Compressor unit gas path system dynamic mechanism modeling method and system

Abstract

The invention provides a dynamic mechanism modeling method and system for a compressor unit gas path system, and the method comprises the steps: building a compressor process model: building a compressor gas path system model according to a process flow, setting compressor parameters according to the design data of a compressor, and setting steam attributes according to the design conditions of a steam turbine; a virtual controller is established, a distributed control system (DCS) translates a control logic module of a compressor control system (CCS), gas circuit logic of a compressor unit is restored, control logic establishment of a simulation compressor unit gas circuit system is carried out, and the simulation compressor unit gas circuit system is established. Comprising steam turbine rotating speed control, anti-surge control, internal unit equipment control, unit safety interlocking and / or other auxiliary programs of the compressor unit. The compressor gas path system established by using the process simulation modeling platform software, the distributed control system DCS configuration software and the data communication software is high in simulation reduction degree, high in transportation processing speed and high in interactivity.

Description

Technical Field

[0001] The present invention relates to the technical field of compressor unit simulation, and in particular to a dynamic mechanism modeling method and system for a compressor unit gas path system. Background Art

[0002] The compressor unit is an important pressure system in the process industry, and the gas circuit system is its core component. In the actual production process, the compressor unit is often cumbersome to operate, and the radiated noise generated by the unit's operation causes great damage to the on-site operator's body. The compressor control system CCS (Compressor Control System) is an energy-saving automatic control system for the operation of the compressor unit. Based on the control characteristics of the compressor unit, it realizes the integration and automatic control of the compressor unit through a series of control programs. The operator can remotely control the compressor unit through the compressor control system CCS, which is a major advancement in the control technology of large compressor units. The compressor control system CCS system mainly includes load regulation, surge control, turbine speed control, internal unit equipment control, unit safety interlock, and other auxiliary programs, instrument monitoring of various units such as the shaft side, etc., to achieve stable control of the entire process of the compressor unit.

[0003] Learning the process flow and control logic of the gas circuit system is a prerequisite for being familiar with the operation of the compressor unit. OTS (Operator Training System) is a software model that combines computer simulation software to simulate the real production process and mainly serves the training and learning of operators. Its fields cover chemical, petrochemical, oil refining and other process industries. OTS uses computer simulation technology and configuration tools such as distributed control system DCS (Distributed Control System) simulation system to model and restore the compressor unit gas circuit system, providing operators with a safer and more effective training platform and opportunity. The degree of simulation and restoration of the compressor unit gas circuit system will directly affect the training effect of the operator, which is related to the safe and efficient production of the process industry. Therefore, it is very important for the process industry to simulate the compressor unit gas circuit system and its compressor control system CCS control system with high restoration.

[0004] At present, there are three main types of compressor unit simulation modeling strategies.

[0005] 1) Simple mathematical model simulation.

[0006] Simple mathematical model simulation usually only builds a partial mathematical model, lacks human-computer interaction, lacks connection with the actual process flow, and has a low degree of restoration.

[0007] For example, combining the characteristics of ground source heat pump air conditioner compressor, the adaptive fuzzy algorithm and PID algorithm are used to optimize the compressor simulation model to improve the control effect and efficiency of the simulated compressor. However, the simulation mathematical model is not closely related to the process flow, and the restoration degree is not high enough. (Shi Jianhua, Yang Jie, Simulation of Adaptive Fuzzy PID Control in Ground Source Heat Pump Air Conditioner Compressor System [J], Journal of Wuhan Polytechnic, 2016, 15(3):4. DOI:CNKI:SUN:WHZB.0.2016-03-017)

[0008] For example, in combination with the compressor performance equation, the mathematical model was built using the Modelica language and the Dymola compiler, and the compressed fluid simulation verification was performed. However, the mathematical model not only lacks a visual human-computer interaction interface, which is not conducive to operator training and learning, but also the simulation equation only stays at the mathematical fitting level, without combining the actual process, and the model only targets the compressor gas path compression process. (Wang Tingxing, Li Fangzhan, Meng Guang, et al., Modeling and simulation methods of compressor systems based on Modelica and Dymola [J], Gas Turbine Experiment and Research, 2004, 17(3):6. DOI:10.3969 / j.issn.1672-2620.2004.03.009.)

