Semi-hardware dynamic simulation platform of low-temperature refrigeration system and data interaction method of semi-hardware dynamic simulation platform

Abstract

The invention relates to the field of system simulation, in particular to a semi-hardware dynamic simulation platform of a low-temperature refrigeration system and a data interaction method of the semi-hardware dynamic simulation platform, which comprise a simulation model of the low-temperature refrigeration system, a control system model of the low-temperature refrigeration system and a method for performing data interaction on the simulation model and the control system model. According to the semi-hardware dynamic simulation platform of the low-temperature refrigeration system, the thermodynamic performance of the low-temperature refrigeration system can be known in advance, the dynamic thermal load of the low-temperature refrigeration system is simulated, control program pre-verification is carried out, the main control logic of the low-temperature refrigeration system is debugged, and performance estimation of the low-temperature refrigeration system in different working modes is carried out.

Description

Technical Field

[0001] The present invention relates to the field of system simulation, and in particular to a semi-hardware dynamic simulation platform of a low-temperature refrigeration system 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 Large Hadron Collider (LHC) at CERN, the International Thermonuclear Experimental Reactor (ITER) and the National Advanced Nuclear Fusion Experimental Superconducting Tokamak (EAST). Currently, more than half of my country's large scientific facilities require the support of cryogenic technology, and eight systems under construction or in pre-research need to be equipped with large superfluid helium cryogenic systems.

[0003] The helium cryogenic refrigeration system in the temperature range of liquid hydrogen, liquid helium to superfluid helium refers to a low-temperature refrigeration system with a refrigeration temperature in the range of 1.8K to 20K and a refrigeration capacity of several hundred watts to more than 10,000 watts. It usually includes a room temperature helium compressor station and its high-precision oil filter, a helium refrigerator in the liquid hydrogen / liquid helium temperature range (including a multi-stage turbine expander, a multi-stage cryogenic heat exchanger and a JT throttle valve), a superfluid helium refrigerator and user loads (such as for cooling various large superconducting magnets and superconducting radio frequency cavities, etc.).

[0004] Large hydrogen-helium cryogenic refrigeration systems are complex and have high power consumption, so it is not suitable to improve their efficiency and stability through a large number of experiments. Dynamic simulation of cryogenic refrigeration systems can simulate dynamic heat loads under different working modes and variable conditions, reduce thermal shock to refrigerators, and estimate the performance of cryogenic refrigeration systems under different working modes, providing key guidance for the design of refrigerators and cryogenic distribution systems.

[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 cryogenic refrigeration system is encapsulated, and data is exchanged between the dynamic simulation model of the cryogenic refrigeration system and the control system model of the cryogenic refrigeration system based on the PLC architecture. It is possible to perform dynamic simulation and control system pre-verification and debugging of the cryogenic refrigeration system without building an actual cryogenic refrigeration system, debug the main control logic of the cryogenic refrigeration system, estimate the performance of the cryogenic refrigeration system under different working modes, and simulate the dynamic heat load of the cryogenic refrigeration system. It provides a reference basis for the actual operation and adjustment of the cryogenic refrigeration system, as well as training for operators.

[0008] Hardware-in-the-loop simulation HIL replaces the actual controlled object or other system components with a simulation model running on a computer, and the control unit or other components of the system are connected to the simulation model as a system to test the function of the control unit. Hardware-in-the-loop simulation can reduce the development cost of the system and shorten the development cycle. Therefore, hardware-in-the-loop simulation is increasingly being used in the development of various scenarios and has broad development prospects.

[0009] The hardware-in-the-loop simulation HIL technology is used to establish a semi-hardware dynamic simulation platform for the cryogenic refrigeration system. The control system based on the actual PLC collects standard electrical signals and interacts with the simulation model. In the semi-hardware dynamic simulation platform of the cryogenic refrigeration system, the PLC hardware and the NI board are directly connected using hard-wired I / O, and the signal transmission is reliable and fast. The hardware-in-the-loop HIL technology is used, and the actual PLC is used to perform multi-platform and multi-hardware joint simulation, with advanced technical routes. The actual PLC collects standard electrical signals to simulate the real field signal environment. Summary of the invention

[0010] The embodiment of the present invention provides a semi-hardware dynamic simulation platform of a low-temperature refrigeration system and a data interaction method thereof, so as to at least solve the technical problem that the existing low-temperature refrigeration system has poor effect in simulating the real signal environment on site.

