Numerical Model Construction Method for Simulating Body Combustion Using Organic Matter Decomposition

Abstract

This application discloses a method for constructing a numerical model to simulate the combustion of remains using the decomposition of organic matter, relating to the field of computer simulation technology. The method includes obtaining the proportions of biological components and hydrocarbon substitute components input by the user through an interface. These proportions are determined by heterogeneous combustion reaction experiments, thermal decomposition experiments, and oxygen bomb calorimetry experiments of organic matter. The biological components include total moisture, volatile matter, and ash, while hydrocarbon substitutes are used to replace the volatile matter. A cremation model is established based on these proportions. After dividing the cremation model into a grid, the grid area is discretized and combustion simulation is performed using governing equations to obtain the temperature field data corresponding to the cremation model. The numerical model construction method of this application can simulate the combustion process of remains, facilitating subsequent upgrades and optimization designs of crematoriums.

Description

Technical Field

[0001] This application relates to the field of computer simulation technology, and in particular to a method for constructing a numerical model that uses the decomposition of organic matter to simulate the burning of remains. Background Technology

[0002] Crematoriums are key facilities in the modern funeral service system, used for the high-temperature incineration of remains. However, due to ethical constraints, the design of related technologies has focused primarily on furnace structure and operating conditions, with a lack of research on heating remains inside the furnace. This has significantly hampered the subsequent optimization of crematoriums. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies in related technologies, it is desirable to provide a method for constructing a numerical model to simulate the combustion of remains by utilizing the decomposition of organic matter. This method can simulate the combustion process of remains and provide guidance for the subsequent upgrade and optimization design of crematoriums.

[0004] This application provides a method for constructing a numerical model to simulate the combustion of remains using the decomposition of organic matter. The method includes:

[0005] The proportion of biological components and the proportion of hydrocarbon and oxygen substitute components are obtained by the user through the operation interface. The proportion of biological components and the proportion of hydrocarbon and oxygen substitute components are determined by heterogeneous combustion reaction experiment, thermal decomposition experiment and oxygen bomb calorimetry experiment of organic matter. The biological components include total moisture, volatile matter and ash, and hydrocarbon and oxygen substitutes are used to replace the volatile matter.

[0006] A cremation model for the remains was established based on the proportions of the biological components and the proportions of the carbon, hydrogen, and oxygen substitute components. After dividing the cremation model into a grid, the grid area was discretized and combustion simulation was performed using the governing equations to obtain the temperature field data corresponding to the cremation model.

[0007] Optionally, in some embodiments of this application, the organic matter is lean pork or pork fat, where lean pork represents protein and pork fat represents fat.

[0008] Optionally, in some embodiments of this application, the total moisture content includes free water, moisture in the lean pork, and moisture in the pork fat.

[0009] Optionally, in some embodiments of this application, the volatile components include combustible components in the lean pork other than moisture and combustible components in the fat pork other than moisture.

[0010] Optionally, in some embodiments of this application, the hydrocarbon substitutes are mixtures of CH4, CO, and H2.

[0011] Optionally, in some embodiments of this application, the calorific value of the sample in the oxygen bomb calorimetry experiment is determined by the following formula:

[0012] ;

[0013] In the above formula, This indicates the calorific value of the sample, expressed in J / g. This indicates the heat capacity of the calorimetric system, expressed in kJ / ℃. Indicates the initial temperature of the main period. This indicates the end temperature of the main period, in Kelvin (K). This indicates the time interval between ignition and the end of the firing cycle, including the temperature range. It is a positive integer. Indicates the cooling correction value; This indicates the heat generated by the ignition wire. The heat generated by additives other than the ignition wire is expressed in kJ. This indicates the mass of the sample, expressed in kg.

[0014] Optionally, in some embodiments of this application, the cooling correction value is determined by the following formula:

[0015] ;

[0016] In the above formula, This indicates the number of half-minute intervals during the main period where the temperature rises by at least 0.3 K per half-minute. Indicates the initial rate of temperature change. , Indicates the initial temperature. Indicates the rate of temperature change at the end of the period. , This indicates the final temperature, and the unit is K.

[0017] Optionally, in some embodiments of this application, the reaction of nozzle fuel combustion in the cremation model is based on the methane-air-2step model, the in-furnace radiation is based on the P1 model, and the boundary conditions are set based on convection and radiation.

[0018] Optionally, in some embodiments of this application, the turbulence model in the governing equations adopts the Realizable k-ε model.

[0019] Optionally, in some embodiments of this application, the energy source term in the energy conservation equation of the governing equation is the sum of the heat of reaction and the heat of matter, wherein the heat of reaction is determined based on the heat of reaction of volatiles and the latent heat of vaporization of water, and the heat of matter is determined based on the total specific heat of volatiles and the specific heat of water.

