A cooling system and method for a fuel cell slurry configuration process

Abstract

The application discloses a cooling system and method in a fuel cell slurry configuration process, and belongs to the technical field of fuel cell MEA coating preparation. The system comprises a stirring container, a stirrer, a spiral cooling pipe, a temperature sensor, an online viscosity detector and a controller. The spiral cooling pipe is fixedly connected with the stirrer and synchronously moves with the stirrer, and the helical rise angle of the spiral cooling pipe is 15°-45°. The controller is internally provided with a viscosity compensation model, the PID control parameters are dynamically compensated according to the real-time viscosity of the slurry, and the cooling medium flow and temperature are cooperatively adjusted in combination with the matching relationship between the stirring speed and the helical rise angle. Through the cooperative optimization of the structural parameters and the process parameters and the viscosity self-adaptive temperature control, the application significantly improves the accuracy and stability of the cooling process of the slurry with different viscosities, effectively prevents the catalyst from agglomerating and improves the quality of the slurry.

Description

Technical Field

[0001] This invention relates to the field of coating preparation technology for fuel cell MEA (membrane electrode assembly), and in particular to a cooling system and method in the fuel cell slurry preparation process. Background Technology

[0002] A fuel cell is a non-combustion electrochemical energy conversion device that combines the characteristics of a battery and a heat engine. It features high energy conversion efficiency, no environmental pollutant emissions, rapid low-temperature start-up, and low vibration and noise levels. Therefore, fuel cells are considered one of the new environmentally friendly and efficient power generation technologies of the 21st century. In a fuel cell system, the quality of the MEA (membrane electrode assembly) significantly affects power generation performance. In particular, the electrode coatings that constitute the positive and negative electrodes of the MEA play a decisive role in the overall quality of the MEA. Because these coatings typically contain precious metal catalysts such as platinum, the material cost is relatively high.

[0003] In membrane electrode coating processes, nano-sized noble metal catalyst particles and carbon powder particles are typically dispersed in organic solvents such as isopropanol and ethanol to prepare a catalyst suspension slurry. Since catalyst powder particles easily settle or agglomerate into large particles in solvents, continuous stirring and dispersion of the catalyst slurry is necessary to prevent this. Typically, during electrode forming, an electrode coating is prepared and applied first; therefore, quality control and defect elimination of the coating are particularly important during the stirring process preceding this step.

[0004] In the dispersion process of MEA coatings, high-speed dispersion or ultrasonic dispersion methods are typically used. These two methods provide strong dispersion forces, and the stirred liquid can be easily heated using the heat generated by stirring. However, the catalyst slurry is highly sensitive to temperature; higher temperatures increase the likelihood of catalyst particle agglomeration and bubble formation, severely impacting the catalyst coating process. Therefore, cooling must be performed simultaneously with stirring to maintain the slurry temperature within a suitable range (typically below 25°C).

[0005] In existing technologies, the main methods for cooling catalyst slurry are as follows: One method is to use a cooling jacket to cool the mixing vessel. This involves installing a jacket on the outside of the mixing vessel, with a cooling medium flowing through it, exchanging heat with the slurry through the vessel wall. However, this method has significant drawbacks: firstly, vessels with cooling jackets are expensive to manufacture and have complex structures; secondly, jacketed vessels present difficulties in metering, making it hard to accurately control the volume and weight of the slurry; and thirdly, jacketed vessels are typically bulky, inconvenient to transport and handle, leading to numerous operational problems.

[0006] Another approach involves incorporating cooling channels within the stirring shaft, introducing a cooling medium through the hollow shaft to achieve internal cooling. For instance, Chinese patent application CN102593470A discloses an apparatus for preparing a proton exchange membrane fuel cell diffusion layer slurry, which achieves internal cooling by introducing circulating water through a pipeline installed within a hollow high-speed drive shaft. However, this approach suffers from limited cooling area and low cooling efficiency due to the cooling channels being located inside the stirring shaft, making it difficult to meet the cooling demands under high-speed, high-heat-generating conditions. Furthermore, this approach lacks temperature sensors and an automatic control system, preventing dynamic adjustment of the cooling process based on the real-time slurry temperature, resulting in low temperature control accuracy.

[0007] Another approach is to use a cold trap for circulating cooling of the slurry preparation vessel. For example, Chinese patent application CN115069183A discloses a method and apparatus for processing catalyst slurry, which uses a controlled cold trap to circulate and cool the slurry preparation vessel. However, this approach requires additional cold trap equipment, making the system complex, and the cold trap is usually located outside the slurry preparation vessel, limiting the cooling effect to the heat transfer efficiency of the vessel wall.

[0008] In addition, existing technologies also employ coil-type cooling structures for cooling. For example, a slurry cooling device includes a spiral coil, where the slurry exchanges heat with cooling water in the cooling chamber as it enters the spiral coil. However, in this approach, the spiral coil is fixedly installed in the cooling chamber, and the slurry flows through the inside of the coil for cooling. This is a tube-side cooling method and is not suitable for in-situ cooling of slurry within a mixing vessel.

[0009] In summary, existing technologies lack a fuel cell slurry cooling system that can work in conjunction with a stirrer, possess high cooling efficiency, and adaptively and intelligently control the temperature based on the real-time temperature and viscosity of the slurry. Specifically, existing technologies do not include a method that fixes a spiral cooling pipe with a specific helix angle to the stirrer and moves synchronously with it, while simultaneously incorporating a temperature control scheme that compensates for slurry viscosity, thus achieving a balance between efficient cooling and precise temperature control during stirring. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the present invention aims to provide a cooling system and method for the fuel cell slurry preparation process. This system enhances heat transfer efficiency by using a spiral cooling pipe that rotates with the stirrer, effectively preventing catalyst agglomeration and bubble generation, while simultaneously achieving automated temperature management, thereby improving slurry quality and production efficiency.

[0011] The above-mentioned objective of this invention is achieved through the following technical solutions: In a first aspect, the present invention provides a cooling system for the fuel cell slurry preparation process, comprising: A stirring container for holding fuel cell slurry; A stirrer is disposed inside the stirring container and is used to stir and disperse the fuel cell slurry inside the stirring container; A spiral cooling pipe is disposed inside the stirring container. The spiral cooling pipe is fixedly connected to the stirrer and moves synchronously with the stirrer. The two ends of the spiral cooling pipe are respectively connected to a cooling medium inlet pipe and a cooling medium outlet pipe. The spiral helix angle of the spiral cooling pipe is 15° to 45°. A temperature sensor is installed inside the stirring container to detect the temperature of the fuel cell slurry in real time. The controller is connected to the temperature sensor and the external cooling medium supply system respectively. The controller has a built-in slurry viscosity compensation model, which is used to compensate the temperature control parameters according to the viscosity value of the fuel cell slurry, and send cooling medium flow and / or temperature adjustment commands to the external cooling medium supply system based on the compensated control parameters. The spiral cooling tube is a hollow tubular structure with the tube body extending along a spiral path. The spiral cooling tube remains in contact with the fuel cell slurry in the stirring container during the movement of the stirrer, so as to cool the fuel cell slurry through the cooling medium flowing through the inside of the spiral cooling tube.

