CN107505352B - Method and device for evaluating flow heat exchange of hydrocarbon fuel in one-dimensional channel - Google Patents
Method and device for evaluating flow heat exchange of hydrocarbon fuel in one-dimensional channel Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 60
- 239000000446 fuel Substances 0.000 title claims abstract description 59
- 239000004215 Carbon black (E152) Substances 0.000 title claims abstract description 57
- 229930195733 hydrocarbon Natural products 0.000 title claims abstract description 57
- 150000002430 hydrocarbons Chemical class 0.000 title claims abstract description 57
- 238000004364 calculation method Methods 0.000 claims abstract description 95
- 239000012530 fluid Substances 0.000 claims abstract description 28
- 238000011156 evaluation Methods 0.000 claims abstract description 26
- 230000000704 physical effect Effects 0.000 claims abstract description 10
- 238000005336 cracking Methods 0.000 claims description 62
- 238000004939 coking Methods 0.000 claims description 55
- 230000008878 coupling Effects 0.000 claims description 36
- 238000010168 coupling process Methods 0.000 claims description 36
- 238000005859 coupling reaction Methods 0.000 claims description 36
- 230000008569 process Effects 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 12
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 9
- 239000005977 Ethylene Substances 0.000 claims description 9
- 238000004590 computer program Methods 0.000 claims description 8
- 230000001186 cumulative effect Effects 0.000 claims description 6
- 238000001816 cooling Methods 0.000 description 21
- 239000002826 coolant Substances 0.000 description 11
- 238000010521 absorption reaction Methods 0.000 description 8
- 238000004422 calculation algorithm Methods 0.000 description 8
- 230000006870 function Effects 0.000 description 7
- 238000004088 simulation Methods 0.000 description 6
- 239000000571 coke Substances 0.000 description 5
- 238000000197 pyrolysis Methods 0.000 description 5
- 238000011160 research Methods 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
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- 230000007017 scission Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- WQJBDEHULKUMKX-UHFFFAOYSA-N [5-(2-aminoethyl)-2-hydroxyphenyl] benzoate Chemical compound NCCC1=CC=C(O)C(OC(=O)C=2C=CC=CC=2)=C1 WQJBDEHULKUMKX-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
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- 239000002245 particle Substances 0.000 description 1
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Abstract
The invention discloses a flow heat exchange evaluation method of hydrocarbon fuel in a one-dimensional channel, which divides a one-dimensional pipe into N small sections and defines N+1 nodes; acquiring initial guess values of the outlet temperature and the temperature field; calculating to obtain the pressure of the 1 st node, obtaining the physical property of the fluid, calculating the Reynolds number of the 1 st node, and finishing the operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid; calculating pressure drop by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment to obtain the pressure of the 2 nd node, and updating the temperature of the 2 nd node; and sequentially performing iterative analogies to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel. For a long straight channel, the method greatly reduces the calculated amount, improves the calculation speed and effectively reduces the calculation time while ensuring that the calculation accuracy is slightly reduced. The invention also discloses a device for evaluating the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel.
Description
Technical Field
The invention relates to the technical field of aerospace, in particular to a method and a device for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel.
Background
The cooling system is one of key systems on the aerospace vehicle, and the cooling characteristics of the coolant need to be studied intensively for designing the cooling system with excellent performance. In the actual cooling process, hydrocarbon fuel is used as a coolant, physical and chemical heat absorption is carried out along with the flow of the hydrocarbon fuel in a cooling channel, and meanwhile, a large amount of micromolecular compounds are generated by self-pyrolysis, coking reaction can further occur at a higher temperature, coke is separated from pyrolysis products and deposited on the inner wall of the cooling channel, and a coking layer can increase the thermal resistance between the wall surface and the coolant, so that the cooling effect is adversely affected. At present, a great deal of research on the flow heat exchange of hydrocarbon fuel in a cooling channel has been carried out, and complex simulation of the flow, heat exchange, cracking and other processes of the hydrocarbon fuel in a three-dimensional flow channel can be realized by an aircraft comprehensive thermal management analysis program (Vehicle Integrated Thermal Management Code, VITMAC for short), a NANCY program developed by France MBDA, an MOSAR program developed by France ONERA, a computing program RTE (Rocket Thermal Evaluation) developed by M.H. N.Naragh and the like. Few coking simulation programs for hydrocarbon fuels exist, mainly Krazinski et al model the coking of fuel based on Chemical Fluid Dynamics (CFDC). However, the prior art has significant drawbacks: the calculation time is very long. The cooling channel is very complex, large-scale three-dimensional calculation is needed, even if a parallel calculation technology is adopted, the problem of too large calculation amount is not solved, and the parallel efficiency is continuously reduced along with the increase of the number of parallel CPUs, so that poor economical efficiency is caused.
