Integrated heat exchanger and hydrogen liquefaction system

Abstract

The application discloses an integrated heat exchanger and a hydrogen liquefaction system, and relates to the technical field of heat exchangers, and specifically relates to an integrated heat exchanger and a hydrogen liquefaction system. The integrated heat exchanger comprises a core body, an inlet head and an outlet head which are respectively and tightly connected to two ends of the core body, the inlet head comprises a first inlet shell and a second inlet shell which are arranged in a space interval mode, the first inlet shell is used for forming an inlet catalyst packing cavity, an inlet head jacket layer is formed between the first inlet shell and the second inlet shell, a first bypass inlet and a first bypass outlet are arranged on the second inlet shell, cold fluid flows in through the first bypass inlet, flows out through the first bypass outlet after flowing through the inlet head jacket layer, an inlet joint is arranged on a side of the inlet head which is away from the core body, and the inlet joint is connected with the inlet catalyst packing cavity. The application can integrate primary hydrogen and secondary hydrogen catalytic conversion and high-efficiency heat exchange into one body without damaging the micro-channel structure of the printed circuit board type heat exchanger and guaranteeing heat exchange performance.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology for cryogenic refrigeration engineering, and particularly to an integrated heat exchanger and hydrogen liquefaction system. Background Technology

[0002] Hydrogen energy is gaining increasing popularity as a renewable and pollution-free clean energy source. However, the prerequisite for the large-scale use of hydrogen energy is convenient storage and transportation, so the research and large-scale development of hydrogen liquefaction equipment is imperative.

[0003] At room temperature, hydrogen gas consists of approximately 75% ortho-hydrogen and 25% para-hydrogen. As the temperature gradually decreases to the boiling point of liquid hydrogen (approximately 20 K), the equilibrium composition of hydrogen molecules shifts to para-hydrogen comprising over 99%. The conversion from ortho-hydrogen to para-hydrogen is an exothermic reaction. If the ortho-hydrogen content is too high, heat will be continuously released during liquid hydrogen storage, resulting in significant boil-off and impacting storage efficiency and safety. Therefore, hydrogen liquefaction units typically use ortho- and para-hydrogen catalytic converters during the cooling process to gradually complete the ortho- and para-hydrogen conversion, thereby reducing energy consumption and storage losses.

[0004] In the development of hydrogen liquefaction devices, two important pieces of equipment are generally required: catalytic converters and heat exchangers.

[0005] Currently, the commonly used method in the field of hydrogen liquefaction is to combine a catalytic converter with a plate-fin heat exchanger for the catalytic conversion of n- and para-hydrogen. After in-depth research, the inventors of this application have discovered that the aforementioned combination of a catalytic converter and a plate-fin heat exchanger has significant room for optimization and improvement in many aspects.

[0006] For example, independent n- and para-hydrogen catalytic converters have complex structures, which are not conducive to system integration and optimization. For another example, during the n- and para-hydrogen conversion process, the catalyst is affected by the high temperature generated during the n- and para-hydrogen catalytic conversion process, which may cause sintering failure, thereby shortening its service life.

[0007] Therefore, it is necessary to propose an integrated heat exchanger to solve at least one of the above problems.

[0008] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides an integrated heat exchanger and hydrogen liquefaction system. The heat exchanger is a printed circuit board type heat exchanger, which integrates the catalytic conversion of hydrogen and high-efficiency heat exchange without damaging the microchannel structure of the heat exchanger and ensuring heat exchange performance.

[0010] The specific technical solution of the embodiments of the present invention is as follows:

[0011] An integrated heat exchanger includes a core and an inlet head and an outlet head respectively sealed and connected to both ends of the core. The inlet head includes a first inlet shell and a second inlet shell spaced apart internally and externally. The first inlet shell forms an inlet catalyst packing cavity. An inlet head jacket layer is formed between the first inlet shell and the second inlet shell. The second inlet shell has a first bypass inlet and a first bypass outlet. Cold fluid flows in through the first bypass inlet, flows through the inlet head jacket layer, and flows out through the first bypass outlet. The inlet head has an inlet on the side facing away from the core. The inlet connector is connected to the inlet catalyst packing cavity; the outlet end cap includes a first outlet shell and a second outlet shell spaced apart inside and outside. The first outlet shell is used to form the outlet catalyst packing cavity. An outlet end cap jacket layer is formed between the first outlet shell and the second outlet shell. The second inlet shell is provided with a second bypass inlet and a second bypass outlet. Cold fluid flows in through the second bypass inlet, flows through the outlet end cap jacket layer, and flows out through the second bypass outlet. The outlet end cap is provided with an outlet connector on the side away from the core body. The outlet connector is connected to the outlet catalyst packing cavity.

[0012] In a preferred embodiment, the first inlet housing is provided with an inlet catalyst packing port and an inlet catalyst discharge port communicating with the inlet catalyst packing chamber; and / or, the first outlet housing is provided with an outlet catalyst packing port and an outlet catalyst discharge port communicating with the outlet catalyst packing chamber.

[0013] In a preferred embodiment, a first filter assembly is disposed between the inlet end cap and the core; and / or, a second filter assembly is disposed between the outlet end cap and the core; and / or, the first inlet housing and the second inlet housing are respectively provided with inlet mounting holes for installing the inlet connector, the inlet connector is sealed within the inlet mounting holes, and a third filter assembly is disposed in the inlet connector; and / or, the first outlet housing and the second outlet housing are respectively provided with outlet mounting holes for installing the outlet connector, the outlet connector is sealed within the outlet mounting holes, and a fourth filter assembly is disposed in the outlet connector.

[0014] In a preferred embodiment, the first filter assembly, the second filter assembly, the third filter assembly, or the fourth filter assembly comprises, in sequence, a first pressure-bearing support layer, a fine filter layer, and a second pressure-bearing support layer, wherein the pore size of the fine filter layer is smaller than the minimum particle size of the catalyst.

[0015] In a preferred embodiment, an inlet flow equalization orifice plate is arranged in the inlet catalyst packing cavity along the fluid flow direction; and / or, an outlet flow equalization orifice plate is arranged in the outlet catalyst packing cavity along the fluid flow direction; when there are multiple inlet flow equalization orifice plates, the multiple inlet flow equalization orifice plates are arranged at intervals along the fluid flow direction; and / or, when there are multiple outlet flow equalization orifice plates, the multiple outlet flow equalization orifice plates are arranged at intervals along the fluid flow direction.

[0016] In a preferred embodiment, the catalyst bed formed in the inlet catalyst packing chamber and the catalyst bed formed in the outlet catalyst packing chamber differ in at least one of the following: catalyst type, packing height, bed porosity, and catalyst particle size.

[0017] In a preferred embodiment, the catalyst in the inlet catalyst packing chamber is different from the catalyst in the outlet catalyst packing chamber. The catalyst in the inlet catalyst packing chamber includes an iron-based catalyst or a noble metal supported catalyst; the catalyst in the outlet catalyst packing chamber includes a rare earth oxide catalyst or a composite catalyst.