[0012] In the technical solution of this invention, limiting the helix angle has specific technical significance. A helix angle that is too small (less than 15°) will result in too many spiral turns in the cooling tube, increased flow resistance, and poor flow of the cooling medium; a helix angle that is too large (greater than 45°) will result in excessive spacing between adjacent spiral turns, reduced axial distribution density of the cooling tubes, and insufficient cooling area. Limiting the helix angle to the range of 15° to 45° ensures smooth flow of the cooling medium while achieving sufficient cooling area and ideal heat exchange effect.

[0013] The controller of this invention incorporates a slurry viscosity compensation model, a key feature distinguishing it from existing technologies. During fuel cell slurry preparation, the slurry viscosity dynamically changes with increasing agitation and dispersion, as well as temperature variations. These viscosity changes significantly affect the convective heat transfer coefficient: higher viscosity results in a lower convective heat transfer coefficient and a poorer cooling effect under the same cooling conditions. The viscosity compensation model of this invention dynamically compensates for temperature control parameters (such as the proportional and integral coefficients of PID control) based on the real-time detected slurry viscosity value, enabling the control system to adapt to cooling requirements under different viscosity conditions and achieve precise temperature control across the entire viscosity range.

[0014] Preferably, the stirrer includes a stirring shaft and stirring blades disposed on the stirring shaft, the spiral cooling pipe is fixedly connected to the stirring shaft by a fixed bracket, the spiral cooling pipe is sleeved on the outer periphery of the stirring shaft, and an annular gap is formed between the spiral cooling pipe and the stirring shaft.

[0015] Preferably, the spiral axis of the spiral cooling pipe coincides with the axis of the stirring shaft, the inner diameter of the spiral cooling pipe is larger than the outer diameter of the stirring shaft, and the pipe body of the spiral cooling pipe extends in a spiral with equal pitch along the axial direction of the stirring shaft.

[0016] Preferably, the spiral cooling pipe has a circular cross-section or a flat cross-section, the wall thickness of the spiral cooling pipe is 0.5mm to 3mm, and the spiral diameter of the spiral cooling pipe is 30% to 80% of the inner diameter of the stirring container.

[0017] Preferably, the cooling medium inlet pipe and cooling medium outlet pipe of the spiral cooling pipe are respectively connected to an external cooling medium supply system via a rotary joint, and the rotary joint is located at the top or bottom of the stirring container.

[0018] Preferably, the controller includes a temperature comparison module, a PID control module, and a viscosity compensation module. The temperature comparison module is used to compare the real-time temperature detected by the temperature sensor with a preset temperature range. The viscosity compensation module is used to query a preset viscosity-compensation coefficient mapping table to obtain a compensation coefficient based on the current viscosity value of the fuel cell slurry. The PID control module is used to correct the PID control parameters based on the comparison result of the temperature comparison module and the compensation coefficient, and then send a flow rate adjustment command and / or a temperature adjustment command to the external cooling medium supply system.

[0019] Preferably, the cooling system further includes an online slurry viscosity meter, which is installed inside the stirring container or connected to the circulation pipeline of the stirring container, for real-time detection of the viscosity value of the fuel cell slurry and sending the viscosity value to the controller.

[0020] Preferably, the cooling system further includes a speed sensor, which is disposed on the agitator and used to detect the real-time speed of the agitator. The controller is also connected to the speed sensor signal and is used to adjust the flow rate and / or temperature of the cooling medium according to the real-time speed and a predetermined helix angle-speed matching relationship. The helix angle-speed matching relationship is that when the helix angle increases, a higher agitation speed is matched to maintain the optimal relative flow rate between the outer wall of the cooling pipe and the slurry.

[0021] In a second aspect, the present invention provides a cooling method for the fuel cell slurry preparation process, employing the cooling system described in any one of the above claims for the fuel cell slurry preparation process, comprising the following steps: Step S1: Add the fuel cell slurry raw material to the stirring container; Step S2: Start the stirrer to stir and disperse the fuel cell slurry in the stirring container; Step S3: Cooling medium is introduced into the spiral cooling tube. The spiral cooling tube moves synchronously with the stirrer, so that the spiral cooling tube maintains dynamic contact with the fuel cell slurry during the stirring process. Step S4: The cooling medium flowing through the spiral cooling pipe exchanges heat with the fuel cell slurry to remove the heat generated by the fuel cell slurry during the stirring process, so that the temperature of the fuel cell slurry is maintained within the preset temperature range. Step S5: The temperature of the fuel cell slurry is detected in real time by a temperature sensor, and the controller performs viscosity compensation based on the detected temperature signal and the real-time viscosity value of the fuel cell slurry. Then, the controller controls the external cooling medium supply system to adjust the flow rate and / or temperature of the cooling medium to achieve closed-loop control of the fuel cell slurry temperature.

[0022] Preferably, in step S3, the flow rate of the cooling medium is 0.5 L / min to 50 L / min, and the temperature of the cooling medium is -10℃ to 25℃; in step S4, the preset temperature range is 15℃ to 30℃; in step S5, when the temperature detected by the temperature sensor is higher than the upper limit of the preset temperature range, the controller controls to increase the flow rate of the cooling medium and / or decrease the temperature of the cooling medium; when the temperature detected by the temperature sensor is lower than the lower limit of the preset temperature range, the controller controls to decrease the flow rate of the cooling medium and / or increase the temperature of the cooling medium; and the controller compensates and corrects the PID control parameters according to the real-time viscosity value of the fuel cell slurry, increasing the proportional coefficient and integral coefficient as the viscosity increases.

[0023] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects: This invention fixes a spiral cooling tube to a stirrer and makes it move synchronously with the stirrer. This ensures that the spiral cooling tube maintains dynamic contact with the slurry throughout the stirring process, significantly increasing the relative velocity and turbulence between the cooling tube and the slurry, thereby greatly improving the heat transfer coefficient and cooling efficiency. Compared to a fixed cooling tube, the spiral cooling tube in this invention, which rotates with the stirrer, continuously cuts through the slurry and disrupts the slurry boundary layer, resulting in more complete heat exchange.

[0024] This invention uses a spiral cooling pipe that is directly immersed in the slurry for cooling. Compared with the solution of setting a cooling jacket on the outside of the container, it avoids the expensive manufacturing cost of the jacketed container and reduces equipment cost. At the same time, since the cooling pipe is in direct contact with the slurry, the heat transfer path is shorter, the thermal resistance is lower, and the cooling effect is better.

[0025] In this invention, the spiral cooling pipe and the agitator are integrated into one unit, eliminating the need for special modifications to the mixing container. The mixing container can be a common container, which facilitates the metering, transportation, and handling of the slurry, simplifies the operation process, and improves production efficiency.

[0026] The spiral structure design of the spiral cooling pipe in this invention creates secondary flow and vortices as the cooling medium flows inside the pipe, further enhancing convective heat transfer and improving the heat exchange efficiency between the cooling medium and the pipe wall. In particular, limiting the spiral angle to a specific range of 15° to 45° ensures smooth flow of the cooling medium while achieving an optimal balance between cooling area and heat exchange efficiency.

