Method and device for determining temperature field distribution in coke tower reactor

Abstract

The invention provides a method and device for determining temperature field distribution in a coke tower reactor, and the method comprises the steps: carrying out the component analysis and thermal reaction analysis of target heavy oil, so as to determine the lumped component and lumped reaction model of the target heavy oil; establishing a mutual conversion equation group and a heat change equation group among all lumped components according to the lumped reaction model; determining the yield result of each component in the reaction process through a steady-state calculation method; component composition and temperature values are selected from the yields of different components in the reaction process; and by taking the selected component composition and the temperature value as initial values, determining temperature field distribution at different positions in the coke tower in a predetermined reactor by adopting computational fluid mechanics. By means of the scheme, the technical effect that time-space distribution prediction and calculation of the internal temperature field in the whole-cycle production process of the coke tower reactor in the delayed coking technology are established, and therefore the production process can be precisely regulated and controlled can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas exploration, and in particular relates to a method and a device for determining temperature field distribution in a coke drum reactor. Background Art

[0002] The delayed coking unit is the main unit for heavy oil processing, and the coke tower is the reactor of the delayed coking unit. Usually, one heating furnace corresponds to two coke towers, one for coking operation and the other for decoking operation, which are generally switched every 18-24 hours. The coke tower gas circulation preheating technology can safely and accurately preheat the coke tower to the required temperature, so as to meet the conditions for the cracking and condensation reactions of the raw materials in the coke tower, avoid the production of low-strength and low-quality petroleum coke such as shot coke and powder coke, so as to achieve the purpose of improving product quality, energy conservation and emission reduction, and clean production.

[0003] However, for coke tower reactors, the finite element software ANSYS is currently generally used to simulate the preheating, oil intake, steam cooling and water cooling in the coke tower production process, calculate the heat transfer coefficient between the tower wall and the temperature field of the medium inside the tower and predict the life of the tower wall. This method only considers the heat transfer near the tower wall, and does not simulate the flow and reaction conditions inside the coke tower, making it impossible to accurately control the production process. Summary of the invention

[0004] The purpose of the present invention is to provide a method and device for determining the temperature field distribution in a coke drum reactor, to establish a prediction and calculation of the spatiotemporal distribution of the internal temperature field of the coke drum reactor in the full cycle production process in a delayed coking process, so as to accurately control the production process.

[0005] The present invention provides a method for determining the temperature field distribution in a coke drum reactor and a device for implementing the method:

[0006] A method for determining temperature field distribution in a coke drum reactor, the method comprising:

[0007] Performing component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil;

[0008] According to the lumped reaction model, a group of mutual transformation equations and a group of heat change equations between the lumped components are established;

[0009] According to the lumped reaction model, the mutual conversion equation group and the heat change equation group, the yield result of each component in the isothermal reaction process or the variable temperature reaction process is determined by a steady-state calculation method;

[0010] Select component composition and temperature value from the yield results of different components in a constant temperature reaction process or a variable temperature reaction process;

[0011] The selected component composition and temperature values ​​are taken as initial values, and computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum.

[0012] In one embodiment, computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different locations in the coke drum, including:

[0013] Characterizing the heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum and the changes in the amount of substances between the light gas phase, liquid heavy oil and solid coke in the coke drum caused by chemical reactions by the computational fluid dynamics;

[0014] The temperature field distribution at different positions in the coke drum is determined by the computational fluid dynamics.

[0015] In one embodiment, the heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum is expressed as:

[0016] S 1,2 =γ 1,2 A 1,2 (T 2 -T 1 )

[0017] S 1,3 =γ 1,3 A 1,3 (T 3 -T 1 )

[0018] Among them, S 1,2 represents the heat transfer between the gas phase and the liquid phase, S 1,3 It is expressed as the heat transfer between the gas phase and the solid phase, and A represents the contact area between the phases per unit bed volume.

[0019] In one embodiment, according to the lumped reaction model, the mutual conversion equation group and the heat change equation group, the yield result of each component in the isothermal reaction process is determined by a steady-state calculation method, including:

[0020] Setting the reaction temperature of the coke drum to a constant temperature value;

[0021] Under the condition that the influence of heat absorption, heat release and wall heat dissipation in the reaction process on the internal temperature of the coke drum is eliminated, the reaction rate constant is calculated according to the constant temperature value, and the iterative time step in the reaction process is set to the first step;

[0022] According to the lumped reaction model and the mutual conversion equation group, based on the reaction rate constant and the first step length, the change value of the yield of each component over time is calculated.

[0023] In one embodiment, according to the lumped reaction model, the mutual conversion equation group and the heat change equation group, the yield result of each component in the temperature-varying reaction process is determined by a steady-state calculation method, including:

[0024] Setting the initial temperature of the coke drum reaction to a first temperature;

[0025] Under the condition that the endothermic and exothermic effects of the reaction process and the heat dissipation from the wall on the internal temperature of the coke drum are taken into consideration, the reaction rate constant is calculated according to the first temperature, and the iterative time step of the reaction process is set to the second step and the iterative time step of the temperature field is set to the third step;

[0026] According to the lumped reaction model, the group of equations for heat change, the heat values ​​released or absorbed during the reactions of different components, and based on the first temperature, the second step and the third step, the temperature in the coke drum is iteratively updated, and the change in the yield of each component over time is calculated.

