A method for inhibiting temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamlined flow channel

Abstract

This invention relates to the field of hydrogen energy engineering and thermal management technology, and particularly to a method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamlined flow channel. The technical solution includes: constructing a temperature-sensitive active inner wall layer on the inner wall of the biomimetic streamlined flow channel and encapsulating phase change microcapsules; the micropore openings are provided with temperature-sensitive sealing layers; when the local temperature reaches a preset trigger threshold, the micropores open, the microcapsules release into the mainstream hydrogen gas and rupture, and the phase change absorbs the heat of hydrogen compression and frictional heat to suppress temperature rise; when the temperature is below a second preset threshold, the unreleased microcapsules undergo a reverse phase change to release heat, suppressing temperature drop and achieving local adaptive thermal regulation. This invention achieves local adaptive release and phase change temperature regulation of phase change microcapsules through a biomimetic sweat gland micropore network controlled by a temperature-sensitive sealing layer. During hydrogen charging and discharging, it absorbs the heat of hydrogen compression and frictional heat and compensates for expansion and cooling, thereby achieving efficient and cyclic transient temperature regulation within the flow channel and improving system reliability without increasing flow resistance.

Description

Technical Field

[0001] This invention relates to the field of hydrogen energy engineering and thermal management technology, and in particular to a method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamlined flow channel. Background Technology

[0002] Hydrogen energy, as a clean and efficient secondary energy source, has broad application prospects in transportation, energy storage, and industry. High-pressure hydrogen storage is currently the core technology for hydrogen supply systems in fuel cell vehicles. During high-pressure rapid hydrogen charging, hydrogen gas is compressed and flows rapidly into the hydrogen storage container and pipeline channels in a short period of time. Due to the heat of gas compression and frictional heat of the walls, the local temperature of the channels can rapidly rise to above 85°C, or even exceed 100°C. This drastic temperature rise accelerates the aging of sealing materials, reduces the hydrogen embrittlement resistance of metal materials, and poses safety hazards. At the same time, during hydrogen release, the rapid expansion and heat absorption of hydrogen gas can cause the local temperature of the channels to plummet to below -40°C, causing problems such as pipeline frosting and low-temperature embrittlement of seals, seriously affecting the system's cycle life and reliability.

[0003] To address the thermal effects during the hydrogen charging and discharging process, existing technologies mainly employ the following solutions: One approach is to force-cool the hydrogen charging pipeline and hydrogen storage container through an external water-cooling or air-cooling system. However, this method has drawbacks such as delayed thermal response, high energy consumption, and uneven cooling, and it cannot provide heating during the hydrogen release process. Secondly, a phase change material coating is applied to the inner wall of the flow channel to absorb or release heat using the latent heat of phase change. However, conventional coatings cover the entire surface, which can lead to unnecessary consumption of phase change material in non-hotspot areas. Furthermore, direct contact between the coating and hydrogen can easily cause swelling or peeling. Third, designing fins or microchannels to expand the heat exchange surface, but such structures will increase flow resistance and occupy valuable flow channel space, and may also cause stress concentration problems under high pressure. Fourth, external temperature control strategies (such as adjusting the refueling rate) are adopted, but this method is limited by hydrogen refueling protocols and user experience, and the adjustment range is limited, so it cannot fundamentally eliminate local heat peaks.

[0004] Most existing technologies are designed for overall temperature control, but they are not effective in suppressing local temperature peaks that are not uniformly distributed along the flow path.

