CN116675182A - Reformer and design parameter optimization method thereof - Google Patents
Reformer and design parameter optimization method thereof Download PDFInfo
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- CN116675182A CN116675182A CN202310593756.0A CN202310593756A CN116675182A CN 116675182 A CN116675182 A CN 116675182A CN 202310593756 A CN202310593756 A CN 202310593756A CN 116675182 A CN116675182 A CN 116675182A
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- 238000005457 optimization Methods 0.000 title claims abstract description 55
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- 239000001257 hydrogen Substances 0.000 claims abstract description 100
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 100
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 83
- 230000003197 catalytic effect Effects 0.000 claims abstract description 62
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
- C01B3/323—Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents
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- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
- C01B3/323—Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents
- C01B3/326—Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents characterised by the catalyst
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
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- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/02—Processes for making hydrogen or synthesis gas
- C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
- C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
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- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/08—Methods of heating or cooling
- C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/08—Methods of heating or cooling
- C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
- C01B2203/085—Methods of heating the process for making hydrogen or synthesis gas by electric heating
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Abstract
The invention discloses a reformer and a design parameter optimization method thereof, the reformer comprises a shell and an induction coil arranged outside the shell, a catalytic bed with two sides separated by a porous partition plate is arranged inside the shell, a heating body is arranged in the catalytic bed, a pressurizing heating sheet which is arranged in an outward protruding way is arranged on the outer wall of the heating body, and a catalyst is filled in a gap area between the outer wall of the heating body and the pressurizing heating sheet and the inner wall of the shell in the catalytic bed; the design parameter optimization method comprises the step of optimizing and obtaining the optimal design parameters by adopting a simulation combined performance prediction model. The invention aims to make the raw material fully converted, fully exert the catalytic performance of the catalytic bed and realize the production of more reformed hydrogen under the condition of less heat input.
Description
Technical Field
The invention relates to the technical field of hydrogen production by reformers, in particular to a reformer and a design parameter optimization method thereof.
Background
The hydrogen energy is a green energy source capable of realizing zero pollution and zero emission. The tubular reformer is one of the high-efficiency devices for producing hydrogen from methanol, and has wide application. The methanol steam absorbs heat in the reformer to realize catalytic hydrogen production (MSR) reaction, and the method has the advantages of low reforming temperature (200-300 ℃), simple process operation, high hydrogen content, low CO content and the like, and is important for obtaining high-purity hydrogen and reducing the product reprocessing cost. In recent years, the hydrogen production by adopting the tubular reformer has great development prospect in miniaturized movable application scenes such as a mobile power supply, a ship and the like, and is paid attention to.
The heat supply effectiveness is closely related to the performance of the reformer, and the improvement of the heat supply effectiveness of the catalytic bed mainly has two measures, namely, the increase of the effective heat exchange area with the heat transfer medium and the reduction of the heat loss of the heat transfer medium. The tubular reformer usually adopts a sleeve-type structure, the catalytic bed is filled by catalyst particles, high-temperature gas is used as a heat source for supplementing heat, and a temperature conical cold spot is easy to form due to high thermal resistance and small effective heat exchange area, so that the catalytic efficiency of the catalytic bed is reduced.
The double-sleeve reformer with two inner and outer heating channels is designed in consideration of increasing effective heat exchange area You Yongkang (You Yongkang. Development of small integrated methanol hydrogen production tubular reactor [ D ]. Zhejiang university of industry, 2020.), and compared with a single-sleeve reformer, the double-sleeve reformer has obvious improvement on heat transfer performance and reaction performance, further Guruu et al (Guruke V, ogurleke A, strickland F. Design of a methanol reformer for on-board production of hydrogen as fuel for a 3kW High-Temperature Proton Exchange Membrane Fuel Cell power system [ J ]. International journal of hydrogen energy,2020,45 (56): 31745-31759.) designs a catalytic bed which is formed by filling a catalyst tube bundle, and the periphery adopts reformer monomers with four circular arc combustion channels for heating, so that hydrogen meeting the operation of 200W High-temperature fuel cell can be produced under the design working condition. Meanwhile, the reduction of environmental heat loss is considered, wu et al (Wu W, yang S B, hwang J, et al design, modeling, and optimization of a lightweight MeOH-to-H2 processor [ J ]. International journal of hydrogen energy,2018,43 (31): 14451-14465) adopt an inner tube reflux mode in a multi-tube annular film reformer to burn purified product gas, so that continuous hydrogen production heat supply is realized, external heat input is not needed after the reformer is started, and the gas combustion is very easy to form a local high-temperature region inside. Nehe et al (Nehe P, reddy V M, kumar S. Investments on a new internally-heated tubular packed-bed methane-steam reform [ J ]. International Journal of Hydrogen Energy,2015,40 (16): 5715-heated tubular packed.) propose using an electrical heating rod to achieve internal heating which reduces the overall temperature gradient of the reformer compared to external heating, and internal heating reforming reduces ambient heat loss and improves energy utilization and methanol conversion at the same heating temperature. Compared with the resistance heating of a heating rod, the electromagnetic heating has the advantages of rapid heating, high energy efficiency, multiple structures of heating elements and the like, has better application prospect in a chemical reactor, is Zhang Gucheng and the like (Zhang Gucheng, wang Feng, peng Longzhao and the like; the characteristic of hydrogen production by reforming methanol steam heated by an internal heat source in a tubular reactor [ J ]. Solar school newspaper, 2021,42 (07): 497-502 ]) adopts electromagnetic heating millimeter-grade iron wires as an internal heat source, and is proved in a miniature tubular reformer experiment, and the mode has better rapid heating starting performance. The internal heating is realized by adopting the cylindrical heating bodies such as the electric heating rod, the iron wire and the like, and although the heat environmental loss can be reduced, the effective heat exchange area of the heating body and the catalytic bed is small in the radial direction, the catalytic bed is insufficient in heat supplement, the whole catalytic performance is still not good, and the heat supply energy efficiency level still needs to be improved.
Disclosure of Invention
The invention aims to solve the technical problems: aiming at the problems in the prior art, the invention provides a reformer and a design parameter optimization method thereof, which aims at ensuring that the more the raw material is converted, the more the catalytic performance of a catalytic bed is fully exerted, and the more reformed hydrogen is produced under the condition of less heat input.
In order to solve the technical problems, the invention adopts the following technical scheme:
the reformer comprises a shell and an induction coil arranged outside the shell, wherein a catalytic bed is arranged inside the shell, two sides of the catalytic bed are partitioned by a porous partition plate, a heating body is arranged in the catalytic bed, a pressurizing heating piece which is arranged in an outward protruding mode is arranged on the outer wall of the heating body, and a catalyst is filled in a gap area between the outer wall of the heating body and the pressurizing heating piece and the inner wall of the shell in the catalytic bed.
