Immersed liquid cooling solid hydrogen storage system and method

Abstract

The invention relates to the technical field of solid-state hydrogen storage, in particular to an immersed liquid-cooling solid-state hydrogen storage system and an immersed liquid-cooling solid-state hydrogen storage method, which realize efficient, energy-saving and precise temperature control solid-state hydrogen storage. Comprising a confining liquid pool filled with a heat exchange medium; the hydrogen storage tank is immersed in the liquid pool, and a heat exchange medium circulation flowing space is formed between the inner wall of the liquid pool and the outer wall of the hydrogen storage tank; a hydrogen inlet / outlet is formed in the top of the tank and communicated with the outside through a pipeline penetrating the liquid pool; the main nozzles are close to the hydrogen inlet and outlet, are uniformly distributed along the circumferential direction of the side wall of the tank and face the surface of the tank body; the auxiliary nozzle is arranged at the bottom of the tank and is obliquely arranged along the axial direction or the axial direction of the tank; the controller is in signal connection with the main nozzle and the auxiliary nozzle; and the temperature sensor is arranged on the outer wall of the tank and / or in the liquid pool and is in signal connection with the controller. Through the steps of system initialization, enhanced heat exchange starting, heat balance establishment and dynamic temperature control, liquid pool temperature self-maintaining and hydrogen storage tank precise temperature control are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid-state hydrogen storage, and in particular to an immersion liquid-cooled solid-state hydrogen storage system and method. Background Art

[0002] With the rapid development of hydrogen energy technology, solid-state hydrogen storage materials (such as LaNi5) have become a research hotspot due to their high safety and high hydrogen storage density. However, thermal management issues during the hydrogen absorption (exothermic) and desorption (endothermic) processes of hydrogen storage materials have been a key bottleneck restricting their practical application. Traditional hydrogen storage tank cooling technologies rely primarily on passive heat dissipation or simple active cooling methods, which have the following significant shortcomings: 1. Low efficiency of passive heat dissipation Traditional technologies often rely on natural convection for heat dissipation, resulting in a heat transfer coefficient (h) typically below 200 W / m²·K. This prevents rapid heat transfer and severely limits the rate of hydrogen absorption and desorption reactions. In particular, during the hydrogen absorption process, the large amount of heat released by the hydrogen storage material is difficult to dissipate in a timely manner, which can easily cause localized overheating and affect material performance and service life.

[0003] 2. Insufficient heating The hydrogen desorption process is an endothermic reaction that requires precise heat input to maintain the reaction rate. Existing designs often rely on external heaters, which not only increases system complexity but also makes it difficult to achieve uniform heating, resulting in low reaction efficiency or uneven localized temperature in the material.

[0004] 3. High energy consumption Some active cooling technologies use continuous injection, which improves heat transfer efficiency but significantly increases pumping power consumption and lacks energy-saving optimization. For example, continuously operating cooling systems consume excessive energy and are inconsistent with the development trend of green energy technology.

[0005] 4. Limitations of regulation Existing technologies often use fixed nozzle positions and parameters, making them incapable of real-time adjustment based on dynamic heat loads. During the hydrogen absorption and desorption process, heat loads fluctuate with reaction rates, making it difficult for cooling systems with fixed parameters to adapt to these dynamic demands, leading to unstable heat exchange efficiency.

[0006] 5. Complex structure To address heat transfer issues, some existing technologies (such as CN118328293A) employ internal heat exchange tubes or enhance heat transfer by separating liquid cooling spaces (such as CN117712558A). While these approaches improve performance to a certain extent, they significantly increase system complexity, raising manufacturing costs, introducing potential leakage risks, and reducing system reliability.

