Hydrogen-induced heating structure design method based on starting hydrogen storage material combination

Abstract

The invention provides a hydrogen-induced heating structure design method based on starting a hydrogen storage material combination. The method comprises the following steps: 1, determining parameters of a functional material bed layer; 2, determining physical property parameters of candidate starting hydrogen storage materials and screening starting hydrogen storage material combinations; and 3, determining parameters of the hydrogen-induced heating structure. The screening requirements need to meet the following three screening requirements: 1, at least one starting hydrogen storage material can be started from room temperature; 2, overlapping exists between the starting temperature and the equilibrium temperature corresponding to the hydrogen absorption operation pressure; and 3, the working temperature ranges of different starting hydrogen storage materials are overlapped to completely cover the room temperature to the starting temperature of the functional material bed layer. The temperature of the obtained hydrogen-induced heating structure can be raised to 270-350 DEG C, and the required temperature raising time is 130-200 s; and the heating depth of the hydrogen-induced heating structure is 1-5mm, so that the functional material bed layer can be quickly started.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen energy storage, specifically relating to a hydrogen-induced heating structure design method based on a combination of hydrogen storage materials. Background Technology

[0002] In laboratory applications of solid-state hydrogen storage materials, only a small amount of the material is used, and the solid-state hydrogen storage bed can be heated quickly and easily. However, in practical applications, due to the large mass and low thermal conductivity of solid-state hydrogen storage materials, conventional high-temperature solid-state hydrogen storage devices face the problem of difficulty and long heating time for the solid-state hydrogen storage bed. This is because existing solid-state hydrogen storage devices use a traditional heat exchange fluid start-up method, which involves heating the entire medium-to-high temperature solid-state hydrogen storage bed to a high temperature using a heat exchange fluid before introducing hydrogen gas for the hydrogen absorption reaction. For example, existing literature 1 (Large scale magnesiumhydride tank coupled with an external heat source, International Journal of Hydrogen Energy, 2012, 37: 9103-9111) uses high-temperature heat transfer oil to heat the MgH2 bed to 240°C before performing the hydrogen absorption operation; and during the subsequent hydrogen absorption reaction, the temperature of the heat transfer oil is also maintained at 240°C to remove the large amount of heat generated by the hydrogen absorption reaction. However, the problem with this type of start-up method based on heat exchange fluid is that the heat exchange fluid requires an additional heating source, which inevitably leads to the solid hydrogen storage device being overly dependent on the external heating source and having poor device independence.

[0003] To address the dependence of heat exchange fluid start-up methods on external heating sources, the inventors of this invention have proposed using solid hydrogen storage initiation materials to create an initiation structure, thereby enabling high-temperature solid hydrogen storage devices and their operation methods to start without an external heat source. The basic principle is that the solid hydrogen storage material absorbs hydrogen and releases heat within the storage device, achieving the effect of eliminating the need for external energy supply, thus reducing the need for external energy supply devices and ultimately simplifying the system structure and reducing its volume. However, in implementing the above technical solution, a new unresolved technical problem exists—when using solid hydrogen storage materials for heating, it is difficult to effectively obtain the operating temperature that reaches the working temperature of the solid hydrogen storage material, i.e., it is difficult to effectively initiate the reaction of the solid hydrogen storage material, resulting in a slow start-up speed or even failure to start the solid hydrogen storage material. Summary of the Invention

[0004] The purpose of this invention is to provide a design method for a hydrogen-induced heating structure based on a combination of hydrogen storage materials. To achieve this objective, it is necessary to address the issue of matching the operating temperatures of the solid-state hydrogen storage initiating material and the solid-state hydrogen storage functional material, i.e., to use a combination of multiple solid-state hydrogen storage materials to create the hydrogen-induced heating structure.

[0005] However, according to the inventors' research, not any arbitrary combination of solid hydrogen storage materials can initiate the reaction of the solid hydrogen storage functional material; that is, the connection and matching between the solid hydrogen storage initiating material and the operating temperature of the solid hydrogen storage functional material are crucial. Therefore, the technical problem to be solved by this invention is to design a hydrogen-induced heating structure that matches and connects with the operating temperature of the solid hydrogen storage functional material to accelerate the activation of the solid hydrogen storage functional material.

[0006] Specifically, the inventive principle of this invention is as follows:

[0007] 1. Select a combination of start-up hydrogen storage materials with a suitable operating temperature range for use in the hydrogen-heated structure. Through the stepwise reaction and exothermic reaction of start-up hydrogen storage materials at different operating temperatures within the hydrogen-heated structure, the temperature of the hydrogen-heated structure is increased, thereby achieving the matching and connection between the temperature of the hydrogen-heated structure and the operating temperature of the functional material bed.