Optionally, the pressurizing heating piece is annular structure, and evenly overlaps on the outer wall of heat-generating body, the quantity that is equipped with the pressurizing heating piece on the outer wall of heat-generating body is a plurality of.
Optionally, the shell is equipped with evenly distributed's a plurality of guide vanes on the inner wall that is located catalytic bed department, the guide vane is annular structure and inlays on the inner wall of locating the shell, and stagger arrangement between a plurality of guide vanes and a plurality of pressure boost heating piece.
Optionally, the pressurizing heating sheet and the heating body are of an integrated structure made of ferromagnetic materials.
In addition, the invention also provides a design parameter optimization method of the reformer, which comprises the following steps:
s101, determining design parameters of a reformer;
s102, building a service performance simulation model for obtaining service performance of the reformer in a simulation mode based on design parameters of the reformer and working condition parameters of the reformer during hydrogen production in service;
s103, manufacturing a sample of the reformer based on design parameters of the reformer, respectively obtaining experimental values of service performance indexes of the sample of the reformer under the same design parameters and simulation values of the service performance indexes of the service performance simulation model through orthogonal experiments of the design parameters, and judging that the service performance simulation model passes verification and jumps to the step S104 if the difference between the experimental values of the service performance indexes and the simulation values meets the requirements; otherwise, step S102 is skipped to readjust the service performance simulation model;
s104, taking the service performance simulation model as a basis, taking different combinations of design parameters as input to perform service performance simulation experiments to obtain simulation values of service performance indexes of the reformer under the different combinations of design parameters, and constructing the different combinations of design parameters and the simulation values of the corresponding service performance indexes to obtain a design and performance parameter data set;
S105, establishing a reformer performance prediction model for realizing the mapping relation between design parameters of different combinations and evaluation values of corresponding service performance indexes by utilizing the design and performance parameter data set; taking the design parameters of different combinations as input of a reformer performance prediction model based on the design and performance parameter data set to obtain a service performance evaluation value, taking the same design parameters as a service performance simulation model to obtain a simulation value of a service performance index, and training and optimizing the reformer performance prediction model by utilizing the simulation value of the service performance index and the difference value between the service performance evaluation values until the simulation value of the service performance index and the difference value between the service performance evaluation values are smaller than a set value, thereby obtaining a trained reformer performance prediction model;
s106, determining the weight of each service performance index element in the service performance index, and constructing a service performance optimization objective function formed by weighted summation of each service performance index element;
and S107, optimizing the service performance optimization objective function by adopting an optimization algorithm to obtain an optimal value of the design parameter.
Optionally, when determining the design parameters of the reformer in step S101, the determined design parameters of the reformer include an inlet flow velocity V in The contact ratio zeta of the pressurizing heating sheet and the angle alpha of the pressurizing heating sheet, wherein the contact ratio zeta of the pressurizing heating sheet refers to the ratio of the length of the pressurizing heating sheet and the length of the flow deflector, which are overlapped in the radial direction, to the annular width of the catalytic bed, and the angle alpha of the pressurizing heating sheet refers to the included angle between the pressurizing heating sheet and the heating body, which faces to the inlet side direction.
Optionally, the calculating function expression of the overlap ratio ζ of the pressurizing heat generating sheet is:
in the above, h fin Represents the height of the pressurizing heating sheet (51), D in Represents the internal diameter, d, of the catalytic bed (4) heat The inner diameter of the heating element (5) is shown.
Optionally, each service performance index element in the service performance index in the step S106 comprises an electro-hydrogen energy conversion ratio lambda and a temperature difference T before and after conversion dif Flow energy loss P pa Wherein the temperature before and after conversionDifference T dif Refers to the temperature difference between the input end and the output end of the reformer, the electro-hydrogen energy conversion ratio lambda and the flow energy loss P pa The expression of the calculation function of (c) is:
P pa ＝ΔP×V in ×S，
in the above, P H2 For the estimated power of the hydrogen produced, P coil The electric power provided for the induction coil, delta P is the pressure difference between the inlet and the outlet of the reformer, V in S is the inlet flow rate and S is the inlet and outlet area of the reformer.
Optionally, after step S107, the method further includes calculating, for a given performance characterization index corresponding to the optimal value of the design parameter, the growth rate of each performance characterization index before and after the design parameter optimization as an evaluation result of the design parameter optimization in combination with the original performance characterization index of the reformer.
Optionally, the given performance characterization index includes a methanol conversion X CH4O Electric hydrogen energy conversion ratio lambda, hydrogen yield lambda H2 ；
Methanol conversion X CH4O The expression of the calculation function of (c) is:
X CH4O ＝(n in -n out )/n in ，
in the above, n in And n out The molar amount of methanol input to and output from the reformer, respectively;
the electric hydrogen energy conversion ratio lambda is calculated by the following functional expression:
in the above, P H2 For the estimated power of the hydrogen produced, P coil The electric power provided to the induction coil.
Compared with the prior art, the invention has the following advantages: according to the invention, the pressurizing heating sheets are arranged on the outer wall of the heating body in an outward protruding way, so that on one hand, the pressurizing heating sheets can be used for increasing the flow blocking pressure, the compressed concentration of the reaction gas is increased along with the increase of the flow blocking pressure, meanwhile, the residence time in the reformer is prolonged, the reaction forward direction is facilitated by longer reaction time and larger reactant concentration, and the more fully converted reaction raw materials are; on the other hand, the pressurizing heating plate can be used for simultaneously increasing the heating area, the heat exchange area and the gas residence time of the heating body so as to achieve better performance, thereby fully playing the catalytic performance of the catalytic bed and realizing the production of more reformed hydrogen under the condition of less heat input.
Drawings
Fig. 1 is a schematic diagram of a reformer according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of a reformer according to a second embodiment of the present invention.
Fig. 3 is a flowchart of a design parameter optimization method of a reformer according to a second embodiment of the present invention.
Fig. 4 is a diagram illustrating an artificial neural network modeling structure according to a second embodiment of the present invention.
FIG. 5 is a graph showing the relationship between the inlet flow rate and the outlet temperature in the second embodiment of the present invention.
FIG. 6 is a graph showing the relationship between the inlet flow rate and the outlet flow rate in the second embodiment of the present invention.
Fig. 7 shows the temperature, hydrogen and pressure distribution in the reformer (before optimization) in the second embodiment of the present invention.
Fig. 8 is an experimental result of a reformer performance prediction model in the second embodiment of the present invention.
