Semi-hardware dynamic simulation method and simulation platform for cold compressor unit

Abstract

The invention discloses a semi-hardware dynamic simulation method and simulation platform for a cold compressor unit, and is applied to the field of system simulation, and the method comprises the steps: building a simulation model of the cold compressor unit, compiling and operating the simulation model, and packaging the simulation model into an fmu file; based on an NI simulation machine, deploying the fmu file according to third-party software, and generating a standard electric signal; the standard electric signal is input and output through an NI hardware board card of the NI simulation machine; and acquiring the standard electric signal through a control system of an actual PLC, and performing data interaction with the simulation model.

Description

Technical Field

[0001] The invention relates to the field of system simulation, and in particular to a semi-hardware dynamic simulation method and a simulation platform for a cold compressor unit. Background Art

[0002] With the development of science and technology, large-scale cryogenic systems have been widely used in cutting-edge fields such as nuclear fusion, high-energy physics and superconducting systems. For large-scale superfluid helium cryogenic systems in the 2K temperature range, the current more common method is to use a multi-stage compression system to decompress the liquid helium container to obtain superfluid helium. Compared with the 4.5K cryogenic system, it is difficult for large-scale superfluid helium cryogenic systems to carry out the entire compression and evacuation process at room temperature in terms of the vacuum degree of the pumping system and the heat leakage of the system. Therefore, multi-stage centrifugal cold compressors are now mostly used for saturated helium vapor at low temperature and low pressure as a method of evacuation in the initial stage. Therefore, cold compressors play an important role in large-scale cryogenic systems and have become one of the most critical components in superfluid helium systems.

[0003] Large helium cryogenic systems at 2K have adopted cold compressors to decompress saturated liquid helium tanks at low temperature and low pressure to obtain superfluid helium or supercooled helium. At present, it is common to use three or four stages of cold compressors in series to vacuum extract saturated liquid helium tanks. For example, internationally, the 1.8K cryogenic system of the Large Hadron Collider (LHC) at CERN European Organization for Nuclear Research adopts a structure of three stages of cold compressors in series. The 500W@2K refrigerator developed by the Institute of Physics and Chemistry of the Chinese Academy of Sciences also adopts a structure of three stages of cold compressors in series. The 4000W@2K refrigerator being developed by the Institute of Physics and Chemistry of the Chinese Academy of Sciences is designed with a structure of four stages of cold compressors in series.

[0004] Under ultra-low temperature negative pressure conditions, the system has higher requirements for the stability of the cold compressor. Therefore, during the design process, in addition to ensuring the efficiency of the cold compressor, the stable operating range of the cold compressor should be appropriately widened to prevent the performance of the cold compressor from deteriorating due to changes in inlet parameters. Multi-stage cold compressor unit anti-surge control is required. For multi-stage series cold compressor units, the cold compressor of the latter stage needs to have a wider flow coverage range than the previous stage to ensure that the cold compressor unit can operate stably. During the planned use period of the actual operation of the cold compressor, the gas pressure, gas temperature, operating speed and flow rate are likely to change with other minor internal or external changes in the large cryogenic system. Therefore, it is particularly important to make an accurate variable operating performance estimate for the centrifugal cold compressor during the design stage.

[0005] The OTS (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 operated. Developing and utilizing the operation training system to train operators can avoid putting actual equipment in a dangerous situation. The operation training system can be operated 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.

[0006] In order to overcome these defects, the present application proposes a semi-hardware dynamic simulation method and simulation platform for a cold compression unit. Summary of the invention

[0007] The purpose of this application is to provide a semi-hardware dynamic simulation method and simulation platform for a refrigeration compressor unit, aiming to solve the above-mentioned problems.