[0020] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0021] This application provides a method for constructing a numerical model to simulate the combustion of remains using the decomposition of organic matter. The biological components of the remains are simplified into three parts: total moisture, volatile matter, and ash. Carbon, hydrogen, and oxygen substitutes are used to replace the volatile matter. The proportions of biological components and carbon, hydrogen, and oxygen substitutes are determined through heterogeneous combustion reaction experiments, thermal decomposition experiments, and oxygen bomb calorimetry experiments of organic matter. Thus, a cremation model can be established based on the proportions of biological components and carbon, hydrogen, and oxygen substitutes. After the cremation model is divided into grids, the grid area can be discretized and combustion simulated using governing equations to obtain the temperature field data corresponding to the cremation model. Test verification shows that the simplified biological components and the combustion of carbon, hydrogen, and oxygen substitutes are consistent with reality and can provide guidance for the subsequent upgrade and optimization design of crematoriums. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A flowchart illustrating a method for constructing a numerical model to simulate the combustion of remains using the decomposition of organic matter, provided in an embodiment of this application;

[0024] Figure 2 A schematic diagram of a cremation model provided in this application embodiment;

[0025] Figure 3 A temperature field distribution cloud map inside the furnace during a simulation process is provided for an embodiment of this application;

[0026] Figure 4 This application provides a schematic diagram of an experiment using an infrared imager for temperature measurement.

[0027] Figure 5 A schematic diagram showing the comparison between experimental and simulated flue gas temperatures provided in an embodiment of this application;

[0028] Figure 6 A structural block diagram of a numerical model construction device for simulating the combustion of remains by decomposing organic matter, provided in an embodiment of this application;

[0029] Figure 7 This is a structural block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The following examples illustrate this. Figures 1 to 7 This application provides a detailed description of the method for constructing a numerical model that simulates the combustion of remains by utilizing the decomposition of organic matter, as provided in the embodiments of this application.

[0033] Please refer to Figure 1 This is a flowchart illustrating a method for constructing a numerical model to simulate the combustion of remains using the decomposition of organic matter, as provided in an embodiment of this application. The method specifically includes the following steps:

[0034] S101, obtain the proportion of biological components and the proportion of hydrocarbon and oxygen substitute components input by the user through the operation interface. The proportion of biological components and the proportion of hydrocarbon and oxygen substitute components are determined by heterogeneous combustion reaction experiment, thermal decomposition experiment and oxygen bomb calorimetry experiment of organic matter. Among them, biological components include total moisture, volatile matter and ash, and hydrocarbon and oxygen substitutes are used to replace volatile matter.

[0035] It should be noted that, based on the content of human body composition in the "Encyclopedia of Chinese Nutritional Science," the human body composition is simplified according to the 4C model, which includes four parts: water, protein, fat, and bone. As shown in Table 1, which lists the body fat percentage ranges for different age groups and body types, the embodiments in this application use a gradient setting of body fat percentages from 10% to 30%, as shown in Table 2. This range is consistent with the average body fat percentage and has universal applicability.

[0036] Table 1. Body fat percentage ranges for different body types in different age groups.

[0037]

[0038] Table 2. Gradient settings for body fat percentage

[0039]

[0040] Furthermore, in determining the proportions of biological components and carbon, hydrogen, and oxygen substitutes, the organic matter in this application embodiment is either lean pork or pork fat, i.e., lean pork represents protein and pork fat represents fat. During the experiment, common commercially available breeds of pork were selected to ensure universality, and standardized processing was performed. All samples were taken from several pigs raised in the same environment and with the same feed formula to avoid interference with component data due to metabolic differences. Pig breeds included, but not limited to, Landrace pigs (high lean meat percentage, well-developed muscles, suitable for extracting typical lean meat samples), Duroc pigs (strong fat deposition performance, suitable for extracting typical fat samples), and Large White pigs (robust bones, high bone density). The lean meat (mainly protein) was sampled from areas with high muscle fiber density and low connective tissue, such as the tenderloin and hind legs. The fat (mainly fat) was sampled from areas with significant fat accumulation, such as backfat and back fat. The pig bones (mainly ash) were sampled from bones with high mineral content, such as the femur, tibia, and vertebrae.

