CN112329169A - Numerical simulation analysis method for flow and heat transfer process of hot air drum type phoenix Dancong tea green removing machine - Google Patents

Numerical simulation analysis method for flow and heat transfer process of hot air drum type phoenix Dancong tea green removing machine Download PDF

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CN112329169A
CN112329169A CN202011212768.7A CN202011212768A CN112329169A CN 112329169 A CN112329169 A CN 112329169A CN 202011212768 A CN202011212768 A CN 202011212768A CN 112329169 A CN112329169 A CN 112329169A
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tea
hot air
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刘少群
刘成源
郑泽锋
曾志亨
唐婷
马宝淇
韩重阳
胡智标
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South China Agricultural University
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Abstract

The invention discloses a numerical simulation method for a flowing and heat transfer process of a hot air drum type phoenix Dancong tea leaf enzyme deactivating machine, which is scientific and reasonable in structure, good in enzyme deactivating effect, high in efficiency, low in cost and easy to realize. The invention further avoids high cost and technical risk caused by tests or blind design to a certain extent; the numerical simulation analysis process program is easy to realize, and has obvious value for the application of the high-efficiency tea fixation process.

Description

Numerical simulation analysis method for flow and heat transfer process of hot air drum type phoenix Dancong tea green removing machine
Technical Field
The invention relates to an experimental analysis method for actual working conditions in drying process equipment, in particular to a numerical simulation analysis method for a flowing and heat transfer process of a hot air drum type phoenix Dancong tea leaf enzyme deactivating machine, which is applied to the technical field of enzyme deactivating process.
Background
China is the origin of tea trees, and the tea production history is long. According to the data of the national statistical bureau, the area of the tea garden in 2018 is 298.580 ten thousand hectares, and the area of the picked tea garden is 231.076 ten thousand hectares; the tea yield was 261.04 ten thousand tons. The planting scale of tea in China is the first in the world, and the tea consumption in China and even in the whole world is in the rising trend every year, so that the tea tree has high economic value. The tea fixation is a step of destroying and passivating oxidase activity in fresh tea at high temperature, inhibiting enzymatic oxidation of tea polyphenol and the like in the fresh tea, evaporating partial water of the fresh tea to soften the tea, facilitating rolling and forming and promoting the formation of aroma. As the first process of primary tea making, the method is also a key process, and the quality of the produced tea is determined by enzyme deactivation.
During the enzyme deactivation process, the fresh leaves can generate three physical changes of leaf temperature change, water dispersion and volume reduction. During enzyme deactivation, heat transfer between the fresh leaves and the wall of the dryer mainly adopts two modes of heat conduction and convection, and the temperature of the leaves rises by absorbing heat due to the temperature difference between the fresh leaves and the wall of the dryer. During the raising of leaf temperature, the water in leaf is evaporated gradually, the water on leaf surface is first dissipated and then the water in leaf is lost. The analysis shows that the factors influencing the enzyme deactivating effect mainly comprise temperature, time, leaf feeding amount and fresh leaf quality. Wherein, the main influencing factor of enzyme deactivation at high temperature is easy to generate the phenomenon of scorching, and the tender leaves are also scorched; when the temperature is low, the water loss of the enzyme-deactivating leaves is reduced, the water content is increased, and the quality of the enzyme-deactivating leaves is influenced; therefore, to ensure the quality of fixation, the temperature must be controlled within a suitable range.
At present, most of China adopts stir-frying and water-removing, and the defects of uneven water-removing, low heat energy utilization rate and the like exist through a heating roller or a pot and other water-removing machines. The method has the advantages that computer software is used for simulating the water-removing process, so that a discrete field, a flow field and a temperature field in the water-removing process can be obtained, and the method has very important significance for solving the problems of the roller water-removing machine and related water-removing problems, but the existing analysis method for simulating the water-removing process of materials in the roller water-removing machine and the flow and heat transfer values between the materials and a drying medium is not ideal enough, so that the method becomes a technical problem to be solved urgently.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to overcome the defects in the prior art, and provides a numerical simulation method for the heat transfer characteristic of a tea leaf fixation machine, which avoids high cost and technical risks caused by tests or blind design to a certain extent and has important guiding significance for improving fixation quality and tea leaf yield.
