A magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite storage

Abstract

The present invention discloses a magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat, which relates to the field of hydrogen energy and comprises a magnesium-based solid-state hydrogen storage device, a composite heat storage device, heat transfer fins, a vacuum insulation layer, a hydrogen supply device, and a hydrogen use device, wherein the composite heat storage device is wrapped around the outside of the magnesium-based solid-state hydrogen storage device, the heat transfer fins are between the magnesium-based solid-state hydrogen storage device and the composite heat storage device, and the vacuum insulation layer is wrapped around the outside of the composite heat storage device; the composite heat storage device is filled with magnesium oxide and / or calcium oxide and a magnesium-zinc eutectic heat storage alloy pressed in a certain mass ratio; the present invention utilizes the sensible heat of magnesium oxide and / or calcium oxide and the latent heat of the magnesium-zinc eutectic phase change heat storage alloy to construct a composite heat storage module, efficiently stores the heat released when the magnesium-based hydrogen storage material absorbs hydrogen, and supplies heat when the magnesium-based hydrogen storage material releases hydrogen, thereby effectively improving the energy utilization rate of the magnesium-based hydrogen heat storage system.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy, and in particular to a magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat. Background Art

[0002] Hydrogen energy, characterized by its green, low-carbon nature, high gravimetric energy density, and abundant reserves, is a key direction for my country's sustainable development. Hydrogen storage and transportation are key links in the hydrogen energy industry chain, connecting upstream hydrogen production with downstream hydrogen consumption. Efficient, safe, and low-cost hydrogen storage and transportation are bottlenecks in hydrogen energy development. Solid-state hydrogen storage technology offers advantages such as high hydrogen storage density, enhanced safety, low cost, and long storage life.

[0003] Among solid-state hydrogen storage materials, magnesium-based hydrogen storage materials have high mass and volumetric hydrogen storage density (7.6wt%, 110gL -1 ), high safety, storage and transportation at room temperature and pressure, abundant resources and low cost, it is considered to be an important way to achieve large-scale storage and transportation of hydrogen. However, magnesium-based hydrogen storage materials involve large heat changes (~74.7kJ mol -1 When magnesium-based hydrogen storage systems are used, the heat released during hydrogen absorption is not effectively utilized and is easily dissipated, while the dehydrogenation process requires a large amount of heat from an external heat source. This results in low energy efficiency for magnesium-based hydrogen storage systems, hindering their widespread application.

[0004] The study found that Mg 72 Zn 28 Eutectic alloys have a high latent heat of solid-liquid phase transition (153 J g -1 ), high cycle life (~10,000 times), high thermal conductivity (67W m -1 K -1 at 25℃,75W m -1 K -1 At 300℃), its solid-liquid phase transition starting temperature (332℃) is within the working temperature range of magnesium-based hydrogen storage alloys for hydrogen absorption and desorption. By doping some Al into the Mg-51Zn eutectic alloy, the phase with high thermal enthalpy (Mg 69 Zn 28 Al3, Mg 70 Zn 24.9 Al 5.1 ). This type of alloy has great potential to be used in conjunction with magnesium-based solid hydrogen storage materials to achieve efficient use of thermal energy and improve the energy utilization rate of the system. However, the production cost of magnesium-zinc eutectic phase change heat storage alloys is relatively high. Magnesium oxide and calcium oxide are high heat capacities (MgO 37J mol -1 K -1 at 25℃; CaO 42Jmol -1 K -1At 25°C, it is an inexpensive sensible heat storage material. Combining a magnesium-zinc phase-change heat storage alloy with magnesium oxide or calcium oxide to construct a composite heat storage module fully utilizes its sensible and latent heat storage capacity, potentially achieving low-cost, high-efficiency heat storage.

