A DCS simulation control system and method for a thermal power plant containing a physical condenser object

Abstract

The present invention discloses a DCS simulation control system and method for a thermal power plant including a physical condenser object. The DCS simulation control system comprises: a power plant virtual simulator for simulating the power plant's operating conditions and outputting steam condensation and condenser condensation; a host computer for displaying control effects; a DCS control system for outputting condenser feed water volume; the physical condenser object comprises an inlet control valve, an outlet control valve, a water tank, and a liquid level sensor; the liquid level sensor is used to obtain water tank level information; the inlet control valve control signal is obtained by the DCS control system based on the steam condensation volume and the condenser feed water volume; and the outlet control valve control signal is obtained by the DCS control system based on the condenser condensation volume. This invention can more realistically simulate the condenser level control process in a power plant and assist researchers and trainers in exploring control and management methods for power plants.

Description

Technical Field

[0001] The present invention belongs to the technical field of automated simulation and scientific research teaching aids, relates to the field of thermal power plant simulation control, and particularly relates to a thermal power plant DCS (distributed control system) simulation control system and method containing a condenser physical object. Background Art

[0002] The operating environment of thermal power plants is unique, and researchers and trainers cannot conduct in-depth research and training in power plants for a long time. In view of the above problems, the importance of power plant control simulation platforms is highlighted.

[0003] Currently, the existing thermal power plant simulation methods still have the following defects:

[0004] (1) Most existing thermal power plant simulations are fully virtual, and there are few thermal power systems that use semi-physical simulations.

[0005] (2) Most existing hardware-in-the-loop simulation systems for thermal power plants are DCS control systems, and peripheral control equipment is rarely installed. Even if peripheral control equipment is installed, the control method of the peripheral equipment is not flexible enough.

[0006] (3) The control method of the existing semi-physical control system of thermal power plants is relatively simple and the control system cannot be switched freely.

[0007] In summary, in order to assist researchers and train personnel in exploring the control and management methods of power plants, improve research on power plants, and promote the development of power plant management and research, a new semi-physical simulation platform based on mainstream DCS is urgently needed. Summary of the Invention

[0008] The present invention aims to provide a DCS simulation control system and method for a thermal power plant that includes a physical condenser object, thereby resolving one or more of the aforementioned technical problems. The DCS simulation control system provided by the present invention incorporates a physical condenser object, enabling a more realistic simulation of the condenser liquid level control process. This system can assist researchers and trainees in exploring control and management methods for power plants, enhance research on power plants, and promote the development of power plant management and research.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The present invention provides a DCS simulation control system for a thermal power plant containing a condenser physical object, comprising: a power plant virtual simulation machine, a host computer, a switch, a DCS control system, and a condenser physical object; the switch is used to realize data interaction between the power plant virtual simulation machine, the host computer, and the DCS control system;

[0011] The power plant virtual simulator is used to simulate the operating conditions of a thermal power plant and output the steam condensation amount and the condenser condensation amount;

[0012] The host computer is used to display the control effect of the thermal power plant DCS simulation control system;

[0013] The DCS control system is used to output the condenser water replenishment amount according to the liquid level information transmitted by the condenser physical object and the preset liquid level threshold;

[0014] The physical object of the condenser includes an inlet control valve, an outlet control valve, a water tank and a liquid level sensor; the liquid level sensor is used to obtain liquid level information of the water tank; wherein, the control signal of the inlet control valve is obtained by the DCS control system based on the steam condensation amount and the condenser water supply amount, and the control signal of the outlet control valve is obtained by the DCS control system based on the condensation amount of the condenser.

[0015] A further improvement of the present invention is that the power plant virtual simulator is used to simulate the operating conditions of a thermal power plant, specifically:

[0016] The power plant virtual simulator is used to simulate the operating conditions of a thermal power plant based on the condenser feed water volume delivered by the DCS control system.

[0017] A further improvement of the present invention is that it also includes:

[0018] The remote control center is used to control the thermal power plant model of the power plant virtual simulator based on the remote network and the switch.

[0019] A further improvement of the present invention is that the host computer is used to display the control effect of the thermal power plant DCS simulation control system, including:

[0020] The power plant virtual simulator and the host computer are connected by a relational database. The power plant operation data in the power plant virtual simulator is transmitted to the host computer through JXServer. The host computer displays the power plant operation status on a configured interface that has been built.