[0011] According to an embodiment of the present invention, a semi-hardware dynamic simulation platform for a low-temperature refrigeration system is provided, including a simulation model and a control system model; wherein:

[0012] The simulation model is used to understand the thermodynamic performance of the cryogenic refrigeration system in advance, simulate the dynamic heat load of the cryogenic refrigeration system, and pre-verify the control program;

[0013] The control system model is the main body of the control logic;

[0014] The semi-hardware dynamic simulation platform is used to debug the main control logic of the cryogenic refrigeration system and to estimate the performance of the cryogenic refrigeration system under different working modes.

[0015] Furthermore, the semi-hardware dynamic simulation platform is also used to provide a reference for the actual operation adjustment of the low-temperature refrigeration system and to train operators.

[0016] Furthermore, when establishing a simulation model of a compressor station, the required component models are developed as needed; the compressor component model is customized, the performance characteristic curve of the compressor is written into the source code of the compressor component, and it is defined and packaged into a proprietary compressor model.

[0017] Furthermore, when establishing a simulation model of a turbine expander unit, the required component models are developed as needed; the characteristic curve equation of each turbine is customized, and the characteristic curve equation of each turbine is written into the source code of the turbine component, and defined and packaged into a proprietary turbine model.

[0018] Furthermore, when establishing a simulation model of a cold compressor unit, a cold compressor component model is developed as needed; during the simulation process, a computer-aided CFD method is used to calculate the spectrum curve of each cold compressor, and points are taken in the spectrum curve to specify the blockage line, pressure ratio vs. speed rp_vs_Nr, flow ratio vs. speed mr_vs_Nr, and efficiency vs. speed eta_vs_Nr parameters of each cold compressor, and these parameters are used to modify the source code and encapsulate it into a custom cold compressor model.

[0019] Furthermore, when establishing a simulation model of a low-temperature refrigeration system, the internal variables simulation time time and error information error are respectively encapsulated into usable 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 output is the simulation time value of the system, the variable type is real, and the analog output; the error information component output is the error information value of the system, the variable type is real, and the analog output.

[0020] Furthermore, after the simulation model is compiled, a partition is generated. After the partition is successfully validated, a special experiment needs to be established, and the EL language code needs to be written in the experiment; the experiment is compiled and run.

[0021] Furthermore, a deck platform is generated based on the EL experiment code: first, the input and output variables are 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.

[0022] According to another embodiment of the present invention, a data interaction method using the semi-hardware dynamic simulation platform of the low-temperature refrigeration system is provided, comprising:

[0023] Using the deck platform, encapsulate the simulation model into an fmu file and select the fmu file type that interacts with third-party software;

[0024] After the simulation model is packaged into an fmu file, it is placed in the NI simulator. The generated fmu file is deployed using third-party laboratory management software. After successful deployment, a standard electrical signal is generated and input and output through the NI hardware board.

[0025] Based on the actual PLC control system, the I / O is directly connected and hard-wired to the NI hardware board to collect the standard electrical signals output by the NI hardware board. At the same time, various commands and parameters are output to the simulation model by setting the values ​​of the input parameters on the human-machine interface of the control system host computer;

[0026] The simulation model packaged into fmu file runs on the NI simulator, and the third-party laboratory management software is used on the NI simulator to monitor the running status of the dynamic simulation model; on the workspace interface of Veristand, the control variable Model Command is used to control the start, pause and stop of the simulation model;

[0027] Based on the control system of the actual PLC, the human-machine interface runs on the upper workstation / PC. Through the human-machine interface on the upper computer, commands are sent to control the simulation model, and various process parameters of the simulation model are monitored at the same time; the actual PLC collects standard electrical signals, and the control program written based on the actual PLC, the hardware addresses of the input and output variables are the same as the hardware addresses of the input and output variables in the control program of the control system under the real field signal environment, simulating the real field signal environment to the greatest extent.