[0009] 2) Use configuration model software to simulate the working process of the compressor unit.

[0010] This type of simulation modeling is only combined with a certain process flow and cannot fully simulate the actual work of the compressor unit. It also has the problem of low degree of restoration.

[0011] For example, a compressor was built with the help of HYSYS dynamic module and the start-up process was studied, or the shutdown process was studied with the HYSYS dynamic module. However, these models only involve a single working condition, and the dynamic model has great limitations.

[0012] For example, the actual working state of the compressor unit is simulated by using iFIX 4.0 configuration software (Wang Li, Cai Wenxuan, Implementation of the teaching simulation system of reciprocating compressor unit [J], Coal Technology, 2011, 30(4):3. DOI:CNKI:SUN:MTJS.0.2011-04-100.), which realizes the teaching simulation of the unit gas circuit system and largely solves the training problem of operators who use and maintain the compressor unit. However, the underlying mechanism database is not perfect and is only fitted by mathematical models, which reduces the degree of simulation to a certain extent.

[0013] Some researchers have built a two-stage compression dynamic model using HYSYS software and studied the operation of the unit under various working conditions. The simulation model is more complete and more advanced (Wang Li, Cai Wenxuan, Implementation of a teaching simulation system for reciprocating compressor units [J], Coal Technology, 2011, 30(4):3. DOI:CNKI:SUN:MTJS.0.2011-04-100). Or, for example, the patent with announcement number CN115206152A develops a compressor unit simulation teaching system based on the combined model. But in general, this type of simulation strategy still lacks the program control module of the real production environment, such as the interlocking program, the start-stop logic program, etc., and the simulation restoration degree is not high enough.

[0014] 3) Simulation of the compressor unit program.

[0015] This type of simulation, such as the patent with announcement number CN208270980U, combines a compressor control system CCS and a simulation controller to simulate a turbine compressor unit, but it lacks a complete process, which is not conducive to the operator's understanding of the system process.

[0016] In short, there is still much room for improvement in the simulation strategy of compressor unit gas circuit in terms of model or program restoration. The improvement of its strategy is conducive to further improving people's understanding of the operating procedures of the compressor unit gas circuit system and improving the professional ability of operators more efficiently. Summary of the invention

[0017] On the basis of the existing simulation research on the gas circuit system of a compressor unit, the present invention adopts virtual simulation technology to provide a dynamic mechanism modeling strategy of the gas circuit system of a compressor unit with high mechanism, program and restoration degree, so as to solve the problems of low simulation degree and unfriendly human-computer interaction. For this purpose, the following technical solutions are provided:

[0018] In a first aspect, the present invention provides a method for modeling a dynamic mechanism of a compressor unit gas circuit system, comprising:

[0019] Build a compressor process model, including establishing a compressor gas path system process model according to the process flow, setting compressor parameters according to compressor design data, and setting steam properties according to turbine design conditions;

[0020] Build a virtual controller to realize the control logic of the gas circuit system of the simulated compressor unit, including building a turbine speed logic module to control the turbine speed; building a turbine power association module to associate the turbine speed with the turbine output power; building a compressor output power module to establish a dynamic balance between the work done by high-pressure steam in the turbine and the mechanical energy of the compressor; building a compressor start-stop program module that can self-identify the corresponding start-stop stage according to the turbine speed and state conditions; building a compressor first and second stage surge valve program module for anti-surge control; building an interlocking program and other auxiliary modules;

[0021] The data of the compressor process model is transmitted between the virtual controller to realize the dynamic mechanism modeling of the compressor unit gas path system.

