Opening degree calculation system, opening degree calculation method, and program

Abstract

The objective is to provide a valve opening degree calculation system, a valve opening degree calculation method, and a program that can calculate the valve opening degree using the flow rate downstream of a reference point. [Solution] The system is characterized by comprising: an upstream pressure acquisition means 151 that acquires the pressure on the upstream side with respect to the control valve; a downstream pressure acquisition means 152 that acquires the target pressure on the downstream side with respect to the control valve; a flow rate measuring means 153 that measures the flow rate on the downstream side; and an opening degree calculation means 157 that calculates the opening degree of the control valve based on the upstream pressure acquired by the upstream pressure acquisition means 151, the downstream target pressure acquired by the downstream pressure acquisition means 152, and the flow rate measured by the flow rate measuring means 153.

Description

Technical Field

[0001] The present disclosure relates to an opening degree calculation system, an opening degree calculation method, and a program.

Background Art

[0002] Conventionally, in order to maintain the pressure at a target set value, the opening degree of an operation valve has been opened and closed. Patent Document 1 discloses deriving the flow coefficient of each operation valve in a steady state capable of realizing a target set value of flow rate, a target set value of pressure, and a target set value of pressure different from the said pressure, and obtaining the operation amount of each operation valve.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, it was not assumed to obtain the operation amount (opening degree) of the operation valve using the flow rate on the downstream side based on the operation valve.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide an opening degree calculation system, an opening degree calculation method, and a program capable of calculating the opening degree of a valve using the flow rate on the downstream side from a reference.

Means for Solving the Problems

[0006] An opening degree calculation system according to one aspect of the present disclosure is characterized by comprising: an upstream acquisition means for acquiring the pressure on the upstream side with respect to the control valve; a downstream acquisition means for acquiring a target pressure on the downstream side with respect to the control valve; a flow rate measuring means for measuring the flow rate on the downstream side; and an opening degree calculation means for calculating the opening degree of the control valve based on the upstream pressure acquired by the upstream acquisition means, the target pressure on the downstream side acquired by the downstream acquisition means, and the flow rate measured by the flow rate measuring means. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a valve opening degree calculation system, a valve opening degree calculation method, and a program that can calculate the valve opening degree using the flow rate downstream of a reference. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a boiler system according to an embodiment. [Figure 2] This is a loop diagram showing the control loop of a boiler system according to an embodiment. [Figure 3] This is a schematic block diagram showing the system configuration of the opening degree calculation system according to the embodiment. [Figure 4] This graph shows the relationship between the CV value and the opening degree of the control valve. [Figure 5] This graph shows the relationship between the opening degree of the control valve and the CV value. [Figure 6] This figure shows a control block for an opening degree calculation system according to an embodiment. [Figure 7] Figure 1 shows the results of the control adjustment of the feedback control of the opening degree of the control valve. [Figure 8] Figure 2 shows the results of the control adjustment of the feedback control of the opening degree of the control valve. [Figure 9] Figure 3 shows the results of the control adjustment of the feedback control of the opening degree of the control valve. [Figure 10] This is an example of a control screen for adjusting the opening of a control valve. [Figure 11]This is an example of the detailed settings screen for the opening degree of a control valve. [Figure 12] This graph displays theoretical and actual flow rates for comparison. [Figure 13] This is a flowchart of the method for calculating the opening degree according to the embodiment. [Figure 14] This figure shows a schematic example of the hardware configuration of the information processing device applied to this embodiment. [Modes for carrying out the invention]

[0009] The following describes, with reference to the drawings, an opening degree calculation system and an opening degree calculation method according to one embodiment of this disclosure. The opening degree calculation system according to this embodiment is used to calculate the opening degree of a control valve in a boiler system. First, the boiler system according to this embodiment will be described. The boiler equipment of this embodiment is used, for example, in a food processing plant. The performance standards required for boiler equipment in a food processing plant are stringent, and specifically, for example, it is required that the temperature of the supplied steam does not change. Temperature changes in the supplied steam occur, for example, due to changes in the pressure or flow rate of the supplied steam. The opening degree calculation system according to this embodiment contributes to maintaining a constant temperature of supplied steam by appropriately adjusting the opening degree of the control valve in the boiler equipment to maintain the pressure and flow rate of supplied steam at target values.

[0010] Figure 1 is a schematic diagram of boiler equipment B according to an embodiment. As shown in Figure 1, boiler equipment B comprises a steam drum BD, piping P, and a control valve V. In boiler equipment B shown in Figure 1, steam stored in steam drum BD moves through piping P. At this time, the pressure and flow rate of the steam moving inside piping P are adjusted by appropriately adjusting the opening of the control valve V installed in piping P. Furthermore, it is preferable to appropriately select the type and diameter of the control valve V in accordance with the flow rate and other conditions required in the boiler equipment B.

[0011] FIG. 2 is a loop diagram showing a control loop of the boiler facility B according to the embodiment. In the loop diagram shown in FIG. 2, each of the above-described components included in the boiler facility B and various sensors provided in the boiler facility B are schematically shown. Further, in the loop diagram shown in FIG. 2, communication paths between each component and various sensors of the boiler facility B and the control logic CL are schematically shown.

[0012] Note that the loop diagram shown in FIG. 2 may be visually displayed on the display unit 13, which will be described later, as a user interface showing the states of each component and various sensors of the boiler facility B. As information indicating the state of the boiler facility B, in the example shown in FIG. 2, the measured value of the flow rate in the control valve V to be described later is shown as 20.85 t / h (ton / hour), and the theoretical value is shown as 19.00 t / h. Not limited to this, various information regarding the states of each component and various sensors of the boiler facility B may be appropriately displayed in the loop diagram shown in FIG. 2.

[0013] Hereinafter, as shown in FIGS. 1 and 2, in the boiler facility B, the side of the pipe P closer to the steam drum BD than the control valve V is referred to as the upstream side, and the side farther from the steam drum BD than the control valve V is referred to as the downstream side. In the boiler facility B having the above-described configuration, by appropriately adjusting the opening degree of the control valve V by each of the components to be described later, it follows the predetermined pressure and flow rate required on the downstream side.

[0014] As shown in FIG. 2, the boiler facility B of the present embodiment is provided with an upstream pressure sensor US1, an upstream temperature sensor US2, an upstream flow rate sensor US3, a downstream pressure sensor DS1, a downstream temperature sensor DS2, and a downstream flow rate sensor DS3.

[0015] The upstream pressure sensor US1 is a pressure sensor provided on the upstream side with reference to the control valve V. The upstream pressure sensor US1 may be provided, for example, in the steam drum BD. The upstream pressure sensor US1 may measure, for example, the pressure inside the steam drum BD. The upstream temperature sensor US2 is a temperature sensor installed upstream of the control valve V. The upstream temperature sensor US2 may be installed, for example, in the piping P. The upstream temperature sensor US2 may measure, for example, the temperature inside the upstream piping P. The upstream flow sensor US3 is a flow sensor installed upstream of the control valve V. The upstream flow sensor US3 may be installed, for example, in the piping P. The upstream flow sensor US3 may measure, for example, the flow rate of steam inside the upstream piping P.

[0016] The downstream pressure sensor DS1 is a pressure sensor located downstream of the control valve V. The downstream pressure sensor DS1 may be installed, for example, in the piping P. The downstream pressure sensor DS1 may measure, for example, the pressure inside the downstream piping P. The downstream temperature sensor DS2 is a temperature sensor located downstream of the control valve V. The downstream temperature sensor DS2 may be installed, for example, in the piping P. The downstream temperature sensor DS2 may measure, for example, the temperature inside the downstream piping P.