[0008] 2. Calculate the key parameters for starting the hydrogen storage material. Based on the law of conservation of energy and the parameters of the functional material bed, determine the key parameters such as the ratio, total mass, and total volume of the hydrogen storage material in the hydrogen-heated structure to ensure that the hydrogen-heated structure can achieve rapid start-up of the functional material bed.

[0009] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] A method for designing a hydrogen-induced heating structure based on a combination of hydrogen storage materials includes the following steps:

[0011] Step 1: Determining the parameters of the functional material bed, including start-up temperature, thermal diffusivity, structure, and operating conditions;

[0012] Step 2: Determining the physical properties of candidate start-up hydrogen storage materials and screening start-up hydrogen storage material combinations. First, based on the start-up temperature of the functional material bed, solid hydrogen storage materials with a hydrogen storage temperature range from room temperature to the start-up temperature are collected to obtain the equilibrium pressure of the solid hydrogen storage materials. Then, according to the van't Hoff equation (2), the ln P of the existing solid hydrogen storage materials is obtained. eq -10 3 / T curve, ln P of solid hydrogen storage materials eq With 10 3 / T shows a linear relationship. Finally, based on the existing lnP of solid-state hydrogen storage materials... eq -103 The / T curve is used to screen solid hydrogen storage materials that meet the requirements. Based on the screening requirements, the solid hydrogen storage materials that meet the requirements are used as the start-up hydrogen storage material combination, and the parameters of the screened start-up hydrogen storage materials are determined.

[0013]

[0014] In formula (2), P eq P is the equilibrium pressure for the hydrogen absorption reaction. ref The reference pressure is ΔH, the enthalpy change of the reaction is ΔH, the gas constant is R, the temperature is T, and the entropy change of the reaction is ΔS.

[0015] Step 3: Determining the parameters of the hydrogen-induced heating structure. Based on the hydrogen storage material combination selected in Step 2, calculate the key parameters of the hydrogen storage material for starting the hydrogen-induced heating structure.

[0016] In step 1, the functional bed start-up temperature is the temperature at which the functional bed enters the continuous rapid response stage;

[0017] The formula for calculating the thermal diffusivity is shown in formula (1).

[0018]

[0019] In formula (1), α is the thermal diffusivity, λ is the thermal conductivity, ρ is the density, and C is the thermal conductivity. p Specific heat capacity.

[0020] In step 2, the screening requirements must meet the following three criteria.

[0021] Requirement 1: At least one hydrogen storage material must be able to start from room temperature, i.e., be able to carry out a continuous and rapid hydrogen absorption reaction at room temperature;

[0022] Requirement 2: When there are two or more start-up hydrogen storage materials, the operating temperature ranges of the different start-up hydrogen storage materials, i.e., there is an overlap between the start-up temperature and the equilibrium temperature corresponding to the hydrogen absorption operating pressure;

[0023] Requirement 3: The combined operating temperature ranges of different start-up hydrogen storage materials should completely cover the period from room temperature to the start-up temperature of the functional material bed.

[0024] In step 3, the key parameters are the ratio of the hydrogen storage material to start-up, the total mass of the hydrogen storage material to start-up, and the total volume of the hydrogen storage material to start-up.

[0025] The principle for determining the structural parameters of hydrogen-induced heating is that the heat released by the hydrogen storage material during startup can raise the temperature of the hydrogen storage material combination and some functional bed layers, and the temperature rise range is from room temperature to the upper limit of the operating temperature range of the hydrogen storage material.

[0026] The formula for calculating the mass of the hydrogen storage material is shown in formula (3).

[0027]

[0028] In formula (3), m is the mass of the starting hydrogen storage material; i represents the i-th type of starting hydrogen storage material; χ represents the actual hydrogen storage capacity of the starting hydrogen storage material; M H2 The molar mass of hydrogen is represented by ΔH; the enthalpy of hydrogen absorption during startup is represented by ΔH; the operating temperature range of the startup hydrogen storage material is represented by ΔT; n is the number of types of startup hydrogen storage materials in the combination of startup hydrogen storage materials; C p Indicates the specific heat capacity of the hydrogen storage material at startup; m fm For partial functional bed quality; C p,fm α is the specific heat capacity of the functional bed; α is the adjustment coefficient, with a value range of 0-1. The specific value is adjusted according to the number of start-up hydrogen storage materials that can stably absorb hydrogen within a certain operating temperature range. The more types of start-up hydrogen storage materials that can stably absorb hydrogen within a certain operating temperature range, the smaller the value of α.

