Turbine expansion unit operation training system and data interaction method thereof

Abstract

The invention relates to the field of system simulation, in particular to an operation training system of a turbine expansion unit and a data interaction method thereof, which comprise a simulation model of the turbine expansion unit, a control system model of the turbine expansion unit and a method for performing data interaction between the simulation model and the control system model. The control system model is a main body of control logic. According to the operation training system of the turbine expansion unit, the working characteristics of the turbine expansion unit can be known in advance, pre-verification of a control system is carried out, the control logic of the turbine expansion unit is debugged, the optimal coupling working point and the optimal operation method of the turbine expansion unit are searched, and an operator is trained.

Description

Technical Field

[0001] The present application relates to the field of system simulation, and in particular to an operation training system for a turbine expander unit and a data interaction method thereof. Background Art

[0002] With the development of science and technology, large cryogenic systems have been widely used in cutting-edge fields such as nuclear fusion, high-energy physics and superconducting systems, such as the European Organization for Nuclear Research's Large Hadron Collider (LHC), the International Thermonuclear Experimental Reactor (ITER) and the National Advanced Nuclear Fusion Experimental Device Superconducting Tokamak (EAST). The cryogenic turboexpander is a key component of a large hydrogen-helium cryogenic refrigerator, which achieves and maintains a low-temperature environment in the required temperature range through its expansion refrigeration. In addition, the turboexpander is also used in liquefaction devices to liquefy gases with extremely low boiling points, such as helium and hydrogen.

[0003] Large hydrogen-helium cryogenic refrigerators have large cooling capacity and complex processes, and usually need to be equipped with multiple turbine expanders with different flow rates and expansion ratios. For example, the 10kW@20K helium refrigerator developed by the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences is equipped with a turbine expander. The 250W@4.5K helium refrigerator developed by the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences is equipped with two turbine expanders. The 2500W@4.5K helium refrigerator developed by the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences is equipped with 4 groups of 6 turbine expanders. The 18kW@4.5K helium refrigerator being developed by the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences is equipped with 5 groups of 10 turbine expanders. When turbines work under multiple operating conditions and variable operating conditions, it is easy to deviate from the optimal design conditions. Multiple turbines are coupled with each other. In a multi-temperature zone and multi-pressure level environment, the requirements for coordinated control between multi-stage turbines are high.

[0004] The control of the turbine expander unit determines the performance of the large hydrogen-helium cryogenic refrigerator. Therefore, it is necessary to carry out research on the impeller mechanical coupling and coordinated control strategy under multiple operating modes of large hydrogen-helium cryogenic refrigerators. For the series and parallel connection of turbine expander units with different flow rates, expansion ratios, and characteristic ratios, it is particularly important to debug the control logic of the turbine expander unit, distribute the load of the turbine expander unit, and study the coupling characteristics and coordinated control strategy of the turbine expander unit under different operating modes to achieve the safe operation of large hydrogen-helium cryogenic refrigerators.

[0005] The OTS (Operation Training System) operation training system combines dynamic simulation and measurement and control system development technology to develop a front-end user operation interface, which is convenient for understanding the characteristics of the entire system and conducting operation training for staff before the system is put into operation.

[0006] Developing and utilizing an operator training system to train operators can avoid putting actual equipment in a dangerous situation. The operator training system can be run in certain special working conditions without worrying about serious consequences. For operators, they cannot distinguish whether they are facing a real system or a simulated system when facing the HMI human-machine interface.

[0007] The dynamic simulation model of the turbine expander is encapsulated, and the data of the dynamic simulation model of the turbine expander and the control system model of the turbine expander based on the PLC architecture are exchanged. The dynamic simulation of the turbine expander and the pre-verification and debugging of the control system can be performed without building an actual turbine expander. The main control logic of the turbine expander is debugged to find the optimal working point and the optimal operation method of the turbine expander coupling. Summary of the invention

[0008] The embodiment of the present application provides an operation training system for a turbine expander unit and a data interaction method thereof, so as to at least solve the technical problem that the existing turbine expander unit has poor safe operation.

[0009] According to an embodiment of the present application, there is provided an operation training system for a turbine expander unit, including a simulation model and a control system model; wherein:

[0010] The simulation model can help you understand the working characteristics of the turbine expander in advance, pre-verify the control system, and debug the control logic of the turbine expander.

[0011] The control system model is the main body of the control logic;

[0012] The operation training system finds the best working point and the best operation method of the turbine expander coupling, and trains the operators.

[0013] Furthermore, the simulation model is established based on the dynamic simulation software EcosimPro and compiled.

[0014] Furthermore, when establishing the simulation model, the characteristic curve equation of each turbine expander is customized, and the characteristic curve equation of each turbine expander is written into the source code of the turbine component, and is defined and packaged into a proprietary turbine model.

[0015] Furthermore, when establishing the simulation model, the internal variables simulation time time and error information error are respectively encapsulated into usable components.

