Numerical simulation method and device for coal in-situ ignition combustion and electronic equipment

Abstract

The application provides a numerical simulation method and device for in-situ ignition and combustion of coal and electronic equipment. The method comprises the following steps: establishing a fuel combustion model and a coal in-situ combustion model comprising a discrete phase particle model, solving the in-situ ignition and combustion model by using a control model, and updating the physical and chemical property parameters of the coal seam. The application simulates the fuel movement process and combustion reaction by establishing a discrete phase particle model, improves the accuracy of model simulation, controls the injection of combustion-supporting material, cooling liquid and fuel parameters of the discrete phase particle model and the coal in-situ combustion model, realizes the whole process of multi-parameter regulation of the combustion reaction of the coal seam, enhances the adaptability of the simulation method to various actual operation conditions and ignition modes, and improves the accuracy of model calculation by continuously updating the physical and chemical property parameters of the coal seam.

Description

Technical Field

[0001] This application relates to the field of in-situ coal combustion technology, and in particular to a numerical simulation method, apparatus and electronic equipment for in-situ coal ignition and combustion. Background Technology

[0002] Underground coal gasification is a revolutionary coal mining technology that involves the in-situ controlled combustion of underground coal, producing combustible gases such as methane, hydrogen, and carbon monoxide through thermal and chemical reactions. With the development of science and technology, this technology transforms traditional physical coal mining into chemical mining, representing a crucial way to achieve "no one underground, no coal on the surface," and is also a new technology for deep (≥1000m) coal mining.

[0003] Numerical simulation, leveraging the powerful computing capabilities of computers, can fully consider various physicochemical parameters in the gas and solid phases of underground coal seams. By utilizing the conservation of mass, momentum, energy, and elements, it can quickly, efficiently, and comprehensively simulate the changes in physical fields such as temperature and concentration in underground coal seams during in-situ ignition combustion. This provides important reference value for the selection of physical parameters in actual production.

[0004] In coal seam combustion reaction simulation, it is difficult to achieve multi-parameter control of the entire reaction process and real-time updates of coal seam physical parameters, which limits the accuracy of predicting underground coal seam combustion processes. Summary of the Invention

[0005] This application provides a numerical simulation method, apparatus, and electronic equipment for in-situ ignition combustion of coal, in order to solve the limitations and accuracy problems of simulating coal seam combustion reactions.

[0006] Firstly, this application provides a numerical simulation method for in-situ ignition combustion of coal, comprising:

[0007] A three-dimensional model of the target area is established, and the model is meshed; the target area includes the horizontal well combustion zone and the coal seam reaction zone.

[0008] A fuel combustion model of the fuel in the combustion zone is established based on a three-dimensional model;

[0009] A three-dimensional model was established to create an in-situ coal combustion model when the coal seam reaction zone provides an external heat source in the combustion zone.

[0010] The fuel combustion model and the coal in-situ combustion model were solved to obtain the simulation results of coal in-situ ignition combustion.

[0011] Optionally, the fuel is injected into the combustion zone in an atomized state;

[0012] A fuel combustion model within the combustion zone is established based on a three-dimensional model, specifically including:

[0013] A discrete phase particle model of the fuel and a combustion reaction model of the fuel were established based on a three-dimensional model.

[0014] Optionally, an in-situ coal combustion model is established based on a three-dimensional model when the coal seam reaction zone provides an external heat source in the combustion zone, specifically including:

[0015] Based on the chemical reaction process in the coal seam reaction zone when the combustion zone provides an external heat source, a moisture evaporation model, a volatile matter separation and desorption model, a volatile matter combustion model, and a fixed carbon combustion gasification model are established.

[0016] Based on the physical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a control model based on fluid dynamics is established.

[0017] Based on the physical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a coal seam cavity evolution model is established.

[0018] Optionally, the fuel combustion model and the coal in-situ combustion model are solved to obtain simulation results of coal in-situ ignition combustion, specifically including:

[0019] It receives the injection parameters of coolant, combustion improver, and fuel, and solves the fuel combustion model based on these parameters to obtain the reactant parameters after fuel combustion.

[0020] The in-situ combustion model of coal is solved based on the reactant parameters after fuel combustion to obtain the simulation results of in-situ ignition combustion of coal.

