Heat storage type magnesium-based hydrogen storage device for maintaining temperature stability of reaction bed layer

Abstract

The invention relates to the technical field of hydrogen solid state storage, in particular to a heat storage type magnesium-based hydrogen storage device capable of maintaining the temperature of a reaction bed to be stable, the device comprises a heat exchange fluid pipeline formed by nesting a heat exchange fluid inlet pipe and a heat exchange fluid outlet pipe, the heat exchange fluid inlet pipe is arranged in the heat exchange fluid outlet pipe, and the heat exchange fluid outlet pipe is arranged in the heat exchange fluid pipeline. The heat exchange fluid pipelines are arranged on concentric circles with the circle center of the base plate as the circle center, the heat exchange fluid pipelines are perpendicularly arranged on the base plate, and the distances between the circle centers of the adjacent heat exchange fluid pipelines on the cross section of the base plate are equal; the ventilation pipe is arranged in the center of the base plate, the ventilation pipe is a hollow straight pipe, the pipe wall is of a porous structure, the ventilation pipe is connected with the base plate, and the magnesium-based hydrogen storage material tray, the magnesium-based hydrogen storage material and the heat storage phase change material sealing box are sequentially stacked and filled in the metal shell from bottom to top. All parts of the device uniformly absorb and release hydrogen to prevent the hydrogen from directly reaching the bottom of the device due to material hardening, so that the reaction efficiency of the device is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state hydrogen storage, and in particular relates to a heat storage type magnesium-based hydrogen storage device for maintaining a stable temperature of a reaction bed. Background Art

[0002] With the reduction of consumption of petrochemical energy such as coal, oil, and natural gas and the intensification of environmental pollution, hydrogen energy, as an easily available pure green and clean energy, has attracted more and more attention. However, there are still many technical problems that need to be solved for the safe, efficient and economical application of hydrogen energy, which has gradually become a new hot spot of people's attention.

[0003] At present, magnesium-based hydrogen storage devices will generate a large amount of heat / cold during the hydrogen absorption / desorption process, causing the temperature of the device to increase or decrease, which will inhibit the hydrogen absorption and desorption performance of the material. To solve this problem, many devices choose to introduce an all-in-one cold and hot machine to provide cold energy for the hydrogen absorption process of the device and heat for the hydrogen desorption process of the device. However, using only an all-in-one cold and hot machine will greatly increase the energy consumption of the system and reduce the economy of the system.

[0004] During the process of absorbing and releasing hydrogen, the magnesium-based hydrogen storage material will experience material lattice expansion, which will cause the material volume to increase, resulting in greater stress on the outer wall of the hydrogen storage device, causing local stress accumulation in the hydrogen storage device, shortening the life of the device, and easily causing accidents. Hydrogen storage alloys will generate a large amount of heat or cold during the process of absorbing and releasing hydrogen. If the heat or cold cannot be transferred to the outside of the alloy, the hydrogen absorption and desorption effect of the alloy will be seriously affected. Therefore, most hydrogen storage containers are equipped with heat transfer structures such as heat pipes or fins.

[0005] The magnesium hydride hydrogen storage device of the prior art uses a trapezoidal magnesium hydride powder box to store magnesium-based hydrogen storage materials. At the same time, a thermal pad, nickel foam and magnesium hydride powder box are used as heat transfer structures to transfer heat to the outside to prevent the phenomenon that the reaction rates of the inner and outer layers are inconsistent due to uneven temperatures. However, the above structure will cause the structure of the magnesium-based hydrogen storage device to be complex and difficult to manufacture, with high costs, and it will also become difficult to load and unload the hydrogen storage alloy. The more serious problem is that the constructed heat transfer structures such as the trapezoidal magnesium hydride powder box, thermal pad and nickel foam are affected by the high and low temperatures generated by the heat absorption and release of the high-temperature magnesium hydrogen storage system for a long time, and are easily damaged, which shortens the life of the device and even causes accidents.

