Box-type furnace intelligent heat treatment production line management system

Abstract

The invention provides a box-type furnace intelligent heat treatment production line management system, and relates to the field of management systems, and the system comprises a data collection module which is used for obtaining the real-time process data of each heat treatment device of a box-type furnace intelligent heat treatment production line and workpiece parameters in the heat treatment devices; the parameter acquisition module is used for acquiring heat treatment procedure related material parameters of the workpiece, and the heat treatment procedure related material parameters comprise temperature section workpiece material parameters; the correlation analysis module is used for performing correlation analysis on the process data of the heat treatment equipment, the workpiece parameters in the heat treatment equipment and the heat treatment procedure related material parameters of the workpiece and outputting a correlation analysis result; and the PLC module selectively triggers the alarm module to give an alarm and regulates and controls the working state of the heat treatment equipment according to the correlation analysis result. According to the method, process deviation caused by splitting of real-time process data (such as actual heating temperature) of equipment and workpiece parameter data is avoided.

Description

Technical Field

[0001] This invention relates to the field of management systems, specifically to an intelligent heat treatment production line management system for box furnaces. Background Technology

[0002] Box furnaces are heat treatment furnaces with a box-shaped furnace chamber, mainly used for key heat treatment processes such as normalizing, quenching, tempering, annealing, carburizing, and nitriding of workpieces. Their core working principle involves converting electrical energy into heat energy through heating elements (such as resistance wires, silicon molybdenum rods, and infrared heating tubes) within the furnace chamber. Combined with the furnace's insulation structure, this maintains the target temperature environment, allowing the workpiece to achieve optimized microstructure under specific temperature and other conditions, thereby improving core performance indicators such as hardness, strength, toughness, and wear resistance.

[0003] Existing heat treatment furnace management systems, such as CN119105349A, a method for a centralized control management system for heat treatment of thick steel plates, have the following problems:

[0004] The relevant parameters of the heat treatment furnace (such as furnace temperature) and the workpiece temperature are measured separately. However, the correlation analysis between the relevant parameters of the heat treatment furnace (such as furnace temperature) and the workpiece temperature is not performed, which makes it impossible to assess the compatibility between the relevant parameters of the heat treatment furnace (such as furnace temperature) and the workpiece temperature, and may easily affect the heat treatment effect of the workpiece. Summary of the Invention

[0005] This invention provides an intelligent heat treatment production line management system for box furnaces to solve the technical problems mentioned in the background.

[0006] To address the aforementioned technical problems, this invention discloses an intelligent heat treatment production line management system for box furnaces, comprising:

[0007] Data acquisition module: used to acquire real-time process data and workpiece parameters of each heat treatment equipment in the intelligent heat treatment production line of box furnace;

[0008] Parameter acquisition module: used to acquire material parameters related to the heat treatment process of the workpiece. The material parameters related to the heat treatment process include workpiece material parameters for different temperature ranges.

[0009] The correlation analysis module is used to perform correlation analysis on the process data of the heat treatment equipment, the parameters of the workpiece in the heat treatment equipment, and the material parameters related to the heat treatment process of the workpiece, and output the correlation analysis results.

[0010] PLC module: Selectively triggers alarms from the alarm module and regulates the working status of the heat treatment equipment based on the correlation analysis results.

[0011] Preferably, the process data of the heat treatment equipment includes: the actual heating temperature of the area where the workpiece is heat treated within the heat treatment equipment; and the workpiece parameters include the workpiece temperature.

[0012] Preferably, the material parameters related to the heat treatment process of the workpiece include: the heat treatment time-standard workpiece temperature fitting curve corresponding to the heat treatment process of the workpiece and the temperature range-thermal expansion coefficient-thermal conductivity mapping table corresponding to the process of the workpiece.

[0013] The heat treatment time-standard workpiece temperature fitting curve is divided into multiple temperature segments, each temperature segment is continuous, and the ratio of the maximum slope value to the minimum slope value of each temperature segment satisfies the corresponding ratio range.

[0014] The correlation analysis module includes:

[0015] Calculation Unit 1: Used to calculate the rate of change of workpiece temperature based on workpiece temperature;

[0016] Analysis Unit 1: Determine the equivalent thermal stress change based on the coefficient of thermal expansion, the rate of temperature change, and the modulus of elasticity of the workpiece within the current temperature range.

[0017] Analysis Unit 2: Determine the equivalent heat flux parameters based on the actual heating temperature change rate of the heat treatment area of ​​the workpiece within the heat treatment equipment, the specific heat capacity of the workpiece, and the heated surface area of ​​the workpiece;

[0018] Analysis Unit 3: Used to determine the heat flow-thermal stress interaction factor based on the equivalent thermal stress change, equivalent heat flow parameters, and thermal conductivity corresponding to the current workpiece temperature range.

[0019] Preferably, the alarm module includes:

[0020] Alarm Unit 1: Used to issue an alarm when the rate of change of workpiece temperature is outside the preset range of the average rate of change of workpiece temperature in the corresponding temperature segment.

[0021] Alarm Unit 2: Used to trigger an alarm when the heat flow-thermal stress interaction factor is outside the corresponding normal range.

[0022] Preferably, the PLC module obtains the working status data and process data of each heat treatment equipment in the intelligent heat treatment production line of the box furnace through the communication network and the heat treatment equipment self-diagnosis.

[0023] The data acquisition module obtains real-time operating status data and process data of each heat treatment equipment in the box furnace intelligent heat treatment production line from the PLC module, as well as obtains workpiece parameters in the heat treatment equipment, and integrates them to form real-time production line data.