[0029] The number of types of hydrogen storage materials used in the initial setup is equal to the number of formulas. By solving the equations simultaneously, the ratio of hydrogen storage materials used in the initial setup can be calculated.

[0030] The total mass of the solid hydrogen storage material in the hydrogen-heated structure is determined by its heating depth. The heating depth of the hydrogen-heated structure is determined by the thermal diffusivity of the functional material bed. The heating depth of the hydrogen-heated structure ranges from 1 to 15 mm.

[0031] The volume of the hydrogen-heated structure was calculated by initiating the total mass of the hydrogen storage material, the material density, and the material porosity.

[0032] The hydrogen-induced heating structure can raise the temperature to 270-350℃, with a heating time of 130-200s; the heating depth of the hydrogen-induced heating structure is 1-5mm, which enables rapid start-up of functional material beds.

[0033] When the functional material is a Mg hydrogen storage material

[0034] In step 1, the starting temperature of the functional material bed is 300-350℃, and the density is 1800-2400 kg / m³. 3 Its specific heat capacity is 500-3000 J / (kg·K), and its thermal diffusivity is 1.0×10⁻⁶. -5 -1.0×10 -8 m 2 / s, the functional material bed is a cylindrical powder briquette with a diameter of 15cm, a height of 5cm, a porosity of 0.5, and a hydrogen absorption operating pressure of 1-6MPa;

[0035] In step 2, the screening range for hydrogen storage materials is expanded, with LaNi5 and LaNi5 being the candidate hydrogen storage materials. 4.25 Al 0.75 ZrMn2, Ti 1.05 Y 0.02 Zr 0.03 Fe 0.8 Mn 0.2 Mg 90 Ni 10 Among them, the start-up hydrogen storage material combination that meets the above screening requirements is LaNi5 and LaNi. 4.25 Al 0.75 and ZrMn2,

[0036] The density of LaNi5 initial hydrogen storage material is 8200 kg / m³. 3 It has a specific heat capacity of 419 J / (kg·K), a hydrogen storage capacity of 1.38 wt.%, a reaction enthalpy of 30.1 kJ / mol H2, and an operating temperature range of room temperature to 110℃.

[0037] LaNi 4.25 Al 0.75 The starting density of the hydrogen storage material is 7590 kg / m³. 3 It has a specific heat capacity of 419 J / (kg·K), a hydrogen storage capacity of 0.98 wt%, a reaction enthalpy of 41.51 kJ / mol H2, and an operating temperature range of 110℃ to 185℃.

[0038] The density of ZrMn2 hydrogen storage material is 7100 kg / m³. 3 It has a specific heat capacity of 355 J / (kg·K), a hydrogen storage capacity of 1.57 wt%, a reaction enthalpy of 43.29 kJ / mol H2, and an operating temperature range of 185℃ to 330℃.

[0039] In step 3, when the functional material bed is a cylindrical Mg hydrogen storage material, the starting hydrogen storage material is LaNi5 or LaNi5. 4.25 Al 0.75 When combined with ZrMn2,

[0040] First, the hydrogen-induced heating structure is disc-shaped with a diameter of 15cm. The hydrogen-induced heating structure is placed under the functional material bed and is in close contact with the functional material bed. The function of the hydrogen-induced heating structure is to provide heat to the functional material bed only from the top bottom of the disc, and the remaining surfaces of the hydrogen-induced heating structure should minimize heat loss.

[0041] Then, LaNi5 and LaNi 4.25 Al 0.75 Substituting the physical properties of the three start-up hydrogen storage materials, LaNi5 and LaNi2, into formula (3), we obtain the results.4.25 Al 0.75 The mass ratio of ZrMn2 to ZrMn2 is 0.17:0.21:0.62, and the adjustment coefficients are α1 = 0.5, α2 = 0.3, and α3 = 1.0.

[0042] Finally, based on the thermal diffusivity of the functional material bed, the heating depth of the hydrogen-induced heating structure is determined to be 1-5 mm near the hydrogen-induced heating structure, and the total mass of the hydrogen storage material within the hydrogen-induced heating structure is determined to be 100-300 g, with a total volume of 50-150 cm³. 3 .

[0043] After experimental testing, the technical effects of this invention show that the hydrogen-induced heating structure can heat up to 270-350°C within 150 seconds, enabling rapid start-up of the functional material bed.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] 1. This invention proposes a hydrogen-induced heating structure design method based on a combination of hydrogen storage materials for initiation. By selecting a combination of hydrogen storage materials for initiation with a suitable operating temperature and reacting with hydrogen, the temperature of the hydrogen-induced heating structure can be raised to the temperature required for the functional material bed to start up. This reduces the dependence of the functional material bed on external heating sources for temperature rise.