[0018] In a preferred embodiment, the core is provided with a cold-side inlet for the inflow of cold fluid into the core and a cold-side outlet for the outflow of cold fluid through the core. The integrated heat exchanger further includes: a first cooling bypass, one end of which is connected to the cold-side inlet and the other end of which is connected to the first bypass inlet, and a first bypass regulating valve is provided on the first cooling bypass; and / or, the integrated heat exchanger further includes: a second cooling bypass, one end of which is connected to the cold-side inlet and the other end of which is connected to the second bypass inlet, and a second bypass regulating valve is provided on the second cooling bypass.

[0019] In a preferred embodiment, the catalyst loading amount m in the inlet catalyst packing chamber or the catalyst loading amount m in the outlet catalyst packing chamber cat The following relationship must be satisfied:

[0020]

[0021] Among them, Q g This is the hydrogen inlet volumetric flow rate, in m³ / s. 3 / s,k vThe effective volume reaction rate constant is expressed in seconds. -1 X is the target conversion rate, ρ b The catalyst bulk density is expressed in kg / m³. 3 .

[0022] A hydrogen liquefaction system, the hydrogen liquefaction system including any of the integrated heat exchangers described above, the hydrogen liquefaction system further including a controller, a hydrogen inlet regulating valve disposed on or upstream of the inlet connector, and a hydrogen outlet regulating valve disposed on or downstream of the outlet connector, the hydrogen inlet regulating valve and the hydrogen outlet regulating valve being electrically connected to the controller.

[0023] In a preferred embodiment, the controller stores a method for verifying the heat transfer area of ​​the inlet and outlet end caps. The verification method includes: determining a target heat transfer area based on the reaction heat power, the logarithmic mean temperature difference between the hot and cold ends, and the overall heat transfer coefficient, such that the actual heat transfer area is greater than or equal to the target heat transfer area. The technical solution of this invention has the following significant beneficial effects:

[0024] In this embodiment, a printed circuit board-type heat exchanger core is innovatively used as the heat exchange hub, with inlet and outlet end caps sealed at both ends. The end caps adopt an inner and outer shell design, where the inner shell forms the catalyst packing cavity, and the outer shell forms a jacket layer between the inner and outer layers. Cold fluid flows through the jacket layer to rapidly remove the reaction heat from the catalyst packing cavity, thus integrating catalytic conversion and heat exchange functions into one. Through the above improvements, the system integration is greatly enhanced: specifically, the independent reactor is eliminated, reducing the footprint, reducing pipeline connections, reducing cold loss, and reducing equipment investment; long-term stable operation of the catalytic reaction is achieved: the cold fluid in the jacket layer directly cools the catalyst bed and removes the catalytic reaction heat, controlling the catalytic conversion process of n- and para-hydrogen in a near-isothermal or temperature-controlled state, avoiding catalyst sintering and failure at high temperatures, effectively extending catalyst life, and ensuring high catalytic conversion efficiency. Improved liquefaction rate: Compared to plate-fin heat exchangers, printed circuit board heat exchangers have a higher heat transfer coefficient and a smaller heat transfer temperature difference, which allows the cold end temperature to be closer to the refrigerant temperature, and can achieve a higher liquefaction rate under the same operating conditions.

[0025] Specific embodiments of the invention are disclosed in detail below with reference to the description and accompanying drawings, indicating how the principles of the invention can be employed. It should be understood that the embodiments of the invention are not therefore limited in scope. Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. Attached Figure Description

[0026] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0027] Figure 1 This is a schematic diagram of the structure of an integrated heat exchanger provided in the embodiments of this application;

[0028] Figure 2 This is a schematic diagram of the inlet end cap of an integrated heat exchanger provided in the embodiments of this application;

[0029] Figure 3 for Figure 2 A left view of the inlet head of an integrated heat exchanger provided in the embodiments of this application;

[0030] Figure 4 A schematic diagram of the internal fluid flow in an inlet head without an internal flow equalization orifice plate;

[0031] Figure 5 This is a schematic diagram of the internal fluid flow in the inlet head of an integrated heat exchanger provided in the embodiments of this application;

[0032] Figure 6 This is a schematic diagram showing the inlet and outlet end caps of an integrated heat exchanger provided in this application after being filled with catalyst;

[0033] Figure 7 This is a schematic diagram of an integrated heat exchanger provided in this application, with the inlet end cap filled with a catalyst;

[0034] Figure 8 for Figure 7 A right view of the inlet head of an integrated heat exchanger provided in the embodiments of this application;

[0035] Figure 9 This is a schematic diagram of the structure of a hydrogen liquefaction system provided in the embodiments of this application.

[0036] The reference numerals in the above figures are as follows:

[0037] 1. Core;

[0038] 2. Entrance cap;

[0039] 21. First inlet shell;

[0040] 22. Second inlet shell;

[0041] 23. Inlet catalyst packing chamber;

[0042] 24. Entrance head jacket layer;

[0043] 25. First bypass entrance;

[0044] 26. First bypass exit;

[0045] 27. Inlet connector;

[0046] 28. Inlet catalyst packing port;

[0047] 29. Catalyst inlet discharge port;

[0048] 3. Export cap;

[0049] 31. First outlet shell;

[0050] 32. Second outlet shell;

[0051] 33. Outlet catalyst packing chamber;

[0052] 34. Exit head jacket layer;

[0053] 35. Second bypass entrance;

[0054] 36. Second bypass exit;

[0055] 37. Outlet connector;

[0056] 38. Catalyst outlet packing port;

[0057] 39. Catalyst discharge port at the outlet;

[0058] 4. First filter component;

[0059] 5. Second filter component;

[0060] 6. Third filter component;

[0061] 7. Fourth filter component;

[0062] 41. First pressure-bearing support layer;

[0063] 42. Fine filtration layer;

[0064] 43. Second pressure-bearing support layer;

[0065] 8. Inlet flow equalization orifice plate;

[0066] 9. Outlet flow equalization orifice plate;

[0067] 10. Cold side inlet;

[0068] 11. Cold side outlet;

[0069] 12. First cooling bypass;

[0070] 13. First bypass regulating valve;

[0071] 14. Second cooling bypass;

[0072] 15. Second bypass regulating valve;

[0073] 17. Hydrogen inlet regulating valve;

[0074] 18. Hydrogen outlet regulating valve. Detailed Implementation

[0075] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "connected" should be interpreted broadly, for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0077] In existing hydrogen liquefaction systems, the catalytic conversion and heat exchange of ortho- and para-hydrogen are typically achieved using the following two methods:

[0078] One approach involves connecting an independent catalytic reactor with a conventional heat exchanger (plate-fin heat exchanger) in series. This approach has the following drawbacks:

[0079] Low system integration: Independent equipment increases the floor space and connecting pipelines, resulting in a complex internal structure of the cold box, increased cold loss, and a significant increase in equipment investment and operating costs.

