Electric pile temperature monitoring and control equipment of all-vanadium redox flow energy storage system

Abstract

The invention relates to the technical field of new energy storage, in particular to electric pile temperature monitoring and control equipment of an all-vanadium redox flow energy storage system. The system is composed of a distributed temperature sensing array, a multi-parameter coupling analysis module, a self-adaptive temperature regulation and control system, a main control unit, a double-circulation heat management framework and a fault diagnosis module. The control method comprises the following steps: establishing a pile three-dimensional temperature field reference model; monitoring temperature distribution and electrolyte parameters in real time; calculating an efficiency loss coefficient caused by the local temperature difference; dynamically adjusting the refrigeration power and the pump set rotating speed; and executing temperature balance degree verification and system self-inspection. The invention provides an electric pile temperature management scheme integrating high-precision three-dimensional temperature monitoring, multi-parameter dynamic coupling regulation and control and intelligent fault diagnosis so as to solve the problems of monitoring blind areas, regulation and control delay, insufficient risk prediction capability and the like in the prior art, thereby improving the operation efficiency and safety of an all-vanadium redox flow energy storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy energy storage, and in particular to an electric stack temperature monitoring and control device for a all-vanadium redox flow energy storage system. Background Art

[0002] As a highly efficient and long-life large-scale energy storage technology, the vanadium redox flow battery (VRFB) has important application value in the fields of renewable energy grid connection and power grid peak shaving. Its core component, the electric stack, realizes energy storage and release through the oxidation-reduction reaction of vanadium ions in the electrolyte. The temperature distribution of the electric stack directly affects the ion migration rate, electrolyte stability, and overall system efficiency. An uneven temperature field is likely to cause problems such as local overheating, electrolyte crystallization, or thermal aging of materials, and may even lead to system failures in severe cases. Therefore, accurate temperature monitoring and control are the keys to ensuring the reliable operation of the all-vanadium redox flow energy storage system.

[0003] Currently, traditional electric stack temperature management technologies have the following limitations: (1) Single monitoring means: Existing systems mostly use discrete thermocouples or single-type sensors, which can only obtain temperature data at limited points, making it difficult to construct a real-time monitoring network for the three-dimensional temperature field and unable to comprehensively reflect the internal temperature gradient distribution of the electric stack. (2) Delayed regulation response: Conventional temperature control systems rely on fixed thresholds to trigger cooling or heating, lacking multi-parameter collaborative analysis of electrolyte flow rate, voltage fluctuations, and ambient temperature and humidity, resulting in poor adaptability of regulation strategies and difficulty in coping with dynamic operating conditions. (3) Insufficient thermal management efficiency: Traditional single-cycle cooling architectures are difficult to achieve hierarchical heat management. Especially in high-temperature or high-load operating conditions, heat accumulation is likely to occur, and the matching flexibility of existing heat exchangers and pump sets is insufficient, leading to reduced energy efficiency. (4) Passive fault diagnosis: Existing technologies mostly rely on threshold alarm mechanisms, lacking the ability to predict abnormal temperature trends and unable to early warn of risks such as electrolyte crystallization or thermal shock. System maintenance relies on post-event processing, and reliability is limited. Summary of the Invention

[0004] The present invention proposes an electric stack temperature management solution integrating high-precision three-dimensional temperature monitoring, multi-parameter dynamic coupling regulation, and intelligent fault diagnosis to solve problems such as monitoring blind spots, regulation lags, and insufficient risk prediction ability in the prior art, thereby improving the operating efficiency and safety of the all-vanadium redox flow energy storage system.

[0005] The technical solution adopted by the present invention is: An electric stack temperature monitoring and control device for an all-vanadium redox flow energy storage system, which is composed of a distributed temperature sensing array, a multi-parameter coupling analysis module, an adaptive temperature regulation system, a main control unit, a double-cycle thermal management framework, and a fault diagnosis module.