[0046] 2. By calculating the internal proportions, total mass, and total volume of the hydrogen-heated structure, the hydrogen-heated structure can be rapidly heated to the temperature required for the functional material bed to start up, thereby improving the operating efficiency of the hydrogen storage device. Attached Figure Description

[0047] Figure 1 ln P, a candidate start-up hydrogen storage material for Example 1 eq -10 3 / T curve;

[0048] Figure 2 The graph shows the temperature change of the hydrogen-heated structure over time during the startup process of Example 1. Detailed Implementation

[0049] The present invention will be further described in detail through embodiments and with reference to the accompanying drawings, but this is not intended to limit the scope of the invention.

[0050] Example 1

[0051] A method for designing a hydrogen-induced heating structure based on a combination of hydrogen storage materials includes the following steps:

[0052] Step 1: Determining the parameters of the functional material bed, including start-up temperature, thermal diffusivity, structure, and operating conditions;

[0053] The start-up temperature of the functional bed is the temperature at which the functional bed enters the continuous rapid response phase;

[0054] The formula for calculating the thermal diffusivity is shown in formula (1).

[0055]

[0056] In formula (1), α is the thermal diffusivity, λ is the thermal conductivity, ρ is the density, and C is the thermal conductivity. p Specific heat capacity;

[0057] When the functional material is a Mg hydrogen storage material, the start-up temperature of the functional material bed is 300℃ and the density is 1800 kg / m³. 3 Its specific heat capacity is 1545 J / (kg·K), and its thermal diffusivity is 3.45 × 10⁻⁶. -7 m 2 / s, the functional material bed is a cylindrical powder briquette with a diameter of 15cm, a height of 5cm, a porosity of 0.5, and a hydrogen absorption operating pressure of 3MPa;

[0058] Step 2: Determining the physical properties of candidate start-up hydrogen storage materials and screening start-up hydrogen storage material combinations. First, based on the start-up temperature of the functional material bed, solid hydrogen storage materials with a hydrogen storage temperature range from room temperature to the start-up temperature are collected to obtain the equilibrium pressure of the solid hydrogen storage materials. Then, according to the van't Hoff equation (2), the ln P of the existing solid hydrogen storage materials is obtained. eq -10 3 / T curve, ln P of solid hydrogen storage materials eq With 10 3 / T shows a linear relationship, such as Figure 1 As shown, finally, based on the existing solid-state hydrogen storage material ln P eq -10 3 The / T curve is used to screen solid hydrogen storage materials that meet the requirements. Based on the screening requirements, the solid hydrogen storage materials that meet the requirements are used as the start-up hydrogen storage material combination, and the parameters of the screened start-up hydrogen storage materials are determined.

[0059]

[0060] In formula (2), P eq P is the equilibrium pressure for the hydrogen absorption reaction. ref The reference pressure is ΔH, the enthalpy change of the reaction is ΔH, the gas constant is R, the temperature is T, and the entropy change of the reaction is ΔS.

[0061] The screening requirements must meet the following three criteria:

[0062] Requirement 1: At least one hydrogen storage material must be able to start from room temperature, i.e., be able to carry out a continuous and rapid hydrogen absorption reaction at room temperature;

[0063] Requirement 2: When there are two or more start-up hydrogen storage materials, the operating temperature ranges of the different start-up hydrogen storage materials, i.e., there is an overlap between the start-up temperature and the equilibrium temperature corresponding to the hydrogen absorption operating pressure;

[0064] Requirement 3: The combined operating temperature ranges of different start-up hydrogen storage materials should completely cover the period from room temperature to the start-up temperature of the functional material bed.

[0065] Specific embodiment 1 starts the screening range of hydrogen storage materials, that is, the candidate hydrogen storage materials are LaNi5 and LaNi 4.25 Al 0.75 ZrMn2, Ti 1.05 Y 0.02 Zr 0.03 Fe 0.8 Mn 0.2 Mg 90 Ni 10 Among them, the start-up hydrogen storage material combination that meets the above screening requirements is LaNi5 and LaNi. 4.25 Al 0.75 and ZrMn2,

[0066] The density of LaNi5 initial hydrogen storage material is 8200 kg / m³. 3 It has a specific heat capacity of 419 J / (kg·K), a hydrogen storage capacity of 1.38 wt.%, a reaction enthalpy of 30.1 kJ / mol H2, and an operating temperature range of room temperature to 110℃.