[0080] Secondly, the catalyst is filled inside the plate-fin heat exchanger. This method has the following drawbacks:

[0081] Poor heat removal efficiency during internal filling of the head: The heat generated by the exothermic reaction of catalytic conversion cannot be removed in time, which will lead to high-temperature sintering and deactivation of the catalyst. Due to local agglomeration and uneven fluid distribution, "dead zones" and "short-circuit channels" appear in the catalyst bed, causing a sharp drop in catalytic efficiency.

[0082] When filling the heat exchange channel, it is difficult to pack the catalyst evenly, and the channel resistance increases significantly. The catalyst cannot be replaced online, and there is a high risk of blockage. At the same time, when hydrogen enters the heat exchanger from the reactor, jets and backflows are easily formed in the head, resulting in a large deviation in the flow distribution in the heat exchanger and a decrease in heat exchange efficiency.

[0083] Catalyst maintenance is inconvenient: loading and unloading require dismantling equipment or pipelines, which damages the cold box's insulation structure, resulting in long maintenance times and significant cold loss and downtime losses.

[0084] Poor adaptability to operating conditions: There are differences in operating conditions between the inlet (high temperature, high positive hydrogen content) and the outlet (low temperature, low positive hydrogen content). When using a single catalyst bed design, the optimal catalytic conversion efficiency cannot be obtained.

[0085] This invention provides an integrated heat exchanger and hydrogen liquefaction system that integrates the catalytic conversion of hydrogen and high-efficiency heat exchange into one unit without damaging the microchannel structure of the printed circuit board heat exchanger and ensuring heat exchange performance.

[0086] Please refer to the following for comprehensive information. Figures 1 to 8This application specification provides an integrated heat exchanger, which may include: a core 1 and an inlet end cap 2 and an outlet end cap 3 respectively sealed and connected to both ends of the core 1. The inlet end cap 2 includes a first inlet shell 21 and a second inlet shell 22 spaced apart. The first inlet shell 21 forms an inlet catalyst packing cavity 23. An inlet end cap jacket layer 24 is formed between the first inlet shell 21 and the second inlet shell 22. The second inlet shell 22 is provided with a first bypass inlet 25 and a first bypass outlet 26. Cold fluid flows in through the first bypass inlet 25, flows through the inlet end cap jacket layer 24, and flows out through the first bypass outlet 26. The inlet end cap 2 has a side facing away from the core 1. An inlet connector 27 is provided, which is connected to the inlet catalyst packing cavity 23; the outlet end cap 3 includes a first outlet shell 31 and a second outlet shell 32 spaced apart inside and outside. The first outlet shell 31 is used to form the outlet catalyst packing cavity 33. An outlet end cap jacket layer 34 is formed between the first outlet shell 31 and the second outlet shell 32. The second inlet shell 22 is provided with a second bypass inlet 35 and a second bypass outlet 36. Cold fluid flows in through the second bypass inlet 35, flows through the outlet end cap jacket layer 34 and flows out through the second bypass outlet 36. An outlet connector 37 is provided on the side of the outlet end cap 3 away from the core 1, and the outlet connector 37 is connected to the outlet catalyst packing cavity 33.

[0087] Given the shortcomings of current plate-fin heat exchangers discovered by the inventors, after in-depth research and comparison, they found that printed circuit board heat exchangers have stronger pressure resistance and thermal shock resistance compared to plate-fin heat exchangers, and also have a higher heat transfer coefficient, resulting in a more compact structure and higher liquefaction efficiency.

[0088] In this embodiment of the application, the core 1 of the integrated heat exchanger can be the core 1 of a printed circuit board heat exchanger.

[0089] Printed Circuit Heat Exchangers (PCHEs) are a type of indirect-contact microchannel heat exchanger. Their structural characteristics ensure that they have advantages such as high pressure resistance, high heat transfer coefficient, and wide applicable temperature range, making them the most compact type of heat exchanger currently available.

[0090] The intermediate hydrogen catalysts include iron-based catalysts, rare earth oxide catalysts, and noble metal supported catalysts, with particle sizes typically ranging from 0.5 to 3 mm.

[0091] Existing plate-fin heat exchangers have relatively large channel dimensions (2-5mm), which can be achieved by... Inside the heat exchange channelAdding catalysts enables a continuous catalytic conversion process.

[0092] However, if a plate-fin heat exchanger is directly replaced with a printed circuit board heat exchanger, the catalyst cannot be uniformly packed in the microchannels inside the printed circuit board heat exchanger, which will lead to a significant increase in microchannel resistance. Furthermore, the catalyst cannot be replaced online, and the risk of blockage cannot be eliminated in time. Moreover, if the heat generated by the exothermic reaction of catalytic conversion cannot be carried away in time when the catalyst is packed in the head, it will cause the catalyst to sinter at high temperature and become deactivated. Due to local agglomeration and uneven fluid distribution, "dead zones" and "short-circuit channels" appear in the catalyst bed, causing a sharp drop in catalytic efficiency.

[0093] As can be seen from the above, given that the channel size of PCHE heat exchangers is typically 0.5-2 mm, or even smaller, directly filling the microchannels with catalyst particles can easily lead to problems such as blockage, a sharp increase in pressure drop, and a decrease in heat exchange performance. Therefore, the channel filling method is not suitable for PCHE heat exchangers.

[0094] Therefore, independent normal-to-parahydrogen catalytic converters are still widely used in industry, with catalysts packed inside and connected in series between heat exchanger systems. Compared with continuous catalytic conversion, independent normal-to-parahydrogen catalytic converters have disadvantages such as complex system structure and are not conducive to the structural integration of miniaturized hydrogen liquefaction devices.

[0095] As can be seen from the above, there are currently technical difficulties in replacing plate-fin heat exchangers with printed circuit board heat exchangers and forming integrated heat exchangers with catalytic conversion functions.

[0096] In this embodiment, a printed circuit board heat exchanger core 1 is innovatively used as the heat exchange core, with inlet end cap 2 and outlet end cap 3 sealed at both ends. The end cap adopts an inner and outer shell design, where the inner shell forms a catalyst packing cavity, and the outer shell and inner shell form a jacket layer of the end cap. Cold fluid flows through the jacket layer to achieve rapid removal of reaction heat, thereby integrating catalytic conversion and heat exchange functions into one. Through the above improvements, the system integration is greatly improved: specifically, the independent reactor is eliminated, reducing the footprint, reducing pipeline connections, reducing cold loss, and reducing equipment investment; the cold fluid in the jacket layer carries away the catalytic reaction heat by cooling the catalyst bed, avoiding catalyst sintering and failure at high temperatures, and ensuring catalytic conversion efficiency under long-term operation; compared with plate-fin heat exchangers, printed circuit board heat exchangers have a higher heat transfer coefficient and a smaller minimum temperature difference, which can make the cold end temperature closer to the refrigerant temperature, and achieve a higher liquefaction rate under the same operating conditions.