[0022] In a second aspect, the present invention provides a dynamic mechanism modeling system for a compressor unit gas circuit system, comprising:

[0023] Compressor process simulation model, used to build a compressor process model in the simulation modeling platform based on design data;

[0024] Data communication module, used to establish communication between the distributed control system DCS and the compressor control system CCS configuration bit number and the compressor process simulation model data to achieve two-way data transmission;

[0025] The virtual controller is used to simulate the operation of the simulation controller, realize the compressor control logic operation, and feed back the data to the distributed control system DCS and the compressor control system CCS monitoring screen.

[0026] Beneficial effects of the present invention:

[0027] 1) The present invention utilizes process simulation modeling platform software, distributed control system DCS configuration software and data communication software to build a compressor gas circuit system with high simulation degree, including the construction of underlying mechanism model and the translation of compressor control system CCS program. At the bottom of the process simulation modeling platform, the mathematical equations that need to be satisfied by the built-in equipment are built to achieve high simulation degree of the compressor group gas circuit system.

[0028] 2) The present invention provides a compressor control system CCS human-computer interaction interface that restores the actual compressor unit gas path system, thereby improving the friendliness of the human-computer interaction screen.

[0029] 3) The present invention can simulate various working conditions of the compressor unit gas circuit system, thereby improving the authenticity and applicability of the simulation model.

[0030] 4) The present invention restores the input and output of each signal of the compressor unit gas circuit system by establishing a virtual controller, thereby improving the degree of simulation restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flow chart of a dynamic mechanism modeling method for a compressor unit gas circuit system provided by an embodiment of the present invention;

[0032] Figure 2 It is a characteristic curve diagram of a compressor model. Among them, curves 1 to 4 are characteristic curve diagrams of a compressor at speeds of 5919, 6248, 6577, and 6906 rpm respectively;

[0033] Figure 3 The efficiency curve of a compressor model. Curves 1 to 4 are the efficiency curves of a compressor at speeds of 5919, 6248, 6577, and 6906 rpm respectively;

[0034] Figure 4 The characteristic curve diagram of the two-stage compressor model. Among them, curves 1 to 4 are the characteristic curve diagrams of the two-stage compressor at speeds of 5919, 6248, 6577, and 6906 rpm respectively;

[0035] Figure 5 The efficiency curve of the two-stage compressor model. Curves 1 to 4 are the efficiency curves of the two-stage compressor at speeds of 5919, 6248, 6577, and 6906 rpm respectively;

[0036] Figure 6 It is the module diagram of the steam turbine gas speed valve logic control program;

[0037] Figure 7 Customize program screen for compressor speed regulation;

[0038] Figure 8 This is a system architecture diagram for dynamic mechanism modeling of the compressor unit gas circuit system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0040] Terminology explanation:

[0041] OTS: Operator Training System, which is a software model that combines computer simulation software to simulate the real production process and mainly serves the training and learning of operators. Its fields cover various process industries such as chemical, petrochemical, and refining.

[0042] Compressor Control System CCS: Compressor Control System, based on the control characteristics of the compressor unit, realizes integrated and automated control of the compressor unit through a series of control programs.

[0043] Distributed Control System (DCS): Distributed Control System (DCS) combines network communication technology, computer technology, etc. to collect data from all parts of the factory, transmit it to the central control system through the communication bus, and provide real-time feedback based on the situation. It is an important tool for process industry monitoring, operation and management.

[0044] Valve Cv value: The flow coefficient of the valve. Generally speaking, the Cv of the switch valve is constant, and the Cv of the regulating valve can generally be calculated according to the formula For a simple estimate, F is the flow rate, OP is the valve opening, and △P is the pressure drop before and after the valve at a specified opening.

