Coordinated control system and method for condensate system in power plant based on feedforward compensation

Abstract

The present invention provides a coordinated control system and method for a condensate system of a power plant based on feedforward compensation, wherein the first feedforward controller is constructed using the measured value of the condensate flow rate as a feedforward signal for hot well water level control; the second feedforward controller is constructed using the measured value of the condensate pressure as a decoupling control signal for deaerator water level control; and the third feedforward controller is constructed using the measured value of the deaerator water level as a decoupling control signal for condensate pressure control. The present invention solves the control problem of independent control of the three sub-loops and poor stability of the whole system in the traditional control scheme through the organic coordinated automatic control of the three control sub-loops of hot well water level, deaerator water level and condensate pressure in the condensate system, and realizes that the hot well water level, deaerator water level and condensate pressure control loops quickly reach a balance when the unit load changes rapidly and frequently, thereby enhancing the robustness of the whole condensate control system and meeting the full-condition operation control needs of the unit.

Description

Technical Field

[0001] The invention relates to the technical field of condensate system control of power plants, and in particular designs a condensate system coordinated control system and method for power plants based on feedforward compensation. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] The main function of the condensate system of a power plant is to transport the condensate in the condenser hot well to the deaerator through the condensate pump and the deaerator water supply regulating valve. The condensate system control system mainly includes three control sub-loops: condenser hot well water level, deaerator water level control, and condensate pressure control. Among them, the condenser hot well water level is achieved by adjusting the make-up water flow entering the condenser hot well by the make-up water regulating valve; when the unit is under high load and the condensate pump inverter is in normal state, the deaerator water level is achieved by controlling the condensate pump inverter to adjust the condensate flow entering the deaerator. At this time, the deaerator water supply regulating valve is responsible for controlling the condensate pressure; when the unit is under low load or the condensate pump inverter fails, the deaerator water supply regulating valve adjusts the condensate flow to control the deaerator water level, and the condensate pump controls the condensate pressure.

[0004] During the control process of the condensate system of the power plant, it was found that in the process of adjusting the condensate flow to control the deaerator water level, the deaerator water level control and the hot well water level control are related. When the condensate flow changes, the hot well water level will also fluctuate. The condensate flow affects the deaerator water level and the condenser hot well water level at the same time. In addition, during the control process of the condensate system, the condensate flow and condensate pressure also affect each other, and there is also a serious coupling effect between the deaerator water level control and the condensate pressure control. At present, in the traditional condensate system control scheme, the three control sub-loops of the condenser hot well water level, deaerator water level and condensate pressure control are all independently controlled, and the decoupling control between the control sub-loops is not considered. When the unit load changes rapidly, the hot well water level, deaerator water level and condensate pressure often fluctuate greatly at the same time, resulting in control lag and overshoot, and the robustness and stability of the condensate control system are poor. The traditional condensate system control scheme is obviously unable to meet the full-condition control requirements of large and frequent unit load changes. Summary of the invention

[0005] In order to address the deficiencies in the prior art, the present invention provides a coordinated control system and method for a condensate system in a power plant based on feedforward compensation. Through the organic coordinated automatic control of the three control sub-loops of the hot well water level, deaerator water level and condensate pressure in the condensate system, the control problem of independent control of the three sub-loops and poor stability of the entire system in the traditional control scheme is solved. When the unit load changes rapidly and frequently, the hot well water level, deaerator water level and condensate pressure control loops can quickly reach a balance, thereby enhancing the robustness of the entire condensate control system and meeting the unit's full operating condition operation control needs.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides a coordinated control system for a condensate system of a power plant based on feedforward compensation.