[0027] In one embodiment, the selected component composition and temperature value are used as initial values, and computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum, including:

[0028] Initially setting the predetermined reactor according to the selected component composition and temperature value;

[0029] The feed temperature is controlled to be a preset temperature, and evolution is performed through computational fluid dynamics to obtain the temperature distribution trend of the coke drum within a preset time, and radial temperature distribution diagrams at different heights are statistically obtained.

[0030] In one embodiment, the aggregate components of the target heavy oil include: component types and mass fractions of each component type, wherein the component types include at least one of the following: saturated hydrocarbons, aromatic hydrocarbons, resins, soluble asphaltenes, gas phase saturated hydrocarbons, mesophase asphaltenes and coke.

[0031] A device for determining temperature field distribution in a coke drum reactor, comprising:

[0032] An analysis module, used for performing component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil;

[0033] An establishment module is used to establish a group of mutual transformation equations and a group of heat change equations between the lumped components according to the lumped reaction model;

[0034] A determination module, for determining the yield results of each component in a constant temperature reaction process or a variable temperature reaction process by a steady-state calculation method according to the lumped reaction model, the mutual conversion equation group and the heat change equation group;

[0035] A selection module is used to select component composition and temperature value from the yield results of different components in a constant temperature reaction process or a variable temperature reaction process;

[0036] The calculation module is used to use the selected component composition and temperature value as initial values, and use computational fluid dynamics in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum.

[0037] A computing device comprises a processor and a memory for storing instructions executable by the processor, wherein the steps of the above method are implemented when the processor executes the instructions.

[0038] A computer-readable storage medium stores a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0039] The method for determining the temperature field distribution in the coke tower reactor provided by the present invention is to determine the lumped components and lumped reaction model of the target heavy oil by performing component analysis and thermal reaction analysis on the target heavy oil; according to the lumped reaction model, establish a group of mutual conversion equations and a group of heat change equations between the lumped components; according to the lumped reaction model, the group of mutual conversion equations and the group of heat change equations, determine the yield results of each component in the isothermal reaction process or the variable temperature reaction process through a steady-state calculation method; select component composition and temperature values ​​from the yield results of different components in the isothermal reaction process or the variable temperature reaction process; use the selected component composition and temperature values ​​as initial values, and use computational fluid dynamics in a predetermined reactor to determine the temperature field distribution at different positions in the coke tower. That is, through the steady-state calculation simulation method and computational fluid dynamics, the steady-state calculation results are substituted into the computational fluid dynamics as initial values, so that the macro-scale average temperature change law of the coke tower can be characterized, and the non-uniform distribution characteristics of the micro-scale temperature in the coke tower in space can also be described. The above scheme solves the problem that the existing method only considers the heat transfer near the tower wall, does not simulate the flow and reaction conditions inside the coke tower, and thus cannot accurately control the production process. It achieves the technical effect of establishing the prediction and calculation of the spatiotemporal distribution of the internal temperature field of the coke tower reactor in the full cycle production process in the delayed coking process, thereby being able to accurately control the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 It is a method flow chart of an embodiment of a method for determining temperature field distribution in a coke drum reactor provided by the present invention;

[0042] Figure 2 It is a schematic diagram of the reaction kinetic equation provided by the present invention;

[0043] Figure 3 It is a schematic diagram of the change law of the yield of different fractions in the raw material over time determined by steady-state calculation at a temperature of 420° C. provided by the present invention;

[0044] Figure 4 It is a schematic diagram of the change law of the yield of different fractions in the raw material over time determined by steady-state calculation at a temperature of 450° C. provided by the present invention;

[0045] Figure 5 It is a schematic diagram of the change law of the yield of different fractions in the raw material over time determined by steady-state calculation at a temperature of 480° C. provided by the present invention;

[0046] Figure 6 It is a schematic diagram of the change of different components over time in the variable temperature steady-state calculation provided by the present invention;

[0047] Figure 7 It is a schematic diagram of the change of the average temperature of the reactor over time in the variable temperature steady-state calculation provided by the present invention;

[0048] Figure 8 It is a schematic diagram of temperature curves at different heights in a tower in a computational fluid dynamics evolution isothermal reaction process provided by the present invention;

[0049] Fig. 9 It is a schematic diagram of temperature curves at different heights in a tower in a computational fluid dynamics evolution temperature-varying reaction process provided by the present invention;

[0050] Fig.10 The present invention is a schematic diagram of the module structure of an embodiment of a device for determining the temperature field distribution in a coke drum reactor provided by the present invention. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0052] Figure 1 It is a method flow chart of an embodiment of the method for determining the temperature field distribution in the coke tower reactor provided by the present invention. Although the present invention provides method operation steps or device structures as shown in the following embodiments or drawings, more or fewer operation steps or module units may be included in the method or device based on routine or no creative labor. In the steps or structures that do not logically have a necessary causal relationship, the execution order of these steps or the module structure of the device is not limited to the execution order or module structure described in the embodiments of the present invention and shown in the drawings. When the method or module structure is applied to an actual device or terminal product, it can be connected according to the method or module structure shown in the embodiments or drawings for sequential execution or parallel execution (for example, a parallel processor or a multi-threaded processing environment, or even a distributed processing environment).