[0021] A further improvement of the present invention is that the host computer is used to display the control effect of the thermal power plant DCS simulation control system, including:

[0022] The DCS control system obtains the liquid level information of the physical object of the condenser, and feeds the liquid level information back to the upper computer configuration interface through the DCS control system.

[0023] A further improvement of the present invention is that the mathematical model of the condenser in the power plant virtual simulator is:

[0024] (1) Steam area:

[0025] The mass conservation equation is Among them, W s is the steam volume on the shell side of the condenser, W nd is the steam turbine exhaust volume, W as is the amount of steam condensation, ρ s is the steam density; V is the volume of the steam and gas space of the condenser;

[0026] The average enthalpy is Among them, H s is the average enthalpy of steam, H ed is the exhaust enthalpy of the steam turbine;

[0027] Q s =W ed (H ed -C w T s )-(W ed -W as )(H s -C w T s );

[0028]

[0029]

[0030] P s =f(T s );

[0031] H s =f(T s );

[0032] ρ s =f(T s );

[0033] Where, T s is the average temperature of steam in the condenser, P s is the condenser pressure, Q s is the heat released by steam condensation, C w is the specific heat capacity of cooling water, T1 and T2 are the inlet and outlet temperatures of cooling water, α n is the convection heat release coefficient, S1 is the heat exchange area;

[0034] (2) Hot well water area:

[0035]

[0036]

[0037]

[0038] Where W w is the water storage capacity of the hot well, W l is the condenser water output, L is the hot well water level, A is the hot well cross-sectional area, H as is the saturated water enthalpy at condenser pressure, H w is the enthalpy of hot well water;

[0039] (3) Cooling water pipe model:

[0040]

[0041] Where M cw is the water storage capacity of the cooling water pipe, D w is the cooling water flow rate.

[0042] The present invention provides a DCS simulation control method for a thermal power plant including a condenser physical object, based on the above-mentioned DCS simulation control system of the thermal power plant of the present invention, comprising the following steps:

[0043] Simulating the operating conditions of a thermal power plant through the power plant virtual simulator to output the steam condensation amount and the condenser condensation amount;

[0044] Displaying the control effect of the DCS simulation control system of the thermal power plant through the host computer;

[0045] The DCS control system outputs the condenser water replenishment amount according to the liquid level information transmitted by the condenser physical object and the preset liquid level threshold;

[0046] outputting liquid level information through the condenser physical object;

[0047] The water inlet control valve is simulated and controlled by a control signal obtained by the DCS control system based on the steam condensation amount and the condenser water supply amount; the water outlet control valve is simulated and controlled by a control signal obtained by the DCS control system based on the condensation amount of the condenser;

[0048] Data interaction between the power plant virtual simulator, host computer and DCS control system is achieved through switches.

[0049] A further improvement of the present invention is that the step of simulating the operating conditions of a thermal power plant by using the power plant virtual simulator comprises:

[0050] The power plant virtual simulator simulates the operating conditions of the thermal power plant based on the condenser make-up water volume delivered by the DCS control system.

[0051] A further improvement of the present invention is that the step of displaying the control effect of the thermal power plant DCS simulation control system by the host computer includes:

[0052] The power plant virtual simulator and the host computer are connected by a relational database. The power plant operation data in the power plant virtual simulator is transmitted to the host computer through JXServer. The host computer displays the power plant operation status on a pre-built configuration interface.

[0053] The DCS control system obtains the liquid level information of the physical object of the condenser, and feeds the liquid level information back to the upper computer configuration interface through the DCS control system.

[0054] A further improvement of the present invention is that the mathematical model of the condenser in the power plant virtual simulator is:

[0055] (1) Steam area:

[0056] The mass conservation equation is Among them, W s is the steam volume on the shell side of the condenser, W nd is the steam turbine exhaust volume, W as is the amount of steam condensation, ρ s is the steam density; V is the volume of the steam and gas space of the condenser;

[0057] The average enthalpy is Among them, H s is the average enthalpy of steam, H ed is the exhaust enthalpy of the steam turbine;

[0058] Q s =W ed (H ed -C w T s )-(W ed -W as )(H s -C w T s );

[0059]

[0060]

[0061] P s =f(T s );

[0062] H s =f(T s );

[0063] ρ s =f(T s );

