CN107272442B - Real-time simulation platform for large helium cryogenic system - Google Patents

Abstract

The invention discloses a real-time simulation platform of a large helium cryogenic system, which is characterized in that a compressor model, a cold box model and a load model are established in software, and a sequential method is adopted to integrate the compressor model, the cold box model and the load model into a cryogenic system model. And establishing a control model based on an EPICS framework, and realizing real-time communication between the low-temperature model and the control system model based on an OPC communication protocol. Compared with other low-temperature system simulation platforms, the system has better integration, and particularly aims at the characteristics of typical nonlinearity, time variation, multivariable coupling characteristic, complex system operation mode and the like of a large helium low-temperature system.

Description

A real-time simulation platform for a large-scale helium cryogenic system

technical field

The invention relates to the field of low-temperature system simulation platforms, in particular to a large-scale helium low-temperature system real-time simulation platform.

Background technique

The large-scale helium cryogenic system is one of the indispensable and important subsystems of the large-scale scientific experimental device with superconducting equipment. It provides a stable and reliable low-temperature operating environment for the experimental device. The efficiency and stability of the system are related to the energy consumption of the entire large-scale scientific device. and operating status. Large-scale low-temperature systems have large energy consumption, low efficiency, and complex operation modes.

Due to the multi-variable and strong coupling of large-scale cryogenic systems, the control systems involved in dynamic operation are very complex, and it is difficult to perform stable analysis in order to intuitively optimize the process. It can be helpful to solve this problem by conducting research on large-scale low temperature system simulation technology. Dynamic simulation research builds a virtual process on the computer by means of system modeling, and uses the component model to replace the actual equipment, thereby reproducing the operating state of the equipment. This can not only improve people's overall awareness of the system, but also eliminate the need for actual operation of equipment, reducing unnecessary waste of energy, manpower and material resources. With the rapid development of simulation technology in industry, researchers gradually apply process simulation technology to large and medium-sized helium cryogenic systems. Dynamic simulation technology can be widely used in large-scale cryogenic systems, aiming to improve the understanding of the dynamic characteristics of the actual system, the dynamic process optimization design of the process, the verification of new control methods and strategies, the safety protection and fault diagnosis prediction, the system virtual process debugging and the operator training, etc.

For the simulation of the helium cryogenic system of large scientific installations, it has developed from the simulation of a single cryogenic system to the simulation of large refrigerators and the entire equipment with load users, mainly focusing on the research on the temperature field, pressure field and control strategy of the entire system . There are still some key problems to be solved in the current dynamic simulation. First, the international chemical simulation software Hysys and Ecosimpro contain unit modules that can be applied to large-scale low-temperature systems. However, the simulation accuracy and model settings of general-purpose software cannot be fully satisfied. Actual cryogenic system simulation needs. In addition, the dynamic simulation of large-scale cryogenic systems focuses on the process model and the realization of part of the control loop, lacking a control system simulation platform.

SUMMARY OF THE INVENTION The purpose of the present invention is to provide a real-time simulation platform for a large-scale helium cryogenic system, so as to solve the problem that process simulation and control system simulation cannot be integrated in the simulation of large-scale helium cryogenic system in the prior art, and data synchronization exists in the real-time simulation process. defect problem.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A real-time simulation platform for a large-scale helium cryogenic system, characterized in that it includes a helium cryogenic system model established in Ecosimpro software according to mechanism modeling and system identification methods, and the helium cryogenic system model includes a compressor model, a cold box model and a load Model; compressor model, cold box model and load model are connected to form a low temperature process model based on sequential method; a measurement sensor model based on mechanism modeling is also established in Ecosimpro software, and the measurement sensor model is added to the low temperature process model;

It also includes a control system model based on the EPICS architecture. The control system model includes a PID control module, an analog signal module, and a digital signal module, wherein the PID control loop uses IOC as a virtual controller to process data and implement control logic;

An OPC server is established in the Ecosimpro software, and an OPC client is established in the IOC virtual controller. Real-time communication between the low-temperature process model and the control system model is realized based on the OPC communication protocol.

In the control system model, the analog signal module is connected with the PID control module to realize the control loop control. The analog signal module and the digital signal module communicate with the low temperature process model through the OPC client based on the OPC communication protocol.

The real-time simulation platform for a large-scale helium cryogenic system is characterized in that the compressor models include but are not limited to screw compressors, medium-pressure helium storage tank models, high-pressure and low-pressure pipeline models, and pneumatic control valve models.