[0053] Specifically, Figure 1 As shown, the above-mentioned method for determining the temperature field distribution in the coke drum reactor may include the following steps:

[0054] Step 101: performing component analysis and thermal reaction analysis on target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil;

[0055] The aggregate components of the target heavy oil may include but are not limited to: component types and mass fractions of each component type, wherein the component types may include but are not limited to the following substances: saturated hydrocarbons, aromatic hydrocarbons, resins, soluble asphaltenes, gas phase saturated hydrocarbons, mesophase asphaltenes and coke.

[0056] Among them, the lumped reaction model can be: 5 lumped reaction model, 7 lumped reaction model, 11 lumped reaction model, etc. Different lumped reaction models correspond to different activation energy B, pre-exponential factor A and reaction rate constant k i Furthermore, based on the lumped reaction model, the corresponding reaction kinetic equation can be obtained:

[0057]

[0058] Where A is the pre-exponential factor, B is the activation energy of the reaction, T is the reaction temperature, R is the molar gas constant, and k i represents the reaction rate constant.

[0059] Step 102: establishing a group of mutual transformation equations and a group of heat change equations between the lumped components according to the lumped reaction model;

[0060] Among them, the phase heat change can be expressed as:

[0061] S 1,2 =γ 1,2 A 1,2 (T 2 -T 1 )

[0062] S 1,3 =γ 1,3 A 1,3 (T 3 -T 1 )

[0063] Among them, S 1,2 represents the heat transfer between gas and liquid phase, S 1,3 It is expressed as the heat transfer between gas and solid phase. The temperature difference between coke and liquid is small, so it can be ignored. A is the contact area between phases per unit bed volume, T 1 represents the reaction temperature of the gas phase, T 2 represents the reaction temperature of the liquid phase, T 3 Represents the reaction temperature of the solid phase.

[0064] Step 103: Determine the yield results of each component in the isothermal reaction process or the variable temperature reaction process by a steady-state calculation method according to the lumped reaction model, the mutual conversion equation group and the heat change equation group;

[0065] That is, when implementing, in this example, it is divided into a constant temperature process and a variable temperature process, and the calculation method of the component yield is set for both the constant temperature process and the variable temperature process, specifically:

[0066] 1) According to the lumped reaction model, the mutual conversion equation group and the heat change equation group, determining the yield result of each component in the isothermal reaction process by a steady-state calculation method may include:

[0067] S1: setting the reaction temperature of the coke drum to a constant temperature value;

[0068] S2: excluding the effects of heat absorption, heat release and wall heat dissipation in the reaction process on the internal temperature of the coke drum, calculating the reaction rate constant according to the constant temperature value, and setting the iterative time step in the reaction process to the first step;

[0069] S3: According to the lumped reaction model and the mutual conversion equation group, based on the reaction rate constant and the first step length, the change value of the yield of each component over time is calculated.

[0070] 2) According to the lumped reaction model, the mutual conversion equation group and the heat change equation group, determining the yield results of each component in the temperature-varying reaction process by a steady-state calculation method may include:

[0071] S1: setting the initial temperature of the coke drum reaction to a first temperature;

[0072] S2: Under the condition that the endothermic and exothermic effects of the reaction process and the heat dissipation from the wall on the internal temperature of the coke drum are taken into consideration, the reaction rate constant is calculated according to the first temperature, and the iterative time step of the reaction process is set as the second step and the iterative time step of the temperature field is set as the third step, and the same is repeated recursively;

[0073] S3: According to the lumped reaction model, the group of equations for heat change, the heat values ​​released or absorbed during the reactions of different components, and based on the first temperature, the second step and the third step, the temperature inside the coke drum is updated, and the change in the yield of each component over time is calculated.

[0074] Step 104: selecting component composition and temperature value from the yield results of different components in the isothermal reaction process or the variable temperature reaction process;

[0075] For example, the component values ​​when the reaction is carried out for 150 minutes can be selected as the initial conditions. The mass fractions of the components are: saturated hydrocarbons 20.30% (B), aromatic hydrocarbons 2.70% (F), colloids 17.50% (J), soluble asphaltene 6.40% (L), gas phase saturated hydrocarbons 42.63% (a), intermediate phase asphaltene 6.12% (b) and coke 3.71% (c), and the reaction temperature is 420°C. The size of the coke tower is 1.732m in height and 0.32m in diameter. The wall heating temperature is set to 480°C. The temperature distribution of the fluid dynamics evolution reaction for 300s (5min) is calculated, and the radial temperature distribution at different heights is statistically obtained.

[0076] Step 105: Using the selected component composition and temperature value as initial values, computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum.

[0077] In the implementation process, computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum, which can include: characterizing the heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum and the changes in the amount of substances between the light gas phase, liquid heavy oil and solid coke in the coke drum caused by chemical reactions through the computational fluid dynamics; determining the temperature field distribution at different positions in the coke drum through the computational fluid dynamics.