[0067] LaNi 4.25 Al 0.75 The starting density of the hydrogen storage material is 7590 kg / m³. 3 It has a specific heat capacity of 419 J / (kg·K), a hydrogen storage capacity of 0.98 wt%, a reaction enthalpy of 41.51 kJ / mol H2, and an operating temperature range of 110℃ to 185℃.

[0068] The density of ZrMn2 hydrogen storage material is 7100 kg / m³. 3 It has a specific heat capacity of 355 J / (kg·K), a hydrogen storage capacity of 1.57 wt%, a reaction enthalpy of 43.29 kJ / mol H2, and an operating temperature range of 185℃ to 330℃.

[0069] Step 3: Determination of hydrogen-induced heating structure parameters. Based on the hydrogen storage material combination selected in Step 2, calculate the key parameters of the hydrogen storage material for starting the hydrogen-induced heating structure.

[0070] The key parameters are the ratio of the hydrogen storage material for startup, the total mass of the hydrogen storage material for startup, and the total volume of the hydrogen storage material for startup.

[0071] The principle for determining the parameters of the hydrogen-induced heating structure is that the heat released by the hydrogen storage material can raise the temperature of the hydrogen storage material combination and some functional bed layers, and the temperature rise range is from room temperature to the upper limit of the working temperature range of the hydrogen storage material.

[0072] The formula for calculating the mass of the hydrogen storage material used for startup is shown in formula (3).

[0073]

[0074] In formula (3), m is the mass of the starting hydrogen storage material; i represents the i-th type of starting hydrogen storage material; χ represents the actual hydrogen storage capacity of the starting hydrogen storage material; M H2 The molar mass of hydrogen is represented by ΔH; the enthalpy of hydrogen absorption during startup is represented by ΔH; the operating temperature range of the startup hydrogen storage material is represented by ΔT; n is the number of types of startup hydrogen storage materials in the combination of startup hydrogen storage materials; C p Indicates the specific heat capacity of the hydrogen storage material at startup; m fm For partial functional bed quality; C p,fm α is the specific heat capacity of the functional bed; α is the adjustment coefficient, with a value range of 0-1. The specific value is adjusted according to the number of start-up hydrogen storage materials that can stably absorb hydrogen within a certain operating temperature range. The more types of start-up hydrogen storage materials that can stably absorb hydrogen within a certain operating temperature range, the smaller the value of α.

[0075] The number of types of hydrogen storage materials used in the initial setup is equal to the number of formulas. By solving the equations simultaneously, the ratio of hydrogen storage materials used in the initial setup can be calculated.

[0076] The total mass of the solid hydrogen storage material in the hydrogen-induced heating structure is determined according to its heating depth. The heating depth of the hydrogen-induced heating structure is determined according to the thermal diffusivity of the functional material bed. The heating depth of the hydrogen-induced heating structure ranges from 1 to 15 mm.

[0077] The volume of the hydrogen-heated structure is calculated by taking into account the total mass of the hydrogen storage material, the material density, and the material porosity.

[0078] In specific embodiment 1, when the functional material bed is a cylindrical Mg hydrogen storage material, the starting hydrogen storage material is LaNi5 or LaNi 4.25 Al 0.75 When combined with ZrMn2,

[0079] First, the hydrogen-induced heating structure is disc-shaped with a diameter of 15cm. The hydrogen-induced heating structure is placed under the functional material bed and is in close contact with the functional material bed. The function of the hydrogen-induced heating structure is to provide heat to the functional material bed only from the top bottom of the disc, and the remaining surfaces of the hydrogen-induced heating structure should minimize heat loss.

[0080] Then, LaNi5 and LaNi 4.25 Al 0.75 Substituting the physical properties of the three start-up hydrogen storage materials, LaNi5 and LaNi2, into formula (3), we obtain the results. 4.25 Al 0.75 The mass ratio of ZrMn2 to ZrMn2 is 0.17:0.21:0.62, and the adjustment coefficients are α1 = 0.5, α2 = 0.3, and α3 = 1.0.

[0081] Finally, based on the thermal diffusivity of the functional material bed, the heating depth of the hydrogen-induced heating structure is determined to be 3 mm near the hydrogen-induced heating structure. The total mass of the hydrogen storage material within the hydrogen-induced heating structure is determined to be 200 g, and the total volume is 90 cm³. 3 .

[0082] To demonstrate that the method described in this invention can activate the functional bed, hydrogen absorption tests were conducted on the Mg hydrogen storage material. The test results are as follows: Figure 2 As shown, the hydrogen-induced heating structure can be heated to 300℃ in 150s; the heating depth of the hydrogen-induced heating structure is 3mm, which enables rapid start-up of the functional material bed.