[0027] This invention achieves real-time monitoring and automatic closed-loop control of slurry temperature by setting up a temperature sensor and controller. It can automatically adjust the flow rate and temperature of the cooling medium according to the changes in slurry temperature, ensuring that the slurry is always within the optimal temperature range, and effectively avoiding problems such as catalyst agglomeration and bubble generation.

[0028] This invention achieves adaptive compensation of temperature control parameters based on the real-time viscosity of the slurry by incorporating an online slurry viscosity detector and a controller with a built-in viscosity compensation model. When the slurry viscosity changes, the control system automatically adjusts the PID control parameters to ensure precise temperature control under different viscosity conditions, significantly improving the system's adaptability and robustness. This feature makes this invention particularly suitable for applications involving dynamic viscosity changes during fuel cell slurry preparation.

[0029] This invention achieves coordinated optimization control of stirring speed and cooling tube helix angle by setting a speed sensor and establishing a matching relationship between helix angle and speed. This ensures that the optimal relative flow rate between the outer wall of the cooling tube and the slurry can be maintained under different stirring speeds, further improving the cooling efficiency across the entire operating range. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the cooling system during the fuel cell slurry preparation process provided in Embodiment 1 of the present invention. Figure 2 This is a block diagram of the control module of the cooling system in the fuel cell slurry preparation process provided in Embodiment 2 of the present invention; Figure 3This is a block diagram of the temperature control logic of the cooling system in the fuel cell slurry preparation process provided in Embodiment 3 of the present invention; Figure 4 This is a block diagram of the cooling medium circulation system of the cooling system in the fuel cell slurry preparation process provided in Embodiment 4 of the present invention; Figure 5 This is a diagram of the slurry temperature distribution monitoring module of the cooling system during the fuel cell slurry preparation process provided in Embodiment 5 of the present invention; Figure 6 This is a schematic flowchart of the cooling method in the fuel cell slurry preparation process provided in Embodiment 6 of the present invention.

[0031] Reference numerals in the attached diagram: 1. Mixing container; 2. Agitator; 3. Spiral cooling pipe; 4. Temperature sensor; 5. Online slurry viscosity meter; 6. Controller; 61. Temperature comparison module; 62. Viscosity compensation module; 63. Flow regulation module; 64. PID control module; 65. Speed ​​sensor; 7. Flow meter; 8. Temperature regulating valve. Detailed Implementation

[0032] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] Example 1 like Figure 1 As shown, this embodiment provides a cooling system for the fuel cell slurry preparation process, including a stirring container 1, a stirrer 2, a spiral cooling pipe 3, a temperature sensor 4, an online slurry viscosity detector 5, and a controller 6.

[0036] The stirring container 1 is a cylindrical container with an open top, used to hold fuel cell slurry. The stirring container 1 can be made of stainless steel, glass, or polymer materials, with a smooth inner wall for easy cleaning. A removable container lid is provided at the top of the stirring container 1, with a feeding port for adding fuel cell slurry raw materials into the stirring container 1. A discharge port with a discharge valve is provided at the bottom of the stirring container 1 for discharging the slurry after preparation. A sampling port (not shown in the figure) can also be provided on the lower side wall of the stirring container 1 for sampling and testing the dispersion state and temperature of the slurry during the stirring process.

[0037] A stirrer 2 is disposed inside the stirring container 1 and is used to stir and disperse the fuel cell slurry within the container 1. The stirrer 2 includes a stirring shaft and stirring blades mounted on the shaft. The stirring shaft is vertically oriented, with its lower end extending into the interior of the stirring container 1 and its upper end extending through the container cover to the outside of the container 1. The upper end of the stirring shaft is connected to the output shaft of a drive motor via a coupling. The drive motor is fixedly mounted above the container cover and is used to drive the stirring shaft to rotate. The drive motor can be a variable frequency speed control motor to adjust the stirring speed according to process requirements.

[0038] The mixing blades are multiple; in this embodiment, there are specifically three mixing blades, which are spaced apart along the axial direction of the mixing shaft. Each mixing blade includes a hub and blades extending radially outward from the hub. The number of blades can be 2 to 6; in this embodiment, each mixing blade has 4 blades, evenly distributed around the hub. The blades can be straight, inclined, or curved; in this embodiment, inclined blades are used with an inclination angle of 30° to 60° to generate axial and radial mixing flow during mixing, improving the dispersion effect of the slurry. The axial spacing between adjacent mixing blades is 10% to 30% of the height of the mixing container 1 to ensure sufficient mixing of the slurry throughout the entire height range of the container.

[0039] A spiral cooling tube 3 is disposed inside the mixing container 1, and is fixedly connected to the stirrer 2 and moves synchronously with the stirrer 2. Specifically, the spiral cooling tube 3 is fixedly connected to the stirring shaft via a fixed bracket. Multiple fixed brackets are spaced apart along the axial direction of the stirring shaft, and each fixed bracket includes a horizontal connecting rod and a pipe clamp at the end of the horizontal connecting rod. One end of the horizontal connecting rod is fixedly connected to the outer wall of the stirring shaft, and the other end is fixedly clamped to the body of the spiral cooling tube 3 via the pipe clamp. The pipe clamp can be made of an elastic material, such as rubber or silicone, to avoid damage to the cooling tube.

[0040] A spiral cooling pipe 3 is fitted around the outer circumference of the stirring shaft, with its spiral axis coinciding with the axis of the stirring shaft. The inner diameter of the spiral cooling pipe 3 is larger than the outer diameter of the stirring shaft, creating an annular gap between the spiral cooling pipe 3 and the stirring shaft. This annular gap prevents interference between the stirring shaft and the spiral cooling pipe 3, while also facilitating the flow of the slurry within the gap, thus enhancing the mixing effect.

[0041] The spiral cooling pipe 3 is a hollow tubular structure with the pipe body extending along a spiral path. In this embodiment, the pipe body of the spiral cooling pipe 3 is a circular cross-section pipe, and the pipe body material is stainless steel (such as 304 stainless steel or 316L stainless steel), which has good corrosion resistance and thermal conductivity. The wall thickness of the spiral cooling pipe 3 is 0.5mm to 3mm, preferably 1mm to 2mm. If the wall thickness is too thin, the cooling pipe will have insufficient strength and will be easily deformed or damaged during stirring; if the wall thickness is too thick, it will increase thermal resistance and reduce heat exchange efficiency.

[0042] The helix angle of the spiral cooling tube 3 is 15° to 45°, preferably 25° to 35°. The helix angle is the angle of inclination of the helix relative to the horizontal plane, and its size directly affects the number of spiral turns, cooling area, and flow resistance within the tube. A helix angle that is too small (less than 15°) will result in too many spiral turns, increased flow resistance, poor flow of the cooling medium, and increased pumping energy consumption; a helix angle that is too large (greater than 45°) will result in excessive axial spacing between adjacent spiral coils, reduced axial distribution density of the cooling tubes, and insufficient cooling area per unit height. Limiting the helix angle to the range of 15° to 45° ensures smooth flow of the cooling medium while achieving sufficient cooling area and ideal heat exchange effect. Experiments have verified that the overall heat exchange performance is optimal when the helix angle is 30°.

