in flow rate in the piping caused by the operation of the flash valve.

  The volume change of the air layer that occurs in response to a change in pressure is larger than the volume change in water that occurs in response to a change in pressure. A change in the volume of the air layer causes a change in flow rate and a change in pressure, and thus may act as a disturbance when controlling a change in the flow rate of water in the pipe.

  On the other hand, in a water supply apparatus including a plurality of pumps, it is preferable that a small number of pumps are operated according to the amount of water used from the viewpoint of energy saving.

  However, as described above, the control panel repeatedly increases or decreases the number of operating pumps due to pressure fluctuations in a short period of time or flow rate fluctuations and pressure fluctuations caused by the air layer in the piping. Specifically, the number of pumps decreases by one immediately after the number of pumps increases by one. Thus, it is not preferable that the increase or decrease of the number of pumps is repeated.

  An object of this invention is to provide the liquid supply apparatus which can suppress generation | occurrence | production of the increase / decrease in the increase / decrease in the number of operating pumps.

  The liquid supply apparatus of the present invention includes a plurality of pumps, an operation frequency adjusting unit that is provided in each of the plurality of pumps, and is capable of adjusting an operation frequency of the provided pump, and liquid discharged from the plurality of pumps. And a controller that controls the operations of the plurality of pumps.

  The operating frequency adjusting unit includes a driving unit that drives the pump, and an inverter that can adjust a frequency of electric power supplied to the driving unit.

  The control unit is capable of controlling the inverter, and when a condition for increasing the number of pumps to be operated is satisfied, the number of units is increased during a preset standby time after the increase condition is satisfied. When the reduction condition for reducing the number of pumps to be operated is satisfied, the reduction is restricted during a preset reduction waiting time after the reduction condition is satisfied, and the number of pumps to be operated is 1 When the number of operating units is reduced within the preset monitoring time from the time when the number of units is increased, the number of units to be operated is increased to limit the number of operating units continuously in succession to the next waiting time for adding units. Set the base time limit.

  According to the present invention, it is possible to suppress the occurrence of repeated increase / decrease in the number of operating pumps.

Schematic which shows the water supply apparatus concerning one Embodiment of this invention. The graph which shows the operating frequency of the pump which is drive | operating among the pumps with which the same water supply apparatus is equipped. The graph which shows the driving | running frequency of the pump which carries out the same operation of the state which time passed from the state of FIG. The graph which shows the driving | running frequency of the pump which carries out the same operation of the state which time passed from the state of FIG. The graph which shows the operating frequency of the pump which is drive | operating. The graph which shows the operating frequency of the pump which carries out the same operation in the state where time has passed from the state of FIG. The graph which shows the driving | running frequency of the pump which carries out the same operation of the state which time passed from the state of FIG. The graph which shows the state in which the pressure in the water supply piping system of the same water supply apparatus raises instantaneously, and a reduction | decrease stand condition is satisfied. The graph which shows the state in which the pressure in the water supply piping system decreased instantaneously, and the stand-up condition was satisfied. Schematic which shows the water supply apparatus for description. The schematic diagram which shows the water supply apparatus for description of the state of time t8 having passed since the description pump was drive | operated because the discharge pressure value in the water supply piping system for description became a starting pressure. The graph which shows the change of the discharge pressure with progress of time from the state in which the discharge pressure became the starting pressure in the water supply piping system for description of the water supply apparatus for description. The graph which shows operation | movement of the water supply apparatus which has only the 1st-7th function when the fluctuation | variation of discharge pressure and the flow volume fluctuate due to the air layer in a water supply piping system. The graph which shows operation | movement of the water supply apparatus which has a 1st-14th function. The graph which shows the relationship between the water supply amount and discharge pressure of the water supply apparatus. The graph which shows the frequency of the pump currently drive | operating in the water supply apparatus. The graph which shows operation | movement of the water supply apparatus of the embodiment.

  The water supply apparatus which concerns on one Embodiment of this invention is demonstrated using FIGS. A water supply apparatus is an example of the liquid supply apparatus said by this invention. The water supply apparatus 10 supplies water, which is an example of a liquid, to the receiving side. FIG. 1 is a schematic view showing a water supply device 10. As shown in FIG. 1, the water supply apparatus 10 supplies water to the 1st and 2nd faucets 1 and 2 which are examples of a receiving side.

  The water supply apparatus 10 includes a water supply piping system 20, a pressure tank 30, a first pump unit 40, a second pump unit 50, a third pump unit 60, a first flow switch 70, a second The flow rate switch 80, the third flow rate switch 90, the discharge pressure sensor 100, the control panel 110, and the power supply device 200 are provided.

  The water supply piping system 20 guides water discharged from pump units 40 to 60 described later to the first and second faucets 1 and 2. The feed water piping system 20 includes a first upstream branch pipe 21, a second upstream branch pipe 22, a third upstream branch pipe 23, a merge pipe 24, and a first downstream branch pipe 25. The second downstream branch pipe 26 is provided.

  The first upstream branch pipe 21 is formed of, for example, a pipe member. The first upstream branch pipe 21 is connected to a water supply side such as a water receiving tank or a water main, for example. The first upstream branch pipe 21 is formed such that water supplied from the water supply side can be guided to the first and second faucets 1 and 2 side.

  The second upstream branch pipe 22 is formed of, for example, a pipe member. The second upstream branch pipe 22 is connected to the water supply side. The second upstream branch pipe 22 is formed such that water supplied from the water supply side can be guided to the first and second faucets 1 and 2 side.

  The third upstream branch pipe 23 is formed of, for example, a pipe member. The third upstream branch pipe 23 is connected to the water supply side. The third upstream branch pipe 23 is formed so as to be able to guide the water supplied from the water supply side to the first and second faucets 1 and 2.

  The merge pipe 24 is formed from, for example, a pipe member. The junction pipe 24 is connected to the downstream ends of the upstream branch pipes 21 to 23. The merging pipe 24 is formed so as to be able to guide the water flowing in from the upstream branch pipes 21 to 23 to the first and second faucets 1 and 2 side.

  The first downstream branch pipe 25 is formed of, for example, a pipe member. The first downstream branch pipe 25 is connected to the downstream end of the merge pipe 24 and the first faucet 1. The first downstream branch pipe 25 is formed so that water flowing through the merge pipe 24 can be guided to the first faucet 1.

  The second downstream branch pipe 26 is formed of, for example, a pipe member. The second downstream branch pipe 26 is connected to the downstream end of the merge pipe 24 and the second faucet 2. The second downstream branch pipe 26 is formed so that water flowing through the merge pipe 24 can be guided to the second faucet 2.

  As shown in the figure, the second downstream branch pipe 26 has a plurality of curved portions 27. This is because the second downstream branch pipe 26 is formed in accordance with the place where the second faucet 2 is provided. An air layer 28 exists at the upper end of the curved portion 27 of the second downstream branch pipe 26. The air layer 28 is formed by air accumulated in the second downstream branch pipe 26 when the second downstream branch pipe 26 is constructed.

  The first pump unit 40 includes a first pump 41 and a first drive unit 42. The first pump 41 is provided in the first upstream branch pipe 21. The first pump 41 includes, for example, a housing communicating with the first upstream branch pipe 21 and an impeller accommodated in the housing. This impeller is formed so as to be able to increase the pressure of water supplied from the water supply side and to discharge it downstream, by rotating.

The 1st drive part 42 is formed so that the impeller of the 1st pump 41 can rotate. The first drive unit 42 is, for example, an electric motor. The second pump unit 50 includes a second pump 51 and a second drive unit 52. The second pump 51 is provided in the second upstream branch pipe 22. The second pump 51 includes, for example, a housing communicating with the second upstream branch pipe 22 and an impeller accommodated in the housing. This impeller is formed so as to be able to increase the pressure of water supplied from the water supply side and to discharge it downstream, by rotating.

  The 2nd drive part 52 is formed so that the impeller of the 2nd pump 51 can rotate. The second drive unit 52 is, for example, an electric motor.

  The third pump unit 60 includes a third pump 61 and a third drive unit 62. The third pump 61 is provided in the third upstream branch pipe 23. The third pump 61 includes a housing that communicates with the third upstream branch pipe 23 and an impeller that is accommodated in the housing. This impeller is formed so as to be able to increase the pressure of water supplied from the water supply side and to discharge it downstream, by rotating.

  The 3rd drive part 62 is formed so that the impeller of the 3rd pump 61 can rotate. The third drive unit 62 is, for example, an electric motor.

  In the present embodiment, the pump units 40 to 60 are the same. That is, the pumps 41 to 61 are the same as each other, and the drive units 42 to 62 are the same as each other.