Disclosure of Invention
Based on the above, it is necessary to provide a method and a device for evaluating the flow heat exchange of hydrocarbon fuel in a one-dimensional channel, aiming at the problems existing in the conventional technology, and in an actual cooling system, the long straight channel occupies more than 60% of the whole cooling channel. For a long straight channel, the one-dimensional algorithm greatly reduces the calculation amount, improves the calculation speed and effectively reduces the calculation time while ensuring that the calculation accuracy is slightly reduced. The one-dimensional flow heat exchange calculation has very high application potential in the research of cooling systems, has better engineering application value for the simulation of cracking and coking processes, and is a green efficient algorithm.
In a first aspect, an embodiment of the present invention provides a method for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel, where the method includes: dividing a one-dimensional tube into N small segments from a 1 st segment to an N th segment, and defining N+1 nodes, wherein the subscript symbol on the right side of N represents the number of nodes, and the 0 th node to the N th node; obtaining an initial guess value of an outlet temperature and a temperature field, wherein the outlet temperature is obtained by presetting an inlet specific heat number as an average specific heat of the whole one-dimensional tube length, and the initial guess value of the temperature field is obtained by presetting the temperature in the one-dimensional tube along linear distribution, and is used as the initial guess value of the temperature field; selecting an inlet Reynolds number as an initial guess value of an average Reynolds number of the 1 st micro-segment, calculating pressure drop to obtain the pressure of the 1 st node, obtaining fluid physical properties from the temperature and the pressure of the 1 st node, calculating the Reynolds number of the 1 st node, and finishing the operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid; calculating pressure drop by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment to obtain the pressure of the 2 nd node, and updating the temperature of the 2 nd node; and sequentially performing iterative analogies to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel.
In one embodiment, the method further comprises: and completing the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel through calculation of flow heat exchange cracking coupling.
In one embodiment, the operation of calculating the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel through the flow heat exchange cracking coupling comprises the following steps: for the first iteration step, obtaining inlet conditions, boundary conditions and geometric conditions of the tube length of the cracking section through the monitored cracking starting point, obtaining and cracking temperature, pressure and speed of each point of the first iteration step,
wherein, the formula is:
x py →L→dx
calculating the average temperature and residence time of the fluid in each micro-segment through the temperature and the speed of the first iteration step;
calculating the concentration of the coolant of the next node and the concentration of each generated component according to the concentration of the coolant of the previous node, and obtaining the heat absorption capacity of the cracking reaction according to the concentration difference;
wherein, the formula is:
wherein,is the average temperature and residence time of each micro-segment,/->Is the molar concentration of the first iteration step component j at the ith node, the superscript indicates the iteration step number, the subscript j indicates the component number, and the subscript i indicates the ith node. />Is the average heat absorption of the ith micro-segment.
In one embodiment, the method further comprises: and finishing the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel through the flow heat exchange cracking coking coupling calculation.
In one embodiment, the evaluating operation for completing the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel through the flow heat exchange cracking coking coupling calculation comprises: ethylene concentration is obtained through the calculation of the cracking reaction, and the inner diameter of the flow channel after the preset first time step is calculated; obtaining a temperature field and a pressure field through flow heat exchange cracking coupling, obtaining ethylene concentration as a preset condition of a second time step, and obtaining the inner diameter of a flow channel; and carrying out cumulative addition calculation on the coking amount in each preset time step, taking the cumulative addition calculation into the flow thermal exchange cracking coupling calculation process, and analogically iterating the operation until reaching the preset total coking time.
In one embodiment, the method further comprises: judging the coking amount, if the coking amount is excessive, stopping the coking calculation when the flow channel is 0 or the inlet-outlet pressure drop is greater than half of the inlet pressure, and outputting the coking time at the moment;
wherein, the formula is:
in a second aspect, an embodiment of the present invention provides a computer readable storage medium, where a computer program is stored, where the computer program, when executed by a processor, implements the method for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to the first aspect.