[0041] In the heterogeneous combustion reaction experiment, air was used as the atmosphere. Heterogeneous materials of different tissues (high-fat fatty meat, high-protein lean meat) were placed into the crucible of a thermogravimetric analyzer. The same air flow rate (30 ml / min) was set, and the reaction temperature was used as the variable. The flue gas (H2S, SO2) was detected by a flue gas analyzer. The volatile organic compound (VOC) components generated at different temperatures were detected by gas chromatography. The influence of combustion conditions (such as different combustion temperatures) on the release pattern of VOCs generated by the combustion of biomass raw materials and their components was analyzed. The source of VOCs was determined according to the different components. Since the main components of the remains are water, protein, fat, and inorganic salts, with inorganic salts being relatively low in content and having little impact on heat and mass transfer during combustion, they are not considered. Therefore, in the pyrolysis experiment, appropriate samples of lean or fatty pork were taken, their surface moisture was wiped dry with absorbent paper, and they were placed in an alumina crucible. The temperature was increased from 20°C to 900°C at different heating rates (5°C / min, 10°C / min). To ensure a suitable pyrolysis atmosphere, high-purity nitrogen was used as the carrier gas at a flow rate of 50 ml / min. The pyrolysis characteristics of the remains were reflected by studying the pyrolysis process of lean and fatty pork. Measurements showed that the water content of lean pork was 63.83%, and that of fatty pork was 20.93%. The weight loss rate of both lean and fatty pork was close to 100%. Therefore, the composition of lean and fatty pork was simplified to water and combustible components. Assuming that ash does not participate in the heat change, then... =1, ·63.83% ·20.93%, ·36.17% 79.07%, The total moisture content represents the mass fraction, which includes free water, water in lean pork, and water in pork fat. Volatile matter includes combustible components in lean pork other than water and combustible components in pork fat other than water. The human body typically contains 50% to 70% water. For example, if the bone mass (ash content) is taken as 5%, the corresponding five groups of total moisture content can be set in a gradient of 58% to 74% (as shown in Table 3).

[0042] Table 3. Gradient setting of total moisture

[0043]

[0044] For example, if the total water content is taken as 70%, and combined with Table 2, the body fat percentage is taken as 15%, then the corresponding relationship of the 4C model to the 3C model is shown in Table 4, that is, the proportion of biological components can be 70% total water content, 25% volatile matter content, and 5% ash content.

[0045] Table 4. Model Transformation Correspondence

[0046]

[0047] Furthermore, in the oxygen bomb calorimetry experiment, the same lean and fatty pork samples used in the thermal decomposition experiment were employed. First, an appropriate amount of the sample was weighed using an electronic balance and dried in an 80℃ drying oven for 24 hours. Second, the dried sample was pressed into a cake (if it is fatty pork, pressing is unnecessary), weighed, and its mass (usually 1-1.5g) was recorded. The sample was then placed in the combustion dish of the oxygen bomb calorimeter. Third, a section of ignition wire was taken, its length L0 was measured, and the two ends of the ignition wire were connected to the two electrodes of the oxygen bomb. The oxygen bomb was tightened, and oxygen was introduced into it, maintaining a pressure of 2-2.5 MPa. The airtightness of the oxygen bomb was checked. Finally, 3 liters of water that had been left to stand at room temperature for a long time were placed in the inner cylinder, and the oxygen bomb was submerged in the water. The stirrer, thermometer, ignition wire, and power supply were installed, and the outer cylinder cover was closed. The stirrer was then turned on. The sample combustion mainly consisted of three stages. In the initial stage, the thermometer reading stabilized, and the initial temperature was recorded. Ignition is initiated by powering on the device. During the main phase, the thermometer reading is recorded every minute until the temperature begins to drop from its highest point. Temperature is recorded several more times at the end of the phase. After the main phase, stirring is stopped, the oxygen bomb is removed, the pressure is released, and the bomb holder is opened. The reaction of the substances in the combustion vessel is observed to determine if the reaction is complete, and the remaining length L1 of the ignition wire is measured.

[0048] The oxygen bomb calorimetry experiment involves placing a known amount of fuel in a sealed container (oxygen bomb), filling it with oxygen, igniting it to achieve complete combustion, and transferring the heat released by combustion to the surrounding water. The calorific value of the fuel is then calculated based on the water's temperature rise.

[0049] (1)

[0050] In equation (1), This indicates the calorific value of the sample, expressed in J / g. It represents the heat capacity of the calorimetric system, with the unit being kJ / ℃. It is the amount of heat that the entire calorimetric system (including the inner cylinder water, oxygen bomb, stirrer, thermometer probe, etc.) needs to absorb to increase the temperature by 1℃. This represents the corrected true temperature rise, indicating the adjusted temperature increase caused by sample combustion. Indicates the initial temperature of the main period. This indicates the end temperature of the main period, in Kelvin (K). This indicates the time interval between ignition and the end of the firing cycle, including the temperature range. It is a positive integer. Indicates the cooling correction value; This represents the total heat released by the ignition wire and additives; it is a correction term for the heat generated by combustion of non-sample components. This indicates the heat generated by the ignition wire. This indicates the heat generated by additives other than the ignition wire, such as ignition cotton thread and paraffin oil, and is expressed in kJ. This indicates the mass of the sample, expressed in kg.