[0008] To achieve the above objectives, this application provides the following technical solutions:

[0009] The present application provides a semi-hardware dynamic simulation method for a cold compression unit, comprising:

[0010] Establishing a simulation model of a cold compression unit, and compiling and running the simulation model to encapsulate it into an fmu file;

[0011] Based on the NI simulator, the fmu file is deployed according to third-party software to generate a standard electrical signal; the standard electrical signal is input and output through the NI hardware board of the NI simulator;

[0012] The standard electrical signal is acquired through the actual PLC control system to perform data interaction with the simulation model.

[0013] Furthermore, in establishing the simulation model of the cold compression unit, the steps of compiling and running the simulation model and encapsulating it into an fmu file specifically include the following steps:

[0014] Compiling the simulation model, generating components, and verifying the components;

[0015] Establish a simulation environment based on the components, write EL language code in the simulation environment, and control the running state of the simulation model;

[0016] A deck platform is generated by using the simulation environment and the EL language code, and the simulation model is packaged into an fmu file based on the deck platform.

[0017] Furthermore, in the deck platform, input variables and output variables are defined;

[0018] The input variables are variables controlled by the third-party software, including but not limited to: the opening of each regulating valve, the opening of each switch valve, the power of each electric heater, each boundary condition, and each PID automatic signal;

[0019] The output variables are process values ​​calculated by the simulation model, including but not limited to: temperatures before and after each stage of heat exchangers, pressures before and after each stage of heat exchangers, and flow rates before and after each stage of heat exchangers, openings of each valve, inlet and outlet temperatures of each valve, inlet and outlet pressures of each valve, and inlet and outlet flow rates of each valve, inlet and outlet temperatures of each stage of cold compressors, inlet and outlet pressures of each stage of cold compressors, and inlet and outlet flow rates of each stage of cold compressors, pressure ratios of each stage of cold compressors, speeds of each stage of cold compressors, and efficiencies of each stage of cold compressors, temperatures of each gas-liquid separator, pressures of each gas-liquid separator, liquid levels of each gas-liquid separator, inlet and outlet flow rates of each gas-liquid separator, and power of each gas-liquid separator electric heater.

[0020] Further, based on the NI simulator, the fmu file is deployed according to the third-party software to generate a standard electrical signal; the standard electrical signal is input and output through the NI hardware board of the NI simulator, specifically including the following steps:

[0021] After the simulation model is packaged as an fmu file, it is placed in the NI simulation machine, and a third-party software is selected to deploy the fmu file;

[0022] The third-party software controls the start, pause and end of the simulation model;

[0023] The standard electrical signals include but are not limited to: 0-20mA current signal, 4-20mA current signal, 0-10V voltage signal, -10V-+10V voltage signal, 0-5V voltage signal, 1-5V voltage signal.

[0024] Furthermore, in the step of acquiring the standard electrical signal through the actual PLC control system and performing data interaction with the simulation model, the following steps are specifically included:

[0025] The control system based on the actual PLC obtains the standard electrical signal, and uses the NI simulator as a medium to perform data interaction with the simulation model;

[0026] Based on the control program of the control system, the hardware addresses of the input variables and output variables of the PLC are the same as the hardware addresses of the input variables and output variables in the control program of the control system under the real field signal environment; wherein the input variables of the PLC are the output variables of the simulation model, and the output variables of the PLC are the input variables of the simulation model.

[0027] Further, setting the value of the input parameter on the human-machine interface of the control system of the actual PLC, and outputting commands and parameters to the simulation model;

[0028] The human-machine interface of the control system is used to send commands and perform monitoring.

[0029] The present application provides a semi-hardware dynamic simulation platform for a refrigeration compressor unit, comprising:

[0030] Model building module: building a simulation model of the cold compressor unit, and packaging the simulation model into an fmu file by compiling and running the simulation model;

[0031] Output module: Based on the NI simulator, the fmu file is deployed according to third-party software to generate a standard electrical signal; the standard electrical signal is input and output through the NI hardware board of the NI simulator;

[0032] Data interaction module: obtains the standard electrical signal through the actual PLC control system and performs data interaction with the simulation model.