[0024] Preferred options also include:

[0025] Process Management Module: Used to set the process and parameters for workpieces that need to be processed by the intelligent heat treatment production line of box furnace;

[0026] Preferably, it also includes an equipment analysis module, which includes:

[0027] Thermal inertia analysis unit:

[0028] This is used to determine the time it takes for the working power to reach the temperature stabilization point and the actual heating temperature of the heat treatment area of ​​the workpiece when the temperature stabilizes, based on the actual heating temperature change of the heat treatment area of ​​the workpiece within the heat treatment equipment during the operation of the heat treatment equipment.

[0029] The thermal inertia characteristic coefficient and thermal inertia state coefficient of the heat treatment equipment are determined based on the time from the application of working power to temperature stabilization and the actual heating temperature of the workpiece heat treatment zone when the temperature stabilizes.

[0030] Sequence construction unit: used to construct a sequence of thermal inertia characteristic coefficients of the heat treatment equipment in chronological order based on the thermal inertia characteristic coefficients of the heat treatment equipment within the latest setting time period;

[0031] Thermal inertia variation analysis unit: used to determine the thermal inertia variation coefficient based on the thermal inertia characteristic coefficient sequence;

[0032] Curve construction unit: used to construct a working power-thermal inertia characteristic coefficient relationship model based on the thermal inertia characteristic coefficient of the heat treatment equipment within the latest set time period;

[0033] Thermal inertia gradient analysis unit: used to analyze the working power-thermal inertia characteristic coefficient relationship model to determine the thermal inertia gradient coefficient;

[0034] Early warning unit 1: Used to issue an early warning when any of the thermal inertia state coefficient, thermal inertia variation coefficient, or thermal inertia gradient coefficient is outside the corresponding normal range.

[0035] Preferably, the equipment analysis module also includes:

[0036] Decision unit: Used to determine the maximum allowable power for the next power adjustment based on the thermal inertia state coefficient when none of the warning units issue a warning.

[0037] Preferably, the process data for heat treatment equipment with an internal working atmosphere also includes: gas parameters inside the furnace cavity of the heat treatment equipment, including: gas flow rate, gas pressure, air temperature, and concentration of the working atmosphere.

[0038] Preferably, it also includes a furnace cavity analysis module, which includes:

[0039] Gas pressure-velocity correlation analysis unit: used to determine velocity characteristic factors based on gas velocity and gas pressure inside the furnace cavity of heat treatment equipment;

[0040] Atmosphere Concentration Sequence Construction Unit: Used to obtain the latest atmospheric concentration within the attention period and construct the atmospheric concentration sequence of the heat treatment equipment in chronological order of timestamps.

[0041] Atmosphere Concentration Analysis Unit: Used to determine the rate of change of atmosphere concentration based on the atmospheric concentration sequence of the heat treatment equipment.

[0042] Stage and Deviation Analysis Unit: Used to determine the heat treatment stage of the workpiece based on the workpiece temperature in the heat treatment equipment, and to determine the atmosphere concentration deviation coefficient by combining the workpiece heat treatment stage and the rate of change of atmosphere concentration.

[0043] Temperature-pressure correlation analysis unit: used to determine the temperature-pressure composite flow correction coefficient based on the air temperature and pressure inside the furnace cavity of the heat treatment equipment;

[0044] Early warning unit 2: Used to issue an early warning when the flow rate characteristic factor and the atmosphere concentration deviation coefficient are not within the corresponding normal range;

[0045] Flow rate determination unit: used to determine the target flow rate based on the flow velocity characteristic factor, atmosphere concentration deviation coefficient, and temperature-pressure composite flow rate correction coefficient;

[0046] The control module of the heat treatment equipment controls the actual working atmosphere flow rate of the heat treatment equipment to the target flow rate.

[0047] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The data acquisition module simultaneously acquires real-time process data from the equipment (such as actual heating temperature) and workpiece parameters (such as workpiece temperature). Combined with material parameters related to the heat treatment process of the workpiece obtained by the parameter acquisition module, the correlation analysis module achieves full-dimensional data linkage between "equipment-workpiece-material". This linkage can accurately capture the dynamic laws of heat transfer and microstructure transformation during heat treatment, avoiding process deviations caused by the disconnect between real-time process data from the equipment (such as actual heating temperature) and workpiece parameter data, and significantly improving the consistency of the workpiece's performance (such as hardness, strength, and toughness) after heat treatment.

[0050] By acquiring workpiece material parameters for different temperature ranges, the system can dynamically adjust process strategies based on material properties (such as thermal conductivity) for different materials and temperature ranges, resulting in more precise heat treatment.

[0051] When the correlation analysis result is abnormal, the control alarm module will sound an alarm and mark the corresponding heat treatment equipment as abnormal (which can be controlled to suspend operation); when the correlation analysis result is normal, the corresponding heat treatment equipment will be marked as normal.

[0052] This invention solves the problem raised in the background technology that "the relevant parameters of the heat treatment furnace (such as furnace temperature) and the workpiece temperature are not correlated and analyzed, making it impossible to assess the compatibility between the relevant parameters of the heat treatment furnace (such as furnace temperature) and the workpiece temperature, which can easily affect the heat treatment effect of the workpiece". Attached Figure Description

[0053] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0054] Figure 1 This is a schematic diagram of the components of the present invention. Detailed Implementation

[0055] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0056] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0057] The present invention provides the following embodiments:

[0058] Example 1: This embodiment of the invention provides an intelligent heat treatment production line management system for box furnaces, such as... Figure 1 As shown, it includes:

[0059] Data acquisition module: used to acquire real-time process data and workpiece parameters in each heat treatment equipment of the intelligent heat treatment production line of box furnace (can be acquired in real time or periodically).