[0045] Embodiment 1:

[0046] See also Figure 1 This embodiment provides a dynamic mechanism modeling method for the gas path system of a compressor unit. The specific implementation method of the gas path simulation of the compressor unit mainly includes two parts: the construction of the turbine compressor process model and the compressor control logic configuration. Data is transmitted between the compressor process model data and the compressor control logic configuration to realize the dynamic mechanism modeling of the gas path system of the compressor unit. The specific implementation contents of the two parts are described in detail below.

[0047] S1, the compressor process simulation model is built based on the process flow chart of the compressor gas path. The specific process is:

[0048] S101, establishing a compressor gas path system model according to the process flow.

[0049] The gas circuit system is the main process flow of the compression part. The steam turbine mainly provides the power source for the compressor. The medium-pressure steam impacts the turbine to generate power to drive the compressor to rotate. After energy conversion, the medium-pressure steam becomes turbine condensate discharge. The gas circuit system process model includes the turbine compressor model, heat exchanger, interstage condensate tank, anti-surge valve, expander, condensate tank, vacuum pump and other main equipment. By integrating the above equipment models, performing dynamic simulation analysis, and simulating the performance of the system under different working conditions, a complete turbine compressor gas circuit system model can be established to analyze and optimize the performance of the compressor.

[0050] The gas circuit system model will help understand and predict the behavior of the compressor under different working conditions, and provide theoretical support for practical engineering design and operation. In this embodiment, the gas circuit system model is that the raw oil gas of 0.2MPa (G) enters the first compressor through the inlet regulating valve to 0.6MPa (G), and then passes through the cooler to cool to 40°C, and then enters the compressor inter-stage condensate tank for separation; the first stage is equipped with an anti-surge valve FZT31202, and is mixed with the raw oil gas before returning to the first compressor. The rich gas enters the second stage of the compressor from the top of the condensate tank and is further compressed to 1.4MPa (G), and finally sent to the subsequent process flow through the outlet regulating valve; the second stage is equipped with an anti-surge valve FZT31202 and returns to the outlet of the first compressor. According to the above process flow, a compressor gas circuit system model is established.

[0051] S102, setting compressor parameters according to compressor design data.

[0052] The parameters of the first stage compressor are set according to the compressor design data. In this embodiment, the maximum speed of the first stage compressor is set to 9500 rpm. The characteristic curve and efficiency curve are shown in the attached figure. Figure 2 and 3 As shown. Among them, Figure 2 Curves 1 to 4 are characteristic curves of a compressor at speeds of 5919, 6248, 6577, and 6906 rpm, respectively; Figure 3 In the figure, curves 1 to 4 are efficiency curves of a compressor at speeds of 5919, 6248, 6577, and 6906 rpm, respectively;

[0053] The parameters of the two-stage compressor are set according to the compressor design data. In this embodiment, the maximum speed of the two-stage compressor is set to 9500rpm. The characteristic curve and efficiency curve are shown in the attached figure. Figure 4 and 5 As shown. Among them, Figure 4 Curves 1 to 4 are characteristic curves of the two-stage compressor at speeds of 5919, 6248, 6577, and 6906 rpm, respectively; Figure 5 In the figure, curves 1 to 4 are the efficiency curves of the two-stage compressor at speeds of 5919, 6248, 6577, and 6906 rpm respectively.

[0054] S103, setting the properties of the steam according to the turbine design conditions.

[0055] The properties of steam are set according to the turbine design conditions. Different steam grades provide different power. The properties of steam include pressure, humidity, temperature, specific volume, etc. In this model, the boundary steam pressure on the turbine side is 2MPa (G). The turbine side mainly drives the turbine shaft to rotate and drives the compressor rotor to rotate at high speed through 2MPa medium-pressure steam, generating centrifugal force, thereby increasing the rich gas pressure. The speed of the compressor is controlled by a steam speed regulating valve (SIC1742). There is only energy transfer between the turbine and the compressor, which is the driving end of the first and second stage compressors. After cooling, the exhaust gas from the turbine becomes condensate and enters the condensate tank. At the same time, the non-condensable gas is discharged out of the boundary through the vacuum system.