[0051] For example, cooling correction value Determined by equation (2):

[0052] (2)

[0053] In equation (2), This indicates the number of half-minute intervals in the main period where the temperature rises by at least 0.3 K every half-minute. The first interval is counted regardless of the magnitude of the temperature rise. value; Indicates the initial rate of temperature change. , Indicates the initial temperature. Indicates the rate of temperature change at the end of the period. , The values ​​represent the final temperature, all in Kelvin. The calculated calorific value of lean pork was 20.39 MJ / kg, and that of pork fat was 38.00 MJ / kg. This data is within 1% of the measured calorific values ​​of human protein (20.63 MJ / kg) and human fat (38.33 MJ / kg) in the literature, verifying the accuracy of the experimental results. The latent heat of vaporization of water is 2.2564 MJ / kg. ·20.39 ·38.00 ·2.2564= · 2.2564 .

[0054] Furthermore, specific substitutes for volatile matter in the 3C model are defined, namely, the calorific value of the combustible part is first calculated, as shown in Table 5.

[0055] Table 5 Combustible calorific value

[0056]

[0057] Then, based on their calorific values, the combustible components are simplified into a mixture of hydrocarbon substitutes CH4, CO, and H2, as shown in Table 6. This setup is advantageous because it aligns with the subsequent use of natural gas as fuel, facilitating rapid simulation. The calorific value of CH4 is 55.5 MJ / kg, CO is 10.1 MJ / kg, and H2 is 120.0 MJ / kg. Furthermore, the combustion of combustible components involves two stages: macromolecular decomposition and small-molecule combustion. Therefore, the experimentally measured calorific values ​​of lean and fatty pork are the sum of the heats of reaction from both stages. However, in this embodiment, the calorific values ​​of lean and fatty pork are directly equivalent to the calorific values ​​of mixtures of different proportions of small molecules, meaning that the heat of reaction from the macromolecular decomposition stage is considered zero. For example, the proportions of CH4, CO, and H2 in the hydrocarbon substitute components can be 40%, 14%, and 46%, respectively.

[0058] Table 6. Proportion of volatile matter substitute components

[0059]

[0060] S102, a cremation model for remains was established based on the proportion of biological components and the proportion of carbon, hydrogen and oxygen substitute components. After dividing the cremation model into grids, the grid area was discretized and combustion simulation was performed using the governing equations to obtain the temperature field data corresponding to the cremation model.

[0061] In this embodiment of the application, when establishing the cremation model, the height, weight, and furnace dimensions of the remains can be set. For example, if the height of the remains is 170cm and the weight is 70kg, the furnace dimensions are length × width × height = 2200mm × 700mm × 832.5mm. This means that based on the height and weight of the remains, combined with the proportions of biological components and hydrocarbon substitute components, the mass of biological components and hydrocarbon substitute components corresponding to that height and weight can be obtained and uniformly distributed in the cremation model. Of course, some embodiments of this application can also use a stepped distribution based on different parts of the remains.

[0062] For example, with Figure 2Taking the established model as an example, the proportions of total moisture in the biological components are selected as 70%, volatile matter as 25%, and ash as 5%. In the hydrocarbon substitute component ratios, CH4 is selected as 40%, CO as 14%, and H2 as 46%. The processing and verification of data for other groups are similar. The nozzle fuel combustion reaction in the cremation model adopts the methane-air-2step model, which represents the first incomplete reaction of CH4 and O2 to produce CO and H2O, and the oxidation of CO to CO2. The diesel model corresponds to the diesel-air model, typically using No. 0 diesel, but n-decane is used as a substitute during the simulation, i.e., C... 10 H 22 The diesel fuel reacts with O2, and an intermediate reaction involving incomplete combustion to produce CO is added. The diesel fuel is injected into the combustion chamber through a nozzle using a discrete phase model. The turbulent-chemical reaction mechanism is based on the Eddy-Dissipation model, which facilitates the occurrence and rapid development of the combustion reaction. Since the furnace temperature is typically around 800–1200 °C, the radiative heat transfer within the furnace cannot be ignored; therefore, the P1 model is chosen as the radiation model.