[0083] To demonstrate the effectiveness of the hydrogen-induced heating structure design method for starting up hydrogen storage material combinations, Comparative Example 1 and Comparative Example 2 are provided, showing the technical solutions for randomly selecting solid hydrogen storage materials as the starting up hydrogen storage material combinations without specific requirements.

[0084] Specifically, Comparative Example 1 uses only LaNi5 and LaNi 4.25 Al 0.75 As a starting hydrogen storage material combination, i.e. a starting hydrogen storage material combination when ZrMn2 is lacking;

[0085] Comparative Example 2 specifically uses only LaNi5 and ZrMn2 as the starting hydrogen storage material combination, i.e., LaNi is missing. 4.25 Al 0.75 The combination of hydrogen storage materials for startup.

[0086] Comparative Example 1

[0087] A method based on LaNi5 and LaNi 4.25 Al 0.75 The hydrogen-induced heating structure of the hydrogen storage material combination is referred to as the medium-low temperature hydrogen storage material combination.

[0088] Hydrogen absorption test results of Mg hydrogen storage material in medium and low temperature hydrogen storage material combination are as follows: Figure 2 As shown, the hydrogen-induced heating structure can only raise the temperature to 259.5℃, meaning it cannot reach temperatures above 300℃. Therefore, the combination of medium- and low-temperature hydrogen storage materials cannot achieve the start-up of the functional material bed. This is because the combination lacks ZrMn2 as a start-up hydrogen storage material; therefore, the highest temperature corresponding to the hydrogen absorption pressure is only 259.5℃, and it cannot reach higher temperatures.

[0089] Comparative Example 2

[0090] A hydrogen-induced heating structure based on a combination of LaNi5 and ZrMn2 hydrogen storage materials is described, referred to as a high-low temperature hydrogen storage material combination.

[0091] Hydrogen absorption test results of Mg hydrogen storage material with high and low temperature hydrogen storage material combination are as follows: Figure 2 As shown, the hydrogen-induced heating structure cannot reach a temperature above 300°C within 180 seconds. Therefore, although the high- and low-temperature hydrogen storage material combination can achieve the startup of the functional material bed, the required time exceeds the application requirements, meaning that rapid startup of the functional material bed cannot be achieved. This is because the high- and low-temperature hydrogen storage material combination lacks LaNi... 4.25 Al 0.75 As a starting hydrogen storage material, only LaNi5 can rapidly and stably absorb hydrogen, while ZrMn2, which has a higher hydrogen absorption temperature, is difficult to achieve the rapid and stable hydrogen absorption stage.

[0092] Therefore, as can be seen from Comparative Examples 1 and 2, the lack of any component in the hydrogen storage material combination will prevent the functional material bed from being started or started up quickly.

[0093] To demonstrate the impact of the proportions of each component in the hydrogen storage material assembly, i.e., the hydrogen-induced heating structure design method, on the ability to achieve rapid heating to the start-up temperature, Comparative Examples 3 and 4 are provided.

[0094] Specifically, Comparative Example 3 involves reducing the mass proportion of LaNi5, a hydrogen storage material for low-temperature startup, while increasing the mass proportion of ZrMn2, a hydrogen storage material for high-temperature startup.

[0095] Specifically, Comparative Example 4 involves increasing the mass proportion of LaNi5, the hydrogen storage material for low-temperature startup, while reducing the mass proportion of ZrMn2, the hydrogen storage material for high-temperature startup.

[0096] Comparative Example 3

[0097] A method based on LaNi5 and LaNi 4.25 Al 0.75 The hydrogen-induced heating structure of the hydrogen storage material combination with a mass ratio of ZrMn2 of 0.02:0.21:0.77 is referred to as the low-temperature hydrogen storage material combination.

[0098] Hydrogen absorption test results of Mg hydrogen storage material with low-temperature hydrogen storage material combination are as follows: Figure 2 As shown, the hydrogen-induced heating structure cannot reach a temperature above 300°C within 180 seconds. Therefore, although a combination of low-temperature hydrogen storage materials can enable the startup of the functional material bed, the required time exceeds the application requirements, meaning that rapid startup of the functional material bed cannot be achieved. This is because the mass percentage of the LaNi5-based hydrogen storage material for startup is low, resulting in a slow initial heating rate of the hydrogen-induced heating structure.

[0099] Comparative Example 4

[0100] A method based on LaNi5 and LaNi 4.25 Al 0.75 The hydrogen-induced heating structure of the hydrogen storage material combination with a mass ratio of ZrMn2 of 0.40:0.21:0.39 is referred to as the multi-low temperature hydrogen storage material combination.