[0060] Parameter acquisition module: used to acquire material parameters related to the heat treatment process of the workpiece. The material parameters related to the heat treatment process include workpiece material parameters for different temperature ranges.

[0061] The correlation analysis module is used to perform correlation analysis on the process data of the heat treatment equipment, the parameters of the workpiece in the heat treatment equipment, and the material parameters related to the heat treatment process of the workpiece, and output the correlation analysis results.

[0062] PLC module: Selectively triggers alarms from the alarm module and regulates the working status of the heat treatment equipment based on the correlation analysis results.

[0063] The process data of the heat treatment equipment includes: the actual heating temperature of the area where the workpiece is heat treated within the heat treatment equipment; and the workpiece parameters, including the workpiece temperature.

[0064] This may also include:

[0065] Process Management Module: Used to set the process and parameters for workpieces that need to be processed by the intelligent heat treatment production line of box furnace;

[0066] The PLC module obtains the working status data and process data of each heat treatment equipment in the intelligent heat treatment production line of the box furnace through the communication network and self-diagnosis of the heat treatment equipment.

[0067] The data acquisition module obtains real-time working status data and process data of each heat treatment equipment in the intelligent heat treatment production line of the box furnace from the PLC module, and obtains workpiece parameters in the heat treatment equipment, and integrates them to form real-time production line data.

[0068] Production Scheduling Module: Users can log in to new production batches of workpieces on the intelligent heat treatment production line of the box furnace through the production scheduling module; the production scheduling module schedules each production batch in a timely manner according to the production task information of the intelligent heat treatment production line of the box furnace, and sends the scheduling-related instructions to the PLC module through the data acquisition module, transferring the production batch in process to each process node of the intelligent heat treatment production line of the box furnace; the production scheduling module also notifies the quality inspection department to conduct physical and chemical tests on the production batch in real time through the quality inspection module according to the status of the completed production tasks, and generates quality inspection reports and batch reports;

[0069] Intelligent scheduling module: Used to adjust the task status in real time based on the current production task information of the box furnace intelligent heat treatment production line and the changes in the working status of the heat treatment equipment in the data acquisition module.

[0070] This invention focuses on the analysis of relevant parameters for protection;

[0071] The beneficial effects of the above technical solution are as follows:

[0072] The data acquisition module simultaneously acquires real-time process data from the equipment (such as actual heating temperature) and workpiece parameters (such as workpiece temperature). Combined with material parameters related to the heat treatment process of the workpiece obtained by the parameter acquisition module, the correlation analysis module achieves full-dimensional data linkage between "equipment-workpiece-material". This linkage can accurately capture the dynamic laws of heat transfer and microstructure transformation during heat treatment, avoiding process deviations caused by the disconnect between real-time process data from the equipment (such as actual heating temperature) and workpiece parameter data, and significantly improving the consistency of the workpiece's performance (such as hardness, strength, and toughness) after heat treatment.

[0073] By acquiring workpiece material parameters for different temperature ranges, the system can dynamically adjust process strategies based on material properties (such as thermal conductivity) for different materials and temperature ranges, resulting in more precise heat treatment.

[0074] When the correlation analysis result is abnormal, the control alarm module will sound an alarm and mark the corresponding heat treatment equipment as abnormal (which can be controlled to suspend operation); when the correlation analysis result is normal, the corresponding heat treatment equipment will be marked as normal.

[0075] This invention solves the problem raised in the background technology that "the relevant parameters of the heat treatment furnace (such as furnace temperature) and the workpiece temperature are not correlated and analyzed, making it impossible to assess the compatibility between the relevant parameters of the heat treatment furnace (such as furnace temperature) and the workpiece temperature, which can easily affect the heat treatment effect of the workpiece".

[0076] Example 2, based on Example 1, includes the following material parameters related to the heat treatment process of the workpiece: heat treatment time-standard workpiece temperature fitting curve corresponding to the heat treatment process of the workpiece and temperature range-thermal expansion coefficient-thermal conductivity mapping table corresponding to the process of the workpiece.

[0077] The heat treatment time-standard workpiece temperature fitting curve is divided into multiple temperature segments, each with continuous temperature. The ratio of the maximum to the minimum slope of each temperature segment satisfies a corresponding range. This ratio constrains the fluctuation range of the temperature change rate within that segment. Process stages with similar temperature change rate fluctuations are grouped into the same temperature segment to ensure that the "temperature change state" within each segment is relatively similar.

[0078] The correlation analysis module includes:

[0079] Calculation Unit 1: Used to calculate the rate of change of workpiece temperature based on workpiece temperature; the rate of change of workpiece temperature is calculated by "the difference between two adjacent workpiece temperature measurements ÷ the time difference between two adjacent workpiece temperature measurements".

[0080] Analysis Unit 1: Determine the equivalent thermal stress change based on the coefficient of thermal expansion, the rate of temperature change, and the modulus of elasticity of the workpiece within the current temperature range.

[0081] Analysis Unit 2: Determine the equivalent heat flux parameters based on the actual heating temperature change rate of the heat treatment area of ​​the workpiece within the heat treatment equipment, the specific heat capacity of the workpiece, and the heated surface area of ​​the workpiece;

[0082] Analysis Unit 3: Used to determine the heat flow-thermal stress interaction factor based on the equivalent thermal stress change, equivalent heat flow parameters, and thermal conductivity corresponding to the current workpiece temperature range;

[0083] The alarm module includes:

[0084] Alarm Unit 1: This unit is used to trigger an alarm when the rate of change of workpiece temperature is outside the preset range of the average rate of change of workpiece temperature in the corresponding temperature segment. First, the rate of change of temperature (curve slope) of each temperature segment in the "standard fitting curve" is calculated, and its average value is taken as the benchmark. Then, combined with the process stability requirements (such as allowing ±10% fluctuation), the "preset range" is defined.