  The first flow switch 70 is provided at a position downstream of the first pump 41 in the first upstream branch pipe 21. The first flow rate switch 70 is turned on when the flow rate of water discharged from the first pump 41 is equal to or higher than a predetermined flow rate set in advance. When the flow rate of the water discharged from the first pump 41 is less than a predetermined flow rate, it is turned off. When the first flow switch 70 is turned on, the first flow switch 70 is configured to be able to transmit a signal to the microcomputer 111 of the control panel 110 described later. The first flow switch 70 does not transmit a signal in the off state.

  The second flow rate switch 80 is provided at a position downstream of the second pump 51 in the second upstream branch pipe 22. The second flow rate switch 80 is turned on when the flow rate of water discharged from the second pump 51 is equal to or higher than a predetermined flow rate set in advance. When the flow rate of the water discharged from the second pump 51 is less than the predetermined flow rate, it is turned off. When the second flow rate switch 80 is turned on, the second flow rate switch 80 is configured to transmit a signal to the microcomputer 111 of the control panel 110 described later. The second flow rate switch 80 does not transmit a signal in the off state.

  The third flow rate switch 90 is provided at a position downstream of the third pump 61 in the third upstream branch pipe 23. The third flow rate switch 90 is turned on when the flow rate of water discharged from the third pump 61 is equal to or higher than a predetermined flow rate set in advance. When the flow rate of the water discharged from the third pump 61 is less than the predetermined flow rate, it is turned off. When the third flow switch 90 is turned on, the third flow switch 90 is configured to transmit a signal to the microcomputer 111 of the control panel 110 described later. The third flow switch 90 does not transmit a signal in the off state.

  In the present embodiment, the flow switches 70 to 90 are the same. The predetermined flow rates at which the flow rate switches 70 to 90 are turned on have the same value.

  The discharge pressure sensor 100 is provided in the merging pipe 24. The discharge pressure sensor 100 is formed so as to be able to detect the pressure in the merging pipe 24. The discharge pressure sensor 100 is formed so that the detection result can be transmitted to the microcomputer 111 of the control panel 110.

  In this embodiment, the water supply apparatus 10 is a structure provided with the pump units 40-60 as an example of a structure provided with a some pump unit, ie, a structure provided with three pump units. The number of pump units provided in the water supply apparatus 10 may be other than three. As an example of a configuration including pumps other than three, a fourth pump unit 300 which is the fourth pump unit in FIG. 1 is indicated by a two-dot chain line. The configuration of the fourth pump unit is the same as that of the pump units 40-60.

  The fourth pump unit 300 is provided in a fourth upstream branch pipe 29 similar to the upstream branch pipes 21 to 23. The fourth upstream branch pipe 29 is connected to the water supply side and the merging pipe 24. The fourth upstream branch pipe 29 is provided with a fourth diversion switch 400 similar to the flow rate switches 70 to 90. Thus, when the water supply apparatus 10 includes a plurality of pumps, a flow rate switch that detects the discharge flow rate of each pump is provided, such as the flow rate switches 70 to 90.

  The pressure tank 30 is provided with a merging pipe 24. The pressure tank 30 communicates with the merging pipe 24. An air layer 31 is provided in the pressure tank 30. The air layer 31 is a portion of the pressure tank 30 that is not filled with water, and contains air. When the pressure in the merging pipe 24 fluctuates rapidly, the water in the pressure tank 30 flows into the merging pipe 24 by the air layer 31 in the pressure tank 30 or the water in the merging pipe 24 flows into the pressure tank 30. Flows in. As a result, a sudden change in the amount of water in the junction pipe 24 is absorbed.

  The control panel 110 includes a first inverter 43 formed to be capable of adjusting the frequency of power supplied to the first drive unit 42 of the first pump 41, and a second drive unit 52 of the second pump 51. The second inverter 53 formed so that the frequency of power supplied to the second inverter 53 can be adjusted, and the third inverter formed so that the frequency of power supplied to the third drive unit 62 of the third pump 61 can be adjusted. The inverter 63 and the microcomputer (control part) 111 formed so that control of the inverters 43, 53, and 63 is possible.

  The first inverter 43 is connected to the power supply device 200. The first inverter 43 can adjust the frequency of the power supplied from the power supply device 200 under the control of the microcomputer 111 and can supply the adjusted power to the first drive unit 42.

  The second inverter 53 is connected to the power supply device 200. The second inverter 53 is configured to be able to adjust the frequency of the power supplied from the power supply device 200 under the control of the microcomputer 111 and to be able to supply the adjusted power to the second drive unit 52.

  The third inverter 63 is connected to the power supply device 200. The third inverter 63 is configured to be able to adjust the frequency of the power supplied from the power supply device 200 under the control of the microcomputer 111 and to supply the adjusted power to the third drive unit 62.

  The detection results of the flow rate switches 70 to 90 and the detection result of the discharge pressure sensor 100 are transmitted to the microcomputer 111. The microcomputer 111 is configured to be able to control the operation of the inverters 43 to 63 based on the detection results of the flow switches 70 to 90, the detection result of the discharge pressure sensor 100, and the operation frequency of the pumps 41 to 61.

  The operating frequency of the pumps 41 to 61 is the rotational speed of each impeller of the pumps 41 to 61. The rotation speed of the impellers of the pumps 41 to 61 corresponds to the frequency of AC power supplied from the inverters 43 to 63 to the drive units 42 to 62. The microcomputer 111 calculates the rotational speed of the impellers of the pumps 41 to 61 based on the information on the frequency of the AC power supplied from the inverters 43 to 63 to the drive units 42 to 62. In other words, the operating frequency of the pumps 41 to 61 is calculated.

  Thus, in this embodiment, the microcomputer 111 of the control panel 110 has a function of detecting the operating frequency of the pumps 41 to 61. As another example, for example, each of the pumps 41 to 61 may be provided with a detection unit that detects the rotational speed of the impeller. In this case, the detection result of this detection unit is transmitted to the microcomputer 111 of the control panel 110.

  The microcomputer 111 of the control panel 110 has first to fourteen functions. The first function is a function for determining the operating frequency of the pump to be operated. Specifically, the microcomputer 111 of the control panel 110 determines the operation frequency of the pump in the variable speed operation state so that the detection result of the discharge pressure sensor 100 becomes the set pressure value. The set pressure value is a value set so that the water supply apparatus 10 discharges water at a constant pressure set in advance from the first and second faucets 1 and 2 and a value in the vicinity of this pressure. As described above, in the present embodiment, the microcomputer 111 of the control panel 110 determines the operation frequency of the pump in the variable speed operation state by feeding back the discharge pressure, in other words, the detection result of the discharge pressure sensor 100.

  The pump in the variable speed operation state will be specifically described. The microcomputer 111 of the control panel 110 may operate a plurality of pumps in parallel so that the discharge pressure in the water supply piping system 20 becomes a set pressure value. For example, the first and second pumps 41 and 51 are operated. In this case, the operation frequency of the pump that has started operation is fixed at the maximum operation frequency. That is, the pump that has started operation performs constant speed operation. And the pressure in the feed water piping system 20 is adjusted by adjusting the operation frequency of the pump which started operation last. The pump in the variable speed operation state is a pump whose operation frequency is adjusted as described above.

  The second function is a function that determines whether the condition for increasing the number of pumps to be operated is satisfied. Specifically, the control panel 110 detects the discharge pressure sensor 100, the detection result of the flow switch provided downstream of the operating pump among the flow switches 70 to 90, and the operation of the pumps 41 to 61. Based on the operating frequency of the pump being operated, it is determined whether or not the condition for adding the platform is satisfied.

  More specifically, the microcomputer 111 of the control panel 110 indicates that the discharge pressure detection result is less than the set pressure value, the operating frequency of the pump that is variably operating is the maximum operating frequency, and the downstream of the pump in the variable speed operating state. When the flow rate water switch provided in is in the on state, it is determined that the condition for adding the platform is satisfied.

  The third function is a function for determining whether or not the condition for reducing the number of operating pumps is satisfied. Specifically, the microcomputer 111 of the control panel 110 detects the detection result of the discharge pressure sensor 100, the detection result of the flow rate switch provided downstream of the operating pump among the flow rate switches 70 to 90, and the pumps 41 to 61. Based on the operating frequency of the pump that is operating, it is determined whether or not the condition for reducing the vehicle is satisfied.