[0005] Therefore, those skilled in the art have devoted themselves to developing a magnesium-based combined hydrogen heat storage system based on a combination of sensible and latent heat storage. By utilizing the sensible heat of magnesium oxide or calcium oxide and the latent heat of a magnesium-zinc eutectic phase-change heat storage alloy, a composite heat storage module is constructed. This efficiently stores the heat released by the magnesium-based hydrogen storage material when it absorbs hydrogen and provides heat when it releases hydrogen. This can effectively improve the energy utilization of the magnesium-based combined hydrogen heat storage system and lay the foundation for the development and application of efficient, safe, and low-energy magnesium-based hydrogen storage systems. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that the heat released during the hydrogen absorption process of the existing magnesium-based solid-state hydrogen storage device is not effectively utilized, the hydrogen release process requires a large amount of heat from an external heat source, and the system energy utilization rate is low; the production cost of magnesium-zinc eutectic phase change heat storage alloy is relatively high; magnesium-based solid-state hydrogen storage devices generally use metal casings such as steel and iron, and the device dissipates serious heat during use.

[0007] To address the above-mentioned technical problems, the present invention provides a magnesium-based hydrogen-heat storage system based on a composite heat storage system of sensible and latent heat. This system utilizes the sensible heat of magnesium oxide or calcium oxide and the latent heat of a magnesium-zinc eutectic phase-change heat storage alloy to construct a composite heat storage module for hydrogen-heat storage. This system efficiently stores the heat released by the magnesium-based hydrogen storage material when it absorbs hydrogen, and rapidly releases the heat when the magnesium-based hydrogen storage material needs heat to release hydrogen, thereby improving the system's energy utilization. When the magnesium-based hydrogen storage material releases heat from hydrogen absorption, the heat is transferred to the composite heat storage module via heat conduction. The magnesium oxide or calcium oxide stores heat through its heat capacity, while the magnesium-zinc eutectic alloy stores heat through melting, achieving efficient heat storage. When the magnesium-based hydrogen storage material needs heat to release hydrogen, the magnesium oxide or calcium oxide releases heat through its heat capacity, while the magnesium-zinc eutectic alloy releases heat through solidification, and the heat is then transferred back to the magnesium-based hydrogen storage material via heat conduction.

[0008] By compressing and compounding a magnesium-zinc eutectic phase-change thermal storage alloy with magnesium oxide or calcium oxide sensible heat storage materials at a specific mass ratio, high thermal storage capacity is ensured while reducing the cost of the thermal storage module. Magnesium oxide and calcium oxide have high heat capacity and are inexpensive. Coating them with the magnesium-zinc eutectic phase-change thermal storage alloy maximizes their heat storage capacity and reduces the cost of the thermal storage module.

[0009] A vacuum insulation layer is designed and constructed on the outermost layer of the magnesium-based solid-state hydrogen storage device to reduce heat dissipation during use. The thermal conductivity of a vacuum is essentially zero, and there is no heat convection in a vacuum. By designing and constructing a vacuum insulation layer on the outermost layer of the magnesium-based solid-state hydrogen storage device, heat dissipation losses caused by heat conduction and convection can be effectively reduced.

[0010] The present invention provides a magnesium-based hydrogen-heat joint storage system based on composite heat storage of sensible heat and latent heat, comprising a magnesium-based solid-state hydrogen storage device 1, a composite heat storage device 2, heat transfer fins 3, a vacuum insulation layer 4, a hydrogen supply device 5, and a hydrogen using device 14, wherein the composite heat storage device 2 is wrapped around the outside of the magnesium-based solid-state hydrogen storage device 1, and the heat transfer fins 3 are between the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2 to enhance thermal conductivity; the vacuum insulation layer 4 is wrapped around the outside of the composite heat storage device 2; the hydrogen supply device 5 and the hydrogen using device 14 are connected to the magnesium-based solid-state hydrogen storage device 1.