[0085] Alarm Unit 2: This unit is used to issue an alarm when the heat flow-thermal stress interaction factor is outside the normal range (it can remind you to inspect the equipment or adjust the heat treatment process parameters). This range is the "safe range of the heat flow-thermal stress interaction factor" determined through experimental verification and engineering experience, based on the performance indicators of the workpiece material, structural design requirements, and industry defect control standards.

[0086] Equivalent thermal stress change = workpiece elastic modulus × coefficient of thermal expansion corresponding to the current workpiece temperature range × workpiece temperature change rate.

[0087] Equivalent heat flux parameter = (workpiece mass × workpiece specific heat capacity × actual heating temperature change rate of the area where the workpiece is heat-treated in the heat treatment equipment) ÷ workpiece heated area; the equivalent heat flux parameter quantifies the heat input intensity per unit area of ​​the workpiece.

[0088] Heat flow-thermal stress interaction parameter = ((equivalent thermal stress change + reference equivalent thermal stress change) × (equivalent heat flow parameter + median of the workpiece's allowable equivalent heat flow parameter range)) ÷ (maximum allowable value of equivalent thermal stress change × median of the workpiece's allowable equivalent heat flow parameter range) × (workpiece thermal conductivity);

[0089] Heat flow-thermal stress interaction factor = "workpiece heat flow-thermal stress interaction parameter" ÷ workpiece maximum allowable "heat flow-thermal stress interaction parameter";

[0090] The allowable range of equivalent heat flux parameters for a workpiece refers to the range within which the equivalent heat flux parameters are permissible, provided that the workpiece performance (such as no cracking or deformation, and meeting the requirements for strength, toughness, etc.) and process stability are guaranteed.

[0091] The process of obtaining the temperature range-thermal expansion coefficient-thermal conductivity mapping table corresponding to the process of the workpiece:

[0092] Perform segmented (temperature range) thermal expansion coefficient tests on the workpiece material (e.g., using a thermomechanical analyzer (TMA) to test the thermal expansion coefficient in different temperature ranges (e.g., room temperature to 300℃, 300 to 600℃, etc.); and simultaneously perform segmented thermal conductivity tests (e.g., using a laser scintillation method to test the thermal conductivity of the workpiece in different temperature ranges).

[0093] Organize the "temperature range - thermal expansion coefficient" and "temperature range - thermal conductivity" data obtained from the test, and establish a one-to-one mapping relationship (such as in the form of a table: temperature range → thermal expansion coefficient → thermal conductivity).

[0094] Standard temperature refers to the actual temperature of a workpiece during the entire heat treatment process, which is determined experimentally and allows the workpiece to achieve optimal heat treatment results in the current process (such as optimal core performance indicators like hardness, strength, toughness, and wear resistance, and the lowest deformation and defect rate).

[0095] The equivalent thermal stress change multiplied by the equivalent heat flux parameter represents the coupling between thermal stress and heat flux. If the heat flux input is strong (large heat flux parameter) and the thermal stress changes rapidly (large thermal stress change), the product will increase significantly, indicating that the coupling effect between heat and force is intense, and the workpiece is at extremely high risk of cracking and deformation due to "thermal shock + stress mutation". "Multiplying by thermal conductivity" reflects the amplification / attenuation effect of the material on the coupling.

[0096] The beneficial effects of the above technical solution are as follows:

[0097] Establish a mapping table of "temperature range - thermal expansion coefficient (which can be a range or an experimentally determined average) - thermal conductivity (which can be a range or an experimentally determined average)" to break the limitation of "using average thermophysical parameters across the entire temperature range" in traditional processes.

[0098] The coupling quantification of heat flux and thermal stress is the first to quantitatively bind "dynamic changes in thermal stress" and "heat flux input intensity" through an "interaction factor," no longer controlling temperature or stress in isolation. For example, during the quenching process, the coupling relationship between the rate of change of thermal stress and the intensity of heat flux input can be monitored simultaneously, identifying the risk of "excessive heat input leading to thermal stress exceeding limits" in advance.

[0099] Early warning of the heat flow-thermal stress interaction factor can identify high-risk process conditions before workpieces crack.

[0100] Example 3, based on Example 1 or 2, further includes a device analysis module, which includes:

[0101] Thermal inertia analysis unit:

[0102] This is used to determine the time it takes for the working power to reach the temperature stabilization point and the actual heating temperature of the heat treatment area of ​​the workpiece when the temperature stabilizes, based on the actual heating temperature change of the heat treatment area of ​​the workpiece within the heat treatment equipment during the operation of the heat treatment equipment.

[0103] The thermal inertia characteristic coefficient and thermal inertia state coefficient of the heat treatment equipment are determined based on the time from the application of working power to temperature stabilization and the actual heating temperature of the workpiece heat treatment zone when the temperature stabilizes.

[0104] Sequence construction unit: used to construct a sequence of thermal inertia characteristic coefficients of the heat treatment equipment in chronological order based on the thermal inertia characteristic coefficients of the heat treatment equipment within the latest setting time period;

[0105] Thermal inertia variation analysis unit: used to determine the thermal inertia variation coefficient based on the thermal inertia characteristic coefficient sequence;

[0106] Curve construction unit: used to construct a working power-thermal inertia characteristic coefficient relationship model (which can be a discrete point set or a fitted curve) based on the thermal inertia characteristic coefficient of the heat treatment equipment within the latest set time period.