  More specifically, the microcomputer 111 of the control panel 110 indicates that the result of the discharge pressure sensor 100 is greater than the set pressure value, the operating frequency of the pump in the variable operation state is less than the maximum operating frequency, and the pump in the variable speed operation state. When the flow rate water switch provided downstream is in an OFF state, it is determined that the reduction table condition is satisfied. Note that the flow switch is in an OFF state is a state where the flow switch is not transmitting a signal and the microcomputer 111 of the control panel 110 is not receiving a signal.

  The fourth function is a function of restricting the increase of the number of units during the unit standby time A after determining that the condition for adding the units is satisfied. The stand-by time for adding a base A is set based on the time at which the fluctuation that occurs instantaneously and the pressure rises is converged, and is set longer than the time to converge. The instantaneous pressure fluctuations referred to here are caused by, for example, the configuration of the water supply apparatus 10. The additional stand standby time A can be determined in advance based on the time at which instantaneous fluctuations obtained by, for example, experiments converge. In the present embodiment, the additional stand standby time A is a constant value. Further, restricting the number of units to be added here means not to increase the number of units.

  The fifth function is a function of limiting the reduction of the vehicle during the reduction standby time B after it is determined that the reduction condition is satisfied. The reduction stand-by time B is set on the basis of the time when the fluctuation that occurs instantaneously and the pressure decreases is set, and is set longer than the time for the convergence. The instantaneous pressure fluctuations referred to here are caused by, for example, the configuration of the water supply apparatus 10. The stand-by waiting time B can be determined in advance based on the time at which instantaneous fluctuations obtained by, for example, experiments converge. In the present embodiment, the stand-by waiting time B is a constant value. In addition, restricting the number of units to be reduced here means not to reduce the number of units.

  The sixth function is a function to increase the number of pumps to be operated by one when the increase condition is satisfied after the increase standby time A has elapsed. Specifically, the microcomputer 111 of the control panel 110 controls the inverter of the pump unit whose operation is stopped in order to operate one of the pumps that is not operating.

  The seventh function is a function to reduce the number of operating pumps by one when the reduction condition is satisfied after the reduction standby time B has elapsed. Specifically, the microcomputer 111 of the control panel 110 controls the inverter of the pump unit that is operated first among the pumps that are operating, and stops the driving of the pump.

  The eighth function is a function for measuring the elapsed time from the time when the number of units is increased until the time when the number of units is reduced.

  The ninth function is a function of comparing the monitoring time X with the measurement time Y measured by the eighth function from the time when the number of units is increased until the time when the number of units is decreased. The monitoring time X is a time set to determine whether or not the pressure fluctuation in the feed water piping system 20 is caused by the air layer 28 in the feed water piping system 20. The monitoring time X will be specifically described.

  As described above, when the discharge pressure fluctuates due to the air layer in the feed water piping system 20, the discharge pressure value starts to increase rapidly and then decreases. The period from when the rise starts until it falls is due to the configuration of the water supply apparatus 10. For example, it results from the volume of the air layer in the feed water piping system 20 and the performance of each pump unit. For this reason, the time from when the discharge pressure in the water supply piping system 20 suddenly increases due to the air layer to when the discharge pressure decreases below the set pressure value can be obtained, for example, by an experiment.

  In the tenth function, when the comparison result of the ninth function is that the measurement time Y is included in the monitoring time X, the increase condition and the decrease condition are caused by the air layer. This is a function for setting the additional time limit Z after the additional standby time A after the additional standby time A has elapsed. The microcomputer 111 of the control panel 110 limits the increase of the number of times within the time limit for increasing the number Z even if the condition for increasing the number is satisfied.

  This is because in the case of a variation in the discharge pressure caused by the air layer 28, the pressure variation is settled after a while. The monitoring time X is a value set based on the time when pressure fluctuation caused by the air layer subsides. The time required for the pressure fluctuation caused by the air layer 28 to settle is based on the configuration of the water supply apparatus 10. For this reason, the monitoring time X can be determined in advance by experiments or the like.

  The eleventh function raises the operating frequency of the pump being operated within a range from the maximum operating frequency to the maximum operating excess frequency when the increasing condition is satisfied within the additional time limit Z.

  Here, the maximum operation frequency and the maximum operation excess frequency will be specifically described. The maximum operating frequency is set to an operating frequency at which the pump units 40 to 60 do not fail. The maximum operation frequency is not the maximum frequency value of the pumps 41 to 61 but an upper limit value set for convenience. The maximum operation excess frequency is set to an operation frequency at which the pumps 41 to 61 do not fail, and is a value larger than the maximum operation frequency. The maximum operation excess frequency is not the maximum frequency value of the pumps 41 to 61 but a second upper limit value set for convenience.

  The twelfth function is a function that, when the number of units is decreased within the monitoring time Z, increases the next limited time limit Z that is set to be longer than the previous value.

  In the thirteenth function, an increase condition is established at the time when the additional time limit elapses, and if an additional number is executed based on the establishment of this condition, the next additional time limit Z is set immediately before This function is shorter than the value.

  In the fourteenth function, if the operating frequency of the pump being operated tends to decrease when the additional time limit Z has elapsed, the additional condition is satisfied when the additional time limit Z has elapsed. This is also a function that limits the number of units.

  Next, changes in the operating frequency of each pump when a plurality of pumps are operated will be described. First, the operation frequency of each pump at the time of adding a base will be described with reference to FIGS. In this description, in order to describe the operating frequency of the pump that is operating, the number of units is increased as soon as the number of units is satisfied without considering the additional stand-by time and the additional time limit.

  FIG. 2 is a graph showing the operating frequency of the pump being operated. FIG. 2 shows a state where only the first pump 41 is driven. The vertical axis | shaft of FIG. 2 has shown the frequency. In the state of FIG. 2, the detection result of the discharge pressure sensor 100 is less than the set pressure value, and the condition for increasing the table is satisfied. For this reason, the microcomputer 111 of the control panel 110 controls the first inverter 43 to increase the operating frequency of the first pump 41.

  FIG. 3 is a graph showing the operating frequency of the first pump 41 in a state in which time has elapsed from the state of FIG. The vertical axis in FIG. 3 is the same as in FIG. In the state of FIG. 3, it has shown that the operating frequency of the 1st pump 41 has reached the maximum operating frequency. Further, in the state of FIG. 3, the detection result of the discharge pressure sensor 100 does not reach the set pressure value. For this reason, the microcomputer 111 of the control panel 110 controls the second inverter 53 to drive the second pump 51. FIG. 3 shows that the operating frequency of the second pump 51 is the lowest operating frequency. The first pump 41 is in a constant speed operation state that is operated at the maximum operation frequency. The second pump 51 is in a variable speed operation state.

  FIG. 4 is a graph showing the operating frequency of the pump operated by the water supply apparatus 10 after a lapse of time from the state of FIG. The vertical axis in FIG. 4 is the same as in FIG. FIG. 4 shows that the operation frequency of the second pump 51 is increased until the detection result of the discharge pressure sensor 100 reaches the set pressure value.

  Next, the frequency of the pump that is operating when the number of units is reduced will be described with reference to FIGS. In this description, in order to describe the operating frequency of the pump that is operating, the reduction waiting time is not taken into consideration, and the number is reduced as soon as the reduction condition is established.

FIG. 5 is a graph showing the operating frequency of the pump being operated. In the state shown in FIG. 5, the first and second pumps 41 and 51 are operating. The vertical axis in FIG. 5 is the same as in FIG. The state of FIG. 5 is a state where the detection result of the discharge pressure sensor 100 exceeds the set pressure value.

  FIG. 6 is a graph showing the operating frequency of the operating pump in a state where time has elapsed from the state of FIG. The graph of FIG. 6 is the same as that of FIG. FIG. 6 shows a state in which the operating frequency of the second pump 51 that is operating at a variable speed is reduced so that the detection result of the discharge pressure sensor 100 becomes the set pressure value. FIG. 6 shows a state where the operating frequency of the second pump 51 has been lowered to the minimum operating frequency. Even in this state, the detection result of the discharge pressure sensor 100 is larger than the set pressure value. FIG. 6 shows a state in which the condition for reducing the table is satisfied. For this reason, the microcomputer 111 of the control panel 110 stops the first pump 41 that is the first pump that is operating first.

  FIG. 7 is a graph showing the operating frequency of the pump that operates in a state in which time has elapsed from the state of FIG. The graph of FIG. 7 is the same as that of FIG. FIG. 7 shows a state where the operation frequency of the first pump 41 whose operation has been stopped is decreasing, and the operation frequency of the second pump 51 so that the detection result of the discharge pressure sensor 100 becomes the set pressure value. Indicates an increased state.