Fig. 9 is an optimization iterative process of a reformer performance prediction model in a second embodiment of the invention.
FIG. 10 shows the improvement of the methanol conversion, the electro-hydrogen energy conversion and the hydrogen yield in the second embodiment of the present invention.
Fig. 11 shows reformer temperature, hydrogen concentration, and pressure profile (after optimization) in the second embodiment of the present invention.
Legend description: 1. a housing; 11. a deflector; 2. an induction coil; 3. a porous separator; 4. a catalytic bed; 5. a heating element; 51. pressurizing heating sheet.
Detailed Description
Embodiment one:
as shown in fig. 1, this embodiment provides a reformer, including shell 1 and locate the outside induction coil 2 of shell 1, the inside catalytic bed 4 that is equipped with both sides and cuts off through porous baffle 3 of shell 1, be equipped with heat-generating body 5 in the catalytic bed 4, be equipped with the pressure boost heating piece 51 that outwards protrusion was arranged on the outer wall of heat-generating body 5, just in the catalytic bed 4 in the space region between the outer wall and the shell 1 inner wall of heat-generating body 5 and pressure boost heating piece 51 between the catalyst. In this embodiment, the casing 1 has the same structure as a common tubular reformer, and the main body is cylindrical, with an inlet on one side and an outlet on the other side. In this embodiment, the heating element 5 and the pressurizing heating sheet 51 are an integral structure made of ferromagnetic material and are disposed at the center of the reformer.
In this embodiment, the pressurization heating piece 51 is annular structure, and evenly overlaps on locating the outer wall of heat-generating body 5, the quantity that is equipped with the pressurization heating piece 51 on the outer wall of heat-generating body 5 is a plurality of, and the pressurization effect is better, increases the area that generates heat, heat transfer area and the gaseous dwell time effect of heat-generating body better.
The working principle of the reformer for producing hydrogen by reforming methanol and steam in the embodiment is as follows: the heat energy of the heating body 5 and the pressurizing heating piece 51 is supplied by electromagnetic induction, the induction coil 2 is uniformly wound outside a section corresponding to the catalytic bed 4 on the outer wall of the shell 1, a certain frequency current is introduced into the induction coil 2, temperature feedback is established by the temperature of the probe, and the current value is regulated to maintain the operation temperature of the reformer, so that heat balance is realized. In the electromagnetic field environment, the heating element 5 and the pressurizing heating sheet 51 generate eddy current heating, the heating element 5 and the pressurizing heating sheet 51 are positioned on the central axis of the reformer upwards, when methanol vapor flowing in from the inlet flows through the area of the catalytic bed 4, the hydrogen production reaction smoothly proceeds under the combined action of the catalysis of the catalyst and the heat exchange with the heating element 5 and the pressurizing heating sheet 51, and the prepared hydrogen can flow out from the outlet on the other side. In this embodiment, the reformer is based on the conventional heating element, the pressurizing heating plate 51 is added to affect the gas circulation pressure, the pressurizing heating plate 51 can increase the heat generating volume of the heating element 5 in the electromagnetic field, and meanwhile, the heat exchange area between the heating element 5 and the catalytic bed and the reaction gas is increased, and the flow guiding plate changes the gas flow direction, so that the reaction gas contacts with the heating element 5 and the pressurizing heating plate 51 with high temperature as much as possible.
Embodiment two:
this embodiment is a further improvement over the first embodiment. As shown in fig. 2, in this embodiment, a plurality of evenly distributed flow guiding sheets 11 (a plurality of flow guiding sheets 11 and a plurality of pressurizing heat generating sheets 51 are both evenly distributed in the area where the catalytic bed 4 is located) are disposed on the inner wall of the housing 1, the flow guiding sheets 11 are in a ring structure and are embedded on the inner wall of the housing 1, and the plurality of flow guiding sheets 11 and the plurality of pressurizing heat generating sheets 51 are staggered, so that a meshed shape is formed in structure. In the embodiment, a plurality of guide vanes 11 which are uniformly distributed on the inner wall of the shell 1 positioned at the catalytic bed 4 are added, so that the supercharging effect is better. The reaction gas enters from the inlet at a certain speed, and under the condition of no disturbance, the flow of the reaction gas can be regarded as approximate straight line, and when the flow guide sheet 11 is further added, the flow direction of the gas can be changed, so that most of the gas is tightly attached to the pressurizing heating sheet 51, the heat absorption effect of the reaction gas is increased, and the pressure of the reaction gas is also increased.
In this embodiment, the housing 1 and the baffle 11 are made of a heat-resistant insulating material.
As shown in fig. 3, the present embodiment further provides a method for optimizing design parameters of the foregoing reformer, including:
S101, determining design parameters of a reformer; based on design parameters of the reformer and by combining the structure of the reformer, the uniqueness of the structure of the reformer can be determined, and the parameterization of the structure of the reformer and the operation thereof can be realized;
s102, building a service performance simulation model for obtaining service performance of the reformer in a simulation mode based on design parameters of the reformer and working condition parameters of the reformer during hydrogen production in service;
s103, manufacturing a sample of the reformer based on design parameters of the reformer, respectively obtaining experimental values of service performance indexes of the sample of the reformer under the same design parameters and simulation values of the service performance indexes of the service performance simulation model through orthogonal experiments of the design parameters, and judging that the service performance simulation model passes verification and jumps to the step S104 if the difference between the experimental values of the service performance indexes and the simulation values meets the requirements; otherwise, step S102 is skipped to readjust the service performance simulation model; the correctness of the simulation model can be verified and determined through the sample of the reformer;
for the sample of the reformer, the experimental platform constructed in this embodiment provides electric energy through a DC power supply, and uses a ZVS converter to realize DC/AC conversion to form alternating current, and an induction coil generates an alternating electromagnetic field to heat the reformer. The argon cylinder provides the gas to be heated to approximately represent the methanol vapor that is admitted. The reformer is filled with commercial copper catalyst, the main component is CuO-ZnO-Al 2 O 3 The heating element 5 with the pressurizing heating plate 51 and the heating element 5 without the pressurizing heating plate 51 of the traditional reformer are adopted to supply heat to the catalytic bed 4, when the constant power of the power supply is 25W, the gas inlet flow rate is regulated by the regulating valve, the temperature and the speed of the gas at the outlet of the reformer are measured, and the comparison analysis is carried out with the simulation result under the same parameters.