[0016] Furthermore, when establishing a simulation model, the internal variable simulation time time is encapsulated into a simulation time component; the internal variable error information error is encapsulated into an error information component; the simulation time component outputs the simulation time value of the system, the variable type is real, and the analog output; the error information component outputs the error information value of the system, the variable type is real, and the analog output.

[0017] Furthermore, the simulation time component and the error information component are placed in the same screen as the main loop model of the turbine expander unit simulation model.

[0018] Furthermore, after the simulation model is compiled, a partition is generated. After the partition is successfully validated, a special experiment is established, the EL language code is written in the experiment, and the experiment is compiled and run.

[0019] Furthermore, based on the EL experiment code to generate the deck platform, first define the input and output variables, the input variables are the variables controlled by the third-party software, and the output variables are the various process values ​​calculated by the simulation model.

[0020] Furthermore, the input variables include: regulating valve opening, switch valve opening, boundary conditions and PID automatic casting; the boundary conditions include: load heating power, high-pressure inflow temperature, pressure and flow rate, low-pressure return flow temperature, pressure and flow rate; when the temperature, pressure and flow rate in the boundary conditions are used, any combination of the two is adopted;

[0021] The output variables include: simulation time time, error message error, temperature before and after each level of heat exchanger, pressure before and after each level of heat exchanger, flow before and after each level of heat exchanger, valve opening, temperature before and after valve, pressure before and after valve, flow before and after valve, temperature before and after each level of turbine, pressure before and after each level of turbine, flow before and after each level of turbine, speed of each level of turbine and efficiency of each level of turbine; among which error message error is an optional variable and can be selected when it exists.

[0022] According to another embodiment of the present application, a data interaction method of an operation training system using the above-mentioned turbine expander unit is provided, comprising:

[0023] Using the deck platform, the simulation model is packaged into a compilable C++ file; using the C++ program, the compilable C++ file is compiled into an executable file, the simulation model is run, and the running results are stored in the SQL database;

[0024] The PLC-based control system obtains the input and output data of the turbine expander unit simulation model operation in the SQL database and interacts with the simulation model.

[0025] The operation training system of the turbine expander unit in the embodiment of the present application and the data interaction method thereof include a simulation model of the turbine expander unit, a control system model of the turbine expander unit, and a method for data interaction between the simulation model and the control system model. The control system model is the main body of the control logic. The operation training system of the turbine expander unit can understand the working characteristics of the turbine expander unit in advance, perform pre-verification of the control system, debug the control logic of the turbine expander unit, find the optimal working point and the optimal operation method of the turbine expander unit coupling, and train the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0027] Figure 1 is a schematic flow chart of an operation training system for a turboexpander unit in one embodiment;

[0028] Figure 2 is a technical architecture diagram of an operator training system for a turbine expander unit applicable to one embodiment;

[0029] Figure 3 is a simplified flow diagram of a turboexpander unit applicable to one embodiment;

[0030] Figure 4 is a simplified flow diagram of another turboexpander unit applicable to one embodiment;

[0031] Figure 5 is a simplified flow diagram of another turboexpander unit applicable to one embodiment;

[0032] Figure 6 is a simplified flow diagram of another turboexpander unit applicable to one embodiment;

[0033] Figure 7 is a simplified flow diagram of another turboexpander unit applicable to one embodiment;

[0034] Figure 8 A technical roadmap for an operator training system for a turbine expander unit in one embodiment. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application 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 data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising 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.

[0037] The present application discloses an operation training system for a turbine expander unit and a data interaction method thereof, including a simulation model of the turbine expander unit, a control system model of the turbine expander unit, and a method for data interaction between the simulation model and the control system model. The operation training system for the turbine expander unit can understand the working characteristics of the turbine expander unit in advance, perform control system pre-verification, debug the control logic of the turbine expander unit, find the optimal working point and optimal operation method of the turbine expander unit coupling, and train operators.

[0038] The application operation training system adopts the following specific technical solutions to adapt to various types of turbine expansion units:

[0039] A turbine expansion unit. The present application is applicable to the following turbine expansion units, which are described by way of example respectively.

[0040] like Figure 3 The turbine expansion unit shown is composed of a single turbine TB1, a heat exchanger HEX1, a heat exchanger HEX2, a liquid nitrogen precooling valve CV1, a turbine inlet valve CV2, a turbine bypass valve CV3, and a load E-1.

[0041] The working process is as follows:

[0042] The high-pressure gas from the compressor station enters the cold box, passes through the first-stage heat exchanger HEX1, and exchanges heat in reverse with the liquid nitrogen from the liquid nitrogen pre-cooling circuit, and is pre-cooled to about 80K. After passing through the second-stage heat exchanger HEX2, most of it enters the turbine TB1, is expanded by the turbine and cooled to the target temperature. After passing through the load E-1, it passes through HEX2 in reverse flow, and HEX1 returns to low pressure.