  Next, the stand-by waiting time A and the stand-by waiting time B will be specifically described. For this description, the operation of the water supply apparatus 10 according to the first to seventh functions when the pressure value in the water supply piping system 20 fluctuates instantaneously will be described with reference to FIGS. FIG. 8 is a graph showing a case where the pressure in the water supply piping system 20 is instantaneously increased and the reduction table condition is satisfied. The horizontal axis in FIG. 8 indicates the passage of time, and indicates that the time has passed as it proceeds to the right side in the figure. The vertical axis in FIG. 8 indicates the detection result of the discharge pressure sensor 100, and indicates that the value increases as it proceeds upward in the figure.

  The operating state of the water supply apparatus 10 shown in FIG. 8 will be described. Until the time t1, the first and second pumps 41 and 61 are driven. The first pump 41 performs a constant speed operation, and the second pump 51 performs a variable speed operation.

  At time t1, the detection result of the discharge pressure sensor 100 increases instantaneously. This rise is an example of fluctuation that occurs instantaneously. The microcomputer 111 of the control panel 110 detects that the reduction condition is satisfied at time t1. However, the microcomputer 111 of the control panel 110 limits the reduction until the reduction waiting time B elapses from the time t1. Specifically, the operation of the first pump 41 that is operating first is not stopped. As described above, the pressure fluctuation generated at time t1 is an instantaneous fluctuation. For this reason, at time t2, the detection result of the discharge pressure sensor 100 immediately returns to the set pressure value. Time t2 is smaller than time t1 + decrease stand-by time B.

  At the time t3 when the stand-by waiting time B has elapsed, the detection result of the discharge pressure sensor 100 has returned to the set pressure value, so the stand-off condition is not satisfied. For this reason, the microcomputer 111 of the control panel 110 does not reduce the number at time t3.

  FIG. 9 is a graph showing a case where the pressure in the water supply piping system 20 is instantaneously reduced and the condition for increasing the platform is satisfied. The horizontal and vertical axes in FIG. 9 are the same as those in FIG. The state of the water supply apparatus 10 shown in FIG. 9 will be described. In the state of FIG. 9, the first and second pumps 41 and 51 are driven until time t4. The first pump 41 performs a constant speed operation, and the second pump 51 performs a variable speed operation.

  At time t4, the detection result of the discharge pressure sensor 100 decreases instantaneously. For this reason, the increase condition is established at time t4. However, when the microcomputer 111 of the control panel 110 detects that the increase condition is satisfied at time t4, the microcomputer 111 limits the third pump 61 until the increase standby time A elapses from time t4. Specifically, the third pump 61 is not operated. As described above, the pressure fluctuation generated at time t4 is an instantaneous fluctuation. For this reason, at time t5, the detection result of the discharge pressure sensor 100 returns to the set pressure value. Time t5 is smaller than time t4 + addition stand standby time A.

  At time t6 when the additional stand-by time A elapses, the detection result of the discharge pressure sensor 100 has returned to the set pressure value, so the add-on condition is not satisfied. For this reason, the microcomputer 111 of the control panel 110 does not increase the number of units at time t6.

  As described above, by the first to seventh functions, the microcomputer 111 of the control panel 110, when the increase condition is satisfied, limits the increase until the increase standby time A elapses, and when the decrease condition is satisfied, The number of cars is limited until the waiting time has elapsed. As a result, it is possible to suppress an increase or decrease due to an instantaneous fluctuation of the discharge pressure value.

  Next, operation | movement of a water supply apparatus is demonstrated using FIGS. By having the 8th to 14th functions in addition to the 1st to 7th functions, it is possible to suppress the increase and decrease of the number of operating pumps due to the air layer in the water supply piping system 20. This point will be specifically described. First, the operation of the air layer 28 will be described with reference to FIGS.

  The air layer 28 will be described using the explanation water supply device 500 instead of the water supply device 10 for easy understanding. FIG. 10 is a schematic diagram showing an explanation water supply device 500. As shown in FIG. 10, the explanation water supply apparatus 500 includes an explanation water supply piping system 510, an explanation pump unit 520, an explanation flow switch 530, and an explanation discharge pressure sensor 540.

  The explanation water supply piping system 510 guides water from the water supply side to the explanation faucet 570 on the water receiving side. The explanation pump unit 520 is provided in the vicinity of the water supply side in the explanation water supply piping system 510. The explanation pump unit 520 includes an explanation pump 521 and an explanation drive unit 522.

  The explanatory pump 521 is the same as the pumps 41 to 61. The explanation drive unit 522 is the same as the drive units 42 to 62. The explanation drive unit 522 is connected to an explanation inverter 523 included in the control panel of the explanation pump system 510. The explanation inverter 523 is the same as the inverters 43 to 63. The explanation flow switch 530 is the same as the flow switches 70 to 90. The explanation discharge pressure sensor 540 is the same as the discharge pressure sensor 100.

  An air layer 560 exists in the explanation water supply piping system 510. In the figure, the air layer 560 is hatched for easy understanding. This hatching does not indicate a cross section.

  FIG. 10 shows a state in which time t7 has elapsed since the explanation pump 521 was operated because the discharge pressure value in the explanation feed water piping system 510 became the starting pressure. In FIG. 10, an air layer 560 exists in the range from the first position P <b> 1 of the explanation water supply piping system 510 to the explanation tap 570. In the state of FIG. 10, the explanation tap 570 on the water receiving side is closed.

  FIG. 11 is a schematic diagram illustrating the explanation water supply apparatus 500 in a state in which time t8 has elapsed since the explanation pump 521 was operated because the discharge pressure value in the explanation water supply piping system 510 became the starting pressure. . Time t8 is a state in which time has elapsed from time t7.

  As shown in FIG. 11, the air layer 560 exists in the range from the second position P2 to the explanation faucet 570 in a state where the time t8 has elapsed since the explanation pump 521 started operation. The second position P2 is a position downstream from the first position P1. This is because the pressure in the explanation water supply piping system 510 is increased by operating the explanation pump 521, and the volume of the air layer 560 is reduced due to the increase in the pressure amount. Also in FIG. 11, the explanation tap 570 is closed.

  FIG. 12 is a graph showing the change in discharge pressure over time from the state in which the discharge pressure becomes the starting pressure in the explanation water supply piping system 510 of the explanation water supply apparatus 500. The horizontal axis of FIG. 12 indicates the passage of time, and indicates that the time has passed as it proceeds to the right side in the figure. The vertical axis in FIG. 11 indicates the discharge pressure, and indicates that the discharge pressure increases as it goes upward in the figure.

  As shown in FIG. 12, the discharge pressure starts to rise rapidly at time t9. Time t9 is a time between time t7 and time t8. Time t9 is the time when the volume of the air layer 560 is less likely to become smaller. Since the volume of the air layer 560 is less likely to be reduced, the pressure in the explanatory water supply piping system 510 rapidly increases. As described above, the presence of the air layer 560 may cause the discharge pressure value to rapidly increase.

  Next, the operation of the water supply apparatus 10 will be described. In this description, an increase and decrease in the number of operating pumps with respect to pressure fluctuations and flow rate fluctuations in the water supply piping system 20 caused by the air layer 28 will be described.

  For comparison, first, the operation of the water supply apparatus 10 having only the first to seventh functions will be described. In other words, the operation of the water supply apparatus 10 that does not have the eighth to fourteenth functions will be described. In this description, it is assumed that there is no instantaneous fluctuation in the discharge pressure. In this description, the third pump unit 60 is not used, and only the first and second pump units 40 and 50 are used.

  FIG. 13 shows the operation of the water supply apparatus 10 having only the first to seventh functions among the first to fourteen functions when the discharge pressure varies and the flow rate varies due to the air layer 28 in the water supply piping system 20. It is a graph which shows. Specifically, FIG. 13 shows a change in discharge pressure in the water supply piping system 20 over time, a change in operating frequency of the first pump 41, a detection result of the first flow switch 70, The change of the operating frequency of the 2nd pump 51 and the detection result of the 2nd flow switch 80 are shown.

  In FIG. 13, reference numeral 601 is assigned to a portion indicating a change in discharge pressure in the water supply piping system 20. The horizontal axis of the portion 601 indicates the passage of time, and indicates that the time has passed as it proceeds to the right side in the figure. Reference numeral 601 denotes a detection result of the discharge pressure sensor 100.

  In FIG. 13, reference numeral 602 is assigned to a portion indicating a change in the operating frequency of the first pump 41. The horizontal axis of the portion 602 indicates the passage of time, and indicates that the time has passed as it proceeds to the right side in the figure.