[0005] To address this problem, we propose a high-pressure hydrogen charging and discharging biomimetic streamlined flow channel temperature rise suppression method. Summary of the Invention

[0006] The purpose of this invention is to address the problems existing in the background art by proposing a method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamlined flow channel.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamlined flow channel, comprising the following steps: S1. A temperature-sensitive active inner wall layer is constructed on the inner wall of the biomimetic streamlined flow channel body used for high-pressure hydrogen charging and discharging. The temperature-sensitive active inner wall layer is embedded with a biomimetic sweat gland micropore network. The biomimetic sweat gland micropores are encapsulated with phase change microcapsules, and the microcapsules in the micropores are in a capillary confinement and sealing state. A temperature-sensitive sealing layer is provided at the opening of the biomimetic sweat gland micropores. The temperature-sensitive sealing layer closes the micropores when the temperature is below a preset trigger threshold and opens the micropores when the preset trigger threshold is reached or exceeded. S2. During the high-pressure hydrogen charging and discharging process, the temperature along the flow path is continuously monitored, and a local temperature field distribution is formed. S3. When the local temperature of any region reaches or exceeds the preset trigger threshold, the temperature-sensitive sealing layer of the biomimetic sweat gland micropores in the region is opened, so that the microcapsule is directionally released from the micropores into the mainstream hydrogen gas under the coupling effect of capillary driving force and mainstream shear force. S4. When the stress generated by at least one of the flow shearing and particle collision in the mainstream hydrogen reaches its shell rupture threshold, the microcapsule ruptures and releases the internal phase change material. The phase change material undergoes a phase change during the flow and absorbs at least one of the hydrogen compression heat and friction heat that cause local temperature rise, thereby forming a transient heat absorption zone in the local area to suppress the temperature rise peak. S5. During the hydrogen release process, when the local temperature is lower than the second preset threshold, the phase change material in the microcapsules that have not yet been released in the biomimetic sweat gland micropores undergoes a reverse phase change and releases heat to suppress the sudden drop in temperature caused by gas expansion. The second preset threshold is lower than the preset trigger threshold. The opening of the biomimetic sweat gland micropores, the release of microcapsules, and the phase change endothermic process are spatially locally adaptively distributed.

[0008] Furthermore, the biomimetic sweat gland micropores are distributed in a gradient along the flow channel axis, with the distribution density gradually increasing with the flow direction. The distribution density in the curved area is higher than that in the straight area, so that the temperature rise sensitive area has a higher release response capability.

[0009] Furthermore, the biomimetic sweat gland micropores have a pore size of 5–50 μm and form a radially tapering structure from large to small to create a capillary pressure gradient, which allows the microcapsules to be stably sealed in the untriggered state and to have unidirectional release characteristics after triggering.

[0010] Furthermore, the temperature-sensitive sealing layer is a temperature-sensitive polymer sealing layer. When the temperature is below the trigger threshold, the sealing layer is in a swollen and closed state. When the temperature reaches or exceeds the trigger threshold, at least one of the following changes occurs: volume shrinkage and phase transition, in order to reduce the sealing effect on the micropores and open the micropores.

[0011] Furthermore, the microcapsule has a core-shell structure, and the fracture strength of its shell material is matched with the shear stress of hydrogen flow, so that it meets the conditions of not rupturing in the micropores and controlling rupture in the main flow.

[0012] Furthermore, the phase change temperature of the phase change material is set within the range of ±5°C of the preset trigger threshold, so that the phase change and heat absorption occur immediately after the microcapsules are released, thereby shortening the thermal response hysteresis time.

[0013] Furthermore, the flow channel body is a biomimetic streamlined structure, including a pressure-reducing inlet zone and a flow-equalizing transition zone arranged sequentially along the flow direction. The pressure-reducing inlet zone is a streamlined diffuser structure with a gradually increasing cross-sectional area along the flow direction, and the flow-equalizing transition zone is a straight flow channel with a uniform cross-sectional area. The structure is used to reduce flow separation and local turbulence intensity in order to maintain the uniform dispersion of microcapsules in the mainstream.

[0014] Furthermore, the temperature monitoring is achieved through an embedded distributed sensing unit. The temperature signal output by the sensing unit is used to dynamically adjust the external hydrogen charging and discharging rate and / or control the start and stop of the auxiliary cooling device, so as to coordinate with the phase change endothermic process of the microcapsule and enhance the temperature regulation effect.

