A dynamic regulation method for temperature field of a casting mold in a casting process

Abstract

The application relates to the technical field of foundry process control, and specifically discloses a dynamic regulation method for a mold temperature field in a casting process, which divides the mold and the adjacent casting area into basic thermal control units, establishes a coupling prediction model of the mold wall and the casting double-side temperature field, and combines the measured temperature to perform online correction, and then takes three coupling quantitative indexes, i.e., a hot spot risk value, a feeding channel connectivity coefficient and a shell safety coefficient, as a joint criterion, dynamically reconfigures each basic thermal control unit into a hot spot inhibition group, a feeding channel protection group and a buffer stabilization group in each control period, and applies differentiated temperature control strategies such as pulse cooling, micro-heating and interval maintenance in the solidification stage switching process, so as to realize real-time dynamic regulation of the mold temperature field, and solve the problems that the traditional preset temperature control parameters and fixed partition adjustment mode cannot dynamically regulate the mold temperature field according to the real-time solidification state in the casting process, and cannot simultaneously consider hot spot inhibition and feeding channel protection.

Description

Technical Field

[0001] This application relates to the field of casting process control technology, and specifically discloses a method for dynamic control of the temperature field of the mold during the casting process. Background Technology

[0002] Casting is a forming process in which molten metal is poured into a mold cavity and then cooled and solidified to obtain a casting. It is widely used in equipment manufacturing, automotive, aerospace and other fields. During the casting process, the mold temperature field directly affects the filling state of the molten metal, the solidification sequence of different areas of the casting, and the final casting quality. For castings with complex structures, uneven wall thickness distribution, or obvious local hot spots, the reasonable control of the mold temperature field is a key process to suppress casting defects such as shrinkage cavities, porosity, and uneven microstructure.

[0003] For the aforementioned castings, existing mold temperature field control methods generally involve pre-setting the cooling, heating, and heat-holding positions or local heat-conducting structures of the mold based on the casting structure and experience before casting. After pouring, the mold temperature is adjusted through overall cooling, local spray cooling, local heating, or zoned temperature control to ensure the casting solidifies according to a predetermined solidification sequence. Furthermore, existing technologies also include a control method that pre-tunes the process parameters of the cooling or heating loops based on initial temperature field simulation results, and executes temperature control commands according to a predetermined parameter sequence after pouring begins. While this control method introduces a certain degree of process parameter pre-optimization, it is essentially still an open-loop or semi-open-loop control method primarily based on "pre-set temperature control parameters + fixed zone adjustment."

[0004] However, in the actual casting process, the temperature changes and solidification state inside the casting will change continuously with the changes in the filling stage, the initial solidification stage and the final solidification stage. The interface heat transfer state between each area of ​​the mold and the casting, the heat conduction state between each area inside the casting, the connectivity state of the feeding channels and the development state of the local shell are not fixed, but evolve dynamically with time and space.

[0005] Therefore, the above-mentioned methods, which mainly rely on preset temperature control parameters or fixed zone adjustment, often make it difficult to dynamically control the mold temperature field according to the real-time solidification state during the casting process, resulting in the following problems: Due to the fixed zoning, temperature control commands are difficult to synchronize with the actual migration and development of hot spots, which can easily lead to uneven temperature field distribution in local areas and difficulty in effectively eliminating hot spots; Because the real-time connectivity status of the feeding channel is not determined when the strong cooling command is applied, the feeding channel is prone to premature failure, which in turn cuts off the feeding path from the surrounded liquid phase area to the feeding source area such as riser, ingate or riser pipe. Since the thickness development status and temperature drop rate of the local shell were not determined when the strong cooling command was applied, it is easy to cause the local shell to be too thin, the temperature drop to be too fast, or the thermal stress to be abnormal. The lack of a stage-switching mechanism that matches the solidification process makes it difficult to stably guide the final solidification position of the remaining liquid phase region to the preset feeding and trapping zone, resulting in uncontrolled positioning of the final solidification zone. These problems ultimately lead to shrinkage cavities, porosity, uneven microstructure, and even localized cracking in the castings, affecting the yield and mechanical properties of the castings.

[0006] Furthermore, existing solutions also include attempts to introduce thermocouples or infrared temperature measuring devices for real-time monitoring of the mold temperature and to adjust the cooling or heating circuits accordingly. However, such feedback adjustment methods typically use only single-point temperature or regional average temperature as criteria, failing to comprehensively characterize the formation and development of hot spots from multiple dimensions such as the degree of overheating, final solidification time deviation, temperature gradient in the feeding direction, and isolation tendency. They also fail to simultaneously assess the connectivity of the feeding channels and the safety of the local shell, thus still struggling to resolve the inherent contradictions between "eliminating hot spots" and "protecting the feeding channels," and between "eliminating hot spots" and "maintaining shell safety" during the casting process.

[0007] This invention provides a method for dynamically controlling the temperature field of the mold during the casting process, in order to solve the above-mentioned problems. Summary of the Invention

[0008] The purpose of this invention is to solve the problems that traditional methods, which mainly rely on preset temperature control parameters and fixed zone adjustment, are difficult to dynamically control the mold temperature field according to the real-time solidification state during the casting process, and are also difficult to take into account both hot spot suppression and feeding channel protection.

[0009] To achieve the above objectives, the basic solution of the present invention provides a method for dynamic control of the mold temperature field during the casting process, comprising the following steps: Step A1: Construct a control system consisting of a temperature measurement unit, a calculation control unit, and an execution unit. Divide the mold and its adjacent casting area into several basic thermal control units. Each basic thermal control unit is bound to at least one temperature measurement point and at least one execution loop. Establish a feeding path from each basic thermal control unit to the feeding source area. Step A2: Establish a heat dissipation equilibrium prediction model for the equivalent temperature of the mold wall and an apparent heat capacity method prediction model for the equivalent temperature of adjacent castings, and perform online correction of the prediction results based on the measured temperature. Step A3: Based on the corrected equivalent temperature of adjacent castings, calculate the solid fraction and expected final solidification time of each basic thermal control unit, establish the target solidification path according to the path length from each basic thermal control unit to the feeding source area, and obtain the final solidification time deviation. Step A4: Based on the state variables obtained in Steps A2 and A3, calculate the thermal node risk value, the compensating channel connectivity coefficient, and the shell safety factor for each basic thermal control unit. Step A5: Based on the hot spot risk value, the shrinkage channel connectivity coefficient and the shell safety factor, the basic thermal control unit is dynamically reconstructed and grouped, and each basic thermal control unit is divided into the hot spot suppression group, the shrinkage channel protection group or the buffer stability group, and differentiated collaborative temperature control is implemented for the three types of control groups. Step A6: Switch the solidification stage according to the global average solid fraction until all remaining liquid phase basic thermal control units fall into the preset feeding and capture zone.

[0010] Furthermore, in step A1, the area adjacent to the riser, ingate, or riser pipe is defined as the feeding source area; For any basic thermal control unit, if there are multiple feasible compensation paths to the compensation source region, the compensation channel connectivity coefficient corresponding to each feasible compensation path is calculated in each control cycle, and the feasible compensation path with the largest current compensation channel connectivity coefficient is selected as the effective compensation path of the basic thermal control unit in that control cycle.

[0011] Furthermore, in step A2, the heat dissipation balance prediction model for the equivalent temperature of the mold wall is constructed based on four types of heat exchange processes: heat transfer inside the mold wall between adjacent basic thermal control units, interfacial heat exchange between the mold wall and the casting, input of the heating circuit, and output of the cooling circuit. The heating input is the product of the heating control quantity and the maximum output capacity of the heating circuit, and the cooling output is the product of the cooling control quantity and the maximum output capacity of the cooling circuit. Both the heating control quantity and the cooling control quantity take values ​​between 0 and 1. The apparent heat capacity method prediction model for the equivalent temperature of adjacent castings incorporates the latent heat of solidification into the effective heat capacity, so that the adjacent area of ​​the casting takes the liquid phase specific heat capacity in the liquid phase region, the superposition value of the ratio of the sensible heat specific heat capacity of the solid-liquid two-phase region to the latent heat of solidification and the liquid-solid phase temperature difference in the solid phase region, and the solid phase specific heat capacity in the solid phase region. Furthermore, the heat dissipation balance prediction model of the equivalent temperature of the mold wall and the apparent heat capacity prediction model of the equivalent temperature of the adjacent casting are coupled and iterated through the interface heat transfer term between the mold wall and the casting.

[0012] Furthermore, in step A2, for the i-th basic thermal control unit, a set of temperature measurement points corresponding to it is established. The weight of each temperature measurement point to the basic thermal control unit is assigned according to the reciprocal distance weighting method. The measured temperature of all normal temperature measurement points in the set is weighted and averaged using the weight. The weighted average result is then fused with the predicted wall temperature according to the correction coefficient to obtain the corrected wall temperature. The equivalent temperature of the adjacent casting adopts the mold wall-casting linkage correction method, that is, the product of the mold wall correction amount and the transfer correction coefficient is superimposed on the predicted value of the equivalent temperature of the adjacent casting. The mold wall correction amount is the difference between the mold wall correction temperature and the mold wall prediction temperature. For any temperature measurement point, if the temperature jump exceeds the preset jump threshold for two consecutive sampling cycles, or the temperature deviation from other temperature measurement points under the same basic thermal control unit exceeds the preset deviation threshold, then the temperature measurement point is determined to be an abnormal temperature measurement point and is blocked from the corresponding temperature measurement point set in the current control cycle.

