Polyethylene heating device and control method thereof

Abstract

The invention relates to the technical field of polyethylene processing, in particular to a polyethylene heating device and a control method thereof.The polyethylene heating device comprises a base, and supporting pads are installed at the four corners of the bottom of the base. Hot air generated in the heating barrel in the heating process enters a spiral heat conduction pipe through an air inlet pipe and then preheats a polyethylene raw material in a preheating barrel, so that the subsequent heating time of the polyethylene raw material in the heating barrel is shortened; when a rotating rod is subjected to angle adjustment, a movable rod can be lifted through a connecting block, so that an extrusion block is driven to circularly extrude the bottom of the heating barrel to enable the heating barrel to vibrate, and a polyethylene raw material adhered to the inner side wall of the heating barrel can be conveniently shaken down after heating; therefore, the problems that in the heating process of a traditional polyethylene heating device, the polyethylene raw material is inconvenient to preheat, and the residual raw material in the heating barrel is inconvenient to clean, so that resources are wasted are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of polyethylene processing, in particular to a polyethylene heating device and a control method thereof. Background Art

[0002] Polyethylene is a thermoplastic resin formed by the polymerization of ethylene monomers. With its excellent physical properties, chemical stability and low cost, it has become one of the largest and most widely used plastic materials in the world today. The appearance of polyethylene is usually milky white, translucent or opaque, and feels waxy. It also has good waterproof and moisture resistance. Its chemical properties are stable, acid and alkali corrosion resistant, insoluble in general solvents at room temperature, and has good electrical insulation properties. In addition, polyethylene also has good processing properties and thermoplasticity. It can be processed into products of various shapes and sizes by injection molding, blow molding, extrusion and other methods. Heating is an indispensable part of its processing and molding process. It can not only change the morphology and properties of polyethylene, but also optimize its processing and use performance. Traditional polyethylene heating devices are not convenient for preheating polyethylene raw materials during the heating process. Therefore, the raw materials are at room temperature each time they are heated, which prolongs the heating time and reduces the production efficiency. In addition, after the heated raw materials are discharged, the residual raw materials will stick to the inner wall of the heating barrel and it is not convenient to clean them out, resulting in a waste of resources and certain disadvantages.

[0003] In summary, the present invention solves the existing problems by designing a polyethylene heating device and a control method thereof. Summary of the invention

[0004] The object of the present invention is to provide a polyethylene heating device and a control method thereof to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A polyethylene heating device comprises a base, support pads are installed at the four corners of the bottom of the base, support columns are installed at the four corners of the top of the base, a support frame is installed on the top of the support columns, two groups of telescopic rods are symmetrically installed at both ends of the top of the support frame, and reset springs are installed on the outer ring surfaces of the telescopic rods. Connecting plates are installed on the tops of the two groups of telescopic rods at both ends of the top of the support frame, respectively, a heating barrel is installed between the outer sides of the connecting plates and above the support frame, a discharge pipe is installed at the bottom of the heating barrel, a feed pipe is installed at one end of the inner top of the heating barrel, a first cavity is opened inside the inner side wall of the heating barrel, a heating wire is installed inside the first cavity, a stirring motor is installed at the center of the inner top of the heating barrel, a support plate is installed on the output shaft of the stirring motor, a stirring shaft is installed at the three corners of the bottom of the support plate, and a plurality of stirring rods are installed on the outer ring surface of the stirring shaft;

[0007] The top of the heating barrel is provided with an air inlet pipe, a preheating barrel is provided at the center position of the top of the heating barrel, a second cavity is opened inside the inner side wall of the preheating barrel, a spiral heat conducting pipe is provided inside the second cavity, an air outlet pipe is provided at one end of the outer ring surface of the preheating barrel, a feed port is provided at the top of the preheating barrel, a vertical plate is provided at the top of the base, a driving motor is provided at one end of the wider side of the outside of the vertical plate, a turntable is provided at one end of the side of the outside of the vertical plate away from the driving motor, a movable rod is provided at the edge of the outer side surface of the turntable, a rotating rod is provided at one end of the movable rod, a cylindrical block is provided inside the end of the rotating rod away from the movable rod and located on the vertical plate, a connecting block is provided outside the rotating rod, a vertical rod is provided on the top of the connecting block, an extrusion block is provided on the top of the vertical rod, a plurality of fixing rods are provided at equal intervals on the inner side wall of the support frame, a circular plate is provided at one end of the fixing rod away from the support frame, and a sleeve is provided at the bottom of the circular plate.

[0008] As a preferred solution of the present invention, four groups of telescopic rods and reset springs are provided, and the telescopic rods and reset springs are symmetrically arranged at both ends of the top of the support frame, and the connecting plate and the heating barrel are connected by bolts.

[0009] As a preferred solution of the present invention, the top of the feed pipe passes through the heating barrel and extends to the inner bottom of the preheating barrel, and the feed pipe does not interfere with the support plate during rotation. Solenoid valves are installed inside the feed pipe and the discharge pipe.

[0010] As a preferred solution of the present invention, one end of the air inlet pipe passes through the interior of the heating barrel, and the end of the air inlet pipe away from the heating barrel passes through the interior of the first cavity and is connected to one end of the spiral heat pipe, and the end of the spiral heat pipe away from the air inlet pipe is connected to the external air outlet pipe.

[0011] As a preferred solution of the present invention, the output shaft of the driving motor passes through the vertical plate and is connected to the outside of the turntable, and one end of the movable rod is rotatably connected to one end of the outer side surface of the turntable.

[0012] As a preferred solution of the present invention, the end of the movable rod away from the turntable is rotatably connected to one end of the rotating rod, the cylindrical block is fixedly connected to the outside of the vertical plate, and the inside of one end of the rotating rod is rotatably connected to the outer annular surface of the cylindrical block.

[0013] As a preferred solution of the present invention, the bottom end of the connecting block is rotatably connected to the outside of the rotating rod, and the top end of the connecting block is rotatably connected to the bottom end of the vertical rod.

[0014] As a preferred solution of the present invention, one end of the top of the vertical rod passes through the inner wall of the sleeve and then through the circular plate to be connected to the bottom of the extrusion block, and the outer annular surface of the vertical rod is slidably connected to the inner wall of the sleeve and the inside of the circular plate.