[0056] S2: Compressor control logic configuration is the control logic module of the compressor control system CCS translated by the distributed control system DCS. It restores the gas path logic of the compressor unit and can realize the start-up, shutdown and anti-surge control of the compressor to ensure the safe and efficient operation of the compressor.

[0057] The control logic of the compressor control system CCS mainly includes the turbine speed control, anti-surge control, internal unit equipment control, unit safety interlock, and other auxiliary programs, instrument monitoring of various parts of the unit such as the shaft side, etc., to achieve stable control of the entire process of the compressor unit.

[0058] Combined with the control logic of the on-site compressor control system CCS, and using the distributed control system DCS configuration software, supplemented by the built-in custom program of the operator training system OTS, the control logic construction plan of the compressor unit gas circuit system is as follows:

[0059] S201, build a turbine speed logic module to control the turbine speed.

[0060] Using the general PID algorithm, the measured value is the turbine speed N, and compared with the speed control set point SV to calculate the deviation e. In each execution cycle, the speed control PID calculates the speed control response value CRN based on the deviation e. The speed control response value CRN is then sent to the output response selection module for selection with other control outputs, and finally acts on the speed control valve to adjust the turbine speed.

[0061] The speed control set point (SV) is selected based on the configuration and current operating mode. When in the automatic start or stop sequence control process, the automatic sequence control logic will automatically generate a local set point. In normal operation, the operator selects the local or remote set point.

[0062] The local set point mode includes RUN state and non-RUN state. In RUN state, the operator selects the local set point mode by pressing the local button. In non-RUN state, the controller automatically selects the local set point mode. In local mode, the range of the local set value depends on the state of the speed controller. Among them, during the automatic sequence control process (start or stop), the local set value is automatically generated by the sequence control logic. For example: in the speed increase and standby state, the variable range of the local set value is between the minimum control speed and the minimum speed governor control speed. In the stop state, the variable range of the local set value is between the minimum control speed and the maximum speed governor control speed. In the running state, the variable range of the local set value is between the minimum speed control speed and the maximum speed control speed. The adjustment of the local set point can be increased or decreased by pressing the speed increase button and the speed decrease button to increase or decrease the speed set value, or it can be set by setting the target value command (SV). When the speed increase or speed decrease button is pressed, the set point will jog up or down at the configured rate.

[0063] Specifically in this embodiment, a cascade PID control system is established to realize the control of the turbine speed, including establishing an inlet pressure control PID and a speed PID for cascade control. The output of the speed PID is used as the input of the main steam valve manual operator (MANUAL), which can realize the manual and automatic mode control of the speed.

[0064] The output of the handheld operator is connected to the compressor speed control 048_SIC_31602. Among them, PIC31202 is the pressure control controller of the compressor inlet, SpeedPID1 is the DCS speed control module of the steam turbine, and 049ZQM is the opening control module of the gas speed valve; the DCS logic program diagram of the distributed control system is as shown in the attached Figure 6 , showing the connection and logical relationship between various modules.

[0065] S202, building a steam turbine power correlation module to correlate the speed of the steam turbine with the output power of the steam turbine;

[0066] There is a close relationship between the speed and power of a steam turbine. Under a certain load, the speed of a steam turbine is relatively stable. When the load increases, the power output of the steam turbine will also increase accordingly, but the speed will decrease slightly.

[0067] In this embodiment, the steam turbine uses an expander, and the Cv value and expansion coefficient are set according to the steam turbine design data table and the logistics balance data. The isentropic efficiency in the expander model is set to 1, and the Cv value is set to 100. Therefore, the steam input can be adjusted according to the real-time speed and power demand to maintain stable operation of the steam turbine.