[0043] The opening degrees of the turbine bypass valve CV3 and the turbine inlet valve CV2 are complementary. After TB1 is fully opened, the turbine bypass valve CV3 slowly closes.

[0044] The system structure is relatively simple, with only one turbine expander. When simulating the system, you can first customize the turbine characteristic curve equation, encapsulate it into a customized turbine model, and then build the system model.

[0045] Adjust various parameters of the custom turbine model and simulate the turbine expander under different parameters.

[0046] Set the boundary conditions of high-pressure inflow and low-pressure return flow to perform dynamic simulation of the turboexpander.

[0047] Figure 3 The input variables in include the opening of each regulating valve, the opening of each switch valve, each boundary condition, and each PID automatic. Specifically: the opening of the liquid nitrogen precooling inlet valve CV1, the opening of the turbine inlet valve CV2, the opening of the turbine bypass valve CV3, the heating power of the electric heater E-1, the liquid nitrogen LN precooling inlet temperature, pressure, flow (two out of the three), the gas nitrogen GN outlet temperature, pressure, flow (two out of the three), the high-pressure circuit inlet temperature, pressure, flow (two out of the three), the low-pressure circuit outlet temperature, pressure, flow (two out of the three). The liquid nitrogen precooling PID is automatically activated, the turbine inlet pressure PID is automatically activated, and the turbine outlet temperature PID is automatically activated.

[0048] Output variables include temperature, pressure, flow rate before and after each heat exchanger, opening of each valve, temperature, pressure, flow rate before and after each valve, temperature, pressure, flow rate before and after each turbine, speed of each turbine, and efficiency. Specifically: simulation time, error message error (optional, if the system has it). Liquid nitrogen LN precooling inlet and outlet temperature, pressure, flow rate, heat exchanger HEX1-HEX2 before and after temperature, pressure, flow rate, valve CV1-CV3 opening, valve CV1-CV3 before and after temperature, pressure, flow rate, E-1 heating power, turbine TB1 before and after temperature, pressure, flow rate, TB1 speed, TB1 efficiency, etc.

[0049] like Figure 4The turbine expansion unit shown is composed of turbine TB1, turbine TB2, heat exchangers HEX1~HEX5, liquid nitrogen precooling valve CV1, turbine inlet valve CV2, first-stage turbine bypass valve CV4, throttle valve CV3, and Dewar D4100.

[0050] The working process is as follows:

[0051] The high-pressure gas from the compressor station enters the cold box, passes through the first-stage heat exchanger HEX1, and reversely exchanges heat with the liquid nitrogen from the liquid nitrogen pre-cooling circuit, and is pre-cooled to about 80K. After passing through the second-stage heat exchanger HEX2, part of the high-pressure gas enters the first-stage turbine TB1, expands and cools to the target temperature, enters the second-stage turbine TB2 to expand and cool, and then returns to low pressure.

[0052] The first-stage turbine bypass valve CV4 is designed to match the rotational speeds of the first-stage turbine TB1 and the second-stage turbine TB2.

[0053] The other part of the gas in the high-pressure main circuit passes through the heat exchangers HEX3, HEX4, and HEX5 in sequence, and is throttled into gas-liquid two-phase by the throttle valve CV3, and enters the gas-liquid separator D4100. The liquid phase accumulates in D4100, and the gas phase returns to low pressure through the low-pressure circuit.

[0054] The low-pressure return air flows back through HEX5, HEX4, HEX3, HEX2, and HEX1, and then returns to the low-pressure suction port of the compressor station.

[0055] The system has two turbines TB1 and TB2, which are connected in series. When simulating this system, you can first customize the characteristic curve equation of each turbine, encapsulate it into a customized turbine model, and then build the system model.

[0056] Adjust various parameters of the custom turbine model to simulate the turbine expander under different parameters. Because there are two turbines in series, the parameters of the two turbines can be adjusted separately. Combined with the control of the first-stage turbine bypass valve CV4, the coupling of the two turbines is studied to find the optimal working point and the optimal operation method of the turbine expander unit coupling.

[0057] Set the boundary conditions of high-pressure inflow and low-pressure return flow to perform dynamic simulation of the turbine expander unit.

[0058] Figure 4The input variables in include the opening of each regulating valve, the opening of each switch valve, each boundary condition, and each PID automatic. Specifically: the opening of the liquid nitrogen precooling inlet valve CV1, the opening of the turbine inlet valve CV2, the opening of the turbine bypass valve CV4, the opening of the throttle valve CV3, the heating power of the electric heater in Dewar D4100, the liquid nitrogen LN precooling inlet temperature, pressure, flow (two out of the three), the gas nitrogen GN outlet temperature, pressure, flow (two out of the three), the high-pressure circuit inlet temperature, pressure, flow (two out of the three), the low-pressure circuit outlet temperature, pressure, flow (two out of the three). The liquid nitrogen precooling PID is automatically activated, the turbine TB1 inlet pressure PID is automatically activated, and the turbine TB2 outlet temperature PID is automatically activated. The electric heater in Dewar D4100 controls the D4100 liquid level PID automatically.