[0006] The distributed temperature sensing array consists of an optical fiber temperature sensor embedded between the stack cells, an infrared thermal imaging module, and a thermocouple in the electrolyte pipeline to form a three-dimensional monitoring network;

[0007] The multi-parameter coupling analysis module integrates an electrolyte flow rate sensor, a voltage inspection unit, and an environmental temperature and humidity monitor;

[0008] The adaptive temperature control system includes a semiconductor thermoelectric cooling sheet array, a microchannel plate heat exchanger, and a variable-frequency circulating pump set;

[0009] The main control unit is configured with a dynamic balance model of the temperature field based on the fuzzy PID algorithm, which processes sensor data in real time and generates control instructions;

[0010] The dual-cycle thermal management architecture includes an independent internal cycle electrolyte temperature control subsystem and an external cycle coolant regulation system;

[0011] The fault diagnosis module realizes system protection through temperature gradient anomaly detection and thermal shock prediction algorithms.

[0012] As a further improvement of the present invention, the distributed temperature sensing array uses a 0.2 mm diameter corrosion-resistant optical fiber sensor embedded between the bipolar plates of each layer of the stack; an infrared thermal imager integrated at the four corners of the stack frame with a resolution ≤ 0.1 °C; and a T-type armored thermocouple arranged in the electrolyte inlet and outlet pipelines with a sampling frequency ≥ 10 Hz.

[0013] As a further improvement of the present invention, the multi-parameter coupling analysis module establishes a three-dimensional correlation matrix of temperature - flow rate - voltage, eliminates sensor noise interference through the Kalman filtering algorithm, and predicts the change trend of ion mobility caused by local temperature difference.

[0014] As a further improvement of the present invention, the adaptive temperature control system includes a thermoelectric cooling sheet array mounted on the side of the stack with an adjustable single-unit cooling power of 50 - 200 W; a dynamic bypass valve is set between the microchannel heat exchanger and the electrolyte pipeline; and the circulating pump set has a stepless speed regulation function of 0 - 100%.

[0015] As a further improvement of the present invention, the internal cycle system of the dual-cycle thermal management architecture uses ethylene glycol solution and electrolyte for countercurrent heat exchange, the external cycle system is connected to a phase change energy storage device and an air cooling tower, and heat hierarchical management is realized through a plate heat exchanger between the two-stage cycles.

[0016] As a further improvement of the present invention, the main control unit is configured with a temperature compensation algorithm based on electrochemical impedance spectroscopy, dynamically adjusts the polarity of the thermoelectric cooling sheet to realize the heating / cooling mode switch, generates a three-dimensional temperature field cloud map and visualizes it.

[0017] As a further improvement of the present invention, the fault diagnosis module has a temperature anomaly prediction function based on an LSTM neural network, an electrolyte crystallization risk warning mechanism, and the hierarchical alarm system includes an audible and visual alarm and a remote communication interface.

[0018] As a further improvement of the present invention, the stack frame is provided with a heat-insulating and heat-preserving layer, the heat conduction system ≤ 0.03 W / (m·k), and is equipped with an emergency heat dissipation air duct and a flame-retardant fire extinguishing device, and supports parallel expansion of multiple stacks.

[0019] A control method for an electric stack temperature monitoring and control device of a vanadium redox flow energy storage system, comprising the following steps:

[0020] S1: In the system initialization stage, a three-dimensional temperature field reference model is constructed based on the historical operation data of the stack and the coefficient of thermal expansion of the material, and the temperature weight coefficient of each monitoring point is determined through finite element analysis;

[0021] S2: Locally collect the temperature data of the distributed temperature sensing array, the electrolyte flow rate and the voltage fluctuation value of the multi-parameter coupling analysis module in real time, and perform data normalization processing using the sliding time window algorithm;

[0022] S3: Calculate the ion transport efficiency loss coefficient η caused by the current temperature gradient through the thermoelectric coupling equation. When η > 5%, trigger the temperature difference compensation mechanism, and generate a dynamic regulation threshold according to the electrolyte viscosity-temperature characteristic curve;

[0023] S4: Dynamically adjust the refrigeration power distribution map of the semiconductor thermoelectric cooler based on the fuzzy PID algorithm, and at the same time coordinate the control of the bypass valve opening of the microchannel heat exchanger and the frequency conversion parameters of the circulating pump group to stabilize the surface temperature difference of the stack within the range of ±1°C;

[0024] S5: After each regulation cycle, use the infrared thermal imaging module to verify the temperature field uniformity. If local overheating / cooling areas are detected continuously for 3 times, start the system self-check program and update the control parameter library.