S104, taking the service performance simulation model as a basis, taking different combinations of design parameters as input to perform service performance simulation experiments to obtain simulation values of service performance indexes of the reformer under the different combinations of design parameters, and constructing the different combinations of design parameters and the simulation values of the corresponding service performance indexes to obtain a design and performance parameter data set;
s105, establishing a reformer performance prediction model for realizing the mapping relation between design parameters of different combinations and evaluation values of corresponding service performance indexes by utilizing the design and performance parameter data set; taking the design parameters of different combinations as input of a reformer performance prediction model based on the design and performance parameter data set to obtain a service performance evaluation value, taking the same design parameters as a service performance simulation model to obtain a simulation value of a service performance index, and training and optimizing the reformer performance prediction model by utilizing the simulation value of the service performance index and the difference value between the service performance evaluation values until the simulation value of the service performance index and the difference value between the service performance evaluation values are smaller than a set value, thereby obtaining a trained reformer performance prediction model;
S106, determining the weight of each service performance index element in the service performance index, and constructing a service performance optimization objective function formed by weighted summation of each service performance index element;
and S107, optimizing the service performance optimization objective function by adopting an optimization algorithm to obtain an optimal value of the design parameter.
In this embodiment, when the service performance simulation model for obtaining the service performance of the reformer in a simulation manner is built in step S102, taking into consideration that the reformer structure has cylindrical axisymmetry, the system model 1 is operated in COMSOL Multiphysics 5.6.5.6 in a two-dimensional axisymmetric manner: 1, constructing a simulation model, wherein the simulation model is coupled with the transmission of concentrated substances, the heat transfer of fluid, the flow of free and porous media, a magnetic field and a chemical interface. The thermal conductivity of the catalyst bed 4 was set to 0.454W/(mK), the porosity was set to 0.35, and the inlet water-alcohol ratio was set to 1. A 20KHz current is introduced into the coil, and the temperature T is measured by a probe heat Feedback is established for the target temperature and the current value is adjusted to provide the desired heat for the reformer system. In consideration of the complex factors associated with the reformer, the simulation involves the calculation of the coupling of the distribution of the material components, the gas flow, the heat balance and the reaction kinetics in the reaction system, and the control equation is as follows.
Mass transfer:
in the method, in the process of the invention,represent gradient, D i Represents the diffusion coefficient (m 2 /s)，c i Represents the substance concentration (mol/m 3),>represents the gradient of the concentration of the substance, u represents the velocity vectorAmount (m/s), ε p Represents the porosity of the catalytic bed of the reformer, R i Expression (mol/(m) 3 ·s))，n i Representing the mole fraction of the substance.
Continuity equation:
in the above formula, u, v, w represent the flow rate of the gas in 3 directions; ρ represents the density of the gas.
Conservation of momentum:
in the above formula, p represents a gas pressure; mu represents the viscosity of the mixed gas; s represents a flow correction term for the reaction gas.
Heat balance:
in the above, C p Represents the gas heat capacity (J/(kg. K)) and K of the reaction zone eq Representing the equivalent thermal conductivity (W/(mK)) of the reaction zone, where K is assumed eq Is equal to the thermal conductivity of the mixed gas,representing the gradient of temperature, Q rea Heat absorption and release quantity Q for methanol reforming hydrogen production reaction heat The heat generation provided for the induction coil 2 is as follows:
Q rea ＝Q SR +Q MD +Q WGS ＝-r sR H SR -r MD H MD -r WGS H WGs ，
Q heat ＝EI，
in the above, Q SR Heat absorption and release for SR reaction, Q MD Suction and discharge for MD reactionHeat, Q wGs Is the heat of absorption and release of WGS reaction, r SR Reaction rate of SR reaction, r MD Reaction rate of MD reaction, r WGS Reaction rate of WGS reaction, H SR Reaction enthalpy of SR reaction, H MD Reaction enthalpy of MD reaction, H WGS Reaction enthalpy for WGS reaction; e represents the effective value of the induced electromotive force of the booster heating element, I represents the induced current, and three reactions are as follows:
SR reaction: CH (CH) 3 OH+H 2 O→CO 2 +3H 2 ，
MD reaction: CH (CH) 3 OH→CO+2H 2 ，
WGS reaction:
the design parameters of the reformer in this example are shown in table 1.
Through tests, the gas circulation pressure, namely the pressurizing effect, can be changed by changing the superposition degree zeta of the pressurizing heat generating pieces and the angle alpha of the pressurizing heat generating pieces, wherein the superposition degree zeta of the pressurizing heat generating pieces refers to the proportion of the length of the pressurizing heat generating pieces 51, which are superposed with the flow guiding pieces 11 in the radial direction, to the annular width of the catalytic bed 4, and the angle alpha of the pressurizing heat generating pieces refers to the included angle between the pressurizing heat generating pieces 51 and the heating bodies 5, which faces the inlet side direction. In addition, the inlet flow velocity V in Is also a fundamental factor in changing the supercharging effect. Therefore, when determining the design parameters of the reformer in step S101 of the present embodiment, the determined design parameters of the reformer include the inlet flow velocity V in The contact ratio zeta of the pressurizing heating sheet refers to the ratio of the length of the pressurizing heating sheet 51 overlapped with the guide sheet 11 in the radial direction to the annular width of the catalytic bed 4, and the angle alpha of the pressurizing heating sheet refers to the included angle between the pressurizing heating sheet 51 and the heating body 5 facing the inlet side direction.
In this embodiment, assuming that the heights of the guide vane 11 and the booster heat generating vane 51 are equal, the calculation function expression of the booster heat generating vane overlap ζ is:
in the above, h fin Indicating the height of the pressurizing heat generating fin 51, D in Represents the internal diameter, d, of the catalytic bed 4 heat The inner diameter of the heating element 5 is shown.
In the embodiment, the service performance index elements in the service performance index in the step S106 include the electro-hydrogen energy conversion ratio lambda and the temperature difference T before and after conversion dif Flow energy loss P pa Wherein the temperature difference T between before and after conversion dif Refers to the temperature difference between the input end and the output end of the reformer, the electro-hydrogen energy conversion ratio lambda and the flow energy loss P pa The expression of the calculation function of (c) is:
P pa ＝ΔP×V in ×S，
in the above, P H2 For the estimated power of the hydrogen produced, P coil The electric power provided for the induction coil 2, ΔP is the reformer inlet-outlet pressure difference, V in For inlet flow rate, S is reformer inlet-outlet area, wherein:
P H2 ＝λ H2 ×λ p ，
in the above, lambda H2 For hydrogen yield, g/min, lambda p For estimating the ratio, the value may be empirically determined, for example, the prior art describes an estimated power generation P of hydrogen when the hydrogen yield is about 375sccm H2 About 67W.