[0006] In summary, there is an urgent need for a hydrogen storage device with stable device temperature, excellent hydrogen absorption and desorption effects, and long service life. Summary of the invention

[0007] The present invention aims to solve the technical problem of how to keep the temperature stable during the hydrogen absorption and desorption process of a hydrogen storage device, ensure the hydrogen absorption and desorption efficiency, and increase the service life of the device. The present invention provides a magnesium-based hydrogen storage device with a heat storage type for maintaining a stable reaction bed temperature. Among them, the magnesium-based hydrogen storage device includes a hydrogen charging / discharging port, a heat exchange fluid pipeline, a ventilation pipe, N hydrogen storage and heat storage units, a metal shell, a chassis, and a head;

[0008] The hydrogen storage and heat storage unit includes a magnesium-based hydrogen storage material tray, magnesium-based hydrogen storage materials, and a heat storage phase change material sealed box;

[0009] The hydrogen charging / discharging port is arranged on the head and connected to the flange of the head;

[0010] The heat exchange fluid pipeline is composed of M heat exchange fluid inlet pipes and a heat exchange fluid outlet pipe nested together. The heat exchange fluid inlet pipes are arranged inside the heat exchange fluid outlet pipe. The heat exchange fluid pipeline is arranged on a concentric circle with the center of the chassis as the center. The heat exchange fluid pipeline is vertically arranged on the chassis, and the distance between the centers of adjacent heat exchange fluid pipelines in the cross-section of the chassis is equal;

[0011] Both sides of the heat exchange fluid inlet pipe are open, and one side of the heat exchange fluid outlet pipe is open. The opening is arranged on the side close to the chassis. The diameter of the heat exchange fluid inlet pipe is smaller than that of the heat exchange fluid outlet pipe, and the heat exchange fluid outlet pipe is connected to the chassis;

[0012] The ventilation pipe is arranged at the center of the chassis. The ventilation pipe is a hollow straight pipe with a porous wall and is connected to the chassis;

[0013] The heat storage phase change material sealed box is arranged on the magnesium-based hydrogen storage materials. The heat storage phase change material sealed box is provided with a round hole that can pass through the ventilation pipe and is provided with M holes passing through the heat exchange fluid pipeline;

[0014] The center of the magnesium-based hydrogen storage material tray is provided with a round hole that can pass through the ventilation pipe and is provided with M holes passing through the heat exchange fluid pipeline. It is also provided with several ventilation holes perpendicular to the tray. The bottom layer in the hydrogen storage device is the magnesium-based hydrogen storage material tray and is in contact with the chassis. The top layer in the hydrogen storage device is the magnesium-based hydrogen storage material tray;

[0015] The magnesium-based hydrogen storage materials are arranged on the magnesium-based hydrogen storage material tray. The magnesium-based hydrogen storage materials are provided with a round hole that can pass through the ventilation pipe and are provided with M holes passing through the heat exchange fluid pipeline. It is also provided with several ventilation holes perpendicular to the tray;

[0016] The magnesium-based hydrogen storage material tray, the magnesium-based hydrogen storage materials, and the heat storage phase change material sealed box are stacked and filled into the metal shell from bottom to top in sequence;

[0017] Along the axial direction of the hydrogen storage device, the heat exchange fluid pipeline is higher than the ventilation pipe, and the ventilation pipe is higher than the hydrogen storage and heat storage unit.

[0018] Furthermore, the height-diameter ratio of the magnesium-based hydrogen storage device is 2.8 - 3.1:1.

[0019] Furthermore, the filling rate of the magnesium-based hydrogen storage material in the tray of the magnesium-based hydrogen storage material is 78% - 82%.

[0020] Furthermore, the height ratio of the magnesium-based hydrogen storage material to the sealed box of the heat storage phase change material is 1:1.5 - 2.5.

[0021] Furthermore, the distance between the axis of the heat exchange fluid pipeline and the center of the chassis is 0.25 - 0.75 times the radius of the chassis.

[0022] Furthermore, during the hydrogen absorption process of the magnesium-based hydrogen storage material, heat is released, and the heat storage phase change material in the sealed box is heated and liquefied to store heat.

[0023] Furthermore, the phase change material in the sealed box of the heat storage phase change material is molten salt.

[0024] Preferably, the phase change material in the sealed box of the heat storage phase change material is NaNO3 molten salt or KNO3 molten salt.

[0025] Furthermore, the tray of the magnesium-based hydrogen storage material is made of copper.

[0026] Furthermore, the diameter range of the ventilation pipe is 10 - 12 mm.

[0027] Furthermore, the diameter of the heat exchange fluid inlet pipe is 6 - 8 mm.

[0028] Furthermore, the diameter of the heat exchange fluid outlet pipe is 10 - 12 mm.

[0029] Furthermore, M is 4 - 8.

