Pump control device and pump control method

Abstract

To provide a pump control method which can easily prevent a water hammer.SOLUTION: Installation heights of all pipes 101 connected to a discharge port side of a pump P are stored. Open / closed states of valves 102 provided in all pipes 101 are acquired. A head pressure of one, having the highest installation height, of the pipes 101 in which the valve 102 provided therein is in the open state is calculated. When a water pressure detected around the discharge port of the pump P is equivalent to the calculated head pressure, the pump P can be activated.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pump control device and a pump control method for controlling the startup of a pump.

Background Art

[0002] For example, when a pump is started in a state where water has leaked from the system of a power plant, the water is rapidly pressurized and the pressure rises, causing water hammer and water surge, which may lead to pipe detachment and equipment damage. To solve such problems, a method has been known in which an operator gradually opens the outlet valve when starting the pump to prevent rapid pressure rise.

[0003] Also, a water hammer prevention device is known that can prevent the occurrence of water hammer over a long period with a simple mechanism (see, for example, Patent Document 1). This device has a primary water passage penetrating through a case, a piston slidably installed in the case, and a spring member that biases the piston in one direction of the sliding direction. When the piston slides in the other direction by the water pressure of the water flowing through the primary water passage, a secondary water passage into which the water flowing through the primary water passage can flow is formed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, power plants are equipped with numerous pumps, pipes, waterways, and outlet valves. Therefore, gradually opening all outlet valves when starting up a pump requires considerable effort and time. Moreover, for equipment that is started frequently, operators must handle this each time, which requires a great deal of effort and time. Furthermore, the device described in Patent Document 1 requires the installation of the device in all pipes and waterways, necessitating large-scale equipment modifications that incur significant costs and time.

[0006] Therefore, the present invention aims to provide a pump control device and a pump control method that can easily prevent water hammer. [Means for solving the problem]

[0007] To solve the above problems, the invention of claim 1 is: Power plant The system includes: a system information storage means for storing the installation height of all piping connected to the discharge port side of the pump; and a control means for acquiring the open / closed state of valves installed in all the piping, calculating the hydrostatic pressure of the piping with the highest installation height among the piping with open valves, and enabling the pump to start when the water pressure detected around the discharge port of the pump is equal to the hydrostatic pressure. The control means enables the pump to be started if the water pressure detected around the discharge port of the pump is not equal to the hydrostatic pressure, and when the pump is started, it fully closes the valve in the open state and then gradually opens it. This is a pump control device characterized by the following features.

[0009] Claim 2 The invention is Power plant The system stores the installation height of all piping connected to the pump's discharge port, obtains the open / closed state of the valves installed in all of the piping, calculates the hydrostatic pressure of the piping with the highest installation height among the piping with open valves, and enables the pump to start if the water pressure detected around the pump's discharge port is equal to the hydrostatic pressure. death , If the water pressure detected around the discharge port of the pump is not equal to the hydrostatic pressure, the pump is made activatable, and when the pump is activated, the valve that is in the open state is fully closed and then gradually opened. This is a pump control method characterized by the following features. [Effects of the Invention]

[0011] Claim 1 and Claim 2According to the invention described above, if the calculated hydrostatic pressure at the highest point in the piping connected to the pump with an open valve is equal to the water pressure detected around the pump's discharge port, it is determined that all the piping through which water is supplied is filled with water, and the pump can be started. In other words, if all the piping is filled with water, water hammer does not occur, and the pump can be started. If all the piping is not filled with water, the pump cannot be started, and water hammer can be prevented.

[0012] In this way, water hammer can be prevented before the pump is started, reducing the need for operator intervention and control. Furthermore, since it only requires calculating the water head pressure at the highest point of the piping and detecting and measuring the water pressure around the pump's discharge port, water hammer can be easily prevented even with many pipes and valves installed, and it can be easily applied to existing equipment.