[0068] S203, building a compressor output power module, correlating the output power of the two compressors with the corresponding rotation speed by multiplying the turbine output power by a proportional coefficient, establishing a dynamic balance relationship between the work done by the high-pressure steam in the turbine and the mechanical energy of the compressor, and ensuring energy conservation of the system;

[0069] The output power proportionality coefficients of the steam turbine and the two-stage compressor can be customized according to the actual situation. The proportionality coefficients are not limited to constants, and can also be functions or characteristic curves. The specific procedures are as shown in the attached Figure 7 As shown. Among them, R1 refers to the output power of the first stage of the compressor, R2 refers to the output power of the second stage of the compressor, P refers to the output power of the turbine, PC is the state of the turning motor, OP is the opening of the turbine air speed valve, st1, st2, st3 are VI31401, VI31402, VI31403 respectively, st1 represents the switch state of the medium-pressure steam inlet stop valve, st2, st3 represent the quick-opening valves at the turbine inlet.

[0070] S204, build a start-stop program module for the compressor, build a speed control mode program according to the compressor speed increase curve, so that it can self-identify the corresponding start-stop stage according to the turbine speed and state conditions, and automatically or manually start the machine in the order of reaching the start condition, first stage warm-up, second stage warm-up, critical acceleration, normal acceleration, and normal operation. In addition, the speed control mode program also has an overspeed mode and a shutdown mode. Among them, the self-identified state conditions include but are not limited to the start condition and the interlocking condition.

[0071] Specifically, in the critical acceleration stage, the speed increase rate is higher than that of other links; different starting methods can be selected. In automatic mode, the machine automatically starts according to the preset program to reach the minimum speed value of the compressor. In manual mode, a judgment prompt is made after each step of the preset program conditions are met, that is, whether to proceed to the next step; only after the compressor reaches normal operating state, the user's speed adjustment input box permission is opened, and the input value can only be between the minimum speed of the compressor and the electronic trip rate.

[0072] In overspeed mode, the actual speed of the compressor must not exceed the electronic trip speed of the compressor, otherwise the electronic trip interlock will be triggered.

[0073] S205: Build the compressor first and second stage surge valve program modules for anti-surge control, which includes surge line drawing, surge detection, surge spiral point, and surge PID control.

[0074] (1) Anti-surge line drawing: Determine the X and Y axis coordinates of the surge line based on the compressor design data. The X axis is the ratio of the compressor inlet flow to the inlet flow multiplied by 100, and the Y axis is the compression ratio, that is, the compressor outlet pressure to the inlet pressure. Take the surge point coordinates at 5919, 6248, 6577, and 6906 rpm on the performance curve and convert them into the required surge line. Generally, the surge line is set with a certain safety margin (7-10%), which is called the anti-surge line. For example, if the safety margin is set to 10%, by shifting the surge line 10 units to the right, the anti-surge line, also called the surge control line, is obtained.

[0075] (2) Surge detection: After the surge line is drawn, the actual operating point is determined, that is, the determined inlet or outlet flow and compression ratio of the compressor at the current speed. When the operating point is calculated, it will be displayed in the surge line coordinate system. The actual margin is the horizontal coordinate of the operating point minus the horizontal coordinate of the surge point at the current speed. When the actual margin is less than the safety margin, the anti-surge valve opens quickly, otherwise it will close slowly. When the operating point crosses the surge line, the system determines that a surge is triggered, and it will count. At the same time, the anti-surge line will move down. For each surge, it will move down by 2 (2%) fine-tuning amount, and the maximum fine-tuning number is 10.

[0076] (3) Surge hovering point: The hovering point is defined as the safety margin minus the surge hovering margin (the surge hovering margin k1HOVER is generally set to 5), and the surge hovering slope klHOVER is set to 3 (% / secs). When the current operating point is close to the surge line, the hovering control point setting and the surge control line low are selected as the new operating point setting point, that is, the minimum hovering point will not be lower than the control line.