[0017] The downstream flow sensor DS3 is a flow sensor installed downstream of the control valve V. The downstream flow sensor DS3 may be installed, for example, in the piping P. The downstream flow sensor DS3 may measure, for example, the flow rate of steam inside the downstream piping P. In this embodiment, the downstream flow sensor DS3 may output the measured flow rate as a current value of 4-20mA. The output current value may be transmitted via a network N to the flow rate measuring means 153, which will be described later, by a transmitter (not shown). Furthermore, the downstream flow sensor DS3 may output an abnormal signal indicating that the flow rate value is abnormal if the measured flow rate value is abnormal, that is, if the current value related to the measured value is outside the range of 4-20mA (for example, if it is 3.84mA or less or 20.16mA or more).

[0018] As shown in Figure 2, each of the sensors described above is connected to the control logic CL via the network N. Each sensor may transmit the measured values ​​of pressure, temperature, and flow rate it detects to the control logic CL via the network N. In this embodiment, it is preferable that the sensors described above enable monitoring of at least the pressure on the upstream and downstream sides, and the required flow rate on the downstream side (secondary side). Since the correction of pressure loss by the flow rate sensor can be avoided by controlling the control valve V, it is preferable that the required flow rate on the downstream side (secondary side) is determined based on the measured value of the downstream flow rate sensor DS3.

[0019] Figure 3 is a schematic block diagram showing the system configuration of the opening degree calculation system 1 according to the embodiment. As shown in Figure 3, the opening degree calculation system 1 includes a terminal device 10. The terminal device 10 and each of the sensors described above are connected to each other via a network N. In other words, the control logic CL shown in Figure 2 may be included in the terminal device 10. In other words, the control logic CL shown in Figure 2 may be stored in the storage unit 14 of the terminal device 10, which will be described later. Network N may be a network using wireless communication or a network using wired communication. Network N may be configured using, for example, the Internet or a local area network (LAN). Network N may be configured by combining multiple networks.

[0020] Figure 3 is a schematic block diagram showing a specific example of the functional configuration of the terminal device 10. The terminal device 10 is configured using information devices such as a smartphone, tablet, personal computer, or dedicated device. The terminal device 10 includes a communication unit 11, an input unit 12, a display unit 13, a storage unit 14, and a control unit 15.

[0021] The communication unit 11 is a communication device. The communication unit 11 may be configured, for example, as a network interface. The communication unit 11 communicates data with other devices via the network N in accordance with the control of the control unit 15. The communication unit 11 may be a device that performs wireless communication or a device that performs wired communication.

[0022] The input unit 12 is configured using existing input devices such as a keyboard, pointing device (mouse, tablet, etc.), buttons, or touch panel. The input unit 12 is operated by the user when inputting user instructions to the terminal device 10. The input unit 12 may also be an interface for connecting the input device to the terminal device 10. In this case, the input unit 12 inputs the input signal generated in the input device in response to the user's input to the terminal device 10. The input unit 12 may also be configured using a microphone and a speech recognition device. In this case, the input unit 12 acquires the acoustic signal generated by the user's speech, performs speech recognition on the words spoken by the user, and inputs the recognized string information to the terminal device 10. The speech recognition process may be performed by the control unit 15. The input unit 12 may be configured in any way that allows user instructions to be input to the terminal device 10.

[0023] The display unit 13 outputs information in a format that the user can recognize. The display unit 13 may be an image display device such as a liquid crystal display or an organic EL (Electro-Luminescence) display. The display unit 13 may also be an interface for connecting the image display device to the terminal device 10. In this case, the display unit 13 generates a video signal for displaying image data and outputs the video signal to the image display device connected to it. The display unit 13 may also be configured as a touch panel integrated with the input unit 12.

[0024] The storage unit 14 is configured using a storage device such as a magnetic hard disk drive or a semiconductor storage device. The storage unit 14 stores data used by the control unit 15. The storage unit 14 stores data necessary when the control unit 15 performs processing.

[0025] The control unit 15 is configured using a processor such as a CPU (Central Processing Unit) and memory (main memory). The control unit 15 functions as an upstream acquisition means 151, a downstream acquisition means 152, a flow rate measurement means 153, an abnormality determination means 154, a flow rate determination means 155, a CV value acquisition means 156, an opening degree calculation means 157, a flow rate calculation means 158, a normal determination means 159, a first control means 15A, a second control means 15B, a display control means 15C, and an alarm means 15D, as the processor executes a program. Note that all or part of each function of the control unit 15 may be implemented using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The above program may be recorded on a computer-readable recording medium. Computer-readable recording media include, for example, portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and semiconductor storage devices (e.g., SSDs: Solid State Drives), as well as storage devices such as hard disks and semiconductor storage devices built into computer systems. The above program may be transmitted via a telecommunications line.

[0026] The control unit 15 may execute an application installed on its own device (terminal device 10). The program installed on the terminal device 10 may cause the computer to function as the opening degree calculation system 1 according to this embodiment. A specific example of such an application is an application provided to the terminal device 10 as a dedicated application for the opening degree calculation system 1. Another specific example of such an application is a web browser application. Such an application may be pre-installed on the terminal device 10, or it may be downloaded each time a determination process is executed. For example, if it is implemented as a web browser application, the terminal device 10 may download and execute the application from a device specified by the web server (for example, the web server itself or another server) when the terminal device 10 connects to a specific web server. The control unit 15 operates according to the program of the application that is currently running.

[0027] The upstream acquisition means 151 acquires the pressure upstream of the control valve V. The upstream acquisition means 151 may acquire the upstream pressure by, for example, receiving the pressure measurement value measured by the upstream pressure sensor US1 via the network N. It is preferable that the pressure acquisition by the upstream acquisition means 151 is performed continuously while the boiler equipment B is in operation.

[0028] The downstream acquisition means 152 acquires the target pressure downstream of the control valve V. In this embodiment, the downstream target pressure is determined, for example, by input by the user via the input unit 12. The downstream acquisition means 152 may acquire the downstream target pressure, for example, by acquiring the information input by the user. It is preferable that the acquisition of the target pressure by the downstream acquisition means 152 is performed continuously while the boiler equipment B is in operation.

[0029] The flow rate measuring means 153 measures the flow rate downstream. In this embodiment, measuring the flow rate downstream may mean, for example, receiving a measured value of the flow rate downstream. For example, the flow rate measuring means 153 receives a current value, which is a measured value of the flow rate measured by the downstream flow rate sensor DS3, via the network N. The flow rate measuring means 153 may then obtain the flow rate downstream by appropriately calculating a flow rate value based on the current value thus obtained. It is preferable that the acquisition of flow rate by the flow rate measuring means 153 is performed continuously while the boiler equipment B is in operation.

[0030] The abnormality determination means 154 determines whether or not there is an abnormality in the flow rate measuring means 153. In this embodiment, an abnormality in the flow rate measuring means 153 indicates that the flow rate acquired by the flow rate measuring means 153 is abnormal. The abnormality determination means 154 may determine that the flow rate measuring means 153 is abnormal, for example, when the downstream flow sensor DS3 outputs an abnormal signal as described above. Alternatively, the abnormality determination means 154 may determine that the flow rate measuring means 153 is abnormal if the current value obtained by the flow rate measuring means 153 from the downstream flow sensor DS3 is outside a predetermined range, regardless of the abnormal signal. It is preferable that the determination by the abnormality determination means 154 is performed continuously while the boiler equipment B is in operation.

[0031] The flow rate determination means 155 determines whether the flow rate measured by the flow rate measuring means 153 exceeds a predetermined threshold. In this embodiment, the predetermined threshold may be determined, for example, by a user inputting it via the input unit 12. The flow rate determination means 155 may determine whether the flow rate exceeds the predetermined threshold by comparing the predetermined threshold determined by the user with the measured flow rate obtained by the flow rate measuring means 153 from the downstream flow sensor DS3. It is preferable that the determination by the flow rate determination means 155 is performed continuously while the boiler equipment B is in operation.