[0015] Furthermore, the temperature-sensitive active inner wall layer is a composite structure of a porous matrix and a functional coating. The porous matrix is ​​used to support the microporous network, and the functional coating is used to improve the pressure resistance and impermeability in a hydrogen environment. The total amount of phase change microcapsules encapsulated in the biomimetic sweat gland microporous network is sufficient to support at least 100 complete hydrogen charge-discharge cycles, and the temperature-sensitive sealing layer can be reversibly opened and closed during temperature cycling.

[0016] Furthermore, the flow channel body is used in at least one of the hydrogen refueling gun flow channel, the inlet and outlet gas channel of the hydrogen storage container, and the pipeline of the on-board hydrogen supply system.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: By constructing a biomimetic sweat gland micropore network on the inner wall and setting a temperature-sensitive sealing layer, the micropores in the area will only open and release phase change microcapsules when the local temperature reaches or exceeds the preset trigger threshold. The release, rupture and phase change heat absorption process of the microcapsules are locally adaptively distributed in space, realizing precise thermal control of "where it is overheated, it responds", avoiding the ineffective consumption of traditional full-surface coating methods and significantly improving the utilization efficiency of phase change materials. Phase change microcapsules undergo a positive phase change and absorb heat at high hydrogen filling temperatures, suppressing the peak temperature rise. They also undergo a reverse phase change and release heat at low hydrogen desorption temperatures, suppressing the sudden temperature drop caused by gas expansion. A single microcapsule system can play both endothermic and exothermic roles during hydrogen filling and desorption, solving the problems of separating cooling and heating functions and complex equipment in existing technologies. The phase change temperature of the phase change material is precisely designed within the range of ±5℃ of the preset trigger threshold. Once the microcapsules are released into the mainstream, they break down rapidly under the action of flow shear and collision and immediately undergo phase change and heat absorption. The thermal response lag time is extremely short. At the same time, the temperature-sensitive sealing layer undergoes volume shrinkage and phase transformation when the threshold is exceeded, resulting in a fast opening response speed and effective response to transient thermal pulses during hydrogen charging. The biomimetic sweat gland micropores adopt a tapered structure, and achieve sealed and controlled release through the synergistic effect of pore size structure and sealing layer. This facilitates the directional release of microcapsules and inhibits backflow. The strength of the microcapsule shell is designed to match the mainstream shear stress, ensuring that it does not rupture inside the micropores and can rupture in a controlled manner in the mainstream. The temperature-sensitive sealing layer has reversible swelling and contraction characteristics, which can be repeatedly opened and closed in multiple temperature cycles. The total amount of microcapsules encapsulated in the inner wall layer is sufficient to support multiple complete hydrogen charge-discharge cycles, and has excellent long-term durability. The flow channel adopts a biomimetic streamlined structure, including a pressure-reducing inlet zone and a flow-equalizing transition zone, which can effectively reduce flow separation and local turbulence intensity, providing a stable flow environment for the released microcapsules, allowing them to maintain a uniform dispersion in the mainstream hydrogen gas, thereby forming a continuous and uniform transient heat absorption zone, further improving the overall temperature rise suppression effect. The embedded distributed sensing unit monitors the temperature field along the process in real time, and its feedback signal can be used to dynamically adjust the external hydrogen charging and discharging rate or start and stop the auxiliary cooling device. This external active control works in conjunction with the internal passive phase change endothermic process, and makes control decisions based on preset temperature thresholds and change rates: when the heat absorption capacity of the microcapsules is close to saturation, the external system can quickly reduce the hydrogen charging rate to prevent overheating; when the temperature is effectively suppressed, a high flow rate can be maintained for refueling. This strategy of combining internal and external control not only ensures the safety boundary, but also maximizes the hydrogen charging efficiency. By effectively suppressing the temperature rise during hydrogen charging, the risks of thermal degradation of seals and hydrogen embrittlement of materials can be avoided, reducing the risk of fire or explosion. By suppressing the temperature drop during hydrogen release, low-temperature brittle fracture and frosting blockage can be prevented. These two aspects work together to significantly extend the service life of key components of the hydrogen supply system, reduce the total life cycle maintenance cost, and promote the large-scale application of high-pressure hydrogen energy technology. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 like Figure 1 As shown, this embodiment provides a method for suppressing temperature rise in a biomimetic streamlined flow channel during high-pressure hydrogen charging and discharging. This method is particularly suitable for hydrogen refueling nozzle flow channels, inlet and outlet gas channels of hydrogen storage containers, or pipelines of on-board hydrogen supply systems, in order to solve the problem of severe temperature fluctuations caused by compression heat and frictional heat during rapid charging and discharging of high-pressure hydrogen, while also taking into account the temperature changes caused by gas expansion.

