A method and system for simulating high-temperature hydrothermal oxidation of organic matter in a porous wall reactor

Abstract

The present invention discloses a simulation method and system for a high-temperature hydrothermal oxidation process of organic matter in a porous wall reactor, and belongs to the technical field of hydrothermal oxidation simulation. With a porous wall reactor as the calculation object, numerical simulation of the high-temperature hydrothermal oxidation process of organic matter, the heat and mass transfer process and the flow process coupling is performed with the aid of ANSYS FLUENT software. The present invention can obtain comprehensive information such as reactor center axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer and temperature field distribution in a porous wall reactor; it can also be used to optimize operating parameters and structural parameters, and guide the acquisition of excellent protective films and reactor temperature distribution in porous wall reactors, thereby reducing the risk of reactor corrosion and salt deposition.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrothermal oxidation simulation, and in particular relates to a simulation method and system for a high-temperature hydrothermal oxidation process of organic matter in a porous wall reactor. Background Art

[0002] Industrial wastewater has a high organic concentration, COD can reach more than 10,000 mg / L, or even tens of thousands to hundreds of thousands of mg / L; the composition of industrial wastewater is complex, containing toxic and harmful substances, most of which are aromatic compounds and heterocyclic compounds, and also contain sulfides, nitrides, heavy metals and toxic organic matter; due to the strong acidity and alkalinity and high salt content of industrial wastewater, it is easy to cause corrosion and blockage of the reactor. In recent years, high-temperature hydrothermal oxidation treatment technology of organic wastewater represented by supercritical water oxidation has been vigorously developed due to its many advantages. Supercritical water is completely miscible with organic matter and gas, and can form a uniform mixture without mass transfer resistance. It can obtain an organic matter degradation rate of 99.99% within tens of seconds, and the generated NOx, SO2 and other secondary pollutants are negligible, and heavy metals are fixed in the solid phase residue. However, organic wastewater with high salt content and strong corrosion characteristics will seriously corrode the reactor, and the solubility of most inorganic salts is significantly reduced at high temperatures, so that they precipitate and adsorb on the surface of the equipment, causing heat transfer deterioration and reactor blockage. Therefore, it is crucial to design a reactor with resistance to corrosion and salt deposition, among which the porous wall reactor is an excellent reactor with such characteristics.

[0003] However, during the high-temperature hydrothermal oxidation process of organic matter, the porous wall reactor has the characteristics of high temperature, high pressure, complex components, intense heat and mass transfer processes, complex fluid flow conditions, and difficulty in measuring temperature field and protective film information. The harsh reaction environment makes it difficult for existing experimental methods to obtain flow field and temperature field information in the porous wall reactor. In addition, the current experimental method is also limited by the size of the porous wall reactor. Thermocouples will interfere with the temperature and protective film formation in the porous wall reactor. Therefore, the measurement is limited to individual measuring points, and it is difficult to fully grasp the real information in the porous wall reactor. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a simulation method and system for the high-temperature hydrothermal oxidation process of organic matter in a porous wall reactor, so as to solve the technical problem that the prior art cannot test and obtain comprehensive flow field and temperature field information in the porous wall reactor, thereby guiding the optimization design of the structure and operating parameters of the porous wall reactor.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention discloses a method for simulating a high-temperature hydrothermal oxidation process of organic matter in a porous wall reactor, comprising the following steps:

[0007] S1: setting physical model parameters according to the structure and size of the porous wall reactor;

[0008] S2: According to the physical model parameters, a two-dimensional or three-dimensional physical model including a reactor wall, a porous wall, an organic matter and oxidant inlet, a cryogenic protection liquid or gas inlet, and a reactor outlet is established, and meshing is performed to obtain a mesh file of the physical model;

[0009] S3: Based on the grid file of the physical model, a numerical calculation model including energy equation, turbulence model, reaction kinetics model, component transport model and porous media model is established;

[0010] S4: Import the quantitative relationship between material property parameters and temperature into ANSYS FLUENT software;

[0011] S5: Set the boundary conditions of the computational domain;