[0063] The fuel gun inlet contains an air-fuel mixture at room temperature, while the secondary air inlet contains only air at 200℃. The excess air coefficient in the air supply settings is 1.55. Referring to the final fuel consumption target of 12 kg / body and a body weight of 70 kg, corresponding to a burning time of 40 minutes per body, the total air supply volume is 1.55 × (11.19 × 12 + 2.107 × 70) = 436.7435 m³. 3 The total air supply flow rate is 436.7435 / (40 × 60) = 0.182 m³. 3 / s. The air supply consists of three parts: primary air (oil gun air), secondary air (side air and top air). Based on field operation experience, the proportions are as follows: primary air constitutes the majority, side air is supplied after ignition, and top air supply is very small. Considering the relatively large area of ​​the side air outlet and the difficulty in ignition simulation if the primary air velocity is too high, the proportion of primary air is set at 1%, the total proportion of side air is 95%, and the total proportion of top air is 4%. It is 2.574 m / s. It is 19.656 m / s. The velocity is 5.793 m / s, corresponding to the inlet boundary condition settings for each velocity in the Fluent simulation. The primary air is unpreheated, i.e., the inlet temperature is 300 K, while the secondary air is preheated, corresponding to a preheating temperature of 473 K. The composition percentage for both is 21% O2 + 79% N2 by volume. The inlet turbulence settings are turbulence intensity and hydraulic diameter, with turbulence intensity set to 10% and hydraulic diameter determined by the inlet size: 57.5 mm for the primary air inlet and 20 mm for the secondary air inlet.

[0064] Alternatively, natural gas can be used as fuel. Referring to the diesel fuel index of 12 kg / unit, the natural gas supply should be selected based on the same calorific value of 514,800 kJ / unit. The calorific value of natural gas is 37.62 MJ / m³. 3 Therefore, the natural gas supply is selected as 514800 / (37.62 × 1000) = 13.684 m³. 3 This corresponds to a combustion time of 40 minutes per unit, meaning a natural gas flow rate of 0.0058 m³. 3 / s. The primary air in the premixed gas at the nozzle is distributed with an air coefficient of 1 corresponding to the natural gas flow rate. Natural gas follows a CH4 reaction with a twice-to-oxygen ratio, therefore the mixture composition is 9.5% CH4 + 19% O2 + 71.5% N2. Converting the CH4 flow rate to the mixed gas flow rate gives 0.0058 / 0.095 = 0.061 m³ / s. 3 The oil gun inlet inner diameter is 57.5 mm, so the volumetric flow rate converted to the mixed gas velocity is 0.061 / (3.14×0.0575×0.0575 / 4) = 23.5 m / s. The primary air volume in this part is 198.738 m³ / s. 3 / h. The total air supply to the boiler is based on an air coefficient of 1.5 corresponding to the natural gas volume. After deducting the primary air, the remainder is supplied by the side and top air in the secondary air supply, with a natural gas supply of 13.684 m³. 3 Therefore, the total air demand is (13.684 × 2 × 1.5) / 0.21 = 195.486 m³. 3 / tool=293.228m 3 / h, therefore the total secondary wind is 293.228 - 198.738 = 94.49 m. 3 / h=0.0262 m 3 / s, there are 4×7=28 holes for crosswinds and 2×3=6 holes for topwinds, all with an inner diameter of 20mm. Crosswinds account for 95% and topwinds account for 5%. Therefore, the crosswind velocity is 0.0262×0.95 / 28 / (3.14×0.01×0.01)=2.831m / s, and the topwind velocity is 0.0262×0.05 / 6 / (3.14×0.01×0.01)=0.695 m / s. Additionally, the sidewall material of the cremator is solid clay brick (density 2000 kg / m³). 3 The thermal conductivity is 0.5 W / (kg·K), and the specific heat is 1.05 kJ / (kg·K). The corresponding materials for the furnace roof, kang surface, and flue are solid concrete bricks (density 1800 kg / m³). 3The thermal conductivity is 1.0 W / (kg·K), the specific heat is 1.05 kJ / (kg·K), the furnace top wall thickness is 115 mm, the side wall thickness is 115 mm, and the thickness of the kang surface and flue is 65 mm (all based on the thickness of one brick). The boundary conditions use a mixed type, which refers to the mixed method in the Fluent settings, i.e., settings based on convection and radiation, adding external 300K air convection, and an internal convection coefficient of 0.44 W / m. 2 The original internal radiation coefficient is 0.5, but it becomes 0.9 if a radiation-enhancing coating is added.

[0065] The governing equations include the mass conservation equation, momentum conservation equation, energy conservation equation, and turbulence model. The turbulence model employs the Realizable k-ε model for more accurate calculations. The mass source term in the mass conservation equation is the sum of the moisture source term, the volatile matter source term, and the ash content, with the ash mass being a fixed value. The energy source term in the energy conservation equation is the sum of the heat of reaction and the heat of matter. This heat of reaction is determined based on the heat of reaction of volatile matter and the latent heat of vaporization of moisture; that is, heat of reaction = volatile matter source term. Heat of reaction of volatiles - moisture source item The latent heat of vaporization of water is determined based on the total specific heat of volatiles and the specific heat of water, i.e., heat of vaporization = (vaporization source term) / (vaporization source term) Total specific heat of volatile matter + moisture source item (Specific heat of water) (Volume mesh temperature - ambient temperature). Moisture and volatile matter source terms are added using source term functions in the UDF file. Their release rates are determined by the Arrhenius equation. For the moisture source term, when the volume mesh temperature is greater than 100°C, the release rate is... a = A exp(- B / ( R T )), A Indicates the exponential factor. B Indicates the activation energy of the reaction. R These three numbers represent the gas constants; they are all definite constants. T The volumetric mesh temperature is represented, therefore the release rate is a function of temperature; when the volumetric mesh temperature is less than 100℃, the release rate is 0. Similarly, the principle of the volatile matter source term is similar, but the initial judgment temperature is 200℃.