[0021] S1. Construct a biomimetic streamlined flow channel body with a temperature-sensitive active inner wall layer. First, a flow channel body is fabricated with a biomimetic streamlined profile on its inner wall. This profile is optimized based on fluid dynamics to reduce flow resistance and minimize eddy current generation. A temperature-sensitive active inner wall layer is then constructed on the inner wall of this flow channel body. This inner wall layer is a composite structure of a porous matrix (e.g., sintered metal powder or porous ceramic) and a functional coating (e.g., a dense diamond-like carbon or graphene composite coating). The porous matrix supports the subsequent microporous network, and its three-dimensionally interconnected open structure ensures storage space and release channels for the microcapsules. The functional coating improves pressure resistance and impermeability under high-pressure hydrogen conditions while reducing the friction coefficient between hydrogen and the wall surface, thus reducing frictional heat generation at its source.

[0022] Within this temperature-sensitive active inner wall layer, a network of biomimetic sweat gland micropores is embedded using laser micro-drilling or a template method. The pore size of the biomimetic sweat gland micropores is designed to be 5–50 μm, and a tapering structure is formed along the radial direction of the pores (i.e., large pore opening and small pore bottom) to create a capillary pressure gradient. This allows the subsequently encapsulated microcapsules to be stably sealed in the untriggered state and to have unidirectional release characteristics after triggering.

[0023] Each biomimetic sweat gland micropore is encapsulated with a phase change microcapsule, which is sealed under capillary constraint. A temperature-sensitive sealing layer composed of a thermosensitive polymer (e.g., poly(N-isopropylacrylamide), PNIPAM) is disposed at the opening of the micropore. Below a preset trigger threshold (e.g., 85°C), this thermosensitive sealing layer is in a swollen and sealed state, tightly sealing the micropore; when the preset trigger threshold is reached or exceeded, the thermosensitive polymer undergoes volume shrinkage and phase transition, reducing the sealing effect on the micropore, thereby opening the micropore, and returning to the swollen and sealed state when the temperature falls below the preset trigger threshold again.

[0024] S2. Continuously monitor the temperature along the flow path. During the high-pressure hydrogen charging and discharging process, embedded distributed sensing units (such as multiple fiber Bragg grating sensors or thin-film thermocouple arrays arranged along the flow channel axis) are used to continuously monitor the temperature along the flow channel and generate local temperature field distribution data in real time.

[0025] S3, Localized overheating-triggered micropore-directed release microcapsules When the local temperature in any area reaches or exceeds the preset trigger threshold (85°C), the temperature-sensitive sealing layer of the biomimetic sweat gland micropores in that area rapidly opens. At this time, driven by the capillary driving force inside the micropores (the pressure gradient generated by the tapered structure) and the high-speed flow shear force of the mainstream hydrogen gas in the flow channel, the microcapsules are directionally and controllably released from the micropores into the mainstream hydrogen gas.

