CN-121995886-A - Intelligent regulation and control system for large-scale production molding of cubic zirconia material

CN121995886ACN 121995886 ACN121995886 ACN 121995886ACN-121995886-A

Abstract

The invention relates to the technical field of artificial crystal growth, and discloses a large-scale production molding intelligent regulation and control system of a cubic zirconia material, which comprises a central cooperative control module, a partition cooling data monitoring module, a thermal contact resistance liquid level analysis module, a vertical temperature gradient construction module and an inductive energy dynamic matching module, wherein the partition cooling data monitoring module, the thermal contact resistance liquid level analysis module, the vertical temperature gradient construction module and the inductive energy dynamic matching module are connected through a bus, the thermal contact resistance liquid level analysis module inverts the real-time liquid level of a melt based on the heat loss power of a side wall, the vertical temperature gradient construction module constructs a vertical heat flow channel by adjusting the difference of the flow velocity of cooling water at the side wall and the bottom, the inductive energy dynamic matching module dynamically adjusts the radio frequency output power according to the liquid level height, and the central cooperative control module comprehensively coordinates the whole flow of raw material melting, crystal growth and annealing shutdown according to thermodynamic characteristics. The invention solves the technical problems of difficult monitoring of the liquid level of the high-temperature melt and difficult control of the thermal field, realizes the automatic closed-loop control of the crystal growth, and remarkably improves the structural uniformity and the yield of large-size single crystals.

Inventors

LIN JIANXIN
XU RONGTAO
XU RONGGUI

Assignees

汶川县新璞新材料科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260210

Claims (10)