[0015] The present invention also discloses a control method for a polyethylene heating device, which specifically comprises the following steps:

[0016] Step 1: First, inject polyethylene raw materials into the heating barrel and the preheating barrel. The raw materials inside the heating barrel can be heated by the heating wire. Start the stirring motor. The stirring motor drives the support plate to rotate and simultaneously drives multiple groups of stirring shafts to rotate. The polyethylene raw materials heated inside the heating barrel are stirred by the stirring rod to make the polyethylene raw materials mixed more evenly and thus speed up the heating speed.

[0017] Step 2: During the heating process, hot air is generated inside the heating barrel and enters into the interior of the spiral heat pipe through the air inlet pipe. Since the water inside the first cavity absorbs the heat of the hot air inside the spiral heat pipe, the polyethylene raw material inside the preheating barrel is preheated, thereby accelerating the subsequent heating time of the polyethylene raw material inside the heating barrel, thereby achieving energy saving. The heated polyethylene raw material can be discharged through the discharge pipe, and then the preheated polyethylene raw material inside the preheating barrel can be poured into the heating barrel through the feed pipe.

[0018] Step three: The driving motor drives the turntable to rotate and simultaneously drives the movable rod to rotate. When the turntable drives the movable rod to rotate, it drives the rotating rod to adjust the angle with the cylindrical block as the center. When the rotating rod adjusts the angle, the vertical rod can be lifted and lowered through the connecting block. The sliding connection between the vertical rod, the circular plate and the sleeve increases the stability of the lifting and lowering of the vertical rod, thereby driving the extrusion block to cyclically extrude the bottom of the heating barrel, and stretching the telescopic rod and the reset spring while squeezing the heating barrel up. When the vertical rod descends, the restriction of the reset spring is released, driving the heating barrel to descend, thereby vibrating the heating barrel, so that the polyethylene raw material sticking to the inner wall of the heating barrel after heating is shaken off, and then discharged through the discharge pipe, avoiding waste of resources.

[0019] As a preferred solution of the present invention, the polyethylene heating device is intelligently controlled by an intelligent control algorithm, and the specific process is as follows;

[0020] Step 1: Sensor installation and data collection;

[0021] Point temperature sensors: platinum resistance thermometers (RTDs), installed at the inlet, center, and outlet of the heating barrel to monitor temperature distribution;

[0022] Power meter: monitors the actual power consumed by the heating element and is usually installed on the power line to accurately measure the heating power;

[0023] Flow rate sensor: Ultrasonic flow meter, installed in the heating barrel to monitor the flow rate of polyethylene;

[0024] Torque sensor: Installed on the stirring device, it measures the torque during stirring to evaluate stirring load and viscosity changes;

[0025] Pressure sensor: installed at the appropriate position of the heating barrel to monitor the pressure changes of polyethylene during processing;

[0026] Ambient temperature and humidity sensors: monitor the temperature and humidity of the work area environment to help adjust the control strategy to adapt to environmental changes;

[0027] Step 2: System modeling;

[0028] A physical model describing the heat transfer process of polyethylene in a heating barrel is established; the model is based on the heat conduction equation:

[0029]

[0030] Where T is temperature, t is time, x is position, α is the thermal diffusivity of the material, β is a coefficient related to the power of the heating device, and P(t) is the heating power at time t;

[0031] Discretize the above continuous-time physical model in space and time;

[0032] Spatial discretization:

[0033]

[0034] Where T represents temperature, x represents position, Δx represents the change in position; i is the spatial index, which represents the discretized position; k is the time step, which represents the number of time steps after discretization; T i k represents the temperature at the i-th spatial position and the k-th time step; represents the temperature at the i+1th spatial position and the kth time step; represents the temperature at the i-1th spatial position and the kth time step; represents the finite difference of the second-order spatial derivative;

[0035] Time discretization:

[0036]

[0037] Among them, T represents temperature, t represents time, i is the spatial index, which represents the discretized position; k is the time step, which represents the number of time steps after discretization; Δt represents the change in time, T i k represents the temperature at the i-th spatial position and the k-th time step; T i k+1 represents the temperature at the ith spatial position and the k+1th time step; represents the first-order time derivative;

[0038] Using the finite difference method for spatial derivatives and the Euler method for temporal derivatives, the discretized spatial and temporal derivatives are substituted into the original equations to obtain the combined discretization:

[0039]

[0040] Among them, i is the spatial index, which indicates the discretized position; k is the time step, which indicates the number of time steps after discretization; Δt indicates the change in time, Δx indicates the change in position; T indicates temperature, t indicates time, x indicates position, α is the thermal diffusivity of the material, and β is a coefficient related to the power of the heating device; T i k represents the temperature at the i-th spatial position and the k-th time step; T i k+1 represents the temperature at the ith spatial position and the k+1th time step; represents the temperature at the i+1th spatial position and the kth time step; represents the temperature at the i-1th spatial position and the kth time step; Pk represents the heating power at the kth time step;

[0041] Step 3: Convert the discretized model into state space;

[0042] Convert the discrete model to state-space form:

[0043] T k+1 =AT k +Bp k

[0044] Among them, T k+1 represents the temperature vector at the k+1th time step; T k represents the temperature vector at the kth time step, A and B are the corresponding system matrix and input matrix; P k represents the heating power vector at the kth time step;

[0045] At each time step, MPC determines the optimal heating power P by solving the following optimization problem;

[0046]

[0047] Among them, T k+j represents the predicted temperature, which is the temperature of the jth future time step predicted at time step k; j represents the index of the predicted time step; is the target temperature, Q is the weight matrix used to adjust the weight of the temperature error, R is the weight matrix used to adjust the weight of the control input, P T represents the transpose of the heating power vector; P is the control input of the heating power; is the error term, which represents the error between the predicted temperature and the reference temperature; is the transpose of the error term; N represents the number of future time steps;

[0048] Step 4: Pelican optimizes MPC;

[0049] Add the Pelican optimization algorithm to optimize the heating control strategy in the model predictive control (MPC) to ensure that energy efficiency is maximized while achieving the required temperature control accuracy;

[0050] The goal is to minimize the difference between the future predicted temperature and the target temperature and the energy consumption

[0051]

[0052] J is the objective function, P is the heating power, and λ is the regularization parameter for adjusting the power usage cost; T ref is the target temperature, T i k+jrepresents the predicted temperature, which is the temperature of the jth future time step predicted at the i-th spatial position and at the time step k; P k+j The heating power predicted for the jth future time step at time step k; n is the number of pelicans in the group;

[0053] Each pelican position corresponds to a heating strategy, whose fitness f(x i (t)) is calculated by the MPC model of the heating system as follows:

[0054]

