Ammonia decomposition reactor simulation device and method therefor

Abstract

A simulation device capable of effectively deriving heat transfer efficiency occurring in an ammonia decomposition reactor, and a method therefor can be provided, the simulation device comprising: a data input unit for receiving simulation basic data including structural data of the ammonia decomposition reactor including a combustion furnace, a burner and a reaction tube, physical property data of working fluids in the ammonia decomposition reactor, and time data related to heat transfer time in the ammonia decomposition reactor; a model configuration unit for constructing a computational fluid dynamics (CFD) model on the basis of the simulation basic data; and a simulation unit using the CFD model to simulate heat transfer that occurs among the combustion furnace, the burner and the reaction tube.

Description

Ammonia decomposition reactor simulation device and method

[0001] The present invention relates to an ammonia decomposition reactor simulation device and a method thereof.

[0002] In modern engineering, three-dimensional CFD (Computational Fluid Dynamics) analysis is required for the mechanical design of thermochemical decomposition reactors. However, since the ammonia decomposition reaction is not a traditional decomposition reactor like SMR (Steam Methane Reforming), there is no data available for design. An ammonia decomposition reactor is broadly divided into a combustion chamber where combustion reactions take place and reaction tubes where ammonia decomposition reactions take place.

[0003] Since the ammonia decomposition reaction is a strongly endothermic reaction, the efficient transfer of combustion heat is critical to the design. However, as it is difficult to experimentally measure such heat transfer, there is a need to develop technologies capable of predicting or verifying the heat transfer efficiency of ammonia decomposition reactors.

[0004] The problem that the technical concept of the present invention aims to solve is to provide a simulation device and a method capable of effectively deriving the heat transfer efficiency generated within an ammonia decomposition reactor.

[0005] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall details of the specification.

[0006] According to exemplary embodiments for solving the problem of the present invention, a simulation device is provided. The simulation device may include: a data input unit configured to receive simulation basic data including structural data of an ammonia decomposition reactor comprising a combustion furnace, a burner, and a reaction tube, physical property data of working fluids within the ammonia decomposition reactor, and time data related to heat transfer time within the ammonia decomposition reactor; a model configuration unit configured to construct a Computational Fluid Dynamics (CFD) model based on the simulation basic data; and a simulation unit configured to simulate heat transfer phenomena occurring between the combustion furnace, the burner, and the reaction tube using the CFD model.

[0007] The above structural data may include first structural data associated with the combustion furnace and burner, second structural data associated with the outside of the reaction tube, and third structural data associated with the inside of the reaction tube.

[0008] The above model configuration unit includes a calculation area setting unit that generates a first grid, a second grid, and a third grid corresponding to each of the first structural data, the second structural data, and the third structural data, and the simulation unit may be configured to calculate the amount of heat transfer of working fluids for the first grid, the second grid, and the third grid based on the time data.

[0009] The above model configuration unit includes a time step setting unit configured to set a first time step corresponding to heat transfer in the combustion furnace and burner, a second time step corresponding to heat transfer in the outer wall of the reaction tube, and a third time step corresponding to heat transfer inside the reaction tube based on the above time data, and the time step setting unit matches the first to third time steps to the first to third grids, respectively, and the simulation unit can perform calculations over the time steps matched to the first to third grids.

[0010] The longest time step can be selected by comparing the first time step, the second time step, and the third time step, and the calculation for the remaining time steps can be repeated until the calculation for the longest time step is completed.

[0011] The above first to third time steps may have different intervals.

[0012] The above model configuration unit includes a governing equation setting unit that sets governing equations based on the above simulation basic data, and the above redefinition setting unit sets a first governing equation, a second governing equation, a third governing equation, and a fourth governing equation as governing equations of the CFD model, wherein the first governing equation is an equation regarding mass transfer within the ammonia decomposition reactor, the second governing equation is an equation regarding the flow of the above working fluids, the third governing equation is an equation regarding chemical reactions between the above working fluids, and the fourth governing equation may be an equation regarding heat transfer within the ammonia decomposition reactor.

[0013] The above governing equation setting unit can further set a fifth governing equation for the pressure drop inside the reaction tube.

[0014] The above calculation area setting unit can increase the number of calculation cells included in each grid as the number of types of components participating in the chemical reaction increases in each grid.

[0015] The number of calculation cells in the first grid may be greater than the number of calculation cells in the second grid.

[0016] The number of calculation cells in the third grid may be greater than the number of calculation cells in the second grid.

[0017] The number of calculation cells in the third grid above may be less than the number of calculation cells in the first grid above.

[0018] The above model configuration unit may include: a computational domain setting unit that generates a computational grid based on the structural data; a time step setting unit that sets a plurality of time steps based on the time data; and a governing equation setting unit that sets a governing equation based on the physical property data.