[0011] Furthermore, the hydrogen supply device 5 is connected to the magnesium-based solid-state hydrogen storage device 1 through a pressure reducing valve 6, a hydrogen metering device 7, a pressure sensor 8, and a first valve 9;

[0012] Furthermore, the hydrogen device 14 is connected to the magnesium-based solid-state hydrogen storage device 1 through the third valve 13, the back pressure valve 10, the hydrogen metering device 7, the pressure sensor 8, and the first valve 9; or is connected to the magnesium-based solid-state hydrogen storage device 1 through the third valve 13, the vacuum pump 12, the second valve 11, the hydrogen metering device 7, the pressure sensor 8, and the first valve 9;

[0013] Furthermore, the first valve 9 should have a flow regulation function;

[0014] Furthermore, the magnesium-based solid-state hydrogen storage device 1 is filled with a magnesium-nickel-based hydrogen storage alloy;

[0015] Furthermore, the composite heat storage device 2 is filled with magnesium oxide and / or calcium oxide and magnesium-zinc eutectic heat storage alloy pressed in a certain mass ratio, wherein the magnesium oxide and / or calcium oxide is wrapped around the outside of the magnesium-zinc eutectic heat storage alloy.

[0016] Furthermore, the mass ratio of magnesium oxide and / or calcium oxide to the magnesium-zinc eutectic heat storage alloy is between 0.3 and 0.6.

[0017] Furthermore, the composition of the magnesium-zinc eutectic Mg x Zn y Al z , where 67≤x≤72, 23≤y≤28, 0≤Z≤10, x+y+z=100 (x, y, z are atomic ratios).

[0018] Preferably, the composition of the magnesium-zinc eutectic can be Mg 72 Zn 28 , Mg 69 Zn 28 Al3, Mg 70 Zn 24.9 Al 5.1 wait.

[0019] Furthermore, when the magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat of the present invention absorbs hydrogen, the heat released by the magnesium-based solid-state hydrogen storage device 1 is stored by the composite heat storage device 2.

[0020] Furthermore, when the magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat of the present invention releases hydrogen, the composite heat storage device 2 supplies heat to the magnesium-based solid-state hydrogen storage device 1.

[0021] Technical Effects

[0022] 1. The present invention utilizes the sensible heat storage of magnesium oxide or calcium oxide and the latent heat storage of magnesium-zinc eutectic phase change heat storage alloy to realize hydrogen-heat joint storage of magnesium-based solid-state hydrogen storage system, conducts thermal self-sufficiency management, and improves the energy utilization rate of the system.

[0023] 2. The present invention utilizes the sensible heat storage capacity of magnesium oxide or calcium oxide and compounds it with a magnesium-zinc eutectic phase change heat storage alloy to ensure high heat storage capacity and reduce the cost of the heat storage module.

[0024] 3. The present invention utilizes a vacuum insulation layer to achieve low heat dissipation of the magnesium-based solid-state hydrogen storage system and improve the hydrogen-heat storage performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

[0026] Figure 1 Schematic diagram of a magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat according to a preferred embodiment of the present invention;

[0027] Reference numerals: magnesium-based solid-state hydrogen storage device 1, composite heat storage device 2, heat transfer fin 3, vacuum insulation layer 4, hydrogen supply device 5, pressure reducing valve 6, hydrogen metering device 7, pressure sensor 8, first valve 9, back pressure valve 10, second valve 11, vacuum pump 12, third valve 13, hydrogen using device 14

[0028] Figure 2 Schematic diagram of the pressed composite of the magnesium-zinc eutectic phase change heat storage alloy and magnesium oxide / calcium oxide according to a preferred embodiment of the present invention;

[0029] Reference numerals: 1. Mg-Zn eutectic phase change heat storage alloy 2. MgO / CaO. DETAILED DESCRIPTION

[0030] The following describes several preferred embodiments of the present invention with reference to the accompanying drawings to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0031] like Figure 1 As shown, the present invention provides a magnesium-based hydrogen-heat storage system based on composite heat storage of sensible heat and latent heat, comprising a magnesium-based solid-state hydrogen storage device 1, a composite heat storage device 2, heat transfer fins 3, a vacuum insulation layer 4, a hydrogen supply device 5, and a hydrogen using device 14, wherein the composite heat storage device 2 is wrapped around the outside of the magnesium-based solid-state hydrogen storage device 1, and the heat transfer fins 3 are between the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2 to enhance heat conduction; the vacuum insulation layer 4 is wrapped around the outside of the composite heat storage device 2; the hydrogen supply device 5 and the hydrogen using device 14 are connected to the magnesium-based solid-state hydrogen storage device 1.