[0055] Among them, f(x i (t)) is the fitness function, is the predicted temperature at time j in the future, T ref is the target temperature, which is used to balance the temperature control error and energy cost, represents the control input for the i-th spatial position and the j-th future time step; x i (t) represents the heating strategy of individual i at time t;

[0056] The speed and position of each pelican are updated according to the information sharing mechanism in the pelican group; the speed and position update rules are as follows:

[0057] v t+1 =w·v t +c1·r1·(p best -x t )+c2·r2·(g best -x t )

[0058] x t+1 =x t +v t+1

[0059] Among them, v t is the current speed at time t, x t is the current position at time t, p best It is the best position in the history of the Pelicans. best is the global optimal position, r1 and r2 are random numbers, c1 and c2 are learning factors, w is the inertia weight, v t+1 is the velocity at time t+1, x t+1 is the position at time t+1;

[0060] Step 5: Dynamic stirring control;

[0061] Nonlinear dynamic system theory applied to dynamic stirring control algorithms;

[0062] The flow and mixing behavior of polyethylene during stirring can be modeled using the Navier-Stokes equations, which are a set of nonlinear partial differential equations that describe fluid dynamics, as follows:

[0063] The Navier-Stokes equations describe the continuity and conservation of momentum of fluid motion;

[0064]

[0065] Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; is the rate of change of velocity with time; is the convection term, which indicates the change of velocity in space; p is the pressure field; μ is the dynamic viscosity coefficient, which describes the viscosity of the fluid; Laplace operator of the velocity field, representing the diffusion term; f is the external volume force;

[0066] Step 6: Fluid domain grid unit division;

[0067] The fluid domain is divided into grid cells, each of which interacts with neighboring cells through its interface;

[0068] The integrated form of the Navier-Stokes equations is applied to each mesh element V:

[0069]

[0070] Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; is the rate of change of velocity with time; is the convection term, which represents the change of velocity in space; p is the pressure field; μ is the dynamic viscosity coefficient, which describes the viscosity of the fluid; n is the unit normal vector on the control volume surface, is the boundary of the control volume; dV is the volume element; dA is the area element;

[0071] Use Gauss's theorem to convert the area integral into flux form:

[0072]

[0073] Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; p is the pressure field; μ is the dynamic viscosity coefficient, n is the unit normal vector on the control volume surface, is the boundary of the control volume; dA is the area element;

[0074] Step 7: SIMPLE algorithm solution;

[0075] By solving the discretized linear equation using the SIMPLE algorithm:

[0076] For each control volume, the velocity field is updated using the current pressure field estimate;

[0077]

[0078] Among them, a P The coefficient representing the center point; u P is the velocity of the center point; is the sum of neighboring cells or grid points; a nb is the coefficient of the neighboring point; u nb is the velocity of the neighboring point; b is the source term, including body force or other sources affecting the velocity; nb represents the neighboring point;

[0079] Through the above detailed implementation steps and formula derivation, the heating process and fluid behavior can be precisely controlled to ensure efficient operation of the system and consistency of product quality.

[0080] Compared with the prior art, the present invention has the following beneficial effects:

[0081] 1. In the present invention, through the designed polyethylene heating device and control method thereof, hot air is generated in the heating barrel during the heating process, which enters into the spiral heat-conducting pipe through the air inlet pipe and then preheats the polyethylene raw material in the preheating barrel, thereby accelerating the subsequent heating time of the polyethylene raw material in the heating barrel to achieve energy saving. When the rotating rod is adjusted in angle, the connecting block can realize the lifting and lowering of the movable rod, thereby driving the extrusion block to cyclically extrude the bottom of the heating barrel to make the heating barrel vibrate, so that the polyethylene raw material sticking to the inner wall of the heating barrel after heating is shaken off, thereby effectively solving the problem that the traditional polyethylene heating device is not convenient for preheating the polyethylene raw material and is not convenient for cleaning the residual raw material in the heating barrel during the heating process, resulting in waste of resources.

[0082] 2. Intelligent algorithms maximize energy efficiency by precisely adjusting heating power and stirring speed. In particular, the Pelican optimization algorithm is able to dynamically optimize power distribution throughout the heating process, which not only reduces energy waste but also ensures the best match between energy input and heating demand. By reducing overheating and excessive energy use, overall energy consumption is reduced, thereby reducing operating costs. Using model predictive control (MPC) technology, temperature changes during the heating process can be predicted and adjusted to ensure that the temperature is stable near the set target temperature. This precise temperature control not only improves product quality, but also reduces unstable material properties due to temperature fluctuations. Through dynamic stirring control, the intelligent algorithm is able to adjust stirring parameters such as speed and direction based on real-time feedback to address temperature non-uniformity issues within the heating barrel. Such adjustments make heating more uniform, avoid local overheating or insufficient heating, and further improve the quality and consistency of processed materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0084] Figure 2 For the present invention Figure 1 Schematic diagram of some internal structures;

[0085] Figure 3 For the present invention Figure 2 Schematic diagram of some internal structures;

[0086] Figure 4 For the present invention Figure 2 Schematic diagram of some structures;

[0087] Figure 5 For the present invention Figure 4 Structural cross-section diagram;

[0088] Figure 6 For the present invention Figure 3 Schematic diagram of some structures;

[0089] Figure 7 For the present invention Figure 5 Schematic diagram of the structure of part A;

[0090] Figure 8 This is a flow chart of the intelligent control algorithm of the present invention.

[0091] In the figure: 1, base; 2, support pad; 3, support column; 4, support frame; 5, telescopic rod; 6, reset spring; 7, connecting plate; 8, heating barrel; 801, first cavity; 9, discharge pipe; 10, feed pipe; 11, heating wire; 12, stirring motor; 13, support plate; 14, stirring shaft; 15, stirring rod; 16, air inlet pipe; 17, preheating barrel; 1701, second cavity; 18, spiral heat pipe; 19, air outlet pipe; 20, feed port; 21, vertical plate; 22, drive motor; 23, turntable; 24, movable rod; 25, rotating rod; 26, cylindrical block; 27, connecting block; 28, vertical rod; 29, extrusion block; 30, fixed rod; 31, round plate; 32, sleeve. DETAILED DESCRIPTION

[0092] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0093] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0094] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be a central element. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only.