[0059] The output variables include the temperature, pressure, flow rate before and after each heat exchanger, the opening of each valve, the temperature, pressure, flow rate before and after each valve, the temperature, pressure, flow rate before and after each turbine, and the speed and efficiency of each turbine. Specifically: simulation time time, error message error (optional, if the system has it). Liquid nitrogen LN precooling inlet and outlet temperature, pressure, flow rate, HEX1-HEX5 before and after temperature, pressure, flow rate, valve CV1-CV4 opening, valve CV1-CV4 before and after temperature, pressure, flow rate, heating power of the electric heater in Dewar D4100, turbine TB1-TB2 before and after temperature, pressure, flow rate, TB1-TB2 speed, TB1-TB2 efficiency, Dewar D4100 temperature, pressure, liquid level, Dewar D4100 inlet and outlet flow, etc.

[0060] like Figure 5 The turbine expansion unit shown is composed of turbine TB1, turbine TB2, turbine TB3, heat exchangers HEX1, HEX3~HEX7, liquid nitrogen precooling valve CV1, liquid nitrogen tank D3100, liquid nitrogen precooling heat exchanger HEX2 immersed in the liquid nitrogen tank, turbine inlet valve CV2, first-stage turbine bypass valve CV6, turbine inlet valve CV3, turbine bypass valve CV4, throttle valve CV5, and Dewar D4100.

[0061] The working process is as follows:

[0062] The high-pressure gas from the compressor station enters the cold box, passes through the first-stage heat exchanger HEX1, and exchanges heat with the saturated nitrogen vapor from the liquid nitrogen pre-cooling circuit in reverse, then enters the liquid nitrogen tank D3100, passes through the heat exchanger HEX2 immersed in the liquid nitrogen tank for liquid nitrogen pre-cooling, and then enters HEX3. A portion of the high-pressure gas enters the turbine groups TB1 and TB2, expands and cools to the target temperature, and then returns to low pressure.

[0063] The first-stage turbine bypass valve CV6 is designed to match the speeds of the first-stage turbine TB1 and the second-stage turbine TB2.

[0064] The other part of the gas in the high-pressure main circuit passes through the heat exchangers HEX4, HEX5, and HEX6 in sequence, and then enters the final stage turbine TB3 for expansion and cooling again, and then passes through the throttle valve CV5 to throttle into gas-liquid two-phase, and enters the gas-liquid separator D4100. The liquid phase accumulates in D4100, and the gas phase returns to low pressure through the low-pressure circuit.

[0065] The final stage turbine spans across the high-pressure main line and acts as a booster to increase the system's cooling and liquefaction capacity. If the system has sufficient cooling capacity, the final stage turbine may not be turned on.

[0066] The low-pressure return air flows back through HEX7, HEX6, HEX5, HEX4, HEX3, and HEX1, and then returns to the low-pressure suction port of the compressor station.

[0067] The system has three turbines, of which TB1 and TB2 are connected in series. When simulating this system, you can first customize the characteristic curve equation of each turbine, encapsulate it into a customized turbine model, and then build the system model.

[0068] Adjust various parameters of the custom turbine model to simulate the turbine expander under different parameters. Because there are two turbines in series, the parameters of the two turbines can be adjusted separately. Combined with the control of the first-stage turbine bypass valve CV4, the coupling of the two turbines can be studied to find the optimal working point and the optimal operation method of the turbine expander unit. The coupling matching study of the third turbine and the first two turbines can also be carried out.

[0069] Set the boundary conditions of high-pressure inflow and low-pressure return flow to perform dynamic simulation of the turbine expander unit.

[0070] Figure 5 The input variables in include the opening of each regulating valve, the opening of each switch valve, each boundary condition, and each PID automatic. Specifically: the opening of the liquid nitrogen precooling inlet valve CV1, the opening of the turbine TB1 inlet valve CV2, the opening of the turbine bypass valve CV6, the opening of the turbine TB3 inlet valve CV3, the opening of the turbine TB3 bypass valve CV4, the opening of the throttle valve CV5, the heating power of the electric heater in Dewar D4100, the liquid nitrogen LN precooling inlet temperature, pressure, flow (two of the three), the gas nitrogen GN outlet temperature, pressure, flow (two of the three), the high-pressure circuit inlet temperature, pressure, flow (two of the three), the low-pressure circuit outlet temperature, pressure, flow (two of the three). Liquid nitrogen precooling PID automatic, turbine TB1 inlet pressure PID automatic, turbine TB2 outlet temperature PID automatic. Turbine TB3 inlet pressure PID automatic, turbine TB3 outlet temperature PID automatic. Dewar D4100 electric heater control D4100 liquid level PID automatic.

