Industrial control system of electric heating molten salt heat storage capable of accommodating fluctuations of wind and solar power generation

Abstract

This invention provides an industrial control system for electrically heated molten salt thermal energy storage that absorbs fluctuations in wind and solar power generation. Belonging to the fields of energy and electrical engineering, it includes a hardware architecture for the measurement and control of the electrically heated molten salt thermal energy storage system, a communication architecture for the system's equipment, and a software architecture for its measurement and control. This invention combines a stable hardware platform, an efficient communication architecture, and flexible industrial control algorithms to achieve real-time monitoring and industrial control of key parameters during the molten salt thermal energy storage process. While absorbing fluctuations in wind and solar power generation, it effectively improves the overall operating efficiency and reliability of the system, ensuring stable operation under different conditions and promoting the application and development of molten salt thermal energy storage technology in the field of large-scale energy storage.

Description

Technical Field

[0001] This invention belongs to the field of energy and electrical engineering, and specifically relates to an industrial control system for electrically heated molten salt thermal energy storage that absorbs fluctuations in wind and solar power generation. Background Technology

[0002] With the transformation of the global energy structure and the large-scale application of renewable energy, energy storage technology plays an increasingly important role in the power system. Electric heating molten salt thermal energy storage technology, as a highly efficient medium- and long-term energy storage technology, has become one of the important means of large-scale energy storage and dispatch due to its high energy density, good thermal stability, and high-temperature thermal storage capacity. Electric heating molten salt thermal energy storage systems need to absorb fluctuations in wind and solar power, but problems such as equipment failures, communication interruptions, and industrial control errors that may occur during operation can cause serious damage to the system. Summary of the Invention

[0003] To address the aforementioned technical challenges, this invention proposes an industrial control system for electrically heated molten salt thermal energy storage that absorbs fluctuations in wind and solar power generation. Combining a stable hardware platform, an efficient communication architecture, and flexible industrial control algorithms, this system enables real-time monitoring and industrial control of key parameters during the molten salt thermal energy storage process. This effectively improves the overall operating efficiency and reliability of the system while absorbing wind and solar power fluctuations, ensuring stable operation under various conditions and promoting the application and development of molten salt thermal energy storage technology in the field of large-scale energy storage.

[0004] This invention provides an industrial control system for electrically heated molten salt thermal energy storage that absorbs fluctuations in wind and solar power generation, comprising:

[0005] The hardware architecture for monitoring and control of an electrically heated molten salt thermal storage system includes a salt storage tank, a heat exchanger, a molten salt pump, a molten salt valve, an electric heat tracing device, an electric heater array, an electric heater power supply, sensor acquisition equipment, and an industrial controller. The outlet of the salt storage tank is connected to the molten salt pump. The molten salt pump is connected to the heat exchanger via a pipeline. The heat exchanger is connected back to the salt storage tank via a pipeline, forming a circulation loop. The pipeline is wound around the electric heat tracing device. The molten salt valve and the electric heater array powered by the electric heater power supply are installed on the pipeline. The sensor acquisition equipment is arranged on the salt storage tank, the molten salt pump, the pipeline, and the electric heater array. The molten salt pump, the molten salt valve, the electric heat tracing device, the sensor acquisition equipment, and the industrial controller are connected to a stable power supply. The electric heater power supply is connected to a fluctuating power supply.

[0006] The communication architecture of the electric heating molten salt thermal storage system includes a switch, an edge sensing industrial controller, and a human-machine interface. All devices are connected to the switch via network cables and communicate using a unified EtherNet / IP protocol. The sensing devices are connected to the edge sensing industrial controller, and the edge sensing industrial controller, the human-machine interface, the molten salt pump, the molten salt valve, the electric heat tracing, and the electric heater power supply are all communicatively connected to the industrial controller.

[0007] The monitoring and control software architecture of the electric heating molten salt thermal storage system is deployed in the industrial controller and is used for industrial control of the molten salt pump, molten salt valve, electric heat tracing and electric heater power supply. It includes a data preprocessing module, an operation mode judgment module, an industrial control mode judgment module, an output limiting module and an operation log generation module.