In order to achieve the purpose, the invention adopts the following technical scheme:
a heat transfer characteristic numerical simulation method for a tea de-enzyming machine (a method for numerical simulation analysis of a flowing and heat transfer process of a hot air drum type Fenghuang Dancong tea de-enzyming machine) comprises the following steps:
(1) drawing a three-dimensional geometric model diagram of the hot air type roller water-removing machine by using three-dimensional software drawing software:
modeling a three-dimensional model of the fixation machine by using ANSYS; as the preferred technical scheme of the invention, the water-removing machine mainly comprises a feeding and conveying device, a cylinder, a moisture discharging device, a leaf-outlet cooling fan, a far-infrared heat pipe, and the like, wherein when the boundary condition of a avoiding surface is set, the heat transfer coefficient of the wall surface needs to be considered, a new material is created in FLUENT software, and relevant parameters are input according to the physical properties of the material for modeling; when a finite element model of the drum-type green removing machine is established and solved, a numerical simulation method based on FLUENT software is adopted;
(2) establishing a finite element model of the fixation machine and solving the finite element model, wherein the finite element model specifically comprises the following steps:
A. setting the assumed conditions of numerical simulation:
a) the heat dissipation loss in the fixation machine is neglected;
b) the surface of the interior of the fixation machine is free from dirt;
c) the drying medium fluid is ash-free;
d) the drying medium fluid is single-phase (hot air), and the flow rate of the drying medium fluid uniformly flows into the roller of the drying and water-removing machine;
B. analyzing a basic control equation of coupling of a drying medium and tea solids in the tea drying and water-removing machine by using basic physical laws such as a mass conservation equation, an energy conservation equation and a momentum conservation equation followed by fluid flow:
the conservation of mass equation is:
Figure BDA0002759363160000021
the equation of motion is:
Figure BDA0002759363160000022
Figure BDA0002759363160000023
Figure BDA0002759363160000024
the energy equation is:
Figure BDA0002759363160000031
the motion of tea particles in the hot air roller fixation machine meets Newton's second law, and the motion equation of translation and rotation is as follows:
Figure BDA0002759363160000032
Figure BDA0002759363160000033
in the formula: g is the acceleration of gravity; ρ is the fluid density, kg/m 3; u is a fluid velocity vector; mu is dynamic viscosity of fluid, Ps & s; c. CpJ/(kg. k) is the specific heat capacity of the fluid; λ is the thermal conductivity of the fluid, W/(m)2·K)；STIs a viscous dissipation term; si、Sv、SwFor a Newtonian fluid whose viscosity is constant, S is a generalized source termi＝Sv＝Sw0; x, y, z-the velocity component in the three-dimensional direction of the fluid, m/s; m ispgThe mass transfer between the tea particles and the hot air is realized; ε is the volume fraction term; m ispTea particle mass; u. ofpIs the velocity of the tea particles;
Figure BDA0002759363160000034
is a pressure gradient; a momentum transfer coefficient between the two phases; fppThe interaction force among the tea particles is obtained; fpwActing force of tea particles and the wall of the roller; i isPFor rotating tea particlesInertia; w is apIs the angular velocity of the tea particles; mpThe external force moment of the tea particles.