In this embodiment, steps S105 and S106 are respectively the construction and training process of the reformer performance prediction model. The reformer performance prediction model may employ a desired machine learning model as desired. Considering that the modeling of the artificial neural network is widely applied to engineering problems, the single hidden layer BP neural network can be theoretically fitted Any nonlinear function can meet the precision requirement of engineering in practical application, so that a single hidden layer BP neural network is adopted in the embodiment to establish a predictive model of reformer system performance. Respectively at inlet flow velocity V in The superposition degree zeta of the pressurizing heating sheet, the angle alpha of the pressurizing heating sheet is taken as an input layer, and the temperature difference T before and after conversion is converted by the electric-hydrogen energy conversion ratio lambda dif Flow energy loss P pa For the output layer, its modeling structure is shown in fig. 4.
Under the condition of ensuring normal circulation of reaction gas, through simulation test, setting the upper and lower boundaries of the angle alpha of the pressurizing heating plate to be 75 degrees and 105 degrees respectively, constructing a BP neural network model input data set as shown in table 2, performing performance prediction model establishment by 420 groups of data of orthogonal experiments (wherein the coincidence degree is realized by changing the height of the pressurizing heating plate), and setting the random distribution proportion of the data set to 80% of a training set, 10% of a verification set and 10% of a test set based on a MATLAB neural network tool box in order to ensure the randomness and verification and prediction capability of model training. Based on the empirical formula:
wherein n is the number of neurons in the hidden layer, n i To input the neuron number, n 0 In order to output the neuron number, b is a constant between 1 and 10, the embodiment selects the hidden layer neuron number to be 3, and the learning function, the training function and the error training function all use default functions with time shortage, and the training is repeated until the neural network model meets the precision requirement.
Table 2: the training, validation and test models input a dataset.
The relationship between the inlet flow rate and the outlet temperature of the reformer is shown in fig. 5 under the two structures of the heating element 5 with or without the pressurizing heating element 51, and as can be seen from fig. 5, the outlet gas temperature of the reformer is reduced as the inlet flow rate is increased, and under the same power supply, the outlet gas temperature of the reformer which is complemented by the heating element 5 with the pressurizing heating element 51 is higher, which indicates that compared with the common cylindrical heating element (the heating element 5 without the pressurizing heating element 51), the pressurizing heating element structure improves the heat supply effect of the reformer on the gas, and is beneficial to the heat absorption of the gas in the reformer. The pressurizing heating element increases gas circulation resistance and heat exchange area, changes a gas circulation path, changes a cylindrical direct current type into a curve type, ensures that gas is heated in the reformer for a longer time and a higher temperature, and simultaneously shortens the distance between the heating element and the coil by the pressurizing heating element, so that the induction heat production efficiency is higher and the heat supply effect of the reformer is better. As shown in fig. 6, the relationship between the inlet flow rate and the outlet flow rate of the reformer is shown in fig. 6, and as the inlet flow rate increases, the outlet flow rate of the reformer increases, and the outlet flow rate is larger than the inlet flow rate, and at the same inlet flow rate, the outlet flow rate of the reformer of the booster heat generating body structure (heat generating body 5 having booster heat generating fins 51) is larger than that of the cylindrical heat generating body, which is mainly caused by the booster effect of the booster heat generating body and the increase in the effective heat supply amount. The heating element 5 with the pressurizing heating piece 51 increases the resistance of the gas flowing in the catalytic bed section, the pressure in the pressurizing heating element structural reformer is larger under the same inlet flow rate, the gas is compressed, the concentration is increased, the flowing speed is reduced, the pressure and the temperature of the gas are relieved and increased near the outlet end of the catalytic bed, the gas molecules are rapidly diffused, the molecular kinetic energy and the internal energy are larger, and a slightly higher outlet flow rate is shown. As can be seen from comparison of the experimental and simulation results, the experimental and simulation results have the same variation trend, the overall error is less than 10%, the error mainly comes from measurement error, reformer sample manufacturing error, the model ignores heat generation and other errors of the catalyst under the action of an electromagnetic field, and the overall error has small influence. Therefore, compared with the common cylindrical heating element, the heating element structure of the heating element 5 with the pressurizing heating sheet 51 prolongs the gas flow path, increases the flow resistance, the heat exchange area and the gas flow time, and improves the overall heating effect. Moreover, compared with experimental tests and simulation results, the data consistency of the two is higher, which indicates that the simulation model of the reformer system constructed in the method has higher accuracy and can be used for the performance prediction and parameter optimization research of the reformer system.
In this example, according to the initial design parameters (table 1, ζ=0, α=90°, V in =0.8 m/s), simulation results of reformer system reaction are shown in fig. 7. The reactant gas flows in the reformer to form a pressure drop, the pressure distribution in the reformer is shown in fig. 7 (a), and is mainly influenced by the catalyst particle filling and the arrangement of the pressurizing heat generating fins, and under the action of the catalyst particle filling and the pressurizing heat generating fins, the pressure distribution of the total gas quantity in the radial direction is approximately uniform, and no obvious pressure profile exists. The gas pressure gradually decreases as the gas continues to flow in the axial direction. The pressurizing heating piece design enables the flow path of the reaction gas to be increased, the conventional direct-current type flow path is changed into a curve type flow path, the flow obstruction and the reaction time are increased, the longer reaction contact time is helpful for improving the methanol conversion rate, but the flow obstruction is increased at the same time, and the power consumption of the methanol water vapor raw material transportation is increased. The methanol steam reforming hydrogen production reaction is sensitive to temperature and is a strong endothermic reaction, the temperature distribution in the reformer is shown in (b) of fig. 7, and under the influence of a magnetic field generated by an induction coil, vortex is formed on the surface of a pressurizing heating element to act with self resistance to generate joule heat. As the only heat source in the reformer, the whole booster heating body is in a relatively high temperature state, the temperature of the catalytic bed gradually decreases along with the increase of the distance from the booster heating body in the radial direction, and the average temperature of the catalytic bed is in a distribution rule of decreasing firstly and then rising in the axial direction. The coils are uniformly wound on the reformer, the heat generation density of the booster heating body in the axial direction can be considered to be approximately equal, namely, the heat provided by the catalytic bed is approximately equal in the axial direction, and the heat absorption of the reforming reaction mainly occurs near the inlet section of the catalytic bed, so that the temperature distribution of the catalytic bed in the axial direction is not uniform. As the reforming reaction proceeds, the reactant gradually decreases in the axial direction, the heat absorption amount also gradually decreases, and the temperature of the booster heat generator entirely increases in the axial direction. In the radial direction, the end part of the pressurizing heating sheet is closest to the coil, the magnetic field intensity and the heat generation density of the end part are maximum under the action of skin effect, meanwhile, the end part of the pressurizing heating sheet and the catalytic bed exchange heat sufficiently, and the heat exchange and heat generation accumulation are coordinated Under the same action, the position of the highest temperature of the booster heating body is positioned on the central axis, and the position and the temperature value of the highest temperature deviate from the setting of the detection point under the combined action of disturbance heat exchange and heat generation at the outlet end. In the catalytic bed, the reforming reaction of methanol steam is carried out to produce a large amount of hydrogen gas, and the hydrogen gas concentration distribution is shown in fig. 7 (c). The reaction rate increases along with the temperature rise, the molecular chemical bond of the methanol vapor is more easily dissociated in a high-temperature area close to the booster heating element, the gas molecules are more active, the reaction rate is faster under the action of a catalyst, and the hydrogen concentration is higher, so that the hydrogen concentration is distributed in a gradient manner along with the increase of the distance from the booster heating element in the radial direction. The product hydrogen gradually accumulates as the reforming reaction proceeds in the axial direction, and the hydrogen concentration tends to increase in the axial direction as a whole. It can be seen that the overall pressure distribution of the reaction gas in the catalytic bed 4 is approximately uniform in the radial direction, the temperature, the reaction rate and the hydrogen concentration all have a decreasing trend along with the increase of the distance from the booster heating element, the heat absorption quantity of the reactant gradually decreases in the axial direction, the catalytic bed temperature has a change rule of decreasing first and then increasing, and compared with the traditional cylindrical heating element, the booster heating element 41 in the embodiment has a significantly increased heating and effective heat exchange area. The electromagnetic field energy is converted into heat energy by the booster heating body 51, so that sufficient heat can be provided for the reforming hydrogen production reaction in the catalytic bed, and the occurrence condition required by the reaction can be satisfied.