[0019] According to other exemplary embodiments of the present invention, a simulation method is provided. The simulation method, in a method for simulating an ammonia decomposition reaction performed on a computing device, may include the steps of: receiving simulation base data including structural data of an ammonia decomposition reactor comprising a combustion furnace, a burner, and a reaction tube, physical property data of working fluids within the ammonia decomposition reactor, and time data related to heat transfer time within the ammonia decomposition reactor; constructing a Computational Fluid Dynamics (CFD) model based on the simulation base data; and simulating a heat transfer phenomenon occurring between the combustion furnace, the burner, and the reaction tube using the CFD model.

[0020] According to exemplary embodiments of the present invention, a simulation device and a method capable of effectively deriving the heat transfer efficiency generated within an ammonia decomposition reactor can be provided.

[0021] The various and beneficial advantages and effects of the present invention are not limited to those described above and will be more easily understood in the process of explaining specific embodiments of the present invention.

[0022] Figure 1 is a diagram illustrating an ammonia decomposition reactor.

[0023] FIG. 2 is a drawing for illustrating a simulation device according to exemplary embodiments.

[0024] Figure 3 is a diagram illustrating the generation of a computational grid of reaction tubes.

[0025] Figure 4 is a diagram illustrating the calculation of heat transfer amount based on time data of the simulation unit.

[0026] FIG. 5 is a flowchart illustrating a simulation method according to exemplary embodiments.

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0028] In the following descriptions with reference to the drawings, identical or corresponding components are assigned the same reference numerals, and redundant descriptions thereof will be omitted.

[0029] In the following embodiments, the terms first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0030] In the following embodiments, the singular expression includes the plural expression unless the context clearly indicates otherwise.

[0031] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0032] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0033] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0034] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0035] The present invention will be described in detail below through each embodiment. It should be noted that each embodiment described in this specification is not limited to a single embodiment but may also be combined with other embodiments. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0036] The present invention will be described in detail below through examples. However, it should be noted that the following examples are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0037] Figure 1 is a drawing for explaining an ammonia decomposition reactor (100).

[0038] FIG. 2 is a drawing for explaining a simulation device (200) according to exemplary embodiments.

[0039] Referring to FIGS. 1 and 2, the ammonia decomposition reactor (100) includes a combustion furnace (110), a burner (120), and a reaction tube (130).

[0040] According to exemplary embodiments, the combustion furnace (110) can receive a flame generated from a reaction tube (130) and a burner (120) in an internal space (S) and heat the reaction tube (130). The reaction tube (130) is installed through the combustion furnace (110) and is separated from the internal space (S) by the outer wall (W) of the reaction tube (130). The internal space (S) of the combustion furnace (110) is heated by the flame provided from the burner (120), and the interior (R) of the reaction tube is heated by the outer wall (W) of the reaction tube. In this way, the ammonia decomposition reactor (100) can transfer thermal energy generated from the burner (120) to the interior (R) of the reaction tube where the ammonia decomposition reaction takes place through the combustion furnace (110) and the outer wall (W) of the reaction tube. Therefore, in order to verify the performance of the ammonia decomposition reactor (100), it is necessary to develop a technology capable of predicting or verifying the heat transfer efficiency occurring inside the ammonia decomposition reactor (100).

[0041] The simulation device (200) may be a computing device capable of simulating the ammonia decomposition reaction and heat transfer phenomena occurring within an ammonia decomposition reactor. At this time, the ammonia decomposition reaction may be performed through the following reaction equation 1.

[0042] [Reaction Equation 1]

[0043] 2NH3→ N2+ 3H2

[0044] The simulation device (200) may be implemented with one or more computing devices. More specifically, the simulation device (200) may be implemented with a single computing device or with multiple computing devices. As one example, a first function of the simulation device (200) may be implemented in a first computing device, and a second function may be implemented in a second computing device. As another example, a specific function of the simulation device (200) may be implemented in multiple computing devices.

[0045] The above computing device may be, for example, a notebook, desktop, laptop, etc., but is not necessarily limited thereto and may include all types of devices equipped with computing functions. For an example of a computing device, refer to FIG. 2.

[0046] The simulation device (200) may include a data input unit (210), a model configuration unit (220), a simulation unit (230), a visualization unit (240), and a DB (250). However, this is merely an exemplary embodiment for achieving the purpose of the present disclosure, and it is understood that some components may be added or omitted as needed. Furthermore, it should be noted that each component (e.g., 110) of the simulation device (200) illustrated in FIG. 2 represents functionally distinct functional elements, and that multiple components (e.g., 110) may be implemented in a form that integrates with each other in an actual physical environment. Of course, in an actual physical environment, each of the above components (e.g., 210) may be implemented in a form that is subdivided into multiple functional elements. Below, each component of the simulation device (200) will be described.