[0078] Specifically, the predetermined reactor can be initially set according to the selected component composition and temperature value; the feed temperature is controlled to be a preset temperature, and evolution is performed through computational fluid dynamics to obtain the temperature distribution trend of the coke tower within a preset time, and radial temperature distribution diagrams at different heights are statistically obtained.

[0079] The above method is described below in conjunction with a specific embodiment. However, it should be noted that this specific embodiment is only for better illustrating the present invention and does not constitute an improper limitation to the present invention.

[0080] In this example, a method for determining the spatiotemporal multi-scale distribution of the temperature field in a coke drum reactor is provided, comprising the following steps:

[0081] Step 1: Perform thermal reaction and component analysis on heavy oil and set basic solution parameters, including the mass fractions of different fractions in the feedstock.

[0082] Among them, the thermal reaction and component analysis of heavy oil include: several lumps of its group composition atmosphere saturated hydrocarbons, aromatic hydrocarbons, colloids and asphaltene, and the calculation of the thermal conversion kinetics of each lumped component.

[0083] Step 2: Determine the reaction lumped model of heavy oil and the kinetic model in the reaction process, including activation energy B, pre-exponential factor A and reaction rate constant k i Etc., and according to the specific heat capacity and standard molar formation enthalpy of different substances in the reaction process of different fractions of the raw materials in step 1.

[0084] Among them, the determination of heavy oil lumped reaction kinetics includes: 5 lumped reaction models, 7 lumped reaction models, 11 lumped reaction models, etc. Different lumped reaction models correspond to different activation energies B, pre-exponential factors A and reaction rate constants k. i .

[0085] Step 3: Constant temperature reaction process:

[0086] According to the reaction kinetics model of step 2, the mutual transformation equations between the components are established. The reaction temperature of the coke tower is set to a constant value T, and the influence of the endothermic and exothermic reaction process and the heat dissipation of the wall on the internal temperature is not considered. The reaction rate constant is calculated according to the current temperature T, and the iterative time step dt of the reaction process is set. According to the reaction lumped model and reaction equation group of step 2, the yield of different fractions in the crude oil is calculated over time.

[0087] The composition of different fractions and the current temperature at any time are calculated and set as initial conditions. The temperature field distribution at different positions in the tower is calculated using the CFD (Computational Fluid Dynamics) method in the selected reactor.

[0088] The reaction temperature T is preferably set between 400-500° C., and the iterative time step of the reaction is set to dt, preferably 0.001-0.01 s.

[0089] Step 4: Temperature-variable reaction process:

[0090] According to the reaction kinetics model of step 2, the mutual conversion equations and heat change equations between the components are established. Set the initial temperature of the coke tower reaction to T0, and consider the effect of the endothermic and exothermic reaction process on the temperature inside the tower. Calculate the reaction rate constant based on the initial temperature T0, set the iterative time step dt of the reaction process and the iterative time step dT of the temperature field update, update the tower temperature based on the reaction lumped model of step 2, the release and absorption heat values ​​of the reaction process of different fractions, and calculate the yield of different fractions.

[0091] According to the characteristics in step 4, different fractions and temperature values ​​at any time are calculated, and used as initial conditions to calculate the temperature field information at different positions in the tower using the CFD method in the selected reactor.

[0092] Among them, the endothermic and exothermic reaction process is mainly due to the change of heat in the tower caused by the cracking and condensation reaction of heavy oil. Set the iteration time step of the reaction process to dt, the temperature field update time step to dT, dt <dT。

[0093] Step 5: Auxiliary analysis of the isothermal reaction process based on computational fluid dynamics (CFD):

[0094] Step 6: Auxiliary analysis of temperature-dependent reaction process based on computational fluid dynamics (CFD):

[0095] Specifically, according to the features described in step 3 and step 4, the method for calculating the spatiotemporal multi-scale distribution of the temperature field in the coke drum reactor includes a steady-state calculation simulation method, and models are established based on constant temperature and variable temperature processes, respectively.

[0096] According to the characteristics described in step 5 and step 6, computational fluid dynamics (CFD) can describe the motion equations of light gas phase, liquid heavy oil and solid coke in the coke drum, including continuity equation and momentum equation. According to the characteristics described in step 5 and step 6, computational fluid dynamics (CFD) can describe the heat exchange and chemical reaction between the three phases of light gas phase, liquid heavy oil and solid coke in the coke drum, causing the amount of substances between the three phases to change. Further, according to the characteristics described in step 5 and step 6, the initial values ​​required by computational fluid dynamics (CFD) include: the composition and the initial temperature are derived from the steady-state calculation simulation method in step 3 and step 4.

[0097] In the above example, the method for calculating the spatiotemporal multi-scale distribution of the temperature field in the coke drum reactor is combined with the steady-state calculation simulation method and computational fluid dynamics. The steady-state calculation results are substituted into the computational fluid dynamics (CFD) as the initial value. The two methods are iteratively calculated to describe the variation law of the macro-scale average temperature of the coke drum, and also to describe the non-uniform distribution characteristics of the micro-scale temperature in the coke drum. It combines the advantages of the fast calculation efficiency of the steady-state calculation simulation method and the high calculation accuracy of computational fluid dynamics (CFD).