[0043] The spiral diameter of the spiral cooling pipe 3 is 30% to 80% of the inner diameter of the stirring container 1, preferably 50% to 70%. If the spiral diameter is too small, the cooling pipe will be too close to the stirring shaft, resulting in insufficient cooling area; if the spiral diameter is too large, the cooling pipe will be too close to the container wall, potentially causing interference. In this embodiment, the inner diameter of the stirring container 1 is 300 mm, and the spiral diameter of the spiral cooling pipe 3 is 180 mm, approximately 60% of the inner diameter of the stirring container 1.

[0044] The spiral cooling tube 3 extends in a helical pattern with a constant pitch along the axial direction of the stirring shaft. The pitch is 20mm to 100mm, preferably 30mm to 60mm. Too small a pitch will result in too many turns of the cooling tube and increased flow resistance; too large a pitch will result in too few turns of the cooling tube and insufficient cooling area. In this embodiment, the pitch is 40mm. The spiral cooling tube 3 has 3 to 10 turns; in this embodiment, it has 6 turns.

[0045] The spiral cooling tube 3 is positioned within the axial space between adjacent stirring blades. That is, along the axial direction of the stirring shaft, the spiral cooling tube 3 and the stirring blades are arranged alternately. This arrangement ensures that the spiral cooling tube 3 is positioned between the stirring blades while they are stirring the slurry, fully utilizing the flow field generated by the stirring blades to ensure sufficient contact between the slurry and the cooling tube, thus improving heat exchange efficiency. Simultaneously, this arrangement avoids mechanical interference between the spiral cooling tube 3 and the stirring blades.

[0046] The spiral cooling pipe 3 has a cooling medium inlet pipe and a cooling medium outlet pipe connected to its two ends, respectively. Both the cooling medium inlet pipe and the cooling medium outlet pipe are flexible or rigid pipes, extending from the upper and lower ends of the spiral cooling pipe 3, respectively. In this embodiment, the cooling medium inlet pipe extends from the upper end of the spiral cooling pipe 3, and the cooling medium outlet pipe extends from the lower end of the spiral cooling pipe 3. The cooling medium inlet pipe and the cooling medium outlet pipe extend upwards along the outer wall of the stirring shaft, pass through the container lid, and connect to the external cooling medium supply system.

[0047] The cooling medium inlet pipe and cooling medium outlet pipe are connected to the external cooling medium supply system via rotary joints. The rotary joints are located at the top of the stirring vessel 1 (above the vessel lid) to ensure reliable connection between the cooling medium inlet pipe, cooling medium outlet pipe, and external piping when the stirring shaft rotates, preventing pipe entanglement. The rotary joints are mechanical seal devices known in the art, and their specific structure will not be described in detail here.

[0048] The external cooling medium supply system includes a cooling medium storage tank, a cooling pump, and a cooler. The cooling medium storage tank stores the cooling medium, which can be water, an aqueous solution of ethylene glycol, cooling oil, or other liquids with good heat capacity and fluidity. The inlet of the cooling pump is connected to the cooling medium storage tank, and its outlet is connected to the cooling medium input pipe via a pipeline. The cooler is installed on the pipeline between the cooling medium storage tank and the cooling pump, or on the cooling medium return pipeline, to cool the returning high-temperature cooling medium. The cooler can be an air-cooled cooler, a water-cooled cooler, or a compressor-cooled cooler.

[0049] Temperature sensor 4 is installed inside the stirring container 1 to monitor the temperature of the fuel cell slurry in real time. Temperature sensor 4 can be a thermocouple, resistance temperature detector (RTD), or infrared temperature sensor. In this embodiment, a platinum resistance temperature sensor (Pt100) is used, which offers high measurement accuracy and stability. The probe of temperature sensor 4 is immersed in the slurry and located in the lower middle part of the stirring container 1; this position represents the overall temperature of the slurry. Temperature sensor 4 is connected to controller 6 via a signal line, transmitting the detected temperature signal to controller 6.

[0050] An online slurry viscosity meter 5 is installed inside the stirred container 1 or connected to the circulation pipeline of the stirred container 1. It is used to detect the viscosity value of the fuel cell slurry in real time and send this viscosity value to the controller 6. The online slurry viscosity meter 5 can be an online detection device such as a rotational viscometer, a vibratory viscometer, or a capillary viscometer. In this embodiment, a vibratory online viscometer is used, which has advantages such as fast response speed, insensitivity to flow conditions, and ease of installation and maintenance, making it particularly suitable for real-time monitoring of the slurry viscosity inside the stirred container 1. The probe of the online slurry viscosity meter 5 is immersed in the slurry and located in the central region of the stirred container 1, representing the overall viscosity level of the slurry.

[0051] The controller 6 is connected to the temperature sensor 4, the online slurry viscosity analyzer 5, and the external cooling medium supply system. The controller 6 receives the temperature signal detected by the temperature sensor 4 and the viscosity signal detected by the online slurry viscosity analyzer 5. Based on the temperature signal and the slurry viscosity value, it compensates for the difference and then controls the external cooling medium supply system to adjust the flow rate and / or temperature of the cooling medium. The controller 6 can be a programmable logic controller (PLC), a microcontroller, or an industrial computer. The controller 6 has a built-in slurry viscosity compensation model, which stores a viscosity-compensation coefficient mapping table to output corresponding PID control parameter compensation coefficients based on different slurry viscosity values.

[0052] The working principle of the spiral cooling tube 3 is as follows: Driven by the cooling pump, the cooling medium flows out from the cooling medium storage tank, is cooled by the cooler, and then enters the spiral cooling tube 3 through the cooling medium inlet pipe. The cooling medium flows downward (or upward) along the tube cavity of the spiral cooling tube 3, and convective heat transfer occurs with the tube wall during the flow. The fuel cell slurry on the other side of the tube wall comes into contact with the tube wall during the stirring process, transferring heat to the tube wall and then to the cooling medium inside the tube. After absorbing heat, the temperature of the cooling medium rises, and it flows out from the other end of the spiral cooling tube 3, returning to the cooling medium storage tank through the cooling medium outlet pipe or directly entering the cooler for cooling and regeneration.

[0053] As the spiral cooling tube 3 rotates synchronously with the stirrer 2, its tube body continuously cuts the fuel cell slurry inside the stirring container 1, causing intense turbulence and mixing. This dynamic contact method has the following advantages compared to a fixed cooling tube: First, the rotating cooling tube continuously breaks down the thermal boundary layer of the slurry on the tube wall surface, allowing fresh slurry to continuously contact the tube wall, significantly improving the convective heat transfer coefficient; second, the rotating cooling tube itself plays a certain role in stirring, assisting the stirrer 2 in dispersing the slurry and improving the stirring effect; third, the rotating cooling tube makes the temperature distribution of the slurry in the container more uniform, avoiding local overheating.