[0107] Thermal inertia gradient analysis unit: used to analyze the working power-thermal inertia characteristic coefficient relationship model to determine the thermal inertia gradient coefficient; divide the working power-thermal inertia characteristic coefficient relationship model into working power intervals to obtain multiple working power intervals, and calculate the thermal inertia gradient coefficient based on the thermal inertia gradient coefficient calculation formula for each working power interval;

[0108] Operating power range Thermal inertia gradient coefficient = ; for The corresponding thermal inertia characteristic coefficient; for The corresponding thermal inertia characteristic coefficient;

[0109] Based on the power segmentation requirements of the heat treatment process (such as the power range corresponding to the preheating section, heating section, and heat preservation section), the power range associated with the process is taken as the power interval (i.e., the power range of the preheating section is one power interval); if it is a different type of workpiece, the segmentation is based on the different types of workpieces.

[0110] Early warning unit 1: Used to issue an early warning when any of the thermal inertia state coefficient, thermal inertia variation coefficient, or thermal inertia gradient coefficient is outside the corresponding normal range.

[0111] The equipment analysis module also includes:

[0112] Decision unit: Used to determine the maximum allowable power for the next power adjustment based on the thermal inertia state coefficient when none of the warning units issue a warning.

[0113] During the operation of heat treatment equipment, the working power changes dynamically according to the heating requirements. The following is the determination of the thermal inertia characteristic coefficient corresponding to the new power each time the new power is applied (when the new power is applied to start working).

[0114] The thermal inertia characteristic coefficient corresponding to the current working power of the heat treatment equipment = the time from the current working power to the temperature stabilization ÷ |equivalent temperature difference corresponding to the current working power| ÷ the current working power;

[0115] The equivalent time corresponding to the current working power = the actual heating temperature of the workpiece heat treatment area when the current working power starts to be applied - the actual heating temperature of the workpiece heat treatment area when the current working power is applied until the temperature stabilizes;

[0116] Thermal inertia state coefficient = thermal inertia characteristic coefficient ÷ reference thermal inertia characteristic coefficient;

[0117] The reference thermal inertia characteristic coefficient is the thermal inertia characteristic coefficient calibrated when the heat treatment equipment leaves the factory;

[0118] Thermal inertia coefficient of variation = (maximum value of thermal inertia characteristic coefficient sequence - minimum value of thermal inertia characteristic coefficient sequence) × unit time ÷ time interval between the maximum value and the minimum value of thermal inertia characteristic coefficient sequence;

[0119] The thermal inertia characteristic coefficient describes the degree of slowness in the response of the heat treatment equipment to the temperature of the workpiece heat treatment zone from the "initial state" to the "steady state" under the action of heat input (working power).

[0120] The coefficient of variation of thermal inertia quantifies the rate of change of the characteristic coefficient of thermal inertia over a period of time.

[0121] The decision-making unit may adopt the following strategy: the following strategy shall be implemented only after the furnace temperature first reaches the set temperature (i.e., excluding the process of the furnace temperature first reaching the set temperature);

[0122] When the thermal inertia state coefficient ∈ (0, 0.8], the maximum allowable power for the next power adjustment is 1.13 to 1.18 times the current working power (based on the selection of thermal inertia gradient coefficient for different power ranges; the larger the thermal inertia gradient coefficient, the smaller the above multiple).

[0123] When the thermal inertia state coefficient ∈ (0.8, 1.2], the maximum allowable power for the next power adjustment is 1.1 to 1.13 times the current operating power;

[0124] When the thermal inertia state coefficient ∈ (1.2, 1.5], the maximum allowable power for the next power adjustment is 1.0 to 1.05 times the current operating power;

[0125] When the thermal inertia state coefficient is greater than 1.5, the power will not be adjusted again and an alarm will be triggered to remind the heat treatment equipment to be repaired.

[0126] Specifically, for each range of thermal inertia state coefficients, the specific power adjustment factor can be determined by combining the classification of thermal inertia gradient coefficients (e.g., low sensitivity, medium sensitivity, high sensitivity). For example:

[0127] When the thermal inertia state coefficient ∈ (0, 0.8] and the thermal inertia gradient coefficient is low-sensitivity, the maximum allowable power is 1.18 times the current power; when it is medium-sensitivity, the maximum allowable power is 1.15 times the current power; and when it is high-sensitivity, the maximum allowable power is 1.13 times the current power.

[0128] Meanwhile, for processes such as quenching that require extremely high temperature accuracy, the ratio can be reduced by 0.02 to 0.03 times from the above ratio to suit the process characteristics.

[0129] The beneficial effects of the above calculation scheme are as follows:

[0130] The thermal inertia characteristic coefficient allows for precise understanding of the equipment's thermal response characteristics at different operating power levels (such as the sluggishness of temperature stabilization at a certain power), providing a quantitative basis for process design. The thermal inertia state coefficient benchmarks the equipment's current thermal performance against the factory baseline, enabling timely detection of thermal performance drift (such as increased thermal inertia due to aging or scaling), thus preventing process defects caused by performance degradation. The thermal inertia variation coefficient captures the dynamic rate of change in thermal inertia, identifying "sudden fluctuations" in equipment thermal performance (such as accelerated thermal inertia variation due to localized heating element failure), providing early warning of faults.

[0131] The early warning unit monitors the range of "thermal inertia state coefficient and thermal inertia variation coefficient" and can promptly alarm when the thermal performance of the equipment exceeds the normal range, thus avoiding batch scrapping of workpieces due to abnormal thermal performance (such as insufficient quenching hardness, uneven annealing structure, etc.).

[0132] The power adjustment rules of the decision-making unit realize adaptive power decision based on the thermal state of the equipment: when the thermal inertia of the equipment is small (low state coefficient), it indicates that the thermal response is sensitive and the power can be appropriately increased to improve production efficiency; when the thermal inertia of the equipment is close to the critical value (high state coefficient), the power adjustment range is limited to ensure process stability.