[0008] The electric heater power supply and the molten salt valve in the electric heater array are controlled by an industrial controller, while the molten salt pump, other molten salt valves and electric heat tracing are controlled by another industrial controller. The industrial controller combines scheduling information, power grid information, manual industrial control commands, sensor acquisition information and the operating status of each device to determine the operating parameters of each device, so as to keep the temperature of the molten salt entering the salt storage tank within a given threshold while absorbing wind and solar fluctuations.

[0009] The present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0010] (1) When absorbing wind and solar fluctuations, the equipment responsible for maintaining the basic operation of the system is connected to a stable power supply, and the equipment responsible for bearing the wind and solar fluctuations is connected to a fluctuating power supply, so as to effectively ensure the basic operational safety of the system.

[0011] (2) The system adopts hierarchical and zoned industrial control, and connects the corresponding industrial controllers according to the equipment functions and operating requirements, which facilitates troubleshooting when system malfunctions occur.

[0012] (3) All devices in the system are connected by network cables, which can effectively reduce communication failures caused by electromagnetic interference, etc. All devices use a unified communication protocol, which facilitates system development and management, and facilitates system self-testing and repair when communication connection problems occur.

[0013] (4) The industrial controller algorithm includes multi-layer system protection, which effectively improves the stability and security of the system when encountering problems such as equipment failure, communication interruption and industrial control adjustment error. Attached Figure Description

[0014] Figure 1 This is a hardware architecture diagram of the measurement and control system of the present invention.

[0015] Figure 2 This is a diagram of the communication architecture of the system devices of this invention.

[0016] Figure 3 This is a diagram of the system measurement and control software architecture of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the invention described below can be combined with each other as long as they do not conflict with each other. The technical solutions of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments.

[0018] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0019] This invention provides an industrial control system for electrically heated molten salt thermal energy storage that absorbs fluctuations in wind and solar power generation. The system includes a hardware architecture for measurement and control of the electrically heated molten salt thermal energy storage system, a communication architecture for the equipment of the electrically heated molten salt thermal energy storage system, and a software architecture for measurement and control of the electrically heated molten salt thermal energy storage system. The specific process is as follows:

[0020] Part One: Hardware Architecture for Measurement and Control of Electric Heating Molten Salt Thermal Storage System, such as Figure 1 As shown, it includes:

[0021] The electric heating molten salt thermal storage system mainly includes salt storage tanks (such as cold salt tanks, hot salt tanks, intermediate tanks, etc.), heat exchangers, molten salt pumps, molten salt valves, electric heat tracing, electric heater arrays, electric heater power supplies, sensor acquisition (such as temperature sensors, pressure sensors, liquid level sensors, flow sensors, vibration sensors, etc.), industrial controllers and other hardware equipment.

[0022] All salt storage tank outlets are equipped with molten salt pumps to pump the molten salt in the tanks into connecting pipelines. Cold salt tanks are connected to hot salt tanks via pipelines through intermediate tanks. Hot salt tanks are connected to heat exchangers via pipelines. After heat exchange is completed in the heat exchangers, the molten salt returns to the cold salt tanks via pipelines. All pipelines are wrapped with electric heat tracing to maintain the temperature of the molten salt inside the pipelines. Both sections of pipeline connecting the cold salt tanks to the hot salt tanks via intermediate tanks are equipped with molten salt valves and electric heater arrays powered by electric heaters. The molten salt valves assist the molten salt pumps in industrial control of the molten salt flow rate in the pipelines, and the electric heater arrays heat the molten salt to the set molten salt temperature for each salt storage tank.

[0023] All salt storage tanks are equipped with multiple temperature sensors at the bottom, middle, and top to monitor the temperature of the molten salt inside. A level sensor is also installed at the top to monitor the volume of molten salt within the tank. All molten salt pump outlets are equipped with flow sensors to monitor the flow rate of molten salt in the pipelines, and vibration sensors are installed on the casings of all molten salt pumps to monitor their operating status. All pipelines are equipped with multiple temperature sensors to monitor changes in the temperature of the molten salt within them. All electric heater arrays are equipped with multiple temperature sensors to monitor the temperature of the molten salt within the electric heaters.