[0054] The working principle of viscosity compensation control in this invention is as follows: During the fuel cell slurry preparation process, the viscosity of the slurry dynamically changes with the increase of stirring and dispersion: initially, the slurry viscosity is high; as stirring continues, agglomerates are broken up, and the viscosity gradually decreases and tends to stabilize. Changes in slurry viscosity significantly affect its convective heat transfer coefficient: the higher the viscosity, the worse the slurry flowability, the lower the convective heat transfer coefficient, and the worse the cooling effect under the same cooling conditions. Without viscosity compensation, when the slurry viscosity is high, the same cooling medium flow rate and temperature may not achieve the expected cooling effect, leading to excessive slurry temperature.

[0055] To address this issue, the controller 6 of this invention incorporates a viscosity compensation model. This model operates as follows: First, the online slurry viscosity analyzer 5 detects the slurry viscosity value in real time and sends it to the controller 6; second, the controller 6 queries a preset viscosity-compensation coefficient mapping table based on the current viscosity value to obtain the compensation coefficient corresponding to that viscosity value; then, the PID control module 64 uses this compensation coefficient to correct the proportional and integral coefficients (the higher the viscosity, the larger the compensation coefficient, and the correspondingly larger the proportional and integral coefficients); finally, based on the corrected PID parameters, the control output is calculated and sent to the cooling pump and / or cooler. Through this viscosity adaptive compensation mechanism, this invention ensures accurate temperature control under different viscosity conditions.

[0056] The controller 6 stores a preset temperature range (e.g., 15℃~30℃). When the slurry temperature detected by the temperature sensor 4 is higher than the upper limit of the preset temperature range, the controller 6 sends a control signal to the cooling pump to increase the pump speed and the flow rate of the cooling medium; simultaneously (or alternatively), the controller 6 sends a control signal to the cooler to lower the temperature of the cooling medium. When the slurry temperature drops to the preset temperature range, the controller 6 controls the cooling pump and / or cooler to return to normal operation. When the slurry temperature is lower than the lower limit of the preset temperature range, the controller 6 can reduce the flow rate of the cooling medium or increase its temperature to avoid overcooling.

[0057] This closed-loop control method enables precise control of the slurry temperature, ensuring that the slurry remains within the optimal process temperature range. This is crucial for guaranteeing the dispersion quality of the slurry and preventing catalyst agglomeration.

[0058] The cooling system provided in this embodiment for the fuel cell slurry preparation process operates as follows: First, fuel cell slurry raw materials (including catalysts, solvents, ionomers, etc.) are added to the stirring container 1 through the feed port.

[0059] Then, the drive motor is started, driving the stirring shaft to rotate. The stirring shaft drives the stirring blades and the spiral cooling pipe 3 to rotate together. The stirring blades shear, disperse, and mix the slurry, ensuring that the components are evenly dispersed.

[0060] Simultaneously, the cooling pump is started, and the cooling medium is introduced into the spiral cooling pipe 3. The cooling medium flows inside the spiral cooling pipe 3, exchanging heat with the slurry outside the pipe and carrying away the heat generated by stirring.

[0061] During the stirring and cooling process, temperature sensor 4 detects the slurry temperature in real time, online slurry viscosity meter 5 detects the slurry viscosity in real time, and controller 6 automatically adjusts the flow rate and / or temperature of the cooling medium according to the temperature and viscosity signals to achieve precise temperature control with viscosity adaptation.

[0062] Once the slurry reaches the predetermined dispersion level and temperature, stop stirring and cooling, open the discharge valve, and discharge the prepared slurry from the discharge port.

[0063] Example 2 like Figure 2 As shown, the difference between this embodiment and embodiment 1 is that the controller 6 specifically includes a temperature comparison module 61, a viscosity compensation module 62, a flow regulation module 63, and a PID control module 64.

[0064] The temperature comparison module 61 is connected to the temperature sensor 4 and is used to receive the real-time temperature signal detected by the temperature sensor 4. The temperature comparison module 61 internally stores a preset temperature range (e.g., 15℃~30℃), which can be set and adjusted according to different slurry formulations and process requirements. The temperature comparison module 61 compares the received real-time temperature value with the preset temperature range to determine whether the current slurry temperature is within the normal range.

[0065] Specifically, the temperature comparison module 61 includes an upper limit comparator and a lower limit comparator. The upper limit comparator is used to determine whether the real-time temperature is higher than the upper limit of the preset temperature range (e.g., 30°C), and the lower limit comparator is used to determine whether the real-time temperature is lower than the lower limit of the preset temperature range (e.g., 15°C). The temperature comparison module 61 generates a corresponding deviation signal based on the comparison results.

[0066] The viscosity compensation module 62 is connected to the online slurry viscosity detector 5 to receive the real-time viscosity value of the slurry. Internally, the viscosity compensation module 62 stores a viscosity-compensation coefficient mapping table, obtained through experimental calibration, reflecting the PID parameter compensation coefficients corresponding to different viscosity values. The viscosity compensation module 62 queries the mapping table based on the current viscosity value, obtains the corresponding compensation coefficient, and sends this coefficient to the PID control module 64. Generally, the higher the viscosity, the larger the compensation coefficient, to compensate for the decrease in convective heat transfer coefficient under high viscosity conditions.

[0067] The PID control module 64 is signal-connected to the temperature comparison module 61 and the viscosity compensation module 62, and is used to receive the temperature deviation signal output by the temperature comparison module 61 and the compensation coefficient output by the viscosity compensation module 62. The PID control module 64 calculates the basic control quantity based on the temperature deviation signal, and then corrects the basic control quantity using the compensation coefficient to obtain the final control output quantity. Specifically, the PID control module 64 calculates according to the following formula: P_correction = P_base × K_compensation; I_correction = I_base × K_compensation; Wherein, P_base is the uncompensated proportional coefficient, I_base is the uncompensated integral coefficient, and K_compensation is the compensation coefficient output by viscosity compensation module 62 (K_compensation ≥ 1).

[0068] The flow regulation module 63 is signal-connected to the PID control module 64 and is used to send flow regulation commands and / or temperature regulation commands to the external cooling medium supply system according to the control quantity output by the PID control module 64. When the control quantity indicates that the cooling effect needs to be enhanced, the flow regulation module 63 generates a flow increase command and / or a temperature decrease command and sends it to the cooling pump and / or cooler; when the control quantity indicates that the cooling effect needs to be weakened, the flow regulation module 63 generates a flow decrease command and / or a temperature increase command; when the control quantity indicates that the status quo should be maintained, the flow regulation module 63 generates a hold command.

[0069] This embodiment divides the controller 6 into a temperature comparison module 61, a viscosity compensation module 62, a PID control module 64, and a flow regulation module 63, thereby realizing the modularization of functions such as temperature detection, viscosity compensation, PID calculation, and flow regulation, which facilitates the design, debugging, and maintenance of the system.

[0070] The other structures and working principles of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0071] Example 3 like Figure 3 As shown, the difference between this embodiment and embodiment 1 is that the controller 6 also includes a speed sensor 65, and the controller 6 has a built-in helix angle-speed matching relationship.