[0028] According to another embodiment of the present invention, a data interaction method using the semi-hardware dynamic simulation platform of the low-temperature refrigeration system is provided, comprising:

[0029] Using the deck platform, the simulation model is packaged into an fmu file that runs under the Linux operating system, and the fmu file type that interacts with third-party software is selected;

[0030] After the simulation model is packaged into an fmu file running under the Linux operating system, the fmu file is deployed to the lower computer using a third-party laboratory management software in the upper PC. After successful deployment, a standard electrical signal is generated and input and output are performed through the NI hardware board.

[0031] Based on the actual PLC control system, the I / O is directly connected and hard-wired to the NI hardware board to collect the standard electrical signals output by the NI hardware board. At the same time, various commands and parameters are output to the simulation model by setting the values ​​of the input parameters on the human-machine interface of the control system host computer;

[0032] The simulation model packaged into fmu file is deployed to the NI simulator using third-party laboratory management software on the host PC. At the same time, the third-party laboratory management software is used on the host PC to monitor the running status of the dynamic simulation model. On the workspace interface of Veristand, the control variable Model Command is used to control the start, pause and stop of the simulation model.

[0033] Based on the control system of the actual PLC, the human-machine interface runs on another upper workstation / PC. Through the human-machine interface on another upper computer, commands are sent to control the simulation model, and various process parameters of the simulation model are monitored at the same time; the actual PLC collects standard electrical signals, and the control program written based on the actual PLC, the hardware addresses of the input and output variables are the same as the hardware addresses of the input and output variables in the control program of the control system under the real field signal environment, simulating the real field signal environment to the greatest extent.

[0034] The semi-hardware dynamic simulation platform of the cryogenic refrigeration system in the embodiment of the present invention and the data interaction method thereof include a simulation model of the cryogenic refrigeration system, a control system model of the cryogenic refrigeration system, and a method for data interaction between the simulation model and the control system model. The semi-hardware dynamic simulation platform of the cryogenic refrigeration system can understand the thermodynamic properties of the cryogenic refrigeration system in advance, simulate the dynamic heat load of the cryogenic refrigeration system, perform control program pre-verification, debug the main control logic of the cryogenic refrigeration system, and perform performance estimation of the cryogenic refrigeration system under different working modes. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0036] Figure 1 A schematic flow chart of a semi-hardware dynamic simulation platform for a cryogenic refrigeration system in one embodiment;

[0037] Figure 2 is a technical architecture diagram of a semi-hardware dynamic simulation platform for a cryogenic refrigeration system applicable to one embodiment;

[0038] Figure 3 is a block diagram of a cryogenic refrigeration system suitable for use in one embodiment;

[0039] Figure 4 It is a technical architecture diagram of a semi-hardware dynamic simulation platform for a low-temperature refrigeration system in a first embodiment;

[0040] Figure 5 is a flow chart of a semi-hardware dynamic simulation platform for a low-temperature refrigeration system in a second embodiment;

[0041] Figure 6 It is a technical architecture diagram of a semi-hardware dynamic simulation platform for a low-temperature refrigeration system of the second implementation mode. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0043] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0044] The present invention discloses a semi-hardware dynamic simulation platform for a cryogenic refrigeration system and a data interaction method thereof, including a simulation model of the cryogenic refrigeration system, a control system model of the cryogenic refrigeration system, and a method for data interaction between the simulation model and the control system model. The semi-hardware dynamic simulation platform for the cryogenic refrigeration system can understand the thermodynamic properties of the cryogenic refrigeration system in advance, simulate the dynamic heat load of the cryogenic refrigeration system, perform control program pre-verification, debug the main control logic of the cryogenic refrigeration system, and perform performance estimation under different working modes of the cryogenic refrigeration system. It provides a reference basis for the actual operation adjustment of the cryogenic refrigeration system and trains operators. The semi-hardware dynamic simulation platform adopts actual PLC hardware and can simulate the real on-site signal environment of the cryogenic refrigeration system to the greatest extent.