[0021] Secondly, this application provides a numerical simulation device for in-situ ignition combustion of coal, comprising:

[0022] A module is established to create a 3D model of the target area and to mesh the 3D model; the target area includes the horizontal well combustion zone and the coal seam reaction zone.

[0023] The module is also used to build a fuel combustion model of the fuel in the combustion zone based on a three-dimensional model;

[0024] The module is also used to establish an in-situ combustion model of coal in the coal seam reaction zone when the combustion zone provides an external heat source, based on a three-dimensional model;

[0025] The solver module is used to solve the fuel combustion model and the coal in-situ combustion model to obtain the simulation results of coal in-situ ignition combustion.

[0026] Optionally, the fuel is injected into the combustion zone in an atomized state;

[0027] Create a module, specifically for:

[0028] A discrete phase particle model of the fuel and a combustion reaction model of the fuel were established based on a three-dimensional model.

[0029] Optionally, the module is specifically used for:

[0030] Based on the chemical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a moisture evaporation model, a volatile matter separation and desorption model, a fixed carbon combustion model, and a fixed carbon gasification model are established.

[0031] Based on the physical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a control model based on fluid dynamics is established.

[0032] Based on the physical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a coal seam cavity evolution model is established.

[0033] Optionally, the module is specifically used for:

[0034] It receives the injection parameters of coolant, combustion improver, and fuel, and solves the fuel combustion model based on these parameters to obtain the reactant parameters after fuel combustion.

[0035] The in-situ combustion model of coal is solved based on the reactant parameters after fuel combustion to obtain the simulation results of in-situ ignition combustion of coal.

[0036] Thirdly, this application provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0037] The memory stores instructions that the computer executes;

[0038] The processor executes computer-executable instructions stored in memory to implement the methods described in the first aspect above.

[0039] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method described in the first aspect above.

[0040] This application provides a numerical simulation method, apparatus, and electronic equipment for in-situ coal combustion. By establishing a discrete phase particle model, it simulates the movement of droplet particles formed by fuel atomization through a nozzle and the fuel combustion reaction, thereby simulating the chemical changes in the coal seam and improving the accuracy of the model simulation. By adjusting different injection parameters in the discrete phase particle model and the in-situ coal combustion model, it realizes multi-parameter control functions in the coal combustion process, improving the model's adaptability to various actual operating conditions. Based on the simulation results obtained from the computational fluid dynamics control model, it calculates the changes in the physicochemical properties of the coal seam during the reaction process, which is used to update the physicochemical property parameters of the coal seam in real time, improving the accuracy of the model calculation. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0042] Figure 1 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in an embodiment of this application;

[0043] Figure 2 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in an embodiment of this application;

[0044] Figure 3 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in an embodiment of this application;

[0045] Figure 4 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in an embodiment of this application;

[0046] Figure 5 A schematic diagram of the temperature distribution in a horizontal well for in-situ ignition combustion of coal is provided as an embodiment of this application.

[0047] Figure 6 A flowchart illustrating the solution process of a numerical simulation method for in-situ ignition combustion of coal provided in this application embodiment;

[0048] Figure 7 A schematic diagram of the temperature distribution of a coal seam and a horizontal well during in-situ ignition combustion of coal, provided as an embodiment of this application;

[0049] Figure 8 A schematic diagram of coal seam porosity distribution during in-situ ignition combustion of coal is provided as an embodiment of this application.

[0050] Figure 9 A schematic diagram of the structure of a numerical simulation device for in-situ ignition combustion of coal provided in an embodiment of this application;

[0051] Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0052] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0053] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0054] Figure 1 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in this application embodiment is shown below. Figure 1 As shown, this numerical simulation method includes the following steps:

[0055] S101. Establish a three-dimensional model of the target area and perform mesh generation on the three-dimensional model.

[0056] More specifically, the target area comprises two parts: the horizontal well combustion zone and the coal seam reaction zone. Both the horizontal well combustion zone and the coal seam reaction zone are scaled down according to their actual dimensions. Mesh generation includes the establishment of boundary layers.

[0057] For example, boundary layer delineation is performed on the wall surface of the combustion zone of a horizontal well that is close to the coal seam reaction zone.

[0058] S102. Establish a fuel combustion model for the fuel in the combustion zone based on a three-dimensional model.