In a third aspect, embodiments of the present invention provide a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the first aspect described above.
In a fourth aspect, an embodiment of the present invention further provides a device for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel, where the device includes: the dividing module divides the one-dimensional tube into N small segments from the 1 st segment to the N th segment, and defines N+1 nodes, wherein the subscript symbol on the right side of N represents the number of nodes, and the 0 th node to the N th node; the temperature field initial guess value is a temperature of each node obtained by linearly distributing the temperature in the preset one-dimensional tube, and is used as the initial guess value of the temperature field; the first calculation and updating module is used for selecting an inlet Reynolds number as a preliminary guess value of the average Reynolds number of the 1 st micro-segment to calculate pressure drop, obtaining the pressure of the 1 st node, obtaining fluid physical properties from the temperature and the pressure of the 1 st node, calculating the Reynolds number of the 1 st node, and finishing the operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid; the second calculation and updating module is used for calculating the pressure drop by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment to obtain the pressure of the 2 nd node and updating the temperature of the 2 nd node; and the iteration and evaluation module is used for sequentially performing iteration analogizing operation to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel.
The invention provides a method and a device for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel, wherein a one-dimensional pipe is divided into N small sections from a 1 st section to an N th section, and N+1 nodes are defined, wherein subscript symbols on the right side of N represent the number of nodes, and the number of nodes is 0 th to N th; obtaining an initial guess value of an outlet temperature and a temperature field, wherein the outlet temperature is obtained by presetting an inlet specific heat number as an average specific heat of the whole one-dimensional tube length, and the initial guess value of the temperature field is obtained by presetting the temperature in the one-dimensional tube along linear distribution, and is used as the initial guess value of the temperature field; selecting an inlet Reynolds number as an initial guess value of an average Reynolds number of the 1 st micro-segment, calculating pressure drop to obtain the pressure of the 1 st node, obtaining fluid physical properties from the temperature and the pressure of the 1 st node, calculating the Reynolds number of the 1 st node, and finishing the operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid; calculating pressure drop by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment to obtain the pressure of the 2 nd node, and updating the temperature of the 2 nd node; and sequentially performing iterative analogies to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel. The method is based on the fact that in an actual cooling system, the long straight channel occupies more than 60% of the whole cooling channel, and the one-dimensional algorithm is used for the long straight channel, so that the calculation accuracy is ensured to be slightly reduced, the calculation amount is greatly reduced, the calculation speed is improved, and the calculation time is effectively shortened. The one-dimensional flow heat exchange calculation has very high application potential in the research of cooling systems, has better engineering application value for the simulation of cracking and coking processes, and is a green efficient algorithm.
Drawings
FIG. 1 is a schematic flow chart of a method for evaluating the flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment of the invention;
FIG. 2 is a schematic flow chart of a flow-through heat exchange coupling procedure in a method for evaluating flow-through heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment of the present invention;
FIG. 3 is a schematic flow chart of a flow heat exchange cracking coupling procedure in a method for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment of the present invention;
FIG. 4 is a schematic flow chart of a flow heat exchange cracking coking coupling procedure in a method for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment of the present invention;
FIG. 5 is a graphical representation of an initial condition input interface for a flow heat transfer evaluation method for hydrocarbon fuel in a one-dimensional channel in accordance with one embodiment of the present invention; and
fig. 6 is a schematic structural diagram of a device for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment of the present invention.
Detailed Description
In order to make the purposes, technical schemes and advantages of the invention more clear, the method and the device for evaluating the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel are further described in detail below with reference to the accompanying drawings and the embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Fig. 1 is a schematic flow chart of a method for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment. The method specifically comprises the following steps:
and 101, dividing the one-dimensional tube into N small segments from the 1 st segment to the N th segment, and defining N+1 nodes, wherein the index symbol on the right side of N represents the number of nodes, and the 0 th node to the N th node.
Step 102, obtaining an initial guess value of an outlet temperature and a temperature field, wherein the outlet temperature is obtained by presetting an inlet specific heat number as an average specific heat of the whole one-dimensional tube length, and the initial guess value of the temperature field is obtained by presetting the temperature in the one-dimensional tube along linear distribution, and is used as the initial guess value of the temperature field.
