Control system and control system switching method for water treatment system

Abstract

To reduce pressure fluctuations that occur when a control system with a redundant configuration is switched.SOLUTION: The control system has: a control valve 110 which adjusts the pressure of liquid flowing through a passage; a switching unit 130 which outputs a control signal output from the control system to the control valve 110; pressure gauges 121-1 and 121-2 which measure the water pressure of the liquid flowing through the passage; and control signal generators 122-1 and 122-2 which generate a control signal based on the measured values measured by the pressure gauges 121-1 and 121-2 of the system and output the control signal to the switching unit 130 when the system is a control system. When the system is a standby system, the control signal generators 122-1 and 122-2 output the control signal output from the control system to the switching unit 130, and when the system is switched from the standby system to the control system, the control signal generators generate the control signal based on the measured values measured by the pressure gauges 121-1 and 121-2 of the system as an initial value which is a value of the control signal output before the switching, and output the control signal to the switching unit 130.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control system and a control system switching method for a water treatment system. [Background technology]

[0002] In a water treatment system equipped with a water treatment device, a technology has been devised in which treated water is circulated for reuse (see, for example, Patent Document 1). In such a water treatment system, the pressure of the circulated water is controlled using a pressure regulating valve. The pressure of the circulated water is controlled using a pressure gauge, which is a sensor that measures pressure, and a regulator that controls the opening of the pressure regulating valve based on the measured pressure value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2018-030087 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned technology uses only one combination of pressure gauge and regulator, so if these instruments fail or require maintenance, the water treatment system must be shut down, affecting the user. In recent years, a technology has been adopted that provides two systems consisting of the above combination, operating one as a control system and the other as a standby system, and switching between the control systems. However, switching between the two systems can cause fluctuations in the output signal to the pressure regulator valve, potentially resulting in sudden pressure fluctuations.

[0005] An object of the present invention is to provide a control system and a control system switching method for a water treatment system that can reduce pressure fluctuations that occur when switching a control system having a redundant configuration in a water treatment system. [Means for solving the problem]

[0006] The control system of the present invention comprises: a regulator valve for regulating the pressure of a liquid flowing through a flow path of the water treatment system; Two systems, one being a control system and the other being a standby system, which operate mutually exclusively; a switching unit that outputs a control signal that controls the opening degree of the regulator valve, the control signal being output from the control system, to the regulator valve; Each of the two systems is a pressure gauge located upstream of the regulating valve for measuring the water pressure of the liquid flowing through the flow path; When the system is the control system, a control signal generating unit generates the control signal based on a measurement value measured by the pressure gauge included in the system and outputs the generated control signal to the switching unit; an inter-system output unit that outputs the control signal generated by the control signal generation unit of the control system to the control signal generation unit of the standby system, When the system is the standby system, the control signal generating unit outputs the control signal output from the inter-system output unit of the system that is the control system to the switching unit, and when the system is switched from the standby system to the control system, the control signal generating unit generates the control signal based on the measurement value measured by the pressure gauge of the system, using the value of the control signal output before the switching as the initial value, and outputs the generated control signal to the switching unit.

[0007] Further, the control system switching method for a water treatment system of the present invention includes: A control system switching method for a water treatment system having two systems, one of a control system and a standby system, which operate mutually exclusively, comprising: a process in which a pressure gauge provided in each of the two systems measures the water pressure of the liquid upstream of a control valve that adjusts the pressure of the liquid flowing through a flow path of the water treatment system; A process in which the control system generates a control signal for controlling the opening degree of the regulator valve based on the measured value; a process in which the control system outputs the generated control signal to the standby system; a process in which the control system outputs the generated control signal to the regulator valve; When the standby system is switched to the control system, the value of the control signal output from the control system before the switch is set as the initial value, and the control signal is generated based on the measurement value measured by the pressure gauge of that system, and the generated control signal is output to the control valve. [Effects of the Invention]