C. Calculating the force of hot air on the particles by using a free fluid resistance model, wherein the resistance coefficient fdDepending on the reynolds number Re:
tea particle motion resistance equation:
Figure BDA0002759363160000035
Figure BDA0002759363160000036
tea particle resistance equation:
Figure BDA0002759363160000037
Figure BDA0002759363160000038
tea particle heat transfer equation:
Qp1p2＝hc(Tp2-Tp1)
Figure BDA0002759363160000039
convection heat transfer between tea particles and hot air:
Figure BDA0002759363160000041
and (3) calculating the convection heat transfer coefficient between the tea particles and hot air:
Figure BDA0002759363160000042
Figure BDA0002759363160000043
in the formula: dpIs the equivalent diameter of the tea particles; u is the relative speed of the tea particles and the hot air; alpha is the free volume of the CFD grid unit of the numerical simulation software; v is the volume of tea particles; fnNormal contact force of tea particles; r is*Is the geometric mean radius of the tea particles;
Figure BDA0002759363160000044
the contact area among the tea particles is defined; k is a radical ofqThe heat conductivity coefficient of hot air; nu (Nu)pIs a dimensionless parameter used for expressing the ratio of the thermal convection rate to the thermal conductivity; m ispIs the mass of the tea particles; cpIs the specific heat capacity of tea particles; t, enzyme deactivation time; h iscThe heat transfer coefficient among tea particles; h ispgIs the heat transfer coefficient between the hot air and the tea particles.
D. With the k-w model, the transport equations of the turbulent kinetic equation k and the diffusion equation w of the fluid are as follows:
Figure BDA0002759363160000045
Figure BDA0002759363160000046
in the formula: gamma-shapedk，ΓwDiffusivity for k and w; gkTurbulent kinetic energy generated for laminar velocity gradient; gwTurbulent kinetic energy generated for the w equation; y isk，YwDissipation of turbulent kinetic energy; dwAre orthogonally divergent.
E. Introducing a three-dimensional geometric model of the hot air drum type phoenix single-fir tea enzyme deactivating machine into Fluent software, establishing a calculation domain and a physical model based on the assumed information of the step A, B, C, D, setting various parameters, and mainly simulating and calculating the fluid flow field distribution, the velocity distribution, the temperature field in the drum type enzyme deactivating machine, the turbulence intensity and the heat transfer performance between the hot air and the tea particles.
F. And (4) designing a hot air drying experiment of the drum-type fixation machine, and comparing and analyzing the numerical simulation result of the step E and the experiment result, so that the applicability of the numerical simulation method is verified.
As the preferred technical scheme of the invention, the hot air drum type Fenghuang Dancong tea de-enzyming machine system mainly comprises: the tea leaf water-removing machine comprises a heating system, a water-removing roller, an induced air system, a pipeline system, a feeding system, a heat recovery device and a discharging system, wherein the heating system heats natural air through the heating device, and then the induced air system introduces hot air into the water-removing machine to heat and remove water of tea leaves in the roller; the feeding system conveys materials to the roller fixation machine, and hot air is led out of the roller by the air induction system after fixation is carried out on tea leaves in the roller; the heat recovery device collects the heat of the waste hot air extracted by the air inducing system for reuse so as to improve the overall energy utilization rate of the tea leaf fixation machine system.
The numerical simulation analysis method for the flowing and heat transfer process of the hot-air drum-type phoenix Dancong tea enzyme deactivating machine is preferentially suitable for the numerical simulation calculation process of the hot-air drum-type enzyme deactivating machine on the wet plant porous material.
Compared with the prior art, the invention has the following obvious prominent substantive characteristics and salient points:
1. the invention provides a numerical simulation analysis method for the flow and heat transfer processes in a green removing machine by using a hot air drum type phoenix Dancong tea green removing machine which has a scientific and reasonable structure, a good green removing effect, high efficiency, low cost and easiness in realization.
The invention avoids high cost and technical risk caused by tests or blind design to a certain extent;
the numerical simulation analysis process of the invention is easy to realize, and has significant value for the high-efficiency tea fixation process.
Drawings
FIG. 1 is a schematic structural diagram of a water-removing apparatus according to an embodiment of the present invention.