[0059] More specifically, a combustion model of liquid fossil fuels within the horizontal well combustion zone is established based on a three-dimensional model of the horizontal well combustion zone. The fuel includes liquid fossil fuels such as petroleum. The fuel combustion model specifically includes a discrete phase particle model and a fuel combustion reaction model, describing the combustion reaction of liquid fossil fuels after being atomized into particles through a nozzle and injected into the underground horizontal well, with simultaneously injected oxidizers. To avoid excessively high or low combustion temperatures of the liquid fossil fuels, the injection parameters of coolant and oxidizer in the discrete phase particle model are controlled. Specifically, temperature control can be achieved by adjusting the oxidizer injection rate and the coolant injection volume. The coolant includes liquid water, and the oxidizer includes oxygen.

[0060] For example, when the water-to-liquid ratio injected into a horizontal well is 2:1, and the temperature is 800 degrees Celsius, increasing the amount of liquid water injected may lower the temperature.

[0061] S103. Establish an in-situ coal combustion model based on a three-dimensional model when the coal seam reaction zone provides an external heat source in the combustion zone.

[0062] More specifically, the combustion of liquid fossil fuels in the combustion zone provides an external heat source for the coal seam reaction zone. By establishing an in-situ combustion model of the coal seam reaction zone based on a three-dimensional model, the coal seam reaction rate can be controlled by adjusting the oxidant and fuel injection parameters.

[0063] S104. Solve the fuel combustion model and the coal in-situ combustion model to obtain the simulation results of coal in-situ ignition combustion.

[0064] More specifically, by receiving the injection parameters of coolant, combustion oxidizer, and fuel, and based on these parameters, a fluid dynamics control model is used to solve the fuel combustion model to obtain the reactant parameters after fuel combustion. Then, based on these reactant parameters, an in-situ coal combustion model is solved to obtain the simulation results of in-situ coal ignition combustion. The coolant includes liquid water, the combustion oxidizer includes oxygen, the fuel includes liquid fossil fuels, and the simulation results of in-situ coal ignition combustion include the physicochemical properties of the coal seam, such as porosity.

[0065] In the numerical simulation method for in-situ coal combustion provided in this application, a discrete phase particle model is established to describe the movement of droplets formed by fuel through an atomizing nozzle and the combustion reaction, thereby improving the accuracy of the model. The coolant, combustion aid, and fuel parameters injected into the discrete phase particle model and the in-situ coal combustion model are adjusted to control the fuel combustion temperature and the coal seam reaction rate. The physicochemical properties of the coal seam are obtained by solving the reactant parameters after fuel combustion using a fluid dynamics control model, enabling real-time updating of the coal seam's physicochemical properties and improving the accuracy of the numerical simulation results.

[0066] Figure 2 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in this application embodiment is shown below. Figure 2 As shown, this numerical simulation method includes the following steps:

[0067] S201. Establish a discrete phase particle model of fuel based on a three-dimensional model.

[0068] More specifically, the discrete-phase particle model of fuel includes a description of the motion behavior and reaction process of liquid fossil fuel after entering a horizontal well, wherein the force balance of the particles in the discrete-phase particle model is calculated as follows:

[0069] (1)

[0070] in, For the mass of the droplet particles, The velocity of the flow phase. For particle velocity, The density of the mobile phase, For droplet density, For local gravitational acceleration, For reaction time, The particle relaxation time is calculated using the following formula:

[0071] (2)

[0072] in, The dynamic viscosity of the flow phase. The particle drag coefficient is selected according to empirical rules for round particles. Where is the droplet diameter, The fluid Reynolds number is calculated using the following formula:

[0073] (3)

[0074] S202. Establish a combustion reaction model of fuel based on a three-dimensional model.

[0075] More specifically, the fuel combustion reaction model involves liquid fossil fuel being atomized into particles through a nozzle and injected into a horizontal underground well, where it reacts with an oxidizer injected simultaneously from an injection parameter adjustment interface, wherein the fuel combustion rate... Calculated by the following formula:

[0076] (4)

[0077] in, Here, E is the pre-exponential factor, and c is the activation energy. The reaction order is... Determined based on fuel type. R is the reaction temperature and R is the gas constant.