[0013] Claim 1 and claims 2 According to the invention described above, if the calculated water head pressure and the detected water pressure are not equal, that is, if it is determined that not all pipes through which water is supplied are filled with water, the pump becomes operational, and when it is started, the valve is gradually opened. Therefore, even if the pipes are not filled with water, a rapid increase in pressure and filling is prevented, and water hammer can be prevented.

[0014] Moreover, claims 1 and Claims According to the invention described in 2, since the valve is opened gradually automatically, it is possible to reduce the need for operator intervention and operation, and it is also possible to respond quickly even when many pipes and valves are installed. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing the configuration of a pump control device according to an embodiment of the present invention. [Figure 2]It is a schematic configuration block diagram showing the pump control device of FIG. 1. [Figure 3] It is a flowchart showing the control operation of the pump control device of FIG. 1.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, this invention will be described based on the illustrated embodiments.

[0017] FIG. 1 is a schematic configuration diagram showing the arrangement state of the pump control device 1 according to an embodiment of this invention. This pump control device 1 is a device that controls the startup of the pump P, etc. In this embodiment, the case of controlling the pump P in a power plant will be described, but it is of course applicable to the pump P in other facilities and buildings. Further, the case of sending water by the pump P will be described, but it may be a liquid other than water.

[0018] Here, a large number of pumps P are arranged in the power plant, and one or a plurality of pipes 101 are connected to the discharge port side of each pump P, and a valve 102 is arranged in each pipe 101. When the pump P starts up, the water in the tank 103 is sucked up and sent to each pipe 101, and is supplied through the valve 102 in the open state.

[0019] Also, the valve 102 can be remotely controlled to open and close, for example, it is composed of a solenoid valve, and as will be described later, it can be opened and closed according to a slow opening signal from the pump control device 1, etc. Further, the opening and closing state of the valve 102 can be acquired and monitored from the valve control unit 5 of the pump control device 1 described later. In addition, when all the opening and closing of the valve 102 are controlled by the pump control device 1, it is possible for the pump control device 1 to recognize without acquiring the opening and closing state from the valve 102.

[0020] A pump control device 1 is arranged for a water supply system of such a pump P. In this embodiment, a case where one pump control device 1 is arranged for a water supply system of one pump P will be described. However, one pump control device 1 may be arranged for a water supply system of a plurality of pumps P, and a plurality of pumps P and the like may be controlled by one pump control device 1.

[0021] Also, a pressure gauge 2 is arranged around the discharge port of the pump P to detect and measure the water pressure around the discharge port of the pump P (the head pressure actually applied to the pump P). If this pressure gauge 2 is arranged in an existing water supply system, it may be used. If it is not arranged, it is arranged together with the pump control device 1.

[0022] The pump control device 1 is communicably connected to the pressure gauge 2, the pump P, and each valve 102. As shown in FIG. 2, it mainly includes a system information storage unit (system information storage means) 3, a start control unit (control means) 4, a valve control unit (control means) 5, and a central processing unit (control means) 6 for controlling these.

[0023] The system information storage unit 3 is a memory storage device that stores system information including the installation height of all pipes 101 connected to each pump P. That is, for each pump P, identification information of all pipes 101 connected to it, the installation height (the highest height filled with water) of each pipe 101 from the discharge port of the pump P, identification information of the valve 102 arranged in each pipe 101, etc. are stored as system information.

[0024] The start control unit 4 is a control circuit / interface for controlling the start of the pump P, and transmits a start signal to the pump P as will be described later in response to a control command from the central processing unit 6.

[0025] The valve control unit 5 is a control circuit / interface for acquiring the opening / closing state of each valve 102 and controlling the opening / closing of each valve 102, and transmits a slow opening signal or the like to each valve 102 as will be described later in response to a control command from the central processing unit 6.

[0026] The central processing unit 6 is a central control unit that determines whether or not the area to which water is sent and flows (water-filled area) when the pump P is started is filled with water, and sends control commands to the start control unit 4 and the valve control unit 5. In other words, if the water-filled area is filled with water, starting the pump P will not cause water hammer, so it permits the pump P to start (it starts as is). On the other hand, if the water-filled area is not filled with water and the pump P is started, water hammer will occur, so it interlocks the start of the pump P (prevents it from starting), or it gradually opens the valve 102 when the pump P is started.