[0066] For the combustion zone of the remains, which contains solid incinerators, pyrolysis products of solid incinerators, and air, a porous media model is needed to describe it. The thermal conductivity, mass of incinerators, and other physical properties of the porous region are described using porosity. The energy conservation equation for this combustion zone is:

[0067] (3)

[0068] In equation (3), Indicates time, in seconds; Porosity represents the volume fraction of fluid in a porous medium. This indicates the fluid density in the combustion zone of the remains, including the density of the mixed flue gas containing pyrolysis products, incineration products, and air, expressed in kg / m³. 3 ; This refers to the energy contained in a unit mass of fluid within the combustion zone of the remains, including enthalpy, pressure energy, and kinetic energy. This refers to the density of solids in the combustion zone of the remains, also known as the density of the remains domain, and is expressed in kg / m³. 3 ; This refers to the energy contained per unit mass of solid within the combustion zone of the remains, primarily referring to the internal energy of the solid. This represents a velocity vector, with units of m / s; This indicates pressure, expressed in Pa. This represents the effective thermal conductivity of the fluid, expressed in W / m·K. This indicates the volume grid temperature, in Kelvin (K). Indicates biological components The enthalpy value, in J; Indicates biological components The diffusion flux, described by Fick's law, is expressed in kg / (m³). 2 ·s); This represents the effective stress tensor, with units of N / m. 2 ; This represents the energy source term, with units of W / m³. 3 .

[0069] In addition, the SIMPLE model was selected for the calculation. To improve the accuracy of the calculation, except for the first-order upwind discrete equations for turbulent kinetic energy and dissipation rate, the second-order upwind discrete equations were selected for the calculation of pressure, kinetic energy, energy, and each component. The relaxation factor was kept at the default setting. Except for the energy equation residual of 1e-6, the calculation residual was adjusted to 1e-4. The temperature field distribution cloud map inside the furnace during the simulation is shown in the figure. Figure 3 As shown, Figure 3 for Figure 2 The view from the back.

[0070] Furthermore, experimental data and simulated data from a funeral home in a certain province with similar mortuary conditions were compared and verified. The comparison of the furnace temperature field is shown in Table 7. To facilitate the acquisition of experimental data, in Figure 4 The figure in Figure (a) shows an infrared imager installed on the side of the oil gun to record the temperature field inside the furnace in real time. Figure 4Figure (b) shows the temperature distribution histogram over time. Table 7 also contains data from infrared measurements taken during the stable combustion phase in the later stages of cremation. Table 7 shows that the simulated temperature field error is within 10%, conforming to the pattern of front > middle > rear along the length direction. Furthermore, the simulated temperature field is slightly higher than the experimental values ​​overall. This is because the simulation is closer to an ideal level, especially with heat loss, such as from the furnace wall, simplified to a very small extent. Figure 4 It can be seen that the high-temperature zone inside the furnace is concentrated at the top and the oil gun, basically maintained at a level of 900℃~1100℃. The high-temperature zone at the top of the furnace is particularly prominent, and it is used to heat the remains. The oil gun is the flame zone, and the left and right rear are the exhaust ports, with the flue gas temperature basically maintained at a level of 650℃~800℃. Figure 5 The comparison of flue gas temperatures shown indicates that the simulation results match the experimental data well, and the overall trend is one of steady increase.

[0071] Table 7 Comparison of furnace temperature fields

[0072]

[0073] The numerical model construction method for simulating the combustion of remains using organic matter decomposition provided in this application simplifies the biological components of remains into three parts: total moisture, volatile matter, and ash. Carbon, hydrogen, and oxygen substitutes are used to replace the volatile matter. The proportions of biological components and carbon, hydrogen, and oxygen substitutes are determined through heterogeneous combustion reaction experiments, thermal decomposition experiments, and oxygen bomb calorimetry experiments of organic matter. Therefore, a cremation model can be established based on the proportions of biological components and carbon, hydrogen, and oxygen substitutes. After the cremation model is meshed, the mesh area can be discretized and combustion simulated using governing equations to obtain the corresponding temperature field data. Tests and verifications show that the simplified biological components and the combustion of carbon, hydrogen, and oxygen substitutes closely resemble reality, providing guidance for the subsequent upgrade and optimization design of crematoriums.