[0013] Furthermore, in step A3, a target solidification path is established based on the path length from each basic thermal control unit to the feeding source area. The target final solidification time of each basic thermal control unit in the target solidification path satisfies the condition that the basic thermal control unit with a longer path from the feeding source area completes solidification earlier, and the basic thermal control unit with a shorter path from the feeding source area completes solidification later, so that the casting solidifies in the order of the far end solidifying first and the feeding source end solidifying later. The estimated final solidification time of the i-th basic thermal control unit is estimated based on the difference between the equivalent temperature and solidus temperature of its current adjacent casting and the absolute value of the current cooling rate. When the cooling rate is zero, positive, or too small, a preset minimum positive number is used as the lower limit of the cooling rate to avoid the occurrence of singular values ​​in the estimated final solidification time. The final setting time deviation of the i-th basic thermal control unit is the difference between the expected final setting time and the target final setting time of the basic thermal control unit. When the final setting time deviation is greater than zero, it indicates that the basic thermal control unit has a late setting trend relative to the target solidification path and has the potential to form an isolated hot spot.

[0014] Furthermore, in step A4, the first Thermal risk value of each basic thermal control unit From superheat component Final condensation weight Temperature gradient component in the feeding direction and the tendency to isolate Jointly determined: ; In the formula, ; The superheat component reflects the degree of superheating of the current equivalent temperature of the adjacent casting relative to the preset superheat reference temperature of the basic thermal control unit. The final solidification lag component reflects the degree of delayed solidification of the basic thermal control unit relative to the target solidification path; The temperature gradient component in the feeding direction reflects the degree to which the equivalent temperature of the adjacent casting of the next basic thermal control unit, which is one step ahead of the basic thermal control unit along its effective feeding path, is higher than the equivalent temperature of the adjacent casting of the basic thermal control unit. The isolation tendency component is the arithmetic mean of the solid fractions of all first-order adjacent basic thermal control units of the basic thermal control unit. Furthermore, the superheat component, the final stagnation component, and the temperature gradient component in the feeding direction are all normalized by preset reference values ​​and truncated between 0 and 1.

[0015] Furthermore, in step A4, the first The connectivity coefficient of the compensation channel of each basic thermal control unit A composite metric combining the weakest link and overall connectivity is used: ; in, For the intermediate basic thermal control unit on the effective feeding path of the basic thermal control unit Local connectivity This represents the minimum local connectivity among all paths on the effective path reduction path. This represents the product of the local connectivity of each element on the effective simplification path. Geometric mean The number of intermediate basic thermal control units included in the effective compensation path. This represents the weighting coefficient for the weakest link.

[0016] Furthermore, in step A4, the first Shell safety factor of each basic thermal control unit It is composed of a shell thickness factor and a mold wall rate drop factor; The shell thickness factor is obtained by truncating the ratio of the shell thickness formed by the product of the number of layers at the basic thermal control unit that continuously satisfy the solidity not less than the preset shell determination solidity threshold and the grid step size, to the preset shell safety thickness threshold. The wall velocity drop factor is obtained by truncating the ratio of the absolute value of the rate of change of the equivalent temperature of the wall in the basic thermal control unit within adjacent sampling periods to a preset local velocity drop safety threshold for the wall. Furthermore, for non-boundary type basic thermal control units, .

[0017] Furthermore, in step A5, all basic thermal control units are first screened for thermal node risk values ​​that are not less than a preset thermal node risk threshold. Furthermore, the basic thermal control unit with a local maximum thermal risk value relative to its adjacent basic thermal control unit is designated as the hotspot center, and the hotspot centers are then classified and control groups are constructed according to the following rules: when , and At that time, the corresponding basic thermal control unit is assigned to the set of hot spot centers that can be directly suppressed; when but or At that time, the corresponding basic thermal control unit is assigned to the protective hotspot center set. and These are the preset compensation channel connectivity threshold and the preset shell security threshold, respectively. For each directly suppressable hot spot center, a hot spot suppression group is constructed; for each hot spot center to the effective shrinkage path from the shrinkage source area and its adjacent area, a shrinkage channel protection group is constructed; and the remaining basic thermal control units are used to construct a buffer stabilization group. For the basic thermal control unit in the thermal suppression group, a suppression permission factor is introduced. Gating the cooling control quantity: ; In the formula, Time to take ,when Time to take In other cases, take In itself, when or When the corresponding threshold is just crossed, Approaching zero, only when and When all are significantly higher than the corresponding threshold, Close to 1; For the basic thermal control unit in the buffer stabilization group, the upper and lower limits of the buffer zone temperature are preset. When the mold wall temperature is higher than the upper limit, a small amount of cooling is applied, and when it is lower than the lower limit, a small amount of heating is applied. When it is within the buffer zone, the current control state is maintained.

[0018] Furthermore, in step A6, the global average solid fraction is defined as the arithmetic mean of the solid fractions of all basic thermal control units; When the global average solid fraction is less than the preset first switching threshold During the filling and early shell prevention stage, the cooling control quantity of all basic thermal control units is set to a lower upper limit. When the same basic thermal control unit meets the judgment conditions of both the thermal block suppression group and the shrinkage channel protection group, it is processed according to the shrinkage channel protection group first. When the global average solid fraction is not less than the preset first switching threshold And less than the preset second switching threshold At this time, during the solidification gradient establishment stage, the focus is on suppressing areas with high thermal risk values ​​and maintaining the temperature gradient in the feeding direction to increase the dynamic reconfiguration frequency of the control group. When the global average solid fraction is not less than the preset second switching threshold At this time, during the final solidification capture stage, the remaining liquid phase region is guided to the preset feeding capture zone, which is located near the riser, ingate or riser pipe; When all remaining liquid phase thermal control units fall into the preset feeding and capture zone, the dynamic reconfiguration control process ends and the insulation termination procedure begins. and This is the preset threshold for switching between solidification stages.

[0019] The principle and effect of this basic scheme are as follows: 1. Compared with the prior art, the present invention divides the mold and its adjacent casting area into basic thermal control units, and binds temperature measurement points, execution loops and feeding paths to each basic thermal control unit, establishing a three-element binding relationship of "temperature measurement-execution-feeding". On this basis, a coupled prediction model of the temperature field on both sides of the mold wall and the casting is constructed and corrected online by combining the measured temperature. It can simultaneously reflect the thermal diffusion process on the mold side and the phase change solidification process on the casting side, providing an accurate state basis for subsequent dynamic control. It solves the problem that the traditional method of mainly relying on preset temperature control parameters and fixed zone adjustment is difficult to dynamically control the temperature field of the mold according to the real-time solidification state during the casting process.

[0020] 2. Compared with existing technologies, this invention proposes three coupled quantitative indicators: hot spot risk value, shrinkage channel connectivity coefficient, and shell safety factor. These indicators comprehensively evaluate the current state of each basic thermal control unit from three complementary dimensions: "whether suppression is needed," "whether suppression is allowed," and "whether suppression is safe." This expands hot spot identification from a single temperature criterion to a composite criterion, enabling a more accurate characterization of the formation and development trend of isolated hot spots. Simultaneously, it evaluates the connectivity of the shrinkage path and the development state of the local shell, fundamentally resolving the inherent contradictions between "eliminating hot spots" and "protecting shrinkage channels," as well as between "eliminating hot spots" and "maintaining shell safety."

[0021] 3. Compared with the prior art, the present invention dynamically reconstructs and groups the basic thermal control unit based on the above three quantitative indicators in each control cycle, and applies differentiated and coordinated temperature control strategies such as pulsed cooling, micro-heating and heat preservation, and buffer zone maintenance to the thermal block suppression group, the feeding channel protection group, and the buffer stabilization group, respectively. Combined with the solidification stage switching mechanism based on the global average solid fraction, the control strategy is dynamically matched with the solidification process, and the final solidification position of the remaining liquid phase region is stably guided to the preset feeding capture zone. This significantly reduces the probability of casting defects such as shrinkage cavities, shrinkage porosity, uneven structure and local cracking, and improves the yield and mechanical properties of castings. Attached Figure Description

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

[0023] Figure 1 A flowchart of a method for dynamic control of the mold temperature field during the casting process, as proposed in an embodiment of this application, is shown. Detailed Implementation

[0024] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0025] A method for dynamic control of the mold temperature field during casting, implementing, for example... Figure 1 As shown, it includes the following steps: Step A1: Construct a control system consisting of a temperature measurement unit, a calculation control unit, and an execution unit. Divide the mold and its adjacent casting area into several basic thermal control units. Each basic thermal control unit is bound to at least one temperature measurement point and at least one execution loop. Establish a feeding path from each basic thermal control unit to the feeding source area. Step A2: Establish a heat dissipation equilibrium prediction model for the equivalent temperature of the mold wall and an apparent heat capacity method prediction model for the equivalent temperature of adjacent castings, and perform online correction of the prediction results based on the measured temperature. Step A3: Based on the corrected equivalent temperature of adjacent castings, calculate the solid fraction and expected final solidification time of each basic thermal control unit, establish the target solidification path according to the path length from each basic thermal control unit to the feeding source area, and obtain the final solidification time deviation. Step A4: Based on the state variables obtained in Steps A2 and A3, calculate the thermal node risk value, the compensating channel connectivity coefficient, and the shell safety factor for each basic thermal control unit. Step A5: Based on the hot spot risk value, the shrinkage channel connectivity coefficient and the shell safety factor, the basic thermal control unit is dynamically reconstructed and grouped, and each basic thermal control unit is divided into the hot spot suppression group, the shrinkage channel protection group or the buffer stability group, and differentiated collaborative temperature control is implemented for the three types of control groups. Step A6: Switch the solidification stage according to the global average solid fraction until all remaining liquid phase basic thermal control units fall into the preset feeding and capture zone.