[0025] As a further improvement of the present invention, in S3, when the local temperature > 2°C is detected, the gradient compensation mode is started; when the electrolyte temperature deviates from the set value by ±1°C, active temperature control is triggered; when the ambient temperature suddenly changes, preventive regulation is started 30 minutes in advance.

[0026] Advantages of the present invention: (1) High-precision three-dimensional temperature monitoring and real-time feedback: By integrating fiber optic sensors, infrared thermal imaging modules, and armored thermocouples through a distributed temperature sensing array, the present invention constructs a three-dimensional monitoring network, which can accurately capture the temperature gradient in the micro-regions between layers inside the stack (resolution ≤ 0.1 °C) and the dynamic temperature changes in the electrolyte pipeline (sampling frequency ≥ 10 Hz), realizing real-time mapping of the temperature field with full-space coverage. Compared with traditional discrete sensors, the temperature monitoring blind area is reduced by more than 80%, providing reliable data support for precise regulation.

[0027] (2) Multi-parameter dynamic collaborative regulation and energy efficiency optimization: Based on the fuzzy PID algorithm and thermo-electric coupling equations, the main control unit of the present invention fuses temperature, flow rate, voltage, and environmental parameters in real-time, dynamically generating a refrigeration power distribution map and pump speed regulation instructions, so that the temperature difference on the surface of the stack is stabilized within the range of ±1 °C. Combining the hierarchical heat exchange strategy of the double-cycle thermal management architecture (internal cycle countercurrent heat exchange + external cycle phase change energy storage), the system energy efficiency is increased by more than 30%, and the problem of heat accumulation under high-temperature conditions is effectively avoided.

[0028] (3) Intelligent fault warning and active protection mechanism: The fault diagnosis module of the present invention integrates the LSTM neural network and the temperature gradient anomaly detection algorithm, which can predict the risk of electrolyte crystallization or thermal shock events 30 minutes in advance, and realizes active intervention through a hierarchical alarm system (acoustic and optical alarm + remote communication). Compared with the traditional threshold alarm mechanism, the system failure rate is reduced by 50%, and the maintenance cost is reduced by 40%, significantly improving the operation reliability.

[0029] (4) Modular design and expansion compatibility: The stack frame of the present invention adopts an adiabatic insulation layer (thermal conductivity ≤ 0.03 W / (m·K)) and a rapid heat dissipation air duct design, supporting the independent temperature control requirements during the parallel expansion of multiple stacks. At the same time, the dynamic bypass valve and stepless speed regulation pump group of the adaptive regulation system can be flexibly adapted to different-scale energy storage systems, reducing the equipment transformation cost and having strong expandability. Description of the Drawings

[0030] Figure 1 is the overall system block diagram of the stack temperature monitoring and control device of a vanadium redox flow energy storage system of the present invention;

[0031] Figure 2 is the system block diagram of the double-cycle thermal management architecture of the stack temperature monitoring and control device of a vanadium redox flow energy storage system of the present invention;

[0032] Figure 3 is the control method flow chart of the stack temperature monitoring and control device of a vanadium redox flow energy storage system of the present invention. Detailed Embodiments

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] The present invention provides an electric stack temperature monitoring and control device for a vanadium redox flow energy storage system, which is composed of a distributed temperature sensing array, a multi-parameter coupling analysis module, an adaptive temperature regulation system, a main control unit, a double-cycle thermal management framework and a fault diagnosis module.

[0035] In the present invention, the distributed temperature sensing array consists of a fiber optic temperature sensor embedded between the electric stack units, an infrared thermal imaging module and a thermocouple for the electrolyte pipeline to form a three-dimensional monitoring network. The distributed temperature sensing array uses a 0.2 mm diameter anti-corrosive fiber optic sensor embedded between the bipolar plates of each layer of the electric stack; an infrared thermal imager integrated at the four corners of the electric stack frame, with a resolution ≤ 0.1 °C; a T-shaped armored thermocouple is arranged on the electrolyte inlet and outlet pipelines, and the sampling frequency ≥ 10 Hz.

[0036] In the present invention, the multi-parameter coupling analysis module integrates an electrolyte flow rate sensor, a voltage inspection unit and an ambient temperature and humidity monitor. The multi-parameter coupling analysis module establishes a three-dimensional correlation matrix of temperature - flow rate - voltage, eliminates sensor noise interference through the Kalman filtering algorithm, and predicts the change trend of ion mobility caused by local temperature difference.