[0064] Where, T s is the average temperature of steam in the condenser, P sis the condenser pressure, Q s is the heat released by steam condensation, C w is the specific heat capacity of cooling water, T1 and T2 are the inlet and outlet temperatures of cooling water, α n is the convection heat release coefficient, S1 is the heat exchange area;

[0065] (2) Hot well water area:

[0066]

[0067]

[0068]

[0069] Where W w is the water storage capacity of the hot well, W l is the condenser water output, L is the hot well water level, A is the hot well cross-sectional area, H as is the saturated water enthalpy at condenser pressure, H w is the enthalpy of hot well water;

[0070] (3) Cooling water pipe model:

[0071]

[0072] Where M cw is the water storage capacity of the cooling water pipe, D w is the cooling water flow rate.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] The DCS simulation control system for a thermal power plant provided by the present invention includes a physical condenser object. Based on the liquid level feedback from the multi-capacity object, the DCS controller automatically adjusts the valve openings of the inlet and outlet pumps to control the water flow rate, bringing the liquid level of the physical condenser object into dynamic equilibrium, thereby more realistically simulating the condenser liquid level control process in the power plant. Specifically, in a laboratory setting, high temperature and high pressure environments cannot be used to simulate actual power plant operations. To more realistically simulate actual power plant operations, the present invention employs semi-physical simulation to approximate a real power plant as closely as possible. Furthermore, unlike existing thermal power plant semi-physical simulation systems, which are mostly based on PLC control systems, the technical solution provided by the present invention not only utilizes the most advanced DCS control system but also adds a physical condenser liquid level control object. Based on a hardware-in-the-loop simulation model, the DCS control system, switches, a host computer, and peripheral condenser liquid level control equipment are incorporated into the thermal power plant simulation system, improving the level of semi-physical simulation and better reflecting the various complex industrial conditions involved in power plant operation and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art; obviously, the drawings described below are some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0076] Figure 1 Schematic diagram of a hardware-in-the-loop simulation platform based on a DCS control system provided by an embodiment of the present invention;

[0077] Figure 2 1 is a schematic diagram of the principle of a condenser object in an embodiment of the present invention;

[0078] Figure 3 Schematic diagram of the water inlet pump tracking the sum of the exhaust steam condensation amount and the make-up water amount of the steam turbine in an embodiment of the present invention;

[0079] Figure 4 Schematic diagram of the outlet pump tracking the condensate amount of the condenser in an embodiment of the present invention;

[0080] Figure 5 Schematic diagram of a condenser liquid level DCS controller according to an embodiment of the present invention;

[0081] Figure 6 This is a schematic diagram of the actual control effect of the configuration interface in an embodiment of the present invention;

[0082] In the figure, 1. Power plant virtual simulator; 2. Host computer; 3. Switch; 5. DCS control system; 6. Condenser physical object; 7. Steam turbine. DETAILED DESCRIPTION

[0083] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0084] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0085] The present invention is described in further detail below with reference to the accompanying drawings:

[0086] See also Figure 1 The embodiment of the present invention provides a DCS simulation control system for a thermal power plant including a condenser physical object, comprising: a power plant virtual simulation machine 1, a host computer 2, a switch 3, a DCS control system 5, and a condenser physical object 6;

[0087] The power plant virtual simulator 1 is used to simulate the operating conditions of the coal-fired power plant according to the input control signal, and output the steam condensation amount and the condenser condensation amount;

[0088] The host computer 2 is equipped with a preset DCS control configuration software for displaying the control effect of the thermal power plant DCS simulation control system;

[0089] The switch 3 is used to realize data interaction between the power plant virtual simulation machine 1, the host computer 2, the DCS control system 5, etc.

[0090] The DCS control system 5 is used to input the liquid level height of the multi-capacity object, and output a control signal for inputting the power plant virtual simulator 1 and a control signal for inputting the condenser physical object 6 according to the liquid level height;

[0091] The condenser physical object 6 includes components such as a water inlet control valve, a water outlet control valve, a water tank, and a water tank bottom sensor. It is the peripheral control equipment of the system and is used to simulate the condenser liquid level control effect.