[0071] Output variables include the temperature, pressure, and flow rate before and after each heat exchanger, the opening of each valve, the temperature, pressure, and flow rate before and after each valve, the temperature, pressure, and flow rate before and after each turbine, and the speed and efficiency of each turbine. Specifically: simulation time time, error information error (optional, if the system has output). Liquid nitrogen LN precooling inlet and outlet temperature, pressure, and flow rate, HEX1-HEX7 before and after temperature, pressure, and flow rate, valve CV1-CV6 opening, valve CV1-CV6 before and after temperature, pressure, and flow rate, Dewar D3100 temperature, pressure, and liquid level, Dewar D3100 inlet and outlet flow rate, Dewar D4100 electric heater heating power, turbine TB1-TB3 before and after temperature, pressure, and flow rate, TB1-TB3 speed, efficiency, Dewar D4100 temperature, pressure, and liquid level, Dewar D4100 inlet and outlet flow rate, etc.

[0072] like Figure 6 The turbine expansion unit shown is composed of a first-stage turbine TB11, TB12, a second-stage turbine TB2, a third-stage turbine TB31, TB32, a fourth-stage turbine TB4, a heat exchanger HEX1, a liquid nitrogen precooling heat exchanger HEX2, heat exchangers HEX3~HEX8, a liquid nitrogen precooling valve CV8, a liquid nitrogen precooling gas path inlet valve CV1, a first-stage turbine inlet valve CV2, a second-stage turbine inlet valve CV3, a third-stage turbine inlet valve CV4, a fourth-stage turbine inlet valve CV5, a fourth-stage turbine bypass valve CV6, a throttle valve CV7, and a Dewar D4100.

[0073] The working process is as follows:

[0074] After the high-pressure gas from the compressor station enters the cold box, part of the gas passes through CV1 and enters the liquid nitrogen pre-cooling heat exchanger HEX2, where it exchanges heat in reverse with the liquid nitrogen from the liquid nitrogen pre-cooling path and is pre-cooled to about 80K.

[0075] The pre-cooled gas is mixed with the high-pressure main gas and enters the heat exchanger HEX3 for heat exchange and cooling. A part of the gas enters the first-stage turbines TB11 and TB12 for expansion and cooling, and then returns to the medium-pressure circuit.

[0076] After the remaining high-pressure gas passes through the heat exchangers HEX4 and HEX5 for heat exchange and cooling, a part of it enters the second-stage turbine TB2 for expansion and cooling, and then returns to the medium-pressure line.

[0077] After the remaining high-pressure gas passes through the heat exchanger HEX6 for heat exchange and cooling, a part of it enters the third-stage turbines TB31 and TB32 for expansion and cooling, and then returns to the low-pressure circuit.

[0078] The remaining high-pressure gas passes through the heat exchanger HEX7 for heat exchange and cooling, and then enters the final stage turbine TB4 for further expansion and cooling.

[0079] After expansion and cooling, the high-pressure gas passes through the heat exchanger HEX8 for further heat exchange and cooling, and is throttled into gas-liquid two-phase by the throttle valve CV7, and enters the gas-liquid separator D4100. The liquid phase accumulates in D4100, and the gas phase returns to the low pressure through the low-pressure line.

[0080] The final stage turbine spans across the high-pressure main line and acts as a booster to increase the system's cooling and liquefaction capacity. If the system has sufficient cooling capacity, the final stage turbine may not be turned on.

[0081] The low-pressure return air flows back through HEX8, HEX7, HEX6, HEX5, HEX4, HEX3, and HEX1, and then returns to the low-pressure suction port of the compressor station.

[0082] The system has 4 groups of 6 turbines. When simulating this system, you can first customize the characteristic curve equation of each turbine, encapsulate it into a customized turbine model, and then build the system model.

[0083] Adjust various parameters of the custom turbine model to simulate the turbine expander under different parameters. Because there are 4 groups of 6 turbines connected in series and parallel, the parameters of each turbine can be adjusted separately, combined with the control of the turbine inlet valve and the final turbine bypass valve, multiple turbine coupling studies are conducted to find the optimal working point and optimal operation method of the turbine expander unit coupling.

[0084] Set the boundary conditions of high-pressure inflow and low-pressure return flow to perform dynamic simulation of the turbine expander unit.

[0085] Figure 6The input variables in include the opening of each regulating valve, the opening of each switch valve, each boundary condition, and each PID automatic. Specifically: the opening of the liquid nitrogen precooling inlet valve CV8, the opening of CV1, the opening of the turbine TB11 inlet valve CV2, the opening of the turbine TB2 inlet valve CV3, the opening of the turbine TB31 inlet valve CV4, the opening of the turbine TB4 inlet valve CV5, the opening of the turbine TB4 bypass valve CV6, the opening of the throttle valve CV7, the heating power of the electric heater in Dewar D4100, the liquid nitrogen LN precooling inlet temperature, pressure, flow (two out of the three), the gas nitrogen GN outlet temperature, pressure, flow (two out of the three), the high-pressure circuit inlet temperature, pressure, flow (two out of the three), the medium-pressure circuit outlet temperature, pressure, flow (two out of the three), the low-pressure circuit outlet temperature, pressure, flow (two out of the three). The liquid nitrogen precooling PID is automatically activated, the turbine TB11 inlet pressure PID is automatically activated, and the turbine TB12 outlet temperature PID is automatically activated. Turbine TB2 inlet pressure PID is automatically set, turbine TB2 outlet temperature PID is automatically set. Turbine TB31 inlet pressure PID is automatically set, turbine TB32 outlet temperature PID is automatically set. Turbine TB4 inlet pressure PID is automatically set, turbine TB4 outlet temperature PID is automatically set. Dewar D4100 electric heater control D4100 liquid level PID is automatically set.