[0097] The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0098] Please refer to the following: Figure 1 ,Figure 2 and Figure 3 In this embodiment, the integrated heat exchanger mainly includes: a core 1 and an inlet end cap 2 and an outlet end cap 3 respectively sealed and connected to both ends of the core 1. The inlet end cap 2 and the outlet end cap 3 are similar in composition, shape, and structure. In this embodiment, the inlet end cap 2 is used as an example, and the outlet end cap 3 can be described with reference to the inlet end cap 2. Further details will not be provided here.

[0099] The inlet cap 2 includes a first inlet shell 21 and a second inlet shell 22 spaced apart from each other. The first inlet shell 21 is used to form an inlet catalyst packing cavity 23. An inlet connector 27 is provided on the side of the inlet cap 2 away from the core 1, and the inlet connector 27 is connected to the inlet catalyst packing cavity 23.

[0100] Please refer to the following: Figure 6 , Figure 7 and Figure 8 When the integrated heat exchanger is used in the field of hydrogen liquefaction, the inlet catalyst packing chamber 23 is filled with ortho- and para-hydrogen catalytic conversion catalyst particles to form a catalyst bed.

[0101] An inlet end cap jacket layer 24 (hereinafter referred to as the jacket) is formed between the first inlet shell 21 and the second inlet shell 22. The second inlet shell 22 is provided with a first bypass inlet 25 and a first bypass outlet 26. In use, hydrogen flows into the first inlet shell 21 of the inlet end cap 2 through the inlet connector 27, and comes into contact with the catalyst to carry out a catalytic reaction. Cold fluid flows in through the first bypass inlet 25, flows through the inlet end cap jacket layer 24 and flows out through the first bypass outlet 26. The cold fluid carries away the reaction heat generated by the conversion of ortho- and para-hydrogen in the catalyst bed, thereby controlling the catalyst bed temperature and inhibiting catalyst sintering deactivation, ensuring the service life of the catalyst; ensuring the stable operation of the downstream microchannel heat exchanger, ensuring efficient heat exchange while controlling the ortho- and para-hydrogen catalytic conversion process in a state of near isothermal or controllable temperature rise.

[0102] In this embodiment, the volume of the first inlet shell 21 can be adaptively designed according to the different amounts of catalyst loaded.

[0103] Specifically, the catalyst loading amount m in the inlet catalyst packing chamber 23 cat The following relationship must be satisfied:

[0104]

[0105] Among them, Q g This is the hydrogen inlet volumetric flow rate, in m³ / s. 3 / s,k vThe effective volume reaction rate constant is expressed in seconds. -1 X is the target conversion rate, ρ b The catalyst bulk density is expressed in kg / m³. 3 .

[0106] The amount of catalyst loaded in the outlet catalyst packing chamber 33 also satisfies the above relationship.

[0107] Traditional catalyst loading methods rely on scale-up or overloading designs, often resulting in more catalyst than actually needed. This leads to increased pressure drop in the catalyst bed and higher catalyst costs. In this application, the catalyst loading amount is precisely calculated using the aforementioned formula, allowing for accurate matching of the required amount and on-demand allocation. This reduces the amount of catalyst loaded, lowers catalyst costs, reduces pressure drop in the catalyst bed, and achieves a balance between catalytic efficiency and pressure drop.

[0108] In actual operation, hydrogen gas from... Figure 7 The inlet connector 27 shown enters the inlet head 2, undergoes ortho-parahydrogen conversion in the catalyst bed and releases reaction heat. This heat is transferred to the inlet head jacket layer 24 through the first inlet shell 21, and then carried away by the cold fluid flowing in the inlet head jacket layer 24 by convection heat transfer. This controls the catalyst bed temperature, suppresses local overheating and catalyst sintering, effectively extends the service life of the catalyst and reduces the frequency of catalyst replacement.

[0109] In one embodiment, the core 1 is provided with a cold-side inlet 10 for allowing cold fluid to flow into the core 1 and a cold-side outlet 11 for discharging the cold fluid flowing through the core 1. The integrated heat exchanger further includes: a first cooling bypass 12, one end of which is connected to the cold-side inlet 10 and the other end of which is connected to the first bypass inlet 25, and a first bypass regulating valve 13 is provided on the first cooling bypass 12; and / or, the integrated heat exchanger further includes: a second cooling bypass 14, one end of which is connected to the cold-side inlet 10 and the other end of which is connected to the second bypass inlet 35, and a second bypass regulating valve 15 is provided on the second cooling bypass 14.

[0110] In this embodiment, the cooling bypass directly draws cooling from the cold side inlet 10 of the core 1, eliminating the need for additional cooling by a refrigeration unit as in traditional reactors. This achieves efficient cascade utilization of cooling capacity, significantly improving cooling capacity utilization efficiency. It also avoids additional cooling power consumption, significantly reducing the total energy consumption of the system and lowering operating costs.

[0111] The bypass regulating valve features high adjustment accuracy and fast response speed. For example, a temperature sensor can be installed inside the inlet head 2 to detect the temperature of the catalyst bed. This bypass regulating valve and temperature sensor can be electrically connected to the controller, forming a closed-loop control system. It can quickly respond to changes in bed temperature and stabilize the bed temperature within the optimal activity range of the catalyst by adjusting the flow rate of the cold fluid, avoiding catalyst activity decay caused by temperature fluctuations and maintaining the catalyst in a high-activity state.

[0112] To address the significant difference in exothermic load between the inlet head 2 and the outlet head 3, the dual bypass design employs different flow rate adjustment ranges to achieve on-demand distribution of cooling capacity. This avoids the problems of wasted or insufficient cooling capacity in traditional single bypass systems, ensuring that the outlet bed temperature remains stable within the optimal activity range of the catalyst and improving the fine conversion efficiency.

[0113] By flexibly adjusting the bypass flow rate, the system can maintain a stable bed temperature within a wide range of hydrogen flow fluctuations, ensuring that the conversion rate of ortho- and para-hydrogen remains at a high level; compared with traditional systems, the range of operating conditions adaptable is greatly expanded.

[0114] Among them, the mass flow rate of the internal cooling fluid in the inlet head jacket layer 24 is m c The derivation and calculation can be performed as follows:

[0115]

[0116] in: The heat power of the reaction is expressed in W. This is the mass flow rate of hydrogen, in kg / s; , These are the positive hydrogen mass fractions at the catalyst bed inlet and outlet, respectively. The heat of reaction for the positive hydrogen conversion is expressed in J / kg. According to the law of conservation of energy:

[0117]

[0118] in: The specific heat capacity at constant pressure for a cold fluid, J / (kg·K). and These are the outlet and inlet temperatures of the cold fluid, respectively, in K.