[0008] In the present invention, it is possible to reduce pressure fluctuations that occur when switching control systems having redundant configurations in a water treatment system. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing an example of a water treatment system to which a first embodiment of a control system of the present invention is applied. [Figure 2] FIG. 2 is a diagram illustrating an example of a specific configuration of a control system according to the first embodiment. [Figure 3] 3 is a sequence diagram for explaining an example of a control system switching method in the control system shown in FIG. 2. FIG. [Figure 4] FIG. 10 is a diagram illustrating an example of a specific configuration of a control system according to a second embodiment. [Figure 5] 5 is a sequence diagram illustrating an example of a control system switching method in the control system shown in FIG. 4. FIG. [Figure 6] FIG. 10 is a diagram illustrating an example of a specific configuration of a control system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (First embodiment)

[0011] FIG. 1 is a diagram showing an example of a water treatment system to which a first embodiment of the control system of the present invention is applied. As shown in FIG. 1, a control system 100 in this embodiment is provided in a water treatment system that supplies liquid stored in a water tank 200 to a point-of-use 400 using a pump 300. The point-of-use 400 is a point where, for example, semiconductor devices are cleaned using ultrapure water supplied from the water tank 200. The water tank 200 stores a liquid to be used at the point-of-use 400. The pump 300 pumps the liquid stored in the water tank 200 and supplies it to the point-of-use 400. The liquid supplied to the point-of-use 400 is returned to the water tank 200 via the control system 100. In other words, the flow path that returns the liquid from the water tank 200 to the water tank 200 is a circulation flow path that passes through the point-of-use 400 and the control system 100. Although not shown in FIG. 1, one or more water treatment devices may be provided between the water tank 200 and the point-of-use 400. The control system 100 controls the pressure of the liquid flowing through the flow path.

[0012] Fig. 2 is a diagram showing an example of a specific configuration of the control system 100 in the first embodiment. As shown in Fig. 2, the control system 100 in the first embodiment has a regulator valve 110, systems 120-1 and 120-2, and a switching unit 130. Note that Fig. 2 shows only the main components related to this embodiment among the components of the control system 100 shown in Fig. 1.

[0013] The regulator valve 110 regulates the pressure of the liquid flowing through the flow path of the water treatment system shown in Fig. 1. Specifically, the regulator valve 110 is a valve that adjusts the degree of opening based on external control.

[0014] The two systems 120-1 and 120-2 are systems that operate in mutually exclusive operating states: a control system that performs operation (control) and a standby system that stands by. When one of the systems 120-1 and 120-2 operates as a control system, the other operates as a standby system.

[0015] The system 120-1 includes a pressure gauge 121-1, a control signal generator 122-1, an inter-system output unit 123-1, and a fault detector 125-1. The system 120-2 includes a pressure gauge 121-2, a control signal generator 122-2, an inter-system output unit 123-2, and a fault detector 125-2.

[0016] Each of the pressure gauges 121-1 and 121-2 is located upstream of the control valve 110 and measures the water pressure of the liquid flowing in the flow path.

[0017] Each of the control signal generating units 122-1 and 122-2 generates a control signal indicating a control output value MV (Manipulated Variable) based on the measurement value PV (Process Value) measured by each of the pressure gauges 121-1 and 121-2. This control signal is a signal for controlling the regulator valve 110. That is, the regulator valve 110 adjusts the aperture of its own valve using the control signal generated by each of the control signal generating units 122-1 and 122-2. Specifically, each of the control signal generating units 122-1 and 122-2 generates a control signal indicating an MV value for controlling the aperture of the regulator valve 110 so that the value of the PV measured by each of the pressure gauges 121-1 and 121-2 becomes a predetermined value. Note that only the control signal generating unit included in a control system may generate a control signal indicating the control output value MV based on the measurement value PV measured by the pressure gauge of its own system.

[0018] When its own system (its own system) is operating as a control system, each of the control signal generating units 122-1 and 122-2 outputs the control signal generated by itself to the switching unit 130. That is, when the system 120-1 is operating as a control system, the control signal generating unit 122-1 outputs the control signal generated by itself to the switching unit 130. Furthermore, when the system 120-2 is operating as a control system, the control signal generating unit 122-2 outputs the control signal generated by itself to the switching unit 130.