[0092] In the DCS simulation control system of a thermal power plant provided by an embodiment of the present invention, liquid level information detected by a liquid level sensor at the bottom of the actual condenser is transmitted to the DCS control system. The DCS system controls the condenser feed water quantity based on the liquid level deviation between the set liquid level value and the actual value, thereby maintaining the liquid level near the set value. Specifically, an inlet pump is used to simulate the steam condensation amount of the low-pressure cylinder of turbine 7 and the condenser feed water quantity, and a discharge pump is used to simulate the condensation amount of the condenser. The feed water pump and the traditional inlet pump are innovatively combined into one, and the feed water pump control quantity is applied to the inlet pump control quantity, thereby reducing the number of water pumps and achieving the predetermined control target.

[0093] As a specific example of the embodiment of the present invention, the power plant virtual simulator 1 is pre-built with an overall mechanism model of the thermal power plant, including three major systems: combustion and air and smoke system, boiler system, steam turbine 7 and its bypass system, so as to realize a full range of simulation of the entire thermal power plant.

[0094] See also Figures 2 to 5 In a specific exemplary embodiment of the present invention, the DCS control system 5 includes a main controller, a data forwarding card, I / O cards (XP314-6-channel voltage signal input card, XP243-main control card, XP211-cage, XP233-data forwarding card, XP372-8-channel current signal output card, etc.), a JX Server, a power supply, and other components, which serve as the control core of the entire semi-physical system. Among them, P11_129 is a water outflow tracking controller, P11_130 is a four-byte to two-byte byte converter, P11_123 is a water inflow tracking controller, and P11_136 is an adder.

[0095] In a specific exemplary embodiment of the present invention, the host computer 2 is a configuration interface built based on the DCS control system 5, which is used to monitor the status of the thermal power plant in the simulation machine in real time; the switch 3 is used for communication between the simulation machine, the host computer 2 and the DCS control system 5.

[0096] Preferably, in the embodiment of the present invention, a remote control center may be provided to connect to a remote network for receiving a preset advanced control algorithm to achieve higher precision control of the thermal power plant.

[0097] In an exemplary embodiment of the present invention, the simulation machine and the host computer 2 are connected by a JBDC (data-oriented relational) database; the power plant operation data in the simulation machine is transmitted to the host computer 2 in real time through the JX Server, and the host computer 2 displays the current power plant operation status on the already built configuration interface.

[0098] Preferably, in an embodiment of the present invention, the semi-physical simulation platform provides two sets of control algorithms for some control loops of the power plant, one of which is provided by the simulation machine and the other is built on the DCS control system 5, and can freely switch between the two control modes; wherein, the DCS control system 5 reads the parameters of the liquid level sensor at the bottom of the condenser physical object 6 through the XP314 board, and feeds back the liquid level information to the configuration interface of the host computer 2 through the DCS system, and the DCS control system 5 provides a control variable to act on the water inlet pump; the valve opening of the water inlet pump is determined by two parts: one part is the condensation amount of the turbine exhaust steam, and the other part is the liquid level control amount provided by the DCS controller, and the sum of the two jointly determines the valve opening; the valve opening of the water outlet pump is completely determined by the condensation amount of the condenser. When the water inlet and water outlet reach a dynamic balance, the liquid level of the condenser is maintained near the set value.

[0099] Specifically, the main task of a power plant's condenser is to condense the exhaust steam from steam turbine 7 into water and establish and maintain a certain vacuum at the exhaust port. Its reliability directly impacts the safe and economical operation of the entire generator set. The condenser can be considered a surface heat exchanger. Cooling water flows through the tubes, removing the temperature of the final exhaust steam from steam turbine 7. After condensation, the exhaust steam from steam turbine 7 continues to circulate in the boiler for heating. A certain vacuum is maintained within the condenser to maximize the power output of steam turbine 7 and facilitate the condensation of the exhaust steam. Due to the limitations of typical laboratories, which cannot provide a cooling water system and a negative pressure environment, the system has been simplified to retain only the physical control portion of the hot well water level. Both the cooling water system and the negative pressure environment are simulated using a simulator.

[0100] In the embodiment of the present invention, the mathematical model of the condenser in the simulator is as follows:

[0101] 1. Steam area:

[0102] The mass conservation equation is

[0103] Among them, W s is the steam volume on the shell side of the condenser, W nd is the steam turbine exhaust volume, W as is the amount of steam condensation, ρ s is the steam density; V is the volume of the steam and gas space in the condenser.

[0104] The average enthalpy is

[0105] Among them, H s is the average enthalpy of steam, H ed is the exhaust enthalpy of the steam turbine.