[0133] By calculating the thermal inertia gradient coefficient, the change in thermal inertia characteristic coefficient corresponding to a unit change in operating power is quantified. This allows for precise identification of the differences in the sensitivity of thermal inertia to changes in operating power, providing a quantitative basis for formulating operating power adjustment strategies. For example, small-step power adjustments can be used in ranges where thermal inertia is highly sensitive to power changes to ensure stable thermal performance; while large-step power adjustments can be used in ranges where thermal inertia is not sensitive to power changes to improve process efficiency.

[0134] By dividing the working power range into sections based on the working power-thermal inertia characteristic coefficient relationship model, and combining this with the segmented requirements of different types of workpieces (corresponding to the workpieces heat-treated by the heat treatment equipment) (such as preheating section, heating section, and heat preservation section), the division of power ranges becomes more in line with actual production scenarios. This allows for the development of differentiated power control strategies for different process stages or different workpieces' thermal performance characteristics, further improving the accuracy and adaptability of the heat treatment process. It also facilitates the accurate location and early warning of abnormal thermal inertia conditions in different power ranges.

[0135] Simultaneously, it monitors and provides early warnings for the thermal inertia coefficient of state, thermal inertia coefficient of variation, and thermal inertia gradient coefficient, achieving comprehensive monitoring of the thermal performance of heat treatment equipment from three dimensions: static characteristics (coefficient of state), time-dimensional fluctuations (coefficient of variation), and power-dimensional sensitivity (gradient coefficient). Any indicator exceeding the normal range in any dimension will trigger a timely warning, effectively avoiding the limitations of monitoring a single indicator. This allows for more comprehensive and timely detection of abnormal equipment thermal performance, ensuring timely equipment maintenance and process adjustments, thereby improving the yield of heat-treated workpieces and reducing production risks and costs.

[0136] Example 4, based on any one of Examples 1-3,

[0137] Process data for heat treatment equipment with an internal working atmosphere also includes: gas parameters inside the furnace cavity of the heat treatment equipment, including: gas flow rate, gas pressure, air temperature, and concentration of the working atmosphere (such as protective atmosphere nitrogen).

[0138] It also includes a furnace cavity analysis module, which includes:

[0139] Gas pressure-velocity correlation analysis unit: used to determine velocity characteristic factors based on gas velocity and gas pressure inside the furnace cavity of heat treatment equipment;

[0140] Atmosphere Concentration Sequence Construction Unit: Used to obtain the effective atmosphere concentration within the latest atmosphere attention period (atmosphere attention period is the working time of the heat treatment equipment to be selected for evaluating atmosphere deviation), and construct the effective atmosphere concentration sequence of the heat treatment equipment in chronological order of timestamps.

[0141] Atmosphere Concentration Analysis Unit: Used to determine the rate of change of atmosphere concentration based on the atmospheric concentration sequence of the heat treatment equipment; perform difference operation (or derivative of fitted curve) on the concentration sequence, calculate the concentration change at adjacent time points (concentration at the next time point - concentration at the previous time point), divide by the time interval to obtain the calculation rate, and then calculate the average of the calculation rate to obtain the rate of change of atmosphere concentration.

[0142] Stage and Deviation Analysis Unit: Used to determine the heat treatment stage of the workpiece (such as heating stage, cooling stage, and heat holding stage) based on the workpiece temperature in the heat treatment equipment, and to determine the atmosphere concentration deviation coefficient by combining the workpiece heat treatment stage and the rate of change of atmosphere concentration.

[0143] Atmosphere concentration deviation coefficient = (the rate of change of the atmosphere concentration - the rate of change of the standard atmosphere concentration in the corresponding heat treatment stage) ÷ (the rate of change of the unit atmosphere concentration + the rate of change of the standard atmosphere concentration in the corresponding heat treatment stage).

[0144] The unit of concentration change rate is concentration units per minute; the concentration unit can be a percentage; the unit atmospheric concentration change rate is taken as 1, with the unit being concentration units per minute; the unit atmospheric concentration change rate is added above to avoid the denominator being 0;

[0145] Temperature-pressure correlation analysis unit: used to determine the temperature-pressure composite flow correction coefficient based on the air temperature and pressure inside the furnace cavity of the heat treatment equipment;

[0146] Early warning unit 2: Used to issue an early warning when the flow rate characteristic factor and the atmosphere concentration deviation coefficient are not within the corresponding normal range ("normal range" refers to a set of parameter ranges that can guarantee the quality of heat treatment, determined separately for the flow rate characteristic factor and the atmosphere concentration deviation coefficient in long-term process verification and actual production).

[0147] Flow rate determination unit: used to determine the target flow rate based on the flow velocity characteristic factor, atmosphere concentration deviation coefficient, and temperature-pressure composite flow rate correction coefficient;

[0148] The control module of the heat treatment equipment controls the actual working atmosphere flow rate of the heat treatment equipment to the target flow rate.

[0149] ;in, This refers to the air pressure under standard operating conditions. The flow rate under standard operating conditions; V is the flow rate characteristic factor; P is the gas flow rate inside the furnace cavity of the heat treatment equipment; V is the gas pressure inside the furnace cavity of the heat treatment equipment.

[0150] A represents the air temperature inside the furnace cavity of the heat treatment equipment. This refers to the air temperature inside the heat treatment furnace under standard operating conditions. This is the temperature and pressure combined flow rate correction coefficient;

[0151] "Standard operating conditions" are a set of "optimal process benchmarks" (a set of process parameters that can achieve the best balance between quality, efficiency and cost of the process, including standard flow rate and standard atmosphere concentration change rate) that are pre-set for the current heat treatment process of the workpiece (such as heating, heat preservation and cooling).