[0086] The output variables include the temperature, pressure, flow rate before and after each heat exchanger, the opening of each valve, the temperature, pressure, flow rate before and after each valve, the temperature, pressure, flow rate before and after each turbine, the speed of each turbine, and efficiency. Specifically: simulation time time, error message error (optional, if the system has it). Liquid nitrogen LN precooling inlet and outlet temperature, pressure, flow rate, HEX1-HEX8 before and after temperature, pressure, flow rate, CV1-CV8 opening, CV1-CV8 before and after temperature, pressure, flow rate. The heating power of the electric heater in Dewar D4100, the temperature, pressure, flow rate before and after turbine TB11-TB4, the speed of turbine TB11-TB4, efficiency, Dewar D4100 temperature, pressure, liquid level, Dewar D4100 inlet and outlet flow, etc.

[0087] like Figure 7The turbine expansion unit shown is composed of a first-stage turbine TB11, TB12, TB13, a second-stage turbine TB21, TB22, a third-stage turbine TB31, TB32, a fourth-stage turbine TB41, TB42, a fifth-stage turbine TB5, a heat exchanger HEX1, a liquid nitrogen tank D3100, a liquid nitrogen precooling heat exchanger HEX2 immersed in a liquid nitrogen tank, a liquid nitrogen precooling heat exchanger HEX2-1, heat exchangers HEX3~HEX9, liquid nitrogen precooling gas path inlet valves CV1, CV2, a liquid nitrogen path inlet valve CV3, a first-stage turbine inlet valve CV5, a second-stage turbine inlet valve CV6, a third-stage turbine inlet valve CV7, a fourth-stage turbine inlet valve CV8, a final-stage turbine inlet valve CV9, a final-stage turbine bypass valve CV10, a cold box bypass valve CV11, a throttle valve CV12, and a gas-liquid separator D4100.

[0088] The working process is as follows:

[0089] After the high-pressure gas from the compressor station enters the cold box, part of the gas passes through CV1, and after reverse heat exchange with the saturated nitrogen vapor from the liquid nitrogen pre-cooling line, it enters the liquid nitrogen tank D3100, and is pre-cooled with liquid nitrogen through the heat exchanger HEX2 immersed in the liquid nitrogen tank, and cooled to about 80K (liquid nitrogen pre-cooling). Or a stream of fluid is separated and enters the first-stage turbine expansion unit TB11, TB12, TB13, and is pre-cooled to 80K by the first turbine expansion unit (turbine expansion unit pre-cooling). The outlet of the first turbine expansion unit returns the gas to the medium pressure and countercurrently passes through the heat exchangers HEX3 and HEX1. Either liquid nitrogen pre-cooling or turbine expansion unit pre-cooling can be selected, and they cannot be performed at the same time;

[0090] The remaining high-pressure main line helium is cooled by the reflux cold helium through the fourth-stage heat exchanger HEX4, and part of the helium enters the second turbine expansion unit TB21, TB22, and is cooled from 75K to 50K. The outlet gas of the second turbine expansion unit is returned to the medium pressure and countercurrently passes through the heat exchangers HEX5, HEX4, HEX3 and HEX1.

[0091] After the high-pressure main gas passes through the sixth-stage heat exchanger HEX6, a part of it enters the third turbine expansion unit TB31, TB32, and is cooled from 23K to 15K. The helium gas at the outlet of the third turbine expansion unit is returned to the medium pressure and countercurrently passes through the heat exchangers HEX7, HEX6, HEX5, HEX4, HEX3 and HEX1;

[0092] After the remaining high-pressure main gas passes through the seventh-stage heat exchanger HEX7, part of the helium enters the fourth turbine expansion unit TB41, TB42, and is cooled from 14K to 6K. The outlet gas of the fourth turbine expansion unit is returned to low pressure, countercurrently passes through the heat exchangers HEX8, HEX7, HEX6, HEX5, HEX4, HEX3 and HEX1, and enters the suction port of the low-pressure compressor unit.

[0093] The remaining high-pressure main gas passes through the eighth-stage heat exchanger HEX8, and then enters the ninth-stage heat exchanger HEX9 after passing through the last-stage turbine TB5 to exchange heat with the return cold helium. The high-pressure main gas reaches a supercritical state. The supercritical helium is throttled into gas-liquid two-phase by the throttle valve CV12. The liquid phase accumulates in the gas-liquid separator D4100, and the gas phase returns to the low-pressure pipeline, countercurrently passes through the heat exchangers HEX9, HEX8, HEX7, HEX6, HEX5, HEX4, HEX3 and HEX1, and enters the suction port of the low-pressure compressor unit to complete the entire cycle.