[0008] A coordinated control system for a condensate system of a power plant based on feedforward compensation, comprising:

[0009] The first condenser hot well water level controller is used to receive the hot well water level set value and the hot well water level measured value, the input end of the first feedforward controller is used to receive the condensate flow measured value, the output end of the first feedforward controller and the output end of the first hot well water level controller are respectively connected to the input end of the first adder, and the output end of the first adder is connected to the input end of the condenser hot well water replenishment regulating valve control circuit;

[0010] The input end of the first deaerator water level controller is used to receive the deaerator water level setting value and the deaerator water level actual value, and the input end of the first condensate pressure controller is used to receive the condensate pressure setting value and the condensate pressure actual value;

[0011] The input end of the second adder is used to receive the output signal of the first deaerator water level controller and the measured value of the feed water flow rate, the output end of the second adder is connected to the positive input end of the first condensate flow controller, and the negative input end of the first condensate flow controller is used to receive the condensate flow signal;

[0012] The input end of the second feedforward controller is used to receive the measured value of the condensate pressure, and the output end of the second feedforward controller and the output end of the first condensate flow controller are respectively connected to two input ends of the third adder;

[0013] The input end of the third feedforward controller is used to receive the measured value of the deaerator water level, and the output end of the third feedforward controller and the output end of the first condensate pressure controller are respectively connected to two input ends of the fourth adder;

[0014] The output end of the third adder and the output end of the fourth adder are respectively connected to the two input ends of the first analog switching switch, the judgment signal that the unit load is higher than the set value is connected to the trigger signal input end of the first analog switching switch, and the output end of the first analog switching switch is connected to the access end of the condensate pump inverter control circuit.

[0015] Further, the input end of the second deaerator water level controller is used to receive the deaerator water level setting value and the deaerator water level actual value, and the input end of the second condensate pressure controller is used to receive the condensate pressure setting value and the condensate pressure actual value;

[0016] The input end of the fifth adder is used to receive the output signal of the second deaerator water level controller and the measured value of the feed water flow rate, the output end of the fifth adder is connected to the positive input end of the second condensate flow controller, and the negative input end of the second condensate flow controller is used to receive the condensate flow signal;

[0017] The input end of the fourth feedforward controller is used to receive the measured value of the condensate pressure, and the output end of the fourth feedforward controller and the output end of the second condensate flow controller are respectively connected to the two input ends of the sixth adder;

[0018] The input end of the fifth feedforward controller is used to receive the measured value of the deaerator water level, and the output end of the fifth feedforward controller and the output end of the second condensate pressure controller are respectively connected to the two input ends of the seventh adder;

[0019] The output end of the sixth adder and the output end of the seventh adder are respectively connected to the two input ends of the second analog switching switch, the judgment signal that the unit load is lower than the set value and the condensate pump fault status signal are respectively connected to the two input ends of the OR gate logic module, the output end of the OR gate logic module is connected to the trigger signal input end of the second analog switching switch, and the output end of the second analog switching switch is connected to the access end of the deaerator water supply regulating valve control circuit.

[0020] As an optional implementation, each feedforward controller includes a dead zone module, a differential module, a proportional module and a saturation nonlinear module which are connected in series in sequence.

[0021] A second aspect of the present invention provides a coordinated automatic control method for a condensate system of a power plant based on a feedforward compensation technology.

[0022] A method for coordinated automatic control of a condensate system of a power plant based on feedforward compensation technology, using the coordinated control system of a condensate system of a power plant based on feedforward compensation described in the first aspect, comprises the following processes:

[0023] The first feedback controller is constructed using the measured value of condensate flow rate as a feedforward signal for hot well water level control;

[0024] The second feedforward controller is constructed using the measured value of condensate pressure as the decoupling control signal for deaerator water level control;

[0025] The third feedforward controller is constructed using the measured value of the deaerator water level as a decoupling control signal for condensate pressure control;

[0026] When the unit load is higher than the set value, the first analog switching switch selects to turn on the condensate flow control circuit, and the condensate pump inverter adjusts the condensate flow to control the deaerator water level; otherwise, the first analog switching switch selects to turn on the condensate pressure control circuit, and the condensate pump inverter controls the condensate pressure.