[0033] Further, the control system includes a control program and a human-machine interface;

[0034] The actual PLC is connected to the NI simulation machine via the NI hardware board.

[0035] The present application provides a device, which includes a processor and a memory coupled to the processor, wherein the memory stores program instructions for implementing a semi-hardware dynamic simulation method for a cold compression unit; the processor is used to execute the program instructions stored in the memory to implement a semi-hardware dynamic simulation of a cold compression unit.

[0036] The present application provides a storage medium storing program instructions executable by a processor, wherein the program instructions are used to execute a semi-hardware dynamic simulation method for a cold compression unit.

[0037] The present application provides a semi-hardware dynamic simulation method and simulation platform for a cold compressor unit, which has the following beneficial effects:

[0038] (1) Through the simulation platform, the operating conditions of the cold compressor unit can be simulated in advance, and its working characteristics can be deeply understood, including the changes in parameters such as pressure, flow, and temperature under different working conditions, so as to make full preparations before actual application;

[0039] (2) Through dynamic simulation, the performance of the cold compressor unit under different working conditions is estimated, including the relationship between pressure ratio and flow rate at different speeds, so as to determine the safe operating range and performance boundary of the cold compressor, which is of great significance for ensuring the long-term stable operation of the system;

[0040] (3) The simulation platform of this application can be used as an operation training system (OTS) to provide simulation operation training for operators. By simulating actual working conditions and operation interfaces, operators can learn system operation and maintenance knowledge in a risk-free environment, thereby improving their skills and work efficiency.

[0041] (4) Using actual PLC hardware and NI boards for hard-wired I / O direct connection can simulate the real signal environment of the refrigeration compressor unit to the greatest extent, which makes the simulation results closer to reality and improves the accuracy and reliability of the simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic flow chart of a semi-hardware dynamic simulation method for a cold compression unit according to Embodiment 1 of the present application;

[0043] Figure 2 This is a schematic diagram of the process flow of three series-connected cold compression units in Example 1 of the present application;

[0044] Figure 3 This is a schematic diagram of the process flow of four series-connected cold compression units in Example 1 of the present application;

[0045] Figure 4 This is a technical architecture diagram of a semi-hardware dynamic simulation platform (Windows system) of a cold compression unit in Example 1 of the present application;

[0046] Figure 5 This is a technical architecture diagram of a semi-hardware dynamic simulation platform (Linux system) of a cold compression unit in Example 1 of the present application;

[0047] Figure 6 This is a structural schematic diagram of a semi-hardware dynamic simulation platform for a cold compression unit according to Example 2 of the present application;

[0048] Figure 7 This is a flowchart of a semi-hardware dynamic simulation platform for a cold compression unit according to Embodiment 2 of the present application;

[0049] Figure 8 This is a schematic diagram of the device structure of Example 3 of the present application;

[0050] Fig. 9 This is a schematic diagram of the storage medium structure of Example 4 of the present application. DETAILED DESCRIPTION

[0051] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions 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 making creative work are within the scope of protection of this application.

[0053] Example 1

[0054] See also Figure 1 , is a flow chart of a semi-hardware dynamic simulation method of a cold compression unit in Example 1 of the present application; the steps include:

[0055] S1: Establish a simulation model of the cold compression unit, compile and run the simulation model, and encapsulate it into an fmu file.

[0056] In this embodiment, when establishing the simulation model of the cold compressor group, the cold compressor component model is developed as needed. In the simulation process, the computer-aided CFD method is used to calculate the spectrum curve of each cold compressor respectively, and points are 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 respectively; these parameters are 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.

[0057] When establishing the simulation model of the cold compressor unit, internal variables are introduced into the simulation model, wherein the internal variables include simulation time and error information. The simulation time is encapsulated as a simulation time component, the simulation time component output is a simulation time value, and the output is set to a real value of the analog type; the error information is encapsulated as an error information component, the error information component output is an error information value, and the output is set to a real value of the analog type.