[0095] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0096] For examples, see Figure 1-7 , the present invention provides a technical solution:

[0097] A polyethylene heating device comprises a base 1, support pads 2 are installed at the four corners of the bottom of the base 1, support columns 3 are installed at the four corners of the top of the base 1, a support frame 4 is installed on the top of the support columns 3, two groups of telescopic rods 5 are symmetrically installed at both ends of the top of the support frame 4, and reset springs 6 are installed on the outer ring surfaces of the telescopic rods 5. Connecting plates 7 are installed on the tops of the two groups of telescopic rods 5 at both ends of the top of the support frame 4, respectively, and a heating barrel 8 is installed between the outer sides of the connecting plates 7 and above the support frame 4, a discharge pipe 9 is installed at the bottom of the heating barrel 8, a feed pipe 10 is installed at one end of the inner top of the heating barrel 8, a first cavity 801 is opened inside the inner side wall of the heating barrel 8, a heating wire 11 is installed inside the first cavity 801, a stirring motor 12 is installed at the center of the inner top of the heating barrel 8, a support plate 13 is installed on the output shaft of the stirring motor 12, a stirring shaft 14 is installed at the three corners of the bottom of the support plate 13, and a plurality of stirring rods 15 are installed on the outer ring surface of the stirring shaft 14;

[0098] An air inlet pipe 16 is installed at one end of the top of the heating barrel 8, a preheating barrel 17 is installed at the center of the top of the heating barrel 8, a second cavity 1701 is opened inside the inner wall of the preheating barrel 17, a spiral heat conducting pipe 18 is installed inside the second cavity 1701, an air outlet pipe 19 is installed at one end of the outer ring surface of the preheating barrel 17, a feed port 20 is installed at the top of the preheating barrel 17, a vertical plate 21 is installed at the top of the base 1, a driving motor 22 is installed at one end of the wider side of the vertical plate 21, and a rotating shaft 26 is installed at one end of the side of the vertical plate 21 away from the driving motor 22. The turntable 23 has a movable rod 24 installed on the edge of the outer side surface, a rotating rod 25 is installed at one end of the movable rod 24, a cylindrical block 26 is installed inside the end of the rotating rod 25 away from the movable rod 24 and located on the vertical plate 21, a connecting block 27 is installed on the outside of the rotating rod 25, a vertical rod 28 is installed on the top of the connecting block 27, and an extrusion block 29 is installed on the top of the vertical rod 28. A number of fixed rods 30 are installed at equal intervals on the inner side wall of the support frame 4, and a circular plate 31 is installed together at one end of the fixed rods 30 away from the support frame 4, and a sleeve 32 is installed at the bottom of the circular plate 31.

[0099] Specifically, refer to Figure 3 One end of the air inlet pipe 16 passes through the interior of the heating barrel 8, and the end of the air inlet pipe 16 away from the heating barrel 8 passes through the interior of the first cavity 801 and is connected to one end of the spiral heat-conducting pipe 18. The end of the spiral heat-conducting pipe 18 away from the air inlet pipe 16 is connected to the external air outlet pipe 19, thereby ensuring that the hot air generated inside the heating barrel 8 during the heating process enters the interior of the spiral heat-conducting pipe 18 through the air inlet pipe 16. Since the water inside the first cavity 801 absorbs the heat of the hot air inside the spiral heat-conducting pipe 18, the polyethylene raw material inside the preheating barrel 17 is preheated, thereby accelerating the subsequent heating time of the polyethylene raw material inside the heating barrel 8, thereby achieving energy saving.

[0100] Furthermore, there are four groups of telescopic rods 5 and return springs 6, and the telescopic rods 5 and return springs 6 are symmetrically arranged at the two ends of the top of the support frame 4, and the connecting plate 7 and the heating barrel 8 are connected by bolts, thereby ensuring that the stability of the lifting and lowering of the heating barrel 8 is increased by the telescopic rods 5, and by arranging four groups of telescopic rods 5 and return springs 6, the heating barrel 8 is stably installed on the support frame 4.

[0101] Furthermore, the top of the feed pipe 10 passes through the heating barrel 8 and extends to the inner bottom of the preheating barrel 17, and the feed pipe 10 does not interfere with the support plate 13 during rotation. Solenoid valves are installed inside the feed pipe 10 and the discharge pipe 9, thereby ensuring that the heated polyethylene raw material can be discharged through the discharge pipe 9, and then the polyethylene raw material preheated inside the preheating barrel 17 can be poured into the heating barrel 8 through the feed pipe 10.

[0102] Furthermore, the output shaft of the driving motor 22 passes through the vertical plate 21 and is connected to the outside of the turntable 23, and one end of the movable rod 24 is rotatably connected to one end of the outer side surface of the turntable 23, thereby ensuring that the driving motor 22 drives the turntable 23 to rotate and synchronously drives the movable rod 24 to rotate.

[0103] Furthermore, one end of the movable rod 24 away from the turntable 23 is rotatably connected to one end of the rotating rod 25, the cylindrical block 26 is fixedly connected to the outside of the vertical plate 21, and the inside of one end of the rotating rod 25 is rotatably connected to the outer annular surface of the cylindrical block 26, thereby ensuring that when the turntable 23 drives the movable rod 24 to rotate, the rotating rod 25 is driven to adjust the angle with the cylindrical block 26 as the center.

[0104] Furthermore, one end of the top of the vertical rod 28 passes through the inner wall of the sleeve 32 and then passes through the circular plate 31 to be connected to the bottom of the extrusion block 29, and the outer annular surface of the vertical rod 28 is slidably connected to the inner wall of the sleeve 32 and the inside of the circular plate 31, thereby ensuring that the stability of the vertical rod 28 in lifting and lowering is increased through the sliding connection between the vertical rod 28, the circular plate 31 and the sleeve 32.

[0105] For details, please refer to Figure 1 , Figure 4 , Figure 5 and Figure 7The bottom end of the connecting block 27 is rotatably connected to the outside of the rotating rod 25, and the top end of the connecting block 27 is rotatably connected to the bottom end of the vertical rod 28, thereby ensuring that the rotating rod 25 can lift and lower the vertical rod 28 through the connecting block 27 when adjusting the angle, thereby driving the extrusion block 29 to cyclically extrude the bottom of the heating barrel 8, and while squeezing the heating barrel 8 to rise, stretching the telescopic rod 5 and the return spring 6, when the vertical rod 28 descends, the restriction of the return spring 6 is released, driving the heating barrel 8 to descend, thereby vibrating the heating barrel 8, so that the polyethylene sticking to the inner wall of the heating barrel 8 after heating is shaken away and then discharged through the discharge pipe 9.