[0047] Each component of FIG. 2 (e.g., 210) may represent software or hardware such as a Field Programmable Gate Array (FPGA) or an Application-Specific Integrated Circuit (ASIC). However, the components are not limited to software or hardware and may be configured to reside in an addressable storage medium or configured to execute one or more processors. Functions provided within the components may be implemented by more subdivided components, or multiple components may be combined to form a single component that performs a specific function.

[0048] The data input unit (210) is configured to receive simulation basic data including structural data of an ammonia decomposition reactor (100) comprising a combustion furnace (110), a burner (120), and a reaction tube (130), physical property data of working fluids within the ammonia decomposition reactor (100), and time data related to heat transfer time within the ammonia decomposition reactor (100). The simulation basic data may further include initial condition and / or boundary condition data of a CFD model. Initial conditions and / or boundary conditions are conditions set to accurately perform the simulation and can be used to solve governing equations through numerical analysis techniques. As an example, the initial conditions may be conditions related to the variables of the governing equations described below.

[0049] The method by which the data input unit (210) receives simulation basic data can be any method. For example, the data input unit (210) may receive simulation basic data through a web interface (e.g., web GUI). Alternatively, the data input unit (210) may receive simulation basic data from a file stored in a local storage. Of course, the data input unit (210) may also receive simulation basic data in the form of a file through a web interface.

[0050] Simulation basic data can be stored in DB (250). To this end, the data input unit (210) can communicate with DB (250) via a wired or wireless data network. The data input unit (210) can transmit simulation basic data to DB (250). The data network may be unidirectional or bidirectional. The data network may be implemented by a physical channel, WiFi, Bluetooth and / or a public network and / or specialized network using other frequency bands. However, the present invention is not limited thereto, and the data input unit (210) itself may store simulation basic data.

[0051] Structural data may include various data that can represent or define the structure of the ammonia decomposition reactor (100). According to exemplary embodiments, structural data may include modeling data for the ammonia decomposition reactor (100) (e.g., 2D modeling data, 3D modeling data, etc.), solid regions that determine the shape of each member (e.g., 110, 120, etc.) within the ammonia decomposition reactor (100), fluid regions where working fluids flow, and flame regions where a flame is formed. However, the present invention is not limited thereto and may further include various data regarding the ammonia decomposition reactor (100) and the ammonia decomposition reaction occurring within it.

[0052] According to exemplary embodiments, the structural data may include a first structural data associated with the combustion furnace (110) and the burner (120), a second structural data associated with the outer wall (W) of the reaction tube (130), and a third structural data associated with the inner (R) of the reaction tube (130). As described above, the combustion furnace (110) is heated directly by the burner (120), and the inner (R) of the reaction tube (130) is heated indirectly as the outer wall (W) is heated. That is, within the ammonia decomposition reactor (100), the thermal energy generated in the burner (120) is transferred in the order of the combustion furnace (110), the outer wall (W) and the inner (R) of the reaction tube (130), thereby allowing the ammonia decomposition reaction to be performed. Accordingly, according to exemplary embodiments, by distinguishing and grouping structural data regarding each member of the heat transfer path, heat transfer occurring inside the ammonia decomposition reactor (100) can be simulated more accurately.

[0053] The first structural data may include modeling data for the combustion furnace (110) and the burner (120) (e.g., 2D modeling data, 3D modeling data, etc.), a solid region that determines the shape of the combustion furnace (110) and the burner (120) (e.g., an outer wall, etc.), a fluid region where working fluids flow (e.g., an internal space, a working fluid supply nozzle, etc.), and data regarding a flame region where a flame is formed.

[0054] The second structural data may include modeling data for the outer wall (W) of the reaction tube (130) (e.g., 2D modeling data, 3D modeling data, etc.).

[0055] The third structural data may include modeling data for the interior (R) of the reaction tube (130) (e.g., 2D modeling data, 3D modeling data, etc.), fluid regions where working fluids flow (e.g., working fluid supply nozzles, etc.), and data regarding the catalyst placed in the interior (R) of the reaction tube (130) (e.g., porosity of the catalyst fixed layer, etc.).

[0056] The working fluid of the ammonia decomposition reactor (100) may include raw materials and oxygen gas for combustion of the burner, combustion flue gas, ammonia gas which is the raw material for the ammonia decomposition reaction, reaction gas containing nitrogen, hydrogen, and undecomposed ammonia as the product of the ammonia decomposition reaction, and atmosphere gas or purge gas within the combustion furnace (110) and reaction tube (130). That is, it refers to any fluid that can be verified as actually flowing within the ammonia decomposition reactor (100) or assumed to flow within the ammonia decomposition reactor (100) for simulation purposes. In this case, as an example, the raw material may be a fossil fuel. As an example, the raw material may be a hydrogen purification process tail gas derived from the hydrogen purification process after ammonia decomposition. The type of raw material is not particularly limited as long as it can provide the thermal energy required for the ammonia decomposition reaction through the combustion reaction and its composition is known. Physical property data may include data regarding the type of working fluid participating in the chemical reaction, as well as the flow rates, temperatures, specific heat, density, pressure, thermal conductivity, etc. of the working fluids, but is not limited to the listed properties.