[0078] In the numerical simulation method for in-situ ignition combustion of coal provided in this application, a discrete phase particle model is established to describe the movement of droplet particles formed by the atomization of liquid fossil fuel through a nozzle and the combustion reaction. By adjusting the parameters of the combustion improver and fuel injection, the droplet diameter, combustion improver injection speed, and injection volume can be set to adapt to various operating conditions, thus improving the accuracy of the model. The discrete phase particle model uses a single-step reaction of fuel and combustion improver to describe the combustion of liquid fossil fuel with oxygen, saving computational costs.

[0079] Figure 3 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in this application embodiment is shown below. Figure 3 As shown, this numerical simulation method includes the following steps:

[0080] S301. Establish a water evaporation model.

[0081] More specifically, a moisture evaporation model is established based on the chemical reaction process in the coal seam reaction zone when an external heat source is provided in the combustion zone. The moisture evaporation model includes: after liquid fossil fuel enters the connecting pipe, the hot flue gas released from combustion reaches the coal seam surface, heating the coal seam through conduction, convection, and radiation. Moisture in the coal seam evaporates and precipitates due to this heating. The moisture evaporation model is as follows:

[0082] (5)

[0083] Where M represents the moisture content of the coal received as a basis. This refers to the real-time moisture content of coal. The rate of water leaching from coal. For time (s), and Here, R represents the activation energy and pre-exponential factor for the coal water leaching rate, respectively, R is the universal gas constant, and T is the reaction temperature.

[0084] S302. Establish a model for analyzing volatile components.

[0085] More specifically, a volatile matter desorption model is established based on the chemical reaction process in the coal seam reaction zone when an external heat source is provided in the combustion zone. The volatile matter desorption model includes the following: during the heating process of coal, volatile matter decomposes into small molecule gases CO, CO2, H2, H2O, and CH4, which are then released. The volatile matter desorption model is as follows:

[0086] (6)

[0087] in, The volatile matter content of the coal received as a basis. This refers to the real-time volatile matter content of coal. Let be the volatile matter release rate of coal, E and A be the activation energy and pre-exponential factor of the volatile matter release rate, respectively, R be the universal gas constant, and T be the reaction temperature.

[0088] S303. Establish a volatile matter combustion model.

[0089] More specifically, a volatile matter combustion model is established based on the chemical reaction process in the coal seam reaction zone when the combustion zone provides an external heat source. The volatile matter combustion model includes reactions such as further oxidation combustion and steam reforming of the small molecule gases released after volatile matter decomposition.

[0090] For example, the expression for the CO combustion reaction rate is: ,in Let be the reaction rate constant for CO combustion, expressed as: Where A is the pre-exponential factor of the CO combustion rate, which can be 2.24e+12, and E is the activation energy of the CO combustion rate, which can be 107 kJ / mol.

[0091] The expression for the H2 combustion reaction rate is: ,in Let H2 be the reaction rate constant for combustion, expressed as: Where A is the pre-exponential factor of the H2 combustion rate, which can be 9.87e+8, and E is the activation energy of the H2 combustion rate, which can be 31 kJ / mol.

[0092] The expression for the CH4 combustion reaction rate is: ,in The reaction rate constant for the combustion of CH4 is expressed as: Where A is the pre-exponential factor of the CH4 combustion rate, which can be 2.12e+11, and E is the activation energy of the CH4 combustion rate, which can be 203 kJ / mol.

[0093] The rate expression for the H2O reforming reaction is: ,in The rate constant for H2O reforming is expressed as: Where A is the pre-exponential factor of the H2O reforming rate, which can be 2.78e+6, and E is the activation energy of the H2O reforming rate, which can be 12.5 kJ / mol.

[0094] S304. Establish a fixed carbon combustion gasification model.

[0095] More specifically, a fixed carbon combustion gasification model is established based on the chemical reaction process in the coal seam reaction zone when an external heat source is provided in the combustion zone. The fixed carbon combustion gasification model includes: the release of moisture and volatile matter from the coal, and the combustion of volatile matter. Because the atmosphere contains O2, CO2, and H2O, the fixed carbon will be ignited or gasified to produce CO2, CO, and H2. The fixed carbon combustion gasification model is as follows:

[0096] (7)

[0097] Where X is the fixed carbon conversion rate of coal. Let E and A represent the activation energy and pre-exponential factor of the coal combustion gasification rate, respectively, and R be the universal gas constant. The partial pressure of the oxidizing agent or vaporizing agent. Let n be the environmental pressure, and n be a constant.

[0098] S305. Establish a control model based on fluid mechanics.