[0106] The present invention also discloses a control method for a polyethylene heating device, which specifically comprises the following steps:

[0107] Step 1: First, inject polyethylene raw materials into the heating barrel 8 and the preheating barrel 17. The raw materials inside the heating barrel 8 can be heated by the heating wire 11, and the stirring motor 12 is started. The stirring motor 12 drives the support plate 13 to rotate and simultaneously drives the multiple groups of stirring shafts 14 to rotate. The polyethylene raw materials heated inside the heating barrel 8 are stirred by the stirring rod 15, so that the polyethylene raw materials are mixed more evenly, thereby accelerating the heating speed.

[0108] Step 2: During the heating process, hot air is generated inside the heating barrel 8 and enters the interior of the spiral heat pipe 18 through the air inlet pipe 16. Since the water inside the first cavity 801 absorbs the heat of the hot air inside the spiral heat pipe 18, the polyethylene raw material inside the preheating barrel 17 is preheated, thereby accelerating the subsequent heating time of the polyethylene raw material inside the heating barrel 8, thereby achieving energy saving. The heated polyethylene raw material can be discharged through the discharge pipe 9, and then the preheated polyethylene raw material inside the preheating barrel 17 can be poured into the heating barrel 8 through the feed pipe 10.

[0109] Step three: The turntable 23 is driven by the driving motor 22 to rotate, thereby synchronously driving the movable rod 24 to rotate. When the turntable 23 drives the movable rod 24 to rotate, it drives the rotating rod 25 to adjust the angle around the cylindrical block 26. When adjusting the angle, the rotating rod 25 can realize the lifting and lowering of the vertical rod 28 through the connecting block 27. The sliding connection between the vertical rod 28, the circular plate 31 and the sleeve 32 increases the stability of the lifting and lowering of the vertical rod 28, thereby driving the extrusion block 29 to cyclically extrude the bottom of the heating barrel 8, and stretching the telescopic rod 5 and the reset spring 6 while squeezing the heating barrel 8 to rise. When the vertical rod 28 descends, the restriction of the reset spring 6 is released, driving the heating barrel 8 to descend, thereby vibrating the heating barrel 8, so that the polyethylene raw material sticking to the inner wall of the heating barrel 8 after heating is shaken off, and then discharged through the discharge pipe 9, thereby avoiding waste of resources.

[0110] like Figure 8, the present invention also discloses intelligent control of a polyethylene heating device through an intelligent control algorithm, and the specific process is as follows;

[0111] Step 1: Sensor installation and data collection;

[0112] Point temperature sensors: platinum resistance thermometers (RTDs), installed at the inlet, center, and outlet of the heating barrel to monitor temperature distribution;

[0113] Power meter: monitors the actual power consumed by the heating element and is usually installed on the power line to accurately measure the heating power;

[0114] Flow rate sensor: Ultrasonic flow meter, installed in the heating barrel to monitor the flow rate of polyethylene;

[0115] Torque sensor: Installed on the stirring device, it measures the torque during stirring to evaluate stirring load and viscosity changes;

[0116] Pressure sensor: installed at the appropriate position of the heating barrel to monitor the pressure changes of polyethylene during processing;

[0117] Ambient temperature and humidity sensors: monitor the temperature and humidity of the work area environment to help adjust the control strategy to adapt to environmental changes;

[0118] Step 2: System modeling;

[0119] A physical model describing the heat transfer process of polyethylene in a heating barrel is established; the model is based on the heat conduction equation:

[0120]

[0121] Where T is temperature, t is time, x is position, α is the thermal diffusivity of the material, β is a coefficient related to the power of the heating device, and P(t) is the heating power at time t;

[0122] Discretize the above continuous-time physical model in space and time;

[0123] Spatial discretization:

[0124]

[0125] Where T represents temperature, x represents position, Δx represents the change in position; i is the spatial index, which represents the discretized position; k is the time step, which represents the number of time steps after discretization; T i k represents the temperature at the i-th spatial position and the k-th time step; represents the temperature at the i+1th spatial position and the kth time step; represents the temperature at the i-1th spatial position and the kth time step; represents the finite difference of the second-order spatial derivative;

[0126] Time discretization:

[0127]

[0128] Among them, T represents temperature, t represents time, i is the spatial index, which represents the discretized position; k is the time step, which represents the number of time steps after discretization; Δt represents the change in time, T i k represents the temperature at the i-th spatial position and the k-th time step; T i k+1 represents the temperature at the ith spatial position and the k+1th time step; represents the first-order time derivative;

[0129] Using the finite difference method for spatial derivatives and the Euler method for temporal derivatives, the discretized spatial and temporal derivatives are substituted into the original equations to obtain the combined discretization:

[0130]

[0131] Among them, i is the spatial index, which indicates the discretized position; k is the time step, which indicates the number of time steps after discretization; Δt indicates the change in time, Δx indicates the change in position; T indicates temperature, t indicates time, x indicates position, α is the thermal diffusivity of the material, and β is a coefficient related to the power of the heating device; T i k represents the temperature at the i-th spatial position and the k-th time step; T i k+1 represents the temperature at the ith spatial position and the k+1th time step; represents the temperature at the i+1th spatial position and the kth time step; represents the temperature at the i-1th spatial position and the kth time step; P k represents the heating power at the kth time step;

[0132] Step 3: Convert the discretized model into state space;

[0133] Convert the discrete model to state-space form:

[0134] T k+1 =AT k +BP k

[0135] Among them, T k+1 represents the temperature vector at the k+1th time step; T krepresents the temperature vector at the kth time step, A and B are the corresponding system matrix and input matrix; P k represents the heating power vector at the kth time step;

[0136] At each time step, MPC determines the optimal heating power P by solving the following optimization problem;

[0137]

[0138] Among them, T k+j represents the predicted temperature, which is the temperature of the jth future time step predicted at time step k; j represents the index of the predicted time step; is the target temperature, Q is the weight matrix used to adjust the weight of the temperature error, R is the weight matrix used to adjust the weight of the control input, P T represents the transpose of the heating power vector; P is the control input of the heating power; is the error term, which represents the error between the predicted temperature and the reference temperature; is the transpose of the error term; N represents the number of future time steps;

[0139] Step 4: Pelican optimizes MPC;

[0140] Add the Pelican optimization algorithm to optimize the heating control strategy in the model predictive control (MPC) to ensure that energy efficiency is maximized while achieving the required temperature control accuracy;

[0141] The goal is to minimize the difference between the future predicted temperature and the target temperature and the energy consumption