[0101] Hydrogen absorption test results of Mg hydrogen storage material with multiple low-temperature hydrogen storage material combinations are as follows: Figure 2 As shown, the hydrogen-induced heating structure cannot reach a temperature above 300°C within 180 seconds. Therefore, although the combination of multiple low-temperature hydrogen storage materials can enable the startup of the functional material bed, the required time exceeds the application requirements, meaning that rapid startup of the functional material bed cannot be achieved. This is because the mass proportion of ZrMn2 in the startup hydrogen storage material is low, and the heating rate of the hydrogen-induced heating structure is slow in the later stages.

[0102] Therefore, as can be seen from Comparative Examples 3 and 4, changing the proportions of each component in the hydrogen storage material combination does not enable the functional material bed to start up or start up quickly.

Claims

1. A method for designing a hydrogen-induced heating structure based on a combination of hydrogen storage materials, characterized in that... Includes the following steps: Step 1: Determining the parameters of the functional material bed, including start-up temperature, thermal diffusivity, structure, and operating conditions; Step 2: Determining the physical properties of candidate start-up hydrogen storage materials and screening the combination of start-up hydrogen storage materials. First, based on the start-up temperature of the functional material bed, solid hydrogen storage materials with a hydrogen storage temperature range from room temperature to the start-up temperature are collected to obtain the equilibrium pressure of the solid hydrogen storage materials. Then, according to the van't Hoff equation (2), the lnP of the existing solid hydrogen storage materials is obtained. eq -10 3 / T curve, ln P of solid hydrogen storage materials eq With 10 3 / T shows a linear relationship. Finally, based on the existing solid hydrogen storage materials, ln P eq -10 3 The / T curve is used to screen solid hydrogen storage materials that meet the requirements. Based on the screening requirements, the solid hydrogen storage materials that meet the requirements are used as the start-up hydrogen storage material combination, and the parameters of the screened start-up hydrogen storage materials are determined. In formula (2), P eq P is the equilibrium pressure for the hydrogen absorption reaction. ref The reference pressure is ΔH, the enthalpy change of the reaction is ΔH, the gas constant is R, the temperature is T, and the entropy change of the reaction is ΔS. Step 3: Determining the parameters of the hydrogen-induced heating structure. Based on the hydrogen storage material combination selected in Step 2, calculate the key parameters of the hydrogen storage material for starting the hydrogen-induced heating structure.

2. The hydrogen-induced heating structure design method as described in claim 1, characterized in that: In step 1, the functional bed start-up temperature is the temperature at which the functional bed enters the continuous rapid response stage; The formula for calculating the thermal diffusivity is shown in formula (1). In formula (1), α is the thermal diffusivity, λ is the thermal conductivity, ρ is the density, and C is the thermal conductivity. p Specific heat capacity.

3. The hydrogen-induced heating structure design method as described in claim 1, characterized in that: In step 2, the screening requirements must meet the following three criteria. Requirement 1: At least one hydrogen storage material must be able to start from room temperature, i.e., be able to carry out a continuous and rapid hydrogen absorption reaction at room temperature; Requirement 2: When there are two or more start-up hydrogen storage materials, the operating temperature ranges of the different start-up hydrogen storage materials, i.e., there is an overlap between the start-up temperature and the equilibrium temperature corresponding to the hydrogen absorption operating pressure; Requirement 3: The combined operating temperature ranges of different start-up hydrogen storage materials should completely cover the period from room temperature to the start-up temperature of the functional material bed.

4. The hydrogen-induced heating structure design method as described in claim 1, characterized in that: In step 3, the key parameters are the ratio of the hydrogen storage material to start-up, the total mass of the hydrogen storage material to start-up, and the total volume of the hydrogen storage material to start-up. The principle for determining the structural parameters of hydrogen-induced heating is that the heat released by the hydrogen storage material during startup can raise the temperature of the hydrogen storage material combination and some functional bed layers, and the temperature rise range is from room temperature to the upper limit of the operating temperature range of the hydrogen storage material. The formula for calculating the mass of the hydrogen storage material is shown in formula (3). In formula (3), m is the mass of the starting hydrogen storage material; i represents the i-th type of starting hydrogen storage material; χ represents the actual hydrogen storage capacity of the starting hydrogen storage material; M H2 The molar mass of hydrogen is represented by ΔH; the enthalpy of hydrogen absorption during startup is represented by ΔH; the operating temperature range of the startup hydrogen storage material is represented by ΔT; n is the number of types of startup hydrogen storage materials in the combination of startup hydrogen storage materials; C p Indicates the specific heat capacity of the hydrogen storage material at startup; m fm For partial functional bed quality; C p,fm α is the specific heat capacity of the functional bed; α is the adjustment coefficient, with a value range of 0-1. The specific value is adjusted according to the number of start-up hydrogen storage materials that can stably absorb hydrogen within a certain operating temperature range. The more types of start-up hydrogen storage materials that can stably absorb hydrogen within a certain operating temperature range, the smaller the value of α. The number of types of hydrogen storage materials used in the initial setup is equal to the number of formulas. By solving the equations simultaneously, the ratio of hydrogen storage materials used in the initial setup can be calculated. The total mass of the solid hydrogen storage material in the hydrogen-heated structure is determined by its heating depth. The heating depth of the hydrogen-heated structure is determined by the thermal diffusivity of the functional material bed. The heating depth of the hydrogen-heated structure ranges from 1 to 15 mm. The volume of the hydrogen-heated structure was calculated by initiating the total mass of the hydrogen storage material, the material density, and the material porosity.