[0007] In summary, traditional hydrogen storage tank cooling technology has obvious defects in efficiency, energy consumption, control flexibility and structural simplification. There is an urgent need for an efficient, energy-saving, intelligent and simple thermal management solution to meet the actual application needs of solid-state hydrogen storage materials. Summary of the Invention

[0008] The purpose of the present invention is to provide an immersion liquid-cooled solid-state hydrogen storage system and method, which solves the problems of low heat dissipation efficiency, insufficient heating, high energy consumption, rigid regulation and complex structure in traditional hydrogen storage technology, and realizes efficient, energy-saving and precisely temperature-controlled solid-state hydrogen storage.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is: A first aspect of the present invention provides an immersion-type liquid-cooled solid-state hydrogen storage system, comprising a closed liquid pool filled with a heat exchange medium; A hydrogen storage tank is vertically immersed in the closed liquid pool, and a space for heat exchange medium circulation is formed between the inner wall of the closed liquid pool and the outer wall of the hydrogen storage tank; a hydrogen inlet and outlet are opened on the top of the hydrogen storage tank, and the hydrogen inlet and outlet are connected to the outside world through a pipeline passing through the closed liquid pool; A main nozzle is provided near the hydrogen inlet and outlet of the hydrogen storage tank and is evenly distributed along the circumference of the side wall of the hydrogen storage tank through a fixed bracket; the main nozzle is oriented toward the surface of the hydrogen storage tank body; the main nozzle is used to directionally spray the heat exchange medium in the closed liquid pool onto the surface of the hydrogen storage tank, thereby enhancing the heat exchange on the surface of the hydrogen storage tank through turbulent impact; A secondary nozzle, the secondary nozzle is arranged at the bottom of the hydrogen storage tank through a fixed bracket, and the secondary nozzle is arranged along the axial direction of the hydrogen storage tank or is arranged axially inclined; the secondary nozzle promotes the overall circulation flow of the medium in the closed liquid pool by spraying the heat exchange medium; A controller, the controller being disposed outside the closed liquid pool and being signal-connected to the main nozzle and the auxiliary nozzle; A temperature sensor is provided on the outer wall of the hydrogen storage tank and / or in the closed liquid pool and is connected to the controller signal for real-time monitoring of the temperature of the hydrogen storage material and the temperature distribution of the liquid pool.

[0010] Furthermore, the number of the main nozzles is 4 to 8, and the number of the auxiliary nozzles is ≥2.

[0011] Furthermore, the outlet diameter of the main nozzle is smaller than the outlet diameter of the auxiliary nozzle; the outlet diameter of the main nozzle is 18-22 mm, and the outlet diameter of the auxiliary nozzle is 76-84 mm.

[0012] Furthermore, the outlet diameter of the main nozzle is 20 mm, and the outlet diameter of the auxiliary nozzle is 80 mm.

[0013] Furthermore, the flow rate of the main nozzle is 2~6m / s, the pulse frequency is 20~40 Hz, and the duty cycle is 40%~90%; the flow rate of the auxiliary nozzle is 0.4~2.5m / s, the pulse frequency is 1~5 Hz, and the duty cycle is 10.8%~95%.

[0014] Furthermore, the injection direction of the main nozzle is tilted relative to the tangential direction of the hydrogen storage tank, and the tilt angle is 30°~60°.

[0015] Furthermore, the spraying direction of the secondary nozzle is arranged along the axial direction of the hydrogen storage tank or is inclined in the axial direction, and the inclination angle is 0°~30°.

[0016] Furthermore, the liquid level in the closed liquid pool is higher than the top of the hydrogen storage tank, and the distance between the liquid level and the top of the hydrogen storage tank is 0.3 m.

[0017] A second aspect of the present invention provides an immersion liquid-cooled solid-state hydrogen storage method, comprising the following steps: S1 system initialization: immerse the hydrogen storage tank in the liquid pool, fill the liquid pool with heat exchange medium; at the same time, choose whether to perform circulation preheating according to the initial temperature of the liquid pool; S2 enhanced heat exchange start: Start the main nozzle, and spray the heat exchange medium at a certain angle along the side wall of the hydrogen storage tank at the set pulse frequency, duty cycle and flow rate to form turbulent heat exchange; synchronously start the auxiliary nozzle, and promote the circulation of the heat exchange medium at the set pulse frequency, duty cycle and flow rate to establish the overall flow of the global medium; S3 Thermal Balance Establishment: When cyclic preheating is required, the thermal equilibrium temperature in the liquid pool is maintained at 70~75℃ by repeatedly performing hydrogen absorption and desorption cycles for at least 100 cycles and utilizing the hydride reaction heat to preheat the system; S4 dynamic temperature control: Based on temperature sensor feedback, the controller dynamically optimizes the nozzle parameter combination to achieve self-maintenance of the liquid pool temperature at 70~75℃ and the thermal equilibrium temperature of the hydrogen storage tank at 30~50℃.