[0037] In the present invention, the adaptive temperature regulation system includes a semiconductor thermoelectric refrigeration sheet array, a microchannel plate heat exchanger and a variable-frequency circulating pump group. The adaptive temperature regulation system includes a thermoelectric refrigeration sheet array mounted on the side of the electric stack, with an adjustable single-unit refrigeration power of 50 - 200 W; a dynamic bypass valve is set between the microchannel heat exchanger and the electrolyte pipeline; the circulating pump group has a stepless speed regulation function of 0 - 100%.

[0038] In the present invention, the main control unit is configured with a temperature field dynamic balance model based on the fuzzy PID algorithm, which processes sensor data in real time and generates control instructions. The main control unit is configured with a temperature compensation algorithm based on electrochemical impedance spectroscopy, dynamically adjusts the polarity of the thermoelectric refrigeration sheet to realize the switching of heating / cooling modes, and generates a three-dimensional temperature field cloud map for visual display.

[0039] In the present invention, the double-cycle thermal management architecture includes an independent inner-cycle electrolyte temperature control subsystem and an outer-cycle coolant regulation system. The inner-cycle system of the double-cycle thermal management architecture uses ethylene glycol solution to exchange heat with the electrolyte in a countercurrent manner. The outer-cycle system is connected to a phase change energy storage device and an air cooling tower, and heat hierarchical management is realized through a plate heat exchanger between the two-stage cycles.

[0040] In the present invention, the fault diagnosis module realizes system protection through temperature gradient anomaly detection and thermal shock prediction algorithms. The fault diagnosis module has a temperature anomaly prediction function based on the LSTM neural network, an electrolyte crystallization risk warning mechanism, and a hierarchical alarm system including an acoustic-optic alarm and a remote communication interface.

[0041] In the present invention, the stack frame is provided with a heat-insulating layer, the heat conduction system ≤ 0.03 W / (m·k), and is equipped with an emergency heat dissipation air duct and a flame-retardant fire extinguishing device, and supports the parallel expansion of multiple stacks.

[0042] A control method for an electric stack temperature monitoring and control device of a all-vanadium redox flow energy storage system includes the following steps:

[0043] S1: In the system initialization stage, a three-dimensional temperature field reference model is constructed based on the historical operation data of the stack and the material thermal expansion coefficient, and the temperature weight coefficients of each monitoring point are determined through finite element analysis;

[0044] S2: Locally collect the temperature data of the distributed temperature sensing array, the electrolyte flow rate and voltage fluctuation values of the multi-parameter coupling analysis module in real time, and perform data normalization processing using the sliding time window algorithm;

[0045] S3: Calculate the ion transport efficiency loss coefficient η caused by the current temperature gradient through the thermoelectric coupling equation. When η > 5%, trigger the temperature difference compensation mechanism, and generate a dynamic regulation threshold according to the electrolyte viscosity-temperature characteristic curve. When the detected local temperature > 2°C, start the gradient compensation mode; when the electrolyte temperature deviates from the set value by ±1°C, trigger active temperature control; when the ambient temperature suddenly changes, start preventive regulation 30 minutes in advance;

[0046] S4: Dynamically adjust the cooling power distribution map of the semiconductor thermoelectric cooler based on the fuzzy PID algorithm, and at the same time coordinate the control of the bypass valve opening of the microchannel heat exchanger and the frequency conversion parameters of the circulating pump group to keep the surface temperature difference of the stack stable within the range of ±1°C;

[0047] S5: After each regulation cycle, use the infrared thermal imaging module to verify the temperature field uniformity. If local overheating / cooling areas are detected continuously for 3 times, start the system self-check program and update the control parameter library.

[0048] Embodiment:

[0049] This embodiment combines a specific application scenario to detail the implementation manner of an electric stack temperature monitoring and control device of the present invention for a all-vanadium redox flow energy storage system. This embodiment takes a 20kW / 100kWh all-vanadium redox flow energy storage system as an example, configured with 5 parallel stack units, each stack consisting of 50 layers of bipolar plates, the electrolyte flow rate range is 10 - 50 L / min, and the ambient temperature fluctuation range is -10°C to 40°C.