[0012] S6: Numerical simulation calculation of the coupled process of high-temperature hydrothermal oxidation of organic matter, heat and mass transfer and flow in the porous wall reactor was performed to obtain the reactor center axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer and temperature field distribution in the porous wall reactor;

[0013] S7: Use ANSYS FLUENT or post-processing software TECPLOT to post-process the results of S6 numerical simulation calculations to obtain information on reactor center axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer, and temperature field distribution in the porous wall reactor, so as to optimize operating parameters and structural parameters, and form a high protective film coverage on the inner surface of the porous wall of the porous wall reactor (theoretically, the larger the better, that is, the closer to 1 the better) to prevent the high-temperature corrosive fluid in the reactor from eroding the porous wall, thereby reducing the risk of reactor corrosion and salt deposition.

[0014] Preferably, in S1, the physical model parameters include the diameter of the organic matter and oxidant inlets, the diameter of the cryogenic protection liquid or gas inlet, the position of the cryogenic protection liquid or gas inlet, the number of cryogenic protection liquid or gas inlets, the reactor outlet diameter, the reactor length, the porous wall diameter, the porous wall thickness, the porous wall porosity and the reactor annulus size.

[0015] Preferably, in S2, ANSYS ICEM or GAMBIT software is used to establish and obtain a mesh file of the physical model.

[0016] Preferably, in S3, the mesh file of the physical model is imported into ANSYS FLUENT software to establish a numerical calculation model including an energy equation, a turbulence model, a reaction kinetics model, a component transport model and a porous medium model.

[0017] Further preferably, the Realizable k-ε model is used as the turbulence model for numerical simulation calculation in the porous wall reactor;

[0018] An ethanol solution was used as a simulated organic matter, and an ethanol oxidation reaction was used as a simulated organic matter oxidation reaction;

[0019] The finite rate / eddy dissipation model is used as the reaction kinetics model for numerical simulation calculations in porous wall reactors.

[0020] Preferably, in S4, the quantitative relationship between the material property parameters and temperature is calculated using the following method:

[0021] The physical properties of the reactants and products in the porous wall reactor are calculated using the weighted average values ​​of the pure components; the physical properties include density, specific heat at constant pressure, thermal conductivity and viscosity coefficient;

[0022] The diffusion coefficient of the high temperature fluid in the porous wall reactor is expressed by the diffusion coefficient of pure water.

[0023] Preferably, in S5, setting the boundary conditions of the computational domain specifically includes:

[0024] Adiabatic boundary conditions were used for the reactor wall;

[0025] The organic matter and oxidant inlets, cryogenic protection liquid or gas inlets all use mass inlet boundary conditions;

[0026] The reactor outlet adopts the pressure outlet boundary condition;

[0027] The pressure in the reactor was set to the desired pressure.

[0028] Further preferably, the boundary conditions of the organic matter and oxidant inlets should determine and set the solution concentration, solution flow rate, solution preheating temperature, peroxygen coefficient, hydraulic diameter and turbulence intensity; the boundary conditions of the low-temperature protection liquid or gas inlet should determine and set the low-temperature protection liquid or gas flow rate, low-temperature protection liquid or gas preheating temperature, hydraulic diameter and turbulence intensity parameters.

[0029] Preferably, the coverage of the protective film is the ratio of the flow rate of the low-temperature protective liquid or gas at the inner surface of the porous wall to the total flow rate of the fluid.

[0030] The present invention also discloses a simulation system for realizing the high-temperature hydrothermal oxidation process of organic matter in the porous wall reactor, comprising:

[0031] A physical model mesh file acquisition module is used to set physical model parameters according to the structure and size of the porous wall reactor, and then establish a two-dimensional or three-dimensional physical model including the reactor wall, porous wall, organic matter and oxidant inlet, cryogenic protection liquid or gas inlet and reactor outlet, and perform meshing;

[0032] A numerical calculation model building module is used to build a numerical calculation model including energy equation, turbulence model, reaction kinetics model, component transport model and porous medium model according to the grid file of the physical model;

[0033] The module for calculating the variation of material properties with temperature is used to import the quantitative relationship between material properties and temperature into ANSYS FLUENT software for calculation;

[0034] A calculation domain boundary condition setting module is used to set the calculation domain boundary conditions;