[0018] Furthermore, in step S1, the heat exchange medium is preferably water.

[0019] Furthermore, in step S4, when optimizing the nozzle parameter combination based on the temperature sensor feedback, dynamic adjustment is performed through PID and machine learning.

[0020] Furthermore, in step S4, when the hydrogen storage system performs hydrogen absorption operation and monitors that the surface temperature of the hydrogen storage tank is greater than 50°C, the duty cycle of the main nozzle is increased and the flow rate of the main nozzle is reduced; when the hydrogen storage system performs hydrogen absorption operation and monitors that the surface temperature of the hydrogen storage tank is less than 30°C, the duty cycle of the secondary nozzle is reduced or the number of main nozzles is increased; when the hydrogen storage system performs hydrogen discharge operation and monitors that the bottom temperature of the hydrogen storage tank is less than 30°C, the duty cycle of the secondary nozzle is reduced; when the hydrogen storage system performs hydrogen discharge operation and monitors that the bottom temperature of the hydrogen storage tank is greater than 50°C, the duty cycle of the secondary main nozzle is increased or the number of main nozzles is reduced. Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: (1) The heat transfer efficiency is greatly improved through the synergistic effect of the turbulent impact of the main nozzle and the global flow driven by the secondary nozzle. The application of pulse jet technology greatly reduces the power consumption of the system, significantly improves the energy utilization efficiency, and the system shows excellent process adaptability.

[0021] (2) By utilizing the reversible reaction thermal characteristics of the hydrogen absorption and desorption process, the self-circulating utilization of energy is achieved through the intelligently controlled liquid pool preheating mechanism, eliminating the traditional required external heating device and greatly reducing the overall energy consumption.

[0022] (3) By eliminating complex components such as guide plates and heat exchange tubes and replacing them with a fully immersed design, the risk of leakage is fundamentally eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings: Figure 1 A schematic structural diagram of an immersion liquid-cooled solid-state hydrogen storage system provided by the present invention (I); Figure 2 A schematic structural diagram of an immersion liquid-cooled solid-state hydrogen storage system provided by the present invention (II); Figure 3 A cross-sectional view of an immersion liquid-cooled solid-state hydrogen storage system provided by the present invention; Figure 4 A cross-sectional view of an immersion liquid-cooled solid-state hydrogen storage system provided by the present invention; Figure 5 A schematic diagram of the control structure of an immersion liquid-cooled solid-state hydrogen storage system provided by the present invention; The accompanying drawings are described as follows: 1. Closed liquid pool; 2. Hydrogen storage tank; 201. Hydrogen inlet and outlet; 3. Main nozzle; 4. Auxiliary nozzle; 5. Controller; 6. Temperature sensor. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] See Figures 1 to 5 The present invention discloses an immersion liquid-cooled solid-state hydrogen storage system comprising a closed liquid pool 1, a hydrogen storage tank 2, a main nozzle 3, a secondary nozzle 4, a controller 5 and a temperature sensor 6.

[0026] The enclosed liquid pool 1 is filled with a heat exchange medium. This enclosed liquid pool can reduce heat convection losses, thereby reducing temperature fluctuations within the pool and improving heat retention efficiency within the pool. Furthermore, the enclosed environment avoids interference from external airflow, making the temperature distribution of the heat exchange medium more uniform and preventing evaporation losses of the heat exchange medium within the pool. The heat exchange medium can be thermal oil, water, or other liquid with good thermal conductivity.

[0027] Hydrogen tank 2 is vertically immersed in a closed liquid pool 1. A space for heat exchange medium circulation is formed between the inner wall of the closed liquid pool 1 and the outer wall of the hydrogen tank 2. A hydrogen inlet and outlet 201 is provided at the top of the hydrogen tank 2. This inlet and outlet 201 is connected to the outside world via a pipe that penetrates the closed liquid pool 1.