[0026] The following is a detailed description of each step. This embodiment uses the low-pressure casting process of a complex aluminum alloy casting with uneven thickness and hot spots as an example, but the invention is not limited thereto.

[0027] Step A1: Construct a control system consisting of a temperature measurement unit, a calculation control unit, and an execution unit. Divide the mold and its adjacent casting area into several basic thermal control units. Each basic thermal control unit is bound to at least one temperature measurement point and at least one execution loop. Establish a feeding path from each basic thermal control unit to the feeding source area.

[0028] This step forms the physical and topological foundation of the entire dynamic control method. Its purpose is to establish a control system with real-time sensing, computation, and execution capabilities. Through the rational division of the mold and its adjacent casting areas, it provides the topological structure and data channels for subsequent steps: A2 (dual temperature field prediction), A3 (solidification state calculation), A4 (calculation of the three coupled quantitative indices), and A5 (dynamic reconstruction of the control group). Specifically, it includes the following sub-steps: Step A101: Coordinated configuration of the temperature measurement unit, the calculation and control unit, and the execution unit.

[0029] A control system is constructed by a temperature measurement unit, a computational control unit, and an execution unit. The temperature measurement unit is used to collect temperature information of different areas of the mold in real time and transmit the temperature data to the computational control unit. The computational control unit is used to calculate and update the temperature field of the mold and the solidification state of the casting in real time based on the temperature measurement data and the preset model, perform various index calculations, and issue temperature control commands. The execution unit is used to implement cooling, heating, or heat preservation adjustment of different areas of the mold according to the temperature control commands. The three units communicate in real time through wired or wireless industrial fieldbus, forming a closed loop of "perception-decision-execution".

[0030] The temperature measurement unit includes several thermocouples embedded inside the mold and several infrared temperature measuring devices located on the outside of the mold. The thermocouples are positioned in candidate hotspot areas, thin-walled areas prone to early solidification, feeding channels, and areas near risers, ingates, or riser pipes. Candidate hotspot areas are those identified based on the three-dimensional structure analysis of the casting and previous trial casting experience, which are prone to generating isolated liquid phase zones. The execution unit includes several independently adjustable cooling circuits and several independently adjustable heating circuits. The cooling circuits employ air cooling, water cooling, or mist cooling, while the heating circuits use electric heating rods, heating elements, or induction heating. Each cooling and heating circuit can be continuously adjusted via duty cycle commands issued by the computational control unit. The computational control unit uses an industrial controller, industrial computer, or programmable logic controller in conjunction with a host computer or equivalent data processing equipment.

[0031] Furthermore, before control begins, the three-dimensional structural parameters of the casting, wall thickness distribution data, feeding source location, thermal properties of the mold material (including density, specific heat capacity, and thermal conductivity), thermal properties of the casting material (including density, specific heat capacity, liquidus temperature, solidus temperature, and latent heat of solidification), and maximum output capacity parameters of each execution loop are input into the computational control unit. and The initial temperature of the mold, the pouring temperature, and the ambient temperature are input into the computation control unit as initial boundary conditions to ensure that subsequent model calculations have clear starting conditions.

[0032] Step A102: Divide the basic thermal control unit and establish the binding relationship between temperature measurement and execution loop.

[0033] Based on the casting's outline, wall thickness distribution, hot spot location, feeding source location, and execution circuit arrangement, the mold and the adjacent area of ​​the casting that directly exchanges heat with the mold are divided into several basic thermal control units. The i-th basic thermal control unit is denoted as . When partitioning, it is preferable to use a finer partitioning granularity for hot spot candidate regions, thin-walled regions, and shrinkage channel regions, and a coarser partitioning granularity for transition regions, in order to balance computational efficiency and control accuracy.

[0034] Furthermore, each basic thermal control unit establishes a corresponding relationship with at least one temperature measurement point and at least one execution loop, thereby forming a ternary binding relationship of "temperature measurement point - basic thermal control unit - execution loop". If a basic thermal control unit corresponds to multiple temperature measurement points, the weighted result is taken as the real-time temperature measurement input of the basic thermal control unit according to the distance reciprocal weighting method described in step A203; if a basic thermal control unit corresponds to multiple execution loops, multiple execution loops are allowed to superimpose and adjust the same basic thermal control unit, and the control quantity of each loop is issued by the control law for the control group to which the basic thermal control unit belongs in step A6.

[0035] In this embodiment, the mold is divided into 24 basic thermal control units, of which the hot spot candidate area is divided into 8 basic thermal control units, the thin-walled area is divided into 6 basic thermal control units, the feeding channel area is divided into 6 basic thermal control units, and the remaining transition area is divided into 4 basic thermal control units. The temperature measurement unit is equipped with 12 thermocouples and 4 infrared temperature measurement points, and the execution unit is equipped with 12 cooling circuits and 8 heating circuits.

[0036] Step A103: Define the shrinkage source region, establish the shrinkage path, and select an effective shrinkage path in scenarios with multiple shrinkage sources.

[0037] To support the establishment of the target solidification path in subsequent step A302 and the calculation of the feeding channel connectivity coefficient in step A402, the area adjacent to the riser, ingate, or riser pipe is defined as the feeding source region; for any basic thermal control unit Establish a feeding path to the feeding source region, the feeding path being established by the basic thermal control unit. Starting from the casting, the path passes through several intermediate basic thermal control units and finally connects to the feeding source region. The specific direction of the feeding path can be determined comprehensively based on the three-dimensional structure of the casting, the layout of the mold flow channels, and the solidification sequence obtained from previous numerical simulations.

[0038] Furthermore, for castings with multiple feeding sources (e.g., risers and ingates simultaneously) or multiple feasible feeding paths to the feeding source region within the same basic thermal control unit, since the real-time connectivity of different feasible feeding paths dynamically changes with the solidification process, the feeding channel connectivity coefficient corresponding to each feasible feeding path is calculated according to the method described in step A402 within each control cycle. The feasible feeding path with the largest current feeding channel connectivity coefficient is selected as the effective feeding path for that basic thermal control unit within that control cycle. The effective feeding path will serve as the temperature gradient component in the feeding direction in step A401. and the tendency to isolate This provides the basis for calculations, thereby avoiding deviations in compensation determination caused by fixed path selection.

[0039] Through the construction of the control system and the division of basic thermal control units completed in step A1, the entire mold and its adjacent casting area are organized into a discrete network consisting of N basic thermal control units. Each basic thermal control unit has a clear temperature measurement channel, execution channel and feeding channel in the topology, thus providing a complete data interface and execution interface for the real-time calculation and control in subsequent steps A2 to A6.

[0040] Step A2: Establish a heat dissipation equilibrium prediction model for the equivalent temperature of the mold wall and an apparent heat capacity prediction model for the equivalent temperature of adjacent castings, and perform online correction of the prediction results based on the measured temperature.

[0041] The purpose of this step is to establish a coupled prediction model for two temperature fields—the mold side (equivalent temperature field of the mold wall) and the casting side (equivalent temperature field of adjacent castings)—based on the discrete network constructed in step A1. The prediction results are then corrected online using measured temperatures to obtain the real-time equivalent temperature of the mold wall for each basic thermal control unit. Equivalent temperature of adjacent castings The real-time values ​​of these two temperature fields are direct inputs for the calculation of solidification state quantities in step A3 and the calculation of the three coupled quantitative indicators in step A4. Considering that it is usually inconvenient to directly embed temperature measuring points in the adjacent areas of the casting, this step also sets up a mold wall-casting linkage correction mechanism and an abnormal temperature measuring point identification and shielding mechanism to ensure the robustness of the entire control process.

[0042] Specifically, it includes the following sub-steps: Step A201: Prediction of heat dissipation balance of equivalent temperature of the mold wall.

[0043] For the Basic thermal control unit The equivalent temperature of its mold wall is defined as The evolution of the mold wall equivalent temperature is driven by four types of heat exchange processes: heat exchange between adjacent basic thermal control units through conduction within the mold wall, heat exchange between the mold wall and the casting through interfacial contact, heating input injected into the mold wall by the heating circuit, and cooling heat carried away from the mold wall by the cooling circuit. Based on the principle of thermal balance, these four processes are uniformly incorporated into a discrete iterative format, and the mold wall equivalent temperature is predicted by the following formula: ; In the formula, Indicates the sampling period number. The sampling period is Basic thermal control unit The equivalent heat capacity of the wall, Basic thermal control unit With adjacent basic thermal control unit The equivalent thermal conductivity of the wall between the two Basic thermal control unit The heat transfer at the interface between the mold and the casting. Basic thermal control unit In the Heating input within each sampling period Basic thermal control unit In the The cooling zone heat within each sampling period.

[0044] The heating input and the cooling zone heat respectively satisfy the following: ; ; In the formula, For the control quantity of the heating circuit, For the control variables of the cooling circuit, both take values ​​between 0 and 1. and The maximum output capacity of the heating circuit and the cooling circuit are respectively pre-entered in step A101.

[0045] This sub-step integrates the multi-source heat exchange process on the casting side into an explicit discrete iterative format, providing a basis for subsequent control variables. , The calculations provide a basis for predicting the mold wall side, while the format retains the relationship with the casting side temperature. Coupling terms This enables it to form a coupled iteration with the casting-side prediction model in step A202.

[0046] Step A202: Prediction of the equivalent temperature of adjacent castings using the apparent heat capacity method.