[0058] Compile the simulation model: the simulation time component and the error information component do not need to be connected to the main loop of the simulation model. Just place the packaged simulation time component and the error information component and the main loop model of the simulation model in the same screen, and the model can run smoothly after compilation.

[0059] After the simulation model is compiled, a component (partition) is generated and the component (partition) is verified (validated). After the component is verified, a simulation environment (experiment) is established and the EL language code is written in the simulation environment (experiment).

[0060] Through the simulation environment (experiment) and EL language code, the deck platform is generated based on the EL experiment code.

[0061] In the deck platform, input variables and output variables are defined; input variables are variables controlled by the third-party software, including but not limited to: the opening of each regulating valve, the opening of each switch valve, the power of each electric heater, each boundary condition, and each PID automatic signal.

[0062] The output variables are process values ​​calculated by the simulation model, including but not limited to: temperatures before and after each stage of heat exchangers, pressures before and after each stage of heat exchangers, and flow rates before and after each stage of heat exchangers, openings of each valve, inlet and outlet temperatures of each valve, inlet and outlet pressures of each valve, and inlet and outlet flow rates of each valve, inlet and outlet temperatures of each stage of cold compressors, inlet and outlet pressures of each stage of cold compressors, and inlet and outlet flow rates of each stage of cold compressors, pressure ratios of each stage of cold compressors, speeds of each stage of cold compressors, and efficiencies of each stage of cold compressors, temperatures of each gas-liquid separator, pressures of each gas-liquid separator, liquid levels of each gas-liquid separator, inlet and outlet flow rates of each gas-liquid separator, and power of each gas-liquid separator electric heater.

[0063] See also Figure 2 , is a schematic diagram of the process of three series-connected cold compressor units of Example 1 of the present application. The cold compressor unit consists of three series-connected cold compressors CC1, CC2, CC3, a 2K liquid helium tank D4500, a throttle valve CV1, a negative pressure heat exchanger HEX1, a heat exchanger HEX2, and a HEX3.

[0064] The working process is as follows:

[0065] (1) Liquid helium from the 4K part of the refrigerator first enters the negative pressure heat exchanger HEX1 for further cooling, and is throttled into gas and liquid phases by the throttle valve CV1. The liquid phase accumulates in the 2K liquid helium tank, and the gas phase returns to the negative pressure circuit through the return gas pipeline.

[0066] (2) When the liquid level in the 2K liquid helium tank D4500 reaches a certain height, the cold compressor units CC1, CC2, and CC3 are started to reduce the pressure and temperature of D4500 to about 3000Pa, reaching the 2K superfluid helium temperature.

[0067] (3) The saturated gas heated by the electric heater in the superfluid helium dewar D4500 flows back through the negative pressure circuit, and after being compressed in sequence by the three-stage series cold compressor unit, it enters the negative pressure circuits of the heat exchangers HEX2 and HEX3 in turn, exchanges heat with the room temperature helium coming from the room temperature high pressure main circuit, and then goes to the room temperature pump unit or the suction port of the negative pressure compressor to complete the whole cycle.

[0068] (4) The cold compressor unit is composed of three cold compressors connected in series. When simulating the system, the cold compressor model can be customized first, the source code can be modified according to the designed cold compressor working range, and then packaged into a customized cold compressor model, and then the cold compressor unit simulation model can be built.

[0069] (5) Adjust various parameters of the custom cold compressor model and simulate the cold compressor unit under different parameters.

[0070] (6) Set the boundary conditions of high-pressure inflow and negative-pressure return flow to perform dynamic simulation of the cold compression unit.

[0071] Figure 2 The input variables are: opening of regulating valve CV1, power of electric heater in 2K liquid helium tank D4500, automatic PID start of liquid level in 2K liquid helium tank D4500, automatic PID start of flow of cold compressor CC1-CC3, automatic PID start of speed of cold compressor CC1-CC3, temperature, pressure and flow rate of inflow from room temperature and high pressure main road (two out of three), temperature, pressure and flow rate of outflow to low temperature and high pressure main road (two out of three), temperature, pressure and flow rate of inflow from 4K liquid helium (two out of three), temperature, pressure and flow rate of outflow to room temperature pump group or suction port of negative pressure compressor (two out of three).