[0099] More specifically, a fluid dynamics-based control model is established based on the physical reaction process of the coal seam reaction zone when an external heat source is provided in the combustion zone. This control model includes the continuity equation, momentum equation, energy equation, and component conservation equation for the porous medium model, as well as three user-defined scalar equations. The equation expressions are shown in the table below:

[0100] Table 1 Governing Equations

[0101]

[0102] in, For gas density, Porosity For the source phase of the continuity equation, For speed, For pressure, For dynamic viscosity, For penetration rate, For inertial drag factor, The specific heat capacity of a gas at constant pressure. For temperature, For solid density, The specific heat capacity at constant pressure of a solid. For effective thermal conductivity, For the energy equation source phase, Components The mass fraction, Components diffusion coefficient, Components The source phase of the transport equation, For custom scalars, scalar The scalar equation source phase is determined. Three custom scalar equations are used to track the reactivity of coal within each grid. The three values ​​of the subscript K in the scalar equations, 0, 1, and 2, correspond to the moisture, volatile matter, and fixed carbon of the coal, respectively. The reactivity of the coal includes coal seam physical parameters such as thermal conductivity, specific heat capacity, and gas-solid ratio. A semi-implicit segregated algorithm, the Segregated Implicit Solver, is used to solve the momentum equation, improving the convergence speed and convergence ability of the calculation. Simultaneously, the results calculated from the three scalar equations... The value controls the changes in the physicochemical properties of the coal seam during the reaction process.

[0103] For example, the porosity of a coal seam can be calculated using the following formula:

[0104] (8)

[0105] The initial porosity was determined based on relevant experimental results.

[0106] S306. Establish a coal seam cavity evolution model.

[0107] More specifically, a coal seam cavity evolution model is established based on the physical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source. The coal seam cavity evolution model is used to constitute the entire process of physical changes in the coal seam.

[0108] In the numerical simulation method for in-situ ignition combustion of coal provided in this application embodiment, a moisture evaporation model, a volatile matter separation and desorption model, a volatile matter combustion model, and a fixed carbon combustion gasification model are established based on the chemical reaction process of the coal seam reaction zone when an external heat source is provided in the combustion zone. A fluid dynamics-based control model and a coal seam cavity evolution model are established based on the physical reaction process. These chemical and physical models maximize the setting of physical and chemical parameters of the coal seam, and are universally applicable to different types of fossil fuels and coal seams of different depths. By calculating the governing equations and updating parameters such as coal seam porosity, the accuracy of predicting coal seam combustion properties is improved.

[0109] Figure 4 A flowchart illustrating a numerical simulation method for in-situ ignition combustion of coal provided in this application embodiment is shown below. Figure 4 As shown, the numerical simulation method for igniting and burning a 1000m underground lignite seam using n-heptane as fossil fuel at an operating pressure of 10MPa includes the following steps:

[0110] S41. Establish a three-dimensional model of the target area.

[0111] More specifically, the target area includes the horizontal well combustion zone and the coal seam reaction zone, which are two eccentric cylinders, with a boundary layer added to the wall of the inner cylinder of the horizontal well combustion zone.

[0112] S42. Establish a fuel combustion model for the fuel within the combustion zone.

[0113] More specifically, a fuel combustion model is established for the fuel in the combustion zone of an underground horizontal well. The fuel combustion model includes a discrete phase particle model of the fuel and a fuel combustion reaction model.

[0114] S43. Set fuel combustion inlet conditions.

[0115] More specifically, in establishing a fuel combustion model for fuel in the combustion zone of an underground horizontal well, inlet conditions for the fuel combustion model are set. These inlet conditions include combustion-supporting materials and fuel parameters in the discrete phase particle model. The combustion-supporting material includes oxygen, and the fuel may include heptane and heptane droplets.

[0116] For example, in a discrete phase particle model, an oxygen injection rate of 20 m / s, a heptane injection rate of 10 m / s, and a heptane droplet size of 0.2 mm are set to induce a combustion reaction, resulting in a steady-state combustion condition for heptane. The temperature distribution can then be predicted through calculation, as shown in the example of the horizontal well temperature distribution. Figure 5 As shown, the combustion of heptane results in different temperature distributions within the horizontal well.

[0117] S44. Establish an in-situ combustion model of coal when the coal seam reaction zone provides an external heat source in the combustion zone.