[0142]

[0143] J is the objective function, P is the heating power, and λ is the regularization parameter for adjusting the power usage cost; T ref is the target temperature, T i k+j represents the predicted temperature, which is the temperature of the jth future time step predicted at the i-th spatial position and at the time step k; P k+j The heating power predicted for the jth future time step at time step k; n is the number of pelicans in the group;

[0144] Each pelican position corresponds to a heating strategy, whose fitness f(x i (t)) is calculated by the MPC model of the heating system as follows:

[0145]

[0146] Among them, f(x i (t)) is the fitness function, is the predicted temperature at time j in the future, T ref is the target temperature, which is used to balance the temperature control error and energy cost, represents the control input for the i-th spatial position and the j-th future time step; x i (t) represents the heating strategy of individual i at time t;

[0147] The speed and position of each pelican are updated according to the information sharing mechanism in the pelican group; the speed and position update rules are as follows:

[0148] v t+1 =w·v t +c1·r1·(p best -x t )+c2·r2·(g best -x t )

[0149] x t+1 =x t +v t+1

[0150] Among them, v t is the current speed at time t, x t is the current position at time t, p best It is the best position in the history of the Pelicans. best is the global optimal position, r1 and r2 are random numbers, c1 and c2 are learning factors, w is the inertia weight, v t+1 is the velocity at time t+1, x t+1 is the position at time t+1;

[0151] Step 5: Dynamic stirring control;

[0152] Nonlinear dynamic system theory applied to dynamic stirring control algorithms;

[0153] The flow and mixing behavior of polyethylene during stirring can be modeled using the Navier-Stokes equations, which are a set of nonlinear partial differential equations that describe fluid dynamics, as follows:

[0154] The Navier-Stokes equations describe the continuity and conservation of momentum of fluid motion;

[0155]

[0156] Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; is the rate of change of velocity with time; is the convection term, which indicates the change of velocity in space; p is the pressure field; μ is the dynamic viscosity coefficient, which describes the viscosity of the fluid; Laplace operator of the velocity field, representing the diffusion term; f is the external volume force;

[0157] Step 6: Fluid domain grid unit division;

[0158] The fluid domain is divided into grid cells, each of which interacts with neighboring cells through its interface;

[0159] The integrated form of the Navier-Stokes equations is applied to each mesh element V:

[0160]

[0161] Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; is the rate of change of velocity with time; is the convection term, which represents the change of velocity in space; p is the pressure field; μ is the dynamic viscosity coefficient, which describes the viscosity of the fluid; n is the unit normal vector on the control volume surface, is the boundary of the control volume; dV is the volume element; dA is the area element;

[0162] Use Gauss's theorem to convert the area integral into flux form:

[0163]

[0164] Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; p is the pressure field; μ is the dynamic viscosity coefficient, n is the unit normal vector on the control volume surface, is the boundary of the control volume; dA is the area element;

[0165] Step 7: SIMPLE algorithm solution;

[0166] By solving the discretized linear equation using the SIMPLE algorithm:

[0167] For each control volume, the velocity field is updated using the current pressure field estimate;

[0168]

[0169] Among them, a P The coefficient representing the center point; u P is the velocity of the center point; is the sum of neighboring cells or grid points; a nb is the coefficient of the neighboring point; u nbis the velocity of the neighboring point; b is the source term, including body force or other sources affecting the velocity; nb represents the neighboring point;

[0170] Through the above detailed implementation steps and formula derivation, the heating process and fluid behavior can be precisely controlled to ensure efficient operation of the system and consistency of product quality.

[0171] Numerical Examples

[0172] Initial conditions: Without optimization, the entire heating barrel was set to a uniform 1000 watts. Due to uneven heating, the temperature varied from 170°C to 190°C from one end of the barrel to the other. The energy consumed per minute was higher because the entire system was running at high power.

[0173] The optimized target temperature is 180°C. Maximize energy efficiency and reduce energy waste. Achieve a more uniform temperature distribution by optimizing the stirring mechanism.

[0174] Optimization process: Use POA to optimize the heating power configuration to minimize energy consumption and achieve the target temperature. Use the MPC strategy to calculate the optimal temperature response and power adjustment every minute for the next 10 minutes. 50 pelicans are randomly initialized, each representing a possible heating power sequence. In 50 iterations, each pelican updates its position and speed according to its fitness to find the best heating power configuration.

[0175] Optimization results: Optimal heating power configuration: The optimized heating power configuration shows that the power is increased in the center area of ​​the heating barrel (1200 watts) and reduced at both ends (800 watts) to achieve more uniform heating.

[0176] Temperature distribution: The optimized temperature is more uniform, and most areas are stable at 180℃±2℃.

[0177] Energy consumption: By dynamically adjusting the heating power, the overall energy consumption is reduced by about 10%, improving energy efficiency.

[0178] Dynamic stirring control

[0179] Before optimization: The stirring speed and mode were fixed, resulting in overheating in some areas and low temperatures in some areas.

[0180] After optimization: Adjust the stirring speed and depth according to the real-time temperature feedback to ensure that the material in the entire heating barrel is heated evenly. Increase the stirring intensity in the lower temperature area and reduce the stirring in the higher temperature area.

[0181] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A polyethylene heating device, comprising a base (1), characterized in that: Support pads (2) are installed at the four corners of the bottom of the base (1), support columns (3) are installed at the four corners of the top of the base (1), and a support frame (4) is installed on the top of the support columns (3). Two groups of telescopic rods (5) are symmetrically installed at both ends of the top of the support frame (4), and the outer ring surfaces of the telescopic rods (5) are installed with return springs (6). The tops of the two groups of telescopic rods (5) at both ends of the top of the support frame (4) are respectively installed with connecting plates (7), and a heating barrel (8) is installed between the outer sides of the connecting plates (7) and above the support frame (4). The heating barrel ( 8) is installed with a discharge pipe (9) at the bottom, a feed pipe (10) is installed at one end of the inner top of the heating barrel (8), a first cavity (801) is opened inside the inner wall of the heating barrel (8), a heating wire (11) is installed inside the first cavity (801), a stirring motor (12) is installed at the center of the inner top of the heating barrel (8), a support plate (13) is installed on the output shaft of the stirring motor (12), stirring shafts (14) are installed at the three corners of the bottom of the support plate (13), and a plurality of stirring rods (15) are installed on the outer ring surface of the stirring shaft (14); An air inlet pipe (16) is installed at one end of the top of the heating barrel (8), a preheating barrel (17) is installed at the center of the top of the heating barrel (8), a second cavity (1701) is opened inside the inner wall of the preheating barrel (17), a spiral heat conducting pipe (18) is installed inside the second cavity (1701), an air outlet pipe (19) is installed at one end of the outer ring surface of the preheating barrel (17), a feed port (20) is installed at the top of the preheating barrel (17), a vertical plate (21) is installed at the top of the base (1), a driving motor (22) is installed at one end of the wider side of the vertical plate (21), and a turntable (23) is installed at one end of the side of the vertical plate (21) away from the driving motor (22). ), a movable rod (24) is installed at the edge of the outer side surface of the rotating disk (23), a rotating rod (25) is installed at one end of the movable rod (24), a cylindrical block (26) is installed inside the end of the rotating rod (25) away from the movable rod (24) and located on the vertical plate (21), a connecting block (27) is installed outside the rotating rod (25), a vertical rod (28) is installed on the top of the connecting block (27), and an extrusion block (29) is installed on the top of the vertical rod (28), a plurality of fixed rods (30) are installed at equal intervals on the inner side wall of the support frame (4), a circular plate (31) is installed together at one end of the fixed rod (30) away from the support frame (4), and a sleeve (32) is installed at the bottom of the circular plate (31).