[0098] Specifically, the method for calculating the spatiotemporal multi-scale distribution of the temperature field in the coke tower reactor in the above example takes into account the long-term reaction process of the coke tower, calculates the different fractions of the raw materials and the temperature change over time based on the steady-state model, and combines the steady-state calculation simulation method and computational fluid dynamics (CFD) to reflect the temperature evolution law of the coke tower in the long-term reaction process and the characteristics of the non-uniform temperature distribution in the tower.

[0099] The Liaohe vacuum residue is taken as an example for explanation. However, it should be noted that this specific embodiment is only for better explanation of the present invention and does not constitute an improper limitation to the present invention.

[0100] In this example, a method for determining the spatiotemporal multi-scale distribution of the temperature field in a coke drum reactor is provided, which may include the following steps:

[0101] Step 1: Set the basic solution parameters. According to the thermal reaction characteristics of Liaohe vacuum residue, its fraction composition is determined to include saturates (B), aromatics (F), resins (J) and asphaltene (L), with mass fractions of 11.18%, 36.83%, 47.65% and 4.34%, respectively.

[0102] Step 2: Determine the reaction lumped model of heavy oil as 7 lumped reaction kinetic references, correspondingly, Figure 2 As shown, the corresponding reaction kinetic equation is:

[0103]

[0104] Where A is the pre-exponential factor, B is the activation energy of the reaction, T is the reaction temperature, R is the molar gas constant, and k i Represents the reaction rate constant. Specifically, the values ​​of each reaction rate constant can be obtained by experimental determination as shown in Table 1 below:

[0105] Table 1

[0106] <![CDATA[k i ]]> A B(kJ / mol) <![CDATA[k 1 ]]> 29.9 175 <![CDATA[k 2 ]]> 23.43 136 <![CDATA[k 3 ]]> 13.57 85 <![CDATA[k 4 ]]> 17.07 96 <![CDATA[k 5 ]]> 19.34 103 <![CDATA[k 6 ]]> 27.54 168

[0107] Step 3: Determine the molecular weight, specific heat capacity and standard molar formation enthalpy of different fractions including saturated hydrocarbons (B), aromatic hydrocarbons (F), resin (J), asphaltenes (L), gas phase saturated hydrocarbons (a), mesophase asphaltene (b) and coke (c) in the reaction process, as shown in Table 2 below:

[0108] Table 2

[0109] Step 4: Establish the equations for the mutual conversion between the fractions, including saturated fraction (B), aromatic fraction (F), resin (J), soluble asphaltene (L), gas phase saturated hydrocarbons (a), mesophase asphaltene (b) and coke (c). The equation group list can be shown in Table 3 below:

[0110] Table 3

[0111]

[0112]

[0113] Step 5: Figure 3 , Figure 4 and Figure 5 As shown, there are three cases where the reaction temperatures are 420°C, 450°C and 480°C respectively; the reaction iteration time step dt=0.001s is set, and the change law of the yield of different fractions in the raw material over time is determined by steady-state calculation.

[0114] Step 6: Set the initial temperature T0 = 500 °C, set the reaction process iteration time step dt = 0.001s, set the temperature field update time step dT = 0.01s, and establish the heat released and absorbed by the reaction process of different fractions according to the reaction lumped model to update the temperature field in the tower. Determine the temperature field change during the reaction process and the yield of different fractions through steady-state calculation, such as Figure 6 The following shows the variation of different components over time in the variable temperature steady-state calculation. Figure 7 The figure shows the change of the average temperature of the reactor with time in the variable temperature steady-state calculation.

[0115] Step 7: Computational fluid dynamics (CFD) includes the multi-phase and multi-component motion equations of light gas phase, liquid heavy oil and solid coke, namely the continuity equation and momentum exchange equation, as follows:

[0116]

[0117] Where i = 1 represents gas, i = 2 represents liquid petroleum, i = 3 represents solid coke, ε, ρ, μ represent the volume fraction, density and velocity of phase i respectively, R i Represents the mass change caused by chemical reaction, where N i Represents the number of chemical reactions in the i-th phase.

[0118] The momentum equation includes both the gas and liquid phases:

[0119]

[0120]

[0121] Since the fluidity of coke is weak, the velocity of coke is assumed to be 0 (i.e. the generated coke does not move, so there is no need to list the momentum equation of the solid phase), but the solidified and static coke layer has an obstructive effect on the movement of gas and liquid, and the growth diameter of coke is set to 2mm. 12 、F 13 F represents the force between the liquid and solid phases on the gas phase. 12 、F 23 F represents the force exerted by the gas phase and the solid phase on the liquid. 12 and F 21 are two forces of opposite direction and equal magnitude, calculated as follows:

[0122]

[0123]

[0124]

[0125] Among them, u 1 and u 2 Denote the viscosities of the gas phase and liquid phase, respectively, d p represents the growth diameter of coke particles, C 1 , C 3 , C 5 The value of C is 180. 2 , C 4 , C 6 The value of is 1.8.