[0050] (1) System Hardware Configuration and Initialization

[0051] Distributed temperature sensing array: Embedded between each pair of bipolar plates are 0.2-mm diameter corrosion-resistant fiber optic sensors (model FOT-100, temperature measurement range -20°C to 80°C, accuracy ±0.05°C), with a total of 250 measurement points; infrared thermal imagers (model FLIRA615, resolution 0.05°C, frame rate 30 Hz) are installed at the four corners of the stack frame; T-type armored thermocouples (sampling frequency 15 Hz) are arranged in the electrolyte inlet and outlet pipelines, with a total of 4 groups.

[0052] Dual-loop thermal management architecture: The inner-loop subsystem uses ethylene glycol solution (concentration 40%) to exchange heat countercurrently with the electrolyte, and the flow rate is controlled by a stepless speed regulation pump group (power 0.5 - 5 kW); the outer-loop system is connected to a phase change energy storage device (paraffin-based phase change material, phase change temperature 35°C) and an air cooling tower (heat dissipation power 20 kW), and heat transfer is carried out between the two loops through a plate heat exchanger (heat transfer area 2 m 2 ).

[0053] Adaptive temperature control system: An array of semiconductor thermoelectric cooling chips (single-chip cooling power 200 W, a total of 20 chips) is installed on the side of the stack, and a dynamic bypass valve (opening degree adjustable from 0 - 100%) is set between the microchannel plate heat exchanger (channel width 0.5 mm) and the electrolyte pipeline.

[0054] (2) Implementation Process of the Control Method

[0055] Step S1: Construction of the 3D Temperature Field Benchmark Model

[0056] Based on the historical operation data of the stack (including electrolyte temperature, flow rate, voltage, and ambient temperature and humidity), combined with the physical properties of the bipolar plate material (graphite composite material, thermal expansion coefficient 2.3×10 -6 / °C), a 3D temperature field benchmark model is established through finite element analysis software (ANSYS Mechanical), and the temperature weight coefficients of each monitoring point are determined (weight range 0.8 - 1.2).

[0057] Step S2: Multi-source Data Acquisition and Processing

[0058] Local temperature data of the fiber optic sensors, infrared thermal imagers, and thermocouples are collected in real time (sampling period 0.1 s), and the electrolyte flow rate (electromagnetic flowmeter, accuracy ±0.5%), voltage fluctuation value (voltage inspection unit, accuracy ±0.1 V), and ambient temperature and humidity (sensor model SHT35, accuracy ±1% RH) are obtained synchronously. The sliding time window algorithm (window length 10 s, sliding step 1 s) is used to normalize the data to eliminate the dimension difference.

[0059] Step S3: Thermo - electric coupling analysis and dynamic regulation

[0060] Calculate the ion transport efficiency loss coefficient η through the thermo - electric coupling equation (Formula 1):

[0061] where α = 0.015, β = 0.2, ΔT is the local temperature difference, and dV / dt is the voltage change rate. When η > 5%, the main control unit generates a dynamic regulation threshold according to the electrolyte viscosity - temperature characteristic curve (viscosity is 3.2 mPa·s at 25°C, and the viscosity decreases by 0.12 mPa·s for every 1°C increase), and triggers the following compensation mechanisms:

[0062] (1) Local temperature difference > 2°C: Start the gradient compensation mode, and directionally increase the power of the thermoelectric cooler in the corresponding area (boost to 150 W);

[0063] (2) The electrolyte temperature deviates from the set value by ±1°C: Adjust the opening of the bypass valve (increase the opening by 20%) and the rotational speed of the pump group (boost to 80%);

[0064] (3) Sudden change in ambient temperature (such as a sudden increase of 10°C): Start the external circulation phase - change energy storage device 30 minutes in advance to reduce the risk of thermal shock.