[0119] Introducing heat transfer efficiency coefficient We can obtain:

[0120]

[0121] During engineering design, the target conversion rate can be determined. Then, the cold fluid flow rate is obtained from the above formula. The magnitude of this cold fluid flow rate is determined by... Figure 9The control valve (e.g., first bypass control valve 13) on the cold fluid cooling bypass shown is used to achieve this.

[0122] Simultaneously, the inner surface area of ​​the inlet end cap jacket layer 24 can be calculated to determine whether the current inner surface area of ​​the jacket meets the cooling requirements for the heat of reaction of the normal and secondary hydrogens. That is, the exothermic reaction of the normal-secondary hydrogen catalytic conversion is known. Based on the operating conditions of the cold fluid inside the jacket of inlet head 2 and the geometric dimensions of inlet head 2, the required heat exchange area is calculated. ,req and the actual inner surface area of ​​the current jacket. ,geo In contrast, if:

[0123]

[0124] This indicates that the jacket design meets the heat dissipation requirements; otherwise, the size of the inlet head 2 needs to be increased and the jacket structure optimized. The specific verification method is as follows:

[0125] Calculate the logarithmic mean temperature difference between the hot and cold ends.

[0126] The inner wall temperature of the inlet head 2 can be approximated as close to the gas-solid mixing temperature of the catalyst bed, while the temperature of the cooling fluid inside the inlet head jacket layer 24 increases along the flow path. The LMTD formula is used:

[0127] =

[0128] =

[0129]

[0130] Determine the heat transfer coefficient on the reaction side (catalyst bed side). .

[0131] This invention uses the Wakao-Kaguei correlation to estimate the gas-solid heat transfer coefficient within the catalyst bed. The specific formula is as follows:

[0132]

[0133]

[0134]

[0135]

[0136] in: Where is the particle size of the catalyst, in meters (m). The density of the gas is kg / m³. 3 ; The empty tower velocity is in m / s; is the thermal conductivity of the gas, W / (m·K); ρ is the specific heat of the gas, J / (kg·K); ρ is the viscosity of the gas, kg / (m·s).

[0137] When the fluid conditions are not suitable for the Wakao-Kaguei correlation, other correlation types can also be used.

[0138] Determine the heat transfer coefficient on the cold fluid side .

[0139] The inlet head jacket layer 24 is considered as an annular flow channel between the outer wall and inner wall of the inlet head 2. The cold fluid undergoes convective heat transfer along this channel with the inner surface of the inlet jacket. Taking a semi-circular head cross-section as an example, the flow cross-sectional area... It can be approximated as follows:

[0140]

[0141] in: and Here, H and H represent the cross-sectional radii of the inner and outer walls of the inlet head jacket layer 24, respectively. When the annular gap width H is less than 0.1 times the cross-sectional radius, the wetted perimeter can be approximated as follows:

[0142]

[0143] Therefore, the hydraulic diameter of the annular gap channel can be obtained:

[0144]

[0145] For irregular inlet head 2 sections, the hydraulic diameter of the annular flow channel can be calculated by taking the equivalent diameters of the inlet head 2 inside and outside the section. From this, the average velocity of the cold fluid can be obtained:

[0146]

[0147] in, The density of the cold fluid is kg / m³. 3 Therefore, the cold fluid can be obtained. and :

[0148]

[0149]

[0150] in, The viscosity of the cold fluid is expressed in kg / (m·s). is the thermal conductivity of the cold fluid, W / (m·K); The specific heat of the cold fluid is expressed in J / (kg·K). This invention preferentially uses the Dittus-Boelter correlation to estimate the convective heat transfer coefficient within the annular channel:

[0151]

[0152]

[0153] Dittus-Boelter correlations are applicable to For turbulent flow with a value >10000, other correlation types can be used when the fluid conditions are not suitable.

[0154] Therefore, the overall heat transfer coefficient can be obtained. U :

[0155]

[0156] in, The thickness of the inner wall of the jacket is in meters (m). The thermal conductivity of the inner wall of the inlet end cap jacket layer 24 (hereinafter referred to as the jacket) is W / (m·K); For the thermal resistance of dirt, m 2 ·K / W. This can be calculated using U:

[0157]

[0158] The actual usable inner surface area of ​​the inlet head jacket layer 24 for heat exchange is calculated based on the geometric dimensions of the inlet head 2. For irregular entrance caps 2, the area can be calculated using the integration method. Then, a verification process is performed. If:

[0159]

[0160] This indicates that the current inlet head 2 size can meet the heat dissipation requirements of the exothermic catalytic reaction, and the jacket design is reasonable; if:

[0161]

[0162] The inlet head 2 size can be appropriately increased to increase the actual heat exchange area. Alternatively, the jacket structure of the inlet end cap 2 can be optimized to improve the heat transfer coefficient on the cold fluid side. This reduces the required heat exchange area. .

[0163] In this embodiment of the application, by establishing a quantitative relationship between catalyst loading and hydrogen flow rate, target conversion rate, end cap (e.g., inlet end cap 2), a clear basis can be provided for the design of systems of different scales, ensuring that the integrated heat exchanger has high adaptability to operating conditions and can better meet the urgent needs of hydrogen liquefaction technology development.

[0164] In one embodiment, the first inlet housing 21 is provided with an inlet catalyst packing port 28 and an inlet catalyst discharge port 29 that communicate with the inlet catalyst packing chamber 23; and / or, the first outlet housing 31 is provided with an outlet catalyst packing port 38 and an outlet catalyst discharge port 39 that communicate with the outlet catalyst packing chamber 33.

[0165] In this embodiment, the first inlet housing 21 is provided with an inlet catalyst packing port 28 and an inlet catalyst discharge port 29 that communicate with the inlet catalyst packing cavity 23, as an example.

[0166] The inlet catalyst packing port 28 can specifically be a short pipe structure with a valve and a sealing gasket. The inlet catalyst packing port 28 is located at the upper part of the inlet head 2, and the inlet catalyst discharge port 29 is located at the lower part of the inlet head 2. Thus, when packing is needed, the inlet catalyst discharge port 29 can be closed. The inlet catalyst packing port 28 can be connected to the catalyst storage tank via a flexible pipe, allowing for gravity-fed filling, or the catalyst can be loaded from top to bottom into the inlet catalyst packing chamber 23 by gravity and necessary purging gas. When unloading is needed, the inlet catalyst discharge port 29 can be opened, allowing the catalyst to be discharged from bottom to top, achieving automatic unloading under gravity, or unloading with the assistance of purging gas or vibration, thereby increasing the unloading speed. Of course, in this embodiment, unloading from bottom to top by means of purging gas or other methods is also possible.

[0167] In addition, when it is necessary to clean the PCHE microchannels, the packing port / discharge port can be used as a guide port to introduce the cleaning medium or inert gas to achieve online cleaning.

[0168] By rationally arranging the filling and unloading ports, and combining gravity loading with gas purging to assist unloading, the catalyst loading and unloading speed is greatly improved; the amount of catalyst residue in the bed can be effectively reduced, avoiding the mixing and contamination problems of traditional equipment, and significantly shortening the time for a single maintenance operation.