[0047] For the Basic thermal control unit The corresponding adjacent region of the casting is defined as having an equivalent temperature of 1. It is important to note that the casting material undergoes a solid-liquid phase transition during solidification. The latent heat released during this phase transition significantly alters the temperature evolution characteristics of adjacent regions of the casting. If the same heat dissipation equilibrium scheme as in step A201 is simply applied, significant prediction errors will result due to the nonlinearity of temperature evolution in the phase transition region. Therefore, this sub-step employs the apparent heat capacity method to incorporate the latent heat into the effective heat capacity, enabling the temperature evolution of adjacent regions of the casting to be solved using an explicit discrete iterative scheme.

[0048] Specifically, the apparent heat capacity of the casting material in the liquid phase, solid-liquid two-phase region, and solid phase region. They are defined as follows: when hour, ; when hour, ; when hour, ; In the formula, For liquid phase heat capacity, For solid phase heat capacity, This refers to the sensible heat and specific heat capacity of the solid-liquid two-phase region. For latent heat of solidification, Liquidus temperature This is the solidus temperature. The apparent heat capacity of the solid-liquid two-phase region is also mentioned. The value is significantly greater than the relative heat capacity of a pure solid or pure liquid phase, reflecting the "decelerating" effect of latent heat release on temperature evolution during the phase transition.

[0049] The equivalent temperature of adjacent castings is then predicted using the following discrete iterative scheme: ; In the formula, For the density of the casting material, Basic thermal control unit The corresponding equivalent volume, Basic thermal control unit With adjacent basic thermal control unit The equivalent thermal conductivity of the adjacent area between the castings is... This refers to the apparent heat capacity.

[0050] Through the coupled iteration of steps A201 and A202, the equivalent temperature field of the mold wall and the equivalent temperature field of the adjacent casting are represented by the interface heat transfer term. The coupling link influences each other, thus enabling the simultaneous reflection of the thermal diffusion process on the mold side and the phase transformation solidification process on the casting side. In this embodiment, for aluminum alloy castings, The temperature is set at 615℃. The temperature was set at 555℃, and the sampling period was... Set to 1 second.

[0051] Step A203: Online correction of measured temperature based on distance reciprocal weighting and linkage correction between mold wall and casting.

[0052] Since the prediction models given in steps A201 and A202 are open-loop recursive formats based on physical parameters, prediction errors will accumulate over a long period due to factors such as model parameter errors, boundary condition deviations, and unmodeled disturbances. Therefore, performing online correction of the prediction results based on measured temperature in each sampling period is a necessary step to ensure the long-term stable operation of the entire control process.

[0053] Specifically, the corresponding basic thermal control unit A set of corresponding temperature measurement points is established, which is determined by the "temperature measurement point-basic thermal control unit" binding relationship established in step A102. Considering that different temperature measurement points are at different distances from the geometric center of the basic thermal control unit, and therefore have different representativeness of the temperature state of that unit, a distance-inverse weighted method is used to allocate the weight of each temperature measurement point. The m-th temperature measurement point corresponds to the basic thermal control unit... The weights satisfy: ; In the formula, Basic thermal control unit With the Mapping distance between temperature measurement points Basic thermal control unit With the The mapping distance between temperature measuring points can be determined based on the Euclidean distance between the geometric center of the basic thermal control unit and the location where the temperature measuring points are buried.

[0054] Then the basic thermal control unit The wall correction temperature satisfies: ; In the formula, The wall temperature is the one predicted in step A201. This refers to the actual measured temperature at the corresponding temperature measurement point. For correction factors, Its value reflects the relative degree of confidence in the predicted value and the measured weighted value. The closer the value is to 1, the more trust the model prediction is placed in it; the closer it is to 0, the more trust the measured value is placed in it.

[0055] Furthermore, since it is usually inconvenient to directly embed temperature measuring points within the adjacent areas of castings (the high-temperature molten environment places stringent requirements on sensor lifespan and measurement accuracy), a mold wall-casting linkage correction method is adopted for the equivalent temperature of adjacent castings. ; In the formula, The equivalent temperature of the adjacent castings is predicted in step A202. This is a correction factor for the temperature correction of the mold wall that is transferred to the casting side.

[0056] The value of reflects the proportion of the propagation of the disturbance on the mold wall side to the casting side through interfacial heat transfer. Its physical meaning is that when the mold wall prediction in step A201 shows a deviation of Δ and is corrected by actual measurement, the temperature on the casting side coupled with it should also be proportional. Synchronous corrections are performed to maintain the coupling consistency between the two temperature fields.

[0057] Correction coefficient and correction factor The settings can be adjusted based on historical data of similar castings, results of previous trial castings, or results of numerical simulations, and different values ​​are allowed at different solidification stages to adapt to the differences in the coupling characteristics of the dual temperature fields at each stage.

[0058] Step A204: Identification, shielding, and replacement of abnormal temperature measurement points.

[0059] In industrial casting environments, thermocouples may experience reading drift, jumps, or even complete failure due to high-temperature erosion, loose connections, or damaged cables. Infrared temperature measuring devices may also exhibit abnormal readings due to oxidation of the mold surface, oil mist contamination, or field-of-view obstruction. Directly incorporating these abnormal readings into the weighted calculation in step A203 will cause the corrected temperature to deviate significantly from the actual value, leading to distortion in the judgment of the three coupled quantitative indicators in subsequent step A4, ultimately resulting in erroneous temperature control commands. Therefore, before proceeding to the weighted calculation in step A203, it is necessary to identify outliers in the measured temperatures at each measuring point.

[0060] Specifically, anomaly identification is performed using dual criteria for any temperature measurement point: the first criterion is a time-domain jump criterion, which checks for temperature jumps in two consecutive sampling periods at that temperature measurement point. Exceeding the preset transition threshold If the measured temperature at this point is suspected to be abnormal, the measurement point is considered abnormal. The second criterion is the spatial deviation criterion; if the measured temperature deviation between this temperature measurement point and other temperature measurement points under the same basic thermal control unit exceeds a preset deviation threshold... If the temperature at any given point triggers at least one of the two criteria, that point is officially identified as an abnormal temperature measurement point within the current control cycle.

[0061] For measuring points identified as abnormal temperature points, remove them from the basic thermal control unit within the current control cycle. The corresponding temperature measurement points are temporarily masked and will not participate in the distance reciprocal weighted calculation in step A203. The weights of the remaining normal temperature measurement points are... Renormalize according to the remaining normal temperature measurement points; if all temperature measurement points under a basic thermal control unit are determined to be abnormal temperature measurement points, then take the mold wall predicted temperature of that basic thermal control unit. Directly used as the correction temperature (i.e., equivalent to using) Set to 1), and at the same time, mark the temperature measurement channel status of the basic thermal control unit as "temperature measurement degradation" and report it to the operation and control unit to trigger the predetermined sensor abnormality handling procedure, such as retrieving the temperature measurement data of the adjacent basic thermal control unit for alternative estimation, or automatically reducing the upper limit of the control quantity of the relevant execution loop to avoid issuing aggressive commands when the temperature measurement information is unreliable.

[0062] This step ensures that the overall control process remains stable even under conditions such as sensor drift, connection abnormalities, or partial failures, demonstrating industrial feasibility and robustness. At this point, step A2 synchronously provides the corrected equivalent wall temperature for each basic thermal control unit. Equivalent temperature of adjacent castings This serves as the status input for subsequent steps A3 and A4.

[0063] Step A3: Based on the corrected equivalent temperature of adjacent castings, calculate the solid fraction and expected final solidification time of each basic thermal control unit, establish the target solidification path according to the path length from each basic thermal control unit to the feeding source area, and obtain the final solidification time deviation.

[0064] The purpose of this step is to determine the equivalent temperature of adjacent castings after correction obtained in step A2. The solidification state variables (including solid fraction, cooling rate, and expected final solidification time) of each basic thermal control unit are calculated. Combined with the feeding path length established in step A1, a target solidification path is established, thereby obtaining the final solidification time deviation, which measures the speed of solidification progress of each basic thermal control unit relative to the target solidification sequence. These state variables will serve as the core inputs for calculating the three coupled quantitative indicators in step A4, especially the final solidification time deviation. Will directly participate in the hot season risk value Mid-term condensation post-concentration fraction The calculation of solid fraction Participation in isolation tendency component and the connectivity coefficient of the compensation channel and shell safety factor The calculation includes the following sub-steps: Step A301: Calculation of solid fraction, cooling rate and expected final solidification time.

[0065] Solidity is a core physical quantity for measuring the local solidification progress of a casting. Its value ranges from 0 to 1, where 0 represents a completely liquid phase and 1 represents a completely solid phase. Based on the equivalent temperature of adjacent castings obtained in step A2... And the liquidus temperature entered in step A1 and solidus temperature The basic thermal control unit is calculated using linear interpolation. The corresponding solid fraction : when hour, ; when hour, ; when hour, .

[0066] For those that are still in a partially solidified state (i.e.) The basic thermal control unit further calculates its cooling rate based on the equivalent temperature of adjacent castings in two adjacent sampling cycles, as shown in the following expression: ; Indicates the basic thermal control unit The equivalent temperature of adjacent castings at the first Discrete cooling rates within each sampling period, with positive values ​​indicating heating up, negative values ​​indicating cooling down, and zero values ​​indicating that the temperature is temporarily stable.

[0067] in, A positive value indicates that the basic thermal control unit is heating up (if a temperature rebound occurs), a negative value indicates that the basic thermal control unit is cooling down, and zero indicates that the temperature is temporarily stable.

[0068] Furthermore, assuming the current cooling rate remains essentially stable over a short period of time, the basic thermal control unit... Reaching solidus temperature The remaining time required can be estimated by dividing the difference between the equivalent temperature of the current adjacent casting and the solidus temperature by the absolute value of the cooling rate. Therefore, the basic thermal control unit... The expected final setting time satisfies: when hour, ; when hour, ; In the formula, At the current sampling time, To prevent extremely small positive numbers with a denominator of zero.