[0032] The hydrogen supply device 5 is connected to the magnesium-based solid-state hydrogen storage device 1 through a pressure reducing valve 6, a hydrogen metering device 7, a pressure sensor 8, and a first valve 9;

[0033] The hydrogen device 14 is connected to the magnesium-based solid-state hydrogen storage device 1 through the third valve 13, the back pressure valve 10, the hydrogen metering device 7, the pressure sensor 8, and the first valve 9; or is connected to the magnesium-based solid-state hydrogen storage device 1 through the third valve 13, the vacuum pump 12, the second valve 11, the hydrogen metering device 7, the pressure sensor 8, and the first valve 9;

[0034] The first valve 9 should have a flow regulation function;

[0035] The magnesium-based solid-state hydrogen storage device 1 is filled with magnesium-nickel-based hydrogen storage alloy;

[0036] The composite heat storage device 2 is filled with magnesium oxide and / or calcium oxide and magnesium-zinc eutectic heat storage alloy pressed in a certain mass ratio, such as Figure 2 The magnesium oxide and / or calcium oxide is shown wrapped on the outside of the magnesium-zinc eutectic heat storage alloy.

[0037] The mass ratio of the magnesium oxide and / or calcium oxide to the magnesium-zinc eutectic heat storage alloy is between 0.3 and 0.6.

[0038] The composition of the magnesium-zinc eutectic is Mg x Zn y Al z , where 67≤x≤72, 23≤y≤28, 0≤Z≤10, x+y+z=100 (x, y, z are atomic ratios). Preferably, the composition of the magnesium-zinc eutectic can be Mg 72 Zn 28 , Mg 69 Zn 28 Al3, Mg 70 Zn 24.9 Al 5.1 wait.

[0039] Furthermore, in the magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat of the present invention, when hydrogen is absorbed, the heat released by the magnesium-based solid-state hydrogen storage device 1 is stored by the composite heat storage device 2.

[0040] Furthermore, in the magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat of the present invention, when hydrogen is released, the composite heat storage device 2 supplies heat to the magnesium-based solid-state hydrogen storage device 1.

[0041] In a preferred embodiment of the present invention, a magnesium-based hydrogen-heat storage system based on combined sensible and latent heat storage comprises a magnesium-based solid-state hydrogen storage device 1, a composite heat storage device 2, heat transfer fins 3, a vacuum insulation layer 4, a hydrogen supply device 5, a pressure reducing valve 6, a hydrogen metering device 7, a pressure sensor 8, a first valve 9, a backpressure valve 10, a second valve 11, a vacuum pump 12, a third valve 13, and a hydrogen consumption device 14. The first valve 9 should have a flow rate control function. The magnesium-based solid-state hydrogen storage device 1 is filled with a magnesium-nickel-based hydrogen storage alloy, while the composite heat storage device 2 is filled with magnesium oxide and / or calcium oxide and a magnesium-zinc eutectic heat storage alloy compressed at a specific mass ratio between 0.3 and 0.6. Heat transfer fins 3 are used to enhance thermal conductivity between the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2. The devices are preheated by electric heating rods connected to the magnesium-based solid-state hydrogen storage device 1 and / or the composite heat storage device 2.