[0126] Step 8: Computational fluid dynamics (CFD) can describe the heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum and the amount of matter between the three phases caused by chemical reactions. The heat exchange expression between the phases is:

[0127] S 1,2 =γ 1,2 A 1,2 (T 2 -T 1 )

[0128] S 1,3 =γ 1,3 A 1,3 (T 3 -T 1 )

[0129] Among them, S 1,2 represents the heat transfer between gas and liquid phase, S 1,3 It is expressed as the heat transfer between the gas and solid phases. The temperature difference between the coke and the liquid is small, so it can be ignored. A is the interphase contact area per unit bed volume.

[0130] Step 9: Calculate the initial values ​​of fluid dynamics. The initial values ​​include: composition, initial temperature, where the initial temperature can be derived from the steady-state calculation results, and the calculation result of the isothermal reaction process temperature of 420°C is selected. For example: select the component values ​​when the reaction is carried out for 150 minutes as the initial conditions. The mass fractions of each component are: saturated hydrocarbons 20.30% (B), aromatic hydrocarbons 2.70% (F), colloids 17.50% (J), soluble asphaltene 6.40% (L), gas phase saturated hydrocarbons 42.63% (a), intermediate phase asphaltene 6.12% (b) and coke 3.71% (c), and the reaction temperature is 420°C. The dimensions of the coke tower are 1.732m in height and 0.32m in diameter. The wall heating temperature is set to 480°C. The temperature distribution during the CFD evolution reaction of 300s (5min) is as follows: Figure 8 As shown, Figure 8 Shown are temperature curves at different heights in the tower during the computational fluid dynamics evolution isothermal reaction process, that is, radial temperature distribution at different heights.

[0131] Step 10: The results of the temperature-varying reaction calculated by the steady-state model for 50 minutes are used as the initial values ​​of computational fluid dynamics for evolution. The mass fractions of the components are: saturated hydrocarbons 15.07% (B), aromatic hydrocarbons 2.75% (F), colloids 20.64% (J), soluble asphaltene 7.50% (L), gas phase saturated hydrocarbons 42.58% (a), intermediate phase asphaltene 7.11% (b) and coke 4.33% (c). At this time, the reaction temperature is 420°C. The size of the coke tower is 1.732m in height and 0.32m in diameter. The feed temperature is set to 500. The temperature distribution of the CFD evolution reaction for 300s (5min) is as follows: Fig. 9 As shown, Fig. 9 Shown are temperature curves at different heights in the tower during the computational fluid dynamics evolution temperature-swing reaction process, that is, radial temperature distribution at different heights.

[0132] Step 11: Based on the steady-state calculation model, predict the evolution characteristics of the average temperature in the coke drum over time, calculate the spatial distribution characteristics of the temperature field inside the coke drum, and realize the quantitative characterization of multi-scale distribution in time and space.

[0133] Based on the same inventive concept, a device for determining the temperature field distribution in a coke drum reactor is also provided in an embodiment of the present invention, as described in the following embodiments. Since the principle of solving the problem by the device for determining the temperature field distribution in a coke drum reactor is similar to the method for determining the temperature field distribution in a coke drum reactor, the implementation of the device for determining the temperature field distribution in a coke drum reactor can refer to the implementation of the method for determining the temperature field distribution in a coke drum reactor, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived. Fig.10 is a structural block diagram of a device for determining temperature field distribution in a coke drum reactor according to an embodiment of the present invention, such as Fig.10 As shown, it may include: an analysis module 1001, an establishment module 1002, a determination module 1003, a selection module 1004 and a calculation module 1005. The structure is described below.

[0134] The analysis module 1001 is used to perform component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil;

[0135] Establishing module 1002, for establishing a group of mutual conversion equations and a group of heat change equations between the lumped components according to the lumped reaction model;

[0136] A determination module 1003 is used to determine the yield results of each component in a constant temperature reaction process or a variable temperature reaction process by a steady-state calculation method according to the lumped reaction model, the mutual conversion equation group and the heat change equation group;

[0137] A selection module 1004 is used to select component composition and temperature value from the yield results of different components in a constant temperature reaction process or a variable temperature reaction process;

[0138] The calculation module 1005 is used to use the selected component composition and temperature value as initial values, and use computational fluid dynamics in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum.

[0139] In one embodiment, the above-mentioned calculation module 1105 can be specifically used to characterize the heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum and the changes in the amount of substances between the light gas phase, liquid heavy oil and solid coke in the coke drum caused by chemical reactions through the computational fluid dynamics; and determine the temperature field distribution at different positions in the coke drum through the computational fluid dynamics.

[0140] In one embodiment, the heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum can be expressed as:

[0141] S 1,2 =γ 1,2 A 1,2 (T 2 -T 1 )

[0142] S 1,3 =γ 1,3 A 1,3 (T 3 -T 1 )

[0143] Among them, S 1,2 represents the heat transfer between the gas phase and the liquid phase, S 1,3 It is expressed as the heat transfer between the gas phase and the solid phase, and A represents the contact area between the phases per unit bed volume.