[0069] It should be noted that, The physical meaning is: when the equivalent temperature of an adjacent casting is still higher than the solidus line but abnormal conditions occur such as zero cooling rate, positive cooling rate (i.e., a temperature rebound phenomenon), or excessively small absolute value, then... This serves as a lower limit for the cooling rate to avoid outliers (such as division by zero or negative values) in the expected final solidification time. When such situations occur, the corresponding basic thermal control unit... This will be estimated as a large finite value, thus manifesting as a significant final setting time deviation in step A302, which is precisely the final setting lag component in subsequent step A401. The "late condensation" characteristic to be captured.

[0070] Step A302: Establish the target solidification path and calculate the final solidification time deviation.

[0071] To ensure that the casting solidifies in the order of "solidification at the far end first, followed by solidification at the feeding source end," thereby guaranteeing that the feeding channel remains connected throughout the solidification process and that the remaining liquid phase region continuously receives replenishment from the feeding source region, a target solidification path needs to be established that matches the path length from each basic thermal control unit to the feeding source region. The physical basis of this target solidification path is that the basic thermal control unit farther from the feeding source should complete solidification earlier, and the basic thermal control unit closer to the feeding source should complete solidification later, thus forming a directional solidification that gradually progresses from the far end to the feeding source end.

[0072] Specifically, based on the effective compensation path established in step A103, a basic thermal control unit is set. The path length to the source region is The maximum path length in all basic thermal control units is (i.e., the path length of the basic thermal control unit farthest from the compensation source), then the basic thermal control unit The target final setting time is satisfied: ; In the formula, The earliest target final setting time corresponds to the basic thermal control unit furthest from the feeding source region in the casting, reflecting the temporal starting point of the solidification process from the far end. The final solidification time gradient coefficient reflects the tightness of the target solidification sequence. The larger the value, the greater the required difference in final setting time between the far and near ends, corresponding to a more stringent directional setting process. The smaller the value, the closer the target final setting time of each basic thermal control unit is, corresponding to a more relaxed directional solidification. and The specific value can be adjusted based on historical data of similar castings, results of previous trial castings, or results of numerical simulation.

[0073] Thus, the basic thermal control unit is obtained. Final setting time deviation: ; Final setting time deviation It is a measure of the basic thermal control unit The key indicator relative to the speed of the target solidification path has the following physical meaning: when At that time, it indicates the basic thermal control unit The predicted final setting time is later than its target final setting time, showing a tendency to set later relative to the target solidification path, which may lead to the formation of isolated hot spots. Therefore, the calculation of the hot spot risk value needs to be emphasized in step A4; when At that time, it indicates the basic thermal control unit Solidification is completed exactly in the target solidification sequence; when At that time, it indicates the basic thermal control unit The predicted final setting time is earlier than its target final setting time, showing a tendency to set prematurely relative to the target solidification path. This may cause the feeding channel to fail prematurely. Therefore, in step A4, the connectivity coefficient of the feeding channel needs to be checked. This should be reported.

[0074] At this point, step A3 provides the real-time solids content for each basic thermal control unit. Cooling rate Expected final setting time Target final freezing time and final setting time deviation This serves as the direct input for calculating the three coupled quantitative indicators in the subsequent step A4.

[0075] Step A4: Based on the state variables obtained in Steps A2 and A3, calculate the thermal risk value, the compensating channel connectivity coefficient, and the shell safety factor for each basic thermal control unit.

[0076] This step is the core of the entire dynamic control method for generating criteria. Its purpose is to calculate the three coupled quantitative indicators—the thermal stagnation risk value—based on the dual temperature field state obtained in step A2 and the solidification state quantity obtained in step A3. Compensation channel connectivity coefficient and shell safety factor The three coupled quantitative indicators comprehensively evaluate the current state of each basic thermal control unit from three complementary dimensions: "whether suppression is needed," "whether suppression is allowed," and "whether suppression is safe." These indicators together form the basis for the dynamic reconfiguration of the control group in subsequent step A5. Specifically, this includes the following sub-steps: Step A401: Hot spot risk value Multi-component weighted calculation.

[0077] Hot spot risk value Used to quantify the basic thermal control unit The possibility of forming isolated hot spots depends on the superheat component. Final condensation weight Temperature gradient component in the feeding direction and the tendency to isolate The four components are determined together. They characterize the formation and development trend of hot spots from four complementary dimensions: "whether it is currently overheated", "whether it will condense late in the future", "whether the shrinkage direction gradient is correct" and "whether it has been solidified and surrounded". This expands hot spot identification from a single temperature criterion to a composite criterion.

[0078] Specifically, the superheat component is used to reflect the basic thermal control unit. The degree of overheating of the current adjacent casting's equivalent temperature relative to the preset overheating reference temperature satisfies: ; In the formula, To preset the superheat reference temperature, Indicates when Time to take ,when Time to take In other cases, take The details will not be elaborated upon further below.

[0079] The physical meaning of this component is: when Significantly higher than hour, A value close to 1 indicates severe overheating in the region. Close to or below hour, A value close to 0 indicates that overheating in this region is not significant.

[0080] The final condensation component is used to reflect the basic thermal control unit. The degree of late setting relative to the target solidification path is determined by the final setting time deviation obtained in step A302. Based on preset benchmark value After normalization, the following condition is met: ; The physical meaning of this component is: when When it is large, A value close to 1 indicates severe late condensation in the region. When less than or equal to 0, It is truncated to 0 and does not contribute to the late condensation penalty for hot spot risk value.

[0081] The temperature gradient component along the feeding direction is used to reflect the basic thermal control unit. Is the temperature gradient along the effective feeding path pointing towards the feeding source correct? Ideally, the temperature of the next basic thermal control unit along the feeding direction should be higher than the temperature of the current basic thermal control unit, thereby guiding the liquid metal to continuously replenish from the feeding source to the current basic thermal control unit. This component satisfies: ; In the formula, Basic thermal control unit The equivalent temperature of the adjacent casting corresponding to the next basic thermal control unit along the effective feeding path pointing to the feeding source. This is the preset temperature gradient reference value for the feeding direction.

[0082] It should be noted that, A larger value indicates a more accurate temperature gradient in the feeding direction (i.e., higher downstream temperature and smoother feeding flow), therefore... In the synthesis of Participation in the form of, i.e. The smaller the value (the more inverse or weaker the gradient), the greater its contribution to the hot spot risk value.

[0083] The isolation tendency component is used to reflect the basic thermal control unit. The degree to which it is surrounded by solidified units satisfies: ; In the formula, Indicates the basic thermal control unit The set of all first-order adjacent basic thermal control units, for Any first-order adjacent basic thermal control unit solid fraction, for The total number of first-order adjacent basic thermal control units. The statistical range of this component covers... All first-order neighbors in three-dimensional space, and only the temperature gradient in the compensation direction is described. They are physically independent and complementary.

[0084] The physical meaning of this component is: when When it is close to 1, it indicates The surrounding adjacent basic thermal control units have basically solidified. In an isolated liquid phase state "surrounded by a solid phase", isolated heat nodes are easily formed. When it is close to 0, it indicates The surrounding area is still in a liquid phase or early solidification state, and the tendency to isolate is not significant.

[0085] Combining the above four components, the risk value of the hot spot satisfy: ; In the formula, , , , These are the weighting coefficients, and In this embodiment, it is preferred to take... , , , , The temperature is set at 580℃. Set to 30 seconds. The temperature is set to 20℃. The weighting coefficients and benchmark values ​​can be adjusted based on historical data of similar castings, previous trial casting results, or numerical simulation results.

[0086] Step A402: Compensate for channel connectivity coefficients The weakest link - overall connectivity composite metric.

[0087] Compensation channel connectivity coefficient Used to characterize the basic thermal control unit Whether the effective feeding path to the feeding source region remains effectively connected. Failure of the feeding path may be caused by excessively high local solidity at a critical location on the path (a typical "bottleneck" blockage), or by simultaneous partial degradation at multiple locations on the path (a typical "gradual decay" degradation). To account for both of these different failure modes, this sub-step adopts a combined measurement method of the weakest link and overall connectivity.

[0088] Specifically, for any intermediate basic thermal control unit on the effective compensation path Define its local connectivity. for: ; In the formula, The solid fraction threshold for failure of the compensation channel reflects the solid fraction threshold corresponding to the failure of the compensation flow. The connectivity decay index reflects the rate at which local connectivity decreases as the solid fraction increases.

[0089] when solid fraction Approaching or exceeding hour, A rapid decay to near zero indicates that the location has essentially lost its ability to compensate for flow. far below hour, A value close to 1 indicates that the flow capacity at this location is good. The larger the value, the better. Approaching The more rapid the decay, the more it reflects the nonlinear characteristic that the compensation channel fails rapidly once it reaches the critical point.

[0090] Furthermore, the basic thermal control unit The connectivity coefficient of the compensation channel satisfies: ; In the formula, This represents the minimum local connectivity among the intermediate basic thermal control units along the effective compensation path, reflecting the "barrel effect"—a blockage at any critical point is considered a failure of the compensation process. This represents the product of the local connectivity of each element on the effective simplification path. Its geometric mean reflects "overall degradation"—simultaneous partial degradation at multiple locations will significantly weaken the connectivity of the entire path. The number of intermediate basic thermal control units included in the effective compensation path. This is the weighting coefficient for the weakest link, with a value ranging from 0 to 1. The larger the value, the more it is influenced by the weakest link.