[0019] When the control signal generating units 122-1 and 122-2 are operating as standby systems, they each output the control signals output from the inter-system output units 123-2 and 123-1 of the other systems to the switching unit 130. That is, when the system 120-1 is operating as the standby system, the control signal generating unit 122-1 outputs the control signal output from the inter-system output unit 123-2 of the system 120-2 to the switching unit 130. When the system 120-2 is operating as the standby system, the control signal generating unit 122-2 outputs the control signal output from the inter-system output unit 123-1 of the system 120-1 to the switching unit 130. Each of the control signal generating units 122-1 and 122-2 recognizes whether the system it is operating as is currently the control system or the standby system based on a notification from the switching unit 130.

[0020] When each of the control signal generating units 122-1 and 122-2 switches its own system from a standby system to a control system, the control signal generating unit 122-1 and 122-2 generates a control signal based on a measurement value measured by the pressure gauge 121-1 and 121-2 of the own system, with the value of the control signal output to the switching unit 130 before the switching as an initial value, and outputs the generated control signal to the switching unit 130. In other words, when the system 120-1 is switched from the standby system to the control system, the control signal generating unit 122-1 generates a control signal based on a measurement value measured by the pressure gauge 121-1, with the value of the control signal output to the switching unit 130 before the switching as an initial value, and outputs the generated control signal to the switching unit 130. Furthermore, when the system 120-2 is switched from the standby system to the control system, the control signal generating unit 122-2 generates a control signal based on a measurement value measured by the pressure gauge 121-2, with the value of the control signal output to the switching unit 130 before the switching as an initial value, and outputs the generated control signal to the switching unit 130.

[0021] Each of the inter-system output units 123-1 and 123-2 outputs the control signal generated by the control signal generation units 122-1 and 122-2 to another system (a system other than the own system). Specifically, the inter-system output unit 123-1 outputs the control signal generated by the control signal generation unit 122-1 to the system 120-2. Furthermore, the inter-system output unit 123-2 outputs the control signal generated by the control signal generation unit 122-2 to the system 120-1. Note that only the inter-system output unit included in the system that is the control system may output the control signal generated by the control signal generation unit of its own system to the other system (standby system).

[0022] The fault detection units 125-1 and 125-2 detect the occurrence of a fault in the respective systems 120-1 and 120-2. The fault detection units 125-1 and 125-2 notify the switching unit 130 of the occurrence of the detected fault. Here, faults detected by the fault detection units 125-1 and 125-2 include, for example, a cutoff of the power supply to the systems 120-1 and 120-2, a stop of the output of signals from the pressure gauges 121-1 and 121-2, a value output from the pressure gauges 121-1 and 121-2 being outside a predetermined range, or a value of a signal generated by the control signal generation units 122-1 and 122-2 being outside a predetermined range. These faults can be determined to cause the systems 120-1 and 120-2 to malfunction, and are set arbitrarily in system design. Furthermore, the fault detection method is not particularly specified. For example, each of the failure detection units 125-1 and 125-2 may determine that a failure has occurred when the signal level of the output signal from each component exceeds a predetermined threshold or falls outside a predetermined range.

[0023] The switching unit 130 switches the system to be the control system based on notifications from the fault detection units 125-1 and 125-2. When switching the control system, the switching unit 130 notifies the control signal generation units 122-1 and 122-2 of the switching. The switching unit 130 outputs a control signal that controls the opening degree of the regulator valve 110, which is output from the system that is the control system, to the regulator valve 110. For example, if the current control system is system 120-1 and the standby system is system 120-2, the switching unit 130 outputs the control signal output from the control signal generation unit 122-1 of system 120-1 to the regulator valve 110. Thereafter, when the fault detection unit 125-1 notifies the switching unit 130 that a fault has been detected, the switching unit 130 switches the control signal to be output to the regulator valve 110 from the control signal output from the control signal generation unit 122-1 of system 120-1 to the control signal output from the control signal generation unit 122-2 of system 120-2. At this time, the switching unit 130 notifies the control signal generating unit 122-1 of the system 120-1 that the system has been switched from the control system to the standby system, and also notifies the control signal generating unit 122-2 of the system 120-2 that the system has been switched from the standby system to the control system.