[0072] A speed sensor 65 is mounted on the stirrer 2 to detect the real-time speed of the stirrer 2. The speed sensor 65 can be a Hall sensor, photoelectric encoder, or magnetoelectric speed sensor 65, etc. In this embodiment, a Hall speed sensor 65 is used, which has the advantages of non-contact measurement, fast response speed, and high reliability. The speed sensor 65 is connected to the controller 6 via a signal line, sending the detected speed signal to the controller 6.

[0073] The controller 6 also stores a predetermined helix angle-speed matching relationship. This matching relationship is established based on fluid mechanics principles and experimental data. Its core idea is that as the helix angle increases, the helical inclination of the cooling tube increases, and the relative motion trajectory between the outer wall of the cooling tube and the slurry changes. To maintain optimal relative flow rate and heat exchange effect, a higher stirring speed is required. Specifically, the helix angle-speed matching relationship can be expressed as: n_optimal = n_base × f(α); Where n_optimal is the optimal stirring speed, n_base is the base stirring speed, α is the helix angle, and f(α) is the matching function that increases with the increase of the helix angle.

[0074] The controller 6 determines whether the current speed is within the optimal matching range based on the real-time speed detected by the speed sensor 65 and the predetermined helix angle-speed matching relationship. When the actual speed deviates from the optimal matching speed, the controller 6 sends a speed adjustment command to the drive motor to adjust the stirring speed to the optimal matching value; at the same time, the controller 6 adjusts the flow rate and / or temperature of the cooling medium accordingly based on the speed change to ensure that an ideal cooling effect can be obtained under different speed conditions.

[0075] By employing this spiral angle-speed coordinated control method, the present invention can maintain the optimal relative flow rate between the outer wall of the cooling tube and the slurry across the entire speed range, thereby ensuring stable and efficient cooling performance under different stirring conditions.

[0076] The temperature control logic in this embodiment is as follows: First, the temperature sensor 4 detects the slurry temperature in real time and sends the temperature signal to the temperature comparison module 61.

[0077] The temperature comparison module 61 calculates the deviation between the real-time temperature and the preset temperature target value (e.g., 25°C).

[0078] Meanwhile, the speed sensor 65 detects the real-time speed of the agitator 2, and the viscosity sensor detects the real-time viscosity of the slurry.

[0079] The PID control module 64 calculates the control output based on the temperature deviation value and the viscosity compensation coefficient.

[0080] At the same time, the controller 6 determines whether the current speed matches the helix angle based on the feedback from the speed sensor 65. If there is a deviation, a speed adjustment command is issued.

[0081] The flow regulation module 63 generates corresponding control commands based on the control output and sends them to the cooling pump and / or cooler.

[0082] The cooling pump and / or cooler regulate the flow rate and / or temperature of the cooling medium according to control commands.

[0083] The slurry temperature changes accordingly, and the new temperature value is detected again by temperature sensor 4, forming a closed-loop control circuit.

[0084] The other structures and working principles of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0085] Example 4 like Figure 4 As shown, the difference between this embodiment and embodiment 1 is that the external cooling medium supply system also includes a flow meter 7 and a temperature regulating valve 8.

[0086] Flow meter 7 is installed on the cooling medium inlet pipe or cooling medium outlet pipe to detect the real-time flow rate of the cooling medium. Flow meter 7 can be a turbine flow meter, electromagnetic flow meter, or ultrasonic flow meter, etc. Flow meter 7 is connected to controller 6 and sends the detected flow signal to controller 6. Controller 6 can perform closed-loop control of the cooling pump speed based on the flow signal fed back by flow meter 7 to ensure that the flow rate of the cooling medium accurately reaches the set value.

[0087] Temperature regulating valve 8 is installed on the inlet or outlet pipeline of the cooler to regulate the temperature of the cooler. Temperature regulating valve 8 is either electrically or pneumatically operated, and its opening is controlled by controller 6. When it is necessary to lower the temperature of the cooler, controller 6 increases the opening of temperature regulating valve 8, thereby increasing the cooling capacity of the cooler; when it is necessary to raise the temperature of the cooler, controller 6 decreases the opening of temperature regulating valve 8, thereby decreasing the cooling capacity of the cooler.

[0088] In this embodiment, the specific workflow of the cooling medium circulation system is as follows: The cooling medium in the cooling medium storage tank is pumped out by a cooling pump, cooled by a cooler, and then enters the spiral cooling pipe 3 through the cooling medium inlet pipe. A flow meter 7 is installed on the cooling medium inlet pipe to detect the flow rate of the cooling medium.

[0089] After the cooling medium exchanges heat with the slurry inside the spiral cooling pipe 3, its temperature rises and it returns to the cooling medium storage tank through the cooling medium output pipe or directly enters the cooler for regeneration cooling.

[0090] The controller 6 controls the speed of the cooling pump and the opening of the temperature regulating valve 8 based on the slurry temperature detected by the temperature sensor 4, the viscosity value detected by the online slurry viscosity detector 5, and the speed value detected by the speed sensor 65, thereby achieving dual regulation of the flow rate and temperature of the cooling medium.

[0091] This dual-regulation method offers greater control flexibility and precision. For example, when the slurry temperature rises slightly, the flow rate of the cooling medium can be increased without changing the temperature; when the slurry temperature rises significantly, the flow rate can be increased and the temperature decreased simultaneously to achieve rapid cooling.

[0092] The other structures and working principles of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0093] Example 5 like Figure 5 As shown, the difference between this embodiment and embodiment 1 is that there are multiple temperature sensors 4, which are distributed along the height direction and / or radial direction of the mixing container 1 to detect the temperature of the slurry at different positions inside the mixing container 1.

[0094] Specifically, in this embodiment, a first temperature sensor 4, a second temperature sensor 4, and a third temperature sensor 4 are provided. The first temperature sensor 4 is located in the upper region of the mixing container 1 and is used to detect the temperature of the upper part of the slurry; the second temperature sensor 4 is located in the middle region of the mixing container 1 and is used to detect the temperature of the middle part of the slurry; the third temperature sensor 4 is located in the lower region of the mixing container 1 and is used to detect the temperature of the lower part of the slurry.

[0095] Multiple temperature sensors 4 are connected to the controller 6, respectively, and send the temperature signals they detect to the controller 6. The controller 6 can perform comprehensive processing on the multiple temperature signals, such as calculating the average temperature and the maximum temperature difference, and control the flow rate and / or temperature of the cooling medium based on the comprehensive processing results.

[0096] This embodiment also includes a data acquisition module and a display module. The data acquisition module is connected to multiple temperature sensors 4 and is used to acquire temperature data detected by each temperature sensor 4. The data acquisition module can be a data acquisition card (DAQ) or an integrated data acquisition module, and has multi-channel analog input functionality.

[0097] The display module is connected to the data acquisition module and is used to display the temperature information of the fuel cell slurry and the operating status information of the cooling system in real time. The display module can use an LCD screen or a touch screen to intuitively display temperature data and system status in the form of numbers, curves, charts, etc.

[0098] In this embodiment, the display module can simultaneously display the following information: (1) Real-time temperature values ​​detected by each temperature sensor 4; (2) Average temperature of the slurry; (3) The maximum temperature difference inside the slurry; (4) Trend curve of temperature change over time; (5) The flow rate and temperature of the cooling medium; (6) Real-time viscosity value of the slurry; (7) Real-time rotation speed of stirrer 2; (8) The operating status of the cooling system (normal, alarm, etc.).