[0091] The above-mentioned weakest link is used as a composite measure of overall connectivity. It can simultaneously reflect both local failure and overall degradation risk modes along the patching path, avoiding a single... Or the limitations of a single product metric. In this embodiment, it is preferable to take... , , .

[0092] Step A403: Shell safety factor Thickness-rapid descent two-factor calculation.

[0093] Shell safety factor Used to characterize the basic thermal control unit Is the area suitable for strong cooling or heating regulation? Considering that an excessively thin shell layer may lead to surface cracking of the casting due to thermal stress concentration between the mold wall and the casting, and that excessively rapid temperature drop may cause surface defects or abnormal residual stress due to thermal shock, It is composed of a shell thickness factor and a wall velocity drop factor, which limit the intensity of regulation from the two dimensions of "geometric safety" and "dynamic safety".

[0094] Specifically, for boundary-type basic thermal control units (i.e., basic thermal control units directly in contact with the mold wall), the solid fraction must be statistically and continuously satisfied along the normal direction of the mold wall into the interior of the casting, with a solid fraction not less than [value missing]. The number of floors, denoted as The grid step size is Then the corresponding shell thickness satisfies: ; in, A solid fraction threshold for shell determination is defined, which reflects the minimum solid fraction level required for a "stable shell to be formed".

[0095] Meanwhile, the local velocity drop index of the wall is defined as follows: ; This metric measures the rate of change of the mold wall equivalent temperature over adjacent sampling periods. The larger the value, the more severe the local temperature drop (or rise) in the mold wall.

[0096] Furthermore, the shell safety factor satisfies: ; In the formula, To preset the shell safety thickness threshold, This is a preset safety threshold for local rapid descent of the mold wall. The first one... This reflects "geometric safety," meaning that further cooling commands are only allowed after the shell reaches a certain thickness—if the shell has not reached that thickness... At that time, the first The term approaches 0, thus significantly lowering... The second one This item reflects "kinetic safety," meaning the shell wall temperature drop rate should be below a safety threshold; otherwise, even if the shell thickness meets the standard, the cooling intensity should be limited. Approaching or exceeding At that time, the second The term approaching 0 also significantly lowers [the value / value]. After multiplying the two factors, only when the shell is both thickness-safe and descent-safe, Only then can a high level be maintained.

[0097] For non-boundary type basic thermal control units (i.e., internal basic thermal control units that do not directly contact the mold wall), since there is no shell concept that directly contacts the mold wall, it is directly taken as... No shell security restrictions are imposed on it.

[0098] In this embodiment, it is preferred to take , , .

[0099] Thus far, step A4 has simultaneously provided three major coupling quantitative indicators for each basic thermal control unit. , and The current state of the basic thermal control unit is fully characterized from three dimensions: "suppression required", "suppression allowed", and "suppression safe", which constitute the core criterion basis for the dynamic reconstruction of the control group in step A5.

[0100] Step A5: Based on the hot spot risk value, the shrinkage channel connectivity coefficient and the shell safety factor, the basic thermal control unit is dynamically reconstructed and grouped. Each basic thermal control unit is divided into a hot spot suppression group, a shrinkage channel protection group or a buffer stability group, and differentiated collaborative temperature control is implemented for the three types of control groups.

[0101] This step is the core of the entire dynamic control method, and its purpose is to calculate the three coupled quantitative indicators obtained in step A4. , and Within each control cycle, all basic thermal control units are dynamically reconfigured and grouped, dividing each unit into one of three groups: a hot spot suppression group, a feeding channel protection group, or a buffer stabilization group. This dynamic reconfiguration mechanism allows the boundaries of the control groups to be adjusted in real time as hot spots migrate, feeding channels evolve, and shells develop, fundamentally overcoming the shortcomings of fixed-zone adjustment methods in adapting to the dynamic characteristics of the casting process. Specifically, it includes the following sub-steps: Step A501: Hotspot center identification based on hotspot risk value.

[0102] The starting point for dynamic reconfiguration of the control group is the identification of hotspot centers. Within each control cycle, all basic thermal control units are first screened for hotspot risk values ​​not less than a preset hotspot risk threshold. The base thermal control unit with a locally maximum thermal risk value relative to its adjacent base thermal control unit is considered the hotspot center. That is, the base thermal control unit... A hotspot is identified if and only if the following condition is met: And for All adjacent basic thermal control units All .

[0103] The additional condition of "local maxima" is introduced to avoid identifying all units as hotspot centers within contiguous areas where the overall hot spot risk value is high. Without this condition, large areas would become hotspot centers during the later stages of solidification. and When the overall risk level is too high, the number of hotspot centers will increase dramatically, leading to an excessive number of hotspot suppression groups in subsequent step A503 and a dispersion of control resources. This results in a loss of targeted suppression capabilities for truly high-risk areas. The "local maximum" condition ensures that hotspot centers always correspond to the local peak value of hotspot risk values ​​within their neighborhood, thereby guaranteeing the sparsity and targeting of subsequent control group divisions.

[0104] Step A502: Hotspot center classification based on the channel connectivity coefficient and shell safety coefficient.

[0105] For each hotspot center identified in step A501 Relying solely on the thermal risk value is insufficient to determine whether to impose a strong cooling command—the connectivity coefficient of its compensation channels must also be examined simultaneously. and shell safety factor This is to determine whether suppression is permissible and whether suppression is safe. Therefore, this sub-step further divides hotspot centers into two categories: those that can be directly suppressed and those that are protected. The classification rules are as follows: when , and At that time, the basic thermal control unit Including hotspot centers in the set that can be directly suppressed indicates It is necessary to suppress ( (Meets standards) and the path remains connected. (Meets standards), and the shell is also in a safe state. (If it meets the standard), a strong cooling command can be applied to it without causing the complete failure of the feeding channel or abnormal thermal stress in the shell. when but or At that time, the basic thermal control unit Inclusion in the protected hotspot center set indicates Although suppression is required, the feeding path is nearing failure or the shell is in an unsafe state. If a strong cooling command is applied at this time, it will cause the feeding channel to fail completely or the shell to have abnormal thermal stress. Therefore, strong cooling is not applied, and instead, protective operations are performed on the feeding path or the shell.

[0106] In the formula, , , These are the hot spot risk threshold, the shrinkage channel connectivity threshold, and the shell safety threshold, respectively. In this embodiment, it is preferred to select... , , .

[0107] By using the two-level classification mechanism of this sub-step, the criteria for "whether the hot spot should be cooled" and "whether the hot spot can be cooled" are decoupled at the criterion level, thus avoiding the process contradictions caused by using only the hot spot risk value as the strong cooling trigger condition, such as "missing the shrinkage compensation in order to eliminate the hot spot" or "damaging the shell in order to eliminate the hot spot".

[0108] Step A503: Dynamic construction and periodic reconfiguration of the three types of control groups.

[0109] Based on the secondary classification results of step A502, three control groups were further constructed: For each hot spot center that can be directly suppressed, a corresponding hot spot suppression group is constructed. The hot spot suppression group takes the hot spot center that can be directly suppressed as the core and extends several adjacent basic thermal control units around it. The extension range can be adaptively adjusted according to the hot spot risk value of the hot spot center - the larger the hot spot risk value, the larger the extension range, so as to ensure that the core and edge of the high-risk area are effectively covered. For each hot spot center (including hot spots that can be directly suppressed and protective hot spots) to the effective feeding path to the feeding source area and its adjacent area, a corresponding feeding channel protection group is constructed. This control group covers the critical path that undertakes the feeding flow function and is the "feeding lifeline" that must be preserved when the hot spot suppression group applies the cooling command. The remaining basic thermal control units that were not classified into the hot spot suppression group and the feeding channel protection group are uniformly constructed into a buffer stabilization group. This control group is responsible for maintaining the stability of the overall temperature field and avoiding large-scale drift of the overall temperature field of the mold.

[0110] It should be noted that the hot spot suppression group, the shrinkage channel protection group, and the buffer stabilization group are not determined and fixed at the time of control startup, but are adjusted according to the latest calculations in each control cycle. , and Repeat steps A501 to A503. This dynamic reconfiguration mechanism allows the boundary of the control group to be adjusted in real time as hot spots migrate, the feeding channels evolve, and the shell develops: when a basic thermal control unit... As it solidifies, it rises and crosses... At that time, it can dynamically switch from the buffer stabilization group to the thermal block suppression group or the feed-in channel protection group; when a certain basic thermal control unit's It decreases to below as the solid fraction of its downstream units increases. When the thermal control unit is in a certain state, it can dynamically switch from the thermal suppression group to the feeding channel protection group; when the local solidification of a certain basic thermal control unit is completed, it can exit the thermal suppression group and be assigned to the buffer stabilization group. This dynamic switching process is the core mechanism that distinguishes this invention from the traditional "fixed zone adjustment" method, fundamentally ensuring the real-time matching between the control strategy and the dynamic characteristics of the casting process.

[0111] Step A6: Switch the solidification stage according to the global average solid fraction until all remaining liquid phase basic thermal control units fall into the preset feeding and capture zone.

[0112] The purpose of this step is to apply differentiated collaborative temperature control strategies to the three control groups obtained from the dynamic reconstruction in step A5, so that the control objectives and control methods of each control group cooperate to achieve the overall control objective of "eliminating hot spots, protecting feeding, maintaining the shell, and stabilizing the whole system". Simultaneously, stage switching is performed according to the overall solidification process of the casting, so that different solidification stages adopt corresponding control strategies and priority rankings, ultimately guiding the final solidification position of the remaining liquid phase region to the preset feeding capture zone. Specifically, it includes the following sub-steps: Step A601: Pulse cooling control and suppression permission factor gating of the thermal suppression group.