2. The polyethylene heating device according to claim 1, characterized in that: A total of four groups of telescopic rods (5) and return springs (6) are provided, and the telescopic rods (5) and return springs (6) are symmetrically arranged at the top ends of the support frame (4), and the connecting plate (7) and the heating barrel (8) are connected by bolts.

3. The polyethylene heating device according to claim 1, characterized in that: The top of the feed pipe (10) passes through the heating barrel (8) and then extends to the inner bottom of the preheating barrel (17), and the feed pipe (10) does not interfere with the support plate (13) during rotation. Solenoid valves are installed inside the feed pipe (10) and the discharge pipe (9).

4. The polyethylene heating device according to claim 1, characterized in that: One end of the air inlet pipe (16) passes through the interior of the heating barrel (8), and the end of the air inlet pipe (16) away from the heating barrel (8) passes through the interior of the first cavity (801) and is connected to one end of the spiral heat-conducting pipe (18), and the end of the spiral heat-conducting pipe (18) away from the air inlet pipe (16) is connected to an external air outlet pipe (19).

5. The polyethylene heating device according to claim 1, characterized in that: The output shaft of the driving motor (22) passes through the vertical plate (21) and is connected to the outside of the rotating disk (23), and one end of the movable rod (24) is rotatably connected to one end of the outer side surface of the rotating disk (23).

6. The polyethylene heating device according to claim 1, characterized in that: The end of the movable rod (24) away from the turntable (23) is rotatably connected to one end of the rotating rod (25), the cylindrical block (26) is fixedly connected to the outside of the vertical plate (21), and the inside of one end of the rotating rod (25) is rotatably connected to the outer ring surface of the cylindrical block (26).

7. The polyethylene heating device according to claim 1, characterized in that: The bottom end of the connection block (27) is rotationally connected to the outside of the rotating rod (25), and the top end of the connection block (27) is rotationally connected to the bottom end of the vertical rod (28).

8. The polyethylene heating device according to claim 1, characterized in that: One end of the top of the vertical rod (28) passes through the inner wall of the sleeve (32) and then passes through the circular plate (31) to be connected to the bottom of the extrusion block (29), and the outer annular surface of the vertical rod (28) is slidably connected to the inner wall of the sleeve (32) and the inside of the circular plate (31).

9. The control method of a polyethylene heating device according to any one of claims 1 to 8, characterized in that: The specific steps include: Step 1: First, polyethylene raw materials are injected into the interior of the heating barrel (8) and the preheating barrel (17), and the raw materials in the heating barrel (8) are heated by the heating wire (11), and the stirring motor (12) is started. The stirring motor (12) drives the support plate (13) to rotate and simultaneously drives the multiple groups of stirring shafts (14) to rotate, and the polyethylene raw materials heated in the heating barrel (8) are stirred by the stirring rod (15), so that the polyethylene raw materials are mixed more evenly, thereby accelerating the heating speed; Step 2: During the heating process, hot air is generated inside the heating barrel (8) and enters the interior of the spiral heat-conducting tube (18) through the air inlet pipe (16). Since the water inside the first cavity (801) absorbs the heat of the hot air inside the spiral heat-conducting tube (18), the polyethylene raw material inside the preheating barrel (17) is preheated, thereby accelerating the subsequent heating time of the polyethylene raw material inside the heating barrel (8), thereby achieving energy saving. The heated polyethylene raw material can be discharged through the discharge pipe (9), and then the polyethylene raw material preheated inside the preheating barrel (17) can be poured into the interior of the heating barrel (8) through the feed pipe (10); Step 3: The rotating disk (23) is driven by the driving motor (22) to rotate and synchronously drive the movable rod (24) to rotate. When the rotating disk (23) drives the movable rod (24) to rotate, the rotating rod (25) is driven to adjust the angle with the cylindrical block (26) as the center. When the rotating rod (25) is adjusted, the vertical rod (28) can be lifted and lowered through the connecting block (27). The vertical rod (28) is connected with the circular plate (31) and the sleeve (32) through sliding, thereby increasing the stability of the vertical rod (28) in lifting and lowering. The extrusion block (29) is driven to cyclically extrude the bottom of the heating barrel (8). When the heating barrel (8) is lifted, the telescopic rod (5) and the return spring (6) are stretched. When the vertical rod (28) is lowered, the restriction of the return spring (6) is released, driving the heating barrel (8) to lower, thereby generating vibration on the heating barrel (8), so that the polyethylene raw material adhering to the inner wall of the heating barrel (8) after heating is shaken off and then discharged through the discharge pipe (9), thereby avoiding waste of resources.