[0152] The combined effects of increased temperature and decreased air pressure were quantified. When the temperature increases or the air pressure decreases, the gas density changes, and the effective gas volume at the same flow rate also changes. The impact of this change on the flow rate requirement was quantified, and the gas flow rate was adjusted accordingly to avoid fluctuations in the heat treatment quality of the workpiece due to changes in gas density.

[0153] It reflects the matching status between the actual "flow rate-pressure" combination and the standard operating conditions, and quantifies the matching status between the effective gas transmission capacity under "flow rate-pressure" matching and the standard operating conditions.

[0154] ;

[0155] This is the atmospheric concentration deviation coefficient; The standard flow rate for the current stage of the current process for the current workpiece;

[0156] This is the first flow rate correction factor (with a value of 0.01 to 0.2). This is the second flow correction factor (with a value of 0.02 to 0.3).

[0157] Obtaining the first flow rate correction coefficient: For the same type of workpiece and the current process (if the atmosphere parameters differ at different stages of the same process, experiments can be conducted for each stage), a dedicated experiment is performed. Select samples of the same type of workpiece and set different atmosphere concentration variations on the current heat treatment equipment to obtain the corresponding atmosphere concentration deviation coefficient. Adjust the flow rate until the workpiece heat treatment quality meets the standards, and record the difference between the adjusted flow rate and the standard flow rate for the process. Plot a scatter plot with the atmosphere concentration deviation coefficient as the independent variable and the flow rate adjustment ratio as the dependent variable for fitting (linear fitting is acceptable). The correlation coefficient extracted from the fitted model is the first flow rate correction coefficient.

[0158] Obtaining the second flow correction coefficient: For the same type of workpiece and the current process, set different temperature and pressure combinations (e.g., high temperature and low pressure, normal temperature and normal pressure, low temperature and high pressure, etc.) and calculate the temperature and pressure composite correction coefficient. Adjust the flow rate until the workpiece heat treatment quality meets the standard, and record the difference between the adjusted flow rate and the standard flow rate of the process. Plot a scatter plot with the temperature and pressure composite correction coefficient as the independent variable and the flow rate adjustment ratio as the dependent variable, and perform a fit (linear fitting is acceptable). The correlation coefficient extracted from the fitted model is the second flow correction coefficient.

[0159] The beneficial effects of the above technical solution are as follows:

[0160] Through a complete process of "atmosphere concentration sequence construction - differential calculation - deviation coefficient analysis," the deviation between the rate of change of atmosphere concentration and the process standard is quantified. Combined with the flow correction coefficient, the incoming flow rate is dynamically adjusted to fundamentally avoid heat treatment defects in workpieces caused by atmosphere concentration fluctuations (such as oxidation caused by insufficient protective atmosphere, excessive diffusion layer caused by excessive reactive atmosphere, etc.). The temperature and pressure composite flow correction coefficient quantifies the combined effect of "temperature increase + gas pressure decrease" on gas density. By adjusting the flow rate, it compensates for the fluctuation of effective gas quantity caused by density changes, ensuring that the workpiece can obtain a stable atmosphere effect under different temperature and pressure conditions. The flow rate characteristic factor accurately reflects the matching state between the actual "flow rate-gas pressure" combination and the standard operating conditions, quantifies the deviation of the effective gas transmission capacity, and ensures that the atmosphere can be uniformly and efficiently distributed in the furnace cavity.

[0161] Based on the multi-unit collaboration of the "furnace cavity analysis module" (real-time monitoring and analysis of flow rate, concentration, temperature, and pressure), dynamic adjustment of atmosphere flow rate is achieved, significantly improving the automation level of the production process. Early warning unit two monitors the abnormal range of flow rate characteristic factors and atmosphere concentration deviation coefficients in real time. When parameters exceed the "quality acceptable range," an alarm is triggered promptly, prompting operators or the automatic control system to intervene in advance, avoiding workpiece scrapping and production interruptions due to continuous parameter deterioration, and significantly improving the continuity and stability of the process. Traditional heat treatment often uses "excessive gas supply" to ensure atmosphere effect; this solution, through precise flow correction, achieves on-demand supply of atmosphere resources, reducing atmosphere gas consumption costs.

[0162] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A box-type furnace intelligent heat treatment production line management system, characterized in that: include: Data acquisition module: used to acquire real-time process data and workpiece parameters of each heat treatment equipment in the intelligent heat treatment production line of box furnace; Parameter acquisition module: used to acquire material parameters related to the heat treatment process of the workpiece. The material parameters related to the heat treatment process include workpiece material parameters for different temperature ranges. The correlation analysis module is used to perform correlation analysis on the process data of the heat treatment equipment, the parameters of the workpiece in the heat treatment equipment, and the material parameters related to the heat treatment process of the workpiece, and output the correlation analysis results. PLC module: Selectively triggers alarms from the alarm module and regulates the working status of the heat treatment equipment based on the correlation analysis results.

2. The intelligent heat treatment production line management system for box furnaces according to claim 1, characterized in that: The process data of the heat treatment equipment includes: the actual heating temperature of the area where the workpiece is heat treated within the heat treatment equipment; and the workpiece parameters, including the workpiece temperature.