[0113] Basic thermal control unit in thermal suppression group Pulsed cooling control is implemented. Considering that although the connectivity coefficient of the compensation channel and the shell safety factor have both reached their corresponding thresholds in step A502, if their values ​​are only slightly higher than the thresholds, further applying a full-amplitude cooling command may still push them past the thresholds and into the unsafe zone. Therefore, a suppression allowance factor is introduced. Continuous gating of the cooling control quantity allows the intensity of the cooling command to vary. and The "safety margin" changes smoothly. Suppress the licensing factor. satisfy: ; As can be seen from the above formula, when or When the corresponding threshold is just crossed, Approaching zero, meaning the cooling command is strongly suppressed, reflects the process intention of "cautiously suppressing it when the target is just met," only when... and When all are significantly higher than the corresponding threshold, It's only close to 1, allowing for full-range cooling.

[0114] Under the gating of the suppression permission factor, the cooling control quantity of the thermal suppression group satisfies: ; In the formula, Basic thermal control unit The reference target temperature at the current solidification stage , , To control the gain, three types of driving terms are identified: "heat point risk deviation", "final condensation timing deviation", and "temperature deviation". Indicates when When 0 is taken, Take 1 in the first case, and take 1 in the other cases. itself.

[0115] Heating control quantity corresponding to the thermal suppression group The value is uniformly set to 0, meaning the thermal suppression group does not apply any heating commands.

[0116] Furthermore, the cooling circuit corresponding to the thermal suppression group is driven by a pulse duty cycle, and its duty cycle is equal to... The corresponding cooling pulse conduction duration is: ; In the formula, The pulse cycle is used. The advantage of pulsed cooling over continuous cooling is that it can maintain the average cooling intensity while allowing sufficient time for heat redistribution between the mold wall and the casting, avoiding localized temperature drop shocks and reducing the risk of abnormal thermal stress.

[0117] In this embodiment, it is preferred to take , , , .

[0118] Step A602: Micro-heating control and cooling limit of the compensation channel protection group.

[0119] Basic thermal control unit in the feed channel protection group In principle, strong cooling commands are prohibited, while micro-heating or heat preservation commands should be applied when necessary to maintain the connectivity of the feeding path, maintain the correct temperature gradient in the feeding direction, and suppress the development of isolation tendencies. Its heating control quantity satisfies: ; In the formula, This means that the expression within the parentheses is only included in the summation, reflecting the design intent of "compensating for heating only in unfavorable directions deviating from the reference value." , , To control the gain, To protect reference connectivity, it reflects the target connectivity level that the compensation channel protection group aims to maintain. The reference value for the temperature gradient along the target feeding direction reflects the minimum feeding direction gradient to be maintained. The isolation tendency reference value reflects the upper limit of the isolation tendency to be suppressed. The three deviations correspond to three types of operating conditions that require compensation through heating: "decreased connectivity of the compensation channel", "insufficient temperature gradient in the compensation direction" and "increased isolation tendency". The three are summed and then limited by the SAT function to obtain the final heating control value.

[0120] At the same time, the cooling control amount of the feed channel protection group Set upper limit : ; To avoid unexpected forced cooling of the feed path during process transitions, changes in control group boundaries, or in scenarios involving overlapping adjustments of multiple control groups. Even if the cooling command from an adjacent hot spot suppression group diffuses to this group through heat transfer within the mold wall, The presence of this also ensures that the cooling intensity of this group does not exceed the safe level.

[0121] In this embodiment, it is preferred to take , , , .

[0122] Step A603: Buffer band interval maintenance control of the buffer stabilization group.

[0123] For the basic thermal control unit in the buffer stabilization group To maintain the stability of the overall temperature field, no strong cooling or heating intervention is required. Therefore, a buffer zone maintenance control is adopted to avoid frequent switching of control commands and causing overall temperature field drift during small temperature fluctuations. Specifically, a preset upper limit for the buffer zone temperature is set. and the lower limit of the buffer zone temperature ,but: when At that time, apply a small amount of cooling. ,and ; when At that time, apply a small amount of heat. ,and ; when At that time, maintain the current control state unchanged. and Maintain the value from the previous control cycle; In the formula, To buffer the stable group control gain, and Significantly smaller than , The control gain of the equal-temperature suppression group and the shrinkage channel protection group is adjusted to ensure that the control intensity of the buffer stabilization group is moderate and does not conflict with the dominant control direction of the three types of control groups. In this embodiment, it is preferred to select... .

[0124] Step A604: Solidification stage switching based on global average solid fraction.

[0125] To ensure that different solidification stages employ appropriate control strategies and priority rankings, the global average solid fraction is defined as: ; In the formula, N represents the total number of basic thermal control units. This index reflects the overall solidification progress of the casting, providing a simple and physically meaningful criterion for stage switching.

[0126] according to Based on the given timeframe, the entire casting process is divided into three stages: mold filling and early shell prevention, solidification gradient establishment, and final solidification capture. The control strategies for each stage are rearranged as follows: when At this stage, the system is in the filling and early shell prevention phase. During this phase, most areas of the casting are still in a liquid phase or low solids state. The main process risks are premature shelling in thin-walled areas and feeding channel areas. Therefore, the primary goal of this phase is to prevent premature shelling. A low upper limit is set for the cooling control of all basic thermal control units, and the priority of the feeding channel protection group is placed above that of the hot spot suppression group. That is, when the same basic thermal control unit meets the judgment conditions of both the hot spot suppression group and the feeding channel protection group, it is treated according to the feeding channel protection group first, so as to avoid applying any form of cooling disturbance to the feeding channel in the early stage of solidification.

[0127] when At this stage, the system is in the solidification gradient establishment phase. During this phase, the casting solidification is in full swing, the hot spot region begins to show a tendency for late solidification, and the feeding channels also begin to exhibit varying degrees of localized solidification. Therefore, this phase focuses on suppressing areas with high hot spot risk values ​​while strictly protecting the feeding path to establish and maintain the target solidification gradient of "solidification at the far end first, followed by solidification at the feeding source end." This phase also increases the frequency of dynamic reconfiguration of the control group, for example, changing the reconfiguration from every control cycle to once every half control cycle, to cope with the drastic changes in hot spot migration and feeding channel evolution during this phase.

[0128] when At this stage, the system is in the final solidification capture stage. Most of the casting has solidified in this stage, leaving only a small amount of isolated or semi-isolated liquid phase. Therefore, the main objective of this stage is to guide the remaining liquid phase to the preset feeding capture zone. This preset feeding capture zone is located near the riser, ingate, or riser pipe, and is the target final solidification zone from which continuous molten metal replenishment from the feeding source can be obtained. When all remaining liquid phase is within the basic thermal control unit (i.e., meeting the requirements...), the system is in the final solidification capture stage. When all the basic thermal control units fall into the preset feeding and capture zone, the dynamic reconstruction control process ends and the heat preservation end program is entered. The heat preservation end program makes the entire casting complete the final solidification at the predetermined cooling rate, and then enters the mold opening and demolding process.

[0129] In the formula, and The first and second switching thresholds for the preset solidification stage are, and In this embodiment, it is preferred to take... , .

[0130] This invention divides the mold and its adjacent casting area into basic thermal control units, and binds temperature measurement points, execution loops, and feeding paths to each basic thermal control unit, establishing a ternary binding relationship of "temperature measurement-execution-feeding". Based on this, a coupled prediction model of the temperature fields on both sides of the mold wall and the casting is constructed and corrected online using measured temperatures. This model can simultaneously reflect the thermal diffusion process on the mold side and the phase transformation solidification process on the casting side. Furthermore, through three coupled quantitative indicators—thermal block risk value, feeding channel connectivity coefficient, and shell safety factor—each element is evaluated from three complementary dimensions: "whether suppression is needed", "whether suppression is permissible", and "whether suppression is safe". The current state of the basic thermal control unit is comprehensively evaluated, and the hot spot identification is expanded from a single temperature criterion to a composite criterion. Furthermore, through the dynamic reconstruction mechanism of the control group based on the above three quantitative indicators and the differentiated collaborative temperature control strategy, combined with the solidification stage switching mechanism based on the global average solid fraction, the control strategy is dynamically matched with the solidification process. Finally, the final solidification position of the remaining liquid phase region is stably guided to the preset feeding and capture zone. This solves the problem that the traditional method, which mainly relies on preset temperature control parameters and fixed partition adjustment, is difficult to dynamically control the mold temperature field according to the real-time solidification state during the casting process, and is difficult to take into account both hot spot suppression and feeding channel protection.

[0131] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for dynamic control of the mold temperature field during casting, characterized in that, Includes the following steps: Step A1: Construct a control system consisting of a temperature measurement unit, a calculation control unit, and an execution unit. Divide the mold and its adjacent casting area into several basic thermal control units. Each basic thermal control unit is bound to at least one temperature measurement point and at least one execution loop. Establish a feeding path from each basic thermal control unit to the feeding source area. Step A2: Establish a heat dissipation equilibrium prediction model for the equivalent temperature of the mold wall and an apparent heat capacity method prediction model for the equivalent temperature of adjacent castings, and perform online correction of the prediction results based on the measured temperature. Step A3: Based on the corrected equivalent temperature of adjacent castings, calculate the solid fraction and expected final solidification time of each basic thermal control unit, establish the target solidification path according to the path length from each basic thermal control unit to the feeding source area, and obtain the final solidification time deviation. Step A4: Based on the state variables obtained in Steps A2 and A3, calculate the thermal node risk value, the compensating channel connectivity coefficient, and the shell safety factor for each basic thermal control unit. Step A5: Based on the hot spot risk value, the shrinkage channel connectivity coefficient and the shell safety factor, the basic thermal control unit is dynamically reconstructed and grouped, and each basic thermal control unit is divided into the hot spot suppression group, the shrinkage channel protection group or the buffer stability group, and differentiated collaborative temperature control is implemented for the three types of control groups. Step A6: Switch the solidification stage according to the global average solid fraction until all remaining liquid phase basic thermal control units fall into the preset feeding and capture zone.