[0074] Based on the foregoing embodiments, this application provides a numerical model construction apparatus for simulating the combustion of remains using the decomposition of organic matter. This numerical model construction apparatus can be used for... Figures 1 to 5 The numerical model construction method corresponding to the embodiment. Please refer to... Figure 6 This is a structural block diagram of a numerical model construction device for simulating the combustion of remains using the decomposition of organic matter, provided in an embodiment of this application. The numerical model construction device 100 includes:

[0075] The acquisition module 101 is used to acquire the proportion of biological components and the proportion of carbon, hydrogen and oxygen substitute components input by the user through the operation interface. The proportion of biological components and the proportion of carbon, hydrogen and oxygen substitute components are determined by heterogeneous combustion reaction experiment, thermal decomposition experiment and oxygen bomb calorimetry experiment of organic matter. The biological components include total moisture, volatile matter and ash, and carbon, hydrogen and oxygen substitutes are used to replace volatile matter.

[0076] The simulation module 102 is used to establish a cremation model of remains based on the proportion of biological components and the proportion of carbon, hydrogen and oxygen substitute components. After dividing the cremation model into grids, the grid area is discretized and combustion is simulated using the governing equations to obtain the temperature field data corresponding to the cremation model.

[0077] Optionally, in the embodiments of this application, the organic matter is lean pork or pork fat, with lean pork representing protein and pork fat representing fat.

[0078] Optionally, in the embodiments of this application, the total moisture includes free water, moisture in lean pork, and moisture in pork fat.

[0079] Optionally, in the embodiments of this application, the volatile components include combustible components in lean pork other than moisture and combustible components in pork fat other than moisture.

[0080] Optionally, in the embodiments of this application, the hydrocarbon substitutes are a mixture of CH4, CO and H2.

[0081] Optionally, in the embodiments of this application, the calorific value of the sample in the oxygen bomb calorimetry experiment is determined by the following formula:

[0082] ;

[0083] In the above formula, This indicates the calorific value of the sample, expressed in J / g. This indicates the heat capacity of the calorimetric system, expressed in kJ / ℃. Indicates the initial temperature of the main period. This indicates the end temperature of the main period, in Kelvin (K). This indicates the time interval between ignition and the end of the firing cycle, including the temperature range. It is a positive integer. Indicates the cooling correction value; This indicates the heat generated by the ignition wire. The heat generated by additives other than the ignition wire is expressed in kJ. This indicates the mass of the sample, expressed in kg.

[0084] Optionally, in the embodiments of this application, the cooling correction value is determined by the following formula:

[0085] ;

[0086] In the above formula, This indicates the number of half-minute intervals during the main period where the temperature rises by at least 0.3 K per half-minute. Indicates the initial rate of temperature change. , Indicates the initial temperature. Indicates the rate of temperature change at the end of the period. , This indicates the final temperature, and the unit is K.

[0087] Optionally, in the cremation model of the remains in this application embodiment, the reaction of nozzle fuel combustion adopts the methane-air-2step model, the radiation in the furnace adopts the P1 model, and the boundary conditions are set based on convection and radiation.

[0088] Optionally, the turbulence model in the control equations of this application embodiment adopts the Realizabled k-ε model.

[0089] Optionally, in the governing equations of this application, the energy source term of the energy conservation equation is the sum of the heat of reaction and the heat of matter, wherein the heat of reaction is determined based on the heat of reaction of volatiles and the latent heat of vaporization of water, and the heat of matter is determined based on the total specific heat of volatiles and the specific heat of water.

[0090] It should be noted that the descriptions of the same steps and contents as in other embodiments in this embodiment can be found in the descriptions in other embodiments, and will not be repeated here.

[0091] In another aspect, embodiments of this application provide an electronic device. Please refer to... Figure 7 The electronic device 200 may include a processor 201 and a memory 202. The memory 202 stores at least one instruction, at least one program, code set, or instruction set, which is loaded and executed by the processor 201 to implement [the desired functionality]. Figures 1 to 5 The steps of the model construction method in the corresponding embodiment.