[0057] The material property data may further include data regarding the material properties (material composition, thermal conductivity, etc.) of the outer wall (W) material of the reaction tube (130).

[0058] The time data may include data regarding the time taken to complete mutual heat transfer between each member (110, 120, 130) of the ammonia decomposition reactor (100) and the time taken to complete heat transfer due to the chemical reaction in the burner (120) and the reaction tube (130).

[0059] Time data can be set and input based on information regarding chemical reactions in the burner (120) and reaction tube (130), temperature profiles of each component (110, 120, 130), and material information constituting each component (110, 120, 130) of the ammonia decomposition reactor (100). Information regarding chemical reactions in the burner (120) and reaction tube (130) may include the enthalpy, reaction rate, temperature, catalytic activity, etc. of each chemical reaction.

[0060] In the actual environment, heat transfer (exchange) between each component (110, 120, 130) within the ammonia decomposition reactor (100) occurs in real time. However, the events in which heat transfer occurs for each component (110, 120, 130) (e.g., flame propagation in the internal space (S) of the combustion chamber, heat conduction on the wall (W) of the reaction tube (130), and catalytic reaction inside (R) of the reaction tube (130)) differ from one another. Consequently, the number of times heat transfer occurs may also differ for each component. For example, since the combustion reaction in the burner (120) is very fast, heat transfer proceeds very quickly. Also, since the catalytic reaction inside (R) of the reaction tube (130) also proceeds quickly, heat absorption (transfer) proceeds very quickly. In contrast, heat transfer on the outer wall (W) of the reaction tube (130) proceeds relatively slowly compared to the heat transfer described above. That is, assuming that heat transfer at the outer wall (W) of the reaction tube (130) is completed once, it can be concluded that heat transfer at the burner (120) and the inside (R) of the reaction tube (130) is completed many times. Therefore, if heat transfer at each component (110, 120, 130) is simulated uniformly under the same conditions, it may be difficult to accurately predict or verify the performance of the ammonia decomposition reactor (100). According to exemplary embodiments, the performance of the ammonia decomposition reactor (100) can be predicted more accurately by additionally considering time data related to the heat transfer time.

[0061] In addition, the simulation basic data may further include simulation accuracy, the form of the calculation grid (e.g., 2D, 3D, aligned, unaligned), the density of the calculation grid, the number of calculation cells, the type of governing equation, initial conditions, boundary conditions, regions of interest, etc. However, it is not limited thereto.

[0062] The model configuration unit (220) may be configured to construct a CFD (Computational Fluid Dynamics) model based on input simulation basic data. A CFD model refers to a model for analyzing fluid phenomena; as those skilled in the relevant technical field will clearly understand what a CFD model is, a detailed explanation thereof will be omitted.

[0063] According to exemplary embodiments, the model configuration unit (220) may be configured to include a calculation domain setting unit (221), a time step setting unit (222), and a governing equation setting unit (223).

[0064] The computational area setting unit (221) can produce a computational grid based on structural data. The computational grid refers to a computational area formed in the form of a grid, and each computational cell constituting the computational grid can be the minimum unit of simulation calculation. Therefore, as the number of computational cells increases (i.e., as the computational grid becomes denser), the accuracy of the simulation increases, and the computing cost required for the simulation can also increase. Conversely, as the number of computational cells decreases (i.e., as the computational grid becomes less dense), the accuracy of the simulation decreases and the computing cost can also decrease. The computational grid can take the form of an aligned grid or an unaligned grid, and it can be a two-dimensional grid or a three-dimensional grid. As those skilled in the art will clearly understand the computational grid of the CFD model, further detailed explanation regarding this will be omitted.

[0065] Specifically, the computational area setting unit (221) can generate a computational grid corresponding to the physical structure of a component of the target ammonia decomposition reactor (100) based on structural data of a component (110, 120, 130) of the target ammonia decomposition reactor (100). According to exemplary embodiments, the computational area setting unit (221) can generate a first grid, a second grid, and a third grid corresponding to each of the first structural data, the second structural data, and the third structural data. The first grid is based on the first structural data. The second grid is based on the second structural data. The third grid is based on the third structural data. Additionally, the computational area setting unit (221) may generate the computational grid based further on simulation basic data regarding the computational grid (e.g., the shape of the computational grid, the number of computational cells, density, etc.).

[0066] Figure 3 is a diagram illustrating the generation of a computational grid of a reaction tube (130).