[0027] Furthermore, when the condensate pump inverter fails, the local control loop of the condensate pump inverter switches from the variable frequency control mode to the local industrial frequency control mode to maintain the condensate pump outlet constant pressure operation.

[0028] Furthermore, when the unit load is higher than the set value and the condensate pump inverter is in normal state, the measured value signal of the condensate pressure is output through the second feedforward controller and superimposed with the output signal of the first condensate flow controller as a control instruction for the condensate pump inverter to adjust the condensate flow to control the deaerator water level; at this time, the measured value signal of the deaerator water level is output through the third feedforward controller and superimposed with the output signal of the condensate pressure controller as a control instruction for the deaerator water supply regulating valve to control the condensate pressure.

[0029] Furthermore, under the premise of ensuring that the minimum condensate pressure and the safety of the condensate water level are met, the load point corresponding to the full opening of the deaerator water supply regulating valve is the load point corresponding to the step-by-step switching control of the deaerator water level and condensate pressure by the condensate pump inverter and the deaerator water supply regulating valve, and this load point is the set value of the load.

[0030] A third aspect of the present invention provides a coordinated automatic control method for a condensate system in a power plant based on feedforward compensation technology.

[0031] A method for coordinated automatic control of a condensate system of a power plant based on feedforward compensation technology, using the coordinated control system of a condensate system of a power plant based on feedforward compensation described in the first aspect, comprises the following processes:

[0032] The fourth feedforward controller is constructed using the measured value of the condensate pressure as a decoupling control signal for the deaerator water level control;

[0033] The fifth feedforward controller is constructed using the measured value of the deaerator water level as a decoupling control signal for condensate pressure control;

[0034] When receiving the signal that the unit load is lower than the set value or the condensate pump inverter is in fault state, the second analog switching switch selects to connect the condensate flow control circuit, and the deaerator water supply regulating valve adjusts the condensate flow to achieve deaerator water level control; otherwise, the second analog switching switch selects to connect the condensate pressure control circuit, and the deaerator water supply regulating valve controls the condensate pressure.

[0035] Furthermore, when the unit load is lower than the set value or the condensate pump inverter fails, the measured value signal of the condensate pressure is output through the fourth feedforward controller and superimposed with the output signal of the second condensate flow controller as the control instruction of the deaerator water supply regulating valve, so as to adjust the condensate flow to control the deaerator water level; when the unit is under low load and the condensate pump inverter is in normal state, the measured value signal of the deaerator water level is output through the fifth feedforward controller and superimposed with the output signal of the second condensate pressure controller as the control instruction of the condensate pump inverter to control the condensate pressure.

[0036] Furthermore, under the premise of ensuring that the minimum condensate pressure and the safety of the condensate water level are met, the load point corresponding to the full opening of the deaerator water supply regulating valve is the load point corresponding to the step-by-step switching control of the deaerator water level and condensate pressure by the condensate pump inverter and the deaerator water supply regulating valve, and this load point is the set value of the load.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The collaborative control system and method of the condensate system of a power plant based on feedforward compensation described in the present invention introduces the condensate flow signal as feedforward into the hot well water level control logic. During the control of the deaerator water level, when the condensate flow changes, the hot well water supply valve is actuated in advance, and there is no need to wait until the hot well water level changes to adjust the water supply valve. The disturbance effect of the condensate flow on the hot well water level is compensated in time, which reduces the response time of the hot well water level control and prevents the hot well water level from fluctuating too much.

[0039] 2. The collaborative control system and method of the condensate system of a power plant based on feedforward compensation described in the present invention introduces the condensate pressure signal as feedforward into the deaerator water level control logic. During the control of the condensate pressure, when the condensate pressure changes, the condensate pump speed or the opening of the deaerator water supply regulating valve is adjusted in advance without having to wait until the deaerator water level changes to make adjustments. The disturbance effect of the condensate pressure on the deaerator water level is compensated in time, thereby avoiding large dynamic deviations in the deaerator water level, reducing the lag and overshoot of the deaerator water level control, and improving the regulation quality of the control system.