Detailed Description
The above-described scheme is further illustrated below with reference to specific embodiments, which are detailed below:
the first embodiment is as follows:
in this embodiment, referring to fig. 1, the hot air drum type phoenix Dancong tea leaf green removing machine used in this embodiment mainly comprises: the tea leaf water-removing machine comprises a heating system, a water-removing roller, an induced air system, a pipeline system, a feeding system, a heat recovery device and a discharging system, wherein the heating system heats natural air through the heating device, and then the induced air system introduces hot air into the water-removing machine to heat and remove water of tea leaves in the roller; the feeding system conveys materials to the roller fixation machine, and hot air is led out of the roller by the air induction system after fixation is carried out on tea leaves in the roller; the heat recovery device collects the heat of the waste hot air extracted by the air inducing system for reuse so as to improve the overall energy utilization rate of the tea leaf fixation machine system. The numerical simulation analysis method for the flowing and heat transfer process of the drum-type de-enzyming machine is suitable for the numerical simulation calculation process of the hot air drum-type phoenix Dancong tea de-enzyming machine on the wet plant porous materials.
In the embodiment, referring to fig. 1, a numerical simulation method for heat transfer characteristics of a tea leaf fixation machine is used for performing numerical simulation on tea leaf moisture evaporation in the fixation machine used with a hot air drum type phoenix single-fir tea leaf fixation machine, and comprises the following steps;
(1) drawing a three-dimensional geometric model diagram of the hot air type roller water-removing machine by using three-dimensional software drawing software:
modeling a three-dimensional model of the fixation machine by using ANSYS;
establishing a three-dimensional model by using ANSYS embedded modeling software, setting a surface avoiding boundary condition by considering a wall surface heat transfer coefficient, establishing a new material in FLUENT software, and inputting related parameters for modeling according to physical properties of the material;
secondly, establishing a finite element model of the hot air drum type phoenix Dancong tea green removing machine and solving, wherein the finite element model is a numerical simulation method based on FLUENT in the embodiment;
(2) establishing a finite element model of the fixation machine and solving the finite element model, wherein the finite element model specifically comprises the following steps:
A. the movement of tea leaves in the water-removing machine is complex, the heat and mass transfer process in the water-removing machine is considered, the heat and mass transfer process for completely reproducing the movement of the tea leaves by adopting a numerical simulation method is difficult, and an ideal result is not easy to obtain. Therefore, the numerical simulation of the dewatering process of the tea leaves in the hot air drum type phoenix single-fir tea green removing machine of the embodiment is mainly based on the following assumptions;
a) neglect of heat dissipation loss in the enzyme deactivation machine
b) The surface of the interior of the fixation machine is free from dirt, namely the subsequent calculation is simple and convenient, and the interior of the machine is assumed to be an ideal environment;
c) the drying medium fluid does not contain ash, and the dried residue, namely the ash, can be left in the enzyme deactivating process under the actual condition, but the final solution result is not greatly influenced after the final enzyme deactivating is finished;
d) the drying medium fluid is single-phase (hot air), and the flow rate of the drying medium fluid uniformly flows into the roller of the drying and water-removing machine;
B. analyzing a basic control equation of coupling of a drying medium and tea solids in the tea drying and water-removing machine by using basic physical laws such as a mass conservation equation, an energy conservation equation and a momentum conservation equation followed by fluid flow:
the conservation of mass equation is:
Figure BDA0002759363160000061
the equation of motion is:
Figure BDA0002759363160000062
Figure BDA0002759363160000063
Figure BDA0002759363160000064
the energy equation is:
Figure BDA0002759363160000071
the motion of tea particles in the hot air roller fixation machine meets Newton's second law, and the motion equation of translation and rotation is as follows:
Figure BDA0002759363160000072
Figure BDA0002759363160000073
in the formula: g is the acceleration of gravity; ρ is the fluid density, kg/m 3; u is a fluid velocity vector; mu is dynamic viscosity of fluid, Ps & s; c. CpJ/(kg. k) is the specific heat capacity of the fluid; λ is the thermal conductivity of the fluid, W/(m)2·K)；STIs a viscous dissipation term; si、Sv、SwFor a Newtonian fluid whose viscosity is constant, S is a generalized source termi＝Sv＝Sw0; x, y, z-the velocity component in the three-dimensional direction of the fluid, m/s; m ispgThe mass transfer between the tea particles and the hot air is realized; ε is the volume fraction term; m ispTea particle mass; u. ofpIs the velocity of the tea particles;
Figure BDA0002759363160000074
is a pressure gradient; beta twoThe interphase momentum transfer coefficient; fppThe interaction force among the tea particles is obtained; fpwActing force of tea particles and the wall of the roller; i isPIs the moment of inertia of tea particles; w is apIs the angular velocity of the tea particles; mpThe external force moment of the tea particles.