[0032] The CV value acquisition means 156 acquires the CV value corresponding to the current opening degree of the control valve V. The CV value used for controlling the control valve V is an intrinsic value determined from the flow path structure inside the control valve V, and indicates the flow rate corresponding to the opening degree of the control valve V. In this embodiment, the CV value is obtained, for example, by the following equation (1) or (2).

[0033] CV=Q(1+0.0013Tsh) / [0.138 {ΔP(P1+P2)} ^1 / 2 ] ; ΔP<0.5P1 … (1) CV=Q(1+0.0013Tsh) / 0.12P1 ;ΔP≧0.5P1 … (2) However, CV:CV value Q: under Flow rate on the flow side Tsh: Superheating degree (saturation temperature corresponding to upstream temperature - upstream pressure) P1: Upstream pressure P2: Downstream target pressure ΔP: Value of P1-P2 The CV value acquisition means 156, for example, in equation (1) or (2), under Flow-side flow sensor D S3 measured under The measured flow rate on the flow side may be used for Q, the saturated temperature corresponding to the upstream pressure acquired by the upstream acquisition means 151 may be used for Tsh, the measured upstream pressure acquired by the upstream acquisition means 151 may be used for P1, and the target downstream pressure acquired by the downstream acquisition means 152 may be used for P2.

[0034] The opening degree calculation means 157 calculates the opening degree of the control valve V based on the upstream pressure obtained by the upstream acquisition means 151, the downstream target pressure obtained by the downstream acquisition means 152, and the flow rate measured by the flow rate measurement means 153. It is preferable that the calculation of the opening degree of the control valve V by the opening degree calculation means 157 is performed continuously while the boiler equipment B is in operation. In this embodiment, the opening degree calculation means 157 may use the CV value calculated by the CV value acquisition means 156 to calculate the opening degree of the control valve V based on the following equation (3). Note that equation (3) may be used as a reference.

[0035] MV=25.434×ln(CV)-92.835 … (3) However, MV: Opening degree of control valve V (%) Figure 4 is a graph showing the relationship between the CV value and the opening degree of the control valve V. In Figure 4, the horizontal axis represents the CV value, and the vertical axis represents the opening degree (%) of the control valve V. Figure 4 is a graph corresponding to equation (3). That is, the opening degree of the control valve V is calculated based on the natural logarithm of the CV value. The opening degree calculation means 157 may calculate the opening degree of the control valve V based on the graph shown in Figure 4 or equation (3). Thus, in this embodiment, the valve opening degree calculated by equation (3) is used for feedforward control of the opening degree of the control valve V. Furthermore, the valve opening degree calculated by equation (3) may be used in reverse calculation of the CV value using equation (6) by the flow rate calculation means 158, which will be described later. Furthermore, equations (1) to (3) and the graph shown in Figure 4 may be stored in the memory unit 14, for example.

[0036] The flow rate calculation means 158 calculates the theoretical flow rate downstream based on the CV value obtained by the CV value acquisition means 156, the measured value of the upstream pressure obtained by the upstream acquisition means 151, and the target pressure of the downstream side obtained by the downstream acquisition means 152. It is preferable that the calculation of the theoretical flow rate by the flow rate calculation means 158 is performed continuously while the boiler equipment B is in operation. In this embodiment, the theoretical flow rate can be determined, for example, by equation (4) or (5) below.

[0037] TQ=CV×[0.138 {ΔP(P1+P2)} ^1 / 2 ] / (1+0.0013Tsh) *10^-3 ; ΔP<0.5P1 … (4) TQ=CV×0.12P1 / (1+0.0013Tsh)*10^-3 ;ΔP≧0.5P1 … (5) However, TQ: Theoretical flow rate CV: CV value Tsh: Superheating degree (saturation temperature corresponding to upstream temperature - upstream pressure) P1: Upstream pressure P2: Downstream target pressure ΔP: Value of P1-P2 The flow rate calculation means 158 may, for example, use the saturation temperature corresponding to the upstream pressure acquired by the upstream acquisition means 151 for Tsh in equation (4) or (5), use the measured value of the upstream pressure acquired by the upstream acquisition means 151 for P1, and use the downstream target pressure acquired by the downstream acquisition means 152 for P2. Furthermore, in this embodiment, the flow rate calculation means 158 uses the CV obtained by the following equation (6) as the CV value in equation (4) or (5).

[0038] CV =38.5×exp^(0.039×MV) … (6) However, MV: valve opening Figure 5 is a graph showing the relationship between the opening degree of the control valve V and the CV value. In Figure 5, the horizontal axis represents the opening degree (%) of the control valve V, and the vertical axis represents the CV value. Figure 5 is a graph corresponding to equation (6). That is, the CV value is determined based on the exponential function of the opening degree of the control valve V. Note that the MV (valve opening degree) in equation (6) may be the one calculated by the opening degree calculation means 157 using equation (3) described above. The flow rate calculation means 158 may calculate the theoretical flow rate based on the graph shown in Figure 5 or equations (4) to (6). Thus, in this embodiment, the CV value calculated by working backward from the valve opening degree using equation (6) is used by the normal determination means 159 described below to determine whether the control valve V is normal or not. Equations (4) to (6), and the graph shown in Figure 5, may be stored in the memory unit 14, for example.

[0039] The normal determination means 159 determines whether the control valve V is functioning normally based on the theoretical flow rate on the downstream side, which is the result of the flow rate calculation means 158, and the measured value of the downstream flow rate, which is the result of the flow rate measurement means 153. It is preferable that the determination by the normal determination means 159 is performed continuously while the boiler equipment B is in operation. In this embodiment, the normal determination means 159 compares the theoretical flow rate calculated by the flow rate calculation means 158 with the measured value of the downstream flow rate obtained by the flow rate measurement means 153. If the difference between these values ​​is within a predetermined threshold, the control valve V may be determined to be normal. If the difference between these values ​​exceeds the predetermined threshold, the control valve V may be determined to be abnormal. An abnormality in the control valve V may indicate, for example, that the control valve V has deteriorated. The predetermined threshold may be determined appropriately by the user, for example.

[0040] The first control means 15A performs feedforward control and feedback control of the control valve V based on the calculation result of the opening degree calculation means 157. Specifically, the first control means 15A controls the opening degree of the control valve V to the opening degree calculated by the opening degree calculation means 157 as described above. This control is feedforward control.

[0041] Here, the calculation of the opening degree of the control valve V by the opening degree calculation means 157 is performed based on the flow rate measured by the flow rate measurement means 153, as described above. In this case, if the flow rate measurement means 153 is malfunctioning, it becomes impossible to obtain an accurate downstream flow rate, and therefore the feedforward control by the first control means 15A described above cannot be performed. Therefore, the first control means 15A may switch between feedforward control of the control valve V and feedback control of the control valve V based on the determination result of the abnormality determination means 154. That is, for example, if the abnormality determination means 154 determines that the flow rate measuring means 153 is abnormal, the first control means 15A may stop controlling the opening degree of the control valve V by the feedforward control described above and perform feedback control.

[0042] Furthermore, if the flow rate of steam flowing inside the piping P is low, the accuracy of flow rate measurement by the flow rate measuring means 153, or in other words, the accuracy of flow rate measurement by the downstream flow rate sensor DS3, may decrease. In such cases, it becomes impossible to obtain an accurate downstream flow rate, and the feedforward control described above by the first control means 15A becomes impossible. Therefore, the first control means 15A may switch between feedforward control of the control valve V and feedback control of the control valve V based on the determination result of the flow rate determination means 155. That is, for example, if the flow rate determination means 155 determines that the flow rate measured by the flow rate measuring means 153 does not exceed a predetermined threshold, the first control means 15A may stop controlling the opening degree of the control valve V by the feedforward control described above and perform feedback control.