[0030] Beneficial effects:

[0031] (1) The hydrogen storage device provided by the present invention can reduce heat loss during the hydrogen absorption and release processes. The heat released during the hydrogen absorption process is first absorbed by the phase change material in the sealed box of the heat storage phase change material, and the excess part is removed from the device through the heat exchange pipeline, which can maintain the temperature of the device within a suitable temperature range. After hydrogen enters the device, it is evenly distributed axially and evenly distributed radially through the porous structure of the ventilation pipe, avoiding the problem that the heat changes suddenly in the radial direction in traditional heat storage devices, which causes the inactivation of the hydrogen storage material.

[0032] (2) The magnesium-based hydrogen storage device provided by the present invention uses a phase change material storage box. The phase change material is a molten salt, such as NaNO3 and KNO3, which stores heat / cold, absorbs / releases heat during the hydrogen absorption / desorption process, and maintains the temperature field of the reaction bed within the optimal hydrogen absorption / desorption temperature range (310-350°C). At the same time, it reduces the energy consumption generated by the absorption and desorption process of the magnesium-based hydrogen storage bottle, reduces the power consumption of the high and low temperature integrated machine, reduces the overall use and maintenance costs, and improves the economic benefits of the device.

[0033] (3) The arrangement of the heat exchange fluid pipeline inside the magnesium-based hydrogen storage device provided by the present invention effectively increases the heat exchange area, making the heat exchange inside the tank body uniform, and further maintaining the reaction temperature field of the device within a certain constant range during the process of hydrogen absorption and desorption of the material. Through the structure of the heat exchange tube and the tray, the heat exchange between the fluid and the material inside the hydrogen storage device is uniform, thereby improving the thermal management efficiency, thereby eliminating the changes in the temperature field inside the device during the desorption and absorption of hydrogen in the magnesium-based hydrogen storage device. The arrangement of the copper magnesium-based hydrogen storage material tray prevents the hydrogen storage material from being compacted due to hydrogen absorption and desorption inside the device, thereby facilitating the loading and unloading of the material, and at the same time preventing the material from expanding the lattice due to hydrogen absorption and desorption, thereby causing stress concentration on the outer wall of the hydrogen storage device, thereby improving the service life and safety of the magnesium-based hydrogen storage device.

[0034] (4) A ventilation pipe is set inside the magnesium-based hydrogen storage device to improve the flow of hydrogen inside the device, allowing hydrogen to reach the inside of the device directly, improving the slow reaction transfer and the phenomenon of inhibited hydrogen absorption / desorption caused by material heating / cooling, thereby effectively improving the hydrogen desorption and absorption process of the magnesium-based hydrogen storage device.

[0035] Instruction Manual

[0036] Figure 1 Schematic diagram of the structure of a magnesium-based hydrogen storage device in an embodiment of the present invention.

[0037] Figure 2 This is a diagram of the internal heat exchange fluid pipeline structure of the magnesium-based hydrogen storage device in an embodiment of the present invention.

[0038] In the figure: 1 hydrogen charging and discharging port, 2-1 to 2-6 heat exchange fluid outlet pipelines, 3-1 to 3-6 heat exchange fluid inlet pipelines, 4 heat exchange fluid pipelines, 5 ventilation pipe, 6 heat storage phase change material sealing box, 7 magnesium-based hydrogen storage material tray, 8 magnesium-based hydrogen storage material. DETAILED DESCRIPTION

[0039] The endpoints and any values in the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the values between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0040] For the convenience of understanding the technical solution, the present invention provides the following embodiments.

[0041] Figure 1 The figure is a structural diagram of the magnesium-based hydrogen storage device in the embodiment of the present invention. During the hydrogen absorption process, hydrogen gas is filled into the interior of the magnesium-based hydrogen storage device through the hydrogen charging and discharging port 1, and after passing through the gas pipe 5, it is directly and evenly distributed inside the magnesium-based hydrogen storage device, ensuring the uniformity of the hydrogen absorption process and preventing the magnesium-based hydrogen storage material 8 near the hydrogen charging and discharging port 1 from absorbing hydrogen first. The magnesium-based hydrogen storage material 8 far from the hydrogen charging and discharging port 1 is inhibited from absorbing hydrogen due to the large amount of heat released by the material that absorbs hydrogen first. At the same time, due to the large amount of heat released during the hydrogen absorption reaction of the magnesium-based hydrogen storage material 8, most of the heat is directly conducted to the heat storage phase change material sealing box 6 through the magnesium-based hydrogen storage material tray 7 and the magnesium-based hydrogen storage material 8, causing the originally solid heat storage phase change material to melt and absorb heat, storing the heat. The remaining heat that cannot be absorbed by the heat storage phase change material sealing box 6 is conducted to the heat exchange fluid pipeline 4 through contact with the magnesium-based hydrogen storage material tray 7. A large amount of high-performance heat-conducting oil at low temperature enters the heat exchange fluid pipeline 4 from the heat exchange fluid inlet pipelines (3-1) to (3-6), and flows out of the magnesium-based hydrogen storage device from the heat exchange fluid outlet pipelines (2-1) to (2-6), taking out the excess heat in time and ensuring the stability of the temperature field inside the magnesium-based hydrogen storage device.