[0072] Output variables are: simulation time time, error message error (optional, if the system has it). Opening of control valve CV1, inlet and outlet temperature of control valve CV1, inlet and outlet pressure of control valve CV1, inlet and outlet flow of control valve CV1, temperature before and after heat exchanger HEX1-HEX3, pressure before and after heat exchanger HEX1-HEX3, flow before and after heat exchanger HEX1-HEX3, power of electric heater in 2K liquid helium tank D4500, temperature of 2K liquid helium tank D4500, pressure of 2K liquid helium tank D4500, liquid level of 2K liquid helium tank D4500, inlet and outlet flow of 2K liquid helium tank D4500. Inlet and outlet temperature of cold compressor CC1-CC3, inlet and outlet pressure of cold compressor CC1-CC3, inlet and outlet flow of cold compressor CC1-CC3, pressure ratio of cold compressor CC1-CC3, speed of cold compressor CC1-CC3, efficiency of cold compressor CC1-CC3, etc.

[0073] See also Figure 3 , which is a flow diagram of four series-connected cold compressor units in Example 1 of the present application. The cold compressor unit consists of four series-connected cold compressors CC1, CC2, CC3, CC4, a 2K liquid helium tank D4500, a throttle valve CV1, a negative pressure heat exchanger HEX1, a cold compressor unit inlet switch valve XV1, a cold compressor unit outlet regulating valve CV3, and a cold compressor unit bypass valve CV2.

[0074] The working process is as follows:

[0075] (1) The 4.5K@3bara supercooled supercritical helium from the refrigerator enters the negative pressure heat exchanger HEX1, and is throttled into gas and liquid phases by the throttle valve CV1. The liquid phase accumulates in the 2K gas-liquid separator D4500, and the gas phase returns from the top of D4500, passes through the heat exchanger HEX1 in reverse flow, and enters the cold compressor unit. When the liquid helium level in D4500 does not reach a certain value, the return helium returns from the cold compressor unit bypass regulating valve CV2;

[0076] (2) When the liquid helium level in D4500 reaches a certain value, the cold compressor unit starts to decompress the helium in D4500 to the superfluid helium saturation pressure of 0.03 bar, thereby forming 2K saturated superfluid helium in D4500. The top return gas of D4500 flows back through the negative pressure heat exchanger HEX1 and enters the cold compressor unit.

[0077] (3) The cold compressor unit increases the helium pressure in the downstream pipeline from 0.03 bar to 0.5 bar. The 0.5 bar negative pressure helium goes to the negative pressure line and is compressed by the negative pressure compressor, completing the entire cycle.

[0078] (4) When the cold compressor unit is not started, the return air is returned from the bypass valve CV2. After the cold compressor unit is started, the bypass valve CV2 is slowly closed.

[0079] (5) The cold compressor unit is composed of four cold compressors connected in series. When simulating the system, the cold compressor model can be customized first, the source code can be modified according to the designed cold compressor working range, and then packaged into a customized cold compressor model, and then the cold compressor unit simulation model can be built.

[0080] (6) Adjust various parameters of the custom cold compressor model and simulate the cold compressor unit under different parameters.

[0081] (7) Set the boundary conditions of supercooled supercritical helium inflow and negative pressure reflux, and perform dynamic simulation of the cold compression unit.

[0082] Figure 3 The input variables are: the opening of the regulating valves CV1-CV3, the opening of the switch valve XV1, the power of the electric heater in the 2K liquid helium tank D4500, the liquid level PID in the 2K liquid helium tank D4500, the flow PID of the cold compressor CC1-CC4, the speed PID of the cold compressor CC1-CC4, the temperature, pressure and flow of the inflow from the supercooled supercritical helium (two out of the three), and the temperature, pressure and flow of the outflow to the negative pressure line (two out of the three).