[0024] To ensure the system can maintain normal operation while absorbing fluctuations in wind and solar power, it needs to be connected to a stable power source in addition to the fluctuating wind and solar power supply. Different devices in the system are connected to different power sources according to their functional requirements. Devices maintaining basic system operation, such as molten salt pumps, molten salt valves, electric heat tracing, sensor data acquisition, and industrial controllers, use plant power or draw power from the stable power grid. Devices primarily responsible for absorbing wind and solar power fluctuations, such as electric heater power supplies, are connected to the fluctuating power source to complete the absorption process.

[0025] To facilitate hierarchical and zoned industrial control of the system, devices that need to cooperate with each other are connected to the same industrial controller according to their functions. Devices such as the electric heater power supply and the molten salt valves in the electric heater array are controlled by one industrial controller, while the molten salt pump, other molten salt valves, and electric heat tracing devices are controlled by another industrial controller. If other devices in the system need to be connected to industrial control, they can be connected to the two aforementioned industrial controllers according to their functions, or a new industrial controller can be connected separately.

[0026] While supplying power to the electric heater array, the power supply also needs to handle wind and solar power fluctuations. The corresponding industrial controller for the electric heater power supply needs to combine multiple reference values, including dispatch information, grid information, manual industrial control commands, sensor data, and the operating status of each device, to determine the operating parameters of each electric heater power supply in the system. It then uses array industrial control algorithms, such as multi-agent game theory, to allocate the appropriate operating power to each electric heater unit in the array. In addition to mitigating wind and solar power fluctuations, the industrial controller also needs to coordinate with other devices in the system, such as adjusting molten salt valves in the electric heater array, to maintain the temperature of the molten salt entering each salt storage tank within a given threshold, thus ensuring the normal operation of the system.

[0027] Molten salt pumps, other molten salt valves, and electric heat tracing equipment are mainly responsible for maintaining the temperature of molten salt entering each salt storage tank within a given threshold. The corresponding industrial controller needs to combine manual industrial control commands, sensor data, and the operating status of each device as reference values ​​to determine the operating parameters of each molten salt pump, the opening degree of other molten salt valves, the switching on and off of electric heat tracing, and the operating power in the system.

[0028] Part Two: Communication Architecture of Electric Heating Molten Salt Thermal Storage System Equipment, such as Figure 2 As shown, it includes:

[0029] The electric heating molten salt thermal storage system mainly includes molten salt pumps, molten salt valves, electric heat tracing, electric heater power supplies, sensor acquisition, industrial controllers, human-machine interfaces and other equipment that need to be connected and communicate.

[0030] To ensure interoperability between devices, the system uses network cables and switches to connect them. All devices in the system communicate using the unified EtherNet / IP protocol. For devices using different connection methods and communication protocols, such as Modbus RTU or IEC61850, that need to connect to the system, a protocol conversion device can be connected to convert the connection method and communication protocol to the EtherNet / IP protocol consistent with the system, thus completing the communication access.

[0031] Due to the large number of sensing devices and the substantial amount of data, to facilitate communication and management, sensing devices of the same device and those physically adjacent to it are connected to the same edge sensing industrial controller. The edge sensing industrial controller is responsible for receiving and uploading data from each sensing device. For example, the sensing devices of a salt storage tank and its outlet molten salt pump are connected to the same edge sensing industrial controller; similarly, the sensing devices of the electric heater power supply, the electric heater array, and its molten salt valve are also connected to the same edge sensing industrial controller.

[0032] Sensors and data acquisition devices will upload information such as temperature, pressure, liquid level, flow rate, and vibration. Molten salt pumps, molten salt valves, electric heat tracing, and electric heater power supplies will upload equipment operating status information. Other upper-level devices such as PMU and EMS will upload information such as grid voltage, frequency, power factor, harmonics, and intraday scheduling. Human-machine interface devices will upload manual industrial control command information when there is human operation.

[0033] The industrial controller receives information uploaded by each device, adjusts the operating parameters of each device through algorithms, and uploads new device operating parameters and important node data in the adjustment algorithm.

[0034] The human-machine interface (HMI) device receives information uploaded from various devices and visualizes key data according to system operation monitoring needs. When manual industrial control of the system is required, the HMI device can be switched to manual mode, and manual industrial control commands can be correctly uploaded to achieve manual industrial control of the system.

[0035] The electric heater power supply, molten salt pump, molten salt valve, electric heat tracing and other equipment will receive the latest equipment operating parameters uploaded by the industrial controller and human-machine interface equipment and operate according to the corresponding parameters.