[0118] More specifically, an in-situ combustion model of coal in a horizontal underground well is established when the coal seam reaction zone provides an external heat source in the combustion zone. The in-situ combustion model includes models based on the chemical reaction processes of the coal seam reaction zone providing an external heat source, such as a moisture evaporation model, a volatile matter desorption model, a volatile matter combustion model, and a fixed carbon combustion gasification model; it also includes models based on the physical reaction processes of the coal seam reaction zone providing an external heat source, such as a coal seam cavity evolution model and a fluid dynamics-based control model. The in-situ combustion model sets relevant physical property parameters of the coal seam, including necessary parameters for model establishment, such as the original moisture content, volatile matter content, and coke content of the coal seam.

[0119] S45. Set in-situ combustion inlet conditions.

[0120] More specifically, based on the calculation results of the fuel combustion model, in-situ combustion inlet conditions are set in the coal in-situ combustion model of the underground horizontal well. The in-situ combustion inlet conditions include setting relevant gas parameters in the in-situ combustion model, wherein the gas may include O2, H2O and CO2.

[0121] For example, in a horizontal well with a temperature of 1000K generated by fuel combustion, the in-situ combustion model is used to set the molar composition of the inlet gas to 7.5% O2, 42.5% H2O, and 50% CO2, with a flow rate of 0.4 m / s and a flow direction perpendicular to the inlet surface. The outer boundary of the coal seam is defined as a constant-temperature wall, thereby generating a combustion gasification reaction of fixed carbon.

[0122] S46. Solve for the simulation results of coal ignition and combustion at the in-situ.

[0123] More specifically, the fuel combustion model and the coal in-situ combustion model are solved to obtain simulation results of coal in-situ ignition combustion. This includes receiving injection parameters for coolant, oxidizer, and fuel, and solving the fuel combustion model based on these parameters to obtain reactant parameters after fuel combustion. Then, the coal in-situ combustion model is solved based on these reactant parameters to obtain simulation results of coal in-situ ignition combustion. The coolant includes liquid water, the oxidizer includes oxygen, and the fuel includes liquid fossil fuels. The specific solution process for coal in-situ ignition combustion is as follows: Figure 6 As shown.

[0124] S4601, Start calculation.

[0125] S4602. Calculate the source terms of each equation.

[0126] More specifically, the source terms in each equation of the fuel combustion model and the coal in-situ combustion model are calculated, where the source terms include the corrections in the equations.

[0127] S4603, Solve the momentum equation.

[0128] More specifically, solve the momentum equation in the governing equations based on fluid mechanics.

[0129] S4604, Solve the continuity equation.

[0130] More specifically, solve the continuity equation in the governing equations based on fluid mechanics.

[0131] S4605, Solve the turbulence equation.

[0132] More specifically, the turbulence equations are solved, which are used to modify the equations of the fuel combustion model, the in-situ coal combustion model, and the control model. The turbulence equations are shown below:

[0133]

[0134] in, and μ represents the turbulent kinetic energy and turbulent dissipation rate. t For turbulent viscosity, This represents the amount of turbulent kinetic energy generated due to the velocity gradient. This represents the contribution of wave expansion in compressible turbulence to the overall dissipation rate. and The constant is 1.44 and 1.92 respectively. They are respectively for and The turbulent Prandtl numbers are 1.0 and 1.3, respectively.

[0135] S4606, Solve the component transport equation.

[0136] More specifically, solve the component transport equations in the governing equations based on fluid mechanics.

[0137] S4607, Solve the energy equation.

[0138] More specifically, solve the energy equation in the governing equations based on fluid mechanics.

[0139] S4608, Update coal seam physicochemical parameters.

[0140] More specifically, updating the physicochemical parameters of the coal seam involves solving scalar equations and updating the parameters. By solving the three custom scalar equations in Table 1, parameters reflecting the physicochemical properties of the coal seam are obtained, and the initial parameters and parameters reflecting the physicochemical properties of the coal seam are updated.

[0141] S4609, Check for convergence.

[0142] More specifically, it examines whether the values ​​of the physicochemical properties of the coal seam converge.

[0143] S4610, Exit the loop.

[0144] More specifically, if the physicochemical property parameters of the coal seam do not converge, the calculation is terminated.

[0145] S4611, Continue the loop.