[0026] S4, Microcapsule rupture and phase transition endothermic suppression of peak temperature rise The released microcapsules flow with the mainstream hydrogen gas. Under the influence of flow shear and particle collisions between microcapsules or between microcapsules and the wall, the microcapsule shell ruptures when the applied stress reaches its shell rupture threshold. The microcapsules have a core-shell structure, and the rupture strength of their shell materials (e.g., polyurea or silica) is designed to match the flow shear stress of hydrogen, thus ensuring that they do not rupture within the micropores and rupture controllably in the mainstream. The microcapsules release their internal phase change material (e.g., paraffin, fatty acids, or their eutectic mixtures). The phase change temperature of this material is set within a preset trigger threshold ±5°C (i.e., 80-90°C), so a rapid solid-liquid phase change occurs after release, absorbing a large amount of hydrogen compression heat and frictional heat that cause localized temperature rises, thereby forming a transient endothermic zone locally and effectively suppressing the temperature rise peak.

[0027] S5. The temperature drops sharply during the reverse phase transition in the hydrogen release process. During hydrogen release, the local temperature drops due to gas expansion. When the local temperature falls below a second preset threshold (e.g., -20°C), the phase change material inside the microcapsules within the biomimetic sweat gland micropores undergoes a reverse phase change (i.e., a liquid-solid phase change), releasing stored latent heat. The heat released during the phase change is conducted through the microcapsule shell and porous matrix to the mainstream hydrogen flow channel, thus suppressing the sudden temperature drop caused by gas expansion. This second preset threshold is significantly lower than the preset trigger threshold (85°C) during hydrogen filling.

[0028] Throughout the process, the opening of the biomimetic sweat gland micropores, the release of microcapsules, and the phase change endothermic process all exhibit local adaptive distribution characteristics in space, that is, the response only occurs in the high-heat area, avoiding global waste and achieving precise thermal management.

[0029] Example 2 Based on Example 1, this embodiment optimizes the distribution and flow channel structure of biomimetic sweat gland micropores.

[0030] The biomimetic sweat gland micropores are gradient-distributed along the flow channel axis. Specifically, considering the more significant downstream temperature rise of hydrogen during compression, the micropore distribution density is set to gradually increase with the flow direction. Simultaneously, in the curved regions of the flow channel, due to higher secondary flow and wall shear forces, the temperature rise is more sensitive, thus the micropore distribution density in the curved regions is higher than in the straight regions. This gradient distribution design enables the temperature-sensitive areas to have a higher release response capability, improving the utilization efficiency of the phase change microcapsules.

[0031] Example 3 This embodiment specifically defines the biomimetic streamlined structure of the flow channel body. The flow channel body includes a pressure-reducing inlet zone and a flow-equalizing transition zone arranged sequentially along the flow direction. The pressure-reducing inlet zone is designed as a streamlined diffuser structure with a gradually increasing cross-sectional area along the flow direction (similar to a diffuser tube) to reduce the velocity of high-speed hydrogen inflow and reduce pressure shock. The flow-equalizing transition zone is a straight flow channel with a uniform cross-sectional area. This structural design can effectively reduce flow separation and local turbulence intensity, maintain the uniform dispersion of released microcapsules in the mainstream, prevent premature sedimentation or aggregation, and thus ensure the uniformity and effectiveness of phase change heat absorption.

[0032] Example 4 This embodiment introduces an external collaborative control mechanism. The real-time temperature signal obtained in the temperature monitoring step (S2) is used by the controller to dynamically adjust the external hydrogen charging / discharging rate (e.g., by adjusting the opening of the proportional valve of the hydrogen dispenser) and control the start and stop of auxiliary cooling devices (such as micro fans or semiconductor refrigeration chips). This external active regulation method works in conjunction with the passive phase change endothermic process inside the microcapsule: when the local temperature rise exceeds the endothermic capacity of the microcapsule, the external controller can reduce the hydrogen charging rate to prevent temperature runaway; conversely, when the temperature is well controlled under the action of the microcapsule, the hydrogen charging rate can be maintained or increased. This internal and external collaborative strategy further enhances the temperature regulation effect and improves the hydrogen charging efficiency.