  In FIG. 13, reference numeral 603 is assigned to the portion indicating the detection result of the first flow switch 70. A portion 603 indicates that time has passed as it proceeds to the right in the figure, and a hatched portion indicates that the first flow switch 70 is in an ON state. This hatching does not indicate a cross section.

  In FIG. 13, reference numeral 604 is assigned to a portion indicating a change in the operating frequency of the second pump 51. The horizontal axis of the portion 604 indicates the passage of time and the passage of time as it proceeds to the right side in the figure. The vertical axis of the portion 604 indicates the operating frequency of the second pump 51, and indicates that the frequency increases as it proceeds upward in the figure.

  In FIG. 13, reference numeral 605 is assigned to a portion indicating the detection result of the second flow rate switch 80. A portion 605 indicates that the time has elapsed as it proceeds to the right side in the figure, and a hatched portion indicates that the second flow rate switch 80 is in an ON state. This hatching does not indicate a cross section. In FIG. 13, the time axes of the portions 601 to 605 are synchronized with each other.

  In FIG. 13, the time when the first faucet 1 is opened from the state where all of the first and second faucets 1 and 2 are closed is set to 0. At time 0, the first faucet 1 is opened, so that the pressure in the water supply piping system 20 decreases.

  When the time t10 elapses, the pressure value in the water supply piping system 20 decreases to the starting pressure value. For this reason, the microcomputer 111 of the control panel 110 drives the pump with the lowest operating rate among the pumps 41 to 61 at time t10. In this description, it is assumed that the first pump is the pump with the lowest operating rate. The microcomputer 111 of the control panel 110 controls the first inverter 43 to operate the first pump 41. The microcomputer 111 of the control panel 110 increases the operating frequency of the first pump 41 toward the maximum operating frequency as indicated by a portion 602.

  As the operating frequency of the first pump 41 increases, the discharge pressure value in the feed water piping system 20 increases as indicated by a portion 601. Further, as indicated by a portion 603, the first flow switch 70 is turned on.

  At time t11, as indicated by a portion 602, the operating frequency of the first pump 41 reaches the maximum operating frequency. At time t11, the first flow switch 70 is on. As shown in the portion 601, the discharge pressure value is less than the set pressure. For this reason, the increase condition is established at time t11. However, the microcomputer 111 of the control panel 110 limits the increase of the number of units from the time t11 to the unit standby time A. In addition, the discharge pressure starts to increase after the air layer 28 is compressed by the increase in the discharge pressure and is compressed to the maximum.

  As shown in a part 604, at time t12 when the stand-by time A is increased from time t11, the discharge pressure in the water supply piping system 20 is less than the set pressure. As shown in the portion 603, the first flow switch 70 is in an ON state. For this reason, even after the stand-by time for adding units A has elapsed, the conditions for adding units are maintained.

  For this reason, the microcomputer 111 of the control panel 110 operates the pump having the lowest operation rate among the pumps not operating at time t12. In this description, since only the first and second pumps 41 and 51 can be driven, the microcomputer 111 of the control panel 110 controls the second inverter 53 to operate the second pump 51. In addition, the 1st pump 41 will be in a constant speed operation state by the 2nd pump 51 being drive | operated. The second pump 51 is in a variable speed operation state.

  As shown in the portion 604, the operating frequency of the second pump 51 increases toward the maximum operating frequency after time t12. As shown in the portion 601, the pressure in the feed water piping system 20 increases. As shown in the portion 605, the second flow rate switch 80 is turned on.

  As shown in a part 601, at time t13, the pressure in the water supply piping system 20 reaches the set pressure value. At time t13, as shown in the portion 604, the operating frequency of the second pump 51 is less than the maximum operating frequency. For this reason, the reduction condition is satisfied at time t13. It is the first pump 41 that is operating first that is subject to the reduction.

  The microcomputer 111 of the control panel 110 limits the reduction until the reduction standby time B elapses from the time t13 when the reduction condition is satisfied. The microcomputer 111 of the control panel 110 decreases the pressure in the feed water piping system 20 by decreasing the operating frequency of the second pump 51 after time t13.

  The increase in the discharge pressure in the vicinity of the time t13 is a pressure increase caused by the air layer 28 of the water supply piping system 20. This rise is caused by the air layer 28. As described with reference to FIGS. 10 to 12, due to the air layer 28, the discharge pressure in the water supply piping system 20 rapidly increases. Note that the method of increasing the discharge pressure is different from the graph shown in FIG. This is because of the difference in structure between the explanation water supply device 500 and the water supply device 10.

  For this reason, after time t13, even if the operating frequency of the second pump 51 is decreased, the discharge pressure in the feed water piping system 20 continues to rise.

  Even at time t14 when the stand-by waiting time B has elapsed from time t13, the discharge pressure in the water supply piping system 20 is greater than the set pressure value. Therefore, the microcomputer 111 of the control panel 110 determines that the reduction condition is satisfied even after the reduction waiting time B has elapsed, and the first pump 41 is stopped to stop the operation. The inverter 43 is controlled to reduce the operating frequency of the first pump 41 until it becomes zero.

  The microcomputer 111 of the control panel 110 does not decrease the operation frequency abruptly but relatively slowly until the operation frequency of the first pump 41 reaches the reduced frequency. This is to match the change in the operating frequency of the pump being operated. This point will be specifically described.

  As described above, when the number of pumps operating at a constant speed is reduced from the state in which a plurality of pumps are operating, the pressure in the water supply piping system 20 is rapidly reduced. For this reason, the microcomputer 111 of the control panel 110 increases the operating frequency of the pump being operated in order to prevent the discharge pressure from rapidly decreasing. The reduction frequency is set in order to wait for the operating frequency of the operating pump to increase.

  Returning to the description of FIG. At time t15, the operating frequency of the first pump 41 decreases to the reduced frequency. At time t15, the discharge pressure decreases to the set pressure value. Furthermore, after time t15, the discharge pressure continues to decrease.

  After time t15, the operating frequency of the first pump 41 is rapidly decreased. Along with this, as shown in the portion 601, the discharge pressure decreases to less than the starting pressure. For this reason, the microcomputer 111 of the control panel 110 increases the operating frequency of the second pump 51 at time t15.

  At time t16, the operating frequency of the second pump 51 becomes the maximum operating frequency. However, as shown in portion 601, the discharge pressure is less than the starting pressure value. As shown in portion 605, second flow switch 80 is in an on state. For this reason, at time t16, the condition for increasing the number is satisfied.

  However, the microcomputer 111 of the control panel 110 limits the number of units to be increased during the time t16 from the time t16. At time t17 when the additional stand-by time A has elapsed, the operating frequency of the second pump 51 is the maximum operating frequency, the second flow rate switch 80 is in the ON state, and the discharge pressure is less than the set pressure value. . For this reason, at time t17, the condition for increasing the number is satisfied. The microcomputer 111 of the control panel 110 drives the first pump 41 at time t17. The second pump 51 is in a constant speed operation state, and the first pump 41 is in a variable speed operation state.

  As shown in a portion 601, at time t18, the discharge pressure reaches the set pressure value. As shown in part 602, at time t18, the operating frequency of the first pump 41 is less than the maximum operating frequency, and as shown in part 603, the first flow switch 70 is in the ON state. For this reason, at time t18, the reduction condition is established.

  At time t19 when the stand-by waiting time B elapses from time t18, as indicated by a portion 604, the operating frequency of the second pump 51 is the maximum operating frequency. As shown in the portion 601, the discharge pressure is larger than the set pressure. As shown in portion 605, the second flow switch 80 is in an on state. For this reason, at time t19, since the reduction condition is established, the second pump 51 is reduced.

  As shown in the part 601, due to the volume change of the air layer 28, the discharge pressure is maintained at a value larger than the set pressure value as shown in the part 601 after the time t19. For this reason, the microcomputer 111 of the control panel 110 gradually reduces the operating frequency of the second pump 51 to be reduced to the reduced frequency, and the operating frequency of the first pump 41 that is performing variable speed operation. Decrease.

  As shown in a portion 601, the discharge pressure starts to decrease after time t19 and then reaches a set pressure value at time t20. The discharge pressure continues to decrease after time t20. For this reason, the microcomputer 111 of the control panel 110 increases the operating frequency of the first pump 41 by controlling the first inverter 43 performing the variable side operation at time t20.

  Thereafter, as shown in a portion 601, the discharge pressure starts increasing at time t21. At time t22, as shown in the portion 602, the operating frequency of the first pump 41 reaches the maximum operating frequency. As shown in the portion 601, at time t22, the discharge pressure is less than the set pressure value. As shown in the portion 603, at the time t22, the first flow switch 70 is in the ON state. For this reason, the microcomputer 111 of the control panel 110 determines that the increase condition is satisfied at time t22.