[0036] To ensure stable communication between devices, communication connection timeout protection must be added to the operating procedures of each device to prevent devices from operating without the system for extended periods. If a device fails to exchange information normally with other devices within the set communication timeout threshold, the system will record the communication anomaly and reset the relevant device. If communication is restored after the device is reset, the system will resume normal operation; otherwise, a communication anomaly warning will be sent to the human-machine interface and other monitoring devices to notify maintenance personnel to address the system issues promptly.

[0037] Part Three: The software architecture for monitoring and control of the electrically heated molten salt thermal storage system, such as... Figure 3 As shown, it includes:

[0038] The electric heating molten salt thermal storage system mainly includes equipment such as molten salt pumps, molten salt valves, electric heat tracing, and electric heater power supplies, all of which require industrial control. The industrial control algorithm for the equipment is handled by an industrial controller. The electric heater power supply and molten salt valves in the electric heater array are controlled by one industrial controller, while the molten salt pumps, other molten salt valves, and electric heat tracing equipment are controlled by another industrial controller.

[0039] After the industrial controller acquires the information uploaded by each device, it is necessary to preprocess the data that is prone to random errors to prevent the impact of random errors on the industrial control of the system. Considering that the electrically heated molten salt thermal storage system has strong thermal inertia and system inertia, and that data such as temperature and liquid level are not prone to sudden changes, a median filtering method is used to reduce the impact of random errors on the industrial control of the system.

[0040] After data filtering is completed, the system's operating mode needs to be determined to ensure safe system operation. If the system exceeds the safe operating range, the industrial controller will enter system protection mode, responding with corresponding emergency protection strategies and outputting relevant operating parameters for each device based on the situation exceeding the safe range. Conversely, the industrial controller will enter normal operation mode.

[0041] If the industrial controller operates in normal mode after completing the operating mode determination, then the system's industrial control mode needs to be determined. If the information uploaded by each device to the industrial controller includes manual industrial control commands from the HMI (Human Machine Interface) device, the industrial controller will enter manual industrial control mode, using the operating parameters of each device manually set by the HMI device. Otherwise, the industrial controller will enter automatic industrial control mode, adjusting the operating parameters of each device through adaptive industrial control algorithms such as MPC (Multi-Process Control).

[0042] If the industrial controller operates in normal mode and generates operating parameters for each device, in order to prevent unreasonable operation of the equipment caused by manually set or adaptive industrial control algorithm parameters, which could lead to equipment damage, it is necessary to limit the output of the operating parameters generated by the industrial controller to ensure safe output of each device operating parameter.

[0043] After the industrial controller outputs the operating parameters of each device, corresponding system operation logs need to be generated to facilitate system operation and maintenance management. The operation logs include information uploaded by each device after data preprocessing, the system operating mode, the system industrial control mode, and the operating parameters of each device output by the industrial controller. Subsequently, through big data analysis, machine learning model training, and other methods, the system's industrial control algorithm and operating strategy can be optimized. Finally, the industrial controller uploads new device operating parameters, completing one industrial control cycle.

[0044] To ensure system safety and prevent damage to equipment caused by prolonged abnormal operation, if the industrial controller operates in protection mode for an extended period and exceeds the set protection timeout threshold, the industrial controller will send an abnormal operation warning to the human-machine interface and other monitoring devices to notify maintenance personnel to address the relevant system issues promptly.

[0045] This invention also proposes an electronic system, including a memory, a processor, and a computer program stored in the memory and executable on the processor. It should be noted that each module in the above system corresponds to a specific step of the method provided in this invention, possessing the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in the method provided in this invention.

[0046] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or industrial controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or industrial controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0047] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. All components not explicitly stated in this embodiment can be implemented using existing technology.