[0033] Example 5 This embodiment provides a detailed description of the materials and cycle life. The porous matrix of the temperature-sensitive active inner wall layer has a thickness of 100-500 μm and a porosity of 30-60%. The total amount of phase change microcapsules encapsulated within the biomimetic sweat gland microporous network has been calculated to be sufficient to support at least 100 complete hydrogen charge-discharge cycles. Simultaneously, the temperature-sensitive polymer sealing layer exhibits good reversibility during repeated temperature cycles (heating to open, cooling to close), allowing for repeated opening and closing. After each hydrogen discharge, slight back pressure or purging can help re-"absorb" unruptured microcapsules or newly added microcapsules into the micropores, contributing to maintaining the distribution stability of the functional materials within the micropores.

[0034] The method and flow channel provided in the above embodiments of the present invention can be widely applied in at least one of the following scenarios: Hydrogen refueling nozzle flow channel: directly installed inside the nozzle head of the hydrogen refueling nozzle, it suppresses local overheating of the nozzle caused by high-pressure gas flow during rapid refueling, thus improving safety.

[0035] Hydrogen storage container inlet / outlet channels: installed at the valve of the 70MPa or 35MPa vehicle-mounted hydrogen storage cylinder, to balance the drastic temperature changes in the cylinder opening area during hydrogen filling and discharging, and to prevent the seals from failing due to thermal shock.

[0036] On-board hydrogen supply system pipeline: As a component of the high-pressure pipeline inside the fuel cell vehicle, it is laid out along the pipeline to solve the problem of multiple hot spots in long pipelines and improve the overall thermal stability and lifespan of the system.

[0037] In summary, the high-pressure hydrogen charging and discharging biomimetic streamlined flow channel temperature rise suppression method provided by this invention, through biomimetic design, constructs a "sweat gland" structure with intelligent response function on the inner wall, achieving in-situ, adaptive, and highly efficient absorption and release of local heat. This method not only effectively suppresses the peak temperature rise during hydrogen charging but also alleviates excessive temperature drop during hydrogen discharging, greatly improving the safety and cycle life of the high-pressure hydrogen storage system, and has significant technological advancements and industrial practical value.

[0038] The above specific embodiments are merely several further embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for suppressing temperature rise in a high-pressure hydrogen charging / discharging biomimetic streamlined flow channel, characterized in that, Includes the following steps: S1. A temperature-sensitive active inner wall layer is constructed on the inner wall of the biomimetic streamlined flow channel body used for high-pressure hydrogen charging and discharging. The temperature-sensitive active inner wall layer is embedded with a biomimetic sweat gland micropore network. The biomimetic sweat gland micropores are encapsulated with phase change microcapsules, and the microcapsules in the micropores are in a capillary confinement and sealing state. A temperature-sensitive sealing layer is provided at the opening of the biomimetic sweat gland micropores. The temperature-sensitive sealing layer closes the micropores when the temperature is below a preset trigger threshold and opens the micropores when the preset trigger threshold is reached or exceeded. S2. During the high-pressure hydrogen charging and discharging process, the temperature along the flow path is continuously monitored, and a local temperature field distribution is formed. S3. When the local temperature of any region reaches or exceeds the preset trigger threshold, the temperature-sensitive sealing layer of the biomimetic sweat gland micropores in the region is opened, so that the microcapsule is directionally released from the micropores into the mainstream hydrogen gas under the coupling effect of capillary driving force and mainstream shear force. S4. When the stress generated by at least one of the flow shearing and particle collision in the mainstream hydrogen reaches its shell rupture threshold, the microcapsule ruptures and releases the internal phase change material. The phase change material undergoes a phase change during the flow and absorbs at least one of the hydrogen compression heat and friction heat that cause local temperature rise, thereby forming a transient heat absorption zone in the local area to suppress the temperature rise peak. S5. During the hydrogen release process, when the local temperature is lower than the second preset threshold, the phase change material in the microcapsules that have not yet been released in the biomimetic sweat gland micropores undergoes a reverse phase change and releases heat to suppress the sudden drop in temperature caused by gas expansion. The second preset threshold is lower than the preset trigger threshold. The opening of the biomimetic sweat gland micropores, the release of microcapsules, and the phase change endothermic process are spatially locally adaptively distributed.