[0144] In one embodiment, the above-mentioned determination module 1003 can be specifically used to set the reaction temperature of the coke drum to a constant temperature value; under the condition of excluding the influence of endothermic, exothermic and wall heat dissipation of the reaction process on the internal temperature of the coke drum, the reaction rate constant is calculated according to the constant temperature value, and the iterative time step in the reaction process is set to the first step; according to the lumped reaction model and the mutual transformation equation group, based on the reaction rate constant and the first step, the change value of the yield of each component over time is calculated.

[0145] In one embodiment, the above-mentioned determination module 1003 can be specifically used to set the initial temperature of the coke drum reaction to the first temperature; while considering the influence of endothermic, exothermic and wall heat dissipation of the reaction process on the internal temperature of the coke drum, the reaction rate constant is calculated according to the first temperature, and the iterative time step of the reaction process is set to the second step and the updated iterative time step of the temperature field is set to the third step; according to the lumped reaction model, the group of equations of the heat change equations, and the heat values ​​released or absorbed during the reaction of different components, the temperature inside the coke drum is updated based on the first temperature, the second step and the third step, and the change value of the yield of each component over time is calculated.

[0146] In one embodiment, the above-mentioned calculation module 1005 can be specifically used to perform initial settings on the predetermined reactor according to the selected component composition and temperature value; control the feed temperature to a preset temperature, evolve through computational fluid dynamics, obtain the temperature distribution trend of the coke tower within a preset time, and statistically obtain radial temperature distribution diagrams at different heights.

[0147] In one embodiment, the aggregate components of the target heavy oil may include: component types and mass fractions of each component type, wherein the component types may include but are not limited to the following substances: saturated hydrocarbons, aromatic hydrocarbons, resins, soluble asphaltenes, gas phase saturated hydrocarbons, mesophase asphaltenes and coke.

[0148] The embodiment of the present invention also provides a specific implementation method capable of implementing all the steps in the method for determining the temperature field distribution in the coke drum reactor in the above embodiment. The electronic device specifically includes the following contents: a processor, a memory, a communication interface and a bus; wherein the processor, the memory and the communication interface communicate with each other through the bus; the processor is used to call the computer program in the memory, and when the processor executes the computer program, all the steps in the method for determining the temperature field distribution in the coke drum reactor in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0149] Step 1: performing component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil;

[0150] Step 2: According to the lumped reaction model, a group of mutual transformation equations and a group of heat change equations between the lumped components are established;

[0151] Step 3: Determine the yield results of each component in the isothermal reaction process or the variable temperature reaction process by a steady-state calculation method according to the lumped reaction model, the mutual conversion equation group and the heat change equation group;

[0152] Step 4: Select component composition and temperature value from the yield results of different components in the isothermal reaction process or the variable temperature reaction process;

[0153] Step 5: Using the selected component composition and temperature values ​​as initial values, computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different locations in the coke drum.

[0154] An embodiment of the present invention also provides a computer-readable storage medium capable of implementing all steps of the method for determining the temperature field distribution in the coke drum reactor in the above embodiment. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, all steps of the method for determining the temperature field distribution in the coke drum reactor in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0155] Step 1: performing component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil;

[0156] Step 2: According to the lumped reaction model, a group of mutual transformation equations and a group of heat change equations between the lumped components are established;

[0157] Step 3: Determine the yield results of each component in the isothermal reaction process or the variable temperature reaction process by a steady-state calculation method according to the lumped reaction model, the mutual conversion equation group and the heat change equation group;

[0158] Step 4: Select component composition and temperature value from the yield results of different components in the isothermal reaction process or the variable temperature reaction process;

[0159] Step 5: Using the selected component composition and temperature values ​​as initial values, computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different locations in the coke drum.

[0160] From the above description, it can be seen that the embodiment of the present invention performs component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil; according to the lumped reaction model, establish a group of mutual conversion equations and a group of heat change equations between the lumped components; according to the lumped reaction model, the group of mutual conversion equations and the group of heat change equations, through steady-state calculation, determine the yield results of each component in the isothermal reaction process or the variable temperature reaction process; select component composition and temperature value from the yield results of different components in the isothermal reaction process or the variable temperature reaction process; use the selected component composition and temperature value as initial values, and use computational fluid dynamics in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum. That is, through the steady-state calculation simulation method and computational fluid dynamics, the steady-state calculation results are substituted into the computational fluid dynamics as initial values, so that the macro-scale average temperature change law of the coke drum can be characterized, and the non-uniform distribution characteristics of the micro-scale temperature in the coke drum can also be described. The above scheme solves the problem that the existing method only considers the heat transfer near the tower wall, does not simulate the flow and reaction conditions inside the coke tower, and thus cannot accurately control the production process. It achieves the technical effect of establishing the prediction and calculation of the spatiotemporal distribution of the internal temperature field of the coke tower reactor in the full cycle production process in the delayed coking process, thereby being able to accurately control the production process.

[0161] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the hardware + program embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0162] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0163] Although the present invention provides method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual device or client product is executed, it can be executed in sequence or in parallel according to the method shown in the embodiments or the drawings (for example, in a parallel processor or multi-threaded processing environment).