[0045] The present invention adopts the following specific technical solutions:

[0046] A cryogenic refrigeration system, see Figure 3 the block diagram of the cryogenic refrigeration system.

[0047] The cryogenic refrigeration system in the present invention refers to a medium - large cryogenic refrigeration system, specifically a refrigerating machine in the liquid hydrogen temperature range above kilowatt - level, a refrigerating machine in the liquid helium temperature range above hundred - watt - level, and a helium liquefier above 20L / h. The above medium - large cryogenic refrigeration systems use helium as the refrigerant and are designed and assembled based on the Claude refrigeration cycle or the Collins refrigeration cycle. It consists of a compressor station in the normal temperature part, a heat exchanger group, a turbine expansion unit, and a J - T throttle valve in the low - temperature part, etc., which are assembled in a vacuum - insulated cold box, and a cryogenic storage tank or a user load connected through a cryogenic transmission pipeline.

[0048] The compressor station can be a piston - type, twin - screw type or centrifugal compressor; it can be a single compressor, or two compressors in series, or a combination of multiple compressors in series - parallel.

[0049] When establishing the simulation model of the compressor station, develop the required component models as needed. Customize the compressor component model, for example, write the performance characteristic curve of the compressor into the source code of the compressor component, define and encapsulate it into a proprietary compressor model, so as to better adapt to the actual situation and specific working conditions.

[0050] The helium refrigerating machine can be a helium refrigerating machine based on the Claude cycle, the modified Claude cycle, the Collins cycle with two - stage turbines, the Collins cycle with multi - stage (2 < n ≤ 6) turbines, or the combined cycle of the modified Claude cycle and the Collins cycle with multi - stage (2 < n ≤ 10) turbines.

[0051] The turbine expansion unit can be supported by a hydrostatic gas bearing, a hydrodynamic gas bearing, a ceramic bearing or a magnetic bearing; it can be a full - gas or gas - liquid two - phase turbine expander.

[0052] When establishing the simulation model of the turbine expansion unit, develop the required component models as needed. For example, customize the characteristic curve equation of each turbine, that is, write the characteristic curve equation of each turbine into the source code of the turbine component, define and encapsulate it into a proprietary turbine model, so as to better adapt to the actual situation and specific working conditions.

[0053] The cryogenic storage tank can be a liquid helium dewar for storing liquid helium; it can also be a cold - quantity test subsystem with an internal heater for simulating and testing the refrigerating capacity; it can also be a cryogenic distribution valve box for delivering low - temperature saturated helium gas to users or cooled loads for cooling.

[0054] User loads can be heat loads in the 2K / 4K temperature zone, heat loads in the 4.5-75K temperature zone, and heat loads in the 50-75K temperature zone. Generally speaking, heat loads in the 2K / 4K temperature zone mainly refer to the pre-cooling conditions, operating conditions, quench conditions, and other non-steady-state conditions of superconducting cavities, superconducting magnets, superconducting solenoids and other components in the refrigerator load in the 2K / 4K temperature zone; heat loads in the 4.5-75K temperature zone mainly refer to the pre-cooling conditions, operating conditions, quench conditions, and other non-steady-state conditions of couplers and other components in the refrigerator load in the corresponding temperature zone; heat loads in the 50-75K temperature zone mainly refer to the various conditions of components such as cold shields and current leads in the refrigerator load.

[0055] There are no ready-made component models for cryogenic refrigeration systems such as superconducting cavities, superconducting magnets, superconducting solenoids, and couplers in the cryogenic component library Cryolib of the dynamic simulation software EcosimPro, so user-defined development is required. After the model is developed, the model validity is verified.

[0056] As a low-temperature refrigeration system, the cold screen includes liquid nitrogen cold screen and other temperature zone cold screens. In the low-temperature component library Cryolib of the dynamic simulation software EcosimPro, an electric heater model can be selected to simulate the dynamic heat load of the cold screen.