Claims

1. An industrial control system for electrically heated molten salt thermal energy storage that absorbs fluctuations in wind and solar power generation, characterized in that, include: The hardware architecture for monitoring and control of an electrically heated molten salt thermal storage system includes a salt storage tank, a heat exchanger, a molten salt pump, a molten salt valve, an electric heat tracing device, an electric heater array, an electric heater power supply, sensor acquisition equipment, and an industrial controller. The outlet of the salt storage tank is connected to the molten salt pump. The molten salt pump is connected to the heat exchanger via a pipeline. The heat exchanger is connected back to the salt storage tank via a pipeline, forming a circulation loop. The pipeline is wound around the electric heat tracing device. The molten salt valve and the electric heater array powered by the electric heater power supply are installed on the pipeline. The sensor acquisition equipment is arranged on the salt storage tank, the molten salt pump, the pipeline, and the electric heater array. The molten salt pump, the molten salt valve, the electric heat tracing device, the sensor acquisition equipment, and the industrial controller are connected to a stable power supply. The electric heater power supply is connected to a fluctuating power supply. The communication architecture of the electric heating molten salt thermal storage system includes a switch, an edge sensing industrial controller, and a human-machine interface. All devices are connected to the switch via network cables and communicate using a unified EtherNet / IP protocol. The sensing devices are connected to the edge sensing industrial controller, and the edge sensing industrial controller, the human-machine interface, the molten salt pump, the molten salt valve, the electric heat tracing, and the electric heater power supply are all communicatively connected to the industrial controller. The monitoring and control software architecture of the electric heating molten salt thermal storage system is deployed in the industrial controller and is used for industrial control of the molten salt pump, molten salt valve, electric heat tracing and electric heater power supply. It includes a data preprocessing module, an operation mode judgment module, an industrial control mode judgment module, an output limiting module and an operation log generation module. The electric heater power supply and the molten salt valve in the electric heater array are controlled by an industrial controller, while the molten salt pump, other molten salt valves and electric heat tracing are controlled by another industrial controller. The industrial controller combines scheduling information, power grid information, manual industrial control commands, sensor acquisition information and the operating status of each device to determine the operating parameters of each device, so as to keep the temperature of the molten salt entering the salt storage tank within a given threshold while absorbing wind and solar fluctuations.

2. The system according to claim 1, characterized in that, The salt storage tank includes a cold salt tank, a hot salt tank, and an intermediate tank. The cold salt tank is connected to the hot salt tank via a pipeline through the intermediate tank. The hot salt tank is connected to the heat exchanger via a pipeline. The heat exchanger is connected back to the cold salt tank via a pipeline.

3. The system according to claim 1, characterized in that, The sensing and acquisition device includes a temperature sensor, a pressure sensor, a liquid level sensor, a flow sensor, and a vibration sensor; the temperature sensor is installed at the lower, middle, and upper parts of the salt storage tank, the liquid level sensor is installed at the top of the salt storage tank, the flow sensor is installed at the outlet of the molten salt pump, the vibration sensor is installed on the housing of the molten salt pump, and the temperature sensor is installed on the pipe and the electric heater array.

4. The system according to claim 1, characterized in that, The industrial controller corresponding to the electric heater power supply allocates operating power to each electric heater unit in the electric heater array.

5. The system according to claim 1, characterized in that, The device communication architecture also includes a protocol conversion device for converting devices using Modbus RTU or IEC61850 protocols into EtherNet / IP protocols before they can access the system.

6. The system according to claim 1, characterized in that, The edge sensing acquisition industrial controllers are arranged according to physical spatial distribution, and the sensing acquisition devices of the same device and the devices that are physically close to it are connected to the same edge sensing acquisition industrial controller.

7. The system according to claim 1, characterized in that, The data preprocessing module uses median filtering to process temperature and liquid level data in order to reduce the impact of random errors on the industrial control of the system.

8. The system according to claim 1, characterized in that, The operating mode determination module is used to determine whether the system exceeds the safe operating range. If it does, it enters the system protection mode and executes the emergency protection strategy. If it does not exceed the range, it enters the normal mode. The industrial control mode determination module is used to switch between manual industrial control mode and automatic industrial control mode in normal operating mode, depending on whether a manual industrial control command is received from the human-machine interface device.

9. The system according to claim 1, characterized in that, Each device's operating program has a communication connection timeout protection mechanism. When a device fails to perform normal information exchange within the set communication timeout threshold, the system records the communication abnormality and resets the relevant device. If communication is not restored after the reset, a communication abnormality warning is sent to the human-machine interface.

10. The system according to claim 1 or 8, characterized in that, The industrial controller is equipped with a protection timeout threshold. When the controller operates in protection mode for an extended period of time and exceeds this threshold, an abnormal operation warning is sent to the human-machine interface.

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