[0083] Output variables are: simulation time time, error message error (optional, if the system has it). Opening of regulating valves CV1-CV3, inlet and outlet temperatures of regulating valves CV1-CV3, inlet and outlet pressures of regulating valves CV1-CV3, inlet and outlet flows of regulating valves CV1-CV3, opening of switch valve XV1, inlet and outlet temperatures of switch valve XV1, inlet and outlet pressures of switch valve XV1, inlet and outlet flows of switch valve XV1, temperatures before and after heat exchanger HEX1, pressures before and after heat exchanger HEX1, flows before and after heat exchanger HEX1, power of electric heater in 2K liquid helium tank D4500, temperature of 2K liquid helium tank D4500, pressure of 2K liquid helium tank D4500, liquid level of 2K liquid helium tank D4500, inlet and outlet flows of 2K liquid helium tank D4500. Inlet and outlet temperatures of cold compressors CC1-CC4, inlet and outlet pressures of cold compressors CC1-CC4, inlet and outlet flows of cold compressors CC1-CC4, pressure ratio of cold compressors CC1-CC4, speed of cold compressors CC1-CC4, efficiency of cold compressors CC1-CC4, etc.

[0084] It can be understood that the cold compressor units applicable to the present application include but are not limited to 1 cold compressor, 2 cold compressors connected in series, 3 cold compressors connected in series, 4 cold compressors connected in series, or even more cold compressors connected in series, etc. At the same time, the cold compressor needs to work in a certain working range, that is, the stable area where the cold compressor can work normally is between the surge line and the blockage line of the cold compressor.

[0085] S2: Based on the NI simulator, the fmu file is deployed according to third-party software to generate a standard electrical signal; the standard electrical signal is input and output through the NI hardware board of the NI simulator.

[0086] In this embodiment, the deck platform is used to encapsulate the simulation model into a file running under the Windows operating system or the Linux operating system.

[0087] See also Figure 4 , which is a technical architecture diagram of a semi-hardware dynamic simulation platform (Windows system) of a cold compressor unit in Example 1 of the present application. Using the deck platform, the simulation model is encapsulated into an fmu file, and an 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.

[0088] 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.

[0089] 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.

[0090] When the NI simulator runs on Windows, the simulation model packaged as an fmu file runs on the NI simulator, and 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.

[0091] The standard electrical signal refers to the standard electrical signal commonly used in the industrial control field, including but not limited to 0~20mA current signal, 4~20mA current signal, 0~10V voltage signal, -10V~+10V voltage signal, 0~5V voltage signal, and 1~5V voltage signal.

[0092] See also Figure 5 , which is a technical architecture diagram of a semi-hardware dynamic simulation platform (Linux system) of a cold compression unit in Example 1 of the present application.

[0093] 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. After the simulation model is encapsulated into an fmu file that can be run under the Linux operating system, in the upper PC (windows system), the fmu file is deployed to the lower computer, namely the NI simulator (Linux system) using third-party laboratory management software such as veristand. After successful deployment, a standard electrical signal is generated and input and output through the NI hardware board. Compared with the windows system, the Linux system has better real-time performance. Therefore, the simulation model runs in the NI simulator (Linux system), and the real-time performance is better. The data interaction between the simulation model and the control system is faster and smoother. The control system based on the actual PLC adopts I / O direct connection and hard wiring to connect 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 can be output to the simulation model by setting the value of the input parameter 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.

[0094] 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.

[0095] S3: Acquire the standard electrical signal through the actual PLC control system and perform data interaction with the simulation model.

[0096] In this embodiment, the control system based on the actual PLC acquires the standard electrical signal and uses the NI simulation machine as a medium to perform data exchange with the simulation model.