[0106] Q s =W ed (Hed -C w T s )-(W ed -W as )(H s -C w T s ) (3)

[0107]

[0108]

[0109] P s =f(T s ) (6)

[0110] H s =f(T s ) (7)

[0111] ρ s =f(T s ) (8)

[0112] Among them, T s is the average temperature of steam in the condenser, P s is the condenser pressure, Q s is the heat released by steam condensation, C w is the specific heat capacity of cooling water, T1 and T2 are the inlet and outlet temperatures of cooling water, α n is the convection heat release coefficient, and S1 is the heat exchange area.

[0113] 2. Hot well water area:

[0114]

[0115]

[0116]

[0117] Among them, W w is the water storage capacity of the hot well, W l is the condenser water output, L is the hot well water level, A is the hot well cross-sectional area, H as is the saturated water enthalpy at condenser pressure, H w is the enthalpy of hot well water.

[0118] 3. Cooling water pipe model:

[0119]

[0120] Among them, M cw is the water storage capacity of the cooling water pipe, D w is the cooling water flow rate.

[0121] In an embodiment of the present invention, the control method used in the DCS system thermal power plant semi-physical simulation platform described above is adopted, including the following steps:

[0122] 1) The outlet water pump tracks the condensate volume of the condenser as outlet water. Since the data CO_WasCNCC transmitted from the simulation model is four bytes, while the input of the P11_129 controller is only two bytes, P11_130 is required to convert the data from four bytes to two bytes CO_WasCNCCsf. The P11_129 controller is a tracking controller. Its input TV is the converted condensate flow rate, and its output is the tracking amount of the condensate flow rate. The output signal is sent to the A001000100 terminal of the current signal output card XP372 to control the opening of the outlet water pump valve.

[0123] 2) The water inlet pump tracks the turbine condensate and condenser feed water as the inlet water. P11_86 is the inlet water tracking controller. Its input quantity TV is the converted sum of the turbine condensate and condenser feed water, Co_WasCNCsf. The output signal is sent to the A001000101 terminal of the current signal output card XP372 to control the opening of the water inlet pump valve.

[0124] 3) The DCS controller detects the liquid level of the multi-tank through a liquid level sensor and transmits it to the switch via XP314 in the form of a 0-5V voltage, which is then sent to the simulation program. After the corresponding voltage-to-liquid level conversion, it is sent to the PV terminal as the actual value. The set value of the liquid level is based on the height of the condenser of a 600MW unit, with SV set to 6 meters. Based on the deviation between the actual liquid level detected and the set level, the controller uses a PID algorithm to determine the control variable to change the opening of the water inlet valve, and the output MV is a control variable of 0-100.

[0125] 4) P11_136 is an adder. Its result is the sum of the turbine steam condensate CO_WasCNCsf and the condenser liquid level control value YWDY, CO_WasCNCsf_add. The sum of the two is used as the tracking value of the water inlet pump TV. The tracking result MV acts on the water inlet pump through the analog output card XP372 to control the opening of the water inlet pump valve. The condenser condensate flow rate is used as the control value of the water outlet valve. When the water inlet and water outlet reach dynamic balance, the condenser liquid level will be maintained at the set value. Appendix: Figure 6 The middle curve MV is the controlled variable, the curve SV is the actual liquid level, and the curve PV is the set value. The deviation between SV and PV meets the accuracy requirements and the control effect is good.

[0126] The working principle of the technical solution provided by the embodiment of the present invention is explained, including:

[0127] 1) Working principle of system software:

[0128] The simulator simulates the thermal power plant system object and is equipped with the Matlab virtual simulation program for the power plant system. The control interface transmits ultra-real-time simulation data to the host computer configuration interface to display the current simulation status. The DCS configuration software is built on the host computer, including an overview diagram and detailed diagram of the entire thermal power plant system, as well as a monitoring curve software interface and a controller switching interface, etc., displaying more than 500 status quantities provided by the simulator, DCS controller, and actual condenser.

[0129] 2) System hardware working principle:

[0130] Industrial Ethernet switches, based on the OPC communication protocol, enable interaction between the DCS system and the host computer, as well as between the simulator and the host computer. The data transmitted includes: the real-time status of the simulator, the control quantity calculated by the DCS controller, and the status of peripheral devices read by the DCS system.

[0131] The DCS system exchanges data with the server in real time through OPC communication, transmits the water replenishment control quantity control signal to the simulator, and controls the thermal power plant model in real time. It also collects data from external hardware devices through the DCS system's hardware input and output boards, and the DCS controller calculates the required control quantity, thereby controlling the external devices.