[0042] When the system needs to absorb hydrogen, the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2 are preheated to 320°C and then heating is stopped. Then, the hydrogen supply device 5 supplies hydrogen, which passes through the pressure reducing valve 6, and then flows through the hydrogen metering device 7, the pressure sensor 8, and the first valve 9 in sequence, and enters the magnesium-based solid-state hydrogen storage device 1 at a constant flow rate and a pressure greater than the platform pressure of the magnesium-based hydrogen storage material. The magnesium-based hydrogen storage material in the magnesium-based solid-state hydrogen storage device 1 undergoes a hydrogen absorption reaction and releases heat, which is conducted to the composite heat storage device 2 through the heat transfer fins 3. The magnesium oxide and / or calcium oxide in the composite heat storage device 2 increases in temperature due to heating, and heat is stored through heat capacity. When the temperature exceeds the melting point of the magnesium-zinc eutectic alloy, the magnesium-zinc eutectic alloy in the composite heat storage device 2 melts through phase change to store heat.

[0043] When the system needs to release hydrogen, the first valve 9 is opened, and the released hydrogen flows through the pressure sensor 8 and the hydrogen metering device 7 in sequence, and flows to the hydrogen-using device 14 through the back-pressure valve 10 and the third valve 13. Since the magnesium-based hydrogen storage material releases hydrogen and absorbs heat, the temperature of the magnesium-based solid-state hydrogen storage device 1 drops. The composite heat storage device 2 releases heat and conducts it to the magnesium-based solid-state hydrogen storage device 1 through the fins to support the heat required to be absorbed during the hydrogen release process. The temperature of the magnesium oxide and / or calcium oxide in the composite heat storage device 2 decreases and releases sensible heat. When the temperature is lower than the solidification point of the magnesium-zinc eutectic alloy, the magnesium-zinc eutectic alloy in the composite heat storage device 2 solidifies through phase change and releases heat. When the dehydrogenation pressure is lower than 1.5 bar, the back-pressure valve 10 is closed, and the vacuum pump 12 and the second valve 11 are turned on to quickly extract the remaining hydrogen for use by the hydrogen-using device 14.

[0044] Example 1

[0045] In this embodiment, a magnesium-based hydrogen-heat storage system based on combined sensible and latent heat storage is described. The system comprises a magnesium-based solid-state hydrogen storage device 1, a composite heat storage device 2, heat transfer fins 3, a vacuum insulation layer 4, a hydrogen supply device 5, a pressure reducing valve 6, a hydrogen metering device 7, a pressure sensor 8, a first valve 9, a backpressure valve 10, a second valve 11, a vacuum pump 12, a third valve 13, and a hydrogen consumption device 14. The first valve 9 should have a flow control function. The magnesium-based solid-state hydrogen storage device 1 is filled with a magnesium-nickel-based hydrogen storage alloy, while the composite heat storage device 2 is filled with magnesium oxide and a magnesium-zinc eutectic heat storage alloy compressed at a specific mass ratio of 0.3. Heat transfer fins 3 are used to enhance thermal conductivity between the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2. The devices are preheated using an electric heating rod connected to the magnesium-based solid-state hydrogen storage device 1 and / or the composite heat storage device 2.

[0046] When the system needs to absorb hydrogen, the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2 are preheated to 320°C and then heating is stopped. Then, the hydrogen supply device 5 supplies hydrogen, which passes through the pressure reducing valve 6, and then flows through the hydrogen metering device 7, the pressure sensor 8, and the first valve 9 in sequence, and enters the magnesium-based solid-state hydrogen storage device 1 at a constant flow rate and a pressure greater than the platform pressure of the magnesium-based hydrogen storage material. The magnesium-based hydrogen storage material in the magnesium-based solid-state hydrogen storage device 1 undergoes a hydrogen absorption reaction and releases heat, which is conducted to the composite heat storage device 2 through the heat transfer fins 3. The magnesium oxide in the composite heat storage device 2 is heated to a higher temperature, and heat is stored through heat capacity. When the temperature exceeds the melting point of the magnesium-zinc eutectic alloy, the magnesium-zinc eutectic alloy in the composite heat storage device 2 melts through phase change to store heat.