[0097] Based on the control program of the control system, the hardware addresses of the input variables and output variables of the PLC are the same as the hardware addresses of the control program of the control system under the real field signal environment; wherein the input variables of the PLC are the output variables of the simulation model, and the output variables of the PLC are the input variables of the simulation model.

[0098] The values ​​of the input parameters are set on the human-machine interface of the control system of the actual PLC, and commands and parameters are output to the simulation model; wherein the human-machine interface of the control system is used to send commands and perform monitoring.

[0099] In summary, Example 1 of the present application can understand the working characteristics of the cold compressor unit in advance, pre-verify the control system, debug the main control logic of the cold compressor unit, and estimate the variable working condition performance of the cold compressor unit through the simulation method of the present application. Obtain the performance curve of the relationship between the pressure ratio and flow rate of the cold compressor at different speeds, determine the safe operating range of the cold compressor, prevent the cold compressor from entering surge and blockage conditions, provide a reference basis for the actual operation adjustment of the cold compressor unit, and train operators. At the same time, the use of actual PLC hardware can simulate the real signal environment of the cold compressor unit to the greatest extent.

[0100] Example 2

[0101] See also Figure 6 , is a structural schematic diagram of a semi-hardware dynamic simulation platform for a cold compression unit in Example 2 of the present application; the specific contents include:

[0102] Model building module: building a simulation model of the cold compressor unit, and packaging the simulation model into an fmu file by compiling and running the simulation model;

[0103] Output module: Based on the NI simulator, the fmu file is deployed according to third-party software to generate a standard electrical signal; the standard electrical signal is input and output through the NI hardware board of the NI simulator;

[0104] Data interaction module: obtains the standard electrical signal through the actual PLC control system and performs data interaction with the simulation model.

[0105] Example 3

[0106] See also Figure 8 , is a schematic diagram of the device structure of Embodiment 3 of the present application. The device 50 includes a processor 51 and a memory 52 coupled to the processor 51 .

[0107] The memory 52 stores program instructions for implementing the above-mentioned semi-hardware dynamic simulation method of a cold compression unit.

[0108] The processor 51 is used to execute program instructions stored in the memory 52 to implement a semi-hardware dynamic simulation of a cold compression unit.

[0109] The processor 51 may also be referred to as a CPU (Central Processing Unit).

[0110] The processor 51 may be an integrated circuit chip with signal processing capabilities. The processor 51 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0111] Example 4

[0112] See also Fig. 9 , which is a schematic diagram of the structure of the storage medium of Example 4 of the present application. The storage medium of the embodiment of the present application stores a program file 61 that can implement all the above methods, wherein the program file 61 can be stored in the above storage medium in the form of a software product, including a number of instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or a computer, a server, a mobile phone, a tablet, and other devices.

[0113] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0114] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

[0115] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

[0116] Of course, the present invention may have many other implementations. Based on this implementation, other implementations obtained by ordinary technicians in this field without any creative work are all within the scope of protection of the present invention.

Claims

1. A semi-hardware dynamic simulation method for a cold compression unit, characterized in that: include: Establishing a simulation model of a cold compression unit, and compiling and running the simulation model to encapsulate it into an fmu file; Based on the NI simulator, the fmu file is deployed according to third-party software to generate a standard electrical signal; The standard electrical signal is input and output through the NI hardware board of the NI simulator; The standard electrical signal is acquired through the actual PLC control system to perform data interaction with the simulation model.

2. A semi-hardware dynamic simulation method for a cold compression unit according to claim 1, characterized in that: In establishing the simulation model of the cold compressor unit, the steps of compiling and running the simulation model and packaging it into an fmu file specifically include the following steps: Compiling the simulation model, generating components, and verifying the components; Establish a simulation environment based on the components, write EL language code in the simulation environment, and control the running state of the simulation model; A deck platform is generated by using the simulation environment and the EL language code, and the simulation model is packaged into an fmu file based on the deck platform.