  However, the microcomputer 111 of the control panel 110 restricts the operation of the second pump 51 from the time t22 to the stand-by time for adding the station A. As shown in a portion 601, at time t23 when the stand-by time A for the additional base has elapsed from time t22, the discharge pressure is less than the set pressure value. As shown in the portion 602, at the time t23, the operating frequency of the first pump 41 is the maximum operating frequency. As shown in the portion 603, at the time t23, the first flow switch 70 is in the ON state. For this reason, at time t23, the condition for increasing the number is satisfied.

  The microcomputer 111 of the control panel 110 controls the second inverter 53 to operate the second pump 51 at time t23. Thereafter, the operating frequency of the second pump 51 increases. Thereafter, at time t24, as shown in a portion 601, the discharge pressure reaches a set pressure value. At this time, as indicated by a portion 604, the operating frequency of the second pump 51 is less than the maximum operating frequency. As shown in portion 605, the second flow switch 80 is in an on state. For this reason, at time t24, the condition for reduction is satisfied.

  However, the microcomputer 111 of the control panel 110 limits the reduction of the first pump 41 until the reduction waiting time B elapses from the time t24. The microcomputer 111 of the control panel 110 decreases the operating frequency of the second pump 51 performing variable speed operation.

  Thereafter, at the time t25 when the stand-by waiting time B has elapsed, the discharge pressure exceeds the set pressure value as indicated by a portion 601. As shown in portion 604, the operating frequency of the second pump 51 is less than the maximum operating frequency. As shown in portion 605, the second flow switch 80 is in an off state. For this reason, at time t <b> 25, the reduction condition is satisfied. The microcomputer 111 of the control panel 110 reduces the first pump 41 after time t25.

  Thereafter, as indicated by a portion 601, the discharge pressure exceeds the set pressure value. For this reason, the microcomputer 111 of the control panel 110 decreases the operating frequency of the second pump 51 performing variable speed operation. Thereafter, at time t26, due to the volume change of the air layer 28, the discharge pressure starts to increase as indicated by a portion 601. However, since the discharge pressure is less than the set pressure value, the microcomputer 111 of the control panel 110 continues to increase the operating frequency of the second pump 51.

  Thereafter, at time t27, as indicated by a portion 604, the operating frequency of the second pump 51 reaches the maximum operating frequency. Further, as indicated by a portion 601, the discharge pressure is less than the set pressure value. Moreover, as shown in the part 605, the 2nd flow switch 80 is an ON state. For this reason, at time t27, the condition for increasing the number is satisfied.

  However, the microcomputer 111 of the control panel 110 limits the increase in the number of first pumps 41 from the time t <b> 27 to the increase stand-by time A. After that, at time t28 when the additional stand-by time A elapses, as indicated by a portion 601, the discharge pressure is less than the set pressure value. As indicated by a portion 604, the operating frequency of the second pump 51 performing variable speed operation is the maximum operating frequency. As shown in a portion 605, the second flow rate switch 80 performing the variable speed operation is in an ON state.

  As described above, due to the presence of the air layer 28 in the water supply piping system 20, the water supply device 10 first increased the number of units at time t <b> 14, thereby causing the air layer in the water supply piping system 20 to Volume changes greatly. Due to this volume change, after time t13, as indicated by a portion 601, the discharge pressure repeatedly increases and decreases across the set pressure value and does not converge to the set pressure value.

  Next, the operation of the water supply apparatus 10 will be described. In this description, the water supply apparatus 10 has first to fourteenth functions. FIG. 14 is a graph showing the operation of the water supply apparatus 10 having the first to fourteenth functions. In the graph shown in FIG. 14, the portions 601 to 605 indicate the same as in FIG. 13. For this reason, in FIG. 14, the description of the same part as in FIG. 13 is simplified.

  First, when the first faucet 1 is opened at time 0, the discharge pressure of the water supply piping system 20 is lowered as shown by a portion 601. Thereafter, at time t10, the discharge pressure decreases to the starting pressure value. For this reason, the microcomputer 111 of the control panel 110 controls the first inverter 43 in order to operate the first pump 41 at time t10. Thereafter, as shown in the portion 602, the operating frequency of the first pump 41 increases toward the maximum operating frequency. Further, as indicated by a portion 601, the discharge pressure increases.

  After that, when the time t11 is reached, the condition for increasing the platform is satisfied. The microcomputer 111 of the control panel 110 controls the second inverter 53 in order to operate the second pump 51 at time t12.

  Further, the microcomputer 111 of the control panel 110 starts measuring the time from when the number of units is increased at time t12 until the next time the number of units is decreased. This measurement time is defined as measurement time Y. Here, the measurement time Y will be specifically described.

  In the present embodiment, the start of the increase is that the operation of the pump is controlled by controlling the inverter of the pump to be increased. That is, as shown at time t12 in FIG. 14, it is a time when the operating frequency of the second pump 51 starts to rise. In this embodiment, if the reduction condition is maintained when the reduction standby time B has elapsed, the microcomputer 111 of the control panel 110 controls the inverter of the pump to be reduced and reduces it from the maximum operating frequency. Lower to table frequency. The operating frequency is controlled by the microcomputer 111 of the control panel 110 during the period from the maximum operating frequency to the reduced frequency. When the operating frequency falls to the reduced frequency, the microcomputer 111 of the control panel 110 stops controlling the inverter so that the operating frequency becomes zero. For this reason, in the present embodiment, as described above, until the reduction is completed, the reduction frequency is reached. For this reason, in this embodiment, the measurement time Y is from the time when the operation frequency of the pump to be increased starts to the time when the operation frequency of the pump to be decreased next reaches the decrease frequency. Is the time.

  Thereafter, at time t13, the reduction condition is satisfied. The microcomputer 111 of the control panel 110 controls the first inverter 43 to reduce the number of the first pump 41 at the time t14 when the reduction waiting time B elapses. Thereafter, the first pump 41 gradually decreases to the reduced frequency under the control of the microcomputer 111 of the control panel 110, and reaches the reduced frequency at time t15.

  The microcomputer 111 of the control panel 110 stops measuring the time when the time t15 is reached, that is, when the operating frequency of the first pump 41 to be reduced reaches the reduced frequency. That is, the measurement time Y is from time t12 to time t15.

  The microcomputer 111 of the control panel 110 compares the measurement time Y with the monitoring time X. In this description, the measurement time Y is less than the monitoring time X. For this reason, the microcomputer 111 of the control panel 110 continues to this stand-by time when the stand-up condition is maintained and the stand-up condition is maintained after the stand-by time A has elapsed. To set the additional time limit Z.

  The additional time limit Z is set for the time when the measurement time Y is less than the monitoring time X, the additional condition is satisfied, and the additional standby time A is After the elapse of time, it is only once when the condition for adding the platform is maintained. Once the measurement time Y becomes less than the monitoring time X, the subsequent condition for adding the platform is satisfied, and the waiting time for adding the platform A has elapsed. After that, if the condition for increasing the number is maintained, the additional time limit Z is not set for all. That is, the additional time limit Z is set every time the measurement time Y becomes less than the monitoring time X.

  Thereafter, at time t16, the condition for increasing the number of vehicles is satisfied. Since the additional condition is maintained even at time t17 when the additional stand-by time A elapses, the microcomputer 111 of the control panel 110 sets the additional limit time Z as described above. The microcomputer 111 of the control panel 110 limits the number of units to be increased during the time limit Z for adding units.

  After that, the conditions for increasing the number of cars have been met. That is, the discharge pressure is less than the set pressure value, the operating frequency of the second pump 51 is the maximum operating frequency, and the second flow rate switch 80 is in the ON state.

  For this reason, the microcomputer 111 of the control panel 110 raises the upper limit value of the operating frequency of the pump being operated to the maximum operating excess operating frequency. As a result, the operation frequency of the second pump 51 can be increased to the maximum operation excess frequency. The microcomputer 111 of the control panel 110 increases the operation frequency of the second pump 51 toward the maximum operation excess frequency so that the discharge pressure becomes the set pressure value.

  FIG. 15 is a graph showing the relationship between the water supply amount and the discharge pressure of the water supply apparatus 10. The horizontal axis of FIG. 15 indicates the amount of water supply, and indicates that the amount of water supply increases as it proceeds to the right side in the figure. The vertical axis in FIG. 15 indicates the discharge pressure, and indicates that the pressure increases as it goes upward in the figure.