[0040] 3. The collaborative control system and method of the condensate system of a power plant based on feedforward compensation described in the present invention introduces the deaerator water level signal as feedforward into the condensate pressure control logic. During the control of the deaerator water level, when the deaerator water level changes, the condensate pump speed or the opening of the deaerator water supply regulating valve is adjusted in advance without waiting until the condensate pressure changes to make adjustments. The disturbance effect of the deaerator water level on the condensate pressure is compensated in time, thereby avoiding large dynamic deviations in the condensate pressure, reducing the lag and overshoot of the condensate pressure control, and improving the regulation quality of the control system.

[0041] 4. The collaborative control system and method of the power plant condensate system based on feedforward compensation described in the present invention, through the decoupling control of the deaerator water level and the condensate pressure, the deaerator water level control and the condensate pressure control do not affect each other, thereby effectively eliminating the coupling effect of the deaerator water level and the condensate pressure.

[0042] 5. The feedforward compensation-based coordinated control system and method of the condensate system of a power plant described in the present invention solves the control problem of independent control of the three sub-loops and poor stability of the entire system in the traditional control scheme through the organic coordinated automatic control of the three control sub-loops of the hot well water level, the deaerator water level and the condensate pressure in the condensate system.

[0043] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0045] Figure 1 Schematic diagram of the structure of the coordinated control system of the condensate system of a power plant based on feedforward compensation provided in Example 1 of the present invention Figure 1 .

[0046] Figure 2 Schematic diagram of the structure of the coordinated control system of the condensate system of a power plant based on feedforward compensation provided in Example 1 of the present invention Figure 2 .

[0047] Among them, 1-the first hot well water level controller; 2-the first deaerator water level controller; 3-the first condensate pressure controller; 4-the first condensate flow controller; 5-the first feedforward controller; 6-the second feedforward controller; 7-the third feedforward controller; 8-the first adder; 9-the condensate pump; 10-the first adder; 11-the second adder; 12-the fourth adder; 13-the third adder; 14-the first analog quantity switching switch; 15-the second deaerator water level controller; 16-the second condensate pressure controller; 17-the third condensate flow controller; 18-the fourth feedforward controller; 19-the fifth feedforward controller; 20-the fifth adder; 21-the seventh adder; 22-the sixth adder; 23-the second analog quantity switching switch; 24-the OR gate logic module; 25-the deaerator water supply regulating valve. DETAILED DESCRIPTION

[0048] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0049] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0050] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0051] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0052] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0053] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0054] Embodiment 1:

[0055] Embodiment 1 of the present invention provides a condensate system collaborative control system for a power plant based on feedforward compensation. In the hot well water level control logic, a condensate flow signal is introduced to construct a feedforward controller. When the condensate flow changes during the control of the deaerator water level, the hot well water supply valve is actuated in advance, and there is no need to wait until the hot well water level changes to adjust the water supply valve. The disturbance effect of the condensate flow on the hot well water level is compensated in time, the response time of the hot well water level control is reduced, and the hot well water level fluctuation is prevented from being too large.

[0056] In the deaerator water level control logic, the condensate pressure signal is introduced to construct a feedforward controller. When the condensate pressure changes during the condensate pressure control process, the deaerator water level control loop adjusts the condensate flow rate in advance before the deaerator water level changes, eliminating the disturbance effect of the condensate pressure on the deaerator water level, and realizing the decoupling control of the deaerator water level when the condensate pressure is disturbed;

[0057] In the condensate pressure control logic, the deaerator water level signal is introduced to construct a feedforward controller. When the deaerator water level changes during the control process of the deaerator water level, the condensate pressure control loop adjusts the condensate pump speed or the opening of the deaerator water supply valve in advance before the condensate pressure changes, thereby eliminating the disturbance effect of the deaerator water level on the condensate pressure and realizing decoupling control of the condensate pressure when the deaerator water level is disturbed.