[0043] Furthermore, the first control means 15A may perform feedforward control of the control valve V based on the calculation result of the opening degree calculation means 157, as well as feedback control. In other words, the control of the opening degree of the control valve V may be performed simultaneously using the feedforward control described above and known feedback control.

[0044] In this embodiment, the feedback control of the opening degree of the control valve V by the first control means 15A may be, for example, a known PID control. Furthermore, the feedback control by the first control means 15A may be performed based on the downstream pressure. That is, the feedback control of the opening degree of the control valve V by the first control means 15A may be performed based on the downstream pressure inside the piping P measured by the downstream pressure sensor DS1. Specifically, for example, if the downstream pressure is set to a predetermined pressure, the first control means 15A may control the valve to open more when the downstream pressure falls below the predetermined pressure and to open less when the pressure rises above the predetermined pressure. Here, for example, if the opening degree of the control valve V is controlled by known feedback control alone, it is difficult to follow fluctuations in the target pressure downstream without delay. The opening degree calculation system 1 according to this embodiment contributes to being able to follow fluctuations in the target pressure without delay by performing feedforward control as described above.

[0045] The second control means 15B provides feedback control to the control valve V based on the actual pressure. In this embodiment, the actual pressure refers to the pressure on the downstream side inside the piping P, as measured by the downstream pressure sensor DS1. In this embodiment, the feedback control of the opening degree of the control valve V by the second control means 15B may be, for example, a known PID control. Furthermore, the feedback control by the second control means 15B may be based on the actual pressure downstream. Specifically, the feedback control of the opening degree of the control valve V by the second control means 15B may be based on the downstream pressure (actual pressure) inside the piping P measured by the downstream pressure sensor DS1.

[0046] Figure 6 shows a control block by the opening degree calculation system 1 according to an embodiment. The control logic shown in Figure 6 includes a first parameter Pm1, a second parameter Pm2, a third parameter Pm3, a first control block Ct1, a second control block Ct2, a third control block Ct3, a fourth control block Ct4, and a fifth control block Ct5. In this embodiment, the control logic shown in Figure 6 may be stored, for example, in the memory unit 14.

[0047] The first parameter Pm1 is a parameter used for feedforward control of the opening degree of the control valve V, which is performed by the first control means 15A. In other words, the first parameter Pm1 is a set of parameters used by the opening degree calculation means 157 to calculate the opening degree of the control valve V. Specifically, the first parameter Pm1 may include, for example, the upstream pressure acquired by the upstream acquisition means 151, the saturation temperature corresponding to the upstream pressure, the upstream steam temperature, the flow rate measured by the flow rate measuring means 153, the downstream target pressure acquired by the downstream acquisition means 152, and so on. As shown in Figure 6, information relating to the first parameter Pm1 may be transmitted to the first control block Ct1.

[0048] The second parameter Pm2 is a parameter used for feedback control of the opening degree of the control valve V, which is performed by the first control means 15A. That is, the second parameter Pm2 may include, for example, the downstream pressure inside the piping P measured by the downstream pressure sensor DS1. As shown in Figure 6, information relating to the second parameter Pm2 may be transmitted to the second control block Ct2. Alternatively, information relating to the second parameter Pm2 may be transmitted to the first control block Ct1.

[0049] The third parameter Pm3 is a parameter used for feedback control of the opening degree of the control valve V, which is performed by the second control means 15B. That is, the third parameter Pm3 may include, for example, the pressure inside the steam drum BD measured by the upstream pressure sensor US1. As shown in Figure 6, information relating to the third parameter Pm3 may be transmitted to the third control block Ct3. Alternatively, information relating to the third parameter Pm3 may be transmitted to the first control block Ct1.

[0050] The first control block Ct1 is a block for feedforward control of the opening degree of the control valve V by the first control means 15A. As described above, the first control block Ct1 receives the first parameter Pm1, the second parameter Pm2, and the third parameter Pm3, respectively. Based on each of the parameters thus received, the first control block Ct1 may output control information related to the feedforward control of the opening degree of the control valve V. The control information output by the first control block Ct1 is the opening degree of the control valve V, which is calculated by the opening degree calculation means 157 based on equations (1) to (3) above and the graph shown in Figure 4. In other words, the function of the first control block Ct1 may be guaranteed by the opening degree calculation means 157. As shown in Figure 6, the control information output in the first control block Ct1 may be transmitted to the fourth control block Ct4.

[0051] The second control block Ct2 is a block for feedback control of the opening degree of the control valve V by the first control means 15A. As described above, the second parameter Pm2 is transmitted to the second control block Ct2. Based on the second parameter Pm2 transmitted in this manner, the first control means 15A may output control information related to feedback control of the opening degree of the control valve V. As shown in Figure 6, the control information output in the second control block Ct2 may be transmitted to the fourth control block Ct4.

[0052] The third control block Ct3 is a block for feedback control of the opening degree of the control valve V by the second control means 15B. As described above, the third parameter Pm3 is transmitted to the third control block Ct3. Based on the third parameter Pm3 transmitted in this manner, the second control means 15B may output control information regarding feedback of the opening degree of the control valve V. As shown in Figure 6, the control information output in the third control block Ct3 may be transmitted to the fifth control block Ct5.

[0053] The fourth control block Ct4 receives control information related to feedforward control of the opening degree of the control valve V, which is output by the first control block Ct1, and control information related to feedback control of the opening degree of the control valve V, which is output by the second control block Ct2. The fourth control block Ct4 transmits this received control information to the fifth control block Ct5.

[0054] The fifth control block Ct5 transmits control information to the control valve V. The fifth control block Ct5 receives control information transmitted from the fourth control block Ct4, as well as control information output from the first control block Ct1 and the second control block Ct2, and control information output from the third control block Ct3. Then, the fifth control block Ct5 transmits either the control information transmitted from the third control block Ct3 or the control information transmitted from the fourth control block Ct4 to the control valve V. As a result, the control valve V operates and its opening degree is adjusted. In this embodiment, the fifth control block Ct5 may decide whether to transmit the control information to the control valve V from the control information transmitted from the third control block Ct3 or the control information transmitted from the fourth control block Ct4, as follows. In other words, the fifth control block Ct5 transmits control information sent from the fourth control block Ct4 to the control valve V when the pressure of the steam drum BD in boiler equipment B is in a normal state. Then, when the pressure of the steam drum BD in boiler equipment B drops below the normal state, the fifth control block Ct5 transmits control information sent from the third control block Ct3 to the control valve V. This allows the opening of the control valve V to be controlled with high precision by feedforward control and feedback control by the first control means 15A when the pressure of the steam drum BD is in a normal state, while maintaining the pressure of the steam drum BD by feedback control by the second control means 15B when the pressure of the steam drum BD falls below the normal state. In this embodiment, the fifth control block Ct5 may determine, for example, that the pressure in the steam drum BD has decreased as follows:

[0055] Here, under normal conditions, the pressure in the steam drum BD is higher than the downstream pressure inside the piping P. Therefore, under normal conditions, the opening degree of the control valve V related to the control information output by the third control block Ct3 is greater than the opening degree of the control valve V related to the control information output by the fourth control block Ct4. Conversely, when the pressure in the steam drum BD decreases, it is necessary to reduce the opening of the control valve V in order to suppress the pressure drop. Therefore, the control information output by the third control block Ct3 when the pressure in the steam drum BD decreases includes an instruction to reduce the opening of the control valve V. Based on the above, the fifth control block Ct5 may, for example, determine that the pressure in the steam drum BD has decreased below the normal state when the opening degree of the control valve V related to the control information output by the third control block Ct3 falls below the opening degree of the control valve V related to the control information output by the fourth control block Ct4, and transmit the control information sent from the third control block Ct3 to the control valve V.