[0024] The switching unit 130 may notify the systems 120-1 and 120-2 of whether they are the control system or the standby system continuously (for example, by using a level signal using a binary number where a value of "0" indicates that the system is the control system and a value of "1" indicates that the system is the standby system) or periodically (for example, by using a pulse signal) not only when switching between the control system and the standby system. If the switching unit 130 notifies the systems 120-1 and 120-2 only when switching between the control system and the standby system, each of the systems 120-1 and 120-2 may store a value indicating whether it is the control system or the standby system in a storage means such as a predetermined memory. Alternatively, the systems 120-1 and 120-2 may output a predetermined request signal to the switching unit 130, and the switching unit 130 may notify the systems 120-1 and 120-2 of whether they are the control system or the standby system in response to the request signal.

[0025] The following describes a control system switching method in the control system 100 shown in Fig. 2. Fig. 3 is a sequence diagram for explaining an example of a control system switching method in the control system 100 shown in Fig. 2. Take as an example a case where system 120-1 currently operates as a control system and system 120-2 operates as a standby system.

[0026] First, the inter-system output unit 123-1 outputs a control signal generated by the control signal generation unit 122-1 based on the measurement value measured by the pressure gauge 121-1 to the system 120-2 (step S1). Similarly, the inter-system output unit 123-2 outputs a control signal generated by the control signal generation unit 122-2 based on the measurement value measured by the pressure gauge 121-2 to the system 120-1 (step S2).

[0027] Currently, system 120-1 is the control system, so control signal generator 122-1 of system 120-1 outputs the generated control signal to switching unit 130 (step S3). On the other hand, system 120-2 is the standby system, so control signal generator 122-2 of system 120-2 outputs the control signal output from inter-system output unit 123-1 of system 120-1 to switching unit 130 (step S4).

[0028] Thereafter, when the fault detection unit 125-1 detects a fault in the system 120-1 (step S5), the fault detection unit 125-1 notifies the switching unit 130 of the detection of the fault (step S6). Then, the switching unit 130 switches the control system (step S7). Specifically, the switching unit 130 switches the system 120-1, which is currently operating as the control system, to the standby system, and switches the system 120-2, which is currently operating as the standby system, to the control system. The switching unit 130 also switches the control signal output to the regulator valve 110 from the control signal output from the control signal generation unit 122-1 of the system 120-1 to the control signal output from the control signal generation unit 122-2 of the system 120-2. The switching unit 130 notifies each of the systems 120-1 and 120-2 of the switch between the control system and the standby system (step S8). At this time, the switching unit 130 may notify each of the systems 120-1 and 120-2 only of the fact that the system has been switched between the control system and the standby system. Alternatively, the switching unit 130 may notify the system 120-1 of the fact that the system has been switched from the control system to the standby system, and may notify the system 120-2 of the fact that the system has been switched from the standby system to the control system.

[0029] Then, the control signal generating unit 122-2 of the system 120-2 recognizes that its own system 120-2 has been switched to the control system, and outputs the control signal generated by the control signal generating unit 122-2 to the switching unit 130 (step S9). At this time, the control signal generating unit 122-2 generates a control signal based on the measurement value measured by the pressure gauge 121-2, using the value of the control signal that was output to the switching unit 130 before the switching as the initial value, and outputs the generated control signal to the switching unit 130. Meanwhile, the control signal generating unit 122-1 of the system 120-1 recognizes that its own system 120-1 has been switched to the standby system, and outputs the control signal output from the inter-system output unit 123-2 of the system 120-2 to the switching unit 130 (step S10).