[0169] The maintenance process does not require dismantling equipment connections or damaging the cold box insulation layer; it can be operated simply by closing the inlet and outlet valves, which greatly reduces temperature fluctuations inside the cold box and significantly reduces cold loss. The total maintenance time is greatly shortened, effectively reducing economic losses caused by downtime and lowering annual maintenance costs.

[0170] By utilizing the packing port and discharge port, a purging-collection loop can be constructed to achieve online cleaning of PCHE microchannels and catalyst beds; when heat exchange efficiency decreases due to impurities clogging, equipment performance can be quickly restored, avoiding long-term downtime caused by traditional offline disassembly and cleaning, and increasing the effective operating time of the equipment.

[0171] The top-and-bottom distributed interface design enables the catalyst to form a stable flow state. Combined with the flow guiding effect of the flow equalization plate, it can significantly reduce the deviation of the bed packing density. The improved packing uniformity can optimize the fluid velocity distribution in the bed, reduce catalyst wear, and avoid the problem of incomplete local conversion.

[0172] In one embodiment, a first filter assembly 4 is disposed between the inlet end cap 2 and the core 1; and / or, a second filter assembly 5 is disposed between the outlet end cap 3 and the core 1; and / or, the first inlet housing 21 and the second inlet housing 22 are respectively provided with inlet mounting holes for installing the inlet connector 27, the inlet connector 27 is sealed within the inlet mounting holes, and a third filter assembly 6 is disposed in the inlet connector 27; and / or, the first outlet housing 31 and the second outlet housing 32 are respectively provided with outlet mounting holes for installing the outlet connector 37, the outlet connector 37 is sealed within the outlet mounting holes, and a fourth filter assembly 7 is disposed in the outlet connector 37.

[0173] Specifically, the first filter assembly 4, the second filter assembly 5, the third filter assembly 6, or the fourth filter assembly 7 include, in sequence, a first pressure-bearing support layer 41, a fine filter layer 42, and a second pressure-bearing support layer 43, wherein the pore size of the fine filter layer 42 is smaller than the minimum particle size of the catalyst.

[0174] Among them, such as Figure 2 and Figure 3 As shown, the fine filter layer 42 can be made of stainless steel or nickel-based alloy fine metal wire mesh, the mesh size of which is determined according to the catalyst particle size and the PCHE microchannel size, so that the sieve hole size is smaller than the minimum particle size of the catalyst; the first pressure-bearing support layer 41 and the second pressure-bearing support layer 43 can be made of sintered metal mesh or perforated support plate, used to bear the weight of the bed and pressure difference, and prevent the fine filter layer 42 from bulging and deforming. This three-layer filter assembly supports the catalyst bed on the one hand, preventing particles from migrating or sliding with the fluid; on the other hand, it effectively prevents catalyst particles and fine powder from entering the joints (inlet joint 27 / outlet joint 37) and microchannels, avoiding blockage that causes a sudden increase in pressure drop and deterioration of heat transfer.

[0175] In one embodiment, an inlet flow equalization orifice plate 8 is arranged in the inlet catalyst packing cavity 23 along the fluid flow direction; and / or, an outlet flow equalization orifice plate 9 is arranged in the outlet catalyst packing cavity 33 along the fluid flow direction; when there are multiple inlet flow equalization orifice plates 8, the multiple inlet flow equalization orifice plates 8 are arranged at intervals along the fluid flow direction; and / or, when there are multiple outlet flow equalization orifice plates 9, the multiple outlet flow equalization orifice plates 9 are arranged at intervals along the fluid flow direction.

[0176] In this embodiment, taking the inlet head 2 as an example, multiple inlet flow equalization plates 8 are arranged at intervals along the mainstream direction of hydrogen. The multiple inlet flow equalization plates 8 cooperate with the inlet connector 27, the third filter assembly 6, and the first filter assembly 4 to divide the large cross-section channel in the inlet head 2 into multiple restricted small channels.

[0177] Please compare and refer to the following: Figure 4 and Figure 5 ,like Figure 4 As shown, when there is no flow equalization orifice plate in the inlet head 2, hydrogen gas enters from the inlet connector 27 and forms obvious jet and local backflow in the inlet head 2. A large amount of fluid flows around to the inner wall of the inlet head 2 and then backflows, resulting in a severe non-uniform velocity field. High velocity zones and dead zones appear at the inlet and outlet of some microchannels.

[0178] like Figure 5 As shown, when multiple flow equalization plates are installed inside the end cap, the incoming flow is divided into several micro-jet streams at each layer of the flow equalization plates, and then re-merges and mixes within the spacing between the flow equalization plates. The superposition of multiple flow equalization plates weakens large-scale jets and backflow, resulting in a nearly uniform velocity distribution of the fluid on the cross-section near the first filter assembly. This improves the uniformity of flow distribution when entering the PCHE microchannel and the catalytic conversion efficiency of the catalyst bed. Simultaneously, the catalyst particles accumulate to form a porous bed, whose pore structure can be considered a uniform porous medium. The bed itself also has a rectifying and flow equalization effect; the same applies on the outlet side. The combined effect of the multiple flow equalization plates and the catalyst bed significantly weakens jets and backflow within the end cap, reduces dead zone volume, and improves the stability of heat transfer and catalytic conversion processes.

[0179] In one embodiment, the catalyst bed formed in the inlet catalyst packing chamber 23 and the catalyst bed formed in the outlet catalyst packing chamber 33 differ in at least one of the following: catalyst type, packing height, bed porosity, and catalyst particle size.

[0180] Specifically, the catalyst in the inlet catalyst packing chamber 23 is different from the catalyst in the outlet catalyst packing chamber 33. The catalyst in the inlet catalyst packing chamber 23 includes an iron-based catalyst or a noble metal supported catalyst; the catalyst in the outlet catalyst packing chamber 33 includes a rare earth oxide catalyst or a composite catalyst.

[0181] Differentiated design of inlet and outlet catalyst beds. Due to the differences in operating conditions between the inlet and outlet sides, this invention preferably employs a differentiated design for the catalyst beds in the inlet catalyst packing cavity 23 and the outlet catalyst packing cavity 33 to achieve more ideal technical results:

[0182] Inlet bed. The hydrogen temperature is relatively high, and the positive hydrogen content is far from the equilibrium composition, mainly undertaking the "crude conversion" task with large exothermic properties; the bed height and packing volume are large to ensure sufficient conversion rate; the catalyst type can be iron-based or noble metal supported catalyst with high activity and good heat resistance; the particle size is moderate to balance pressure drop and mass transfer performance.