[0047] When the system needs to release hydrogen, the first valve 9 is opened, and the released hydrogen flows through the pressure sensor 8 and the hydrogen metering device 7 in sequence, and flows to the hydrogen-using device 14 through the back-pressure valve 10 and the third valve 13. Since the magnesium-based hydrogen storage material absorbs heat when releasing hydrogen, the temperature of the magnesium-based solid-state hydrogen storage device 1 drops. The composite heat storage device 2 releases heat and conducts it to the magnesium-based solid-state hydrogen storage device 1 through the fins to support the heat required to be absorbed during the hydrogen release process. The temperature of the magnesium oxide in the composite heat storage device 2 decreases and releases sensible heat. When the temperature is lower than the solidification point of the magnesium-zinc eutectic alloy, the magnesium-zinc eutectic alloy in the composite heat storage device 2 solidifies through phase change and releases heat. When the dehydrogenation pressure is lower than 1.5 bar, the back-pressure valve 10 is closed, and the vacuum pump 12 and the second valve 11 are turned on to quickly extract the remaining hydrogen for use by the hydrogen-using device 14.

[0048] Example 2

[0049] In this embodiment, a magnesium-based hydrogen-heat storage system based on combined sensible and latent heat storage is described. The system comprises a magnesium-based solid-state hydrogen storage device 1, a composite heat storage device 2, heat transfer fins 3, a vacuum insulation layer 4, a hydrogen supply device 5, a pressure reducing valve 6, a hydrogen metering device 7, a pressure sensor 8, a first valve 9, a backpressure valve 10, a second valve 11, a vacuum pump 12, a third valve 13, and a hydrogen consumption device 14. The first valve 9 should have a flow control function. The magnesium-based solid-state hydrogen storage device 1 is filled with a magnesium-nickel-based hydrogen storage alloy, while the composite heat storage device 2 is filled with calcium oxide and a magnesium-zinc eutectic heat storage alloy compressed at a specific mass ratio of 0.3. Heat transfer fins 3 are used to enhance thermal conductivity between the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2. The devices are preheated using an electric heating rod connected to the magnesium-based solid-state hydrogen storage device 1 and / or the composite heat storage device 2.

[0050] When the system needs to absorb hydrogen, the magnesium-based solid-state hydrogen storage device 1 and the composite heat storage device 2 are preheated to 320°C and then heating is stopped. Then, the hydrogen supply device 5 supplies hydrogen, which passes through the pressure reducing valve 6, then sequentially through the hydrogen metering device 7, the pressure sensor 8, and the first valve 9, and enters the magnesium-based solid-state hydrogen storage device 1 at a constant flow rate and a pressure greater than the platform pressure of the magnesium-based hydrogen storage material. The magnesium-based hydrogen storage material in the magnesium-based solid-state hydrogen storage device 1 undergoes a hydrogen absorption reaction and releases heat, which is conducted to the composite heat storage device 2 through the heat transfer fins 3. The calcium oxide in the composite heat storage device 2 is heated to a higher temperature, and heat is stored through heat capacity. When the temperature exceeds the melting point of the magnesium-zinc eutectic alloy, the magnesium-zinc eutectic alloy in the composite heat storage device 2 melts through phase change to store heat.

[0051] When the system needs to release hydrogen, the first valve 9 is opened, and the released hydrogen flows through the pressure sensor 8 and the hydrogen metering device 7 in sequence, and flows to the hydrogen-using device 14 through the back-pressure valve 10 and the third valve 13. Since the magnesium-based hydrogen storage material absorbs heat when releasing hydrogen, the temperature of the magnesium-based solid-state hydrogen storage device 1 drops. The composite heat storage device 2 releases heat and conducts it to the magnesium-based solid-state hydrogen storage device 1 through the fins to support the heat required to be absorbed during the hydrogen release process. The temperature of the calcium oxide in the composite heat storage device 2 decreases and releases sensible heat. When the temperature is lower than the solidification point of the magnesium-zinc eutectic alloy, the magnesium-zinc eutectic alloy in the composite heat storage device 2 solidifies through phase change and releases heat. When the dehydrogenation pressure is lower than 1.5 bar, the back-pressure valve 10 is closed, and the vacuum pump 12 and the second valve 11 are turned on to quickly extract the remaining hydrogen for use by the hydrogen-using device 14.