[0028] The fully submerged structure enables heat exchange without blind spots in hydrogen tank 2, significantly improving heat exchange area utilization and surface temperature uniformity. Hydrogen tank 2 is filled with a solid hydrogen storage material, which can be a metal hydride, composite hydride, or other high-efficiency hydrogen storage material. A hydrogen inlet and outlet pipe is installed at the top of hydrogen tank 2, connecting it to an external hydrogen supply system and hydrogen-using equipment.

[0029] Furthermore, the liquid level in enclosed liquid pool 1 is higher than the top of hydrogen tank 2, with a distance of 0.3m between the liquid level and the top of hydrogen tank 2, ensuring that hydrogen tank 2 is completely immersed in the heat exchange medium, enabling full-scale heat exchange. Maintaining a certain margin in the liquid level compensates for the volume expansion of the heat exchange medium during temperature changes and prevents excessive system pressure.

[0030] The main nozzle 3 is positioned near the hydrogen inlet / outlet 201 on the hydrogen storage tank 2. This is because the area near the hydrogen inlet / outlet 201 generates more heat than other areas, and corresponds to the concentrated exothermic reaction zone of the solid hydrogen storage material. Therefore, the main nozzle 3 is positioned near the hydrogen inlet / outlet 201. In this example, since the hydrogen inlet / outlet 201 is located at the top of the hydrogen storage tank 2, the main nozzle 3 is located in the upper region of the hydrogen storage tank 2. Of course, the placement of the main nozzle 3 can be adjusted according to actual needs.

[0031] The main nozzles 3 are evenly distributed along the circumference of the sidewall of the hydrogen storage tank 2 via a fixed bracket (not shown). The main nozzles 3 are oriented toward the surface of the hydrogen storage tank 2. They are used to spray the heat exchange medium in the closed liquid pool 1 onto the surface of the hydrogen storage tank 2 in a targeted manner, enhancing the heat exchange on the surface of the hydrogen storage tank 2 through turbulent impact. In this example, the number of main nozzles 3 is 4 to 8, the outlet diameter is 18 to 22 mm, the flow rate of the main nozzles 3 is 2 to 6 m / s, the pulse frequency is 20 to 40 Hz, and the duty cycle is 40% to 90%. The injection direction of the main nozzles 3 is tilted relative to the tangent direction of the hydrogen storage tank 2 at an angle of 30° to 60°, thereby forming a spiral flow path and enhancing the turbulent effect.

[0032] Specifically, the tangential velocity component of the inclined jet forms a circumferential vortex in the liquid pool, which, when superimposed with the axial flow, forms a spiral three-dimensional turbulence. This flow structure significantly increases the fluid shear force and vortex intensity, destroying the boundary layer and significantly improving the heat transfer coefficient. At the same time, the inclination angle is set at 30° to 60°. By adjusting the ratio of tangential to axial velocities, it ensures that the jet can fully impact the tank wall (axial component) and drive the overall rotation of the liquid pool (tangential component), avoiding flow dead zones and achieving uniform heat exchange on the surface of hydrogen storage tank 2.

[0033] The spiral flow path is significantly longer than that of linear flow, extending the contact time between the coolant and the tank wall. The centrifugal effect also propels the high-temperature fluid toward the center of the pool, promoting global heat diffusion. During the hydrogen absorption (strong heat release) phase, a larger angle (e.g., 60°) can be used to enhance turbulence; during the hydrogen release (heat absorption) phase, a smaller angle (e.g., 30°) can be used to reduce flow rate, thus matching different thermal management requirements.

[0034] A secondary nozzle 4 is mounted on the bottom of the hydrogen tank 2 via a fixed bracket (not shown). The secondary nozzle 4 is oriented axially or tilted axially along the hydrogen tank 2, and by spraying heat exchange medium, it promotes the overall circulation of the medium within the enclosed liquid pool 1. In this example, the number of secondary nozzles 4 is ≥2, with a flow rate of 0.4-2.5 m / s, a pulse frequency of 1-5 Hz, and a duty cycle of 10.8%-95%. The spray direction of the secondary nozzle 4 is tilted at an angle of 0°-30° along the hydrogen tank 2, thereby forming an ascending spiral flow path and macroscopic circulation throughout the liquid pool.