[0132] The physical objects of the condenser include the water inlet pump, water outlet pump, water storage tank, condenser liquid level tank and related control interfaces. A liquid level sensor is installed at the bottom of the condenser liquid level tank, which transmits the liquid level status to the DCS liquid level controller in real time through the voltage signal input card XP314.

[0133] The embodiment of the present invention provides a semi-physical simulation platform based on a DCS system, which includes: a power plant virtual simulator, a host computer, a switch, a DCS system and a condenser physical object; wherein the power plant simulator is equipped with an entire model of the power plant to simulate the overall operation process of the power plant; the host computer mainly includes an OPC server, a power plant operation history database and DCS configuration monitoring software; the industrial Ethernet switch serves as the data transmission hub of the entire semi-physical system, realizing data interaction based on the OPC communication protocol; the DCS system, as the control module of the entire power plant system, not only undertakes the operation of relevant control loops of the power plant, but also is responsible for collecting external data and providing data interfaces for external hardware devices through the input and output boards of the DCS system; the condenser physical object transmits the liquid level information read by the liquid level sensor in the container to the controller through the core hardware XP314 of the DCS system, thereby providing a control quantity to control the opening of the water inlet valve, and is also equipped with a water outlet pump to simulate the condensation amount of the condenser.

[0134] In the technical solution provided by the present invention, the semi-physical control system includes: a DCS system control cabinet, a communication station switch, a host computer and the peripheral control equipment built; the simulation part includes: a complete coal-fired power plant simulation system and corresponding controllers, etc. In a laboratory environment, it is not possible to use a high temperature and high pressure environment to simulate the actual operation of a power plant. In order to simulate the actual operation of a power plant more realistically, a semi-physical simulation is used to get as close to the real power plant as possible. In view of the fact that most existing semi-physical simulation systems of thermal power plants are based on PLC control systems, this simulation platform not only adopts the most advanced DCS control system, but also adds a condenser liquid level physical control object; based on the hardware-in-the-loop simulation mode, a DCS control system, a switch, a host computer, and peripheral condenser liquid level control equipment are added to the thermal power plant simulation system, which improves the degree of semi-physical simulation and can better reflect various complex industrial conditions during power plant operation control. The DCS control system includes: a DCS control cabinet, a control board, a power supply, etc.; the switch has the following functions: transmitting the status of the simulator to the host computer and displaying it on the host computer interface, and transmitting the control signal of the DCS control system to the simulator; the host computer acts as a display and operation machine, displaying the current operation and control status of the thermal power plant and capable of switching the controller and status; the condenser equipment is a peripheral control device, which transmits the liquid level signal to the DCS control system via a liquid level sensor, receives the control signal transmitted by the DCS control system, and acts on the inlet / outlet valve to dynamically control the liquid level. In the technical solution provided by the present invention, the actual operating conditions of the entire thermal power plant are simulated in the simulator, the thermal power plant status and control signals are transmitted to the host computer and DCS control system via the switch, and the control quantity is transmitted to the peripheral condenser liquid level control equipment via the DCS control system, thereby realizing dynamic control of the condenser liquid level. The innovation of the semi-physical simulation system of the present invention lies in that it not only utilizes the physical cabinet of the DCS control system and the physical water tank of the condenser, but also creatively combines the make-up pump and the water inlet pump into one, and applies the control quantity of the make-up pump to the water inlet pump, thereby reducing the number of water pumps and more realistically simulating the industrial process of power generation in a power plant.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A DCS simulation control system for a thermal power plant containing a physical object of a condenser, characterized in that: include: A power plant virtual simulator (1), a host computer (2), a switch (3), a DCS control system (5), and a condenser physical object (6); the switch (3) is used to realize data interaction among the power plant virtual simulator (1), the host computer (2), and the DCS control system (5); The power plant virtual simulator (1) is used to simulate the operating conditions of a thermal power plant and output the steam condensation amount and the condenser condensation amount; The host computer (2) is used to display the control effect of the thermal power plant DCS simulation control system; The DCS control system (5) is used to output the condenser water replenishment amount according to the liquid level information transmitted by the condenser physical object (6) and a preset liquid level threshold; The condenser physical object (6) includes a water inlet control valve, a water outlet control valve, a water tank, and a liquid level sensor; the liquid level sensor is used to obtain liquid level information of the water tank; wherein, the control signal of the water inlet control valve is obtained by the DCS control system (5) based on the steam condensation amount and the condenser water supply amount, and the control signal of the water outlet control valve is obtained by the DCS control system (5) based on the condensation amount of the condenser; in, The power plant virtual simulator (1) is used to simulate the operating conditions of a thermal power plant. Specifically, the power plant virtual simulator (1) is used to simulate the operating conditions of a thermal power plant based on the condenser feed water volume delivered by the DCS control system (5); The host computer (2) is used to display the control effect of the thermal power plant DCS simulation control system, including: the power plant virtual simulation machine (1) and the host computer (2) are connected by a relational database, the power plant operation data in the power plant virtual simulation machine (1) is transmitted to the host computer (2) through the JX Server, and the host computer (2) displays the power plant operation status on the established configuration interface; The host computer (2) is used to display the control effect of the DCS simulation control system of the thermal power plant, including: the DCS control system (5) obtains the liquid level information of the condenser physical object (6), and feeds the liquid level information back to the configuration interface of the host computer (2) through the DCS control system (5); The mathematical model of the condenser in the power plant virtual simulator (1) is: (1) Steam area: The mass conservation equation is Among them, W s is the steam volume on the shell side of the condenser, W nd is the steam turbine exhaust volume, W as is the amount of steam condensation, ρ s is the steam density; V is the volume of the steam and gas space of the condenser; The average enthalpy is Among them, H s is the average enthalpy of steam, H ed is the exhaust enthalpy of the steam turbine; Q s =W ed (H ed -C w T s )-(W ed -W as )(H s -C w T s ); P s =f(T s ); H s =f(T s ); r s =f(T s ); Where, T s is the average temperature of steam in the condenser, P s is the condenser pressure, Q s is the heat released by steam condensation, C w is the specific heat capacity of cooling water, T1 and T2 are the inlet and outlet temperatures of cooling water, α n is the convection heat release coefficient, S1 is the heat exchange area; (2) Hot well water area: Where W w is the water storage capacity of the hot well, W l is the condenser water output, L is the hot well water level, A is the hot well cross-sectional area, H as is the saturated water enthalpy at condenser pressure, H w is the enthalpy of hot well water; (3) Cooling water pipe model: Where M cw is the water storage capacity of the cooling water pipe, D w is the cooling water flow rate.