[0056] The display control means 15C displays various information related to the control by the opening degree calculation system 1 of this embodiment on the display unit 13. The user may, for example, understand the status of the opening degree of the control valve V in the boiler equipment B by visually checking the various information displayed on the display unit 13. Alternatively, the user may adjust the parameters related to the control of the opening degree of the control valve V using the various information displayed on the display unit 13, or directly operate the opening degree of the control valve V.

[0057] The display control means 15C displays, for example, the opening degree calculated by the opening degree calculation means 157, along with the opening degree calculated by the feedback control means 15B, on the display unit 13. At this time, the display control means 15C may also display the opening degree of the control valve V calculated by the feedback control means 15B and the opening degree parameter on the display unit 13 in a comparable manner. Specifically, it is as follows. Figure 7 is Figure 1, which shows the result of the control adjustment of the feedback control of the opening degree of the control valve V. Figure 8 is the second figure showing the results of the control adjustment of the feedback control of the opening degree of the control valve V. Figure 9 is Figure 3, which shows the result of the control adjustment of the feedback control of the opening degree of the control valve V. The control adjustment results shown in Figures 7 to 9 are graphs with time (s) on the horizontal axis and the opening degree (%) of the control valve V on the vertical axis. The control adjustments in Figures 7 to 9 show the change in the opening degree of the control valve V when a simulated load is applied to the control of the control valve V at time T1 (shown on the horizontal axis), and the opening degree of the control valve V is controlled by feedback. Note that the control adjustments in Figures 7 to 9 are the results of PID control.

[0058] Figures 7 to 9 show, respectively, a first curve C1 representing the ideal change in the opening degree of the control valve V over time, and a second curve C2 representing the result of the control adjustment of the feedback control. The ideal change in the opening degree of the control valve V related to the first curve may be the result of the opening degree calculation means 157. That is, the calculation result of the opening degree calculation means 157 may be used not only for controlling the opening degree of the control valve V, but also for adjusting the control of the opening degree of the control valve V.

[0059] As shown in Figure 7, the result of the control adjustment related to the second curve C2 shows an overshoot relative to the first curve C1. Based on this result, the user may, for example, weaken the P element in the PID control related to the control adjustment. As shown in Figure 8, the control adjustment result for the second curve C2 is offset from the first curve C1, indicating that convergence is taking a long time. Based on this result, the user may, for example, strengthen the I element in the PID control related to the control adjustment. As shown in Figure 9, the result of the control adjustment related to the second curve C2 shows that it is hunting relative to the first curve C1. Based on this result, the user may, for example, add a D element, which is an element that suppresses hunting, to the PID control related to the control adjustment.

[0060] Furthermore, the display control means 15C may, as appropriate, display an operation screen on the display unit 13 that allows the user to control the opening degree of the control valve V using the opening degree calculation system 1. Specifically, this is as follows. Figure 10 shows an example of the control screen for adjusting the opening of the control valve V. The operation screen shown in Figure 10 is used by the user to directly control the opening degree of the control valve V. The user, for example, uses the input unit 12 to select a screen displayed on the operation screen or to input a numerical value. The terminal device 10 may also accept input from the user, allowing the user to directly control the opening degree of the control valve V. The operation screen shown in Figure 10 includes a pressure image I1, a target pressure image I2, a feedback opening image I3, a feedforward opening image I4, a pressure scale image I5, an MV value image I6, an operation switching image I7, a controller selection image I8, a detailed setting image I9, a control mode switching switch IA, and a manual operation image IB.

[0061] Pressure image I1 is an image showing the measured pressure (MPa) on the downstream side. Pressure image I1 may display, for example, the measured value of the downstream pressure sensor DS1. The target pressure image I2 is an image showing the target pressure (MPa) on the downstream side. The target pressure image I2 may display, for example, a numerical value entered by the user using the input unit 12.

[0062] The feedback opening image I3 is an image showing the opening degree (%) of the control valve V, obtained by feedback control. The feedback opening image I3 may display, for example, the opening degree based on the control information output by the second control block Ct2 or the third control block Ct3. The feedforward opening image I4 is an image showing the opening degree (%) of the control valve V, acquired by feedforward control. The feedforward opening image I4 may display, for example, the opening degree based on the control information output by the first parameter Pm1.

[0063] Pressure scale image I5 is an image that displays the measured pressure values ​​related to pressure image I1 using a scale. Image I6 of the MV value is an image showing the MV value in feedback control with a scale. In the example shown in Figure 10, the MV value is 80%. Operation switching image I7 shows whether the opening degree of the control valve V is controlled manually or automatically. The user may visually check operation switching image I7 to confirm whether the opening degree of the control valve V is controlled manually or automatically.

[0064] The controller selection image I8 is an image showing the controller used to control the downstream pressure. In the example shown in Figure 10, the "PICA-ST02" controller is displayed on the left side of the secondary pressure controller operation screen, and the "PICA-ST03" controller is displayed on the right side. The user may, for example, use the input unit 12 to select either "PICA-ST02" or "PICA-ST03" and set the controller to be used to control the downstream pressure as appropriate. When the user selects either "PICA-ST02" or "PICA-ST03" using the controller selection image I8, the display control means 15C may illuminate the controller selection image I8 corresponding to the selected one, or it may display the controller selection image I8 corresponding to the other one in grayscale.

[0065] Detailed settings image I9 is ​​a button that opens a screen for making detailed settings related to the control of the opening degree of the control valve V. The user may open the screen for making detailed settings by clicking or tapping detailed settings image I9. Figure 11 shows an example of the detailed setting screen for the opening degree of the control valve V. The detailed settings screen shown in Figure 11 may be displayed by selecting the detailed settings image I9 on the screen shown in Figure 10 by clicking or tapping. The user may, for example, make detailed settings regarding the control of the opening degree of the control valve V by appropriately entering various numerical values ​​using the input unit 12 into the fields corresponding to various parameters such as "P", "I", and "D" shown on the detailed settings screen shown in Figure 11. Furthermore, when the detailed settings screen shown in Figure 11 is displayed, a trend graph displaying the pressure values, MV values, etc., related to each of the images described above may also be displayed on the display unit 13.

[0066] The control mode selector switch IA is a button that selects whether to control the opening degree of the control valve V manually or automatically. The user may switch the control of the opening degree of the control valve V between manual and automatic by clicking or tapping the control mode selector switch IA. Manual operation image IB is an image for the user to directly input the opening degree (%) of the control valve V. The user may also change the opening degree (%) of the control valve V by clicking the arrow-shaped button IBa included in manual operation image IB.

[0067] Furthermore, the display control means 15C may display the theoretical flow rate, which is the result of the flow rate calculation means 158, and the actual flow rate, which is the result of the flow rate measurement means 153, on the display unit 13 in a comparable manner. This may help the user to more easily notice abnormalities in the flow meter. Figure 12 is a graph that displays theoretical flow rates and actual flow rates for comparison. In Figure 12, the horizontal axis represents time, and the vertical axis represents flow rate. In the example shown in Figure 12, the changes in the theoretical and measured flow rates are similar, indicating that the measured value exceeds the theoretical value.

[0068] The alarm issuing means 15D issues an alarm when the difference between the calculation result of the flow rate calculation means 158 and the measurement result of the flow rate measurement means 153 exceeds a predetermined threshold. The alarm issued by the alarm issuing means 15D may be done, for example, by displaying an alarm image on the display unit 13, or by emitting a buzzer sound from the speaker. The opening degree calculation system 1 according to this embodiment is configured with the above-described components.