[0057] As a low-temperature refrigeration system, the current lead has no ready-made component model in the low-temperature component library Cryolib based on the dynamic simulation software EcosimPro, and needs to be developed by the user. After the model is developed, the model validity needs to be verified.

[0058] After the component model is developed, dynamic simulation is performed based on different working modes, such as pre-cooling conditions, operating conditions, quench conditions and other non-steady-state conditions.

[0059] The superfluid helium refrigerator can be a combination of a Jiao-Tang throttle valve, a negative pressure heat exchanger, a cold compressor and a negative pressure room temperature pump, or a combination of a Jiao-Tang throttle valve, a negative pressure heat exchanger and a cold compressor, or a combination of a Jiao-Tang throttle valve, a negative pressure heat exchanger and a negative pressure room temperature pump group.

[0060] When establishing the simulation model of the cold compressor unit, the cold compressor component model is developed as needed. During the simulation process, the computer-aided CFD method can be used to calculate the spectrum curve of each cold compressor, and points can be taken in the spectrum curve to specify the blocking line, rp_vs_Nr (specific pressure ratio vs. speed), mr_vs_Nr (specific flow vs. speed), eta_vs_Nr (efficiency vs. speed) and other parameters of each cold compressor. These parameters can be used to modify the source code and encapsulate it into a custom cold compressor model, which can be closer to the actual situation and specific working conditions.

[0061] The negative pressure room temperature pump group can adopt an oil-free dry pump or an oil pump. It can be a single pump or multiple pumps connected in parallel to form a pump group.

[0062] The negative pressure compressor unit can realize direct gas compression from negative pressure to low pressure or negative pressure to medium pressure. It can be a single negative pressure compressor or multiple negative pressure compressors connected in parallel to form a unit.

[0063] A dynamic simulation model of a low-temperature refrigeration system is based on the dynamic simulation software EcosimPro. Firstly, a simulation model of a low-temperature refrigeration system is established and compiled.

[0064] When establishing a simulation model of a low-temperature refrigeration system, the component models of the low-temperature refrigeration system are developed as needed. For example, the simulation model of the compressor, the simulation model of the turbo expander, the simulation model of the low-temperature system heat load, the simulation model of the cold compressor, etc. can all be customized and developed as needed.

[0065] Dynamic simulation of low-temperature refrigeration system can simulate dynamic heat load under different working modes and variable working conditions, reduce thermal shock to refrigerator, and provide key guidance for the design of refrigerator and low-temperature distribution system. In order to accurately simulate the working conditions of low-temperature refrigeration system under actual working conditions, it is necessary to develop custom low-temperature component models according to needs when performing dynamic simulation of low-temperature refrigeration system, and then form a low-temperature system model for dynamic simulation, which can be closer to the actual situation.

[0066] Optionally, when establishing a simulation model of a low-temperature refrigeration system, 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.

[0067] The simulation time component and error information component do not need to be connected to the main circuit of the low-temperature refrigeration system simulation model. Simply place the simulation time component and error information component and the main circuit model of the low-temperature refrigeration system simulation model in the same screen. After the compilation is passed, it can run smoothly.

[0068] After the simulation model is compiled, a partition is generated. After the partition is successfully validated, a special experiment needs to be established and the EL language code is written in the experiment. Compile and run the experiment. 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.

[0069] Figure 3 The input variables in include the start signal of each compressor, the start signal of each pump group, the opening of each regulating valve, the opening of each switch valve, the power of each electric heater, the power of each load, and the automatic signal of each PID. Specifically: the start signal of the high-pressure compressor, the start signal of the low-pressure compressor, the start signal of the negative pressure compressor, and the start signal of the pump group. The automatic start of each PID of the compressor station, the automatic start of each PID of the turbine expansion unit, the automatic start of each PID of the cold compressor unit, the automatic start of each PID of the pump group, and the automatic start of each PID in each gas-liquid separator. The slide valve signal of the high-pressure compressor, the slide valve signal of the low-pressure compressor, and the slide valve signal of the negative pressure compressor. The opening of each regulating valve and the opening of each switch valve in the low-temperature refrigeration system. The power of each electric heater, the power of each load, etc.