[0077] (4) Surge PID control: Control is performed by calculating the deviation between the circling point and the operating point. The PID control parameters are set in reverse mode. The controller slow-off function is set. The slow-off slope is set to 2 (% / sec). The amplification factor and the integral time are adjusted by the self-tuning function. If the actual margin exceeds the control line operation margin, the proportional function is doubled and the integral time is set to 1 / 4.

[0078] Specifically, in this embodiment, the model operation point is calculated by the first and second stage inlet flow rates, and then the surge curves of the compressor are compared and a safety margin is given to control the opening of the anti-surge valve.

[0079] Among them, the surge curve is obtained according to the designed standard molar flow and the inlet and outlet pressure ratio fitting curve of the first and second stages of the compressor. The general processing method is to obtain several points on the performance curve through image point acquisition software (such as Engauge Digitizer software). It is recommended to obtain more than 10 points to ensure the fidelity of the curve fitting.

[0080] The safety margin value can be automatically corrected according to the actual surge times. By default, the safety margin value will automatically increase by 2 after a surge occurs, and the maximum increase is 5 times, that is, the maximum margin automatically increases by 10. The safety margin can be returned to the initial safety margin by pressing the reset button.

[0081] S206: Build interlocking program and other auxiliary modules;

[0082] The interlocking program is built according to the actual interlocking requirements, including but not limited to the start-up condition interlocking, shutdown interlocking, and common interlocking program; other auxiliary modules are built according to the actual process requirements, including but not limited to the hydrocarbon pump self-starting program, warm-up timing program, and inter-stage separation tank liquid level step-by-step control program.

[0083] S207: Using the screen configuration of the real distributed control system DCS and the compressor control system CCS as a template, restore the simulation interaction screen.

[0084] The dynamic mechanism modeling method of the compressor group gas circuit system based on virtual simulation technology provided by the present invention is more in line with the actual production conditions through mechanism and dynamic modeling; in addition, the simulation strategy is fully compatible with the distributed control system DCS configuration, directly adopts the original distributed control system DCS configuration, and does not affect the real configuration control system, which not only ensures safety but also highly restores the real production environment; for third-party configuration software such as the compressor control system CCS, the simulation strategy uses the distributed control system DCS configuration to translate and restore its internal program one-to-one, completely restoring the real logic; the simulation uses the real production compressor control system CCS and distributed control system DCS screen, completely restoring the human-computer interaction interface; the maximum computing speed of the simulation modeling can reach 50 times the speed, which improves the efficiency of operator training and learning. In short, the simulation strategy has a higher degree of simulation restoration, a faster transportation processing rate, and stronger interactivity, which is conducive to the improvement of the professional ability of process operators.

[0085] Embodiment 2:

[0086] See also Figure 8 This embodiment provides a compressor group gas circuit system dynamic mechanism modeling system, which is used to implement the compressor group gas circuit system dynamic mechanism modeling method in embodiment 1. The system architecture includes a compressor process simulation model, a virtual controller, a distributed control system DCS monitoring and a compressor control system CCS monitoring. Specifically,

[0087] Compressor process simulation model, used to build a compressor process model in the simulation modeling platform based on design data;

[0088] Data communication module, used to establish communication between the distributed control system DCS and the compressor control system CCS configuration bit number and the compressor process simulation model data to achieve two-way data transmission;

[0089] The virtual controller is used to simulate the operation of the simulation controller, realize the compressor control logic operation, and finally feed back the data to the distributed control system DCS and the compressor control system CCS monitoring screen.