[0030] In this way, multiple systems are provided to control the regulator valves that regulate the pressure of the liquid flowing through the water treatment system. A control signal generated by the control system is output from that system and a standby system, and a switching unit outputs the control signal output from the system operating as the control system to the regulator valve. This redundant configuration allows PID (Proportional Integral Differential) control to continue even if a failure occurs in the operation of a control system, preventing the entire system from being shut down. Furthermore, by calculating the control signal output from the system switched from the standby system to the control system using the value output before the switch as the initial value, sudden changes in the control signal can be suppressed when switching control systems. In this way, this embodiment can reduce pressure fluctuations that occur when switching control systems with redundant configurations in a water treatment system. (Second embodiment)

[0031] Fig. 4 is a diagram showing an example of a specific configuration of a control system according to the second embodiment. As shown in Fig. 4, a control system 101 according to the second embodiment includes a regulator valve 110, systems 120-3 and 120-4, a switching unit 131, and an input unit 140. Note that Fig. 4 shows only the main components related to this embodiment among the components included in the control system 101. The regulator valve 110 is the same as that in the first embodiment.

[0032] The two systems 120-3 and 120-4 are systems that operate in mutually exclusive operating states: a control system that performs operation (control) and a standby system that stands by. When one of the systems 120-3 and 120-4 operates as a control system, the other operates as a standby system.

[0033] System 120-3 has a pressure gauge 121-1, a control signal generating unit 122-1, and an inter-system output unit 123-1. System 120-4 has a pressure gauge 121-2, a control signal generating unit 122-2, and an inter-system output unit 123-2. The pressure gauges 121-1 and 121-2, the control signal generating units 122-1 and 122-2, and the inter-system output units 123-1 and 123-2 are the same as those in the first embodiment.

[0034] The input unit 140 inputs information based on an external operation. The information input by the input unit 140 is information indicating which of the systems 120-3 and 120-4 is the control system or information indicating which is the standby system. Alternatively, the information input by the input unit 140 is information indicating switching of the control system. The input unit 140 may be any device that can input information based on an external operation. For example, the input unit 140 is a keyboard, a mouse, a touch panel, a switch, or the like.

[0035] The switching unit 131 switches the system to be the control system based on information input by the input unit 140. When the control system is switched, the switching unit 131 notifies the control signal generation units 122-1 and 122-2 of the switching. The switching unit 131 outputs a control signal that is output from the system that is the control system and that controls the aperture of the regulator valve 110 to the regulator valve 110. For example, if the current control system is system 120-3 and the standby system is system 120-4, the switching unit 131 outputs the control signal output from the control signal generation unit 122-1 of system 120-3 to the regulator valve 110. Thereafter, when information for switching the control system is input to the input unit 140, the switching unit 131 switches the control signal to be output to the regulator valve 110 from the control signal output from the control signal generation unit 122-1 of system 120-3 to the control signal output from the control signal generation unit 122-2 of system 120-4. At this time, the switching unit 131 notifies the control signal generating unit 122-1 of the system 120-3 that the system has been switched from the control system to the standby system, and also notifies the control signal generating unit 122-2 of the system 120-4 that the system has been switched from the standby system to the control system.

[0036] The switching unit 131 may notify the systems 120-3 and 120-4 continuously (for example, using a level signal) or periodically (for example, using a pulse signal) whether each of the systems 120-3 and 120-4 is the control system or the standby system, not only when switching between the control system and the standby system. If the switching unit 131 notifies the systems 120-3 and 120-4 only when switching between the control system and the standby system, a numerical value indicating whether each of the systems 120-3 and 120-4 is the control system or the standby system may be stored in a storage unit such as a predetermined register in each of the systems 120-3 and 120-4. Alternatively, a predetermined request signal may be output from the systems 120-3 and 120-4 to the switching unit 131, and the switching unit 131 may notify each of the systems 120-3 and 120-4 whether each of the systems is the control system or the standby system in response to the request signal.

[0037] The following describes a control system switching method in the control system 101 shown in Fig. 4. Fig. 5 is a sequence diagram for explaining an example of a control system switching method in the control system 101 shown in Fig. 4. Take as an example a case where system 120-3 currently operates as the control system and system 120-4 operates as the standby system.

[0038] First, the inter-system output unit 123-1 outputs a control signal generated by the control signal generation unit 122-1 based on the measurement value measured by the pressure gauge 121-1 to the system 120-4 (step S21). Similarly, the inter-system output unit 123-2 outputs a control signal generated by the control signal generation unit 122-2 based on the measurement value measured by the pressure gauge 121-2 to the system 120-3 (step S22).

