Microchannel gradient-boosting magnesium-based hydrogen storage reactor and system

Abstract

A gradient pressure-boosting magnesium-based hydrogen storage reactor equipped with microchannels is provided to improve the reaction rate and heat transfer effect of a tank-type reactor and to enhance the efficiency of hydrogen storage and dehydrogenation. [Solution] The system includes a cylindrical housing, with a first liquid phase chamber and a second liquid phase chamber at each end of the cylindrical housing, and a plurality of heat-conductive separators spaced apart along the axial direction of the cylindrical housing within the cylindrical housing, the heat-conductive separators dividing the inner cavity of the cylindrical housing into a plurality of disk-shaped reactant filling areas spaced apart along the axial direction of the cylindrical housing, the disk-shaped reactant filling areas being filled with a hydrogen storage compound, and a gas phase channel extending axially through the center of the cylindrical housing, the side wall of the gas phase channel being a metal mesh, one end of the gas phase channel being a joint end and the other end of the gas phase channel being a closed end, the metal mesh passing through the disk-shaped reactant filling areas being connected to the gas phase channel.

Description

[Technical Field]

[0001] The present invention relates to hydrogen storage reactors, and more particularly to gradient-boosted magnesium-based hydrogen storage reactors and systems with microchannels. [Background technology]

[0002] Conventional solid-state hydrogen storage reactors mainly include tubular reactors, tank reactors, and disk reactors. Tubular reactors typically have a central hydrogen gas flow, with the hydrogen storage material filling the annular space between the central hydrogen gas flow and the tube wall. Heat exchange between the reactor bed and the heat source / heat sink occurs through the outer surface of the tube wall. Tank reactors have a larger spatial size than tubular reactors, allowing for more metal hydride material to be packed inside. Hydrogen gas can freely enter and leave the reactor through surrounding external filters and inserted piping. The reactor bed of a disk reactor has a flat shape with a length-to-width ratio much smaller than 1. In a typical layout, hydrogen gas flows in and out radially through a screen, simultaneously exchanging heat on the other side. It has a large heat transfer area and a fast reaction rate. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the above-mentioned deficiencies of the prior art, the present invention aims to provide a gradient pressure-boosting magnesium-based hydrogen storage reactor equipped with microchannels, which can improve the reaction rate and heat transfer effect of the tank reactor and increase the efficiency of hydrogen storage and dehydrogenation. Another aim of the present invention is to provide a gradient pressure-boosting magnesium-based hydrogen storage reaction system equipped with microchannels. [Means for solving the problem]

[0004] The technical solution of the present invention is as follows: A gradient pressure-increasing magnesium-based hydrogen storage reactor with microchannels, comprising a cylindrical housing, a first liquid phase chamber and a second liquid phase chamber at both ends of the cylindrical housing, a plurality of heat-conductive separators spaced apart along the axial direction of the cylindrical housing within the cylindrical housing, the heat-conductive separators partitioning the inner cavity of the cylindrical housing into a plurality of disk-shaped reactant filling regions spaced apart along the axial direction of the cylindrical housing, the disk-shaped reactant filling regions being filled with a hydrogen storage compound, and a through hole in the center of the cylindrical housing in the axial direction. a gas phase channel extending through the cylindrical casing; a side wall of the gas phase channel in the cylindrical casing is made of a metal mesh; one end of the gas phase channel is a joint end and the other end of the gas phase channel is a closed end; the disk-shaped reactant filling area is connected to the gas phase channel via the metal mesh; the cylindrical casing is provided with a plurality of heat exchange channels extending axially therethrough around the gas phase channel; both ends of the heat exchange channel are connected to the first liquid phase chamber and the second liquid phase chamber, respectively; and the tube walls of the heat exchange channels are connected to the heat conductive separator.

[0005] Furthermore, the ratio of the thickness of the heat-conductive separator to the thickness of the disc-shaped reactant-packing region is 0.4 to 0.5.

[0006] Furthermore, end plates are provided on both ends of the cylindrical housing, and removable end caps are connected to both ends of the cylindrical housing, with the first liquid phase chamber and the second liquid phase chamber being formed between the end caps and the end plates.

[0007] Furthermore, the end cap constituting the first liquid phase chamber is provided with a heat exchange fluid inlet, and the end cap constituting the second liquid phase chamber is provided with a heat exchange fluid outlet.