[0070] Figure 3 The output variables in 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. The temperature, pressure, and flow rate before and after each cold compressor, the pressure ratio, speed, and efficiency of each cold compressor. The flow, head, speed, power, and efficiency of each pump. The temperature, pressure, and liquid level of each gas-liquid separator, the inlet and outlet flow rate of each gas-liquid separator, and the power of the internal electric heater of each gas-liquid separator. The power of each load, etc. Specifically: simulation time time, error information error (optional, if the system has it). The inlet and outlet temperature, pressure, and flow rate of the high-pressure compressor / low-pressure compressor / negative pressure compressor, the frequency and slide valve of the high-pressure compressor / low-pressure compressor / negative pressure compressor. The opening of each regulating valve, the inlet and outlet temperature, pressure, and flow rate of each regulating valve. The opening of each switch valve, the inlet and outlet temperature, pressure, and flow rate of each switch valve. The inlet and outlet temperature, pressure, and flow rate of each turbine, and the speed and efficiency of each turbine. The inlet and outlet temperature, pressure, and flow rate of each cold compressor, and the pressure ratio, speed, and efficiency of each cold compressor. The flow rate, head, speed, power and efficiency of each pump. The temperature, pressure and flow rate before and after each heat exchanger. The temperature, pressure and liquid level of each gas-liquid separator, the inlet and outlet flow rate of each gas-liquid separator. The power of the electric heater inside each gas-liquid separator. The power of each load, etc.

[0071] 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.

[0072] The first implementation method, see Figure 1 , Figure 2 , Figure 4 , the method for data interaction between the simulation model and the control system model:

[0073] Using the deck platform, the simulation model is packaged into an fmu file, and the fmu file type that can interact with third-party software is selected. The generated fmu file can be deployed by third-party software and interact with other third-party software.

[0074] After the simulation model is packaged into an fmu file, it is placed in the NI simulator. The generated fmu file is deployed using third-party laboratory management software such as Veristand. After successful deployment, standard electrical signals are generated and input and output through NI hardware boards.

[0075] The control system based on the actual PLC uses I / O direct connection and hard wiring to connect with the NI hardware board to collect the standard electrical signals output by the NI hardware board. At the same time, various commands and parameters can be output to the simulation model by setting the values ​​of the input parameters on the human-machine interface of the control system host computer. In other words, the control system based on the actual PLC collects standard electrical signals and uses the NI simulation machine as an intermediate medium to interact with the simulation model.

[0076] The NI simulator runs on the Windows operating system, and the simulation model packaged as an fmu file runs on the NI simulator. At the same time, a third-party laboratory management software such as Veristand is used on the NI simulator to monitor the running status of the dynamic simulation model. For example, the control variable Model Command can be used on the Veristand workspace interface to control the start, pause and stop of the simulation model.

[0077] Based on the actual PLC control system, the human-machine interface runs on the upper workstation / PC. Through the human-machine interface on the upper computer, commands can be sent to control the simulation model and monitor various process parameters of the simulation model. The actual PLC collects standard electrical signals. Based on the control program written by the actual PLC, the hardware addresses of the input and output variables can be the same as the hardware addresses of the input and output variables in the control program of the control system under the real field signal environment, that is, to simulate the real field signal environment to the greatest extent.

[0078] The second implementation method, see Figure 5 , Figure 6, a method for data interaction between simulation model and control system model.

[0079] Using the deck platform, the simulation model is encapsulated into an fmu file that can be run under the Linux operating system, and the fmu file type that can interact with third-party software is selected. The fmu file generated in this way can be deployed by third-party software and interact with other third-party software for data.

[0080] After the simulation model is packaged into an fmu file that can run under the Linux operating system, the fmu file is deployed to the lower computer, the NI simulator (Linux system), using third-party laboratory management software such as veristand in the upper PC (Windows system). After successful deployment, standard electrical signals are generated and input and output through NI hardware boards. Compared with the Windows system, the Linux system has better real-time performance. Therefore, the simulation model runs in the NI simulator (Linux system), which has better real-time performance and faster and smoother data interaction between the simulation model and the control system.