3. The intelligent heat treatment production line management system for box furnaces according to claim 1, characterized in that: The material parameters related to the heat treatment process of the workpiece include: the heat treatment time corresponding to the heat treatment process of the workpiece - the temperature fitting curve of the standard workpiece and the temperature range corresponding to the process of the workpiece - the coefficient of thermal expansion - the thermal conductivity mapping table. The heat treatment time-standard workpiece temperature fitting curve is divided into multiple temperature segments, each temperature segment is continuous, and the ratio of the maximum slope value to the minimum slope value of each temperature segment satisfies the corresponding ratio range. The correlation analysis module includes: Calculation Unit 1: Used to calculate the rate of change of workpiece temperature based on workpiece temperature; Analysis Unit 1: Determine the equivalent thermal stress change based on the coefficient of thermal expansion, the rate of temperature change, and the modulus of elasticity of the workpiece within the current temperature range. Analysis Unit 2: Determine the equivalent heat flux parameters based on the actual heating temperature change rate of the heat treatment area of ​​the workpiece within the heat treatment equipment, the specific heat capacity of the workpiece, and the heated surface area of ​​the workpiece; Analysis Unit 3: Used to determine the heat flow-thermal stress interaction factor based on the equivalent thermal stress change, equivalent heat flow parameters, and thermal conductivity corresponding to the current workpiece temperature range.

4. The intelligent heat treatment production line management system for box furnaces according to claim 3, characterized in that: The alarm module includes: Alarm Unit 1: Used to issue an alarm when the rate of change of workpiece temperature is outside the preset range of the average rate of change of workpiece temperature in the corresponding temperature segment. Alarm Unit 2: Used to trigger an alarm when the heat flow-thermal stress interaction factor is outside the corresponding normal range.

5. The intelligent heat treatment production line management system for box furnaces according to claim 1, characterized in that: The PLC module obtains the working status data and process data of each heat treatment equipment in the intelligent heat treatment production line of the box furnace through the communication network and self-diagnosis of the heat treatment equipment. The data acquisition module obtains real-time operating status data and process data of each heat treatment equipment in the box furnace intelligent heat treatment production line from the PLC module, as well as obtains workpiece parameters in the heat treatment equipment, and integrates them to form real-time production line data.

6. The intelligent heat treatment production line management system for box furnaces according to claim 1, characterized in that: Also includes: Process Management Module: Used to set the process and parameters for workpieces that need to be processed by the intelligent heat treatment production line of box furnace.

7. The intelligent heat treatment production line management system for box furnaces according to claim 2, characterized in that: It also includes an equipment analysis module, which includes: Thermal inertia analysis unit: This is used to determine the time it takes for the working power to reach the temperature stabilization point and the actual heating temperature of the heat treatment area of ​​the workpiece when the temperature stabilizes, based on the actual heating temperature change of the heat treatment area of ​​the workpiece within the heat treatment equipment during the operation of the heat treatment equipment. The thermal inertia characteristic coefficient and thermal inertia state coefficient of the heat treatment equipment are determined based on the time from the application of working power to temperature stabilization and the actual heating temperature of the workpiece heat treatment zone when the temperature stabilizes. Sequence construction unit: used to construct a sequence of thermal inertia characteristic coefficients of the heat treatment equipment in chronological order based on the thermal inertia characteristic coefficients of the heat treatment equipment within the latest setting time period; Thermal inertia variation analysis unit: used to determine the thermal inertia variation coefficient based on the thermal inertia characteristic coefficient sequence; Curve construction unit: used to construct a working power-thermal inertia characteristic coefficient relationship model based on the thermal inertia characteristic coefficient of the heat treatment equipment within the latest set time period; Thermal inertia gradient analysis unit: used to analyze the working power-thermal inertia characteristic coefficient relationship model to determine the thermal inertia gradient coefficient; Early warning unit 1: Used to issue an early warning when any of the thermal inertia state coefficient, thermal inertia variation coefficient, or thermal inertia gradient coefficient is outside the corresponding normal range.

8. The intelligent heat treatment production line management system for box furnaces according to claim 7, characterized in that: The equipment analysis module also includes: Decision unit: Used to determine the maximum allowable power for the next power adjustment based on the thermal inertia state coefficient when none of the warning units issue a warning.

9. The intelligent heat treatment production line management system for box furnaces according to claim 2, characterized in that: The process data for heat treatment equipment with an internal atmosphere also includes: gas parameters inside the furnace cavity of the heat treatment equipment, including: gas flow rate, gas pressure, air temperature, and concentration of the atmosphere.

10. The intelligent heat treatment production line management system for box furnaces according to claim 9, characterized in that: It also includes a furnace cavity analysis module, which includes: Gas pressure-velocity correlation analysis unit: used to determine velocity characteristic factors based on gas velocity and gas pressure inside the furnace cavity of heat treatment equipment; Atmosphere Concentration Sequence Construction Unit: Used to obtain the latest atmospheric concentration within the attention period and construct the atmospheric concentration sequence of the heat treatment equipment in chronological order of timestamps. Atmosphere Concentration Analysis Unit: Used to determine the rate of change of atmosphere concentration based on the atmospheric concentration sequence of the heat treatment equipment. Stage and Deviation Analysis Unit: Used to determine the heat treatment stage of the workpiece based on the workpiece temperature in the heat treatment equipment, and to determine the atmosphere concentration deviation coefficient by combining the workpiece heat treatment stage and the rate of change of atmosphere concentration. Temperature-pressure correlation analysis unit: used to determine the temperature-pressure composite flow correction coefficient based on the air temperature and pressure inside the furnace cavity of the heat treatment equipment; Early warning unit 2: Used to issue an early warning when the flow rate characteristic factor and the atmosphere concentration deviation coefficient are not within the corresponding normal range; Flow rate determination unit: used to determine the target flow rate based on the flow velocity characteristic factor, atmosphere concentration deviation coefficient, and temperature-pressure composite flow rate correction coefficient; The control module of the heat treatment equipment controls the actual working atmosphere flow rate of the heat treatment equipment to the target flow rate.

Images