[0146] More specifically, if the values ​​of the coal seam physicochemical properties converge, the next cycle continues, updating the initial values ​​of the coal seam and the parameters of the coal seam physicochemical properties.

[0147] For example, through the model solution process in steps S4601-S4611, the temperature field and concentration field of the coal seam after heating for 1000 s are calculated. The schematic diagram of the temperature distribution of the coal seam and horizontal well after 1000 s of stable combustion of liquid fossil fuel is shown below. Figure 7 As shown, the region with a value of 3.98e+02 has a lower temperature, while the region with a value of 1.56e+03 has a higher temperature. Numerical calculations can predict that the horizontal well temperature is higher than the coal seam temperature. The porosity distribution of the coal seam after 1000 seconds of stable combustion heating with liquid fossil fuel is illustrated in the diagram. Figure 8 As shown, the porosity of the region with a value of 8.29e-02 is relatively low, while the porosity of the region with a value of 8.29e-01 is relatively high. It can be predicted by numerical calculation that the porosity of the coal seam region near the horizontal well is relatively high.

[0148] In the numerical simulation method for in-situ ignition combustion of coal provided in this application embodiment, by setting fuel combustion inlet conditions and in-situ combustion inlet conditions, this method makes it easier to control the coal seam combustion reaction and more adaptable to and simulate various actual operating conditions. By solving the simulation results of in-situ ignition combustion of coal, the initial value parameters and physicochemical property parameters of the coal seam are updated, improving the prediction accuracy. A schematic diagram of the coal seam temperature and porosity distribution is drawn, and the changes and trends of the underground coal seam during the ignition process are predicted more comprehensively and accurately.

[0149] This application provides a numerical simulation device for in-situ ignition combustion of coal. A schematic diagram of the numerical simulation device is shown below. Figure 9 As shown, the numerical simulation apparatus 900 includes:

[0150] Module 901 is used to create a three-dimensional model of the target area and to mesh the three-dimensional model; the target area includes the horizontal well combustion zone and the coal seam reaction zone.

[0151] Module 901 is also used to establish a fuel combustion model of the fuel in the combustion zone based on a three-dimensional model;

[0152] Module 901 is also used to establish an in-situ coal combustion model based on a three-dimensional model when the coal seam reaction zone provides an external heat source in the combustion zone;

[0153] The solver module 902 is used to solve the fuel combustion model and the coal in-situ combustion model to obtain the simulation results of coal in-situ ignition combustion.

[0154] Optionally, the fuel is injected into the combustion zone in an atomized state;

[0155] Module 901 is created, specifically for:

[0156] A discrete phase particle model of the fuel and a combustion reaction model of the fuel were established based on a three-dimensional model.

[0157] Module 901 is created, specifically for:

[0158] Based on the chemical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a moisture evaporation model, a volatile matter separation and desorption model, a fixed carbon combustion model, and a fixed carbon gasification model are established.

[0159] Based on the physical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a control model based on fluid dynamics is established.

[0160] Based on the physical reaction process of the coal seam reaction zone when the combustion zone provides an external heat source, a coal seam cavity evolution model is established.

[0161] Module 901 is created, specifically for:

[0162] It receives the injection parameters of coolant, combustion improver, and fuel, and solves the fuel combustion model based on these parameters to obtain the reactant parameters after fuel combustion.

[0163] The in-situ combustion model of coal is solved based on the reactant parameters after fuel combustion to obtain the simulation results of in-situ ignition combustion of coal.

[0164] like Figure 10 As shown, this application provides an electronic device 1000, which includes a memory 1001 and a processor 1002.

[0165] The memory 1001 is used to store computer instructions that can be executed by the processor;

[0166] When executing computer instructions, the processor 1002 implements each step of the numerical simulation method for in-situ ignition combustion of coal in the above embodiments. For details, please refer to the relevant descriptions in the aforementioned embodiments of the numerical simulation method for in-situ ignition combustion of coal.

[0167] Optionally, the memory 1001 can be either independent or integrated with the processor 1002. When the memory 1001 is configured independently, the electronic device also includes a bus for connecting the memory 1001 and the processor 1002.

[0168] This application also provides a computer-readable storage medium storing computer instructions. When a processor executes the computer instructions, it implements the various steps in the numerical simulation method for in-situ ignition combustion of coal described in the above embodiments.