[0008] Furthermore, the connection points between the heat exchange channels and the end plates are the inlet and outlet ends of the heat exchange channels, and a filter net is provided at the inlet and outlet ends.

[0009] Furthermore, the mesh of the metal netting is 300 to 400 mesh.

[0010] Furthermore, the hydrogen storage compound has a packing porosity of 0.5 to 0.8.

[0011] Furthermore, an emergency exhaust port is provided at the closed end of the gas phase channel.

[0012] Furthermore, a temperature sensor is provided in the disc-shaped reactant filling area.

[0013] Another technical solution of the present invention is as follows: A gradient pressure-boosting magnesium-based hydrogen storage reaction system with microchannels, comprising: a gradient pressure-boosting magnesium-based hydrogen storage reactor with microchannels, a hydrogen gas source, and a heat exchange fluid storage tank, wherein the heat exchange fluid storage tank is connected to the first liquid phase chamber via a pump to provide heat exchange fluid to the first liquid phase chamber, the second liquid phase chamber is connected to the heat exchange fluid storage tank via a pipe to return the heat exchange fluid to the heat exchange fluid storage tank, and the hydrogen gas source is connected to a joint end of the gas phase channel. [Effects of the Invention]

[0014] Compared with the prior art, the advantages of the technical solution of the present invention are as follows:

[0015] The disc-shaped reactant packing area and the thermally conductive separator layer are spaced apart, and the heat exchange channels run through the entire cylinder, the thermally conductive separator provides a fast heat exchange channel, and the heat exchange channel provides a fast heat exchange channel, this combination significantly improves the overall heat exchange efficiency and allows the system to quickly respond to changes in heat load.

[0016] The disc-shaped reactant packing area is spaced apart by thermally conductive separators, which, combined with the rapid heat transfer through the heat exchange channels, contributes to a uniform temperature distribution over a wide area, reducing local temperature differences and optimizing temperature uniformity throughout the reactor, effectively reducing or eliminating hot spots and protecting the stability and performance of the hydrogen storage material.

[0017] The present invention is applicable to gradient-boosting hydrogen storage, which requires the hydrogen charging pressure to be rapidly increased to a new high value in a small time step size, placing high demands on the reactor's heat exchange capacity and temperature uniformity. If the temperature uniformity of the reaction bed is poor, the initial reaction will have a large temperature gradient. As the hydrogen charging pressure increases, the temperature gradient will further widen, and hydrogen storage alloys with low reaction levels will always react at a low hydrogen absorption rate, making it impossible to achieve rapid hydrogen charging. However, the present invention ensures overall temperature uniformity at all times, thereby improving the overall efficiency of the reactor. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a structural schematic diagram of a gradient-increasing magnesium-based hydrogen storage reactor with microchannels according to an embodiment of the present invention; FIG. [Figure 2] FIG. 2 is a structural schematic diagram of the heat exchange channel distribution. [Figure 3] 1 is a structural schematic diagram of a gradient-increased pressure magnesium-based hydrogen storage reaction system with microchannels according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be further described below with reference to examples, but is not limited thereto.

[0020] As shown in FIGS. 1 and 2 , a gradient-boosting magnesium-based hydrogen storage reactor with microchannels according to an embodiment of the present invention includes a cylindrical housing 1, with end plates connected to both ends to close the housing. A top cap 3 is fixedly connected to the periphery of the top end plate 2 of the cylindrical housing 1 with screws, and a seal is provided at the connection between the top cap 3 and the top end plate 2 with a seal ring. A first liquid chamber 4 is defined in the space between the top cap 3 and the top end plate 2. A heat exchange fluid inlet 5 is provided in the top end plate 3, through which the heat exchange fluid enters the first liquid chamber 4. Similarly, a bottom cap 7 is fixedly connected to the periphery of the bottom end plate 6 of the cylindrical housing 1 with screws, and a seal is provided at the connection between the bottom cap 7 and the bottom end plate 6 with a seal ring. A second liquid chamber 8 is defined in the space between the bottom cap 7 and the bottom end plate 6. The bottom cover 7 is provided with a heat exchange fluid outlet 9, and the heat exchange fluid in the second liquid phase chamber 8 flows out from the heat exchange fluid outlet 9.