[0058] The present invention solves the control problem of independent control of the three sub-loops and poor stability of the entire system in the traditional control scheme through the organic coordinated automatic control of the three control sub-loops of the hot well water level, deaerator water level and condensate pressure in the condensate system, so as to achieve rapid balance of the hot well water level, deaerator water level and condensate pressure control loops when the unit load changes rapidly and frequently, thereby enhancing the robustness of the entire condensate control system and meeting the unit's full operating condition operation control needs.

[0059] Specifically, Figure 1 ,include:

[0060] The first condenser hot well water level controller 1 is used to receive the hot well water level set value and the hot well water level measured value, the input end of the first feedforward controller 5 is used to receive the condensate flow measured value, the output end of the first feedforward controller 5 and the output end of the first hot well water level controller 1 are respectively connected to the input end of the first adder 10, and the output end of the first adder 10 is connected to the control loop input end of the condenser hot well water supply regulating valve 8;

[0061] The input end of the first deaerator water level controller 2 is used to receive the deaerator water level setting value and the deaerator water level actual value, and the input end of the first condensate pressure controller 3 is used to receive the condensate pressure setting value and the condensate pressure actual value;

[0062] The input end of the second adder 11 is used to receive the output signal of the first deaerator water level controller 2 and the measured value of the feed water flow rate, the output end of the second adder 11 is connected to the positive input end of the first condensate flow controller 4, and the negative input end of the first condensate flow controller 4 is used to receive the condensate flow signal;

[0063] The input end of the second feedforward controller 6 is used to receive the measured value of the condensate pressure, and the output end of the second feedforward controller 6 and the output end of the first condensate flow controller 4 are respectively connected to two input ends of the third adder 13;

[0064] The input end of the third feedforward controller 7 is used to receive the measured value of the deaerator water level, and the output end of the third feedforward controller 7 and the output end of the first condensate pressure controller 3 are respectively connected to the two input ends of the fourth adder 12;

[0065] The output end of the third adder 13 and the output end of the fourth adder 12 are respectively connected to the two input ends of the first analog switching switch 14, the judgment signal that the unit load is higher than the set value is connected to the trigger signal input end of the first analog switching switch 14, and the output end of the first analog switching switch 14 is connected to the inverter control circuit access end of the condensate pump 9.

[0066] like Figure 2 As shown, the input end of the second deaerator water level controller 15 is used to receive the deaerator water level setting value and the deaerator water level actual value, and the input end of the second condensate pressure controller 16 is used to receive the condensate pressure setting value and the condensate pressure actual value;

[0067] The input end of the fifth adder 20 is used to receive the output signal of the second deaerator water level controller and the measured value of the feed water flow rate, the output end of the fifth adder 20 is connected to the positive input end of the second condensate flow controller 17, and the negative input end of the second condensate flow controller 17 is used to receive the condensate flow signal;

[0068] The input end of the fourth feedforward controller 18 is used to receive the measured value of the condensate pressure, and the output end of the fourth feedforward controller 18 and the output end of the second condensate flow controller 16 are respectively connected to the two input ends of the sixth adder 22;

[0069] The input end of the fifth feedforward controller 19 is used to receive the measured value of the deaerator water level, and the output end of the fifth feedforward controller 19 and the output end of the second condensate pressure controller 16 are respectively connected to the two input ends of the seventh adder 21;

[0070] The output end of the sixth adder 22 and the output end of the seventh adder 21 are respectively connected to the two input ends of the second analog quantity switching switch 23, the judgment signal that the unit load is lower than the set value and the condensate pump fault status signal are respectively connected to the two input ends of the OR gate logic module 24, the output end of the OR gate logic module 24 is connected to the trigger signal input end of the second analog quantity switching switch 23, and the output end of the second analog quantity switching switch 23 is connected to the control loop access end of the deaerator water supply regulating valve 25.