[0067] Referring to FIG. 3, the reaction tube (130) includes a cylindrical outer wall (W) and an interior (R) defined by the outer wall (W). The model component (220) can generate a second computational grid (G1) and a third computational grid (G2) based on second structural data, which is structural data regarding the outer wall (W) of the reaction tube (130), and third structural data related to the interior (R) of the reaction tube (130).

[0068] This will be explained again with reference to Figs. 1 and 2.

[0069] According to exemplary embodiments, the computation area setting unit (221) may adjust the number of computation cells and / or the density of the computation grid based on the computing performance and / or available computing resources of the simulation device (200). For example, if the available computing resources (or computing performance) are above a reference value, the computation area setting unit (221) may increase the number of computation cells, such as by creating a 3-dimensional computation grid or a 2-dimensional computation grid with high density. Conversely, if the number is lower, the computation area setting unit (221) may decrease the number of computation cells, such as by creating a 2-dimensional computation grid or a 3-dimensional computation grid with low density. In such cases, the simulation can be performed efficiently by taking into account the computing performance and / or available computing resources of the simulation device (200).

[0070] According to exemplary embodiments, the computational area setting unit (221) can increase the number of computational cells in a computational grid that is highly associated with heat transfer. The computational area setting unit (221) can increase the number of computational cells included in each grid as the number of types of components participating in the chemical reaction increases in each grid.

[0071] The first grid is a computational grid corresponding to the combustion furnace (110) and the burner (120), where a high level of heat transfer occurs. In particular, since a combustion reaction of fuel occurs in the burner (120), at least the fuel component and the oxidizer component can participate in the chemical reaction in the first grid.

[0072] The second grid is a computational grid corresponding to the outer wall (W) of the reaction tube (130) and can substantially consider only heat transfer by conduction. Therefore, the second grid may not substantially include the types of components participating in the chemical reaction.

[0073] The third grid is a computational grid corresponding to the interior (R) of the reaction tube (130). Since the ammonia decomposition reaction occurs in the interior (R) of the reaction tube (130), at least ammonia can participate in the chemical reaction in the third grid.

[0074] Considering the above, according to exemplary embodiments, the number of calculation cells in the first grid may be greater than the number of calculation cells in the second grid. The number of calculation cells in the third grid may be greater than the number of calculation cells in the second grid. The number of calculation cells in the third grid may be less than the number of calculation cells in the first grid. The number of calculation cells in the first grid may be the greatest. The number of calculation cells in the second grid may be the least. However, the present invention is not limited thereto, and assuming an additional chemical reaction (such as nitration of the catalyst) inside the reaction tube (130) (R), the number of calculation cells in the third grid may be higher than the number of calculation cells in the first grid.

[0075] The time step setting unit (222) can set multiple time steps based on time data. More specifically, the time step setting unit (222) may be configured to set a first time step corresponding to heat transfer in the combustion furnace (110) and burner (120), a second time step corresponding to heat transfer in the outer wall (W) of the reaction tube (130), and a third time step corresponding to heat transfer inside (R) of the reaction tube (130).

[0076] The time step setting unit (222) can match the set first to third time steps to the first to third grids, respectively. More specifically, the first time step can be matched to the first grid. The second time step can be matched to the second grid. The third time step can be matched to the third grid.

[0077] The first time step can be set by taking into account the combustion reaction time in the burner (120). The combustion reaction time can be set by referring to a reaction rate constant, but is not necessarily limited thereto.

[0078] The second time step may be set by referring to the thermal conductivity of the material constituting the outer wall (W) of the reaction tube (130) and the thickness of the outer wall (W), but is not necessarily limited thereto.

[0079] The third time step can be set by taking into account the ammonia decomposition reaction time inside (R) the reaction tube (130). The ammonia decomposition reaction time can be set by taking into account the reaction rate constant, temperature, and catalytic activity, but is not necessarily limited thereto.

[0080] According to exemplary embodiments, the first to third time steps may have different intervals. The first time step may be smaller than the second time step. The first time step may be smaller than the third time step. The third time step may be smaller than the second time step.

[0081] The governing equation setting unit (223) can set governing equations based on simulation basic data. The governing equations refer to equations that define fluid phenomena or describe the relationship with various variables (e.g., temperature, pressure, etc.) that affect fluid phenomena; however, since those skilled in the relevant technical field are likely already familiar with the concept of governing equations, an explanation regarding this will be omitted. The governing equation setting unit (223) can set the first governing equation, the second governing equation, the third governing equation, and the fourth governing equation as the governing equations of the CFD model. The governing equation setting unit (223) can match the set governing equations with the computational grids by considering heat transfer in each computational grid.

[0082] The first governing equation may be an equation regarding mass transfer within the ammonia decomposition reactor (100). The first governing equation may be an equation derived from the law of conservation of mass and may be expressed as Equation 1 below as an example.