2. A DCS simulation control system for a thermal power plant containing a condenser physical object according to claim 1, characterized in that: Also includes: The remote control center is used to control the thermal power plant model of the power plant virtual simulation machine (1) based on the remote network and the switch (3).

3. A DCS simulation control method for a thermal power plant containing a physical condenser object, characterized in that: The DCS simulation control system for a thermal power plant according to claim 1 comprises the following steps: The power plant virtual simulator (1) simulates the operating conditions of the thermal power plant and outputs the steam condensation amount and the condenser condensation amount; The control effect of the DCS simulation control system of the thermal power plant is displayed by the host computer (2); Outputting the condenser water supply amount through the DCS control system (5) according to the liquid level information transmitted by the condenser physical object (6) and a preset liquid level threshold; Outputting liquid level information through the condenser physical object (6); The DCS control system (5) simulates and controls the water inlet control valve using a control signal obtained based on the steam condensation amount and the condenser water supply amount; and the DCS control system (5) simulates and controls the water outlet control valve using a control signal obtained based on the condensation amount of the condenser; Data interaction between the power plant virtual simulation machine (1), the host computer (2) and the DCS control system (5) is realized through the switch (3); in, The step of simulating the operating conditions of a thermal power plant by the power plant virtual simulator (1) comprises: simulating the operating conditions of a thermal power plant by the power plant virtual simulator (1) based on the condenser feed water amount delivered by the DCS control system (5); The step of displaying the control effect of the DCS simulation control system of the thermal power plant through the host computer (2) includes: the power plant virtual simulation machine (1) and the host computer (2) are connected by a relational database, the power plant operation data in the power plant virtual simulation machine (1) is transmitted to the host computer (2) through the JX Server, and the host computer (2) displays the power plant operation status on a configured interface that has been built; the DCS control system (5) obtains the liquid level information of the condenser physical object (6), and feeds the liquid level information back to the configuration interface of the host computer (2) through the DCS control system (5).

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