[0039] Currently, system 120-3 is the control system, so control signal generator 122-1 of system 120-3 outputs the generated control signal to switching unit 131 (step S23). On the other hand, system 120-4 is the standby system, so control signal generator 122-2 of system 120-4 outputs the control signal output from inter-system output unit 123-1 of system 120-3 to switching unit 131 (step S24).

[0040] Thereafter, when the input unit 140 receives an external operation for switching the control system (step S25), the input unit 140 outputs the information input based on the received operation to the switching unit 131 (step S26). Then, the switching unit 131 switches the control system (step S27). Specifically, the switching unit 131 switches the system 120-3, which is currently operating as the control system, to the standby system, and switches the system 120-4, which is currently operating as the standby system, to the control system. Furthermore, the switching unit 131 switches the control signal output to the regulator valve 110 from the control signal output from the control signal generating unit 122-1 of the system 120-3 to the control signal output from the control signal generating unit 122-2 of the system 120-4. The switching unit 131 notifies each of the systems 120-3 and 120-4 of the switching between the control system and the standby system (step S28). At this time, the switching unit 131 may notify each of the systems 120-3 and 120-4 only of the fact that the control system and the standby system have been switched over. Alternatively, the switching unit 131 may notify the system 120-3 of the fact that the control system has been switched over to the standby system, and may notify the system 120-4 of the fact that the standby system has been switched over to the control system.

[0041] Then, the control signal generating unit 122-2 of the system 120-4 recognizes that its own system 120-4 has been switched to the control system, and outputs the control signal generated by the control signal generating unit 122-2 to the switching unit 131 (step S29). At this time, the control signal generating unit 122-2 generates a control signal based on the measurement value measured by the pressure gauge 121-2, using the value of the control signal that was output to the switching unit 131 before the switching as the initial value, and outputs the generated control signal to the switching unit 131. Meanwhile, the control signal generating unit 122-1 of the system 120-3 recognizes that its own system 120-3 has been switched to the standby system, and outputs the control signal output from the inter-system output unit 123-2 of the system 120-4 to the switching unit 131 (step S30).

[0042] In this way, multiple systems are provided to control the control valves that regulate the pressure of the liquid flowing through the water treatment system. A control signal generated by the control system is output from that system and a standby system, and a control signal output from the system operating as the control system is output to the control valve by a switching unit. This redundant configuration allows PID control to continue, preventing the entire system from being shut down, even if it becomes necessary to stop the operation of the currently operating system for maintenance or other reasons. Furthermore, by calculating the control signal output from the system switched from the standby system to the control system using the value output before the switch as the initial value, sudden changes in the control signal can be suppressed when switching control systems. In this way, this embodiment can reduce pressure fluctuations that occur when switching control systems with redundant configurations in a water treatment system. (Third embodiment)

[0043] Fig. 6 is a diagram showing an example of a specific configuration of a control system according to the second embodiment. As shown in Fig. 6, a control system 102 according to the second embodiment includes a regulator valve 110, systems 120-1 and 120-2, a switching unit 130, and a delay unit 150. Note that Fig. 6 shows only the main components related to this embodiment among the components included in the control system 102. The regulator valve 110, systems 120-1 and 120-2, and switching unit 130 are the same as those in the first embodiment.

[0044] The delay unit 150 delays the timing at which one system receives a control signal output from the inter-system output unit of the other system. Specifically, the delay unit 150 delays the control signal output from the inter-system output unit 123-1 of system 120-1 by a predetermined time and outputs it to the control signal generation unit 122-2 of system 120-2. The delay unit 150 also delays the control signal output from the inter-system output unit 123-2 of system 120-2 by a predetermined time and outputs it to the control signal generation unit 122-1 of system 120-1. The length of this delay time is not particularly specified. Furthermore, a general delay element may be used as the means for delaying the time, and is not particularly specified.