To ensure accuracy of the performance prediction model, a grouping of model input data sets (e.g., the performance prediction model building portion) is trained (80%) with training set 336 sets of data to verify set 42 sets of data (10%) and test set 42 sets of data (10%) and the results are shown in fig. 8. As shown in (a) to (c) of FIG. 8, the experimental value and the predicted value of the electric hydrogen energy conversion ratio are compared, and the electric hydrogen energy conversion ratio is larger than 1 and distributed in the range of 1.8-3, so that the electric hydrogen energy conversion ratio characterizes the conversion level of electric energy converted into hydrogen energy, the regression values of training, verification and test are 0.99619,0.995,0.99559 respectively, and the electric hydrogen energy conversion ratio performance prediction has enough precision. The experimental value of the temperature difference before and after conversion was compared with the predicted value, as shown in FIG. 8 (d) In the reformer, the reaction gas simultaneously carries out reforming reaction conversion heat absorption and heating heat absorption, the product temperature at the outlet is increased to absorb additional heat of the reaction, so that the energy conversion ratio for the reaction in coil energy is reduced, meanwhile, high-temperature tail gas is formed at the outlet, the regression values of training, verification and testing are 0.99916,0.99946,0.99899 respectively, and the temperature difference performance prediction before and after conversion has good precision. As shown in (g) to (i) of fig. 8, the reformer has smaller monomer size and smaller flow energy loss, but when the reformer is suitable for high-power consumption scene to integrate the monomer for use, the formed flow energy loss is not negligible, and the regression values of training, verification and test are 0.99432,0.99501,0.99474 respectively, so that the accuracy of the flow energy loss prediction model meets the use requirement. It can be seen that the established thermoelectric conversion ratio lambda, the temperature difference T between the reforming stage and the reforming stage dif Flow energy loss P pa The accuracy of the predictive model of (c) meets the use requirements and can be used for optimizing the energy conversion level of the reformer.
To obtain better reformer performance, inlet flow rate V is based on a reformer system performance prediction model in And optimizing design variables such as the coincidence degree zeta of the pressurizing heating sheet, the angle alpha of the pressurizing heating sheet and the like. The primary goal of the reformer is to convert methanol steam into hydrogen, and in energy relationship, the level of conversion of electrical energy into hydrogen energy is of paramount importance, and the reformer should have a sufficiently large electrical-to-hydrogen energy conversion ratio. In addition, the reformer should have a sufficiently low temperature difference before and after conversion to reduce the heat loss of the product and the cooling cost, and the pressurizing heating plate makes the reaction gas have longer reaction time and also brings more flow energy loss. According to the importance ranking, the three targets are ranked into an electro-hydrogen energy conversion ratio, a temperature difference before and after conversion and a flow energy loss.
In this embodiment, step S106 determines the weights of all service performance index elements in the service performance index, and when constructing a service performance optimization objective function formed by weighted summation of all service performance index elements, normalizes the electro-hydrogen energy conversion ratio, the temperature difference before and after conversion, and the flow energy loss, and respectively assigns weights-0.5,0.3,0.2, so that the electro-hydrogen energy conversion ratio is as large as possible, the temperature difference before and after conversion, and the flow energy loss are as small as possible as an optimization objective, and the amount of the service performance optimization objective function is established as follows:
Optimizing the objective function by using a genetic algorithm GA, wherein the iterative process is shown in fig. 9, the objective function is converged when the iterative step number reaches more than 70, and the design variable value is obtained by optimizing calculation, wherein the design variable value is the overlap ratio zeta=0.467 of the pressurizing heating sheet, the angle alpha=75 DEG of the pressurizing heating sheet, and the inlet flow velocity V in Taking the superposition degree zeta of the pressurizing heating sheet=0.45, the angle alpha of the pressurizing heating sheet=75 DEG and the inlet flow velocity V, wherein the superposition degree zeta of the pressurizing heating sheet is=1.084 m/s in =1.1 m/s. From the design variable optimization results (ζ=0.45, α=75°, V in As can be seen from the initial design variables (table 1, ζ=0, α=90°, V in Compared with 0.8m/s, the contact ratio (ζ) and the methanol water vapor supply flow rate (V in ) The pressurizing heat generating fin angle (alpha) is reduced to an acute angle and is arranged towards the inlet end. The electric hydrogen energy conversion level (target 1) is determined by the ratio of hydrogen energy to electric energy, under the influence of the pressurization of the pressurizing heating piece and a longer flow path, the contact reaction time of the reaction gas and the catalytic bed is increased, and simultaneously, along with the increase of the contact ratio, the heating area and the heat exchange area of the pressurizing heating piece are increased, so that the effective heat exchange amount of the reformer in the radial direction is increased, besides, the angle of the pressurizing heating piece is 75 degrees, an acute angle is formed towards the inlet end of the catalytic bed, the analysis shows that most of reforming heat absorption occurs in the axial direction and is close to the inlet end, and the high temperature area of the pressurizing heating piece is close to the pressurizing heating body in the radial direction, the pressurizing heating piece can timely meet the heat absorption requirement of the inlet section towards the inlet end, and the hydrogen energy conversion output of the reformer is increased under the combined action. Meanwhile, as the contact ratio increases, the distance between the booster heating element and the induction coil is reduced, the efficiency of converting coil electric energy into heat of the booster heating element is higher, the required coil electric energy is less under the same reforming and conversion hydrogen production requirement, and the conversion efficiency of producing hydrogen energy and electric heating energy is improved Under the synergistic effect of the increased rate, the methanol conversion rate, the hydrogen yield and the electro-hydrogen energy conversion ratio (target 1) become larger, and the electro-hydrogen energy conversion level is improved. However, under the better reforming conversion hydrogen production effect, most of raw materials finish reforming hydrogen production conversion in a shorter distance, as the reaction gas continuously flows in the reforming channel, the reaction gas is continuously heated after reforming conversion, the temperature of the product gas at the outlet end of the reformer is higher, and in order to reduce the temperature difference (target 2) before and after conversion, a higher methanol water vapor supply flow rate is required. As the overlap increases and the angle of the booster heat patch decreases, the space through which the reactant gas flows decreases, and at high methanol steam supply flow rates, the flow energy loss in the reformer increases, requiring moderate supply flow rates to reduce the flow energy loss (target 3). Under the trade-off of the three optimization targets, the genetic algorithm GA is used for global optimization to obtain a proper design variable optimization result.