C. Calculating the force of hot air on the particles by using a free fluid resistance model, wherein the resistance coefficient fdDepending on the reynolds number Re:
tea particle motion resistance equation:
Figure BDA0002759363160000075
Figure BDA0002759363160000076
tea particle resistance equation:
Figure BDA0002759363160000077
Figure BDA0002759363160000078
tea particle heat transfer equation:
Qp1p2＝hc(Tp2-Tp1)
Figure BDA0002759363160000079
convection heat transfer between tea particles and hot air:
Figure BDA0002759363160000081
and (3) calculating the convection heat transfer coefficient between the tea particles and hot air:
Figure BDA0002759363160000082
Figure BDA0002759363160000083
in the formula: dpIs the equivalent diameter of the tea particles; u is the relative speed of the tea particles and the hot air; alpha is the free volume of the CFD grid unit of the numerical simulation software; v is the volume of tea particles; fnNormal contact force of tea particles; r is*Is the geometric mean radius of the tea particles;
Figure BDA0002759363160000084
the contact area among the tea particles is defined; k is a radical ofqThe heat conductivity coefficient of hot air; nu (Nu)pIs a dimensionless parameter used for expressing the ratio of the thermal convection rate to the thermal conductivity; m ispIs the mass of the tea particles; cpIs the specific heat capacity of tea particles; t, enzyme deactivation time; h iscThe heat transfer coefficient among tea particles; h ispgIs the heat transfer coefficient between the hot air and the tea particles.
D. With the k-w model, the transport equations of the turbulent kinetic equation k and the diffusion equation w of the fluid are as follows:
Figure BDA0002759363160000085
Figure BDA0002759363160000086
in the formula: gamma-shapedk，ΓwDiffusivity for k and w; gkTurbulent kinetic energy generated for laminar velocity gradient; gwTurbulent kinetic energy generated for the w equation; y isk，YwDissipation of turbulent kinetic energy; dwAre orthogonally divergent.
E. Introducing a three-dimensional geometric model of the hot air drum type phoenix single-fir tea enzyme deactivating machine into Fluent software, establishing a calculation domain and a physical model on the basis of the assumption and information of the step A, B, C, D, setting various parameters, and mainly simulating and calculating the fluid flow field distribution, the speed distribution, the temperature field in the drum of the enzyme deactivating machine, the turbulence intensity and the heat transfer performance between the hot air and the tea particles.
F. And (4) designing a hot air drying experiment of the drum-type fixation machine, and comparing and analyzing the numerical simulation result of the step E and the experiment result, so that the applicability of the numerical simulation method is verified.
According to the method for numerical simulation analysis of the flow and heat transfer processes in the green removing machine, numerical calculation is carried out on the water removing process of tea leaves in the drum-type green removing machine and the heat and mass transfer processes between the tea leaves and hot fluid by adopting the computational fluid dynamics software FLUENT, so that high cost and raw material waste caused by experiments or blind design are avoided, and certain guiding significance is provided for improving the green removing quality of the tea leaves.
Example two:
this embodiment is substantially the same as the first embodiment, and is characterized in that:
in this embodiment, hot-blast drum-type phoenix single fir tea de-enzyming machine system mainly includes: heating system, de-enzyming roller, air inducing and feeding system, pipeline system, feeding system, heat recovering device and discharging system. According to the numerical simulation analysis method for the flow and heat transfer processes in the green removing machine, numerical calculation is carried out on the water removing process of tea leaves in the drum-type green removing machine and the heat and mass transfer processes between the tea leaves and hot fluid by adopting computational fluid dynamics software FLUENT, the obtained result perfects the green removing and water removing mechanism, the method has obvious value and important guiding significance for improving the high-efficiency tea leaf green removing process, and high cost and technical risks caused by tests or blind design are avoided to a certain extent.