10. The control method of the polyethylene heating device according to claim 9, characterized in that: It also includes intelligently controlling the polyethylene heating device through an intelligent control algorithm, and the specific process is as follows; Step 1: Sensor installation and data collection; Point temperature sensors: platinum resistance thermometers (RTDs), installed at the inlet, center, and outlet of the heating barrel to monitor temperature distribution; Power meter: monitors the actual power consumed by the heating element and is usually installed on the power line to accurately measure the heating power; Flow rate sensor: Ultrasonic flow meter, installed in the heating barrel to monitor the flow rate of polyethylene; Torque sensor: Installed on the stirring device, it measures the torque during stirring to evaluate stirring load and viscosity changes; Pressure sensor: installed at the appropriate position of the heating barrel to monitor the pressure changes of polyethylene during processing; Ambient temperature and humidity sensors: monitor the temperature and humidity of the work area environment to help adjust the control strategy to adapt to environmental changes; Step 2: System modeling; A physical model describing the heat transfer process of polyethylene in a heating barrel is established; the model is based on the heat conduction equation: Where T is temperature, t is time, x is position, α is the thermal diffusivity of the material, β is a coefficient related to the power of the heating device, and P(t) is the heating power at time t; Discretize the above continuous-time physical model in space and time; Spatial discretization: Where T represents temperature, x represents position, Δx represents the change in position; i is the spatial index, which represents the discretized position; k is the time step, which represents the number of time steps after discretization; T i k represents the temperature at the i-th spatial position and the k-th time step; represents the temperature at the i+1th spatial position and the kth time step; represents the temperature at the i-1th spatial position and the kth time step; represents the finite difference of the second-order spatial derivative; Time discretization: Among them, T represents temperature, t represents time, i is the spatial index, which represents the discretized position; k is the time step, which represents the number of time steps after discretization; Δt represents the change in time, T i k represents the temperature at the i-th spatial position and the k-th time step; T i k+1 represents the temperature at the ith spatial position and the k+1th time step; represents the first-order time derivative; Using the finite difference method for spatial derivatives and the Euler method for temporal derivatives, the discretized spatial and temporal derivatives are substituted into the original equations to obtain the combined discretization: Among them, i is the spatial index, which indicates the discretized position; k is the time step, which indicates the number of time steps after discretization; Δt indicates the change in time, Δx indicates the change in position; T indicates temperature, t indicates time, x indicates position, α is the thermal diffusivity of the material, and β is a coefficient related to the power of the heating device; T i k represents the temperature at the i-th spatial position and the k-th time step; T i k +1 represents the temperature at the ith spatial position and the k+1th time step; represents the temperature at the i+1th spatial position and the kth time step; represents the temperature at the i-1th spatial position and the kth time step; P k represents the heating power at the kth time step; Step 3: Convert the discretized model into state space; Convert the discrete model to state-space form: T k+1 =AT k +Bp k Among them, T k+1 represents the temperature vector at the k+1th time step; T k represents the temperature vector at the kth time step, A and B are the corresponding system matrix and input matrix; P k represents the heating power vector at the kth time step; At each time step, the model predictive control MPC determines the optimal heating power P by solving the following optimization problem; Among them, T k+j represents the predicted temperature, which is the temperature of the jth future time step predicted at time step k; j represents the index of the predicted time step; is the target temperature, Q is the weight matrix used to adjust the weight of the temperature error, R is the weight matrix used to adjust the weight of the control input, P T represents the transpose of the heating power vector; P is the control input of the heating power; is the error term, which represents the error between the predicted temperature and the reference temperature; is the transpose of the error term; N represents the number of future time steps; Step 4: Pelican optimizes MPC; Add the Pelican optimization algorithm to optimize the heating control strategy in the model predictive control MPC to ensure maximum energy efficiency while achieving the required temperature control accuracy; The goal is to minimize the difference between the future predicted temperature and the target temperature and the energy consumption J is the objective function, P is the heating power, and λ is the regularization parameter for adjusting the power usage cost; T ref is the target temperature, T i k+j represents the predicted temperature, which is the temperature of the jth future time step predicted at the i-th spatial position and at the time step k; P k +j The heating power predicted for the jth future time step at time step k; n is the number of pelicans in the group; Each pelican position corresponds to a heating strategy, whose fitness f(x i (t)) is calculated by the MPC model of the heating system as follows: Among them, f(x i (t)) is the fitness function, is the predicted temperature at time j in the future, T ref is the target temperature, which is used to balance the temperature control error and energy cost, represents the control input for the i-th spatial position and the j-th future time step; x i (t) represents the heating strategy of individual i at time t; The speed and position of each pelican are updated according to the information sharing mechanism in the pelican group; the speed and position update rules are as follows: v t+1 =w·v t +c1·r1·(p best -x t )+c2·r2·(g best -x t ) x t+1 =x t +v t+1 Among them, v t is the current speed at time t, x t is the current position at time t, p best It is the best position in the history of the Pelicans. best is the global optimal position, r1 and r2 are random numbers, c1 and c2 are learning factors, w is the inertia weight, v t+1 is the velocity at time t+1, x t+1 is the position at time t+1; Step 5: Dynamic stirring control; Nonlinear dynamic system theory applied to dynamic stirring control algorithms; The flow and mixing behavior of polyethylene during stirring is described using the Navier-Stokes equations, which are a set of nonlinear partial differential equations that describe fluid dynamics. They are as follows: The Navier-Stokes equations describe the continuity and conservation of momentum of fluid motion; Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; is the rate of change of velocity with time; is the convection term, which indicates the change of velocity in space; p is the pressure field; μ is the dynamic viscosity coefficient, which describes the viscosity of the fluid; Laplace operator of the velocity field, representing the diffusion term; f is the external volume force; Step 6: Fluid domain grid unit division; The fluid domain is divided into grid cells, each of which interacts with neighboring cells through its interface; The integrated form of the Navier-Stokes equations is applied to each mesh element V: Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; is the rate of change of velocity with time; is the convection term, which represents the change of velocity in space; p is the pressure field; μ is the dynamic viscosity coefficient, which describes the viscosity of the fluid; n is the unit normal vector on the control volume surface, is the boundary of the control volume; dV is the volume element; dA is the area element; Use Gauss's theorem to convert the area integral into flux form: Where u is the velocity vector field; represents the gradient of the velocity vector field u; ρ is the density of the fluid; p is the pressure field; μ is the dynamic viscosity coefficient, n is the unit normal vector on the control volume surface, is the boundary of the control volume; dA is the area element; Step 7: SIMPLE algorithm solution; By solving the discretized linear equation using the SIMPLE algorithm: For each control volume, the velocity field is updated using the current pressure field estimate; Among them, a P The coefficient representing the center point; u P is the velocity of the center point; is the sum of neighboring cells or grid points; a nb is the coefficient of the neighboring point; u nb is the velocity of the neighboring point; b is the source term, including body force or other sources affecting the velocity; nb represents the neighboring point; Through the above detailed implementation steps and formula derivation, the heating process and fluid behavior can be precisely controlled to ensure efficient operation of the system and consistency of product quality.

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