[0164] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. In the description of this specification, the description of the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, in the absence of contradiction, a person skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0165] The above is only an example of the embodiment of the present specification and is not intended to limit the embodiment of the present specification. For those skilled in the art, the embodiment of the present specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiment of the present specification shall be included in the scope of the claims of the embodiment of the present specification.

Claims

1. A method for determining the temperature field distribution in a coke drum reactor, characterized in that: The method comprises: Performing component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil; According to the lumped reaction model, a group of mutual transformation equations and a group of heat change equations between the lumped components are established; According to the lumped reaction model, the mutual conversion equation group and the heat change equation group, the yield result of each component in the isothermal reaction process or the variable temperature reaction process is determined by a steady-state calculation method; Select component composition and temperature value from the yield results of different components in a constant temperature reaction process or a variable temperature reaction process; The selected component composition and temperature values ​​are taken as initial values, and computational fluid dynamics is used in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum.

2. The method according to claim 1, characterized in that Computational fluid dynamics is used in the predetermined reactor to determine the temperature field distribution at different locations in the coke drum, including: Characterizing the heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum and the changes in the amount of substances between the light gas phase, liquid heavy oil and solid coke in the coke drum caused by chemical reactions by the computational fluid dynamics; The temperature field distribution at different positions in the coke drum is determined by the computational fluid dynamics.

3. The method according to claim 2, characterized in that The heat exchange equation between the light gas phase, liquid heavy oil and solid coke in the coke drum is expressed as: S 1,2 =c 1,2 A 1,2 (T2-T1) S 1,3 =γ 1,3 From 1,3 (T3-T1) Among them, S 1,2 represents the heat transfer between the gas phase and the liquid phase, S 1,3 It is expressed as the heat transfer between the gas phase and the solid phase, A represents the interphase contact area per unit bed volume, T1 represents the reaction temperature of the gas phase, T2 represents the reaction temperature of the liquid phase, and T3 represents the reaction temperature of the solid phase.

4. The method according to claim 1, characterized in that: According to the lumped reaction model, the mutual conversion equation group and the heat change equation group, the yield results of each component in the isothermal reaction process are determined by a steady-state calculation method, including: Setting the reaction temperature of the coke drum to a constant temperature value; Under the condition that the influence of heat absorption, heat release and wall heat dissipation in the reaction process on the internal temperature of the coke drum is eliminated, the reaction rate constant is calculated according to the constant temperature value, and the iterative time step in the reaction process is set to the first step; According to the lumped reaction model and the mutual conversion equation group, based on the reaction rate constant and the first step length, the change value of the yield of each component over time is calculated.

5. The method according to claim 1, characterized in that According to the lumped reaction model, the mutual conversion equation group and the heat change equation group, the yield results of each component in the temperature-varying reaction process are determined by a steady-state calculation method, including: Setting the initial temperature of the coke drum reaction to a first temperature; Under the condition that the endothermic and exothermic effects of the reaction process and the heat dissipation from the wall on the internal temperature of the coke drum are taken into consideration, the reaction rate constant is calculated according to the first temperature, and the iterative time step of the reaction process is set to the second step and the iterative time step of the temperature field is set to the third step; According to the lumped reaction model, the group of equations for heat change, the heat values ​​released or absorbed during the reactions of different components, and based on the first temperature, the second step and the third step, the temperature in the coke drum is iteratively updated, and the change in the yield of each component over time is calculated.

6. The method according to claim 1, characterized in that The selected component composition and temperature values ​​are used as initial values, and computational fluid dynamics is used in the predetermined reactor to determine the temperature field distribution at different locations in the coke drum, including: Initially setting the predetermined reactor according to the selected component composition and temperature value; The feed temperature is controlled to be a preset temperature, and evolution is performed through computational fluid dynamics to obtain the temperature distribution trend of the coke drum within a preset time, and radial temperature distribution diagrams at different heights are statistically obtained.

7. The method according to any one of claims 1 to 6, characterized in that The aggregate components of the target heavy oil include: component types and mass fractions of each component type, wherein the component types include the following substances: saturated hydrocarbons, aromatic hydrocarbons, resins, soluble asphaltenes, gas phase saturated hydrocarbons, mesophase asphaltenes and coke.

8. A device for determining the temperature field distribution in a coke drum reactor, characterized in that: include: An analysis module, used for performing component analysis and thermal reaction analysis on the target heavy oil to determine the lumped components and lumped reaction model of the target heavy oil; An establishment module is used to establish a group of mutual transformation equations and a group of heat change equations between the lumped components according to the lumped reaction model; A determination module, for determining the yield results of each component in a constant temperature reaction process or a variable temperature reaction process by a steady-state calculation method according to the lumped reaction model, the mutual conversion equation group and the heat change equation group; A selection module is used to select component composition and temperature value from the yield results of different components in a constant temperature reaction process or a variable temperature reaction process; The calculation module is used to use the selected component composition and temperature value as initial values, and use computational fluid dynamics in a predetermined reactor to determine the temperature field distribution at different positions in the coke drum.

9. A computing device comprising a processor and a memory for storing instructions executable by the processor, characterized in that: When the processor executes the instructions, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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