The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various changes may be made according to the purpose of the invention, and any changes, modifications, substitutions, combinations or simplifications made according to the spirit and principle of the technical solution of the present invention shall be equivalent substitutions, as long as the purpose of the present invention is met, and the technical principle and the inventive concept of the method for numerically simulating and analyzing the flow and heat transfer process of the hot air drum type phoenix single-fir tea leaf enzyme deactivating machine of the present invention shall fall within the protection scope of the present invention.

Claims (5)

1. A heat transfer characteristic numerical simulation method for a tea leaf enzyme deactivating machine (a method for numerical simulation analysis of the flowing and heat transfer processes of a hot air drum type Fenghuang Dancong tea leaf enzyme deactivating machine) is characterized by comprising the following steps of:
(1) drawing a three-dimensional geometric model diagram of the fixation machine by using three-dimensional drawing software:
modeling a three-dimensional model of the green removing machine by using a modeling module in ANSYS;
(2) establishing a finite element model of the fixation machine and solving the finite element model, wherein the finite element model specifically comprises the following steps:
A. setting the assumed conditions of numerical simulation:
a) the heat dissipation loss in the fixation machine is neglected;
b) the surface of the interior of the fixation machine is free from dirt;
c) the drying medium fluid is ash-free;
d) the drying medium fluid is single-phase (hot air), and the flow rate of the drying medium fluid uniformly flows into the roller of the drying and water-removing machine;
B. analyzing a basic control equation of coupling of a drying medium and tea solids in the tea drying and water-removing machine by using basic physical laws such as a mass conservation equation, an energy conservation equation and a momentum conservation equation followed by fluid flow:
the conservation of mass equation is:
Figure FDA0002759363150000011
the equation of motion is:
Figure FDA0002759363150000012
Figure FDA0002759363150000013
Figure FDA0002759363150000014
the energy equation is:
Figure FDA0002759363150000015
the motion of tea particles in the hot air roller fixation machine meets Newton's second law, and the motion equation of translation and rotation is as follows:
Figure FDA0002759363150000016
Figure FDA0002759363150000017
in the formula: g is the acceleration of gravity; rho is the fluid density, kg/m3(ii) a U is a fluid velocity vector; mu is dynamic viscosity of fluid, Ps & s; c. CpJ/(kg. k) is the specific heat capacity of the fluid; λ is the thermal conductivity of the fluid, W/(m)2·K)；STIs a viscous dissipation term; si、Sv、SwFor a Newtonian fluid whose viscosity is constant, S is a generalized source termi＝Sv＝Sw0; x, y, z-the velocity component in the three-dimensional direction of the fluid, m/s; m ispgThe mass transfer between the tea particles and the hot air is realized; ε is the volume fraction term; m ispTea particle mass; u. ofpIs the velocity of the tea particles;
Figure FDA0002759363150000021
is a pressure gradient; coefficient of momentum transfer between beta two phases；FppThe interaction force among the tea particles is obtained; fpwActing force of tea particles and the wall of the roller; i isPIs the moment of inertia of tea particles; w is apIs the angular velocity of the tea particles; mpThe external force moment of the tea particles.