[0021] A plurality of heat-conductive separators 10 are provided within the cylindrical casing 1. The heat-conductive separators 10 are disk-shaped, with a diameter corresponding to the inner diameter of the cylindrical casing 1. They are arranged at equal intervals along the axial direction of the cylindrical casing 1, thereby dividing the inner cavity of the cylindrical casing 1 into a plurality of disk-shaped reactant filling regions 11 spaced apart along the axial direction of the cylindrical casing 1. The disk-shaped reactant filling regions 11 and the heat-conductive separators 10 are arranged alternately. A magnesium-based hydrogen storage compound is filled within the disk-shaped reactant filling regions 11, and the ratio of the thickness of the heat-conductive separators 10 to the thickness of the disk-shaped reactant filling regions 11 is 0.4 to 0.5. In this example, the ratio of the thickness of the heat-conductive separators 10 (3 mm) to the thickness of the disk-shaped reactant filling regions 11 (7.2 mm) is 0.42. The thermally conductive separator 10 provides a heat transfer channel during hydrogen absorption and dehydrogenation of the magnesium-based hydrogen storage compound, ensuring temperature uniformity at each location within the disc-shaped reactant-packed region 11 .

[0022] A pipe made of a metal mesh 13 is provided in the center of the cylindrical casing 1 in the axial direction. The pipe made of the metal mesh 13 is a gas phase channel 12, and the mesh of the metal mesh 13 is 300 to 400 mesh. This gas phase channel 12 penetrates from the top to the bottom of the cylindrical casing 1, that is, it penetrates each disk-shaped reactant filling area 11 and the heat-conductive separator 10. The gas phase channel 12 further extends and penetrates the first liquid phase chamber 4 and the second liquid phase chamber 8. As can be easily understood, in the first liquid phase chamber 4 and the second liquid phase chamber 8, the gas phase channel 12 is made of a general tube (not a meshed tube) to ensure separation between the first liquid phase chamber 4 and the second liquid phase chamber 8. The gas phase channel 12 forms a joint end with the upper end cover 3 and a closed end with the lower end cover 7. The disk-shaped reactant filling area 11 is connected to the gas phase channel 12 through a metal mesh 13. The gas phase channel 12 provides a hydrogen flow channel for hydrogen absorption and dehydrogenation of the magnesium-based hydrogen storage compound. To ensure safety, an emergency exhaust port 14 is provided at the closed end of the gas phase channel 12.

[0023] The cylindrical casing 1 further includes a plurality of heat exchange channels 16 formed by heat-conductive metal tubes 15. The heat-conductive metal tubes 15 are arranged along the axial direction of the cylindrical casing 1 and uniformly distributed around the circumferential direction of the gas phase channel 12. For example, in this embodiment, 16 heat exchange channels 16 are arranged, and the heat-conductive metal tubes 15 have an inner diameter of 1.8 mm and a tube wall thickness of 2 mm. Both ends of the heat-conductive metal tubes 15 are connected to the top end plate 2 and the bottom end plate 6 of the cylindrical casing 1, respectively, and both ends of the heat exchange channels 16 are connected to the first liquid chamber 4 and the second liquid chamber 8, respectively. The tube walls of the heat-conductive metal tubes 15 are connected to the heat-conductive separator 10, and a filter screen 17 is provided at the inlet / outlet end formed by connecting to the top end plate 2 to further filter the heat exchange fluid and prevent clogging of the heat exchange channels 16.