[0035] Numerical simulation calculation module, used to perform numerical simulation calculation on the coupled process of high-temperature hydrothermal oxidation of organic matter, heat and mass transfer and flow in the porous wall reactor, and obtain the distribution of reactor center axis temperature, protective film temperature and protective film coverage in the porous wall reactor;

[0036] The post-processing module is used to post-process the numerical simulation calculation results using ANSYS FLUENT or post-processing software TECPLOT to obtain the information on the reactor axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer, and temperature field distribution in the porous wall reactor, so as to optimize the operating parameters and structural parameters and obtain excellent protective film and reactor temperature distribution in the porous wall reactor.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The method for simulating the high-temperature hydrothermal oxidation process of organic matter in a porous wall reactor disclosed in the present invention takes the porous wall reactor as the calculation object, and uses software to perform numerical simulation of the high-temperature hydrothermal oxidation process of organic matter, the heat and mass transfer process and the flow process coupled in the porous wall reactor, so as to obtain comprehensive information such as the reactor central axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer and temperature field distribution in the porous wall reactor. Therefore, it can be used to optimize operating parameters and structural parameters, and guide the acquisition of excellent protective film and reactor temperature distribution in the porous wall reactor, thereby reducing the risk of reactor corrosion and salt deposition. The method of the present invention can obtain comprehensive information such as reactor center axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer, and temperature field distribution in a porous wall reactor that are difficult to measure by experimental methods; the established simulation method can be used to optimize the operating parameters (organic matter flow rate, organic matter concentration, organic matter preheating temperature, low-temperature protection liquid or gas flow rate and temperature, etc.) and structural parameters (reactor length, porous wall diameter, porous wall porosity, porous wall thickness, reactor annular gap, number and position of low-temperature protection liquid or gas inlets, etc.) of the porous wall reactor, and guide the acquisition of an excellent protective film and reactor temperature distribution in the porous wall reactor, thereby reducing the risk of reactor erosion by corrosive substances and reactor blockage caused by salt deposition; in addition, the simulation method has the advantages of short cycle and low cost that are incomparable to the experimental method. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a simplified physical model of a porous wall reactor;

[0040] Figure 2 The change of the reactor axis temperature with the reactor length in the porous wall reactor;

[0041] Figure 3 The water film temperature and water film coverage in the porous wall reactor vary with the length of the reactor;

[0042] Figure 4 is the reactor temperature at different reactor length positions along the reactor diameter in a porous wall reactor. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0046] The present invention provides a simulation method for a high-temperature hydrothermal oxidation process of organic matter in a porous wall reactor, comprising the following steps:

[0047] S1: Setting physical model parameters according to the structure and size of the porous wall reactor actually in operation, the physical model parameters including the diameter of the organic matter and oxidant inlet, the diameter of the cryogenic protection liquid or gas inlet, the position of the cryogenic protection liquid or gas inlet, the number of cryogenic protection liquid or gas inlets, the reactor outlet diameter, the reactor length, the porous wall diameter, the porous wall thickness, the porous wall porosity and the reactor annular gap size.

[0048] S2: According to the physical model parameters, a two-dimensional or three-dimensional physical model including the reactor wall, porous wall, organic matter and oxidant inlet, cryogenic protection liquid or gas inlet and reactor outlet is established by using ANSYS ICEM or GAMBIT software, and meshing is performed to obtain a mesh file of the physical model;

[0049] S3: Import the mesh file of the physical model into ANSYS FLUENT software to establish a numerical calculation model including energy equation, turbulence model, reaction kinetics model, component transport model and porous medium model, as follows: the Realizable k-ε model is used as the turbulence model for numerical simulation calculation in the porous wall reactor; ethanol solution is used as the simulated organic matter, and ethanol oxidation reaction is used as the simulated organic matter oxidation reaction; the finite rate / eddy dissipation model is used as the reaction kinetics model for numerical simulation calculation in the porous wall reactor.