2. The method for dynamic control of the mold temperature field during casting according to claim 1, characterized in that, In step A1, the area adjacent to the riser, ingate, or riser pipe is defined as the feeding source area; For any basic thermal control unit, if there are multiple feasible compensation paths to the compensation source region, the compensation channel connectivity coefficient corresponding to each feasible compensation path is calculated in each control cycle, and the feasible compensation path with the largest current compensation channel connectivity coefficient is selected as the effective compensation path of the basic thermal control unit in that control cycle.

3. The method for dynamic control of the mold temperature field during casting according to claim 1, characterized in that, In step A2, the heat dissipation balance prediction model for the equivalent temperature of the mold wall is constructed based on four types of heat exchange processes: heat transfer inside the mold wall between adjacent basic thermal control units, interfacial heat transfer between the mold wall and the casting, heating circuit input, and cooling circuit output. The heating input is the product of the heating control quantity and the maximum output capacity of the heating circuit, and the cooling output is the product of the cooling control quantity and the maximum output capacity of the cooling circuit. Both the heating control quantity and the cooling control quantity take values ​​between 0 and 1. The apparent heat capacity method prediction model for the equivalent temperature of adjacent castings incorporates the latent heat of solidification into the effective heat capacity, so that the adjacent area of ​​the casting takes the liquid phase specific heat capacity in the liquid phase region, the superposition value of the ratio of the sensible heat specific heat capacity of the solid-liquid two-phase region to the latent heat of solidification and the liquid-solid phase temperature difference in the solid phase region, and the solid phase specific heat capacity in the solid phase region. Furthermore, the heat dissipation balance prediction model of the equivalent temperature of the mold wall and the apparent heat capacity prediction model of the equivalent temperature of the adjacent casting are coupled and iterated through the interface heat transfer term between the mold wall and the casting.

4. The method for dynamic control of the mold temperature field during casting according to claim 3, characterized in that, In step A2, for the i-th basic thermal control unit, a set of temperature measurement points corresponding to it is established. The weight of each temperature measurement point to the basic thermal control unit is assigned according to the reciprocal distance weighting method. The measured temperature of all normal temperature measurement points in the set is weighted and averaged using the weight. The weighted average result is then fused with the mold wall predicted temperature according to the correction coefficient to obtain the mold wall corrected temperature. The equivalent temperature of the adjacent casting adopts the mold wall-casting linkage correction method, that is, the product of the mold wall correction amount and the transfer correction coefficient is superimposed on the predicted value of the equivalent temperature of the adjacent casting. The mold wall correction amount is the difference between the mold wall correction temperature and the mold wall prediction temperature. For any temperature measurement point, if the temperature jump exceeds the preset jump threshold for two consecutive sampling cycles, or the temperature deviation from other temperature measurement points under the same basic thermal control unit exceeds the preset deviation threshold, then the temperature measurement point is determined to be an abnormal temperature measurement point and is blocked from the corresponding temperature measurement point set in the current control cycle.

5. The method for dynamic control of the mold temperature field during casting according to claim 1, characterized in that, In step A3, a target solidification path is established based on the path length from each basic thermal control unit to the feeding source area. The target final solidification time of each basic thermal control unit in the target solidification path satisfies the condition that the basic thermal control unit with a longer path from the feeding source area completes solidification earlier, and the basic thermal control unit with a shorter path from the feeding source area completes solidification later, so that the casting solidifies in the order of the far end solidifying first and the feeding source end solidifying later. The estimated final solidification time of the i-th basic thermal control unit is estimated based on the difference between the equivalent temperature and solidus temperature of its current adjacent casting and the absolute value of the current cooling rate. When the cooling rate is zero, positive, or too small, a preset minimum positive number is used as the lower limit of the cooling rate to avoid the occurrence of singular values ​​in the estimated final solidification time. The final setting time deviation of the i-th basic thermal control unit is the difference between the expected final setting time and the target final setting time of the basic thermal control unit. When the final setting time deviation is greater than zero, it indicates that the basic thermal control unit has a late setting trend relative to the target solidification path and has the potential to form an isolated hot spot.

6. The method for dynamic control of the mold temperature field during casting according to claim 1, characterized in that, In step A4, the first Thermal risk value of each basic thermal control unit From superheat component Final condensation weight Temperature gradient component in the feeding direction and the tendency to isolate Jointly determined: ； In the formula, ; The superheat component reflects the degree of superheating of the current equivalent temperature of the adjacent casting relative to the preset superheat reference temperature of the basic thermal control unit. The final solidification lag component reflects the degree of delayed solidification of the basic thermal control unit relative to the target solidification path; The temperature gradient component in the feeding direction reflects the degree to which the equivalent temperature of the adjacent casting of the next basic thermal control unit, which is one step ahead of the basic thermal control unit along its effective feeding path, is higher than the equivalent temperature of the adjacent casting of the basic thermal control unit. The isolation tendency component is the arithmetic mean of the solid fractions of all first-order adjacent basic thermal control units of the basic thermal control unit. Furthermore, the superheat component, the final stagnation component, and the temperature gradient component in the feeding direction are all normalized by preset reference values ​​and truncated between 0 and 1.

7. The method for dynamic control of the mold temperature field during casting according to claim 1, characterized in that, In step A4, the first The connectivity coefficient of the compensation channel of each basic thermal control unit A composite metric combining the weakest link and overall connectivity is used: ； in, For the intermediate basic thermal control unit on the effective feeding path of the basic thermal control unit Local connectivity This represents the minimum local connectivity among all paths on the effective path reduction path. This represents the product of the local connectivity of each element on the effective simplification path. Geometric mean The number of intermediate basic thermal control units included in the effective compensation path. This represents the weighting coefficient for the weakest link.

8. The method for dynamic control of the mold temperature field during casting according to claim 1, characterized in that, In step A4, the first Shell safety factor of each basic thermal control unit It is composed of a shell thickness factor and a mold wall rate drop factor; The shell thickness factor is obtained by truncating the ratio of the shell thickness formed by the product of the number of layers at the basic thermal control unit that continuously satisfy the solidity not less than the preset shell determination solidity threshold and the grid step size, to the preset shell safety thickness threshold. The wall velocity drop factor is obtained by truncating the ratio of the absolute value of the rate of change of the equivalent temperature of the wall in the basic thermal control unit within adjacent sampling periods to a preset local velocity drop safety threshold for the wall. Furthermore, for non-boundary type basic thermal control units, .

9. A method for dynamic control of the mold temperature field during casting according to any one of claims 6 to 8, characterized in that, In step A5, all basic thermal control units are first screened for thermal node risk values ​​that are not less than a preset thermal node risk threshold. Furthermore, the basic thermal control unit with a local maximum thermal risk value relative to its adjacent basic thermal control unit is designated as the hotspot center, and the hotspot centers are then classified and control groups are constructed according to the following rules: when , and At that time, the corresponding basic thermal control unit is assigned to the set of hot spot centers that can be directly suppressed; when but or At that time, the corresponding basic thermal control unit is assigned to the protective hotspot center set. and These are the preset compensation channel connectivity threshold and the preset shell security threshold, respectively. For each directly suppressable hot spot center, a hot spot suppression group is constructed; for each hot spot center to the effective shrinkage path from the shrinkage source area and its adjacent area, a shrinkage channel protection group is constructed; and the remaining basic thermal control units are used to construct a buffer stabilization group. For the basic thermal control unit in the thermal suppression group, a suppression permission factor is introduced. Gating the cooling control quantity: ； In the formula, Time to take ,when Time to take In other cases, take In itself, when or When the corresponding threshold is just crossed, Approaching zero, only when and When all are significantly higher than the corresponding threshold, Close to 1; For the basic thermal control unit in the buffer stabilization group, the upper and lower limits of the buffer zone temperature are preset. When the mold wall temperature is higher than the upper limit, a small amount of cooling is applied, and when it is lower than the lower limit, a small amount of heating is applied. When it is within the buffer zone, the current control state is maintained.

10. The method for dynamic control of the mold temperature field during casting according to claim 1, characterized in that, In step A6, the global average solid fraction is defined as the arithmetic mean of the solid fractions of all basic thermal control units; When the global average solid fraction is less than the preset first switching threshold During the filling and early shell prevention stage, the cooling control quantity of all basic thermal control units is set to a lower upper limit. When the same basic thermal control unit meets the judgment conditions of both the thermal block suppression group and the shrinkage channel protection group, it is processed according to the shrinkage channel protection group first. When the global average solid fraction is not less than the preset first switching threshold And less than the preset second switching threshold At this time, during the solidification gradient establishment stage, the focus is on suppressing areas with high thermal risk values ​​and maintaining the temperature gradient in the feeding direction to increase the dynamic reconfiguration frequency of the control group. When the global average solid fraction is not less than the preset second switching threshold At this time, during the final solidification capture stage, the remaining liquid phase region is guided to the preset feeding capture zone, which is located near the riser, ingate or riser pipe; When all remaining liquid phase thermal control units fall into the preset feeding and capture zone, the dynamic reconfiguration control process ends and the insulation termination procedure begins. and This is the preset threshold for switching between solidification stages.

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