Step 103, selecting an inlet Reynolds number as an initial guess value of the 1 st micro-segment average Reynolds number, calculating pressure drop, obtaining the pressure of the 1 st node, obtaining fluid physical properties from the temperature and the pressure of the 1 st node, calculating the Reynolds number of the 1 st node, and finishing the operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid.
And 104, calculating the pressure drop by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment to obtain the pressure of the 2 nd node, and updating the temperature of the 2 nd node.
And 105, sequentially performing iterative analogizing operation to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel.
In one embodiment, the method for evaluating the flow heat exchange of hydrocarbon fuel in a one-dimensional channel provided by the present disclosure further includes: and completing the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel through the calculation of the flow heat exchange cracking coupling.
Specifically, the operation of completing the evaluation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel by calculating the flow heat exchange cracking coupling comprises the following steps: for the first iteration step, obtaining inlet conditions, boundary conditions and geometric conditions of the tube length of the cracking section through the monitored cracking starting point, obtaining and cracking temperature, pressure and speed of each point of the first iteration step,
wherein, the formula is:
x py →L→dx
calculating the average temperature and residence time of the fluid in each micro-segment through the temperature and the speed of the first iteration step;
calculating the concentration of the coolant of the next node and the concentration of each generated component according to the concentration of the coolant of the previous node, and obtaining the heat absorption capacity of the cracking reaction according to the concentration difference;
wherein, the formula is:
wherein,is the average temperature and residence time of each micro-segment,/->Is the molar concentration of the first iteration step component j at the ith node, the superscript indicates the iteration step number, the subscript j indicates the component number, and the subscript i indicates the ith node. />Is the average heat absorption of the ith micro-segment.
Further, in one embodiment, the method for evaluating the flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to the present disclosure further includes: and (3) performing coupling calculation through flow heat exchange cracking coking to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel.
Specifically, the operation of completing the evaluation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel through the flow heat exchange cracking coking coupling calculation comprises the following steps: ethylene concentration is obtained through the calculation of the cracking reaction, and the inner diameter of the flow channel after the preset first time step is calculated; obtaining a temperature field and a pressure field through flow heat exchange cracking coupling, obtaining ethylene concentration as a preset condition of a second time step, and obtaining the inner diameter of a flow channel; and carrying out cumulative addition calculation on the coking amount in each preset time step, taking the cumulative addition calculation into the flow thermal exchange cracking coupling calculation process, and analogically iterating the operation until reaching the preset total coking time.
Still further, in one embodiment, the method for evaluating the flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to the present disclosure further includes: judging the coking amount, if the coking amount is excessive, stopping the coking calculation when the flow channel is 0 or the inlet-outlet pressure drop is greater than half of the inlet pressure, and outputting the coking time at the moment;
wherein, the formula is:
wherein, the coking amount of each node in the first time step; is the mass of carbon produced at each node in the first time step; is the flow channel inner diameter obtained for each node in the first time step taking into account the coking-generated carbon particles.
The invention provides a flow heat exchange evaluation method of hydrocarbon fuel in a one-dimensional channel, which divides a one-dimensional pipe into N small sections from a 1 st section to an N th section, and defines N+1 nodes, wherein the subscript symbol on the right side of N represents the number of nodes, and the nodes from 0 th node to N th node; obtaining an initial guess value of an outlet temperature and a temperature field, wherein the outlet temperature is obtained by presetting an inlet specific heat number as an average specific heat of the whole one-dimensional tube length, and the initial guess value of the temperature field is obtained by presetting the temperature in the one-dimensional tube along linear distribution, and is used as the initial guess value of the temperature field; selecting an inlet Reynolds number as an initial guess value of an average Reynolds number of the 1 st micro-segment, calculating pressure drop to obtain the pressure of the 1 st node, obtaining fluid physical properties from the temperature and the pressure of the 1 st node, calculating the Reynolds number of the 1 st node, and finishing the operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid; calculating pressure drop by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment to obtain the pressure of the 2 nd node, and updating the temperature of the 2 nd node; and sequentially performing iterative analogies to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel. The method is based on the fact that in an actual cooling system, the long straight channel occupies more than 60% of the whole cooling channel, and the one-dimensional algorithm is used for the long straight channel, so that the calculation accuracy is ensured to be slightly reduced, the calculation amount is greatly reduced, the calculation speed is improved, and the calculation time is effectively shortened. The one-dimensional flow heat exchange calculation has very high application potential in the research of cooling systems, has better engineering application value for the simulation of cracking and coking processes, and is a green efficient algorithm.