[0052] This magnesium-based hydrogen-heat storage system, based on combined sensible and latent heat storage, constructs a sensible and latent heat storage module by compressing and compounding magnesium oxide and / or calcium oxide with a magnesium-zinc eutectic alloy. This ensures heat storage capacity while reducing module costs. It effectively stores heat released during hydrogen absorption by the magnesium-based hydrogen storage material and rapidly supplies it during hydrogen release, achieving efficient hydrogen-heat storage for the magnesium-based solid-state hydrogen storage system. The system's operating energy utilization rate is no less than 90%. This system is easy to implement and has simple and clear operational logic. It addresses the difficulty of low energy utilization in magnesium-based hydrogen storage systems and lays the foundation for the development and application of efficient, safe, and low-energy magnesium-based hydrogen storage systems, with a market size of potentially tens of billions of yuan.

[0053] The preferred embodiments of the present invention have been described in detail above. It should be understood that numerous modifications and variations based on the concepts of the present invention are possible without inventive effort by those skilled in the art. Therefore, any technical solution that can be derived by one skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat, comprising a magnesium-based solid-state hydrogen storage device (1), a composite heat storage device (2), a heat transfer fin (3), a vacuum insulation layer (4), a hydrogen supply device (5), and a hydrogen use device (14), characterized in that: The composite heat storage device (2) is wrapped around the outside of the magnesium-based solid-state hydrogen storage device (1), and the heat transfer fins (3) are between the magnesium-based solid-state hydrogen storage device (1) and the composite heat storage device (2); the vacuum insulation layer (4) is wrapped around the outside of the composite heat storage device (2); the hydrogen supply device (5) and the hydrogen use device (14) are connected to the magnesium-based solid-state hydrogen storage device (1); the composite heat storage device (2) is filled with pressed magnesium oxide and / or calcium oxide and a magnesium-zinc eutectic heat storage alloy, wherein the magnesium oxide and / or calcium oxide are wrapped around the outside of the magnesium-zinc eutectic heat storage alloy.

2. A magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 1, characterized in that: The hydrogen supply device (5) is connected to the magnesium-based solid-state hydrogen storage device (1) via a pressure reducing valve (6), a hydrogen metering device (7), a pressure sensor (8), and a first valve (9).

3. The magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 1 is characterized in that: The hydrogen-using device (14) is connected to the magnesium-based solid-state hydrogen storage device (1) via a third valve (13), a back pressure valve (10), a hydrogen metering device (7), a pressure sensor (8), and a first valve (9); or is connected to the magnesium-based solid-state hydrogen storage device (1) via a third valve (13), a vacuum pump (12), a second valve (11), a hydrogen metering device (7), a pressure sensor (8), and a first valve (9).

4. A magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 2 or claim 3, characterized in that: The first valve (9) should have a flow regulating function.

5. The magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 1 is characterized in that: The magnesium-based solid-state hydrogen storage device (1) is filled with a magnesium-nickel-based hydrogen storage alloy.

6. The magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 1 is characterized in that: The mass ratio of the magnesium oxide and / or calcium oxide to the magnesium-zinc eutectic heat storage alloy is between 0.3 and 0.

6.

7. The magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 1 is characterized in that: The composition of the magnesium-zinc eutectic is Mg x Zn y Al z , where 67≤x≤72, 23≤y≤28, 0≤Z≤10, x+y+z=100.

8. The magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 1 is characterized in that: When the magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat absorbs hydrogen, the heat released by the magnesium-based solid-state hydrogen storage device (1) is stored by the composite heat storage device (2).

9. The magnesium-based hydrogen heat storage system based on sensible heat and latent heat composite heat storage according to claim 3 is characterized in that: When the magnesium-based hydrogen heat storage system based on composite heat storage of sensible heat and latent heat releases hydrogen, the composite heat storage device (2) supplies heat to the magnesium-based solid-state hydrogen storage device (1).

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