[0050] S4: In ANSYS FLUENT software, a quantitative relationship between material physical property parameters and temperature is established and imported with the help of user-defined functions. The quantitative relationship between material physical property parameters and temperature is calculated by the following method: the physical property parameters of reactants and products in the porous wall reactor are calculated by the weighted average value of pure components; wherein the physical property parameters include density, constant pressure specific heat, thermal conductivity and viscosity coefficient; the diffusion coefficient of the high temperature fluid in the porous wall reactor is represented by the diffusion coefficient of pure water.

[0051] S5: Set the boundary conditions of the calculation domain: the reactor wall adopts adiabatic boundary conditions; the organic matter and oxidant inlets, and the cryogenic protection liquid or gas inlets all adopt mass inlet boundary conditions; among them, the boundary conditions of the organic matter and oxidant inlets must determine and set the solution concentration, solution flow rate, solution preheating temperature, peroxygen coefficient, hydraulic diameter and turbulence intensity; the boundary conditions of the cryogenic protection liquid or gas inlet must determine and set the cryogenic protection liquid or gas flow rate, cryogenic protection liquid or gas preheating temperature, hydraulic diameter and turbulence intensity parameters; the reactor outlet adopts pressure outlet boundary conditions; the pressure inside the reactor is set to the required pressure.

[0052] S6: Perform numerical simulation calculations.

[0053] S7: Use ANSYS FLUENT or post-processing software TECPLOT to post-process the calculation results to obtain comprehensive information such as reactor center axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer, and temperature field distribution in the porous wall reactor, so as to optimize the operating parameters and structural parameters, guide the acquisition of excellent protective film and reactor temperature distribution in the porous wall reactor, thereby reducing the risk of reactor corrosion and salt deposition.

[0054] Example 1

[0055] This embodiment uses Figure 1 The porous wall reactor shown in the structure is the calculation object. The high-temperature hydrothermal oxidation process of the organic ethanol solution in the porous wall reactor is simulated by ANSYS FLUENT software, and the heat and mass transfer process and flow process coupling between the low-temperature protection water and the main fluid are numerically simulated to obtain the distribution of the temperature field, water film temperature and water film coverage in the reactor. The following steps are included:

[0056] S1: The physical model parameters are set according to the structure and size of the porous wall reactor in actual operation: the inlet diameters of organic matter and oxidant, the inlet diameter of low-temperature protection water and the reactor outlet diameter are set to 0.0028m, 0.003m and 0.006m respectively; the length of the porous wall reactor and the porous wall diameter are set to 0.146m and 0.048m respectively; the low-temperature protection water is injected into the reactor in three layers, which are located at 0m, 0.036m and 0.060m from the top of the reactor respectively; the porous wall porosity, porous wall thickness and reactor annulus are set to 0.4, 0.002m and 0.004m respectively.

[0057] S2: According to the physical model parameters, ANSYS ICEM or GAMBIT software is used to establish a two-dimensional physical model of the porous wall reactor and perform mesh division, with a total of 425,652 meshes.

[0058] S3: Import the mesh file of the physical model into ANSYS FLUENT software to establish the calculation model:

[0059] 1) In most areas of the porous wall reactor, the complex fluid flow is in a turbulent state, especially in the transcritical zone where the physical properties, temperature gradient and velocity gradient change dramatically, and strong eddy zones are easily formed. Since the Realizable k-ε has high precision characteristics, it can be well applied to flow fields with circulation zones, strong eddies and high velocity gradients, and the Realizable k-ε model satisfies the constraints on Reynolds stress and can maintain consistency with real turbulence in Reynolds stress, so the Realizable k-ε model is used as the turbulence model for numerical simulation calculations in porous wall reactors.

[0060] 2) Using ethanol solution as simulated organic matter, and ethanol oxidation reaction as simulated organic matter oxidation reaction.

[0061] 3) For the high-temperature hydrothermal oxidation process in a porous wall reactor, the chemical reaction interacts and influences the turbulent process, resulting in the reaction process being affected by both the molecular diffusion rate and the reaction kinetics. The finite rate / eddy dissipation model compares the chemical reaction rate with the eddy dissipation reaction rate, and then selects a smaller reaction rate that can truly reflect the reaction and flow characteristics. This model is more suitable for complex processes in porous wall reactors, so it is used as the reaction kinetic model for simulation calculations in porous wall reactors.