In order to more clearly understand and apply the method for evaluating the flow heat exchange of hydrocarbon fuel in the one-dimensional channel, which is provided by the invention, the following example is carried out. It should be noted that the scope of the present invention is not limited by the following examples.
With reference to fig. 2-5. FIG. 2 is a schematic flow chart of a flow-through heat exchange coupling procedure in a method for evaluating flow-through heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment; FIG. 3 is a schematic flow chart of a flow heat exchange cracking coupling procedure in a method for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment; FIG. 4 is a schematic flow chart of a flow heat exchange cracking coking coupling procedure in a method for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment; FIG. 5 is a graphical representation of an initial condition input interface for a flow heat transfer evaluation method for hydrocarbon fuel in a one-dimensional channel using a program in accordance with one embodiment.
Specifically, the one-dimensional tube is divided into N small segments (1 st segment to N th segment) and has N+1 nodes (note: subscript represents the number of nodes, 0 th node to N th node). In the 1 st iteration step, the inlet specific heat number is selected as the average specific heat of the whole pipe length to obtain the outlet temperature, and the temperature of each node is obtained by assuming that the temperature in the pipe is linearly distributed, and the temperature is used as the initial guess value of the temperature field. Then, the inlet Reynolds number is selected as an initial guess value of the average Reynolds number of the 1 st micro-segment to calculate pressure drop, the pressure of the 1 st node is obtained, the physical property of the fluid is obtained through the temperature and the pressure of the 1 st node, the Reynolds number of the 1 st node is calculated, the Reynolds number and the temperature of the 1 st micro-segment fluid are updated, then the Reynolds number of the 1 st node is used as an initial guess value of the average Reynolds number of the 2 nd micro-segment to calculate pressure drop, the pressure of the 2 nd node is obtained, and the temperature of the 2 nd node is updated. And so on, as shown in the following formula:
it should be noted that the subscript indicates the number of nodes, the superscript indicates the number of iteration steps, the average of the representative micro-segments with bars above the parameters, and, in particular,the average specific heat of the first i segments in the kth iteration step is shown.
Note that ncyc is a global variable representing the number of iterative steps k in the program.
Further, the flow heat exchange cracking coupling calculation is to take the energy change caused by the heat absorption of the cracking reaction into consideration to perform the flow heat exchange calculation, so as to obtain a temperature field and a speed field. The known heat absorption capacity obtained by the first iteration step through calculation of the initial field of the cracking section is brought into an energy equation of a heat exchange program, and the flow heat exchange coupling calculation is carried out on the cracking section to obtain an initial temperature field and a speed field of the second iteration step. In the second iteration step, new average temperature and residence time of each micro-segment are obtained from the initial field, heat absorption is calculated, flow heat exchange coupling calculation is carried out again, the initial field of the third iteration step is obtained, and the mass fractions of the coolant and the components of each node of the final cracking segment and the temperature field and the pressure field of the whole cracking segment are obtained by analogy.
Note that ncyc and pyncyc are global variables representing the number of flow heat exchange iteration steps and the number of cracking iteration steps k in the program, idpyron is a global variable for performing cracking calculation control, and when cracking occurs in a tube, idpyron=1 starts cracking calculation.
Furthermore, the flow heat exchange cracking coking coupling calculation is performed by considering the diameter change of the flow channel in the pipe caused by coking reaction, so as to obtain a temperature field and a speed field. Knowing the ethylene concentration obtained by calculation of the cracking reaction, obtaining a new inner diameter of the flow channel after the first time step, obtaining a new temperature field and a new pressure field through flow heat exchange cracking coupling, obtaining a new ethylene concentration at the same time, taking the new ethylene concentration as the condition of the second time step to obtain a new inner diameter of the flow channel, taking the coking amount of each time step to be accumulated, taking the coking amount into the flow heat exchange cracking coupling calculation process again, and the like until the set total coking time is reached. If the coking amount is excessive, stopping the coking calculation when the flow channel is 0 or the inlet-outlet pressure drop is greater than half of the inlet pressure, and outputting the coking time at the moment.
Note that ncyc and pyncyc are global variables representing the number of flow heat exchange iteration steps and the number of cracking iteration steps k in a program, idcoon is a global variable for performing coking calculation control, and when a coking process needs to be calculated, idcoon=1 starts coking calculation.