[0069] (Opening calculation method) Next, the opening degree calculation method according to this embodiment will be described. The opening degree calculation method according to this embodiment is a method for controlling the opening degree of the control valve V using the opening degree calculation system 1 described above. Figure 13 shows a flowchart of the opening degree calculation method according to the embodiment. As shown in Figure 13, the opening degree calculation method according to this embodiment includes an upstream acquisition step St1, a downstream acquisition step St2, a flow rate measurement step St3, an abnormality determination step St4, a flow rate determination step St5, a CV value acquisition step ST6, an opening degree calculation step St7, a flow rate calculation step St8, a normal determination step St9, a display control step StA, a control step StB, an alarm activation step StC, and a confirmation step StD.

[0070] The upstream acquisition step St1 is a step in which the upstream acquisition means 151 acquires the pressure upstream with reference to the control valve V as described above. The downstream acquisition step St2 is a step in which the downstream acquisition means 152 acquires the target pressure downstream of the control valve V as described above. The flow rate measurement step St3 is a step in which the flow rate measurement means 153 measures the flow rate downstream as described above.

[0071] The abnormality determination step St4 is a step in which the abnormality determination means 154 determines whether or not there is an abnormality in the flow rate measuring means 153 as described above. The flow rate determination step St5 is a step in which the flow rate determination means 155 determines whether the flow rate measured by the flow rate measuring means 153 as described above exceeds a predetermined threshold. Step ST6 for acquiring the CV value is a step in which the CV value acquisition means 156 acquires the CV value corresponding to the current opening degree of the control valve V as described above.

[0072] The opening degree calculation step St7 is a step in which the opening degree calculation means 157 calculates the opening degree of the control valve V based on the upstream pressure obtained by the upstream acquisition step St1, the downstream target pressure obtained by the downstream acquisition step St2, and the flow rate measured by the flow rate measurement step St3, as described above. The flow rate calculation step St8 is a step in which the flow rate calculation means 158 calculates the theoretical flow rate as described above. The normal determination step St9 is a step in which the normal determination means 159 determines whether or not the control valve V is normal as described above.

[0073] The display control step StA is a step in which the display control means 15C displays various information related to the control by the opening degree calculation system 1 of this embodiment on the display unit 13, as described above. In the display control step StA, the user may, for example, visually check the various information displayed on the display unit 13 to understand the status of the opening degree of the control valve V in the boiler equipment B. Alternatively, in the display control step StA, the user may use the various information displayed on the display unit 13 to adjust the parameters related to the control of the opening degree of the control valve V, or directly operate the opening degree of the control valve V.

[0074] The control step StB is a step in which the first control means 15A and the second control means 15B control the opening degree of the control valve V by feedforward control or feedback control as described above. In control step StB, the first control means 15A and the second control means 15B may control the opening degree of the control valve V by, for example, the control logic shown in Figure 6. Furthermore, in control step StB, the first control means 15A may switch between feedforward control of the control valve V and feedback control of the control valve V based on the determination result of the abnormality determination means 154. Furthermore, in control step StB, the first control means 15A may switch between feedforward control of the control valve V and feedback control of the control valve V based on the determination result of the flow rate determination means 155. Furthermore, the first control means 15A may perform feedforward control of the control valve V based on the calculation result of the opening degree calculation means 157, as well as feedback control. Furthermore, in control step StB, the second control means 15B may provide feedback control to the control valve V based on the actual pressure. Furthermore, if the user adjusts the parameters related to controlling the opening degree of the control valve V in the display control step StA, or directly manipulates the opening degree of the control valve V, the first control means 15A may control the opening degree of the control valve V based on the user's operation.

[0075] The alarm activation step StC is a step in which the alarm activation means 15D activates an alarm when the difference between the calculation result of the flow rate calculation means 158 and the measurement result of the flow rate measurement means 153 exceeds a predetermined threshold, as described above. In the alarm activation step StC, the alarm activation means 15D checks whether the difference exceeds the predetermined threshold. The alarm activation means 15D activates an alarm only if the difference exceeds the predetermined threshold, and does not activate an alarm if it does not exceed the predetermined threshold.

[0076] The confirmation step StD is a step to check whether boiler equipment B is in operation or not. If boiler equipment B is in operation (StD: YES), the flow of the opening degree calculation method returns to the upstream acquisition step St1. If boiler equipment B has stopped operating (StD: NO), the flow of the opening degree calculation method ends. The opening degree calculation method according to this embodiment is implemented as described above. Note that the opening degree calculation method according to this embodiment may be performed, for example, during the trial run of the control valve V.

[0077] Figure 14 is a schematic diagram showing an example of the hardware configuration of the information processing device 90 applied to this embodiment. The information processing device 90 comprises a processor 91, main memory 92, communication interface 93, auxiliary storage device 94, input / output interface 95, and internal bus 96. The processor 91, main memory 92, communication interface 93, auxiliary storage device 94, and input / output interface 95 are connected to each other via the internal bus 96 so as to be able to communicate with each other. The information processing device 90 may be applied to, for example, a terminal device 10. In this case, for example, the communication unit 11 may be configured using the communication interface 93. For example, the storage unit 14 may be configured using the auxiliary storage device 94. Furthermore, the control unit 15 may be configured using the processor 91 and the main memory 92.

[0078] As described above, according to the opening degree calculation system 1 of this embodiment, the opening degree of the control valve V is calculated by the opening degree calculation means 157 based on the upstream pressure acquired by the upstream acquisition means 151, the downstream target pressure acquired by the downstream acquisition means 152, and the downstream flow rate measured by the flow rate measurement means 153. This makes it possible to calculate the opening degree of the control valve V using the target pressure and flow rate downstream of the control valve V, which is the reference. Therefore, the opening degree of the control valve V can be calculated appropriately according to the flow rate and pressure obtained downstream of the reference.

[0079] Furthermore, the system includes a first control means 15A that feedforward controls the control valve V based on the calculation results of the opening degree calculation means 157, and also performs feedback control. This allows, for example, the opening degree of the control valve V to be determined based on the flow rate and pressure obtained downstream of the reference by feedforward control of the control valve V by the first control means 15A. Then, the opening degree of the control valve V can be finely adjusted by feedback control of the control valve V by the first control means 15A. Therefore, since only fine adjustment of the opening degree of the control valve V is required by feedback control, feedback control can be made easier. In addition, the opening degree of the control valve V can be controlled with higher precision. Specifically, for example, by performing feedforward control, it is possible to follow fluctuations in the target pressure without delay.

[0080] Furthermore, the abnormality determination means 154 determines whether or not there is an abnormality in the flow rate measurement means 153. Based on the determination result of the abnormality determination means 154, the first control means 15A switches between feedforward control of the control valve V and feedback control of the control valve V. This allows the control valve V to be appropriately switched between feedforward control and feedback control depending on whether or not there is an abnormality in the flow rate measurement means 153.

[0081] In this case, the accuracy of flow rate measurement by the flow rate measuring means 153 may decrease when the flow rate is low. Therefore, the flow rate determination means 155 determines whether the flow rate measured by the flow rate measuring means 153 exceeds a predetermined threshold. This makes it possible to determine whether the accuracy of the flow rate measurement by the flow rate measuring means 153 can be guaranteed. The first control means 15A then switches between feedforward control of the control valve V and feedback control of the control valve V based on the determination result of the flow rate determination means 155. This allows the control valve V to be appropriately switched between feedforward control and feedback control depending, for example, whether the accuracy of the flow rate measurement by the flow rate measurement means 153 can be guaranteed.

[0082] Furthermore, the first control means 15A performs feedforward control and feedback control of the control valve V based on the calculation result of the opening degree calculation means 157. By performing feedforward control and feedback control of the control valve V simultaneously in this way, the opening degree of the control valve V can be controlled with higher precision.