1. The intelligent control system for large-scale production molding of the cubic zirconia material is characterized by comprising the following components: the partition cooling data monitoring module is respectively connected with sensor ports of the side wall cooling loop and the bottom cooling loop of the cold crucible, and is used for independently collecting fluid thermal parameters of the side wall waterway and the bottom waterway and outputting side wall heat loss power and bottom heat loss power calculated based on a thermodynamic energy conservation principle; the thermal contact resistance liquid level analysis module is connected with the partition cooling data monitoring module and is used for receiving the side wall heat loss power data and inverting the real-time height of the melt liquid level relative to the bottom of the crucible based on the physical difference of the heat conduction efficiency of the liquid zirconia and the solid zirconia to the inner wall of the cold crucible; the vertical temperature gradient construction module is connected with a flow regulation executing mechanism of the cold crucible cooling waterway and is used for executing a hydrodynamic regulation strategy, and a vertical heat flow channel is constructed by controlling the sensible heat exchange trend limit of side wall cooling water and the maintenance of high turbulence flow velocity of bottom cooling water; The inductive energy dynamic matching module is respectively connected with the contact thermal resistance liquid level analysis module and a control loop of the radio frequency power supply, and is used for mapping the volume of the residual liquid phase melt according to the real-time height and dynamically adjusting the output parameters of the radio frequency power supply according to a linear attenuation algorithm; The central cooperative control module is respectively connected with the partition cooling data monitoring module, the contact thermal resistance liquid level analysis module, the vertical temperature gradient construction module and the inductive energy dynamic matching module and is used for overall production cycle control, and each module is coordinated to execute a phased control strategy according to thermodynamic characteristics of different stages of crystal growth.
2. The intelligent regulation and control system for large-scale production molding of the cubic zirconia material according to claim 1, wherein the partition cooling data monitoring module comprises a side wall cooling loop and a bottom cooling loop which are physically isolated, wherein a temperature sensor and a flow transmitter are respectively arranged at an inlet and an outlet of the side wall cooling loop and the bottom cooling loop; The partition cooling data monitoring module calculates the side wall heat loss power and the bottom heat loss power in real time respectively by calculating the product of the specific heat capacity of water, the mass flow after the density correction and the temperature difference value between the water outlet and the water inlet, and synchronously acquires the total input energy standard of the radio frequency power supply.
3. The intelligent regulation and control system for large-scale production molding of cubic zirconia material according to claim 1, wherein the specific way for calculating the real-time height of the melt liquid level by the thermal contact resistance liquid level analysis module is as follows: Establishing a full-load liquid-phase thermal power reference and an all-solid-state background thermal power reference, wherein the full-load liquid-phase thermal power reference is the stable thermal power of the side wall waterway when the raw materials are completely melted and the liquid level reaches the maximum value, and the all-solid-state background thermal power reference is the stable thermal power of the side wall waterway when the materials are completely solidified; And calculating the liquid level height by using a normalized power attenuation model based on the side wall heat loss power acquired in real time, wherein the liquid level height is in direct proportion to the difference value of the real-time side wall heat loss power minus the all-solid background heat power reference, is in inverse proportion to the difference value of the full-load liquid phase heat power reference minus the all-solid background heat power reference, and is combined with the crucible shape correction coefficient to obtain the final real-time melt liquid level height.
4. The intelligent regulation and control system for mass production of cubic zirconia material according to claim 1, wherein the vertical temperature gradient construction module performs a differential cooling strategy during the crystal growth phase: controlling the bottom waterway to maintain high turbulence flow speed, so that the bottom copper wall maintains a low-temperature state close to the water inlet temperature, and forming a low-interface thermal resistance heat dissipation channel; Simultaneously, performing closed-loop control based on the real-time temperature difference of the side wall waterway, reducing the valve opening of the side wall waterway to reduce the flow, lifting the outlet water temperature of the side wall to a target set value close to the boiling state, and forming a high thermal resistance boundary layer on the inner wall of the side wall copper pipe by utilizing a high-temperature water film; and redirecting the heat flow vector in the melt to be directed to the vertical direction of the bottom of the low-temperature crucible from the center of the high-temperature melt through the difference of the heat resistance of the side wall and the bottom.
5. The intelligent regulation and control system for large-scale production molding of cubic zirconia material according to claim 1, wherein the inductive energy dynamic matching module is configured with a constant power density control model; the model calculates the volume of the residual liquid phase melt based on the real-time melt liquid level height and the inner diameter and the sectional area of the crucible; The inductive energy dynamic matching module calculates target output power of the radio frequency power supply according to a linear attenuation algorithm, so that the target output power is equal to the sum of basic loss power and power required by a liquid phase part, wherein the power required by the liquid phase part is the product of an optimal unit volume melt power density constant, an effective cross-sectional area in a cold crucible and a real-time melt liquid level.
6. The intelligent regulation and control system for large-scale production molding of cubic zirconia material according to claim 1, wherein the inductive energy dynamic matching module is further integrated with a frequency automatic tracking subroutine; the frequency automatic tracking subroutine is configured to monitor the phase difference of the oscillation circuit in real time during the crystal growth process, and automatically adjust the driving frequency of the oscillation circuit when the phase lock loss or the increase of the reflected power is monitored, so as to compensate the load impedance drift caused by the decrease of the conductive liquid phase and the increase of the insulating solid phase in the crucible.
7. The intelligent regulation and control system for mass production of cubic zirconia material according to claim 1, wherein the central cooperative control module is configured with a heat balance determination logic; and when the absolute value of the change rate is smaller than a preset stable threshold value in a plurality of continuous sampling periods, judging that the raw material is completely melted and the melt flow field reaches a stable state, and triggering the contact thermal resistance liquid level analysis module to execute a reference sampling program to lock full-load thermal power.
8. The intelligent regulation and control system for large-scale production molding of cubic zirconia material according to claim 1, wherein the central cooperative control module is configured to execute parallel control flow in a crystal growth stage to realize dynamic matching of a solid-liquid interface advancing speed and a mechanical movement speed, and is specifically configured to calculate a liquid level descending speed derived from a liquid level height change rate and calculate deviation between the liquid level descending speed and a servo mechanism mechanical descending speed; When the liquid level falling speed is smaller than the mechanical falling speed, the vertical temperature gradient building module is configured to send a command to reduce the mechanical falling speed or finely adjust and increase the cooling strength of the vertical temperature gradient building module; When the liquid level falling speed is greater than the mechanical falling speed, the liquid level falling speed is configured to send a command to increase the mechanical falling speed.
9. The intelligent regulation and control system for large-scale production molding of cubic zirconia material according to claim 4, wherein the vertical temperature gradient construction module is further configured with vaporization safety threshold monitoring logic; And during the implementation of the high-temperature throttling control of the side wall, continuously monitoring the pressure drop and the temperature fluctuation of the side wall water flow, and once the fact that the outlet water temperature exceeds a preset safety alarm value or the flow rate fluctuates due to the gas-liquid two-phase flow characteristics is monitored, immediately and forcedly increasing the opening of the side wall waterway valve.
10. The intelligent regulation and control system for large-scale production molding of cubic zirconia material according to claim 1, wherein the central cooperative control module executes an exponential power attenuation strategy in an annealing stage after the end of crystal growth; The power attenuation strategy is to control the output power of the radio frequency power supply to attenuate exponentially with time, wherein the attenuation rate is determined by an annealing time constant, and the annealing time constant is related to the thermal expansion coefficient and the heat conduction coefficient of the crystal so as to control the cooling rate not to exceed the critical thermal shock threshold of the crystal.