It can be understood that the one-dimensional calculation program HiTrans1D is an engineering calculation program aiming at the problems of heat exchange, cracking and coking coupling of hydrocarbon fuel flowing in a single tube, and the program is written in the FORTRAN 90 language. Through calculation control statement, hiTrans1D can realize one-dimensional flow heat exchange coupling calculation, one-dimensional flow heat exchange cracking coupling calculation and one-dimensional flow heat exchange cracking coking process coupling calculation.
The program comprises a main program (main), various computing subroutines (flow), a condition reading subroutines (condition), a computing content control subroutines (control), a result output subroutines (output), a physical library subroutines (property), various criteria association and models are recorded in a function form (function), and all global variables are packaged in the module (module_definition). The following describes the respective parts of the procedure: main program (main) main.f90 is a flow control that implements the entire one-dimensional computation. Firstly, performing flow heat exchange coupling calculation, and after convergence, performing coupling calculation of flow heat exchange, cracking and coking according to the setting content in control.f90; calculate content control subroutine (control): the function of control. F90 is to open inputdata. Txt (read in file), read the set calculation control conditions. The method comprises the steps of cracking calculation identification, coking calculation identification, time step and total time of coking calculation, total iteration step number, initial temperature of cracking reaction and round tube junction number, wherein the calculation content is specified by setting the parameters; condition reading subroutine (condition): the condition. F90 function is to open inputdata. Txt (read in file), read the set initial conditions. Including inlet conditions (temperature, pressure, reynolds number), geometry (tube length, tube inside diameter, tube outside diameter), boundary conditions (wall heat flow), other conditions (tube thermal conductivity, carbon thermal conductivity). Introducing the inlet temperature and the inlet pressure into a physical subroutine property.f90 to obtain inlet physical parameters (density, viscosity, heat conductivity coefficient and specific heat), wherein the conditions are initial conditions of the whole one-dimensional rapid calculation; calculation subroutine (flow, heat, analysis, cake, cake_non, cake_analysis): flow.f90, heat trans.f90, pyrolysis.f90, coke.f90 correspond to the flow, heat exchange, cracking, coke calculation subroutine, respectively. One-dimensional flow heat exchange coupling calculation is realized by flow.f90 and heattrans.f90, one-dimensional flow heat exchange cracking coupling calculation is realized by flow.f90 and pyrolysis.f90, and one-dimensional flow heat exchange cracking coking process coupling calculation is realized by flow.f90, heattrans.f90, pyrolysis.f90 and coke.f90; global variable encapsulation (module_define): all global variables needed in one-dimensional computation are defined in module_define.f90; property library subroutine (property): property.f90 is a program for calculating fuel properties, which has been developed autonomously by the subject group. The temperature and pressure of the fluid are known, and the physical parameters (density, viscosity, heat conductivity coefficient and specific heat) corresponding to the fluid can be obtained. The applicable temperature range is 300-1050K, and the pressure range is 1-15MPa; function library (function): functions. F90 contains all of the criterion relations in the one-dimensional computation. For different calculations, the corresponding criterion relation is provided; result output subroutine (output): the output.f90 function is to output different result files for different computing content. By identifying the cracking calculation identification and the coking calculation identification, output.f90 can output four result files of only flow heat exchange, considering cracking reaction, considering coking reaction and different coking time.
Further, the program using steps are as follows: opening inputdata. Txt setting conditions; the initial conditions needed by the program operation mainly comprise inlet conditions, boundary conditions, geometric conditions and calculation control conditions. Wherein whether a 1 in the typeface is calculated represents calculation and 0 represents no calculation. As shown in FIG. 4, the default channel in the process has a thermal conductivity of 129W/(mK), cokeDensity of 500kg/m 3 Filling in according to actual conditions, and taking the calculation of the text as the reference of default data; running a program; extracting calculation results in the output file aiming at different calculation contents; the output files include temp. txt, flow. Txt, heattrans. Txt, potty. Txt, massfrac. Txt, molarfrac. Txt, crackingdegree. Txt, and cake. Txt, wherein temp. txt includes the length coordinates along the tube, the tube inner diameter, the fluid temperature, the tube inner wall temperature, and the tube outer wall temperature. flow. Txt includes coordinates along the length of the tube, tube inside diameter, fluid velocity, reynolds number, pressure; the heattrans.txt includes the coordinates along the tube length, the tube inside diameter, the convective heat transfer coefficient, the nucels number, and the prandtl number; porty. Txt along the length of the tube, inside diameter of the tube, fluid density, viscosity, specific heat at constant pressure, coefficient of thermal conductivity; massfrac.txt includes the coordinates along the tube length, the mass fraction of coolant, the mass fraction of cleavage product in 1 st to 18 th; molarfrac.txt includes the coordinates along the length of the tube, the mole fraction of coolant, the mole fraction of cleavage product in 1 st to 18 th; the crackingdegre. Txt includes the cracking degree of the coolant along the tube length coordinates; the coke.txt comprises the length coordinates of the tube, the mass concentration of precipitated carbon and the coking amount; and processing and analyzing the data.