[0062] 4) The porous wall is set as the porous medium region, and the porosity is set to 0.4.

[0063] S4: In ANSYS FLUENT software, the quantitative relationship between the density, constant pressure specific heat, thermal conductivity and viscosity coefficient of C2H6O, O2, CO2, H2O(g) and H2O(l) and temperature is established and imported with the help of user-defined functions. The reactants and products in the porous wall reactor are mixtures, and the physical property parameters are calculated using the weighted average of the pure components. The diffusion coefficient of the high-temperature fluid in the porous wall reactor is expressed by the diffusion coefficient of pure water.

[0064] S5: The reactor wall adopts adiabatic boundary conditions, the organic matter and oxidant inlets and the cryogenic protection water inlet adopt mass inlet boundary conditions, the reactor outlet adopts pressure outlet boundary conditions, and the pressure in the reactor is set to 23MPa. The ethanol solution concentration, ethanol solution flow rate, ethanol solution preheating temperature, peroxygen coefficient, hydraulic diameter and turbulence intensity parameters are set to 15%, 1L / h, 723K, 1.25, 2.8 and 3 respectively. The cryogenic protection water flow rate, cryogenic protection water preheating temperature, hydraulic diameter and turbulence intensity are set to 0.4L·h -1 , 523K, 3 and 0.

[0065] S6: Perform numerical simulation calculations.

[0066] S7: Use ANSYS FLUENT or post-processing software TECPLOT to post-process the calculation results to obtain the distribution of reactor center axis temperature, water film temperature and water film coverage, such as Figure 2 and 3 As shown, the water film temperature is basically below the supercritical temperature (<647.15K) throughout the entire length of the reactor, and the water film coverage rate reaches about 98% in the lower and middle parts of the reactor and about 55% in the upper part, which can better protect the reactor from erosion by the high-temperature fluid in the reactor. Figure 4 As shown, an upper supercritical oxidation zone and a lower subcritical salt dissolution zone for redissolving the inorganic salts produced from the supercritical zone are formed in the reactor.

[0067] In summary, the present invention can obtain comprehensive information such as reactor center axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer, and temperature field distribution in a porous wall reactor; it can also be used to optimize operating parameters and structural parameters, and guide the acquisition of excellent protective films and reactor temperature distribution in porous wall reactors, thereby reducing the risks of reactor corrosion and salt deposition.

[0068] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for simulating a high-temperature hydrothermal oxidation process of organic matter in a porous wall reactor, characterized in that: The following steps are involved: S1: setting physical model parameters according to the structure and size of the porous wall reactor; S2: According to the physical model parameters, a two-dimensional or three-dimensional physical model including a reactor wall, a porous wall, an organic matter and oxidant inlet, a cryogenic protection liquid or gas inlet, and a reactor outlet is established, and meshing is performed to obtain a mesh file of the physical model; S3: Based on the grid file of the physical model, a numerical calculation model including energy equation, turbulence model, reaction kinetics model, component transport model and porous media model is established; S4: Import the quantitative relationship between the material property parameters and the temperature in the ANSYS FLUENT software; the quantitative relationship between the material property parameters and the temperature is calculated using the following method: The physical properties of the reactants and products in the porous wall reactor are calculated using the weighted average of the pure components; the physical properties include density, specific heat at constant pressure, thermal conductivity and viscosity coefficient; The diffusion coefficient of the high-temperature fluid in the porous wall reactor is expressed by the diffusion coefficient of pure water; S5: Set the boundary conditions of the computational domain, including: Adiabatic boundary conditions were used for the reactor wall; The organic matter and oxidant inlets, cryogenic protection liquid or gas inlets all use mass inlet boundary conditions; The reactor outlet adopts the pressure outlet boundary condition; The pressure in the reactor is set to the desired pressure; S6: Numerical simulation calculation of the coupled process of high-temperature hydrothermal oxidation of organic matter, heat and mass transfer and flow in the porous wall reactor was performed to obtain the reactor center axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer and temperature field distribution in the porous wall reactor; S7: Post-process the results of the numerical simulation calculation in S6 using ANSYS FLUENT or the post-processing software TECPLOT to obtain information on the reactor axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer, and temperature field distribution in the porous wall reactor, so as to optimize the operating parameters and structural parameters, form a high protective film coverage on the inner surface of the porous wall of the porous wall reactor, and thus reduce the risk of reactor corrosion and salt deposition.