[0071] Each feedforward controller described in this embodiment includes a dead zone module, a differential module, a proportional module and a saturation nonlinear module connected in sequence, wherein:

[0072] The dead zone module is used to limit the interference to the control system caused by slight changes in the feedforward source signal;

[0073] The differential module and the proportional module enable the control loop to act quickly with the change of the feedforward source signal, eliminating the influence of the feedforward source signal change on the system disturbance;

[0074] The function of the saturation nonlinear module is to limit the influence of excessive differential action on the control system.

[0075] Embodiment 2:

[0076] Embodiment 2 of the present invention provides a method for cooperatively controlling a condensate system of a power plant based on feedforward compensation, using the cooperative automatic control system of a condensate system of a power plant based on the feedforward compensation technology described in Embodiment 1, including the following process:

[0077] A feedforward controller is constructed using the condensate flow rate as a feedforward signal for hot well water level control;

[0078] A feedforward controller is constructed using condensate pressure as a decoupling control signal for deaerator water level control.

[0079] A feedforward controller is constructed using the deaerator water level as a decoupled control signal for condensate pressure control.

[0080] S1: When the unit is under high load and the condensate pump inverter is in normal state, the measured value signal of the condensate pressure is output through the feedforward controller and superimposed with the output signal of the condensate flow controller as the control instruction of the condensate pump inverter to adjust the condensate flow to control the deaerator water level; at this time, the measured value signal of the deaerator water level is output through the feedforward controller and superimposed with the output signal of the condensate pressure controller as the control instruction of the deaerator water supply regulating valve to control the condensate pressure.

[0081] More specifically, when the unit load is higher than the set value (such as ≥45% of the rated load), the first analog switching switch selects to turn on the condensate flow control circuit, and the condensate pump inverter adjusts the condensate flow to achieve deaerator water level control; otherwise, the first analog switching switch selects to turn on the condensate pressure control circuit, and the condensate pump inverter controls the condensate pressure; when the condensate pump inverter fails, the local control circuit of the condensate pump inverter switches from the variable frequency control mode to the local industrial frequency control mode to maintain the condensate pump outlet constant pressure operation.

[0082] S2: When the unit is under low load (such as <45% rated load) or the inverter of the condensate pump fails, the measured condensate pressure signal is output through the feedforward controller and superimposed with the output signal of the condensate flow controller as the control command of the deaerator water supply regulating valve to adjust the condensate flow to control the deaerator water level; when the inverter of the condensate pump fails, the local control loop of the inverter of the condensate pump switches from the variable frequency control mode to the local industrial frequency control mode to maintain the constant pressure operation of the condensate pump outlet.

[0083] When the unit is under low load (such as <45% of rated load) and the condensate pump inverter is in normal condition, the deaerator water level measured value signal is output through the feedforward controller and superimposed with the output signal of the condensate pressure controller as the condensate pump inverter control instruction to control the condensate pressure.

[0084] Specifically, when receiving a signal that the unit load is lower than the set value or the condensate pump inverter is in fault state, the second analog switching switch selects to connect the condensate flow control loop, and the deaerator water supply regulating valve adjusts the condensate flow to achieve deaerator water level control; otherwise, the second analog switching switch selects to connect the condensate pressure control loop, and the deaerator water supply regulating valve controls the condensate pressure.

[0085] When the condensate pump inverter is in normal state, the condensate pump inverter and the deaerator water supply regulating valve can realize the split-range control of the deaerator water level and condensate pressure through the unit load point. The unit load point can be obtained through field tests. Under the premise of ensuring that the minimum condensate pressure and the condensate water level are met, the load point corresponding to the full opening of the deaerator water supply regulating valve is the load point corresponding to the split-range switching control of the deaerator water level and condensate pressure by the condensate pump inverter and the deaerator water supply regulating valve in this embodiment. When the load point is above, the deaerator water level control is realized by controlling the condensate pump speed to adjust the condensate flow rate; when the load point is below, the deaerator water level control is realized by controlling the opening of the condensate deaerator water supply regulating valve to adjust the condensate flow rate.