[0081] The control system based on the actual PLC uses I / O direct connection and hard wiring to connect with the NI hardware board to collect the standard electrical signals output by the NI hardware board. At the same time, various commands and parameters can be output to the simulation model by setting the values ​​of the input parameters on the human-machine interface of the control system host computer. In other words, the control system based on the actual PLC collects standard electrical signals and uses the NI simulation machine as an intermediate medium to interact with the simulation model.

[0082] The NI simulator runs on the Linux operating system. The simulation model encapsulated as an fmu file is deployed to the NI simulator (Linux system) using a third-party laboratory management software such as Veristand on the host PC (Windows system) to run. At the same time, a third-party laboratory management software such as Veristand is used on the host PC (Windows system) to monitor the running status of the dynamic simulation model. For example, the control variable Model Command can be used on the workspace interface of Veristand to control the start, pause and stop of the simulation model.

[0083] Based on the actual PLC control system, the human-machine interface runs on another upper workstation / PC. Through the human-machine interface on another upper computer, commands can be sent to control the simulation model and monitor various process parameters of the simulation model. The actual PLC collects standard electrical signals. Based on the control program written by the actual PLC, the hardware addresses of the input and output variables can be the same as the hardware addresses of the input and output variables in the control program of the control system under the real field signal environment, that is, to simulate the real field signal environment to the greatest extent.

[0084] In the second implementation mode, the Linux operating system is run on the NI simulator, which has better real-time performance.

[0085] Beneficial effects of the present invention:

[0086] The present invention discloses a semi-hardware dynamic simulation platform for a cryogenic refrigeration system and a data interaction method thereof, including a simulation model of the cryogenic refrigeration system, a control system model of the cryogenic refrigeration system, and a method for data interaction between the simulation model and the control system model. The semi-hardware dynamic simulation platform for the cryogenic refrigeration system can understand the thermodynamic properties of the cryogenic refrigeration system in advance, simulate the dynamic heat load of the cryogenic refrigeration system, perform control program pre-verification, debug the main control logic of the cryogenic refrigeration system, and perform performance estimation under different working modes of the cryogenic refrigeration system. It provides a reference basis for the actual operation adjustment of the cryogenic refrigeration system and trains operators. The semi-hardware dynamic simulation platform adopts actual PLC hardware and can simulate the real on-site signal environment of the cryogenic refrigeration system to the greatest extent.

[0087] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0088] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0089] 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.

[0090] 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.

[0091] In addition, each functional unit in each embodiment of the present invention 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.

[0092] 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 invention, in essence, 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, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A semi-hardware dynamic simulation platform for a low-temperature refrigeration system, characterized in that: Including simulation model and control system model; among which: The simulation model is used to understand the thermodynamic performance of the cryogenic refrigeration system in advance, simulate the dynamic heat load of the cryogenic refrigeration system, and perform control program pre-verification; The control system model is the main body of the control logic; The semi-hardware dynamic simulation platform is used to debug the main control logic of the low-temperature refrigeration system and to perform performance estimation under different working modes of the low-temperature refrigeration system.

2. The semi-hardware dynamic simulation platform for low-temperature refrigeration system according to claim 1, characterized in that: The semi-hardware dynamic simulation platform is also used to provide a reference for the actual operation adjustment of the low-temperature refrigeration system and to train operators.

3. The semi-hardware dynamic simulation platform for low-temperature refrigeration system according to claim 1, characterized in that: When establishing a simulation model of a compressor station, the required component models are developed as needed; the compressor component model is customized, the performance characteristic curve of the compressor is written into the source code of the compressor component, and it is defined and packaged into a proprietary compressor model.

4. The semi-hardware dynamic simulation platform for low-temperature refrigeration system according to claim 1, characterized in that: When establishing a simulation model of a turbine expander unit, the required component models are developed as needed; the characteristic curve equation of each turbine is customized, and the characteristic curve equation of each turbine is written into the source code of the turbine component, and defined and packaged into a proprietary turbine model.