2. The method for simulating high temperature hydrothermal oxidation of organic matter in a porous wall reactor according to claim 1, characterized in that: In S1, the physical model parameters include the diameter of the organic matter and oxidant inlet, the diameter of the cryogenic protection liquid or gas inlet, the position of the cryogenic protection liquid or gas inlet, the number of cryogenic protection liquid or gas inlets, the reactor outlet diameter, the reactor length, the porous wall diameter, the porous wall thickness, the porous wall porosity and the reactor annulus size.

3. The method for simulating high temperature hydrothermal oxidation of organic matter in a porous wall reactor according to claim 1, characterized in that: In S2, ANSYS ICEM or GAMBIT software is used to establish and obtain the mesh file of the physical model.

4. The method for simulating high temperature hydrothermal oxidation of organic matter in a porous wall reactor according to claim 1, characterized in that: In S3, the mesh file of the physical model is imported into ANSYS FLUENT software to establish a numerical calculation model including energy equation, turbulence model, reaction kinetics model, component transport model and porous media model.

5. The method for simulating high temperature hydrothermal oxidation of organic matter in a porous wall reactor according to claim 4, characterized in that: Adopting Realizable k- The model is used as a turbulence model for numerical simulation calculations in porous wall reactors; An ethanol solution was used as a simulated organic matter, and an ethanol oxidation reaction was used as a simulated organic matter oxidation reaction; The finite rate / eddy dissipation model is used as the reaction kinetics model for numerical simulation calculations in porous wall reactors.

6. The method for simulating high temperature hydrothermal oxidation of organic matter in a porous wall reactor according to claim 1, characterized in that: The boundary conditions for the inlet of organic matter and oxidant shall determine and set the solution concentration, solution flow rate, solution preheating temperature, peroxygen coefficient, hydraulic diameter and turbulence intensity; the boundary conditions for the inlet of low-temperature protection liquid or gas shall determine and set the low-temperature protection liquid or gas flow rate, low-temperature protection liquid or gas preheating temperature, hydraulic diameter and turbulence intensity parameters.

7. The method for simulating high temperature hydrothermal oxidation of organic matter in a porous wall reactor according to claim 1, characterized in that: The protective film coverage is the ratio of the low-temperature protective liquid or gas flow rate at the inner surface of the porous wall to the total fluid flow rate.

8. A simulation system for realizing a high temperature hydrothermal oxidation process of organic matter in a porous wall reactor as claimed in any one of claims 1 to 7, characterized in that: include: A physical model mesh file acquisition module is used to set physical model parameters according to the structure and size of the porous wall reactor, and then establish a two-dimensional or three-dimensional physical model including the reactor wall, porous wall, organic matter and oxidant inlet, cryogenic protection liquid or gas inlet and reactor outlet, and perform meshing; A numerical calculation model building module is used to build a numerical calculation model including energy equation, turbulence model, reaction kinetics model, component transport model and porous medium model according to the grid file of the physical model; The module for calculating the variation of material properties with temperature is used to import the quantitative relationship between material properties and temperature into ANSYS FLUENT software for calculation; A calculation domain boundary condition setting module is used to set the calculation domain boundary conditions; Numerical simulation calculation module, used to perform numerical simulation calculation on the coupled process of high-temperature hydrothermal oxidation of organic matter, heat and mass transfer and flow in the porous wall reactor, and obtain the distribution of reactor center axis temperature, protective film temperature and protective film coverage in the porous wall reactor; The post-processing module is used to post-process the numerical simulation calculation results using ANSYS FLUENT or post-processing software TECPLOT to obtain the information on the reactor axis temperature, protective film temperature, protective film coverage, fluid flow, heat and mass transfer, and temperature field distribution in the porous wall reactor, so as to optimize the operating parameters and structural parameters and obtain excellent protective film and reactor temperature distribution in the porous wall reactor.

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