Based on the same inventive concept, a device for evaluating the flow heat exchange of hydrocarbon fuel in a one-dimensional channel is also provided. Because the principle of solving the problem of the device is similar to that of the method for evaluating the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel, the implementation of the device can be repeated according to the specific step time limit of the method, and the repeated parts are not repeated.
Fig. 6 is a schematic structural diagram of a device for evaluating flow heat exchange of hydrocarbon fuel in a one-dimensional channel according to an embodiment. The flow heat exchange evaluation device 10 of hydrocarbon fuel in the one-dimensional channel includes: the system comprises a partitioning module 100, an acquisition module 200, a first calculation and update module 300, a second calculation and update module 400 and an iteration and evaluation module 500.
The dividing module 100 is configured to divide the one-dimensional tube into N small segments from the 1 st segment to the N th segment, and define n+1 nodes, where the subscript symbol on the right side of N represents the number of nodes, and the 0 th node to the N th node; the obtaining module 200 is configured to obtain an initial guess value of an outlet temperature and a temperature field, where the outlet temperature is an initial guess value of the temperature field, the initial guess value of the temperature field is an initial guess value of the temperature of each node obtained by linearly distributing the temperature in the preset one-dimensional tube, and the initial guess value of the temperature field is obtained by presetting an inlet specific heat number as an average specific heat of the whole one-dimensional tube length; the first calculation and update module 300 is configured to select an inlet reynolds number as a preliminary guess value of a 1 st micro-segment average reynolds number to calculate a pressure drop, obtain a 1 st node pressure, obtain fluid physical properties from a 1 st node temperature and pressure, calculate a 1 st node reynolds number, and complete an operation of updating the 1 st micro-segment fluid reynolds number and temperature; the second calculation and update module 400 is configured to calculate a pressure drop by using the reynolds number of the 1 st node as the initial guess value of the average reynolds number of the 2 nd micro-segment, obtain the pressure of the 2 nd node, and update the temperature of the 2 nd node; the iteration and evaluation module 500 is used for sequentially performing iteration analogizing operation to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel.
According to the flow heat exchange evaluation device for hydrocarbon fuel in the one-dimensional channel, the one-dimensional pipe is divided into N small sections from the 1 st section to the N th section through the dividing module 100, and N+1 nodes are defined, wherein the subscript symbol on the right side of N represents the number of nodes, and the 0 th node is up to the N th node; obtaining initial guess values of an outlet temperature and a temperature field through an obtaining module 200, wherein the outlet temperature is obtained by presetting an inlet specific heat number as the average specific heat of the whole one-dimensional tube length, and the initial guess value of the temperature field is obtained by presetting the temperature in the one-dimensional tube along linear distribution, and is used as the initial guess value of the temperature field; selecting an inlet Reynolds number as a preliminary guess value of an average Reynolds number of a 1 st micro-segment through a first calculation and updating module 300, calculating pressure drop to obtain pressure of the 1 st node, obtaining fluid physical properties through temperature and pressure of the 1 st node, calculating the Reynolds number of the 1 st node, and finishing operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid; the pressure drop is calculated by the second calculation and updating module 400 by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment, so as to obtain the pressure of the 2 nd node, and the temperature of the 2 nd node is updated; and finally, sequentially performing iterative analogizing operation through the iterative and evaluating module 500 to complete the evaluating operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel. The device ensures that the calculation amount is greatly reduced, the calculation speed is improved, and the calculation time is effectively reduced for the long straight channel based on the one-dimensional algorithm when the long straight channel occupies more than 60% of the whole cooling channel in the actual cooling system. The one-dimensional flow heat exchange calculation has very high application potential in the research of cooling systems, has better engineering application value for the simulation of cracking and coking processes, and is a green efficient algorithm.