[0042] During the hydrogen release process, the hydrogen absorbed by the magnesium-based hydrogen storage material 8 inside the magnesium-based hydrogen storage device is discharged from the device through the gas pipe 5 and then through the hydrogen charging and discharging port 1, ensuring the uniformity of the hydrogen release process and preventing the magnesium-based hydrogen storage material 8 near the hydrogen charging and discharging port 1 from releasing hydrogen first. The magnesium-based hydrogen storage material 8 far from the hydrogen charging and discharging port 1 is inhibited from releasing hydrogen due to the large amount of heat absorbed by the material that releases hydrogen first. Due to the large amount of heat released during the hydrogen release reaction of the magnesium-based hydrogen storage material 8, the temperature inside the magnesium-based hydrogen storage device drops significantly. The liquid heat storage phase change material inside the previous heat storage phase change material sealing box 6 is cooled and releases the absorbed heat, changing from liquid to solid, and transferring the heat to the magnesium-based hydrogen storage material 8 through the heat storage phase change material sealing box 6 and the magnesium-based hydrogen storage material tray 7, ensuring that the magnesium-based hydrogen storage material 8 is not affected by temperature changes during the hydrogen release process and reducing the hydrogen release performance of the material.

[0043] During the above hydrogen release process, a large amount of high-temperature and high-performance heat-conducting oil enters the heat exchange fluid pipeline 4 from the heat exchange fluid inlet pipelines (3-1) to (3-6), and flows out of the magnesium-based hydrogen storage device from the heat exchange fluid outlet pipelines (2-1) to (2-6). A large amount of heat is timely conducted through the heat exchange fluid pipeline 4 to the magnesium-based hydrogen storage material 8 through the magnesium-based hydrogen storage material tray 7, ensuring the stability of the internal temperature field of the magnesium-based hydrogen storage device and not being affected by the decrease in the internal temperature of the magnesium-based hydrogen storage device caused by the endothermic hydrogen release of the material, thereby affecting the hydrogen release performance of the material. At the same time, since the magnesium-based hydrogen storage material 8 is placed inside the magnesium-based hydrogen storage material tray 7 and a heat storage phase change material sealing box 6 is covered on the upper part, the magnesium-based hydrogen storage material 8 is relatively controlled within a certain area. At the same time, there is a certain gap between the magnesium-based hydrogen storage material tray 7 and the outer wall of the device, so that the expansion generated by the lattice expansion of the magnesium-based hydrogen storage material 8 due to hydrogen absorption and release will not cause local stress concentration, resulting in stress concentration on the outer wall of the magnesium-based hydrogen storage device and endangering the safety of the device. At the same time, since the magnesium-based hydrogen storage material 8 is divided into different regions, the caking phenomenon of the material due to hydrogen absorption and release is not significant, and the influence on the hydrogen absorption and release performance of the magnesium-based hydrogen storage material 8 is not obvious, improving the hydrogen absorption and release performance of the magnesium-based hydrogen storage material 8.

[0044] In the above embodiment, the height-to-diameter ratio of the magnesium-based hydrogen storage device is 3:1, the filling rate of the magnesium-based hydrogen storage material in the magnesium-based hydrogen storage material tray is 80%, the height ratio of the magnesium-based hydrogen storage material to the heat storage phase change material sealing box is 1:2, and the distance between the axis of the heat exchange fluid pipeline and the center of the chassis is 0.5 times the radius of the chassis.

[0045] In the above embodiment, the diameter of the ventilation pipe is 10 mm, the diameter of the heat exchange fluid inlet pipe is 6 mm, and the diameter of the heat exchange fluid outlet pipe is 10 mm.

[0046] In the above embodiment, the phase change material of the heat storage phase change material sealing box is NaNO3 molten salt.