The real-time simulation platform for a large-scale helium cryogenic system is characterized in that: the cold box model includes but is not limited to a turboexpander model, a multi-flow heat exchanger, an adsorber, a pipeline and a pneumatic adjustment model.

The real-time simulation platform of a large-scale helium cryogenic system is characterized in that: the load model includes but is not limited to a phase separator, a cold press and a regulating valve model.

The real-time simulation platform for a large-scale helium cryogenic system is characterized in that: the measurement sensor model includes but is not limited to a pressure sensor, a temperature sensor, a flow sensor and a liquid level sensor.

The described real-time simulation platform for a large-scale helium cryogenic system is characterized in that: according to the process flow and design parameters of the existing helium cryogenic system, the basic design parameters of the compressor model, the cold box model and the load model are respectively input in the Ecosimpro software, In Ecosimpro software, a helium cryogenic system model is established based on basic design parameters and based on mechanism modeling and system identification methods.

The described real-time simulation platform of a large-scale helium cryogenic system is characterized in that: the principle of connecting the compressor model, the cold box model and the load model based on the sequential method is:

(1) The two storage devices are connected by thermal components;

(2) A storage device and a thermal power device are connected through a series of thermal components.

The described real-time simulation platform of a large-scale helium cryogenic system is characterized in that: a PC is used as a system model server for storing a low-temperature process model and a measurement sensor model, and another PC is used as a workstation for storing the control system model, The open source software CSS is also used in the workstation as the monitoring software of the upper computer. The IOC virtual controller and the monitoring software of the upper computer are connected through the Profibus bus. The monitoring software of the upper computer is equipped with control logic algorithm, database and monitoring interface, and the system model server and workstation Physically realize real-time communication based on OPC communication protocol through Ethernet.

The present invention provides an open real-time simulation platform for large-scale helium cryogenic system based on EPICS. The control system host computer software adopts open source software CSS to develop monitoring interface, and OPC communication protocol is used as the protocol for communication between simulation model data and control system to realize process model and control. The real-time communication of the system simplifies the simulation structure of the large-scale helium cryogenic system and facilitates the integration of the entire simulation system.

Compared with other low-temperature system simulation platforms, the present invention has better integration, especially for the typical nonlinear, time-varying, multi-variable coupling characteristics of large-scale helium low-temperature systems, complex system operation modes, etc. The traditional low-temperature simulation system Mainly based on numerical simulation and process simulation, it is isolated from the control system and cannot truly simulate the dynamic characteristics and control algorithms of low-temperature systems. The invention adopts an open control structure to realize the integration of process and control simulation, and simulates the dynamic characteristics of the actual low-temperature system based on component modeling. Based on this platform, the stability and reliability of the entire system can be highly simulated, while satisfying operator training and virtual operational requirements.

Description of drawings

FIG. 1 is an overall block diagram of the system of the present invention.

Figure 2 is the OPC server development structure diagram.

Detailed ways

As shown in Figure 1, a real-time simulation platform of a large-scale helium cryogenic system includes a helium cryogenic system model established in Ecosimpro software according to mechanism modeling and system identification methods, and the helium cryogenic system model includes a compressor model and a cold box model. and load model; compressor model, cold box model and load model are connected to form a low temperature process model based on sequential method; a measurement sensor model based on mechanism modeling is also established in Ecosimpro software, and the measurement sensor model is added to the low temperature process model ;

It also includes a control system model based on the EPICS architecture. The control system model includes a PID control module, an analog signal module, and a digital signal module, wherein the PID control loop uses IOC as a virtual controller to process data and implement control logic;

In the present invention, the analog signal module needs to be connected with the PID control module. The analog signal module and the digital signal module communicate with the low temperature model through the OPC client based on the OPC communication protocol.

In the present invention, PID is a control module, IOC is a virtual controller, and the virtual controller handles all control loops and data input and output. The PID control module is only used in the PID control loop.

An OPC server is established in the Ecosimpro software, and an OPC client is established in the IOC virtual controller. Real-time communication between the low-temperature process model and the control system model is realized based on the OPC communication protocol.

In the control system model, the analog signal module is connected with the PID control module to realize the control loop control. The analog signal module and the digital signal module communicate with the low temperature process model through the OPC client based on the OPC communication protocol.

Compressor models include, but are not limited to, screw compressors, medium-pressure helium storage tanks, high- and low-pressure pipeline models, and pneumatic control valve models.