[0092] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0093] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed between each other can be through some interfaces, indirect coupling or communication connection between devices or modules, and can be electrical, mechanical, or other forms. Modules described as separate components may or may not be physically separate, and components shown as modules may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0094] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each module can exist physically separately, or two or more units can be integrated into one module. The integrated unit can be implemented in hardware or as a software functional unit. If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0095] Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the numerical model construction method of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for constructing a numerical model to simulate the combustion of remains using the decomposition of organic matter, characterized in that, The numerical model construction method includes: The proportion of biological components and the proportion of hydrocarbon substitute components are obtained by the user through the operation interface. The proportion of biological components and the proportion of hydrocarbon substitute components are determined by heterogeneous combustion reaction experiment, thermal decomposition experiment and oxygen bomb calorimetry experiment of organic matter. The biological components include total moisture, volatile matter and ash. The hydrocarbon substitutes are used to replace the volatile matter. According to the calorific value, the combustible part is simplified to a mixture of hydrocarbon substitutes CH4, CO and H2. The combustion of combustible part is divided into two stages: macromolecular pyrolysis and small molecule combustion. The reaction heat of the macromolecular pyrolysis stage is regarded as zero. A cremation model for the remains was established based on the proportion of biological components and the proportion of carbon, hydrogen and oxygen substitute components. After dividing the cremation model into a grid, the grid area was discretized and combustion simulation was performed using the governing equations to obtain the temperature field data corresponding to the cremation model. The governing equations include the mass conservation equation, momentum conservation equation, energy conservation equation, and turbulence model. The energy source term in the energy conservation equation is the sum of the heat of reaction and the heat of matter. The heat of reaction is determined based on the heat of reaction of volatiles and the latent heat of vaporization of water; therefore, the heat of reaction equals the volatiles source term. Heat of reaction of volatiles - moisture source item The latent heat of vaporization of water, the heat of substance is determined based on the total specific heat of volatiles and the specific heat of water, heat of substance = (volatiles source term) Total specific heat of volatile matter + moisture source item (Specific heat of water) (Volume grid temperature - ambient temperature); The energy conservation equation for the combustion zone of the remains is: ； In the above formula, Indicates time, in seconds; Porosity represents the volume fraction of fluid in a porous medium. This indicates the fluid density in the combustion zone of the remains, including the density of the mixed flue gas containing pyrolysis products, incineration products, and air, expressed in kg / m³. 3 ; This refers to the energy contained in a unit mass of fluid within the combustion zone of the remains, including enthalpy, pressure energy, and kinetic energy. This refers to the density of solids in the combustion zone of the remains, also known as the density of the remains domain, and is expressed in kg / m³. 3 ; This refers to the energy contained per unit mass of solid within the combustion zone of the remains, primarily referring to the internal energy of the solid. This represents a velocity vector, with units of m / s; This indicates pressure, expressed in Pa. This represents the effective thermal conductivity of the fluid, expressed in W / m·K. This indicates the volume grid temperature, in Kelvin (K). Indicates biological components The enthalpy value, in J; Indicates biological components The diffusion flux, described by Fick's law, is expressed in kg / (m³). 2 ·s); This represents the effective stress tensor, with units of N / m. 2 ; This represents the energy source term, with units of W / m³. 3 ; The SIMPLE model was selected for the calculation method. The first-order upwind discrete equation was used for turbulent kinetic energy and dissipation rate, while the second-order upwind discrete equation was used for the calculation of pressure, kinetic energy, energy and each component. The temperature field distribution cloud map inside the furnace was obtained during the simulation process.

2. The numerical model construction method according to claim 1, characterized in that, The organic matter is lean pork or pork fat, where lean pork represents protein and pork fat represents fat.

3. The numerical model construction method according to claim 2, characterized in that, The total moisture content includes free water, moisture in the lean pork, and moisture in the pork fat.

4. The numerical model construction method according to claim 2, characterized in that, The volatile components include the combustible components in the lean pork other than moisture and the combustible components in the fatty pork other than moisture.

5. The numerical model construction method according to any one of claims 1 to 4, characterized in that, In the oxygen bomb calorimetry experiment, the calorific value of the sample is determined by the following formula: ； In the above formula, This indicates the calorific value of the sample, expressed in J / g. This indicates the heat capacity of the calorimetric system, expressed in kJ / ℃. Indicates the initial temperature of the main period. This indicates the end temperature of the main period, in Kelvin (K). This indicates the time interval between ignition and the end of the firing cycle, including the temperature range. It is a positive integer. Indicates the cooling correction value; This indicates the heat generated by the ignition wire. The heat generated by additives other than the ignition wire is expressed in kJ. This indicates the mass of the sample, expressed in kg.

6. The numerical model construction method according to claim 5, characterized in that, The cooling correction value is determined by the following formula: ； In the above formula, This indicates the number of half-minute intervals during the main period where the temperature rises by at least 0.3 K per half-minute. Indicates the initial rate of temperature change. , Indicates the initial temperature. Indicates the rate of temperature change at the end of the period. , This indicates the final temperature, and the unit is K.

7. The numerical model construction method according to any one of claims 1 to 4, characterized in that, The combustion reaction of the nozzle fuel in the cremation model adopts the methane-air-2step model, the radiation in the furnace adopts the P1 model, and the boundary conditions are set based on convection and radiation.

8. The numerical model construction method according to claim 7, characterized in that, The turbulence model in the governing equations adopts the Realizable k-ε model.

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