  A curve C1 in FIG. 15 shows a relationship between the water supply amount and the discharge pressure in a state where any one of the pumps 41 to 61 is operating. In FIG. 15, a curve C2 indicates the relationship between the water supply amount and the discharge pressure when any two of the pumps 41 to 61 are operating.

  FIG. 15 also shows a curve C3 indicating the characteristics when this pump is operated at the maximum overrun frequency when only one pump is operating. Note that hatching is applied to a portion between a curve C1 indicating the characteristics when the one pump is operated at the maximum operation frequency and a curve C3 indicating the characteristics when the one pump is operated at the maximum operation excess frequency. This hatching does not indicate a cross section. As shown in FIG. 15, it can be seen that the amount of water supplied by the operation of one pump increases when the operating frequency of the pump reaches the maximum operating excess frequency.

  FIG. 16 is a graph showing the frequency of the pump operating in the water supply apparatus 10. FIG. 16 is the same as FIGS. 2 to 4 and shows the frequency of the pump at the time t17 shown in FIG. FIG. 16 shows a state where the first pump 41 is operating at the maximum operation excess frequency. Note that hatching is applied to the range exceeding the maximum operating frequency. This hatching does not indicate a cross section.

  As shown in FIG. 15, when one pump is operated at the maximum overrun frequency and when two pumps are operated, the amount of water supply is larger when the two pumps are operated. This indicates that the rate of increase in pressure in the feed water piping system 20 is larger when two pumps are operated than when one pump is operated at the maximum operation excess frequency.

  For this reason, as shown in FIGS. 13 and 14, the rate of increase in the discharge pressure is smaller when one pump is operated at the maximum overrun frequency. Since the rate of increase is small, after time t17, the slope of the line representing the characteristic shown in the portion 601 in FIG. 14 is smaller than the slope of the line representing the characteristic shown in the portion 601 in FIG.

  Thereafter, at time t30, the discharge pressure reaches the set pressure value. From time t30 to time t31, the discharge pressure is maintained at the set pressure value. This is because the discharge pressure decreases due to the end of the increase in discharge pressure due to the air layer 28 in the water supply piping system 20 and the discharge pressure increases due to the first pump 41 operating at the maximum overrun frequency. This is because they are mutually offset.

  Thereafter, at time t31, the degree of decrease in the discharge pressure due to the air layer 28 in the feed water piping system 20 increases, and therefore the discharge pressure in the feed water piping system 20 starts to drop below the set pressure value. . As a result, the condition for increasing the number is established. However, the time t31 is within the additional platform limit time Z. For this reason, the microcomputer 111 of the control panel 110 limits the number of units.

  Thereafter, when the time t32 comes, the additional time limit time Z ends. Even at time t32, the discharge pressure in the water supply piping system 20 remains lower than the set pressure value. For this reason, at the time of time t32, the condition for increasing the number of tables is maintained. The microcomputer 111 of the control panel 110 starts the operation of the first pump 41 to increase the number of pumps at time t32.

  Next, the operating frequency of the pump that is operating within the additional time limit time Z starts decreasing, and the operating frequency of the pump that is operating even at the end of the additional time limit time Z is decreasing, and A case where the condition for adding the vehicle is satisfied at the end of the additional vehicle time limit Z will be described with reference to FIG. FIG. 17 is a graph showing the operation of the water supply apparatus 10.

  Since the parts shown in FIG. 17 are the same as those shown in FIG. 14, the reference numerals 601 to 605 are given to the parts as in FIG. FIG. 17 is the same as FIG. 14 until time t17. For this reason, the description up to time t17 is omitted. In FIG. 17, when it becomes time t33 within the additional base time limit Z, the discharge pressure exceeds the set pressure value. For this reason, the microcomputer 111 of the control panel 110 decelerates the operation frequency of the second pump 51 from the maximum operation excess frequency at time t33. For this reason, at time t34, the discharge pressure starts to decrease. The time t34 is after the time t33 and is less than the time t32 at which the extension limit time Z ends.

  The discharge pressure decreases to the set pressure at a time point before time t32 when the increase limit time Z ends, and becomes less than the set pressure at time t32. For this reason, the microcomputer 111 of the control panel 110 also sets the operating frequency of the second pump 51, which is the operating pump, to a value higher than the maximum operating frequency even at the time t32 when the increase limit time Z ends. So that it is controlled.

  In this description, the microcomputer 111 of the control panel 110 continues the deceleration of the operating frequency of the second pump 51 based on the discharge pressure until the time t35 that exceeds the time t32 when the limit time for increasing the number of base stations ends. The operating frequency of the second pump 51 becomes the maximum operating frequency at time t35. That is, the operation frequency of the second pump 51 starts to decrease from the maximum operation excess frequency at time t33, and reaches the maximum operation frequency at time t35.

  The operating frequency of the second pump 51 continues to decrease at the time t32 when the increase limit time Z ends. That is, the operating frequency of the second pump 51 tends to decrease at time t32. At time t32 when the additional base limit time Z ends, the discharge pressure decreases to a value smaller than the set pressure.

  For this reason, at time t32 when the additional time limit time Z ends, the additional condition is satisfied. However, the microcomputer 111 of the control panel 110 limits the number of units to be increased because the operating frequency of the second pump 51 that is operating tends to decrease at the time t32 when the number of units to be added limited time Z ends. The microcomputer 111 of the control panel 110 responds to a decrease in discharge pressure by setting the operating frequency of the second pump 51 to a value higher than the maximum operating frequency even at time t32. As a result, at time t36, the discharge pressure rises to the set pressure value and then maintains the set pressure value. Time t36 is a state in which time has elapsed with respect to time t35.

  As described above, in this embodiment, the measurement time Y and the monitoring time X are compared, and the additional time limit Z is set based on the comparison result, thereby causing the air layer 28 as shown in FIG. It can suppress that the increase / decrease of the discharge pressure to generate | occur | produce is repeated. As a result, it is possible to suppress the occurrence of increase / decrease in the number of operating pumps due to the increase / decrease.

  In addition, when the number of units is increased based on the state at the time when the additional time limit Z has elapsed, the microcomputer 111 of the control panel 110 immediately sets this additional time limit Z when the next additional time limit Z is set. Shorter than the value of. This point will be specifically described.

  Even if the microcomputer 111 of the control panel 110 determines that the operating state of the water supply device 10 is affected by the air layer 28, the number of units can be increased based on the state when the additional time limit Z has elapsed. In other words, if the expansion condition is satisfied and the expansion is performed, the increase condition is not caused by the air layer 28, and the amount of water received from the first and second faucets 1 and 2 is increased. May accompany. This is because if the discharge pressure varies due to the air layer 28, the variation often falls within the additional time limit Z.

  For this reason, by shortening the additional time limit Z with respect to the previous value, it is possible to quickly respond to the establishment of the additional condition accompanying the increase in the amount of water received from the first and second faucets 1 and 2. become. The shortening time is determined in advance. Alternatively, for example, as an example of shortening the additional time limit with respect to the previous value, the additional time limit Z may be returned to the initial value. The initial value is a predetermined value.

  Further, whenever the microcomputer 111 of the control panel 110 determines that the measurement time Y is shorter than the monitoring time X, that is, to set the additional time limit Z, the additional time limit Z is set to the immediately preceding value. Make it longer. This indicates that the discharge pressure due to the air layer 28 is frequently increased or decreased. Therefore, by increasing the extension limit time Z, it is possible to limit the increase until the frequent fluctuation of the discharge pressure caused by the air layer 28 is settled.

  In this way, whenever the additional number of times is increased, the additional time limit Z is shortened every time the additional number of times is executed, and each time the setting of the additional time limit Z is determined, the additional time limit By repeating the operation of lengthening Z, the additional time limit time Z becomes a length according to the operating state of the water supply apparatus 10. As a result, the additional base time limit Z changes to a value according to the operating state of the water supply apparatus 10, and therefore it is possible to suppress the repeated increase / decrease of the operating pump.

  Even if the expansion condition is satisfied at the end of the additional time limit Z, if the operating frequency of the pump operating at the end of the additional time limit is decreasing, the increase is limited. In other words, the number of units is not increased.

  In this way, even if the increase condition is satisfied, if the operating frequency of the operating pump is decreasing, the discharge pressure can be adjusted by adjusting the operating frequency of the operating pump. is there. For this reason, since it is possible to prevent an increase in the number of units, it is possible to prevent the consumption of power and the occurrence of fluctuations in the discharge pressure due to the increase in the number of units.