The embodiment of the invention also provides a computer readable storage medium. The computer readable storage medium has stored thereon a computer program that is executed by the processor of fig. 1-5.
Embodiments of the present invention also provide a computer program product comprising instructions. The computer program product, when run on a computer, causes the computer to perform the methods of fig. 1 to 5 described above.
Those skilled in the art will appreciate that implementing all or part of the above-described methods in accordance with the embodiments may be accomplished by way of a computer program stored on a computer readable storage medium, which when executed may comprise the steps of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), or the like.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (2)
1. A method of flow heat exchange evaluation of hydrocarbon fuel in a one-dimensional channel, the method comprising:
dividing the one-dimensional tube into N small sections, wherein the N small sections from the 1 st section to the N th section comprise N+1 nodes;
obtaining an initial guess value of an outlet temperature and a temperature field, wherein the outlet temperature is obtained by presetting an inlet specific heat number as an average specific heat of the whole one-dimensional tube length, and the initial guess value of the temperature field is obtained by presetting the temperature in the one-dimensional tube along linear distribution, and is used as the initial guess value of the temperature field;
selecting an inlet Reynolds number as an initial guess value of an average Reynolds number of the 1 st micro-segment, calculating pressure drop to obtain the pressure of the 1 st node, obtaining fluid physical properties from the temperature and the pressure of the 1 st node, calculating the Reynolds number of the 1 st node, and finishing the operation of updating the Reynolds number and the temperature of the 1 st micro-segment fluid;
calculating pressure drop by taking the Reynolds number of the 1 st node as the initial guess value of the average Reynolds number of the 2 nd micro-segment to obtain the pressure of the 2 nd node, and updating the temperature of the 2 nd node;
sequentially performing iterative analogies to complete the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel;
further comprises: judging the coking amount, if the coking amount is excessive, stopping the coking calculation when the inner diameter of the flow channel is 0 or the inlet and outlet pressure drops are greater than half of the inlet pressure, and outputting the coking time at the moment;
the evaluation operation of the flow heat exchange of the hydrocarbon fuel in the one-dimensional channel is completed through flow heat exchange cracking coking coupling calculation, and the method specifically comprises the following steps:
ethylene concentration is obtained through the calculation of the cracking reaction, and the inner diameter of the flow channel after the preset first time step is calculated;
obtaining a temperature field and a pressure field through flow heat exchange cracking coupling, obtaining ethylene concentration as a preset condition of a second time step, and obtaining the inner diameter of a flow channel;
and carrying out cumulative addition calculation on the coking amount in each preset time step, taking the cumulative addition calculation into the flow thermal exchange cracking coupling calculation process, and analogically iterating the operation until reaching the preset total coking time.
2. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements the method according to claim 1.
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| CN101413933A (en) * | 2007-10-17 | 2009-04-22 | 中国科学院工程热物理研究所 | Flow, heat transfer and heat-absorbing reaction integrative measuring apparatus of supercritical fluid |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101413933A (en) * | 2007-10-17 | 2009-04-22 | 中国科学院工程热物理研究所 | Flow, heat transfer and heat-absorbing reaction integrative measuring apparatus of supercritical fluid |
Non-Patent Citations (3)
| Title |
|---|
| 《Numerical Study of Flow and Heat Transfer of n-Decane with Pyrolysis and Pyrolytic Coking under Supercritical Pressures》;Zhi Tao et al.;《Energy & Fuels》;第31卷;第8699页左栏第2段,第8699页左栏第4段-第8701页左栏第1段及图1 * |
| 《吸热型碳氢燃料流动传热与裂解过程耦合机理及其控制方法》;冯宇 等;《中国航天第三专业信息网第三十八届技术交流会暨第二届空天动力联合会议论文集——液体推进技术》;第2页最后一段-第4页第6段及图1 * |
| 冯宇 等.《吸热型碳氢燃料流动传热与裂解过程耦合机理及其控制方法》.《中国航天第三专业信息网第三十八届技术交流会暨第二届空天动力联合会议论文集——液体推进技术》.2017,第2页最后一段-第4页第6段及图1. * |
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