[0083] [Mathematical Formula 1]

[0084]

[0085] In the above mathematical formula 1, ρ is the density of the working fluid (kg / m³). 3) and v is the velocity (m / s) of the working fluid, and ▽(ρv) represents the mass flux of the working fluid. The working fluid may be a working fluid involved in a combustion reaction. The working fluid may be a working fluid involved in an ammonia decomposition reaction. The density, velocity, etc. for each working fluid may be provided from the data input unit (210). In the following description, for the clarity of the present disclosure, explanations of parameters (variables, constants, etc.) that overlap with the mathematical formulas described above will be omitted, and if a parameter with the same symbol is used with a different meaning, it will be newly explained in the relevant formula. In addition, some of the parameters of the mathematical formulas mentioned in the present disclosure may be calculated during the simulation process, and experimentally obtained values ​​may be substituted into others.

[0086] The second governing equation may be an equation regarding the flow of working fluids. The second governing equation may be an equation derived from the law of conservation of momentum and may be a formula representing the relationship between fluid velocity and pressure, etc., and as an example, it may be expressed as the following mathematical formula 2.

[0087] [Mathematical Formula 2]

[0088]

[0089] In the above mathematical formula 2, P is pressure (N / m 3 It means ) and Y k represents the mass fraction of species k, and f k represents the external force acting on species k or the coefficient of force (N) acting in a chemical reaction, and V k k represents the velocity (m / s) of the k species. Here, k refers to individual substances in the working fluid (liquid or gaseous substances involved in each chemical reaction, such as ammonia, combustion agents, etc.).

[0090] The third governing equation is an equation relating to chemical reactions between working fluids, and more specifically, an equation that can explain how the mass fraction of each chemical species in the working fluid changes over time and space. As an example, the third governing equation can be expressed as Equation 3 below.

[0091] [Mathematical Formula 3]

[0092]

[0093] In the above mathematical formula 3, ω k represents the production rate or extinction rate resulting from the chemical reaction of k types.

[0094] The fourth governing equation is an equation regarding heat transfer within an ammonia decomposition reactor and can explain temperature changes, pressure, rate, and the generation and loss of energy due to chemical reactions in the ammonia decomposition reactor (100). The fourth governing equation can be expressed as Equation 4 or Equation 5 below, as an example.

[0095] [Mathematical Formula 4]

[0096]

[0097] [Mathematical Formula 5]

[0098]

[0099] In the above mathematical formulas 4 and 5, c v represents specific heat (J / (kg·K)), T represents temperature (K), and e k represents the energy of type k (J / kg), and c v,k k represents the specific heat of the species, and Q represents the heat energy (K / s) generated by the combustion reaction.

[0100] Meanwhile, the governing equation setting unit (223) may further set a fifth governing equation for the pressure drop inside (R) of the reaction tube (130). The fifth governing equation can be calculated in conjunction with the second governing equation. As an example, the fifth governing equation can be expressed as the following mathematical equations 6 to 8.

[0101] [Mathematical Formula 6]

[0102]

[0103] [Mathematical Formula 7]

[0104]

[0105] [Mathematical Formula 8]

[0106]

[0107] In the above mathematical formulas 6 to 8, u0(r) represents the fluid velocity profile (m / s), and represents the viscous characteristics (Pa·s) of a fluid within a porous medium (e.g., a catalyst), and represents porosity, that is, the ratio of empty spaces formed in a porous medium, and represents the viscosity of the fluid (Pa·s), and ρ f represents the density of the fluid, and d p represents the average diameter (m) of the particles constituting the porous medium. Additionally, f1 is based on Darcy's law and represents the linear pressure loss inside (R) of the reaction tube (130). f2 is based on the Forchheimer equation and represents the non-linear pressure loss inside (R) of the reaction tube (130). Meanwhile, the third term on the right side of Equation 6 represents the effect of the velocity gradient on the pressure loss due to the viscous effect of the fluid, which can explain the diffusion and viscous force within the porous medium.

[0108] According to exemplary embodiments, the first to fourth governing equations may be matched to the first grid. The fourth governing equation may be matched to the second grid. More specifically, the fourth governing equation according to Equation 5 may be matched to the second grid. The first to fifth governing equations may be matched to the third grid.

[0109] The simulation unit (230) may be configured to simulate heat transfer phenomena occurring between the combustion furnace (110), the burner (120), and the reaction tube (130) using a CFD model. More specifically, the simulation unit (230) can convert the governing equations set through numerical analysis techniques (e.g., FDM, FEM, FVM, etc.) into algebraic equations and calculate the values ​​of simulation variables associated with the ammonia decomposition reaction by solving the algebraic equations according to initial conditions or boundary conditions. The above heat transfer phenomenon may refer to one or more of the following phenomena: a combustion reaction occurring in the burner (120), a heating reaction caused by a flame provided inside the combustion furnace (110), a phenomenon in which the outer wall (W) of the reaction tube (130) is heated by the atmospheric temperature of the space (S) inside the combustion furnace (110), a phenomenon in which the interior (R) of the reaction tube (130) is heated by the outer wall (W), and a phenomenon in which thermal energy is consumed by an ammonia decomposition reaction inside the reaction tube (130). However, the present invention is not necessarily limited thereto.