Description

Intelligent regulation and control system for large-scale production molding of cubic zirconia material Technical Field The invention relates to the technical field of artificial crystal growth, in particular to an intelligent regulation and control system for large-scale production molding of a cubic zirconia material. Background The cubic zirconia has high hardness, high refractive index and excellent chemical stability, and is widely applied to the fields of artificial precious stones, laser window materials, high-temperature refractory materials and the like. Since pure zirconia is in monoclinic phase at normal temperature, yttrium oxide or calcium oxide and the like are usually added as a stabilizer in the production process to obtain cubic phase stable at room temperature. Given the high melting point of this material, up to 2750 ℃, conventional refractory materials or precious metal crucibles cannot withstand this high Wen Juyi introduction of impurities, cold crucible skeletal smelting (CCSM) is the dominant process for preparing such refractory oxide crystals. The process utilizes high-frequency electromagnetic induction coupling to heat raw materials in the cold crucible, and cooperates with the copper crucible wall with water cooling to forcedly dissipate heat, so that the materials close to the inner wall of the crucible form a layer of solid sintered shell to serve as a self-supporting container, and high-temperature smelting and crystallization are realized in an environment without refractory material pollution. In existing cold crucible melting processes, monitoring of the melt state and construction of the thermal field present technical challenges. Because the smelting environment has the characteristics of high temperature, strong electromagnetic radiation and high brightness, the contact sensor is difficult to stably work for a long time, and the non-contact measurement is often influenced by the shielding of volatile matters and surface crusting in the furnace, so that accurate real-time liquid level data is difficult to obtain, and the production process is more dependent on manual experience judgment. At the same time, conventional cooling systems employ uniform cooling parameters for the crucible sidewall and bottom, such that the melt heat tends to conduct radially toward the sidewall. Such radially-based temperature gradients tend to guide crystal growth in the horizontal direction, making it difficult to form vertical axial heat flow channels suitable for large-size single crystal growth, limiting the effective crystal volume of the single crystal. On the other hand, crystal growth is a process in which the load characteristics dynamically evolve. As the crystallization interface advances from bottom to top, the ratio of the conductive liquid phase to the insulating solid phase in the crucible continuously changes, resulting in drift of the equivalent load impedance of the induction coil. If a constant power output or discontinuous regulation mode is adopted, the dynamic requirement of the liquid phase volume change on the power density is difficult to adapt. In addition, mechanical traction mechanisms typically operate at a preset speed, making it difficult to respond in real time to the actual crystallization rate affected by the fluctuation of the thermal field. If the energy supply parameter and the mechanical motion parameter lack of real-time closed-loop linkage, the solid-liquid interface propulsion speed and the traction speed may deviate, and the growth quality and the batch stability of crystals are further affected. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an intelligent regulation and control system for large-scale production molding of a cubic zirconia material, which solves the problems that the liquid level of a high-temperature melt cannot be monitored in real time, a vertical heat flow channel is difficult to construct and the matching degree of radio frequency induction energy and crystal growth rate is low in the traditional cold crucible smelting process. The intelligent regulation and control system for the large-scale production molding of the cubic zirconia material comprises a central cooperative control module, a partition cooling data monitoring module, a contact thermal resistance liquid level analysis module, a vertical temperature gradient construction module and an inductive energy dynamic matching module. The central cooperative control module is respectively connected with the partition cooling data monitoring module, the contact thermal resistance liquid level analysis module, the vertical temperature gradient construction module and the inductive energy dynamic matching module in a communication way through an industrial field bus and is used for overall full life cycle control, and the modules are coordinated to execute a staged control strategy of raw material melting, crystal growth and annealing sh