C. Calculating the force of hot air on the particles by using a free fluid resistance model, wherein the resistance coefficient fdDepending on the reynolds number Re:
tea particle motion resistance equation:
Figure FDA0002759363150000022
Figure FDA0002759363150000023
tea particle resistance equation:
Figure FDA0002759363150000024
Figure FDA0002759363150000025
tea particle heat transfer equation:
Qp1p2＝hc(Tp2-Tp1)
Figure FDA0002759363150000026
convection heat transfer between tea particles and hot air:
Figure FDA0002759363150000027
and (3) calculating the convection heat transfer coefficient between the tea particles and hot air:
Figure FDA0002759363150000028
Figure FDA0002759363150000031
in the formula: dpIs the equivalent diameter of the tea particles; u is the relative speed of the tea particles and the hot air; alpha is the free volume of the CFD grid unit of the numerical simulation software; v is the volume of tea particles; fnNormal contact force of tea particles; r is*Is the geometric mean radius of the tea particles;
Figure FDA0002759363150000032
the contact area among the tea particles is defined; k is a radical ofqThe heat conductivity coefficient of hot air; nu (Nu)pIs a dimensionless parameter used for expressing the ratio of the thermal convection rate to the thermal conductivity; m ispIs the mass of the tea particles; cpIs the specific heat capacity of tea particles; t, enzyme deactivation time; h iscThe heat transfer coefficient among tea particles; h ispgIs the heat transfer coefficient between the hot air and the tea particles.
D. With the k-w model, the transport equations of the turbulent kinetic equation k and the diffusion equation w of the fluid are as follows:
Figure FDA0002759363150000033
Figure FDA0002759363150000034
in the formula: gamma-shapedk，ΓwDiffusivity for k and w; gkTurbulent kinetic energy generated for laminar velocity gradient; gwTurbulent kinetic energy generated for the w equation; y isk，YwIs turbulent flowDissipation of energy; dwAre orthogonally divergent.
E. A three-dimensional geometric model of a hot air drum type phoenix single-fir tea enzyme deactivating machine is introduced into Fluent software, a calculation domain and a physical model are established based on the assumed condition of A, B, C, D, various parameters are set, and the fluid flow field distribution, the velocity distribution, the temperature field in the drum type enzyme deactivating machine drum, the turbulence intensity and the heat transfer performance between hot air and tea particles of the drum type enzyme deactivating machine are mainly simulated and calculated.
F. And (4) designing a hot air drying experiment of the drum-type fixation machine, and comparing and analyzing the numerical simulation result of the step E and the experiment result, so that the applicability of the numerical simulation method is verified.
2. The method for numerical simulation analysis of the flowing and heat transfer process of the hot-air drum-type phoenix Dancong tea green removing machine according to claim 1, wherein: in the step (1), the ANSYS is used for establishing a full-size three-dimensional physical model for the hot-air drum type Fenghuang oolong tea leaf enzyme deactivating machine, the tea leaf enzyme deactivating machine is large in actual size, the number of generated divided grids is large, and in order to reduce the grid dividing difficulty and the calculation cost, the model needs to be simplified and then subjected to grid division and heat transfer area grid encryption.
3. The method for numerical simulation analysis of the flowing and heat transfer process of the hot-air drum-type phoenix Dancong tea green removing machine according to claim 1, wherein: hot-blast cylinder phoenix Dancong tea wrap machine system mainly includes: the tea leaf water-removing machine comprises a heating system, a water-removing roller, an induced air system, a pipeline system, a feeding system and a discharging system, wherein the heating system heats natural air through a heating device, then the induced air system introduces hot air into the water-removing machine to heat and remove water of tea leaves in the roller, the feeding system conveys materials into the roller water-removing machine, and the hot air is led out of the roller through the induced air system after the tea leaves are removed with water in the roller.
4. The method for numerical simulation analysis of the flowing and heat transfer process of the hot-air drum-type phoenix Dancong tea green removing machine according to claim 3, wherein: the method is suitable for the numerical simulation calculation process of the hot air drum type phoenix Dancong tea green removing machine on the wet plant porous material.
5. The method for numerical simulation analysis of the flowing and heat transfer process of the hot-air drum-type phoenix Dancong tea green removing machine according to claim 1, wherein: when the wall boundary conditions are set, the wall heat transfer coefficient needs to be considered, and when a hot air drum type phoenix Dancong tea model is established and solved, a numerical simulation method based on Fluent software is adopted.
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