[0065] Step S4: Dynamic regulation by fuzzy PID algorithm

[0066] The main control unit generates a refrigeration power distribution map (as shown) based on the fuzzy PID algorithm (proportional coefficient Kp = 0.8, integral time Ti = 120 s, derivative time Td = 30 s), and cooperatively controls the opening of the bypass valve of the micro - channel heat exchanger (adjustment accuracy ±2%) and the frequency conversion parameters of the circulating pump group (frequency range 5 - 50 Hz) to keep the temperature difference on the surface of the fuel cell stack stable within the range of ±1°C. Measured data shows that after the fuel cell stack operates for 1 hour, the maximum temperature difference drops from ±3.5°C of the traditional system to ±0.8°C. Figure 3 shown

[0067] Step S5: Verification and self - inspection of temperature field uniformity

[0068] After each regulation cycle (30 minutes) ends, generate a three - dimensional temperature field cloud map through the infrared thermal imaging module (as shown). If local overheating areas (such as the temperature between a certain bipolar plate > 40°C) are detected continuously for 3 times, the main control unit starts the system self - inspection program, updates the control parameter library (such as adjusting the weight coefficient or optimizing the fuzzy rules), and sends a warning signal to the remote monitoring platform through the fault diagnosis module. Figure 1 shown

[0069] (III) Verification of implementation effect

[0070] (1) Temperature control accuracy: The temperature difference on the surface of the stack is stabilized within ±1°C, the temperature gradient in the local micro-region ≤ 0.5°C / cm, and the risk of electrolyte crystallization is reduced by 90%;

[0071] (2) Energy efficiency improvement: The dual-cycle thermal management architecture enables the overall energy efficiency of the system to reach 85%, a 32% increase compared to the traditional single-cycle system;

[0072] (3) Fault warning ability: The prediction accuracy of the LSTM neural network model for electrolyte crystallization events reaches 95%, and the fault response time is shortened to within 5 minutes;

[0073] (4) Scalability test: The system is successfully expanded to 10 parallel stacks (total power 40kW), and the independent temperature control error of each stack < ±1.2°C, verifying the compatibility of the modular design.

[0074] (IV) Comparative experiment

[0075] Comparative test with the traditional temperature control system (under the same working conditions):

[0076] Index Traditional system System of the present invention Temperature difference of the stack (±°C) 3.5 0.8 Energy efficiency (%) 53 85 Fault response time (min) 60 (threshold alarm) 5 (active early warning) Maintenance cost (10,000 yuan / year) 12 7.2

[0077] Conclusion: This embodiment verifies the significant advantages of the present invention in high-precision temperature monitoring, multi-parameter collaborative regulation, and intelligent fault warning, which can effectively improve the operation stability and economy of the all-vanadium redox flow energy storage system and is applicable to scenarios such as large-scale energy storage power stations and distributed energy systems.

[0078] In summary, through the comparative experimental data of the stack temperature monitoring and control equipment of the all-vanadium redox flow energy storage system of the present invention, it can be clearly seen that the present invention has significant advantages over the traditional temperature control system in multiple key indicators. First, in terms of temperature control accuracy, the traditional system often has difficulty in controlling the stack temperature difference at a low level, while the present invention successfully reduces the stack temperature difference to ±0.8°C through three-dimensional temperature field monitoring and dynamic regulation of the fuzzy PID algorithm, greatly improving the temperature uniformity and operation stability of the system.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electric stack temperature monitoring and control device for an all-vanadium redox flow energy storage system, characterized in that: It consists of a distributed temperature sensing array, a multi-parameter coupling analysis module, an adaptive temperature regulation system, a main control unit, a dual-cycle thermal management framework, and a fault diagnosis module. The distributed temperature sensing array consists of an optical fiber temperature sensor embedded between the stack cells, an infrared thermal imaging module, and a thermocouple in the electrolyte pipeline to form a three-dimensional monitoring network. The multi-parameter coupling analysis module integrates an electrolyte flow rate sensor, a voltage inspection unit, and an ambient temperature and humidity monitor. The adaptive temperature regulation system includes a semiconductor thermoelectric cooling sheet array, a microchannel plate heat exchanger, and a variable-frequency circulating pump group. The main control unit is configured with a dynamic balance model of the temperature field based on the fuzzy PID algorithm, which processes sensor data in real time and generates control instructions. The dual-cycle thermal management framework includes an independent inner-cycle electrolyte temperature control subsystem and an outer-cycle coolant regulation system. The fault diagnosis module realizes system protection through temperature gradient anomaly detection and thermal shock prediction algorithms.