[0099] By arranging multiple temperature sensors 4 and setting up a data acquisition and display module, operators can gain a comprehensive understanding of the temperature distribution of the slurry during the mixing process, promptly detect temperature anomalies, and intervene. Simultaneously, the temperature distribution data can also be used to optimize the mixing process and cooling strategy; for example, by analyzing the uniformity of the temperature distribution, the mixing speed or cooling pipe layout can be adjusted.

[0100] The other structures and working principles of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0101] Example 6 like Figure 6 As shown, this embodiment provides a cooling method during the fuel cell slurry preparation process. This method employs the cooling system described in any of the above embodiments during the fuel cell slurry preparation process. The method includes the following steps: Step S1: Adding materials Add the fuel cell slurry raw material to the stirring container 1.

[0102] Specifically, open the feeding port on the container lid and add the solvent, catalyst, ionomer, and other raw materials to the mixing container 1 in sequence according to the predetermined formula ratio. The order of addition can be determined according to process requirements; usually, the solvent is added first, followed by the catalyst and ionomer. During the addition process, the stirrer 2 can be started for low-speed pre-stirring to allow the components to mix initially. After the addition is complete, close the feeding port.

[0103] Step S2: Stirring Step Start stirrer 2 to stir and disperse the fuel cell slurry in stirring container 1.

[0104] Specifically, the drive motor is started, driving the stirring shaft to rotate, which in turn drives the stirring blades to rotate. The stirring blades shear, disperse, and mix the slurry. The stirring speed is determined based on the slurry's viscosity, solid content, and dispersion requirements, typically ranging from 500 rpm to 5000 rpm. For high-viscosity slurries, a lower speed (e.g., 500 rpm to 1500 rpm) can be used; for low-viscosity slurries, a higher speed (e.g., 2000 rpm to 5000 rpm) can be used. The stirring time is determined based on the degree of dispersion of the slurry, typically ranging from 30 minutes to 120 minutes.

[0105] During the stirring process, the shear force generated by the stirring blades breaks up the catalyst agglomerates, ensuring that the catalyst particles are evenly dispersed in the solvent. Simultaneously, the mechanical energy generated by stirring is converted into heat energy, causing the slurry temperature to gradually rise.

[0106] Step S3: Introduce cooling medium Cooling medium is introduced into the spiral cooling tube 3. The spiral cooling tube 3 moves synchronously with the stirrer 2, so that the spiral cooling tube 3 maintains dynamic contact with the fuel cell slurry during the stirring process.

[0107] Specifically, at the same time as or shortly after the start of stirring, the cooling pump is activated to pump the cooling medium from the cooling medium storage tank. After being cooled by the cooler, the medium is sent into the spiral cooling pipe 3 through the cooling medium inlet pipe. The cooling medium flows inside the spiral cooling pipe 3 from one end to the other, and then flows out through the cooling medium outlet pipe.

[0108] The flow rate of the cooling medium is 0.5 L / min to 50 L / min, preferably 2 L / min to 20 L / min. Too low a flow rate will result in insufficient cooling; too high a flow rate will increase energy consumption and equipment load. The temperature of the cooling medium is -10℃ to 25℃, preferably 0℃ to 15℃. The temperature of the cooling medium can be determined based on the preset temperature requirements of the slurry and the heat generated by stirring. For slurries that are particularly sensitive to temperature, a lower temperature cooling medium can be used.

[0109] The spiral cooling tube 3 rotates synchronously with the stirring shaft. During the rotation, the tube body of the spiral cooling tube 3 continuously contacts and cuts the slurry, causing strong relative motion and turbulence between the slurry and the cooling tube, which enhances the heat transfer process.

[0110] Step S4: Heat exchange step The cooling medium flowing through the spiral cooling pipe 3 exchanges heat with the fuel cell slurry to remove the heat generated during the stirring process, thus maintaining the temperature of the fuel cell slurry within a preset temperature range.

[0111] Specifically, the heat of the slurry is transferred to the cooling medium inside the spiral cooling pipe 3 through the pipe wall. After absorbing the heat, the temperature of the cooling medium rises and flows out of the cooling pipe carrying the heat. By continuously introducing the cooling medium, the heat generated by stirring is continuously carried away, and the temperature of the slurry is controlled within the preset temperature range.

[0112] The preset temperature range is 15℃~30℃, preferably 20℃~25℃. This temperature range is the optimal temperature range for fuel cell slurry preparation. Within this temperature range, the activity of the catalyst can be maintained, and agglomeration and bubbles will not occur due to excessive temperature.

[0113] Step S5: Closed-loop control steps Temperature sensor 4 detects the temperature of fuel cell slurry in real time, and online slurry viscosity meter 5 detects the viscosity of fuel cell slurry in real time. Controller 6 then controls the external cooling medium supply system to adjust the flow rate and / or temperature of the cooling medium based on the detected temperature signal and the real-time viscosity value after viscosity compensation, thereby achieving closed-loop control of the fuel cell slurry temperature.

[0114] Specifically, temperature sensor 4 sends the detected real-time temperature signal to controller 6. Online slurry viscosity analyzer 5 sends the detected real-time viscosity signal to controller 6. Temperature comparison module 61 within controller 6 compares the real-time temperature with a preset temperature range. Viscosity compensation module 62 within controller 6 queries a viscosity-compensation coefficient mapping table based on the real-time viscosity value to obtain the compensation coefficient. PID control module 64 uses the compensation coefficient to correct the PID parameters. When the real-time temperature is higher than the upper limit of the preset temperature range, controller 6 controls to increase the flow rate of the cooling medium and / or decrease the temperature of the cooling medium. When the real-time temperature is lower than the lower limit of the preset temperature range, controller 6 controls to decrease the flow rate of the cooling medium and / or increase the temperature of the cooling medium. When the real-time temperature is within the preset temperature range, controller 6 maintains the current cooling medium parameters. Higher viscosity results in a larger compensation coefficient, and the proportional and integral coefficients of the PID control increase accordingly to enhance the response capability of the control system and compensate for the reduction in heat transfer efficiency under high viscosity conditions.

[0115] This viscosity-adaptive closed-loop control method enables precise control of slurry temperature, ensuring that the slurry is always within the optimal process temperature range.

[0116] After mixing and cooling are complete, stop the drive motor and cooling pump, open the discharge valve, and discharge the prepared slurry from the discharge port to proceed to the subsequent coating process.

[0117] Step S6: Cleaning Steps (Optional) After the slurry is discharged, cleaning solvent can be added to the mixing container 1, and the agitator 2 and spiral cooling pipe 3 can be started for cleaning. The cleaning solvent can recover the paint residue adhering to the surface of the agitator 2 and spiral cooling pipe 3, and then the cleaning waste liquid is discharged. This step helps to keep the equipment clean and prevent cross-contamination between different batches of slurry.