[0183] The outlet bed. After being cooled by core 1, the temperature of the hydrogen gas is significantly reduced or has approached the liquid hydrogen temperature range, and the positive hydrogen content is close to the equilibrium value. It mainly undertakes the tasks of "fine conversion" and maintaining storage stability. To reduce the additional pressure drop, the bed height and packing amount can be appropriately reduced. The catalyst type can be a rare earth oxide catalyst with better low-temperature activity or a composite catalyst with a different combination with the inlet bed. The particle size can be appropriately reduced or the bed porosity can be adjusted to improve the effective activity and mass transfer rate under low-temperature conditions.

[0184] Through the above-mentioned differentiated configuration, the inlet bed is concentrated to process most of the positive hydrogen and absorbs the main heat of reaction with the help of jacket cooling; the outlet bed focuses on low-temperature fine conversion and flow field regulation. The synergy of the two can achieve the optimal balance between overall conversion rate, pressure drop and temperature control.

[0185] In a preferred embodiment, the catalyst loading amount m in the inlet catalyst packing chamber 23 or the catalyst loading amount m in the outlet catalyst packing chamber 33 cat The following relationship must be satisfied:

[0186]

[0187] Among them, Q g This is the hydrogen inlet volumetric flow rate, in m³ / s. 3 / s,k v The effective volume reaction rate constant is expressed in seconds. -1 X is the target conversion rate, ρ b The catalyst bulk density is expressed in kg / m³. 3 .

[0188] In this application, a relationship between catalyst loading and operating parameters is provided. To guide engineering design, this invention preferably establishes an explicit relationship between catalyst loading and hydrogen flow rate, target conversion rate, and catalyst performance. The catalyst bed is considered as an ideal plug flow reactor with first-order apparent kinetics, and the loading... mcat The derivation is as follows:

[0189]

[0190]

[0191] in, The target conversion rate. For example, if the inlet positive hydrogen concentration is 75% and the outlet target is 25%, then the conversion rate is... =0.667; The effective volume reaction rate constant is expressed in seconds. -1 This constant integrates the intrinsic activity of the catalyst, internal diffusion and external mass transfer resistance, as well as heat transfer effects, and is an apparent kinetic constant; When empty, the unit is seconds (s), defined as the reactor volume. (m) 3 ) and inlet volumetric flow rate (m) 3 The ratio of ( / s) reflects the average residence time of the material in the reactor.

[0192] Combining the above equations, we get:

[0193]

[0194]

[0195] in, The catalyst bulk density is expressed in kg / m³. 3 Combining the above equations, we get:

[0196]

[0197] During actual filling, different inlet and outlet bed layers were selected respectively. and This establishes a correlation between operating conditions, catalyst performance, and loading amount, facilitating scale-up design and parameter optimization.

[0198] This quantitative formula achieves accurate calculation of catalyst loading by coupling reaction kinetics, material balance, and physical properties, replacing the traditional empirical method that relies on similar scale-up or over-design; it avoids the problem of increased bed pressure drop caused by over-design, improves design reliability and rationality, and optimizes system performance.

[0199] The formula reveals the linear relationship between the loading amount and the hydrogen flow rate, as well as the logarithmic relationship with the target conversion rate, providing a clear scale-up basis for the design of systems of different scales; it eliminates the need for re-testing and verification for each scale, significantly shortens the design cycle, improves design efficiency, and avoids design deviations caused by scaling down.

[0200] The formula allows for precise calculation of the inlet and outlet bed loading amounts, enabling on-demand catalyst allocation. This avoids catalyst waste caused by traditional single-bed designs, reduces the total catalyst loading amount, and, combined with differentiated catalyst selection, significantly lowers catalyst procurement costs.

[0201] The reaction rate constant in the formula serves as the core indicator of catalyst activity, providing quantitative support for catalyst selection. By comparing the reaction rate constants of different catalysts and combining the results of the loading amount calculation, a suitable catalyst can be flexibly selected based on the project's cost and energy consumption requirements.

[0202] like Figure 9 As shown, this application embodiment also provides a hydrogen liquefaction system, which may include any of the integrated heat exchangers described above. The hydrogen liquefaction system also includes a controller, a hydrogen inlet regulating valve 17 disposed on or upstream of the inlet connector 27, and a hydrogen outlet regulating valve 18 disposed on or downstream of the outlet connector 37. The hydrogen inlet regulating valve 17 and the hydrogen outlet regulating valve 18 are electrically connected to the controller.

[0203] The hydrogen liquefaction system can achieve the technical effects of the integrated heat exchanger implementation by setting up the integrated heat exchanger.

[0204] In this embodiment, by setting head cooling bypasses and regulating valves on the cold fluid main circuit and the hydrogen main circuit, comprehensive control of head jacket cooling and operating conditions is achieved. Specifically, the cold side main circuit is formed between the cold side inlet 10 and the cold side outlet 11; a first cooling bypass 12 is set on the cold side inlet 10 side, and a second cooling bypass 14 is set on the cold side outlet 11 side; a first bypass regulating valve 13 and a second bypass regulating valve 15 are respectively set on the corresponding bypasses to regulate the flow rate of cold fluid entering each head jacket, thereby achieving jacket cooling control based on the above; in addition, a hydrogen inlet regulating valve 17 and a hydrogen outlet regulating valve 18 are respectively set at the hydrogen inlet (specifically on or upstream of the inlet connector 27) and the hydrogen outlet (specifically on or downstream of the outlet connector 37) to adjust the hydrogen flow rate, pressure difference, and operating point.

[0205] Through the above-mentioned main circuit and bypass regulation, it is possible to achieve comprehensive optimization of end cap temperature, overall pressure drop and cooling consumption while ensuring positive hydrogen conversion rate.

[0206] Furthermore, the aforementioned valves and sensors can be electrically connected to the controller, which can store the aforementioned correspondences. The controller integrates multiple signal input and output interfaces, enabling it to collect key parameters such as temperature, pressure, flow rate, and positive hydrogen content in real time, and automatically output valve adjustment commands based on the algorithm formed by the correspondences. The system's automation level is greatly improved, eliminating the need for real-time manual monitoring, significantly reducing the number of operators, and lowering labor costs.

[0207] The hydrogen inlet and outlet regulating valves and the dual bypass regulating valves form a flow-temperature dual closed-loop control system, which can quickly respond to disturbances such as hydrogen flow fluctuations. Through the coordinated regulation of multiple valves, the system pressure, temperature, conversion rate and other parameters can be restored to stability in a short time. Compared with traditional manual regulation, the system stability is greatly improved, and the conversion rate and pressure drop remain stable.

[0208] The controller has multiple sets of typical operating condition parameters built in, including preset values ​​such as valve opening and target temperature under various operating conditions. Operators can switch operating conditions with one click through the touch screen. It can quickly adapt to the intermittent flow fluctuation characteristics of new energy hydrogen production. Switching from full load to low load does not require re-adjustment, making operation convenient and expanding the application scenarios of the system.