2. The stack temperature monitoring and control device for an all-vanadium redox flow energy storage system according to claim 1, characterized in that: The distributed temperature sensing array uses a 0.2-mm diameter corrosion-resistant optical fiber sensor embedded between the bipolar plates of each layer of the stack; an infrared thermal imager integrated at the four corners of the stack frame with a resolution ≤ 0.1 °C; and a T-type armored thermocouple arranged in the electrolyte inlet and outlet pipelines with a sampling frequency ≥ 10 Hz.

3. The stack temperature monitoring and control device for an all-vanadium redox flow energy storage system according to claim 1, characterized in that: The multi-parameter coupling analysis module establishes a three-dimensional correlation matrix of temperature-flow rate-voltage, eliminates sensor noise interference through the Kalman filtering algorithm, and predicts the change trend of ion mobility caused by local temperature differences.

4. The electric stack temperature monitoring and control device for a all-vanadium redox flow energy storage system according to claim 1, characterized in that: The adaptive temperature regulation system includes a thermoelectric cooling sheet array mounted on the side of the stack with an adjustable single-unit cooling power of 50-200 W; a dynamic bypass valve is set between the microchannel heat exchanger and the electrolyte pipeline; the circulating pump group has a stepless speed regulation function of 0-100%.

5. The electric stack temperature monitoring and control device of an all-vanadium redox flow energy storage system according to claim 1, characterized in that: The inner-cycle system of the dual-cycle thermal management framework uses ethylene glycol solution and electrolyte for countercurrent heat exchange. The outer-cycle system is connected to a phase change energy storage device and an air cooling tower, and heat hierarchical management is realized through a plate heat exchanger between the two-stage cycles.

6. The electric stack temperature monitoring and control device of a all-vanadium redox flow energy storage system according to claim 1, characterized in that: The main control unit is configured with a temperature compensation algorithm based on electrochemical impedance spectroscopy, dynamically adjusts the polarity of the thermoelectric cooling sheet to realize the heating / cooling mode switch, generates a three-dimensional temperature field cloud map and visualizes it.

7. The stack temperature monitoring and control device for an all-vanadium redox flow energy storage system according to claim 1, characterized in that: The fault diagnosis module has a temperature anomaly prediction function based on the LSTM neural network, an electrolyte crystallization risk warning mechanism, and a hierarchical alarm system including audible and visual alarms and a remote communication interface.

8. The stack temperature monitoring and control device for a all-vanadium redox flow energy storage system according to claim 1, characterized in that: The stack frame is provided with an adiabatic insulation layer with a thermal conductivity ≤ 0.03 W / (m·k), and is equipped with an emergency heat dissipation air duct and a flame-retardant fire extinguishing device, supporting parallel expansion of multiple stacks.

9. A control method for an electric stack temperature monitoring and control device of a all-vanadium redox flow energy storage system, characterized in that: It includes the following steps: S1: In the system initialization stage, a three-dimensional temperature field reference model is constructed based on the historical operation data of the stack and the material thermal expansion coefficient, and the temperature weight coefficients of each monitoring point are determined through finite element analysis. S2: Real-time collect the local temperature data of the distributed temperature sensing array, the electrolyte flow rate and voltage fluctuation values of the multi-parameter coupling analysis module, and perform data normalization processing using the sliding time window algorithm. S3: Calculate the ion transmission efficiency loss coefficient η caused by the current temperature gradient through the thermal-electric coupling equation. When η>5%, the temperature difference compensation mechanism is triggered, and a dynamic control threshold is generated according to the electrolyte viscosity-temperature characteristic curve; S4: Dynamically adjust the cooling power distribution map of the semiconductor thermoelectric refrigeration chip based on the fuzzy PID algorithm, and coordinately control the bypass valve opening of the microchannel heat exchanger and the frequency conversion parameters of the circulation pump group to stabilize the surface temperature difference of the battery stack within the range of ±1°C; S5: After each control cycle, the infrared thermal imaging module is used to verify the temperature field balance. If a local overheating / overcooling area is detected three times in a row, the system self-check program is started and the control parameter library is updated.

10. The control method of the stack temperature monitoring and control device for an all-vanadium redox flow energy storage system according to claim 9, characterized in that: In S3, when the local temperature is detected to be greater than 2°C, the gradient compensation mode is started; when the electrolyte temperature deviates from the set value by ±1°C, active temperature control is triggered; when the ambient temperature suddenly changes, preventive control is started 30 minutes in advance.

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