[0094] The system has 5 groups of 10 turbines. When simulating this system, you can first customize the characteristic curve equation of each turbine, encapsulate it into a customized turbine model, and then build the system model.

[0095] Adjust various parameters of the custom turbine model and simulate the turbine expander under different parameters. Because there are 5 groups of 10 turbines connected in series and parallel, the parameters of each turbine can be adjusted separately. Combined with the control of the turbine inlet valve and the final turbine bypass valve, multiple turbine coupling studies are conducted to find the optimal working point and optimal operation method of the turbine expander unit coupling.

[0096] Figure 7 The input variables include the opening of each regulating valve, the opening of each switch valve, each boundary condition, and each PID automatic control. Specifically: opening of liquid nitrogen precooling inlet valve CV3, opening of CV1, opening of CV2, opening of CV4, opening of turbine TB11 inlet valve CV5, opening of turbine TB21 inlet valve CV6, opening of turbine TB31 inlet valve CV7, opening of turbine TB41 inlet valve CV8, opening of turbine TB5 inlet valve CV9, opening of turbine TB5 bypass valve CV10, opening of cold box bypass valve CV11, opening of throttle valve CV12, opening of gas nitrogen GN outlet check valve NV02, heating power of Dewar D4100 medium electric heater, liquid nitrogen LN precooling inlet temperature, pressure, flow rate (two out of the three), gas nitrogen GN outlet temperature, pressure, flow rate (two out of the three), high pressure line inlet temperature, pressure, flow rate (two out of the three), medium pressure line outlet temperature, pressure, flow rate (two out of the three), low pressure line outlet temperature, pressure, flow rate (two out of the three). Liquid nitrogen precooling PID is automatically set, turbine TB11 inlet pressure PID is automatically set, turbine TB13 outlet temperature PID is automatically set. Turbine TB21 inlet pressure PID is automatically set, turbine TB22 outlet temperature PID is automatically set. Turbine TB31 inlet pressure PID is automatically set, turbine TB32 outlet temperature PID is automatically set. Turbine TB41 inlet pressure PID is automatically set, turbine TB42 outlet temperature PID is automatically set. Turbine TB5 inlet pressure PID is automatically set, turbine TB5 outlet temperature PID is automatically set. Dewar D4100 electric heater control D4100 liquid level PID is automatically set.

[0097] The output variables include the temperature, pressure, and flow rate before and after each heat exchanger, the opening of each valve, the temperature, pressure, and flow rate before and after each valve, the temperature, pressure, and flow rate before and after each turbine, and the speed and efficiency of each turbine. Specifically: simulation time time, error information error (optional, if the system has it). Liquid nitrogen LN precooling inlet and outlet temperature, pressure, and flow rate, HEX1-HEX9 before and after temperature, pressure, and flow rate, CV1-CV12 opening, CV1-CV12 before and after temperature, pressure, and flow rate, Dewar D4100 electric heater heating power, turbine TB11-TB5 before and after temperature, pressure, and flow rate, TB11-TB5 speed, efficiency, Dewar D3100 temperature, pressure, liquid level, Dewar D3100 inlet and outlet flow, Dewar D4100 temperature, pressure, liquid level, Dewar D4100 inlet and outlet flow, etc.

[0098] The working process of the above turbine expander unit is described in detail here in order to illustrate the simulated object and the working process of the simulated object.

[0099] A simulation model of a turbine expander unit is based on the dynamic simulation software EcosimPro. Firstly, a simulation model of a turbine expander unit is established and compiled.

[0100] The characteristic ratio refers to the ratio of the circumferential speed at the turbine expander impeller inlet to the isentropic ideal speed of the turbine expander. When other parameters remain unchanged, it directly reflects the influence of the speed on the efficiency of the turbine expander. Turbine expander characteristic ratio v = U / C S , the circumferential speed U at the turbine expander impeller inlet is only related to the rotation speed, C S It is related to the thermodynamic parameters of the gas inlet and outlet when the turbo expander is running. The characteristic ratio of the turbo expander has a decisive influence on the efficiency of the turbo expander. The curve of the isentropic efficiency of the turbo expander changing with the characteristic ratio is called the characteristic curve.

[0101] Based on Figures 3 to 7 The process diagram of the turbine expander unit. When establishing the simulation model of the turbine expander unit, the required component models are developed as needed. The characteristic curve equation of each turbine expander can be customized, that is, the characteristic curve equation of each turbine expander is written into the source code of the turbine component, defined and encapsulated into a proprietary turbine model, so as to better adapt to actual conditions and specific working conditions.