2. The method for suppressing temperature rise in a high-pressure hydrogen charging / discharging biomimetic streamlined flow channel according to claim 1, characterized in that: The biomimetic sweat gland micropores are distributed in a gradient along the flow channel axis, and their distribution density gradually increases with the flow direction. The distribution density in the curved area is higher than that in the straight area, so that the temperature rise sensitive area has a higher release response capability.

3. The method of claim 1, wherein the method is characterized by: The biomimetic sweat gland micropores have a pore size of 5–50 μm and form a radially tapering structure from large to small to create a capillary pressure gradient, which allows the microcapsules to be stably sealed in the untriggered state and to have unidirectional release characteristics after triggering.

4. The method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamline channel according to claim 1, characterized in that: The temperature-sensitive sealing layer is a temperature-sensitive polymer sealing layer. When the temperature is below the trigger threshold, the sealing layer is in a swollen and closed state. When the temperature reaches or exceeds the trigger threshold, it undergoes at least one of the following changes: volume shrinkage and phase transition, in order to reduce the sealing effect on the micropores and open the micropores.

5. The method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamline channel according to claim 1, characterized in that: The microcapsule has a core-shell structure, and the fracture strength of its shell material is matched with the shear stress of hydrogen flow, so that it meets the conditions of not rupturing in the micropores and rupturing controllably in the main flow.

6. The method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamline channel according to claim 1, characterized in that: The phase change temperature of the phase change material is set within the range of ±5℃ of the preset trigger threshold, so that the phase change and heat absorption occur immediately after the microcapsules are released, thereby shortening the thermal response hysteresis time.

7. The method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamline channel according to claim 1, characterized in that: The flow channel body is a biomimetic streamlined structure, including a pressure-reducing inlet zone and a flow-equalizing transition zone arranged sequentially along the flow direction. The pressure-reducing inlet zone is a streamlined diffuser structure with a gradually increasing cross-sectional area along the flow direction. The flow-equalizing transition zone is a straight flow channel with a uniform cross-sectional area. The structure is used to reduce flow separation and local turbulence intensity in order to maintain the uniform dispersion of microcapsules in the mainstream.

8. The method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamline channel according to claim 1, characterized in that: The temperature monitoring is achieved through an embedded distributed sensing unit. The temperature signal output by the sensing unit is used to dynamically adjust the external hydrogen charging and discharging rate and / or control the start and stop of the auxiliary cooling device, so as to coordinate with the phase change endothermic process of the microcapsule and enhance the temperature regulation effect.

9. The method for suppressing temperature rise in a high-pressure hydrogen charging / discharging biomimetic streamlined flow channel according to claim 1, characterized in that: The temperature-sensitive active inner wall layer is a composite structure of a porous matrix and a functional coating. The porous matrix is ​​used to support the microporous network, and the functional coating is used to improve the pressure resistance and impermeability in a hydrogen environment. The total amount of phase change microcapsules encapsulated in the biomimetic sweat gland microporous network is sufficient to support at least 100 complete hydrogen charge-discharge cycles, and the temperature-sensitive sealing layer can be reversibly opened and closed during temperature cycling.

10. The method for suppressing temperature rise in a high-pressure hydrogen charging and discharging biomimetic streamline channel according to claim 1, characterized in that: The flow channel body is used in at least one of the following: hydrogen refueling gun flow channel, hydrogen storage container inlet and outlet gas channel, and vehicle-mounted hydrogen supply system pipeline.

Images