  Further, as described above, in the present embodiment, the operating frequency of the pump to be operated is performed by feeding back the detection result of the discharge pressure sensor 100. For this reason, a response delay occurs in the control of the operating frequency of the operating pump. However, by setting the additional base time limit Z and setting the maximum overrun frequency, it is possible to prevent the pump from increasing or decreasing due to the response delay described above, so that the discharge pressure value can be stabilized. it can.

  In the first and second embodiments, the water supply piping system 20 is an example of a flow path section referred to in the present invention. The flow rate switches 70 to 90 are examples of the flow rate detection unit referred to in the present invention. The flow rate switches 70 to 90 are turned on when a predetermined flow rate is reached, and can detect the predetermined flow rate. As another example, a flow rate detector that can detect the flow rate of water discharged from the pump may be used. The discharge pressure sensor 100 is an example of a pressure detection unit referred to in the present invention. The microcomputer 111 of the control panel 110 is an example of a control unit referred to in the present invention. Further, the microcomputer 111 of the control panel 110 also has a function as an operation frequency detection unit referred to in the present invention. As another example, an operating frequency detector that detects the operating frequency of each pump may be used separately from the microcomputer 111 of the control panel 110.

  In the present embodiment, the first, second, and third flow switches 70, 80, 90 are turned on when the flow rate is equal to or higher than the predetermined flow rate, and are turned off when the flow rate is less than the predetermined flow rate. In another example, the first, second, and third flow switches 70, 80, and 90 may be configured to be in an off state when the flow rate is equal to or higher than a predetermined flow rate and to be in an on state when the flow rate is less than the predetermined flow rate.

  In this case, when the microcomputer 111 of the control panel 110 receives signals from the first, second, and third flow switches 70, 80, and 90, the microcomputer 111 determines that the flow is less than the predetermined flow, and the first, second, and third flow switches 70. , 80, 90 in a state where signals are not received, it is determined that the flow rate is equal to or higher than the predetermined flow rate.

  Therefore, the microcomputer 111 of the control panel 110 has, as a second function, the discharge pressure detection result is less than the set pressure value, the operating frequency of the pump that is variably operating is the maximum operating frequency, and the variable speed operating state is If the flow rate water switch provided downstream of the pump is in the OFF state, it is determined that the condition for adding the base is satisfied. Similarly, the microcomputer 111 of the control panel 110 has, as a third function, the result of the discharge pressure sensor 100 is larger than the set pressure value, the operation frequency of the pump in the variable operation state is less than the maximum operation frequency, and the variable speed operation state is If the flow rate water switch provided downstream of the pump is in the ON state, it is determined that the reduction table condition is satisfied. In this case, in the portions 603 and 605 of FIGS. 13 and 14, the hatched portions indicate the OFF state of the flow rate switch.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, you may delete some components from all the components shown by embodiment mentioned above.
The invention described in the initial claims of the present application will be appended below.
[1]
Multiple pumps,
An operating frequency adjusting unit provided in each of the plurality of pumps, and capable of adjusting an operating frequency of the provided pump;
A flow path section for guiding the liquid discharged from the plurality of pumps to the receiving side;
A control unit for controlling operations of the plurality of pumps;
Comprising
The operating frequency adjustment unit includes a drive unit that drives the pump, and an inverter that can adjust the frequency of power supplied to the drive unit,
The controller is
The inverter can be controlled;
When an increase condition for increasing the number of pumps to be operated is satisfied, the increase is limited during the preset standby time after the increase condition is satisfied,
When the reduction condition for reducing the number of pumps operated is established, the reduction is limited during the reduction waiting time set in advance after the reduction condition is established,
When the number of operating units is reduced within a preset monitoring time from the time when the number of operating pumps is increased by one, the number of operating units continues in succession to the next waiting time for increasing units. Set an additional time limit to limit the number of additional cars
The liquid supply apparatus characterized by the above-mentioned.
[2]
A flow rate detector capable of detecting at least a predetermined flow rate of each of the plurality of pumps;
An operating frequency detector for detecting the operating frequency of each pump;
A pressure detection unit for detecting the pressure in the flow path unit;
Comprising
The controller is
Based on the detection results of the flow rate detection unit, the operation frequency detection unit, and the pressure detection unit, it is determined whether the increase condition and the decrease condition are satisfied.
The liquid supply apparatus according to Supplementary Note [1], wherein:
[3]
The control unit operates when the operating frequency of the pump being operated is the first upper limit value and the pressure in the flow path unit is smaller than a predetermined value within the time limit for increasing the platform. The inverter that drives the operating pump is controlled so that the operating pump is operated at a frequency in a range from the first upper limit value to the second upper limit value.
The liquid supply apparatus according to [1] or [2], which is characterized by the above.
[4]
When the number of units is decreased within the monitoring time after the number of units is increased, the control unit sets a time limit for increasing the number of units to be set longer than the previous value.
The liquid supply apparatus according to any one of supplementary notes [1] to [3], wherein:
[5]
The control unit establishes an additional condition when the additional time limit elapses, and when an additional number is executed on the basis of the additional condition, the next additional time limit is set. , Shorter than the previous value
The liquid supply apparatus according to any one of supplementary notes [1] to [4], wherein:
[6]
The control unit, when the increase condition is satisfied at the time when the additional time limit elapses, even if the operating frequency of the pump that is operating at the time when the additional time limit has elapsed is decreasing , Limit the increase
The liquid supply apparatus according to any one of supplementary notes [2] to [5], wherein:

DESCRIPTION OF SYMBOLS 10 ... Water supply apparatus (liquid supply apparatus), 20 ... Water supply piping system (flow-path part), 41 ... 1st pump (pump), 42 ... 1st drive part (drive part), 43 ... 1st inverter ( Inverter), 51 ... Second pump (pump), 52 ... Second drive unit (drive unit), 53 ... Second inverter (inverter), 61 ... Third pump (pump), 62 ... Third Drive unit (drive unit), 63 ... third inverter (inverter), 70 ... first flow rate switch (flow rate detection unit), 80 ... second flow rate switch (flow rate detection unit), 90 ... third flow rate switch (Flow rate detection unit), 100... Discharge pressure sensor (pressure detection unit), 110... Control panel (control unit, operation frequency detection unit).

Claims (6)

Multiple pumps,
An operating frequency adjusting unit provided in each of the plurality of pumps, and capable of adjusting an operating frequency of the provided pump;
A flow path section for guiding the liquid discharged from the plurality of pumps to the receiving side;
A controller that controls the operation of the plurality of pumps,
The operating frequency adjustment unit includes a drive unit that drives the pump, and an inverter that can adjust the frequency of power supplied to the drive unit,
The controller is
The inverter can be controlled;
When an increase condition for increasing the number of pumps to be operated is satisfied, the increase is limited during the preset standby time after the increase condition is satisfied,
When the reduction condition for reducing the number of pumps operated is established, the reduction is limited during the reduction waiting time set in advance after the reduction condition is established,
When the number of operating units is reduced within a preset monitoring time from the time when the number of operating pumps is increased by one, the number of operating units continues in succession to the next waiting time for increasing units. A liquid supply device, characterized in that a time limit for increasing the number of stations is set to limit the number of additional stations. A flow rate detector capable of detecting at least a predetermined flow rate of each of the plurality of pumps;
An operating frequency detector for detecting the operating frequency of each pump;
A pressure detection unit for detecting the pressure in the flow path unit,
The controller is
The establishment of the increase condition and the establishment of the decrease condition are determined based on detection results of the flow rate detection unit, the operation frequency detection unit, and the pressure detection unit. Liquid supply apparatus of description. Wherein, in the increase of base within a time limit, the operation to which the operating frequency of the pump the first upper limit der is, and, when the pressure in the channel portion is smaller than a predetermined value, the flow path The operating pump is driven so that the operating pump is operated at a frequency ranging from the first upper limit value to the second upper limit value so that the internal pressure becomes the predetermined value. The liquid supply apparatus according to claim 1, wherein the inverter is controlled. 4. The control unit according to claim 1, wherein if the number of units is decreased within the monitoring time after the number of units is increased, the time limit for increasing units to be set next is made longer than the immediately preceding value. 2. The liquid supply apparatus according to item 1. The control unit establishes an additional condition when the additional time limit elapses, and when an additional number is executed on the basis of the additional condition, the next additional time limit is set. The liquid supply device according to claim 1, wherein the liquid supply device is shorter than the immediately preceding value. The control unit, when the increase condition is satisfied at the time when the additional time limit elapses, even if the operating frequency of the pump that is operating at the time when the additional time limit has elapsed is decreasing The liquid supply device according to any one of claims 2 to 5, wherein the number of units is limited.