[0102] Optionally, when establishing a simulation model of the turbine expander unit, the internal variables simulation time time and error information error are respectively encapsulated into available components. The internal variable simulation time time is encapsulated into a simulation time component. The internal variable error information error is encapsulated into an error information component. The simulation time component outputs the simulation time value of the system, the variable type is real, and the analog output. The error information component outputs the error information value of the system, the variable type is real, and the analog output.

[0103] The simulation time component and the error information component do not need to be connected to the main loop of the turbo expander simulation model. Simply place the simulation time component and the error information component and the main loop model of the turbo expander simulation model in the same screen. After the compilation is passed, it can run smoothly.

[0104] After the simulation model is compiled, a partition is generated. After the partition is successfully validated, a special experiment needs to be established, the EL language code is written in the experiment, and the experiment is compiled and run. Based on this EL experiment code, a deck platform is generated: first, the input and output variables are defined. The input variables are the variables that need to be controlled by the third-party software, and the output variables are the various process values ​​calculated by the simulation model.

[0105] Optionally, the time variable output by the simulation time component and the error variable output by the error information component are defined as output variables.

[0106] There are many more input variables and output variables, which are not listed here one by one.

[0107] See Figure 1 , Figure 2 , Figure 8 , the method for data interaction between the simulation model and the control system model:

[0108] Using the deck platform, the simulation model is packaged into a compilable C++ file. Using the C++ program, the compilable C++ file is compiled into an executable file, the simulation model is run, and the running results are stored in the SQL database.

[0109] The PLC-based control system obtains the input and output data of the turbine expander unit simulation model operation in the SQL database and interacts with the simulation model.

[0110] In this implementation, the PLC uses a virtual PLC, namely a PLC simulator.

[0111] This implementation method does not use PLC hardware and is more economical.

[0112] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0113] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0114] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0115] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0116] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0117] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc. Various media that can store program codes.

[0118] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An operation training system for a turbine expander unit, characterized in that: Including simulation model and control system model; among which: The simulation model understands the working characteristics of the turbine expander unit in advance, performs pre-verification of the control system, and debugs the control logic of the turbine expander unit; The control system model is the main body of the control logic; The operation training system finds the optimal working point and the optimal operation method of the turbine expansion unit coupling, and trains the operator.

2. The turboexpander unit operation training system according to claim 1, characterized in that: The simulation model is established and compiled based on the dynamic simulation software EcosimPro.

3. The turboexpander unit operation training system according to claim 2, characterized in that: When establishing the simulation model, the characteristic curve equation of each turbine expander is customized, and the characteristic curve equation of each turbine expander is written into the source code of the turbine component, and is defined and packaged into a proprietary turbine model.

4. The turboexpander unit operation training system according to claim 3, characterized in that: When establishing the simulation model, the internal variables simulation time time and error information error are respectively encapsulated into usable components.

5. The turboexpander unit operation training system according to claim 4, characterized in that: When establishing the simulation model, the internal variable simulation time time is encapsulated into a simulation time component; the internal variable error information error is encapsulated into an error information component; the simulation time component outputs the simulation time value of the system, the variable type is real, and the analog output; the error information component outputs the error information value of the system, the variable type is real, and the analog output.

6. The turboexpander unit operation training system according to claim 5, characterized in that: Place the simulation time component and the error information component in the same screen as the main loop model of the turbine expander unit simulation model.

7. The turboexpander unit operation training system according to claim 6, characterized in that: After the simulation model is compiled, a partition is generated. After the partition is successfully validated, a special experiment is established, the EL language code is written in the experiment, and the experiment is compiled and run.

8. The turboexpander unit operation training system according to claim 7, characterized in that: Based on the ELexperiment code generation deck platform, the input and output variables are first defined. The input variables are the variables controlled by the third-party software, and the output variables are the various process values ​​calculated by the simulation model.

9. The turboexpander unit operation training system according to claim 8, characterized in that: The input variables include: regulating valve opening, switch valve opening, boundary conditions and PID automatic casting; the boundary conditions include: load heating power, high-pressure inflow temperature, pressure and flow rate, low-pressure return flow temperature, pressure and flow rate; when the temperature, pressure and flow rate in the boundary conditions are used, any combination of the two is adopted; The output variables include: simulation time time, error message error, temperature before and after each level of heat exchanger, pressure before and after each level of heat exchanger, flow before and after each level of heat exchanger, valve opening, temperature before and after valve, pressure before and after valve, flow before and after valve, temperature before and after each level of turbine, pressure before and after each level of turbine, flow before and after each level of turbine, speed of each level of turbine and efficiency of each level of turbine; among which error message error is an optional variable and can be selected when it exists.

10. A data interaction method using the turboexpander unit operation training system of claim 1, characterized in that: include: Using the deck platform, the simulation model is packaged into a compilable C++ file; Use C++ program to compile the compilable C++ file into an executable file, run the simulation model, and store the running results in the SQL database; The PLC-based control system obtains the input and output data of the turbine expander unit simulation model operation in the SQL database and interacts with the simulation model.

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