In this embodiment, after step S107, the method further includes calculating, for a given performance characterization index corresponding to an optimal value of the design parameter, an increase rate of each performance characterization index before and after the design parameter optimization as an evaluation result of the design parameter optimization by combining the original performance characterization index of the reformer, and defining the increase rate:
In the above, beta ex To optimize the front parameters beta re For the optimized parameters, beta is the methanol conversion rate X CH4O Electric hydrogen energy conversion ratio lambda, hydrogen yield lambda H2 Under the same operation condition, compared with the reformer without a supercharging structure, the electric hydrogen energy conversion level is improved remarkably after the methanol conversion rate is optimized, as shown in fig. 10, which shows that the heat exchange effect increased by the optimized structure effectively counteracts the descending trend caused by the increase of the supply flow rate. At the same time, the electric hydrogen energy conversion ratio is increased by more than 30 percent and the hydrogen yield is increased by more than 90 percent, and compared with a reformer with a non-supercharged heating body structure under the same working condition, the electric hydrogen energy conversion ratio is increased by more than 60 percent (lambda) rise0 )。
The temperature, hydrogen concentration and pressure distribution in the reformer after optimization are shown in fig. 11, compared with the temperature of the catalytic bed of the reformer before optimization (as shown in fig. 7), the temperature of the catalytic bed of the reformer is distributed more uniformly in the radial direction, the global temperature difference is smaller, the temperature maximum and the position thereof are closer to the probe position, the temperature maximum and the position thereof are better to the probe position, the accurate feedback control (such as a thermocouple) of the temperature in actual operation is facilitated, the cloud image profile of the radial distribution of the hydrogen concentration is more fuzzy, the cloud image profile in fig. 11 is more (b), the reaction rate is more uniform in the radial direction, the circulation space of the reaction gas in the reformer is reduced under the optimization of the coincidence ratio, the space of the two meshing positions is reduced under the optimization of the pressurizing heating sheet angle, the pressure drop in the reformer is larger, the flow energy loss is still at a lower level due to the smaller size of the reformer monomer in fig. 11.
Coil power is one of the main heat sources for reaction in the reformer, and after optimization, the coil power and estimated electric power of hydrogen after conversion are also increased significantly due to the increase of the methanol steam supply flow rate, so as to comprehensively evaluate the energy capacity of the reformer system, and in this embodiment, the net power P is defined net The method comprises the following steps: p (P) net ＝P H2 -P coil -P Pa . Experiments show that the coil power before optimization is 194W and the coil power after optimization is raised to 277W. The estimated electric power of the hydrogen before optimization is 385W, and the estimated electric power is 736W after optimization; net power P before optimization net 191W, and the optimized lifting is 460W. It follows that the net power P after optimization net The power supply requirement of about 460W can be met by more than 1 time. Therefore, as the overlap ratio of the pressurizing heating sheets increases and the angle is reduced to form an acute angle, the pressurizing heating sheets are arranged towards the inlet end, the heating and heat exchange effects in the reformer are better, more hydrogen is produced, the electric hydrogen energy conversion level is improved, but the temperature difference and pressure drop between the front and back of the reaction gas conversion can also be obviously increased, the temperature distribution and the hydrogen concentration distribution of the catalytic bed of the reformer after optimization are more uniform, the pressure drop is increased, and under the cooperative optimization of the pressurizing structure and the operation parameters of the reformer, compared with the reformer before optimization (ζ=0, α=90°, V in =0.8 m/s), methanol conversion increased by 22.79%, electro-hydrogen conversion ratio increased by 34.2%, net power increased by more than 1 time, A hydrogen yield of about 736W and a net power of about 460W can be achieved, and the electric-to-hydrogen conversion ratio is increased by 64.17% compared to a non-booster heat-generating body structure.
In summary, the embodiment designs a novel reformer based on the tubular structure and the induction heating method, and combines the fluid pressure drop characteristics and the control concept during the methanol vapor supply reaction, and adopts a combination mode of simulation and experiment, so as to analyze the influence rule of the pressurizing structure and the operation parameters of the reformer, and complete the cooperative optimization of the system through the performance prediction model and the genetic algorithm, thereby improving the reforming hydrogen production reaction environment and improving the efficiency, and the main conclusion is as follows: 1) Heating experiments aiming at two heating element reformers show that compared with a non-supercharged heating element, the inside of the reformer adopts a supercharged heating element structure, so that the heat supplementing effect of gas can be effectively improved, the fluid pressure drop of methanol vapor can be effectively controlled, the heat exchanging area of the reformer can be increased through reasonable structural parameter optimization, a reasonable catalytic reaction temperature gradient environment and reaction time are provided for reactants, and the hydrogen production performance of the reformer is improved. 2) The internal pressurizing heating body of the reformer is in a relatively high-temperature state, the contact ratio of the pressurizing heating piece is increased, the angle of the pressurizing heating piece is arranged towards the inlet end, the angle is gradually reduced, the electric-hydrogen energy conversion ratio, the methanol conversion rate and the hydrogen yield are obviously increased, and meanwhile, the temperature difference before and after the conversion of the reaction gas and the flow energy loss of the reaction gas are increased. 3) Setting the maximum electric-hydrogen energy conversion ratio, and the minimum temperature difference before and after conversion and the minimum flow energy loss as comprehensive optimization targets of the service performance of the system, and adopting a neural network and a genetic algorithm GA to perform optimization to obtain the pressurizing heating sheet with the contact ratio of 0.45, the angle of 75 degrees, the feeding flow velocity of methanol water vapor towards the inlet end of 1.1m/s. The net power of the reformer after optimization can reach 460W, the conversion rate of methanol is improved by 22.79 percent compared with the conversion rate of methanol before optimization, and the conversion rate of electric hydrogen energy is improved by 64.17 percent compared with a device without a supercharged heating body structure.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to the present invention may occur to one skilled in the art without departing from the principles of the present invention and are intended to be within the scope of the present invention.