[0169] This application also provides a computer program product, including computer instructions, which, when executed by a processor, implement various steps in the numerical simulation method for in-situ ignition combustion of coal described in the above embodiments.

[0170] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0171] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

[0172] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

Claims

1. A numerical simulation method for in-situ ignition combustion of coal, characterized in that, include: A three-dimensional model of the target area is established, and the three-dimensional model is meshed; wherein, the target area includes the horizontal well combustion zone and the coal seam reaction zone; A fuel combustion model for the fuel in the horizontal well combustion zone is established based on the three-dimensional model. Based on the three-dimensional model, an in-situ combustion model of coal is established when the coal seam reaction zone provides an external heat source to the horizontal well combustion zone. The system receives injection parameters for coolant, combustion improver, and fuel, and solves the fuel combustion model based on these parameters to obtain the reactant parameters after fuel combustion. The in-situ combustion model of coal is solved based on the reactant parameters after the fuel combustion to obtain the simulation results of in-situ ignition combustion of coal.

2. The numerical simulation method according to claim 1, characterized in that, in, The fuel is injected into the horizontal well combustion zone in an atomized state; Based on the aforementioned three-dimensional model, a fuel combustion model for the fuel within the horizontal well combustion zone is established, specifically including: Based on the three-dimensional model, a discrete phase particle model of the fuel and a combustion reaction model of the fuel are established; the fuel combustion model includes the discrete phase particle model and the combustion reaction model of the fuel.

3. The numerical simulation method according to claim 1 or 2, characterized in that, Based on the aforementioned three-dimensional model, an in-situ combustion model of coal is established when the coal seam reaction zone provides an external heat source to the horizontal well combustion zone. Specifically, this includes: Based on the chemical reaction process of the coal seam reaction zone when it provides an external heat source to the horizontal well combustion zone, a moisture evaporation model, a volatile matter separation and desorption model, a volatile matter combustion model, and a fixed carbon combustion gasification model are established. Based on the physical reaction process of the coal seam reaction zone when it provides an external heat source to the horizontal well combustion zone, a control model based on fluid dynamics is established. Based on the physical reaction process of the coal seam reaction zone when it provides an external heat source to the combustion zone of the horizontal well, a coal seam cavity evolution model is established.

4. A numerical simulation device for in-situ ignition combustion of coal, characterized in that, include: A module is established to create a three-dimensional model of the target area and to mesh the three-dimensional model; wherein, the target area includes the horizontal well combustion zone and the coal seam reaction zone; The establishment module is also used to establish a fuel combustion model of the fuel in the horizontal well combustion zone based on the three-dimensional model; The establishment module is also used to establish an in-situ coal combustion model based on the three-dimensional model when the coal seam reaction zone provides an external heat source in the horizontal well combustion zone; The solver module is used to solve the fuel combustion model and the coal in-situ combustion model to obtain the simulation results of coal in-situ ignition combustion. The establishment module is specifically used to: receive the injection parameters of coolant, the injection parameters of combustion accelerator and the injection parameters of fuel, and solve the fuel combustion model according to the injection parameters of coolant, the injection parameters of combustion accelerator and the injection parameters of fuel to obtain the reactant parameters after fuel combustion. The in-situ combustion model of coal is solved based on the reactant parameters after the fuel combustion to obtain the simulation results of in-situ ignition combustion of coal.

5. The numerical simulation apparatus according to claim 4, characterized in that, in, The fuel is injected into the combustion zone in an atomized state; The establishment module is specifically used for: Based on the three-dimensional model, a discrete phase particle model of the fuel and a combustion reaction model of the fuel are established; the fuel combustion model includes the discrete phase particle model and the combustion reaction model of the fuel.

6. The numerical simulation apparatus according to claim 4 or 5, characterized in that, The establishment module is specifically used for: Based on the chemical reaction process of the coal seam reaction zone when the external heat source is provided in the horizontal well combustion zone, a moisture evaporation model, a volatile matter separation and desorption model, a fixed carbon combustion model, and a fixed carbon gasification model are established. Based on the physical reaction process of the coal seam reaction zone when it provides an external heat source to the horizontal well combustion zone, a control model based on fluid dynamics is established. Based on the physical reaction process of the coal seam reaction zone when it provides an external heat source to the combustion zone of the horizontal well, a coal seam cavity evolution model is established.

7. An electronic device, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the method as described in any one of claims 1 to 3.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1 to 3.

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