[0047] In the above embodiment, the heat exchange fluid pipeline is composed of 6 heat exchange fluid inlet pipes and heat exchange fluid outlet pipes with the same quantity nested.

[0048] In the above embodiment, most of the hydrogen enters the hydrogen storage and heat storage unit through the ventilation pipe, and the certain gap between the magnesium-based hydrogen storage material tray 7 and the outer wall of the device is only used to prevent the lattice expansion of the hydrogen storage material from deforming the device structure.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat storage type magnesium-based hydrogen storage device for maintaining a stable temperature of a reaction bed, characterized in that: The magnesium-based hydrogen storage device includes a hydrogen charging and discharging port, a heat exchange fluid pipeline, a vent pipe, N hydrogen storage and heat storage units, a metal shell, a chassis and a head; The hydrogen and heat storage unit comprises a magnesium-based hydrogen storage material tray, a magnesium-based hydrogen storage material and a heat storage phase change material sealed box; The hydrogen charging and discharging port is arranged on the sealing head and connected to the flange of the sealing head; The heat exchange fluid pipeline is composed of M heat exchange fluid inlet pipes and heat exchange fluid outlet pipes nested together, the heat exchange fluid inlet pipe is arranged in the heat exchange fluid outlet pipe, the heat exchange fluid pipeline is arranged on a concentric circle with the center of the chassis as the center, the heat exchange fluid pipeline is vertically arranged on the chassis, and the distances between the centers of adjacent heat exchange fluid pipelines on the chassis cross section are equal; The heat exchange fluid inlet pipe has openings on both sides, and the heat exchange fluid outlet pipe has openings on one side, and the openings are arranged on a side close to the chassis. The diameter of the heat exchange fluid inlet pipe is smaller than the diameter of the heat exchange fluid outlet pipe, and the heat exchange fluid outlet pipe is connected to the chassis; The ventilation pipe is arranged at the center of the chassis, is a hollow straight pipe, has a porous wall, and is connected to the chassis; The heat storage phase change material sealed box is arranged on the magnesium-based hydrogen storage material, and the heat storage phase change material sealed box is provided with a circular hole through which the ventilation pipe can pass, and M holes are arranged to pass through the heat exchange fluid pipeline; The center of the magnesium-based hydrogen storage material tray is provided with a circular hole, through which the ventilation pipe can pass, M holes are provided for passing through the heat exchange fluid pipeline, and a plurality of ventilation holes perpendicular to the tray are provided, the bottom layer in the hydrogen storage device is the magnesium-based hydrogen storage material tray and is in contact with the chassis, and the top layer in the hydrogen storage device is the magnesium-based hydrogen storage material tray; The magnesium-based hydrogen storage material is arranged on a magnesium-based hydrogen storage material tray, the magnesium-based hydrogen storage material is provided with a circular hole, through which a vent pipe can pass, M holes are provided through which a heat exchange fluid pipeline is passed, and a plurality of vent holes perpendicular to the tray are also provided; The magnesium-based hydrogen storage material tray, the magnesium-based hydrogen storage material and the heat storage phase change material sealed box are stacked and loaded in the metal shell in sequence from bottom to top; Along the axial direction of the hydrogen storage device, the heat exchange fluid pipeline is higher than the ventilation pipe, and the ventilation pipe is higher than the hydrogen and heat storage unit.

2. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The height-to-diameter ratio of the magnesium-based hydrogen storage device is 2.8-3.1:

1.

3. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The filling rate of the magnesium-based hydrogen storage material in the magnesium-based hydrogen storage material tray is 78%-82%.

4. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The height ratio of the magnesium-based hydrogen storage material and the heat storage phase change material sealed box is 1:1.5-2.

5.

5. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The distance between the axis of the heat exchange fluid pipeline and the center of the chassis is 0.25-0.75 times the radius of the chassis.

6. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The magnesium-based hydrogen storage material releases heat during the process of absorbing hydrogen, and the heat storage phase change material sealed box is liquefied by heat to store heat.

7. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The phase change material of the heat storage phase change material sealed box is molten salt, preferably NaNO3 molten salt or KNO3 molten salt.

8. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The magnesium-based hydrogen storage material tray is made of copper.

9. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The diameter of the ventilation tube is 10-12 mm; The diameter of the heat exchange fluid inlet pipe is 6-8 mm; The diameter of the heat exchange fluid outlet pipe is 10-12 mm.

10. The magnesium-based hydrogen storage device according to claim 1, characterized in that: The M is 4-8.

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