[0027] Specifically, as shown in Figure 3, first, the open / closed state of the valves 102 installed in all the pipes 101 connected to the discharge port side of the pump P is obtained (step S1). Next, the hydrostatic pressure of the pipe 101 with the highest installation height within the water-filled range is calculated (step S2). That is, among the pipes 101 with valves 102 in the open state, the height of the pipe 101 with the highest installation height is searched and obtained from the system information of the system information storage unit 3, and the hydrostatic pressure (water pressure that should be applied around the discharge port of the pump P) based on that highest height is calculated. Specifically, the weight / load that should be applied around the discharge port of the pump P, which is calculated based on the specific gravity of water, the highest height, the area of ​​the pipes 101, etc., is calculated by dividing it by the area around the discharge port of the pump P.

[0028] Meanwhile, the water pressure around the discharge port of pump P, detected and measured by pressure gauge 2, is obtained (step S3). Next, it is determined whether the calculated value of the water pressure calculated in step S2 and the measured value of the water pressure obtained in step S3 are equivalent (step S4). Here, equivalent means that the difference between the calculated value and the measured value is within a predetermined range, and it is considered that the water-filling range is filled with water. For example, if the difference between the calculated value and the measured value is within the error range of the calculation or measurement, or if the calculated value is higher than the measured value, it is determined that they are equivalent.

[0029] Furthermore, if the pressure from the previous pump startup remains in piping 101 (because valve 102 in the system is closed and no water has drained from piping 101, leaving it pressurized), the pressure inside the piping (discharge pressure of pump P) may exceed the calculated value. Therefore, the measured value may also be equal to or greater than the calculated value.

[0030] Then, if the calculated value and the measured value are the same (if the answer is "Y" in step S4), the pump P is made activatable (activation permitted) (step S5). In other words, the pump P is made activatable unconditionally without interlocking or locking its operation, or an activation signal is sent to the pump P to activate it.

[0031] On the other hand, if the calculated value and the measured value are not equivalent (if the result is "N" in step S4), the startup of pump P is restricted (step S6). Here, the restriction includes the following control actions: Firstly, a message is displayed and notified, for example, on a terminal at the power plant's monitoring center or on the operator's terminal, that there is a risk of water hammer occurring. Secondly, an interlock is placed on the startup of pump P to prevent it from starting. Thirdly, while enabling the startup of pump P, the valve 102, which is open when pump P is started, is fully closed and then gradually opened (a fully closed signal is sent to valve 102, followed by a slowly opening signal). Furthermore, which of these restrictions and actions are performed may be fixedly selected and set in advance for each pump P, or they may be selectable and changed at any time for any pump P.

[0032] Thus, if the calculated hydrostatic pressure around the discharge port of pump P is not the same as the hydrostatic pressure around the discharge port of pump P that is actually measured, it is assumed that the water-filling range is not filled with water and there is a risk of water hammer occurring, in which case an interlock or similar measure is applied to the start of pump P.

[0033] Such control can be performed at any time, but for example, when a request to start pump P is received (when the pump P start button is turned on), the above control may be performed on the target pump P. That is, if the calculated hydrostatic head pressure is the same as the actual hydrostatic head pressure, pump P is started as is; if they are not the same, pump P is not started, or if pump P is started, valve 102 is gradually opened at the same time to prevent water hammer from occurring.

[0034] Furthermore, the above-described control may be performed periodically. That is, for all pumps P, it is periodically determined whether the calculated value and the measured value of the hydrostatic pressure are equivalent, and if they are not equivalent, an interlock is applied or the fact that they are not equivalent is recorded, and this process is repeated. Then, when a request to start a specific pump P is input, based on the previous determination result for that pump P, the pump P is started as is, the start of the pump P is locked, or the valve 102 is gradually opened at the same time as the pump P is started.

[0035] Next, a pump control method according to an embodiment of this invention will be described, which is basically the same control method as the control operation of the pump control device 1 shown in Figure 3 above.