[0083] Furthermore, the system includes a second control means 15B that provides feedback control of the control valve V based on the actual pressure. The display control means 15C displays the opening degree parameter, which is calculated by the opening degree calculation means 157, along with the opening degree obtained by the feedback control by the second control means 15B, on the display unit 13. This makes it easier for the user to understand information regarding the control of the opening degree of the control valve V.

[0084] Furthermore, the display control means 15C displays on the display unit 13, in a comparable manner, the opening degree of the control valve V determined by feedback control by the second control means 15B and the opening degree parameter indicating the opening degree of the control valve V calculated by the opening degree calculation means 157. This makes it easier for the user to appropriately set the opening degree of the control valve V while comparing this information.

[0085] Furthermore, the CV value acquisition means 156 acquires the CV value corresponding to the current opening degree of the control valve V. The flow rate calculation means 158 calculates the theoretical flow rate based on the acquisition results from the CV value acquisition means 156, the acquisition results from the upstream acquisition means 151, and the acquisition results from the downstream acquisition means 152. Then, the normality determination means 159 determines whether the control valve V is functioning normally based on the calculation results from the flow rate calculation means 158 and the measurement results from the flow rate measurement means 153. This makes it possible to diagnose deterioration of the control valve V.

[0086] Furthermore, the display control means 15C displays the calculation result of the flow rate calculation means 158 and the measurement result of the flow rate measurement means 153 on the display unit 13 in a comparable manner. In addition, the alarm means 15D issues an alarm when the difference between the calculation result of the flow rate calculation means 158 and the measurement result of the flow rate measurement means 153 exceeds a predetermined threshold. This makes it easier for the user to compare the theoretical flow rate with the actual flow rate. Therefore, for example, it makes it easier for the user to notice abnormalities in the flow meter.

[0087] Furthermore, according to the opening degree calculation method of this embodiment, the opening degree of the control valve V is calculated in the opening degree calculation step based on the upstream pressure obtained in the upstream acquisition step, the downstream target pressure obtained in the downstream acquisition step, and the downstream flow rate measured in the flow rate measurement step. This makes it possible to calculate the opening degree of the control valve V using the target pressure and flow rate downstream of the control valve V, which is the reference. Therefore, the opening degree of the control valve V can be calculated appropriately according to the flow rate and pressure obtained downstream of the reference.

[0088] Furthermore, the opening degree calculation method described in this disclosure will be performed during trial operation. This will ensure that the opening degree of the control valve V can be reliably calculated after the equipment equipped with the control valve V has officially started operation.

[0089] The technical scope of this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of this disclosure. For example, in controlling the opening degree of the control valve V described above, a target flow rate may be used instead of a target pressure. That is, the opening degree of the control valve V may be controlled to match the flow rate in the piping P to a predetermined flow rate. In this way, the above control method can be applied not only to pressure control but also to the control valve V for flow rate control. Furthermore, the opening degree calculation system 1 does not need to include an abnormality determination means 154, nor does it need to include a flow rate determination means 155, nor does it need to include a second control means 15B. Furthermore, although the above-described embodiment explained that the second control means 15B provides feedback control of the control valve V based on the pressure on the downstream side inside the pipe P, the control valve V may also be provided feedback control based on the pressure on the upstream side inside the pipe P in order to prevent the pressure on the upstream side inside the pipe P from falling below a predetermined pressure.

[0090] Furthermore, it is possible to replace the components in the above embodiments with well-known components as appropriate, without departing from the spirit of this disclosure, and the above-described modifications may be combined as appropriate.

[0091] (Note) The opening degree calculation system, opening degree calculation method, and program according to the above embodiment can be understood, for example, as follows.

[0092] <1> An opening degree calculation system according to one aspect of the present disclosure is characterized by comprising: an upstream acquisition means for acquiring the pressure on the upstream side with respect to the control valve; a downstream acquisition means for acquiring a target pressure on the downstream side with respect to the control valve; a flow rate measuring means for measuring the flow rate on the downstream side; and an opening degree calculation means for calculating the opening degree of the control valve based on the upstream pressure acquired by the upstream acquisition means, the target pressure on the downstream side acquired by the downstream acquisition means, and the flow rate measured by the flow rate measuring means.

[0093] According to the above-described valve opening calculation system, the valve opening is calculated by the valve opening calculation means based on the upstream pressure acquired by the upstream acquisition means, the downstream target pressure acquired by the downstream acquisition means, and the downstream flow rate measured by the flow rate measurement means. This allows the valve opening to be calculated using the target pressure and flow rate downstream of the reference valve, and therefore, the valve opening can be calculated appropriately according to the flow rate and pressure required downstream of the reference.

[0094] <2> the above <1> The opening degree calculation system may further include a first control means that feedforward controls and feedback controls the control valve based on the calculation result of the opening degree calculation means.

[0095] Furthermore, the system includes a first control means that performs feedforward control and feedback control of the control valve based on the calculation result of the opening degree calculation means. This allows, for example, the opening degree of the control valve to be determined based on the flow rate and pressure obtained downstream of the reference by feedforward control of the control valve by the first control means. Then, the opening degree of the control valve can be finely adjusted by feedback control of the control valve by the first control means. Therefore, since only fine adjustment of the opening degree of the control valve is required by feedback control, feedback control can be made easier. In addition, the opening degree of the control valve can be controlled with higher precision. Specifically, for example, by performing feedforward control, it is possible to follow fluctuations in the target pressure without delay.

[0096] <3> the above <2> The opening degree calculation system may further include an abnormality determination means for determining whether or not there is an abnormality in the flow rate measuring means, and the first control means may adopt a configuration characterized by switching whether to feedforward control the control valve or feedback control the control valve based on the determination result of the abnormality determination means.

[0097] Furthermore, the abnormality detection means determines whether or not there is an abnormality in the flow rate measuring means. Based on the determination result of the abnormality detection means, the first control means switches between feedforward control of the control valve and feedback control of the control valve. This allows the control valve to be appropriately switched between feedforward control and feedback control depending on whether or not there is an abnormality in the flow rate measuring means.

[0098] <4> the above <2> or <3> The opening degree calculation system may further include a flow rate determination means that determines whether the flow rate measured by the flow rate measuring means exceeds a predetermined threshold, and the first control means may switch between feedforward control of the control valve and feedback control of the control valve based on the determination result of the flow rate determination means.

[0099] In this case, the accuracy of flow rate measurement by the flow rate measuring device may decrease when the flow rate is low. Therefore, the flow rate determination means determines whether the flow rate measured by the flow rate measurement means exceeds a predetermined threshold. This makes it possible to determine whether the accuracy of the flow rate measurement by the flow rate measurement means can be guaranteed. The first control means then switches between feedforward control and feedback control of the control valve based on the determination result of the flow rate determination means. This allows the control valve to be appropriately switched between feedforward control and feedback control depending, for example, whether the accuracy of flow rate measurement by the flow rate measuring means can be guaranteed.

[0100] <5> the above <2> from <4> In an opening degree calculation system according to any one of the above embodiments, the first control means may be configured to perform both feedforward control and feedback control of the control valve based on the calculation result of the opening degree calculation means.

[0101] Furthermore, the first control means performs feedforward control and feedback control of the control valve based on the calculation result of the opening degree calculation means. By performing feedforward control and feedback control of the control valve simultaneously in this way, the opening degree of the control valve can be controlled with higher precision.

[0102] <6> the above <1> from <5> An opening degree calculation system according to any one of the embodiments may further include a second control means for feedback-controlling the control valve based on the actual pressure, and a display control means for displaying an opening degree parameter on a display unit that indicates the opening degree calculated by the opening degree calculation means, along with the opening degree obtained by the feedback control by the second control means.