[0118] The specific embodiments of the present invention have been described in detail above. It should be noted that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention without departing from its principles. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0119] The cooling system and method for fuel cell slurry preparation provided by this invention can be widely applied in the preparation of fuel cell MEA coatings. This invention achieves efficient in-situ cooling by installing a spiral cooling pipe 3 fixedly connected to a stirrer 2 within a stirring container 1, allowing the cooling pipe to move synchronously with the stirrer 2 and dynamically contact the slurry during stirring. Simultaneously, through the cooperation of a temperature sensor 4, an online slurry viscosity analyzer 5, and a controller 6, viscosity-adaptive closed-loop precise temperature control is achieved. This invention further optimizes cooling performance across the entire operating range by limiting the spiral helix angle to a specific range and combining it with rotational speed control. This invention has a simple structure, low cost, and convenient operation, effectively controlling slurry temperature, preventing catalyst agglomeration and bubble generation, improving slurry quality and fuel cell power generation performance, and possesses significant industrial practical value and broad application prospects.

[0120] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A cooling system for the fuel cell slurry preparation process, characterized in that, include: A stirring container (1) is used to contain fuel cell slurry; A stirrer (2) is disposed inside the stirring container (1) and is used to stir and disperse the fuel cell slurry inside the stirring container (1); Spiral cooling pipe (3) is installed inside the stirring container (1). The spiral cooling pipe (3) is fixedly connected to the stirrer (2) and moves synchronously with the stirrer (2). The two ends of the spiral cooling pipe (3) are respectively connected to the cooling medium input pipe and the cooling medium output pipe. The spiral angle of the spiral cooling pipe (3) is 15° to 45°. Temperature sensor (4), which is installed inside the stirring container (1), is used to detect the temperature of the fuel cell slurry in real time; The controller (6) is connected to the temperature sensor (4) and the external cooling medium supply system respectively. The controller (6) has a built-in slurry viscosity compensation model, which is used to compensate the temperature control parameters according to the viscosity value of the fuel cell slurry, and send cooling medium flow and / or temperature adjustment commands to the external cooling medium supply system based on the compensated control parameters. The spiral cooling pipe (3) is a hollow tubular structure with the pipe body extending along a spiral path. The spiral cooling pipe (3) remains in contact with the fuel cell slurry in the stirring container (1) during the operation of the stirrer (2) so as to cool the fuel cell slurry through the cooling medium flowing through the interior of the spiral cooling pipe (3).

2. The cooling system for fuel cell slurry preparation according to claim 1, characterized in that, The stirrer (2) includes a stirring shaft and stirring blades disposed on the stirring shaft. The spiral cooling pipe (3) is fixedly connected to the stirring shaft through a fixed bracket. The spiral cooling pipe (3) is sleeved on the outer periphery of the stirring shaft, and an annular gap is formed between the spiral cooling pipe (3) and the stirring shaft.

3. The cooling system for fuel cell slurry preparation according to claim 2, characterized in that, The spiral axis of the spiral cooling pipe (3) coincides with the axis of the stirring shaft. The inner diameter of the spiral cooling pipe (3) is larger than the outer diameter of the stirring shaft. The pipe body of the spiral cooling pipe (3) extends in a spiral with equal pitch along the axial direction of the stirring shaft.

4. The cooling system for fuel cell slurry preparation according to claim 2, characterized in that, The spiral cooling pipe (3) has a circular cross-section or a flat cross-section. The wall thickness of the spiral cooling pipe (3) is 0.5 mm to 3 mm. The spiral diameter of the spiral cooling pipe (3) is 30% to 80% of the inner diameter of the stirring container (1).

5. A cooling system for fuel cell slurry preparation according to claim 1, characterized in that, The cooling medium inlet pipe and cooling medium outlet pipe of the spiral cooling pipe (3) are respectively connected to the external cooling medium supply system through a rotary joint, which is located at the top or bottom of the stirring container (1).

6. A cooling system for fuel cell slurry preparation according to claim 1, characterized in that, The controller (6) includes a temperature comparison module (61) and a flow regulation module (63). The temperature comparison module (61) is used to compare the real-time temperature detected by the temperature sensor (4) with a preset temperature range. The flow regulation module (63) is used to send a flow regulation command and / or a temperature regulation command to the external cooling medium supply system according to the comparison result of the temperature comparison module (61).

7. A cooling system for fuel cell slurry preparation according to claim 2, characterized in that, The stirring blades are multiple, and the multiple stirring blades are spaced apart along the axial direction of the stirring shaft. The spiral tube body of the spiral cooling pipe (3) is disposed in the axial space between adjacent stirring blades.

8. A cooling system for fuel cell slurry preparation according to claim 1, characterized in that, It also includes a speed sensor (65), which is disposed on the stirrer (2) for detecting the real-time speed of the stirrer (2). The controller (6) is also connected to the speed sensor (65) for adjusting the flow rate and / or temperature of the cooling medium according to the real-time speed and a predetermined helix angle-speed matching relationship. The helix angle-speed matching relationship is: when the helix angle increases, a higher stirring speed is matched to maintain the optimal relative flow rate between the outer wall of the cooling pipe and the slurry.

9. A cooling method during the preparation of fuel cell slurry, characterized in that, A cooling system for a fuel cell slurry preparation process as described in any one of claims 1 to 8 includes the following steps: Step S1: Add the fuel cell slurry raw material to the stirring container (1); Step S2: Start the stirrer (2) to stir and disperse the fuel cell slurry in the stirring container (1); Step S3: Cooling medium is introduced into the spiral cooling tube (3). The spiral cooling tube (3) moves synchronously with the stirrer (2) so that the spiral cooling tube (3) maintains dynamic contact with the fuel cell slurry during the stirring process. Step S4: The cooling medium flowing through the spiral cooling pipe (3) exchanges heat with the fuel cell slurry to remove the heat generated by the fuel cell slurry during the stirring process, so that the temperature of the fuel cell slurry is maintained within the preset temperature range. Step S5: The temperature of the fuel cell slurry is detected in real time by the temperature sensor (4), and the external cooling medium supply system is controlled by the controller (6) to adjust the flow rate and / or temperature of the cooling medium after viscosity compensation based on the detected temperature signal and the real-time viscosity value of the fuel cell slurry, so as to realize closed-loop control of the temperature of the fuel cell slurry.

10. A cooling method for the fuel cell slurry preparation process according to claim 9, characterized in that, In step S3, the flow rate of the cooling medium is 0.5L / min to 50L / min, and the temperature of the cooling medium is -10℃ to 25℃; in step S4, the preset temperature range is 15℃ to 30℃; in step S5, when the temperature detected by the temperature sensor (4) is higher than the upper limit of the preset temperature range, the controller (6) controls to increase the flow rate of the cooling medium and / or decrease the temperature of the cooling medium; when the temperature detected by the temperature sensor (4) is lower than the lower limit of the preset temperature range, the controller (6) controls to decrease the flow rate of the cooling medium and / or increase the temperature of the cooling medium. Furthermore, the controller (6) compensates and corrects the PID control parameters based on the real-time viscosity value of the fuel cell slurry. The higher the viscosity, the greater the proportional coefficient and integral coefficient are.

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