[0035] Specifically, the outlet diameter (76-84 mm) and low velocity (0.4-2.5 m / s) of the secondary nozzle 4 result in a high jet momentum but low velocity, pushing the coolant in the pool upward axially, forming a stable vertical flow. A slight inclination (e.g., 10°-30°) can superimpose a weak swirl component on the axial flow, synergizing with the strong turbulence of the primary nozzle 3 to form an ascending spiral path, further reducing dead zones and ensuring uniform pool temperature.

[0036] The spiral jet of the main nozzle 3 is coupled with the rising flow of the auxiliary nozzle 4 to realize an efficient heat transfer path from the tank wall → the center of the liquid pool → the top of the liquid pool → the bottom.

[0037] The controller 5 is arranged outside the closed liquid pool 1 and is signal-connected to the main nozzle 3 and the auxiliary nozzle 4, and can adjust the nozzle parameters according to the operating status of the system.

[0038] In the present invention, a temperature sensor 6 is also provided, which is connected to the aforementioned controller 5 signal. The temperature sensor 6 can be set on the outer wall of the hydrogen storage tank 2, or can be set in the closed liquid pool 1, or can be set at the outer wall of the hydrogen storage tank 2 and in the closed liquid pool 1 at the same time, for real-time monitoring of the temperature of the hydrogen storage material and the temperature distribution of the liquid pool.

[0039] The present invention also provides an immersion liquid-cooled solid-state hydrogen storage method, which is implemented using the above-mentioned immersion liquid-cooled solid-state hydrogen storage system. Specifically, it includes the following steps: S1 system initialization: immerse the hydrogen storage tank 2 in the liquid pool, fill the liquid pool with heat exchange medium; at the same time, choose whether to perform circulation preheating according to the initial temperature of the liquid pool; S2 enhanced heat exchange start: start the main nozzle 3, and spray the heat exchange medium at a certain angle along the side wall of the hydrogen storage tank 2 under the set pulse frequency, duty cycle and flow rate to form turbulent heat exchange; synchronously start the auxiliary nozzle 4, and promote the circulation of the heat exchange medium under the set pulse frequency, duty cycle and flow rate to establish the overall flow of the global medium; S3 Thermal Balance Establishment: When cyclic preheating is required, the thermal equilibrium temperature in the liquid pool is maintained at 70~75℃ by repeatedly performing hydrogen absorption and desorption cycles for at least 100 cycles and utilizing the hydride reaction heat to preheat the system; S4 dynamic temperature control: Based on the feedback from the temperature sensor 6, the controller 5 dynamically optimizes the nozzle parameter combination to achieve the self-maintenance of the liquid pool temperature at 70~75℃ and the thermal equilibrium temperature of the hydrogen storage tank at 30~50℃. Regarding step S1 above, when the initial temperature of the liquid pool in the system is about 20°C, the system needs to be preheated in a circulation manner. When the initial temperature of the liquid pool in the system is about 70°C, the system does not need to be preheated in a circulation manner and can be directly advanced to the next step.

[0040] For the above step S3, when establishing thermal equilibrium, the system first uses the inherent thermal characteristics of the hydrogen absorption and desorption cycle (hydrogen absorption heat release / hydrogen desorption heat absorption are both 21651 kJ) for self-preheating. After at least 100 cycles, the liquid pool temperature slowly rises from 20°C to 70°C. During this process, the nozzle parameters are dynamically adjusted (such as the main nozzle duty cycle of 90% in the hydrogen absorption stage and reduced to 40% in the hydrogen desorption stage) to ensure that the surface temperature of the hydrogen storage tank 2 is always stable in the optimal working range of the LaNi5 material (30~50°C).

[0041] Both hydrogen absorption and desorption reactions are reversible, with equal absolute heat values (Q = 21651 kJ). Specifically, during hydrogen absorption, the liquid pool absorbs all the heat (21651 kJ), resulting in a temperature rise of 0.781°C; during desorption, the liquid pool releases heat (21651 kJ), resulting in a temperature drop of 0.786°C. Because the desorption time (600 s) is longer than the absorption time (300 s), the heat dissipated during hydrogen absorption (2447 kJ) is less than that during desorption (4974 kJ). This asymmetry in heat loss results in a net heat generation of 14230 kJ during the hydrogen absorption and desorption cycle preheating. The liquid pool temperature rises by 0.514°C during this cycle. As the cycle preheats, the liquid pool temperature slowly rises to the target equilibrium temperature.