Claims (10)
1. The utility model provides a reformer, includes shell (1) and locates outside induction coil (2) of shell (1), the inside catalytic bed (4) that are equipped with both sides and pass through porous baffle (3) partition wall of shell (1), be equipped with heat-generating body (5) in catalytic bed (4), its characterized in that, be equipped with on the outer wall of heat-generating body (5) outward bulge and arrange pressure boost piece (51) that generates heat, just be filled with the catalyst in catalytic bed (4) in the space region between the outer wall of heat-generating body (5) and pressure boost piece (51) and shell (1) inner wall.
2. Reformer according to claim 1, characterized in that the said pressurizing heat generating fins (51) are of annular structure and are uniformly sleeved on the outer wall of the heat generating body (5), and the number of pressurizing heat generating fins (51) provided on the outer wall of the heat generating body (5) is plural.
3. Reformer according to claim 2, characterized in that the casing (1) is provided with a plurality of evenly distributed guide vanes (11) on the inner wall at the catalytic bed (4), the guide vanes (11) are of annular structure and are embedded on the inner wall of the casing (1), and the plurality of guide vanes (11) and the plurality of supercharging heating plates (51) are arranged in a staggered manner.
4. A reformer according to claim 3, wherein the booster heat generating sheet (51) and the heat generating body (5) are of a unitary structure made of ferromagnetic material.
5. A method for optimizing design parameters of a reformer according to any one of claims 1 to 4, comprising:
s101, determining design parameters of a reformer;
s102, building a service performance simulation model for obtaining service performance of the reformer in a simulation mode based on design parameters of the reformer and working condition parameters of the reformer during hydrogen production in service;
s103, manufacturing a sample of the reformer based on design parameters of the reformer, respectively obtaining experimental values of service performance indexes of the sample of the reformer under the same design parameters and simulation values of the service performance indexes of the service performance simulation model through orthogonal experiments of the design parameters, and judging that the service performance simulation model passes verification and jumps to the step S104 if the difference between the experimental values of the service performance indexes and the simulation values meets the requirements; otherwise, step S102 is skipped to readjust the service performance simulation model;
S104, taking the service performance simulation model as a basis, taking different combinations of design parameters as input to perform service performance simulation experiments to obtain simulation values of service performance indexes of the reformer under the different combinations of design parameters, and constructing the different combinations of design parameters and the simulation values of the corresponding service performance indexes to obtain a design and performance parameter data set;
s105, establishing a reformer performance prediction model for realizing the mapping relation between design parameters of different combinations and evaluation values of corresponding service performance indexes by utilizing the design and performance parameter data set; taking the design parameters of different combinations as input of a reformer performance prediction model based on the design and performance parameter data set to obtain a service performance evaluation value, taking the same design parameters as a service performance simulation model to obtain a simulation value of a service performance index, and training and optimizing the reformer performance prediction model by utilizing the simulation value of the service performance index and the difference value between the service performance evaluation values until the simulation value of the service performance index and the difference value between the service performance evaluation values are smaller than a set value, thereby obtaining a trained reformer performance prediction model;
S106, determining the weight of each service performance index element in the service performance index, and constructing a service performance optimization objective function formed by weighted summation of each service performance index element;
and S107, optimizing the service performance optimization objective function by adopting an optimization algorithm to obtain an optimal value of the design parameter.
6. The reformer according to claim 5Wherein, when determining the design parameters of the reformer in step S101, the determined design parameters of the reformer include an inlet flow velocity V in The pressurizing heating piece overlap ratio zeta refers to the ratio of the length of the pressurizing heating piece (51) and the length of the guide piece (11) overlapped in the radial direction to the annular width of the catalytic bed (4), and the pressurizing heating piece angle alpha refers to the included angle between the pressurizing heating piece (51) and the heating piece (5) towards the inlet side direction.
7. The method for optimizing design parameters of a reformer according to claim 6, wherein the calculation function expression of the contact ratio ζ of the pressurizing heat generating fin is:
in the above, h fin Represents the height of the pressurizing heating sheet (51), D in Represents the internal diameter, d, of the catalytic bed (4) heat The inner diameter of the heating element (5) is shown.
8. The method for optimizing design parameters of a reformer according to claim 6, wherein each service performance index element in the service performance index in step S106 includes an electro-hydrogen energy conversion ratio λ, a temperature difference T before and after conversion dif Flow energy loss P pa Wherein the temperature difference T between before and after conversion dif Refers to the temperature difference between the input end and the output end of the reformer, the electro-hydrogen energy conversion ratio lambda and the flow energy loss P pa The expression of the calculation function of (c) is:
in the above, P H2 For the estimated power of the hydrogen produced, P coil The electric power provided for the induction coil (2), ΔP is the reformer inlet-outlet pressure difference, V in For inlet flow rateS is the inlet and outlet area of the reformer.
9. The method according to claim 5, further comprising, after step S107, calculating, for a given performance characterization index corresponding to an optimal value of the design parameter, an increase rate of each performance characterization index before and after the design parameter optimization as an evaluation result of the design parameter optimization, in combination with an original performance characterization index of the reformer.
10. The method of optimizing design parameters of a reformer according to claim 9, wherein the given performance characteristic comprises a methanol conversion X CH4O Electric hydrogen energy conversion ratio lambda, hydrogen yield lambda H2 ；
Methanol conversion X CH4O The expression of the calculation function of (c) is:
X CH4O ＝(n in -out)/ in ，
in the above, n in And n out The molar amount of methanol input to and output from the reformer, respectively;
the electric hydrogen energy conversion ratio lambda is calculated by the following functional expression:
in the above, P H2 For the estimated power of the hydrogen produced, P coil The induction coil (2) is supplied with electric power.
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