Cold box models include, but are not limited to, turboexpander models, multi-flow heat exchangers, adsorbers, piping, and pneumatic regulation models.

Load models include, but are not limited to, phase separators, cold presses, and regulating valve models. Measurement sensor models include, but are not limited to, pressure sensors, temperature sensors, flow sensors, and level sensors.

According to the process and design parameters of the existing helium cryogenic system, the basic design parameters of the compressor model, the cold box model and the load model are input into the Ecosimpro software respectively, and the Ecosimpro software is established according to the basic design parameters and based on the mechanism modeling and system identification methods. Helium cryogenic system model.

The principle of connecting the compressor model, the cold box model and the load model based on the sequential method is:

(1) The two storage devices are connected by thermal components;

(2) A storage device and a thermal power device are connected through a series of thermal components.

One PC is used as the system model server for storing the low-temperature process model and measurement sensor model, and another PC is used as the workstation for storing the control system model. In the workstation, the open source software CSS is used as the upper computer monitoring software and the IOC virtual controller. It is connected with the monitoring software of the upper computer through the Profibus bus. The monitoring software of the upper computer is equipped with control logic algorithm, database and monitoring interface, and the real-time communication based on the OPC communication protocol is realized physically between the system model server and the workstation through Ethernet.

Figure 2 shows the development structure of the OPC server. First, a low temperature model is established in Ecosimpro, and an experimental simulation is created to obtain the experimental results. Then, create a DECK model on the basis of the experiment, and configure the data that needs to be interacted with external clients. After the DECK model is successfully created, an OPC server is established and the relevant parameters of the OPC server are configured. After successfully registering the OPC server, connect the OPC client to test the real-time communication.

Claims (7)

1. a large-scale helium cryogenic system real-time simulation platform, is characterized in that: comprise the helium cryogenic system model established according to mechanism modeling and system identification method in Ecosimpro software, described helium cryogenic system model comprises compressor model, cold box model and load model; compressor model, cold box model and load model are connected to form a low temperature process model based on sequential method; a measurement sensor model based on mechanism modeling is also established in Ecosimpro software, and the measurement sensor model is added to the low temperature process model ; Also includes a control system model based on the EPICS architecture, the control system model includes a PID control module, an analog signal module, and a digital signal module, of which the PID control module uses IOC as a virtual controller to process data and implement control logic; in Ecosimpro An OPC server is established in the software, an OPC client is established in the IOC virtual controller, and the real-time communication between the low-temperature process model and the control system model is realized based on the OPC communication protocol; One PC is used as the system model server for storing the low-temperature process model and measurement sensor model, and another PC is used as the workstation for storing the control system model. In the workstation, the open source software CSS is used as the upper computer monitoring software and the IOC virtual controller. It is connected with the monitoring software of the upper computer through the Profibus bus. The monitoring software of the upper computer is equipped with control logic algorithm, database and monitoring interface, and the real-time communication based on the OPC communication protocol is realized physically between the system model server and the workstation through Ethernet. 2. a kind of large-scale helium cryogenic system real-time simulation platform according to claim 1, is characterized in that: described compressor model comprises but not limited to screw compressor, medium pressure helium gas storage tank model, high pressure and low pressure pipeline model and Pneumatic control valve model. 3. The real-time simulation platform for a large-scale helium cryogenic system according to claim 1, wherein the cold box model includes but is not limited to a turboexpander model, a multi-stream heat exchanger, an adsorber, a pipeline and a Pneumatic adjustment model. 4. a kind of large-scale helium cryogenic system real-time simulation platform according to claim 1, is characterized in that: described load model includes but is not limited to phase separator, cold press and regulating valve model. 5. a kind of large-scale helium cryogenic system real-time simulation platform according to claim 1, is characterized in that: described measurement sensor model includes but not limited to pressure sensor, temperature sensor, flow sensor and liquid level sensor. 6. a kind of large-scale helium cryogenic system real-time simulation platform according to claim 1, is characterized in that: according to the process flow and design parameter of existing helium cryogenic system, input compressor model, cold box model and load respectively in Ecosimpro software The basic design parameters of the model, the helium cryogenic system model is established in the Ecosimpro software according to the basic design parameters and based on mechanism modeling and system identification methods. 7. The real-time simulation platform for a large-scale helium cryogenic system according to claim 1, wherein the compressor model, the cold box model and the load model are connected based on the sequential method as follows: (1), two The storage devices are connected through thermal components; (2), a storage device and a thermal power device are connected through a series of thermal components.

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