[0090] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A dynamic mechanism modeling method for a compressor unit gas circuit system, characterized in that: include, Build a compressor process model, including establishing a compressor gas path system process model according to the process flow, setting compressor parameters according to compressor design data, and setting steam properties according to turbine design conditions; Build a virtual controller to realize the control logic of the gas circuit system of the simulated compressor unit, including building a turbine speed logic module to control the turbine speed; building a turbine power association module to associate the turbine speed with the turbine output power; building a compressor output power module to establish a dynamic balance between the work done by high-pressure steam in the turbine and the mechanical energy of the compressor; building a compressor start-stop program module that can self-identify the corresponding start-stop stage according to the turbine speed and state conditions; building a compressor first and second stage surge valve program module for anti-surge control; and building an interlocking program and other auxiliary modules; The data of the compressor process model is transmitted between the virtual controller to realize the dynamic mechanism modeling of the compressor unit gas path system.

2. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1 is characterized in that: The gas circuit system process model includes a turbine compressor model, a heat exchanger, an interstage condensate tank, an anti-surge valve, an expander, a condensate tank and / or a vacuum pump.

3. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1 is characterized in that: The setting of compressor parameters according to the compressor design data includes setting parameters of a first-stage compressor according to the compressor design data, wherein the maximum speed of the first-stage compressor is set to 9500 rpm, and setting parameters of a second-stage compressor according to the compressor design data, wherein the maximum speed of the second-stage compressor is set to 9500 rpm.

4. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1 is characterized in that: The control logic of building a simulated compressor group gas path system also includes restoring the simulated interactive screen using the screen configuration of the real distributed control system DCS and the compressor control system CCS as a template.

5. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1, characterized in that: The steam turbine speed logic module is constructed to control the steam turbine speed, including: Set PID parameters and configuration parameters, including minimum / maximum control speed; Measuring the turbine speed N in real time and comparing it with the speed control set point SV to calculate the deviation e, wherein the speed control set point (SV) is selected based on the configuration parameters and the current operation mode; According to the deviation e, the speed control response value CRN is calculated using the PID algorithm; Compare the speed control response value CRN with other control outputs and select the final output; The final output value is applied to the speed regulating valve to adjust the turbine speed; The above steps are repeated in each execution cycle to achieve closed-loop control.

6. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1, characterized in that: The output power module of the compressor is constructed by multiplying the output power of the turbine by a proportional coefficient to associate the output power of the two-stage compressors with the corresponding speed. The proportional coefficient of the output power of the turbine and the two-stage compressor can be customized according to actual conditions. The proportional coefficient includes but is not limited to a constant, and can also be a function or a characteristic curve.

7. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1, characterized in that: The compressor start-stop program module can self-identify the corresponding start-stop phases according to the turbine speed and status conditions. The self-identified status conditions include but are not limited to start conditions and / or interlocking conditions.

8. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1, characterized in that: The anti-surge control in the anti-surge control of the compressor first and second stage surge valve program modules includes: Calculate the model operating point through the first and second stage inlet flow rates; Compare the surge curves of the compressor and give a safety margin to control the opening of the anti-surge valve; the surge curve is obtained based on the designed standard molar flow and the compressor's first and second stage inlet and outlet pressure ratio fitting curve; the safety margin value can be automatically corrected according to the actual surge times.

9. The dynamic mechanism modeling method of the compressor unit gas circuit system according to claim 1, characterized in that: The interlocking program is constructed according to actual interlocking requirements, including but not limited to start-up condition interlocking, shutdown interlocking and / or common interlocking programs; other auxiliary modules are constructed according to actual process requirements, including but not limited to hydrocarbon pump self-starting program, warm-up timing program and / or inter-stage separation tank liquid level step-by-step control program.

10. A dynamic mechanism modeling system for a compressor unit gas circuit system, characterized in that: include, Compressor process simulation model, used to build a compressor process model in the simulation modeling platform based on design data; Data communication module, used to establish communication between the distributed control system DCS and the compressor control system CCS configuration bit number and the compressor process simulation model data to achieve two-way data transmission; The virtual controller is used to simulate the operation of the simulation controller, realize the compressor control logic operation, and feed back the data to the distributed control system DCS and the compressor control system CCS monitoring screen.

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