[0110] As an example, the simulation unit (230) can derive the pressure distribution, velocity distribution, and temperature distribution inside (R) the burner (120) and combustion furnace (110), or the reaction tube (130), by calculating the aforementioned governing equations in conjunction. At this time, the simulation unit (230) can perform calculations according to the governing equation for heat transfer (the fourth governing equation) for the computational grid region (the second grid) corresponding to the outer wall (W) of the reaction tube (130). As a result, the simulation unit (230) can derive the heat transfer efficiency of the ammonia decomposition reactor (100).

[0111] According to exemplary embodiments, the simulation unit (230) may be configured to calculate the amount of heat transfer of working fluids for the first grid, the second grid, and the third grid based on time data. In this way, by calculating the amount of heat transfer based on time data, the amount of heat transfer of the ammonia decomposition reactor (100) can be derived more accurately.

[0112] Figure 4 is a diagram illustrating the calculation of heat transfer amount based on time data of the simulation unit (230).

[0113] Referring to FIG. 4, the simulation unit (230) can perform calculations over the time steps matched for the first to third grids. That is, the first grid can perform calculations over the time steps matched for the first grid. The second grid can perform calculations over the time steps matched for the second grid. The third grid can perform calculations over the time steps matched for the third grid.

[0114] The simulation unit (230) can perform calculations repeatedly over time steps. As a result, the heat transfer efficiency within the ammonia decomposition reactor (100) can be predicted or verified more accurately.

[0115] According to exemplary embodiments, the simulation unit (230) can select the longest time step by comparing the first time step, the second time step, and the third time step, and can repeat calculations for the remaining time steps until the calculation for the longest time step is completed. As a result, the heat transfer efficiency in the actual reaction environment can be predicted more accurately, even though the heat transfer rates occurring in each component (110, 120, 130) in the ammonia decomposition reactor (100) are different. At this time, if multiple calculations are performed for the longest time step, calculations for other time steps can be repeated until the last calculation for the longest time step is completed.

[0116] The visualization unit (240) can visualize the simulation results for the ammonia decomposition reactor (100). For example, the visualization unit (240) can visualize the simulation results (e.g., temperature distribution, etc.) in the form of a heat map on a 2D or 3D object representing the ammonia decomposition reactor (100).

[0117] Various data related to the simulation of the ammonia decomposition reaction may be stored in the DB (250). For example, the DB (250) may store basic simulation data according to the type of the ammonia decomposition reactor (100). For example, basic simulation data according to the type of catalyst provided to the reaction tube (130) may be stored. Alternatively, the DB (150) may store simulation results.

[0118] [Simulation Method]

[0119] A simulation method according to exemplary embodiments may include the steps of receiving simulation basic data (P100), constructing a CFD model (P200), and simulating an ammonia decomposition reaction using the CFD model.

[0120] FIG. 5 is a flowchart illustrating a simulation method according to exemplary embodiments. However, this is merely a preferred embodiment for achieving the purpose of the present disclosure, and it is understood that some steps may be added or deleted as necessary.

[0121] Each step of the simulation method may be performed by a computing device. In other words, each step of the method may be implemented by one or more instructions executed by a processor of the computing device. All steps included in the method may be executed by a single physical computing device, or they may be distributed and executed by multiple physical computing devices. For example, the first steps of the method may be performed by a first computing device, and the second steps of the method may be performed by a second computing device. For ease of understanding, the following description will continue by assuming that each step of the method is performed by the simulation device (200) exemplified in FIG. 2. Therefore, in the following description, if the subject of each operation is omitted, it can be understood that it is performed by the device (200) exemplified above.

[0122] Steps P100 to P400 illustrated in FIG. 5 can each be performed by a data input unit (210), a model configuration unit (220), a simulation unit (230), and a visualization unit (240).

[0123] As illustrated in FIG. 5, the simulation method may start at step P100, which receives simulation basic data regarding the ammonia decomposition reaction. For this step, further reference should be made to the description of the data input unit (210).

[0124] In step P200, a CFD model can be constructed based on input simulation basic data. For example, the simulation device (200) can construct a CFD model by generating a computational grid based on input simulation basic data, setting time steps considering heat transfer occurring in each component, setting governing equations, and setting initial conditions and boundary conditions. For this step, further reference should be made to the description of the model construction unit (220).