5. The hydrogen-induced heating structure design method as described in claim 1, characterized in that: The hydrogen-induced heating structure can raise the temperature to 270-350℃, with a heating time of 130-200s; the heating depth of the hydrogen-induced heating structure is 1-5mm, which enables rapid start-up of functional material beds.

6. The hydrogen-induced heating structure design method as described in claim 1, characterized in that: When the functional material is a Mg hydrogen storage material In step 1, the starting temperature of the functional material bed is 300-350℃, and the density is 1800-2400 kg / m³. 3 Its specific heat capacity is 500-3000 J / (kg·K), and its thermal diffusivity is 1.0×10⁻⁶. -5 -1.0×10 -8 m 2 / s, the functional material bed is a cylindrical powder briquette with a diameter of 15cm, a height of 5cm, a porosity of 0.5, and a hydrogen absorption operating pressure of 1-6MPa; In step 2, the screening range for hydrogen storage materials is expanded, with LaNi5 and LaNi5 being the candidate hydrogen storage materials. 4.25 Al 0.75 ZrMn2, Ti 1.05 Y 0.02 Zr 0.03 Fe 0.8 Mn 0.2 Mg 90 Ni 10 Among them, the start-up hydrogen storage material combination that meets the above screening requirements is LaNi5 and LaNi. 4.25 Al 0.75 and ZrMn2, The density of LaNi5 initial hydrogen storage material is 8200 kg / m³. 3 It has a specific heat capacity of 419 J / (kg·K), a hydrogen storage capacity of 1.38 wt.%, a reaction enthalpy of 30.1 kJ / mol H2, and an operating temperature range of room temperature to 110℃. LaNi 4.25 Al 0.75 The starting density of the hydrogen storage material is 7590 kg / m³. 3 It has a specific heat capacity of 419 J / (kg·K), a hydrogen storage capacity of 0.98 wt%, a reaction enthalpy of 41.51 kJ / mol H2, and an operating temperature range of 110℃ to 185℃. The density of ZrMn2 hydrogen storage material is 7100 kg / m³. 3 It has a specific heat capacity of 355 J / (kg·K), a hydrogen storage capacity of 1.57 wt%, a reaction enthalpy of 43.29 kJ / mol H2, and an operating temperature range of 185℃ to 330℃. In step 3, when the functional material bed is a cylindrical Mg hydrogen storage material, the starting hydrogen storage material is LaNi5 or LaNi5. 4.25 Al 0.75 When combined with ZrMn2, First, the hydrogen-induced heating structure is disc-shaped with a diameter of 15cm. The hydrogen-induced heating structure is placed under the functional material bed and is in close contact with the functional material bed. The function of the hydrogen-induced heating structure is to provide heat to the functional material bed only from the top bottom of the disc, and the remaining surfaces of the hydrogen-induced heating structure should minimize heat loss. Then, LaNi5 and LaNi 4.25 Al 0.75 Substituting the physical properties of the three start-up hydrogen storage materials, LaNi5 and LaNi2, into formula (3), we obtain the results. 4.25 Al 0.75 The mass ratio of ZrMn2 to ZrMn2 is 0.17:0.21:0.62, and the adjustment coefficients are α1 = 0.5, α2 = 0.3, and α3 = 1.

0. Finally, based on the thermal diffusivity of the functional material bed, the heating depth of the hydrogen-induced heating structure is determined to be 1-5 mm near the hydrogen-induced heating structure, and the total mass of the hydrogen storage material within the hydrogen-induced heating structure is determined to be 100-300 g, with a total volume of 50-150 cm³. 3 .

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