[0042] It is worth noting that although the liquid pool temperature reaches 70°C, the actual temperature of hydrogen storage tank 2 is strictly controlled below 50°C due to the ultra-efficient heat exchange capability of the nozzle system supplemented by PID control and machine learning. This is achieved by real-time monitoring of the temperature gradient and dynamic adjustment of the main / auxiliary nozzle flow distribution to ensure that the hydrogen absorption efficiency is not affected. The final thermal balance is manifested as: the axial temperature difference of the liquid pool ≤ 2°C, the maximum temperature difference on the surface of the hydrogen storage tank <3°C, the hydrogen production fluctuation rate <2%, and the system has anti-disturbance capabilities and can restore balance within 2 minutes when the hydrogen production rate changes suddenly. This unique thermal management mechanism eliminates the need for traditional heaters and heat exchangers, and only achieves the dual needs of hydrogen absorption cooling and hydrogen desorption heating through pulse jet energy-saving design (energy consumption is greatly reduced) and the use of liquid pool thermal inertia.

[0043] The technical solution of the present invention is further described below through specific embodiments: Example 1 (hydrogen absorption cooling) Structural parameters: (1) Hydrogen storage tank: D = 1.5 m, H = 3.0 m, A = 14.14 m², 316L stainless steel.

[0044] (2) Main nozzles: number N = 8, θ ≈ 45° (circumferential angle interval between two adjacent nozzles), outlet diameter d = 20 mm, flow velocity v = 6.0 m / s, injection angle α = 60°, pulse frequency 30 Hz, duty cycle 80%, and flexibly arranged on the side wall of the tank.

[0045] (3) Auxiliary nozzles: number N = 2, outlet diameter d = 80 mm, flow velocity v = 2.5 m / s, pulse frequency 2 Hz, duty cycle 95%, arranged at the bottom of the liquid pool, with the axis vertical or inclined at a certain angle.

[0046] Heat transfer coefficient: (1) Main nozzle: Re = 120,000, h ≈ 14,000 W / m²·K.

[0047] (2) Secondary nozzle: Re = 200,000, h ≈ 12,000 W / m²·K.

[0048] The total power is 122.22 kW, satisfying P=72.17 kW.

[0049] (3) Liquid pool: The heat exchange medium is water (ρ = 1000 kg / m³, μ = 0.001 Pa·s), with a mass of 6,630 kg and a volume of 6.63 m³. It is adapted to a cylindrical liquid pool (D = 1.6 m, H = 3.3 m), completely submerging the hydrogen storage tank, with the liquid level exceeding the top by 0.3 m. The inlet temperature T_in = 20°C and the temperature rise ΔT = 0.781°C.

[0050] Controller control: The temperature sensor monitors the surface of the hydrogen storage tank (30~50°C).

[0051] If T>50°C, increase the main nozzle duty cycle to 90%, and the main nozzle v=5.5 m / s.

[0052] If T<30°C, the duty cycle of the secondary nozzle is reduced to 94%, or the number of main nozzles is increased to N=14.

[0053] Example 2 (hydrogen release heating) Structural parameters: (1) Hydrogen storage tank: D = 1.5 m, H = 3.0 m, A = 14.14 m², 316L stainless steel.

[0054] (2) Auxiliary nozzle: N = 2, d = 80 mm, v = 0.4 m / s, 2 Hz, duty cycle 10.8% (control range 10%~15%), axis can be tilted 0°~30°.

[0055] (3) Main nozzle: N = 4, d = 20 mm, v = 2.0 m / s, 20 Hz, duty cycle 40%, auxiliary heat exchange, flexible arrangement.

[0056] (4) Liquid pool: 6,630 kg, 6.63 m³ (D = 1.6 m, H = 3.3 m), T_init = 70°C (residual heat from multi-cycle hydrogen absorption), ΔT = 20°C (T_out = 50°C).