[0036] Specifically, first, the installation height of all piping 101 connected to the discharge port side of each pump P is stored. Next, the open / closed state of the valves 102 of all piping 101 connected to the pump P to be controlled is obtained, and the hydrostatic head pressure of the pipe 101 with the highest installation height among the piping 101 where the valve 102 is in an open state is calculated. In addition, the hydrostatic head pressure around the discharge port of the pump P is measured and it is determined whether the calculated value and the measured value of the hydrostatic head pressure are equivalent. As a result, if they are equivalent, the pump P is made activatable; otherwise, the pump P is either not activated, or the valve 102 is gradually opened at the same time as the pump P is activated.

[0037] As described above, with the pump control device 1 and pump control method configured in this way, if the calculated hydrostatic pressure at the highest point of the piping 101 connected to the pump P and with the valve 102 open is equal to the actual hydrostatic pressure around the discharge port of the pump P, it is determined that all the piping 101 (water-filled range) through which water is supplied is filled with water, and the pump P can be started. In other words, if all the piping 101 is filled with water, water hammer will not occur, and the pump P can be started. If all the piping 101 is not filled with water, the pump P cannot be started, thus preventing water hammer.

[0038] In this way, water hammer can be prevented before starting pump P, thus reducing the need for operator intervention and operation. Furthermore, since it is only necessary to calculate the water head pressure at the highest point of piping 101 and detect and measure the water pressure around the discharge port of pump P, water hammer can be easily prevented even if many pipes 101 and valves 102 are installed, and it can also be easily applied to existing equipment.

[0039] Furthermore, if the calculated hydrostatic head pressure and the detected actual hydrostatic head pressure are not equal, that is, if it is determined that not all of the pipes 101 through which water is supplied are filled with water, the pump P will be made operational, and when it is started, the valve 102 may be gradually opened. In this case, even if the pipes 101 are not filled with water, a rapid increase in pressure and filling will be prevented, thus preventing water hammer.

[0040] Furthermore, since the valve 102 is opened gradually automatically by the pump control device 1, it is possible to reduce the need for operator intervention and operation, and it is also possible to respond quickly even if many pipes 101 and valves 102 are installed.

[0041] Although embodiments of this invention have been described in detail above, the specific configuration is not limited to these embodiments, and any design changes, etc., that do not depart from the gist of this invention are also included. For example, in the above embodiment, one of the restrictions on starting the pump P was described as notifying a predetermined terminal, but an alarm lamp could be provided around the pump P's start button and made to light up or flash. [Explanation of symbols]

[0042] 1. Pump control device 2. Pressure gauge 3 System information storage unit (system information storage means) 4. Startup control unit (control means) 5. Valve control unit (control means) 6. Central Processing Unit (Control Means) P Pump 101 Piping 102 valves

Claims

1. A system information storage means for storing the installation height of all piping connected to the discharge port side of a pump at a power plant, A control means that acquires the open / closed state of valves installed in all of the aforementioned pipes, calculates the hydrostatic head pressure of the pipe with the highest installation height among the pipes where the valves are in the open state, and enables the pump to start when the water pressure detected around the discharge port of the pump is equal to the hydrostatic head pressure, Equipped with, The control means enables the pump to be started if the water pressure detected around the discharge port of the pump is not equal to the hydrostatic pressure, and when the pump is started, it fully closes the valve that is in the open state and then gradually opens it. A pump control device characterized by the following features.

2. Store the installation height of all piping connected to the discharge port side of the pump of the power plant, The open / closed state of the valves installed in all of the aforementioned pipes is obtained, the hydrostatic head pressure of the pipe with the highest installation height among the pipes with open valves is calculated, and the pump is made operational when the water pressure detected around the discharge port of the pump is equal to the hydrostatic head pressure. If the water pressure detected around the discharge port of the pump is not equal to the hydrostatic pressure, the pump is made activatable, and when the pump is activated, the valve that is in the open state is fully closed and then gradually opened. A pump control method characterized by the following:

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