[0024] As shown in Figure 3, the components of this embodiment, including the microchannel-equipped gradient-boosting magnesium-based hydrogen storage reactor 100, hydrogen gas source 18, and heat exchange fluid reservoir 19, constitute a microchannel-equipped gradient-boosting magnesium-based hydrogen storage reaction system. The heat exchange fluid reservoir 19 is connected to a pump 20, a flow meter 21, and a first control valve 22, and then to the heat exchange fluid inlet 5 of the microchannel-equipped gradient-boosting magnesium-based hydrogen storage reactor 100 and finally to the first liquid-phase chamber 4 to provide heat exchange fluid to the first liquid-phase chamber 4. The heat exchange fluid outlet 9 is connected to the heat exchange fluid reservoir 19 via a pipe, connecting the second liquid-phase chamber 8 and the heat exchange fluid reservoir 19, allowing the heat exchange fluid to return to the heat exchange fluid reservoir 19. The hydrogen gas source 18 is a hydrogen gas reservoir, and is connected to a second control valve 23 and a three-way valve 24, and then to the joint end of the gas-phase channel 12. The disk-shaped reactant filling area 11 is equipped with a temperature sensor 25, and the system further includes a controller 26 connected to the temperature sensor 25, which controls the flow rate of the heat exchange fluid and the hydrogen gas pressure provided by the hydrogen gas source 18. During actual hydrogen storage, the controller 26 adjusts the hydrogen supply pressure every 10 seconds to achieve the maximum reaction rate until the reaction is complete. The gradient-boosting magnesium-based hydrogen storage reactor 100 with microchannels of the present invention is applied with a gradient-boosting hydrogen filling policy, and the reactor has optimally matched hydrogen pressures at different temperatures. With each hydrogen supply pressure step size, the average thrust of the reactor is significantly enhanced, and the thermal efficiency of the reactor is improved by the gradient-boosting hydrogen filling policy.

Claims

1. A magnesium-based hydrogen storage reactor, comprising: a cylindrical housing, a first liquid phase chamber and a second liquid phase chamber provided at both ends of the cylindrical housing, and a plurality of thermally conductive separators provided at intervals along an axial direction of the cylindrical housing within the cylindrical housing; The heat conductive separator divides the inner cavity of the cylindrical housing into a plurality of disk-shaped reactant filling regions spaced apart along the axial direction of the cylindrical housing, the disk-shaped reactant filling regions are filled with a hydrogen storage compound, a gas phase channel is provided in the center of the cylindrical housing and extends axially therethrough, a side wall of the gas phase channel in the cylindrical housing is made of a metal mesh, one end of the gas phase channel is a joint end, and the other end of the gas phase channel is a closed end; the disk-shaped reactant packing area is connected to the gas phase channel via the metal mesh, the cylindrical housing has a plurality of axially penetrating heat exchange channels provided around the gas phase channel, both ends of the heat exchange channels are connected to the first liquid phase chamber and the second liquid phase chamber, respectively, and the tube walls of the heat exchange channels are connected to the heat conductive separator.

2. 2. The magnesium-based hydrogen storage reactor according to claim 1, wherein the ratio of the thickness of the heat-conductive separator to the thickness of the disc-shaped reactant-filled area is 0.4 to 0.

5.

3. 2. The magnesium-based hydrogen storage reactor according to claim 1, wherein end plates are provided on both ends of the cylindrical housing, removable end covers are connected to both ends of the cylindrical housing, and the first liquid phase chamber and the second liquid phase chamber are formed between the end covers and the end plates.

4. 4. The magnesium-based hydrogen storage reactor according to claim 3, wherein the end cap constituting the first liquid phase chamber is provided with a heat exchange fluid inlet, and the end cap constituting the second liquid phase chamber is provided with a heat exchange fluid outlet.

5. 4. The magnesium-based hydrogen storage reactor according to claim 3, wherein the connection points between the heat exchange channel and the end plate are inlet and outlet ends of the heat exchange channel, and a filtering screen is provided at the inlet and outlet ends.

6. 2. The magnesium-based hydrogen storage reactor according to claim 1, wherein the mesh of the metal net is 300 to 400 mesh.

7. 2. The magnesium-based hydrogen storage reactor according to claim 1, wherein the hydrogen storage compound has a packing porosity of 0.5 to 0.

8.

8. 2. The magnesium-based hydrogen storage reactor according to claim 1, wherein the closed end of the gas phase channel is provided with an emergency exhaust port which is normally closed and which exhausts in an emergency.

9. 2. The magnesium-based hydrogen storage reactor according to claim 1, wherein the disk-shaped reactant filling area is provided with a temperature sensor.

10. A magnesium-based hydrogen storage reaction system, comprising: a magnesium-based hydrogen storage reactor according to any one of claims 1 to 9, a hydrogen gas source, and a heat exchange fluid reservoir tank; the heat exchange fluid storage tank is connected to the first liquid phase chamber via a pump to provide a heat exchange fluid to the first liquid phase chamber; the second liquid phase chamber is connected to the heat exchange fluid storage tank via a pipe to return the heat exchange fluid to the heat exchange fluid storage tank; and the hydrogen gas source is connected to a joint end of the gas phase channel.

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