[0045] In this manner, multiple systems are provided to control the regulator valves that regulate the pressure of the liquid flowing through the water treatment system. A control signal generated by the control system is output from that system and a standby system, and the control signal output from the system operating as the control system is output to the regulator valve by the switching unit. This redundant configuration allows PID control to continue even if a failure occurs in the operation of a control system, preventing the entire system from being halted. Furthermore, by calculating the control signal output from the system switched from the standby system to the control system using the value output before the switch as the initial value, sudden changes in the control signal can be suppressed when switching the control system. Furthermore, the control signal output from one system to the other system is delayed. This allows the timing of the control signal switch to be later than the timing of the control system switch by the switching unit 130. In this manner, this embodiment reduces pressure fluctuations that occur when switching control systems with redundant configurations in a water treatment system.

[0046] 1 , the present invention can also be applied to a configuration in which, for example, pump 300 pumps liquid from water tank 200 and supplies it to control system 100, and the liquid controlled by control system 100 is supplied to point of use 400. In this case, the liquid controlled by control system 100 is returned to water tank 200. Furthermore, in the above-described configuration, an example of control based on pressure has been described, but control based on flow rate, water level, or temperature (water temperature) may also be used. Furthermore, the present invention can also be applied to a system that adjusts control devices other than control valves (for example, inverters, etc.).

[0047] Although the above description has been given by allocating each function (process) to each component, this allocation is not limited to the above. Furthermore, the configuration of the components is also not limited to the above-described embodiments, which are merely examples. Furthermore, each embodiment may be combined. [Explanation of symbols]

[0048] 100~102 Control System 110 Control valve 120-1 to 120-4 series 121-1, 121-2 Pressure gauge 122-1, 122-2 Control signal generation unit 123-1, 123-2 Intersystem output section 125-1, 125-2 Fault detection unit 130,131 Switching section 140 Input section 150 Delay section 200 aquariums 300 pump 400 Use Points

Claims

1. a regulator valve for regulating the pressure of a liquid flowing through a flow path of the water treatment system; Two systems, either a control system or a standby system, which operate mutually exclusively; a switching unit that outputs a control signal that controls the opening degree of the regulator valve, the control signal being output from the control system, to the regulator valve; Each of the two systems is a pressure gauge located upstream of the regulating valve for measuring the water pressure of the liquid flowing through the flow path; When the system is the control system, a control signal generating unit generates the control signal based on a measurement value measured by the pressure gauge included in the system and outputs the generated control signal to the switching unit; an inter-system output unit that outputs the control signal generated by the control signal generation unit of the control system to the control signal generation unit of the standby system; a delay unit that delays the timing at which the control signal output from the inter-system output unit included in one of the control systems is received by the control signal generation unit included in the standby system, When the system is the standby system, the control signal generating unit outputs the control signal output from the inter-system output unit of the system that is the control system to the switching unit, and when the system is switched from the standby system to the control system, the control signal generating unit generates the control signal based on the measurement value measured by the pressure gauge of the system, using the value of the control signal output before the switching as an initial value, and outputs the generated control signal to the switching unit.

2. 2. The control system of claim 1, the system has a failure detection unit that detects the occurrence of a failure in the system and notifies the switching unit of the detected failure; The switching unit switches the system to be the control system based on a notification from the failure detection unit, and notifies the control signal generation unit of the switching.

3. 3. The control system according to claim 1 or 2, an input unit for inputting information based on an external operation; The switching unit switches the system to be the control system based on the information input by the input unit, and notifies the control signal generating unit of the switching.

4. A control system switching method for a water treatment system having two systems, one of a control system and a standby system, which operate exclusively with respect to each other, comprising: a process in which a pressure gauge provided in each of the two systems measures the water pressure of the liquid upstream of a control valve that adjusts the pressure of the liquid flowing through a flow path of the water treatment system; A process in which the control system generates a control signal for controlling the opening degree of the regulator valve based on the measured value; a process in which the control system outputs the generated control signal to the standby system; a process in which the control system outputs the generated control signal to the regulator valve; a process of delaying the timing at which the standby system receives the control signal output from the control system; A control system switching method for a water treatment system, in which, when the standby system is switched to the control system, the value of the control signal output from the control system before the switching is set as an initial value, the control signal is generated based on the measurement value measured by the pressure gauge of the control system, and the generated control signal is output to the adjustment valve.

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