[0086] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0087] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0088] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0089] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0090] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coordinated control system for a condensate system in a power plant based on feedforward compensation, characterized in that: include: The first condenser hot well water level controller is used to receive the hot well water level set value and the hot well water level measured value, the input end of the first feedforward controller is used to receive the condensate flow measured value, the output end of the first feedforward controller and the output end of the first hot well water level controller are respectively connected to the input end of the first adder, and the output end of the first adder is connected to the input end of the condenser hot well water replenishment regulating valve control circuit; The input end of the first deaerator water level controller is used to receive the deaerator water level setting value and the deaerator water level actual value, and the input end of the first condensate pressure controller is used to receive the condensate pressure setting value and the condensate pressure actual value; The input end of the second adder is used to receive the output signal of the first deaerator water level controller and the measured value of the feed water flow rate, the output end of the second adder is connected to the positive input end of the first condensate flow controller, and the negative input end of the first condensate flow controller is used to receive the condensate flow signal; The input end of the second feedforward controller is used to receive the measured value of the condensate pressure, and the output end of the second feedforward controller and the output end of the first condensate flow controller are respectively connected to two input ends of the third adder; The input end of the third feedforward controller is used to receive the measured value of the deaerator water level, and the output end of the third feedforward controller and the output end of the first condensate pressure controller are respectively connected to two input ends of the fourth adder; The output end of the third adder and the output end of the fourth adder are respectively connected to the two input ends of the first analog switching switch, the judgment signal that the unit load is higher than the set value is connected to the trigger signal input end of the first analog switching switch, and the output end of the first analog switching switch is connected to the access end of the condensate pump inverter control circuit.

2. The feedforward compensation-based coordinated control system for a condensate system in a power plant according to claim 1, characterized in that: The input end of the second deaerator water level controller is used to receive the deaerator water level setting value and the deaerator water level actual value, and the input end of the second condensate pressure controller is used to receive the condensate pressure setting value and the condensate pressure actual value; The input end of the fifth adder is used to receive the output signal of the second deaerator water level controller and the measured value of the feed water flow rate, the output end of the fifth adder is connected to the positive input end of the second condensate flow controller, and the negative input end of the second condensate flow controller is used to receive the condensate flow signal; The input end of the fourth feedforward controller is used to receive the measured value of the condensate pressure, and the output end of the fourth feedforward controller and the output end of the second condensate flow controller are respectively connected to the two input ends of the sixth adder; The input end of the fifth feedforward controller is used to receive the measured value of the deaerator water level, and the output end of the fifth feedforward controller and the output end of the second condensate pressure controller are respectively connected to the two input ends of the seventh adder; The output end of the sixth adder and the output end of the seventh adder are respectively connected to the two input ends of the second analog switching switch, the judgment signal that the unit load is lower than the set value and the condensate pump fault status signal are respectively connected to the two input ends of the OR gate logic module, the output end of the OR gate logic module is connected to the trigger signal input end of the second analog switching switch, and the output end of the second analog switching switch is connected to the access end of the deaerator water supply regulating valve control circuit.

3. The coordinated control system of the condensate system of a power plant based on feedforward compensation according to claim 2, characterized in that: Each feedforward controller includes a dead zone module, a differential module, a proportional module and a saturation nonlinear module which are connected in series in sequence.