5. The semi-hardware dynamic simulation platform for low-temperature refrigeration system according to claim 1, characterized in that: When establishing a simulation model of a cold compressor unit, a cold compressor component model is developed as needed; during the simulation process, a computer-aided CFD method is used to calculate the spectrum curve of each cold compressor, and points are taken in the spectrum curve to specify the blockage line, pressure ratio vs. speed rp_vs_Nr, flow ratio vs. speed mr_vs_Nr, and efficiency vs. speed eta_vs_Nr parameters of each cold compressor. These parameters are used to modify the source code and encapsulate it into a custom cold compressor model.

6. The semi-hardware dynamic simulation platform for low-temperature refrigeration system according to claim 1, characterized in that: When establishing the simulation model of the low-temperature refrigeration system, the internal variables simulation time time and error information error are respectively encapsulated into usable 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.

7. The semi-hardware dynamic simulation platform for low-temperature refrigeration 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 needs to be established and the EL language code needs to be written in the experiment. Compile and run the experiment.

8. The semi-hardware dynamic simulation platform for low-temperature refrigeration system according to claim 7, characterized in that: Generate a deck platform based on ELexperiment code: 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.

9. A data interaction method using the semi-hardware dynamic simulation platform of the low-temperature refrigeration system of claim 1, characterized in that: include: Using the deck platform, encapsulate the simulation model into an fmu file and select the fmu file type that interacts with third-party software; After the simulation model is packaged into an fmu file, it is placed in the NI simulator. The generated fmu file is deployed using third-party laboratory management software. After successful deployment, a standard electrical signal is generated and input and output through the NI hardware board. Based on the actual PLC control system, the I / O is directly connected and hard-wired to the NI hardware board to collect the standard electrical signals output by the NI hardware board. At the same time, various commands and parameters are output to the simulation model by setting the values ​​of the input parameters on the human-machine interface of the control system host computer; The simulation model packaged into fmu file runs on the NI simulator, and the third-party laboratory management software is used on the NI simulator to monitor the running status of the dynamic simulation model; on the workspace interface of Veristand, the control variable Model Command is used to control the start, pause and stop of the simulation model; Based on the actual PLC control system, the human-machine interface runs on the upper workstation / PC. Through the human-machine interface on the upper computer, commands are sent to control the simulation model, and various process parameters of the simulation model are monitored at the same time; The actual PLC collects standard electrical signals. Based on the control program written based on the actual PLC, the hardware addresses of the input and output variables are the same as the hardware addresses of the input and output variables in the control program of the control system under the real field signal environment, simulating the real field signal environment to the greatest extent.

10. A data interaction method using the semi-hardware dynamic simulation platform of the low-temperature refrigeration system of claim 1, characterized in that: include: Using the deck platform, the simulation model is packaged into an fmu file that runs under the Linux operating system, and the fmu file type that interacts with third-party software is selected; After the simulation model is packaged into an fmu file running under the Linux operating system, the fmu file is deployed to the lower computer using a third-party laboratory management software in the upper PC. After successful deployment, a standard electrical signal is generated and input and output are performed through the NI hardware board. Based on the actual PLC control system, the I / O is directly connected and hard-wired to the NI hardware board to collect the standard electrical signals output by the NI hardware board. At the same time, various commands and parameters are output to the simulation model by setting the values ​​of the input parameters on the human-machine interface of the control system host computer; The simulation model packaged into fmu file is deployed to the NI simulator using third-party laboratory management software on the host PC. At the same time, the third-party laboratory management software is used on the host PC to monitor the running status of the dynamic simulation model. On the workspace interface of Veristand, the control variable Model Command is used to control the start, pause and stop of the simulation model. Based on the actual PLC control system, the human-machine interface runs on another upper workstation / PC. Through the human-machine interface on another upper computer, commands are sent to control the simulation model, and various process parameters of the simulation model are monitored at the same time; The actual PLC collects standard electrical signals. Based on the control program written based on the actual PLC, the hardware addresses of the input and output variables are the same as the hardware addresses of the input and output variables in the control program of the control system under the real field signal environment, simulating the real field signal environment to the greatest extent.

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