[0057] Heat transfer coefficient: Main nozzle: Re=120,000, h≈14,000 W / m²·K.

[0058] Secondary nozzle: Re=200,000, h≈12,000 W / m²·K.

[0059] Controller control: The temperature sensor monitors the bottom of the hydrogen storage tank (30~50°C).

[0060] If T < 30 °C, the duty cycle of the secondary nozzle is reduced to 10% (P ≈ 33.605 kW).

[0061] If T>50°C, the secondary nozzle duty cycle increases to 15%, or N=2 (primary nozzle).

[0062] Example 3 (Dual Mode Switching) Structural parameters: same as Examples 1 and 2.

[0063] Operation process: Hydrogen absorption stage: the main nozzle (N=8, v=6.0 m / s, 30 Hz, duty cycle 90%) enhances turbulence, the secondary nozzle (v=2.5 m / s, duty cycle 95%) promotes flow, circulation 6.630 kg, T_in=20°C.

[0064] Hydrogen degassing phase: the liquid pool was preheated to T_init = 70°C, the secondary nozzle (v = 0.4 m / s, duty cycle 10.8%) circulated 260.64 kg, and the main nozzle (N = 4, v = 2.0 m / s) assisted.

[0065] Switch control: The controller adjusts the nozzle parameters.

[0066] performance: Hydrogen absorption: Q=21,651 kJ, h≈12,000 W / m²·K.

[0067] Hydrogen release: Q=21,651 kJ, h≈8,000 W / m²·K.

[0068] It can be seen that under dual-mode switching, the heat exchange efficiency of the main and auxiliary nozzles is very high, no heaters or heat exchangers are stacked, and pulse injection optimizes energy consumption.

[0069] In summary, the submerged liquid-cooled solid-state hydrogen storage system and method disclosed herein achieves efficient thermal management of solid-state hydrogen storage materials (such as LaNi5) during the hydrogen absorption (exothermic) and desorption (endothermic) processes through the coordinated design of a tangential spiral jet from a primary nozzle and an axial macro-circulation from a secondary nozzle, combined with pulsed energy-saving control and liquid pool preheating technology. This overcomes key issues inherent in traditional hydrogen storage technologies, such as low heat exchange efficiency, high energy consumption, and complex structures, providing an efficient, reliable, and low-cost solution for the large-scale application of solid-state hydrogen storage, with significant potential for industrialization.

[0070] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An immersion liquid-cooled solid-state hydrogen storage system, characterized in that: include: A closed liquid pool (1), wherein the closed liquid pool (1) is filled with a heat exchange medium; A hydrogen storage tank (2), the hydrogen storage tank (2) being vertically immersed in the closed liquid pool (1), a space for heat exchange medium to circulate is formed between the inner wall of the closed liquid pool (1) and the outer wall of the hydrogen storage tank (2); a hydrogen inlet and outlet (201) is provided on the top of the hydrogen storage tank (2), and the hydrogen inlet and outlet (201) is connected to the outside world through a pipeline penetrating the closed liquid pool (1); A main nozzle (3), the main nozzle (3) is arranged near the hydrogen inlet and outlet (201) of the hydrogen storage tank (2), and is evenly distributed along the circumference of the side wall of the hydrogen storage tank (2) through a fixed bracket; the main nozzle (3) is oriented toward the surface of the tank body of the hydrogen storage tank (2); the main nozzle (3) is used to spray the heat exchange medium in the closed liquid pool (1) toward the surface of the hydrogen storage tank (2), thereby enhancing the heat exchange on the surface of the hydrogen storage tank (2) through turbulent impact; A secondary nozzle (4), the secondary nozzle (4) is arranged at the bottom of the hydrogen storage tank (2) through a fixed bracket, and the secondary nozzle (4) is arranged along the axial direction of the hydrogen storage tank (2) or is arranged with an axial inclination; the secondary nozzle (4) promotes the overall circulation flow of the medium in the closed liquid pool (1) by spraying the heat exchange medium; A controller (5), the controller (5) being arranged outside the closed liquid pool (1), the controller (5) being signal-connected to the main nozzle (3) and the auxiliary nozzle (4); A temperature sensor (6) is provided on the outer wall of the hydrogen storage tank (2) and / or in the closed liquid pool (1), and is connected to the controller (5) for signal communication, and is used for real-time monitoring of the temperature of the hydrogen storage material and the temperature distribution of the liquid pool.