3. A semi-hardware dynamic simulation method for a cold compression unit according to claim 2, characterized in that: In the deck platform, input variables and output variables are defined; The input variables are variables controlled by the third-party software, including but not limited to: the opening of each regulating valve, the opening of each switch valve, the power of each electric heater, each boundary condition, and each PID automatic signal; The output variables are process values ​​calculated by the simulation model, including but not limited to: temperatures before and after each stage of heat exchangers, pressures before and after each stage of heat exchangers, and flow rates before and after each stage of heat exchangers, openings of each valve, inlet and outlet temperatures of each valve, inlet and outlet pressures of each valve, and inlet and outlet flow rates of each valve, inlet and outlet temperatures of each stage of cold compressors, inlet and outlet pressures of each stage of cold compressors, and inlet and outlet flow rates of each stage of cold compressors, pressure ratios of each stage of cold compressors, speeds of each stage of cold compressors, and efficiencies of each stage of cold compressors, temperatures of each gas-liquid separator, pressures of each gas-liquid separator, liquid levels of each gas-liquid separator, inlet and outlet flow rates of each gas-liquid separator, and power of each gas-liquid separator electric heater.

4. The semi-hardware dynamic simulation method of a cold compression unit according to claim 1, characterized in that: In the step of deploying the fmu file based on a NI simulator according to third-party software to generate a standard electrical signal; and inputting and outputting the standard electrical signal through a NI hardware board of the NI simulator, the following steps are specifically included: After the simulation model is packaged as an fmu file, it is placed in the NI simulation machine, and a third-party software is selected to deploy the fmu file; The third-party software controls the start, pause and end of the simulation model; The standard electrical signals include but are not limited to: 0-20mA current signal, 4-20mA current signal, 0-10V voltage signal, -10V-+10V voltage signal, 0-5V voltage signal, 1-5V voltage signal.

5. The semi-hardware dynamic simulation method of a cold compression unit according to claim 1, characterized in that: The step of acquiring the standard electrical signal through the actual PLC control system and performing data interaction with the simulation model specifically includes the following steps: The control system based on the actual PLC obtains the standard electrical signal, and uses the NI simulator as a medium to perform data interaction with the simulation model; Based on the control program of the control system, the hardware addresses of the input variables and output variables of the PLC are the same as the hardware addresses of the input variables and output variables in the control program of the control system under the real field signal environment; wherein the input variables of the PLC are the output variables of the simulation model, and the output variables of the PLC are the input variables of the simulation model.

6. The semi-hardware dynamic simulation method of a cold compression unit according to claim 1, characterized in that: Setting the values ​​of input parameters on the human-machine interface of the control system of the actual PLC, and outputting commands and parameters to the simulation model; The human-machine interface of the control system is used to send commands and perform monitoring.

7. A simulation platform for a semi-hardware dynamic simulation method of a cold compression unit according to any one of claims 1 to 6, characterized in that: include: Model building module: building a simulation model of the cold compressor unit, and packaging the simulation model into an fmu file by compiling and running the simulation model; Output module: Based on the NI simulator, the fmu file is deployed according to third-party software to generate a standard electrical signal; The standard electrical signal is input and output through the NI hardware board of the NI simulator; Data interaction module: obtains the standard electrical signal through the actual PLC control system and performs data interaction with the simulation model.

8. A semi-hardware dynamic simulation platform for a cold compression unit according to claim 7, characterized in that: The control system includes a control program and a human-machine interface; The actual PLC is connected to the NI simulation machine via the NI hardware board.

9. A device, characterized in that: The device includes a processor and a memory coupled to the processor, wherein the memory stores program instructions for implementing a semi-hardware dynamic simulation method for a cold compressor unit as described in any one of claims 1-6; and the processor is used to execute the program instructions stored in the memory to implement a semi-hardware dynamic simulation of a cold compressor unit.

10. A storage medium, characterized in that: The device stores program instructions executable by a processor, wherein the program instructions are used to execute a semi-hardware dynamic simulation method for a cold compression unit as described in any one of claims 1 to 6.

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