4. A coordinated automatic control method for a condensate system in a power plant based on feedforward compensation technology, characterized in that: The coordinated control system of the condensate system of a power plant based on feedforward compensation as claimed in claim 1 or 3 comprises the following processes: The first feedback controller is constructed using the measured value of condensate flow rate as a feedforward signal for hot well water level control; The second feedforward controller is constructed using the measured value of condensate pressure as the decoupling control signal for deaerator water level control; The third feedforward controller is constructed using the measured value of the deaerator water level as a decoupling control signal for condensate pressure control; When the unit load is higher than the set value, the first analog switching switch selects to turn on the condensate flow control circuit, and the condensate pump inverter adjusts the condensate flow to control the deaerator water level; otherwise, the first analog switching switch selects to turn on the condensate pressure control circuit, and the condensate pump inverter controls the condensate pressure.

5. The method for coordinated automatic control of a condensate system in a power plant based on feedforward compensation technology according to claim 4, characterized in that: When the condensate pump inverter fails, the local control loop of the condensate pump inverter switches from variable frequency control mode to local industrial frequency control mode to maintain the condensate pump outlet constant pressure operation.

6. The method for coordinated automatic control of a condensate system in a power plant based on feedforward compensation technology according to claim 4, characterized in that: When the unit load is higher than the set value and the condensate pump inverter is in normal state, the measured value signal of the condensate pressure is output through the second feedforward controller and superimposed with the output signal of the first condensate flow controller as the condensate pump inverter control instruction to adjust the condensate flow to control the deaerator water level; at this time, the measured value signal of the deaerator water level is output through the third feedforward controller and superimposed with the output signal of the condensate pressure controller as the deaerator water supply regulating valve control instruction to control the condensate pressure.

7. The method for coordinated automatic control of a condensate system in a power plant based on feedforward compensation technology according to claim 4, characterized in that: On the premise of ensuring that the minimum condensate pressure and condensate water level are safe, the load point corresponding to the full opening of the deaerator water supply regulating valve is the load point corresponding to the step-by-step switching control of the deaerator water level and condensate pressure by the condensate pump inverter and the deaerator water supply regulating valve. This load point is the set value of the load.

8. A coordinated automatic control method for a condensate system in a power plant based on feedforward compensation technology, characterized in that: The coordinated control system of the condensate system of a power plant based on feedforward compensation as claimed in claim 2 or 3 comprises the following processes: The fourth feedforward controller is constructed using the measured value of the condensate pressure as a decoupling control signal for the deaerator water level control; The fifth feedforward controller is constructed using the measured value of the deaerator water level as a decoupling control signal for condensate pressure control; When receiving the signal that the unit load is lower than the set value or the condensate pump inverter is in fault state, the second analog switching switch selects to connect the condensate flow control circuit, and the deaerator water supply regulating valve adjusts the condensate flow to achieve deaerator water level control; otherwise, the second analog switching switch selects to connect the condensate pressure control circuit, and the deaerator water supply regulating valve controls the condensate pressure.

9. The method for coordinated automatic control of a condensate system in a power plant based on feedforward compensation technology according to claim 8, characterized in that: When the unit load is lower than the set value or the condensate pump inverter fails, the measured value signal of the condensate pressure is output through the fourth feedforward controller and superimposed with the output signal of the second condensate flow controller as the control instruction of the deaerator water supply regulating valve to adjust the condensate flow to control the deaerator water level; when the unit is under low load and the condensate pump inverter is in normal state, the measured value signal of the deaerator water level is output through the fifth feedforward controller and superimposed with the output signal of the second condensate pressure controller as the control instruction of the condensate pump inverter to control the condensate pressure.

10. The method for coordinated automatic control of a condensate system in a power plant based on feedforward compensation technology according to claim 8, characterized in that: On the premise of ensuring that the minimum condensate pressure and condensate water level are safe, the load point corresponding to the full opening of the deaerator water supply regulating valve is the load point corresponding to the step-by-step switching control of the deaerator water level and condensate pressure by the condensate pump inverter and the deaerator water supply regulating valve. This load point is the set value of the load.

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