2. The immersion liquid-cooled solid-state hydrogen storage system according to claim 1, characterized in that: The number of the main nozzles (3) arranged is 4 to 8, and the number of the auxiliary nozzles (4) arranged is ≥2.

3. The submerged liquid-cooled solid-state hydrogen storage system according to claim 1, characterized in that: The outlet diameter of the main nozzle (3) is smaller than the outlet diameter of the auxiliary nozzle (4); the outlet diameter of the main nozzle (3) is 18-22 mm, and the outlet diameter of the auxiliary nozzle (4) is 76-84 mm.

4. The immersion liquid-cooled solid-state hydrogen storage system according to claim 2, characterized in that: The flow rate of the main nozzle (3) is 2-6 m / s, the pulse frequency is 20-40 Hz, and the duty cycle is 40%-90%; the flow rate of the auxiliary nozzle (4) is 0.4-2.5 m / s, the pulse frequency is 1-5 Hz, and the duty cycle is 10.8%-95%.

5. The immersion liquid-cooled solid-state hydrogen storage system according to claim 1, characterized in that: The spraying direction of the main nozzle (3) is tilted relative to the tangential direction of the hydrogen storage tank (2), and the tilt angle is 30° to 60°.

6. The immersion liquid-cooled solid-state hydrogen storage system according to claim 1, characterized in that: The spraying direction of the auxiliary nozzle (4) is arranged along the axial direction of the hydrogen storage tank (2) or is arranged axially inclined, with an inclination angle of 0° to 30°.

7. An immersion liquid-cooled solid-state hydrogen storage method, using the immersion liquid-cooled solid-state hydrogen storage system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1 system initialization: immerse the hydrogen storage tank in the liquid pool, fill the liquid pool with heat exchange medium; at the same time, choose whether to perform circulation preheating according to the initial temperature of the liquid pool; S2 enhanced heat exchange start: Start the main nozzle and spray the heat exchange medium at a certain angle along the side wall of the hydrogen storage tank at the set pulse frequency, duty cycle and flow rate to form turbulent heat exchange; Synchronously start the auxiliary nozzle to promote the circulation of heat exchange medium under the set pulse frequency, duty cycle and flow rate, and establish the overall flow of global medium; S3 Thermal Balance Establishment: When cyclic preheating is required, the thermal equilibrium temperature in the liquid pool is maintained at 70~75℃ by repeatedly performing hydrogen absorption and desorption cycles for at least 100 cycles and utilizing the hydride reaction heat to preheat the system; S4 dynamic temperature control: Based on temperature sensor feedback, the controller dynamically optimizes the nozzle parameter combination to achieve self-maintenance of the liquid pool temperature at 70~75℃ and the thermal equilibrium temperature of the hydrogen storage tank at 30~50℃.

8. The immersion liquid-cooled solid-state hydrogen storage method according to claim 7, characterized in that: In step S4, when optimizing the nozzle parameter combination based on the temperature sensor feedback, dynamic adjustment is performed through PID and machine learning.

9. The immersion liquid-cooled solid-state hydrogen storage method according to claim 7, characterized in that: In step S4, when the hydrogen storage system performs hydrogen absorption operation and monitors that the surface temperature of the hydrogen storage tank is greater than 50°C, the duty cycle of the main nozzle is increased and the flow rate of the main nozzle is reduced; when the hydrogen storage system performs hydrogen absorption operation and monitors that the surface temperature of the hydrogen storage tank is less than 30°C, the duty cycle of the auxiliary nozzle is reduced or the number of main nozzles is increased; when the hydrogen storage system performs hydrogen discharge operation and monitors that the bottom temperature of the hydrogen storage tank is less than 30°C, the duty cycle of the auxiliary nozzle is reduced; when the hydrogen storage system performs hydrogen discharge operation and monitors that the bottom temperature of the hydrogen storage tank is greater than 50°C, the duty cycle of the auxiliary main nozzle is increased or the number of main nozzles is reduced.

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