[0209] By upgrading the local control of the integrated heat exchanger to the global control of the hydrogen liquefaction system, the controller is linked with the upstream and downstream systems and can dynamically adjust the system operating parameters according to the quality of upstream feed gas and downstream hydrogen storage demand. System-level collaborative optimization significantly improves the overall liquefaction efficiency, while reducing load conflicts between equipment, greatly reducing the system failure downtime rate, and improving overall operating efficiency.

[0210] The controller stores a method for verifying the heat transfer area of ​​the inlet and outlet end caps. This verification method includes: determining the target heat transfer area (inner surface area of ​​the inlet end cap jacket layer 24) based on the reaction heat power, the logarithmic mean temperature difference between the hot and cold ends, and the overall heat transfer coefficient. ), making the actual heat exchange area The value is greater than or equal to the target heat exchange area. The specific determination process for each parameter can be found in the detailed description of the above embodiments, and will not be elaborated upon here.

[0211] All articles and references disclosed in this application, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified element, component, part, or step, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute included by “may” is optional. Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The use of “a” or “an” to describe an element, component, part, or step does not imply exclusion of other elements, components, parts, or steps.

[0212] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from the others. Similar or identical parts between embodiments can be referred to interchangeably. The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated heat exchanger, characterized in that, The integrated heat exchanger includes: a core and an inlet end cap and an outlet end cap respectively sealed and connected to both ends of the core; the core is the core of a printed circuit board type heat exchanger. The inlet head includes a first inlet shell and a second inlet shell spaced apart from each other. The first inlet shell is used to form an inlet catalyst packing cavity. An inlet head jacket layer is formed between the first inlet shell and the second inlet shell. The second inlet shell is provided with a first bypass inlet and a first bypass outlet. Cold fluid flows in through the first bypass inlet, flows through the inlet head jacket layer, and flows out through the first bypass outlet. The inlet head is provided with an inlet connector on the side away from the core body. The inlet connector is connected to the inlet catalyst packing cavity. The outlet end cap includes a first outlet shell and a second outlet shell spaced apart inside and outside. The first outlet shell is used to form an outlet catalyst packing cavity. An outlet end cap jacket layer is formed between the first outlet shell and the second outlet shell. The second outlet shell is provided with a second bypass inlet and a second bypass outlet. Cold fluid flows in through the second bypass inlet, flows through the outlet end cap jacket layer, and flows out through the second bypass outlet. The outlet end cap is provided with an outlet connector on the side away from the core body. The outlet connector is connected to the outlet catalyst packing cavity. A first filter assembly is disposed between the inlet end cap and the core; and / or, a second filter assembly is disposed between the outlet end cap and the core; and / or, the first inlet housing and the second inlet housing are respectively provided with inlet mounting holes for installing the inlet connector, the inlet connector is sealed within the inlet mounting holes, and a third filter assembly is disposed in the inlet connector; and / or, the first outlet housing and the second outlet housing are respectively provided with outlet mounting holes for installing the outlet connector, the outlet connector is sealed within the outlet mounting holes, and a fourth filter assembly is disposed in the outlet connector; the first filter assembly, the second filter assembly, the third filter assembly, or the fourth filter assembly comprises, in sequence, a first pressure-bearing support layer, a fine filter layer, and a second pressure-bearing support layer, wherein the sieve pore size of the fine filter layer is smaller than the minimum particle size of the catalyst.

2. The integrated heat exchanger as described in claim 1, characterized in that, The first inlet housing is provided with an inlet catalyst packing port and an inlet catalyst discharge port communicating with the inlet catalyst packing chamber, wherein the inlet catalyst packing port is located above the inlet catalyst discharge port; and / or, The first outlet housing is provided with an outlet catalyst packing port and an outlet catalyst discharge port that communicate with the outlet catalyst packing chamber, and the outlet catalyst packing port is located above the outlet catalyst discharge port.

3. The integrated heat exchanger as described in claim 1, characterized in that, An inlet flow equalization orifice plate is arranged in the inlet catalyst packing cavity along the fluid flow direction; and / or, an outlet flow equalization orifice plate is arranged in the outlet catalyst packing cavity along the fluid flow direction. When there are multiple inlet flow equalization orifice plates, the multiple inlet flow equalization orifice plates are arranged at intervals along the fluid flow direction; And / or, when there are multiple outlet flow equalization orifice plates, the multiple outlet flow equalization orifice plates are arranged at intervals along the fluid flow direction.

4. The integrated heat exchanger as described in claim 1, characterized in that, The catalyst bed formed in the inlet catalyst packing chamber and the catalyst bed formed in the outlet catalyst packing chamber differ in at least one of the following: catalyst type, packing height, bed porosity, and catalyst particle size.

5. The integrated heat exchanger as described in claim 4, characterized in that, The catalyst in the inlet catalyst packing chamber is different from the catalyst in the outlet catalyst packing chamber. The catalyst in the inlet catalyst packing chamber includes an iron-based catalyst or a noble metal supported catalyst; the catalyst in the outlet catalyst packing chamber includes a rare earth oxide catalyst or a composite catalyst.

6. The integrated heat exchanger as described in claim 1, characterized in that, The core is provided with a cold-side inlet for cold fluid to flow into the core and a cold-side outlet for discharging the cold fluid flowing through the core. The integrated heat exchanger further includes: a first cooling bypass, one end of which is connected to the cold side inlet, and the other end of which is connected to the first bypass inlet; a first bypass regulating valve is provided on the first cooling bypass; and / or, The integrated heat exchanger further includes a second cooling bypass, one end of which is connected to the cold side inlet and the other end of which is connected to the second bypass inlet, and a second bypass regulating valve is provided on the second cooling bypass.

7. The integrated heat exchanger as described in claim 1, characterized in that, The catalyst loading amount in the inlet catalyst packing chamber or the catalyst loading amount in the outlet catalyst packing chamber m cat The following relationship must be satisfied: Among them, Q g This is the hydrogen inlet volumetric flow rate, in m³ / s. 3 / s,k v The effective volume reaction rate constant is expressed in seconds. -1 X is the target conversion rate, ρ b The catalyst bulk density is expressed in kg / m³. 3 .

8. A hydrogen liquefaction system, characterized in that, The hydrogen liquefaction system includes the integrated heat exchanger as described in any one of claims 1 to 7, and the hydrogen liquefaction system further includes a controller, a hydrogen inlet regulating valve disposed on or upstream of the inlet connector, and a hydrogen outlet regulating valve disposed on or downstream of the outlet connector, wherein the hydrogen inlet regulating valve and the hydrogen outlet regulating valve are electrically connected to the controller.

9. The hydrogen liquefaction system as described in claim 8, characterized in that, The controller stores a method for verifying the heat exchange area of ​​the inlet end cap and the outlet end cap. The verification method includes: determining the target heat exchange area based on the reaction heat power, the logarithmic mean temperature difference between the hot end and the cold end, and the overall heat transfer coefficient, so that the actual heat exchange area is greater than or equal to the target heat exchange area.

Images