[0125] In step P300, the heat transfer phenomenon for the ammonia decomposition reaction can be simulated using the configured CFD model. For example, the simulation device (200) can simulate the ammonia decomposition reaction by calculating the governing equations according to the set initial and boundary conditions, and by matching each calculation grid with the time step to calculate the governing equations. The calculation of the governing equations can be performed in units of calculation cells that constitute the calculation grid. For this step, further reference should be made to the description of the simulation unit (230).

[0126] In step P400, the simulation results may be visualized. For example, the simulation device (200) may visualize the simulation results on a two-dimensional or three-dimensional object pointing to the ammonia decomposition reactor (100). For example, the simulation device (200) may visualize the temperature distribution, etc., in the form of a heat map, etc. However, the visualization method is not limited to this. For this step, further reference should be made to the description of the visualization unit (240).

[0127] Although the invention has been described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims.

Claims

1. A data input unit configured to receive simulation basic data including structural data of an ammonia decomposition reactor comprising a combustion furnace, a burner, and reaction tubes, physical property data of working fluids within the ammonia decomposition reactor, and time data related to heat transfer time within the ammonia decomposition reactor; A model configuration unit configured to construct a CFD (Computational Fluid Dynamics) model based on the above simulation basic data; and A simulation device comprising a simulation unit configured to simulate heat transfer phenomena occurring between the combustion furnace, burner, and reaction tube using the above CFD model.

2. In Paragraph 1, The above structural data is, First structural data associated with the above combustion furnace and burner, Second structural data associated with the outside of the above reaction tube, and A simulation device including third structural data associated with the interior of the above reaction tube.

3. In Paragraph 2, The above model components are, It includes a calculation area setting unit that generates a first grid, a second grid, and a third grid corresponding to each of the first structure data, the second structure data, and the third structure data, respectively, and The simulation unit is a simulation device configured to calculate the amount of heat transfer of working fluids for the first grid, the second grid, and the third grid based on the time data.

4. In Paragraph 3, The above model components are, Based on the above time data A first time step corresponding to heat transfer in the combustion furnace and burner above, A second time step corresponding to heat transfer at the outer wall of the reaction tube, and It includes a time step setting unit configured to set a third time step corresponding to heat transfer inside the reaction tube, and The above time step setting unit matches the first to third time steps to the first to third grids, respectively, and The above simulation unit is, A simulation device that performs calculations over time steps matched to the first to third grids.

5. In Paragraph 4, The above simulation unit is, The longest time step is selected by comparing the first time step, the second time step, and the third time step. A simulation device that repeatedly performs calculations for the remaining time steps until the calculation for the longest time step is completed.

6. In Paragraph 4, The above first to third time steps are a simulation device having different intervals.

7. In Paragraph 1, The above model components are, It includes a governing equation setting unit that sets a governing equation based on the above simulation basic data, and The governing equation setting unit sets the first governing equation, the second governing equation, the third governing equation, and the fourth governing equation as the governing equations of the CFD model, and The above first governing equation is an equation regarding mass transfer within the ammonia decomposition reactor, and The above second governing equation is an equation regarding the flow of the above working fluids, and The above third governing equation is an equation regarding the chemical reaction between the working fluids, and The above fourth governing equation is an equation regarding heat transfer within the ammonia decomposition reactor, Simulation device.

8. In Paragraph 7, The above governing equation setting unit is, A simulation device for further establishing a fifth governing equation for the pressure drop inside the reaction tube.

9. In Paragraph 3, The above calculation area setting unit is, A simulation device that increases the number of computational cells included in each grid as the number of types of components participating in a chemical reaction increases in each grid.

10. In Paragraph 9, A simulation device in which the number of calculation cells of the first grid is greater than the number of calculation cells of the second grid.

11. In Paragraph 9, A simulation device in which the number of calculation cells of the third grid is greater than the number of calculation cells of the second grid.

12. In Paragraph 9, A simulation device in which the number of calculation cells of the third grid is less than the number of calculation cells of the first grid.

13. In Paragraph 1, The above model components are, A computational area setting unit that generates a computational grid based on the above structural data; A time step setting unit that sets a plurality of time steps based on the above time data; and A simulation device comprising: a governing equation setting unit for setting a governing equation based on the above material property data.

14. A method for simulating an ammonia decomposition reaction performed on a computing device, A step of receiving simulation basic data including structural data of an ammonia decomposition reactor comprising a combustion furnace, a burner, and reaction tubes, physical property data of working fluids within the ammonia decomposition reactor, and time data related to heat transfer time within the ammonia decomposition reactor; A step of constructing a CFD (Computational Fluid Dynamics) model based on the above simulation basic data; and A simulation method comprising the step of simulating the heat transfer phenomenon occurring between the combustion furnace, burner, and reaction tube using the above CFD model.

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