[0103] Furthermore, the system includes a second control means that provides feedback control of the control valve based on the actual pressure. The display control means displays the opening degree parameter, which is calculated by the opening degree calculation means, along with the opening degree obtained by the feedback control in the second control means, on the display unit. This makes it easier for the user to understand information regarding the control of the opening degree of the control valve.

[0104] <7> the above <6> In the opening degree calculation system relating to the above, the display control means may be configured to display the opening degree obtained by feedback control in the second control means and the opening degree parameter on the display unit in a comparable manner.

[0105] Furthermore, the display control means displays the opening degree of the control valve determined by feedback control in the second control means and the opening degree parameter indicating the opening degree of the control valve calculated by the opening degree calculation means, in a comparable manner on the display unit. This makes it easier for the user to appropriately set the opening degree of the control valve while comparing this information.

[0106] <8> the above <1> from <7> An opening degree calculation system according to any one of the embodiments may further include: a CV value acquisition means for acquiring a CV value corresponding to the current opening degree of the control valve; a flow rate calculation means for calculating a theoretical flow rate based on the acquisition result of the CV value acquisition means, the acquisition result of the upstream acquisition means, and the acquisition result of the downstream acquisition means; and a normal determination means for determining whether the control valve is functioning normally based on the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means.

[0107] Furthermore, the CV value acquisition means acquires the CV value corresponding to the current opening degree of the control valve. The flow rate calculation means calculates the theoretical flow rate based on the acquisition results from the CV value acquisition means, the acquisition results from the upstream acquisition means, and the acquisition results from the downstream acquisition means. Then, the normal determination means determines whether the control valve is functioning normally based on the calculation results from the flow rate calculation means and the measurement results from the flow rate measurement means. This makes it possible to diagnose deterioration of the control valve.

[0108] <9> the above <8> The opening degree calculation system may further include a display control means that displays the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means on a display unit in a comparable manner, and an alarm means that issues an alarm when the difference between the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means exceeds a predetermined threshold.

[0109] Furthermore, the display control means displays the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means on the display unit in a comparable manner. In addition, the alarm means issues an alarm when the difference between the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means exceeds a predetermined threshold. This makes it easier for the user to compare the theoretical flow rate with the actual flow rate. Therefore, for example, it makes it easier for the user to notice abnormalities in the flow meter.

[0110] <10> An opening degree calculation method according to one aspect of the present disclosure is characterized by comprising: an upstream acquisition step of acquiring the pressure on the upstream side with respect to the control valve; a downstream acquisition step of acquiring a target pressure on the downstream side with respect to the control valve; a flow rate measurement step of measuring the flow rate on the downstream side; and an opening degree calculation step of calculating the opening degree of the control valve based on the upstream pressure acquired by the upstream acquisition step, the target pressure on the downstream side acquired by the downstream acquisition step, and the flow rate measured by the flow rate measurement step.

[0111] According to the above method for calculating the opening degree, the opening degree of the control valve is calculated in the opening degree calculation step based on the upstream pressure obtained in the upstream acquisition step, the downstream target pressure obtained in the downstream acquisition step, and the downstream flow rate measured in the flow rate measurement step. This makes it possible to calculate the opening degree of the control valve using the target pressure and flow rate downstream of the control valve, which is the reference point. Therefore, the opening degree of the control valve can be appropriately calculated according to the flow rate and pressure required downstream of the reference point.

[0112] <11> the above <10> The method for calculating the degree of opening may be configured such that the method for calculating the degree of opening according to this disclosure is performed during trial operation.

[0113] Furthermore, the opening degree calculation method described in this disclosure will be performed during trial operation. This will ensure that the opening degree of the control valve can be reliably calculated after the equipment equipped with the control valve has officially started operation.

[0114] <12> A program relating to one aspect of this disclosure controls a computer as described above. <1> from <9> It is characterized by functioning as an opening degree calculation system according to any one of the following embodiments. [Explanation of Symbols]

[0115] 1. Opening degree calculation system 10 Terminal devices 11 Communications Department 12 Input section 13 Display section 14 Storage section 15 Control Unit 151 Upstream acquisition means 152 Downstream acquisition means 153 Flow rate measuring means 154 Abnormality determination means 155 Flow rate determination means 156 Means for obtaining CV values 157 Opening degree calculation means 158 Flow rate calculation means 159 Normality determination means 15A First control means 15B Second control means 15C Display control means 15D Alert means BD Steam Drum CL control logic N Network P piping V control valve

Claims

1. An upstream pressure acquisition means that acquires the pressure on the upstream side with respect to the control valve, A downstream acquisition means for acquiring a target pressure downstream of the aforementioned control valve, A flow rate measuring means for measuring the flow rate on the downstream side, An opening degree calculation means for calculating the opening degree of the control valve based on the upstream pressure obtained by the upstream acquisition means, the downstream target pressure obtained by the downstream acquisition means, and the flow rate measured by the flow rate measurement means, An opening degree calculation system characterized by comprising the following features.

2. A first control means that feedforward controls and feedback controls the control valve based on the calculation result of the opening degree calculation means. The opening degree calculation system according to claim 1, further comprising the following:

3. An abnormality determination means for determining whether or not there is an abnormality in the flow rate measuring means, Furthermore, The first control means switches whether to feedforward control the control valve or feedback control the control valve based on the determination result of the abnormality determination means. The opening degree calculation system according to feature 2.

4. A flow rate determination means that determines whether the flow rate measured by the flow rate measuring means exceeds a predetermined threshold, Furthermore, The first control means switches whether to feedforward control the control valve or feedback control the control valve based on the determination result of the flow rate determination means. The opening degree calculation system according to feature 2.

5. The first control means controls the control valve with feedforward control and feedback control based on the calculation result of the opening degree calculation means. The opening degree calculation system according to feature 2.

6. A second control means that provides feedback control of the control valve based on the actual pressure, Furthermore, A display control means that displays on the display unit the opening degree parameter, which indicates the opening degree calculated by the opening degree calculation means, along with the opening degree calculated by the feedback control by the second control means. The opening degree calculation system according to any one of claims 1 to 5, further comprising the above.

7. The display control means displays the opening degree obtained by feedback control in the second control means and the opening degree parameter on the display unit in a comparable manner. The opening degree calculation system according to feature 6.

8. A means for acquiring a CV value corresponding to the current opening degree of the control valve, A flow rate calculation means calculates a theoretical flow rate based on the acquisition results of the CV value acquisition means, the acquisition results of the upstream acquisition means, and the acquisition results of the downstream acquisition means. A normal determination means that determines whether the control valve is functioning normally based on the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means, The opening degree calculation system according to any one of claims 1 to 5, further comprising the above.

9. A display control means that displays the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means on a display unit in a comparable manner, An alarm is issued when the difference between the calculation result of the flow rate calculation means and the measurement result of the flow rate measurement means exceeds a predetermined threshold. The opening degree calculation system according to claim 8, further comprising the following:

10. An upstream pressure acquisition step is performed to obtain the pressure on the upstream side with the control valve as the reference point. A downstream acquisition step to acquire a target pressure downstream of the control valve, A flow rate measurement step for measuring the flow rate on the downstream side, An opening degree calculation step for calculating the opening degree of the control valve based on the upstream pressure obtained by the upstream acquisition step, the downstream target pressure obtained by the downstream acquisition step, and the flow rate measured by the flow rate measurement step, A method for calculating the degree of opening, characterized by comprising the following features.

11. The above method for calculating the opening degree is performed during trial operation. The method for calculating the degree of opening according to feature 10.

12. The computer is made to function as the opening degree calculation system according to any one of claims 1 to 5. A program characterized by the following features.

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