Electric control device and energy-saving control method of secondary degassing vacuum muffle furnace

Abstract

The application provides an electric control device and an energy-saving control method for a secondary degassing vacuum muffle furnace, and belongs to the technical field of powder metallurgy. The device comprises a PLC main controller, a vacuum degree detection module, a temperature detection module, a heating execution module and a vacuum unit control unit. The PLC main controller is used for: before starting the heating program, only when the real-time vacuum degree reaches or is better than the preset target vacuum degree, the starting enable of the heating execution module is unlocked; in the primary degassing stage, the vacuum unit control unit is controlled to run at a preset rotating speed, and the heating execution module is controlled to execute low-temperature baking with a temperature lower than a threshold value; in the secondary degassing stage, according to the acquired real-time temperature and real-time vacuum degree, the output power of the heating execution module and the running state of the vacuum unit control unit are cooperatively adjusted, so that the vacuum degree is stabilized at the preset reference vacuum degree while the energy consumption of the vacuum unit control unit is reduced. The application provides an electric control device and an energy-saving control method.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology, and particularly relates to an electrical control device and energy-saving control method for a secondary degassing vacuum muffle furnace. Background Technology

[0002] In powder metallurgy and new material research and development, vacuum muffle furnaces are used for heat treatment of materials in an oxygen-free and pollution-free environment. Degassing is a key process, typically requiring initial low-temperature baking to remove a large amount of adsorbed gas, followed by deep degassing at a higher temperature—a process known as secondary degassing. The electrical control system needs to coordinate temperature regulation, vacuum control, and the degassing process.

[0003] Existing electronic control solutions mostly use a single controller, which has two prominent problems: Firstly, if heating is started before the required vacuum level is reached, residual gas in the furnace reacts with the material, leading to material oxidation or performance degradation.

[0004] Secondly, during the secondary degassing stage, the vacuum unit operates continuously at full load and high speed to maintain the vacuum level, which not only wastes a lot of energy, but also lacks dynamic coordination between the high pumping speed and the heating power, which can easily induce drastic fluctuations in the vacuum level and affect the degassing quality. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes an electrical control device and energy-saving control method for a secondary degassing vacuum muffle furnace.

[0006] The first aspect of this invention provides an electrical control device for a secondary degassing vacuum muffle furnace, comprising: a PLC main controller, a vacuum degree detection module, a temperature detection module, a heating execution module, and a vacuum unit control unit; wherein: The vacuum detection module is used to collect the vacuum level inside the furnace in real time and transmit it to the PLC main controller; The temperature detection module is used to collect the temperature inside the furnace in real time and transmit it to the PLC main controller; The heating execution module is controlled by the PLC main controller; The vacuum unit control unit, which is connected to the PLC main controller, includes: a main pump for achieving vacuum and a pre-pump for front-stage pumping; The PLC main controller is used to: unlock the start-up enable of the heating execution module only when the real-time vacuum degree reaches or exceeds the preset target vacuum degree before the heating program starts; control the vacuum unit control unit to run at a preset speed during the first degassing stage, and control the heating execution module to perform low-temperature baking at a temperature below a threshold; during the second degassing stage, based on the acquired real-time temperature and real-time vacuum degree, coordinate the output power of the heating execution module and the operating state of the vacuum unit control unit to stabilize the vacuum degree near the preset reference vacuum degree while reducing the energy consumption of the vacuum unit control unit.

[0007] According to the electronic control device of the first aspect of the present invention, the vacuum unit control unit further includes: a frequency converter connected to the PLC main controller for driving the main pump and the pre-pump; The PLC main controller has a built-in allowable fluctuation range corresponding to the reference vacuum degree. During the secondary degassing stage, when the real-time vacuum degree exceeds the allowable fluctuation range, the PLC main controller starts the fuzzy PID controller. The deviation of the real-time vacuum degree from the reference vacuum degree and the real-time temperature are used as the input variables of the fuzzy PID controller. The output control quantity of the fuzzy PID controller is used to adjust the frequency of the frequency converter driver and compensate the power of the heating execution module.

[0008] According to the electronic control device of the first aspect of the present invention, the vacuum unit control unit further includes: a process formula storage module that communicates bidirectionally with the PLC main controller, used to: store the secondary degassing temperature curves and vacuum target curves of various materials, and a process formula composed of the secondary degassing temperature curves and vacuum target curves of different materials. The PLC main controller derives a transition criterion for the transition from primary to secondary degassing based on the invoked process formula. This transition criterion is based on at least one of the following settings: time, temperature, and vacuum change rate.

[0009] According to the electronic control device of the first aspect of the present invention, the vacuum unit control unit further includes: a host computer monitoring system connected to the PLC main controller via an industrial Ethernet, for displaying the trend curves of temperature, vacuum degree and power data of the vacuum unit control unit in real time, and accepting online modification of the set value of the reference vacuum degree by the operator.

[0010] According to the electronic control device of the first aspect of the present invention, the vacuum unit control unit further includes: an energy recovery unit connected in parallel in the heating circuit of the heating execution module; The energy recovery unit includes: a supercapacitor module and a bidirectional DC-DC converter; When the heating power drops sharply or the heating element generates energy feedback due to thermal inertia, the bidirectional DC-DC converter stores electrical energy in the supercapacitor module. When it is necessary to increase the heating power, the stored electrical energy is released first under the control of the PLC main controller to supply the heating circuit.

[0011] A second aspect of the present invention provides a method for energy-saving control using the aforementioned electronic control device, comprising: Step S1: Process initialization. The PLC main controller loads the process formula to determine the target vacuum degree, primary degassing temperature and holding time, and secondary degassing reference vacuum degree, target temperature and holding time. Step S2, Pre-evacuation and interlocking: Start the vacuum unit control unit to evacuate the vacuum. When the real-time vacuum level reaches or exceeds the target vacuum level, release the start enable of the heating execution module. Step S3: First degassing. The heating execution module is started to raise the furnace temperature to the first degassing temperature and keep it at that temperature. The vacuum unit control unit operates at the first power to perform degassing. Step S4: Secondary degassing transition determination. During the primary degassing and heat preservation stage, the PLC main controller periodically calculates the vacuum improvement per unit time. When the improvement is lower than the set threshold value for several consecutive cycles, it is determined to enter the secondary degassing stage. Step S5, Collaborative Energy Saving Control: After entering the secondary degassing stage, the PLC main controller uses the deviation between the real-time temperature and real-time vacuum degree and the reference vacuum degree as the input of the fuzzy PID controller. The fuzzy PID controller outputs a frequency control signal to adjust the frequency converter of the vacuum unit control unit to reduce the pump speed to the economic range required to maintain the reference vacuum degree. At the same time, it compensates the power of the heating execution module to offset the temperature fluctuation caused by the change in pumping speed. Step S6: The process is restored. After the target temperature for secondary degassing is reached and the heat preservation is completed, the heating execution module is turned off, and the vacuum unit control unit operates at the second power until cooling. The second power is less than the first power.

[0012] According to the method of the second aspect of the present invention, in step S5, the control rules of the fuzzy PID controller include at least: When the real-time vacuum level is worse than the reference vacuum level and the real-time temperature is greater than the target temperature for secondary degassing, reduce the frequency of the inverter driver and the heating power. When the real-time vacuum level is better than the reference vacuum level and the difference between the two is greater than the preset difference, the frequency of the inverter driver is increased to increase the pumping speed. When the deviation between the real-time vacuum degree and the reference vacuum degree and the rate of change of the deviation are both zero, the current frequency of the inverter driver and the heating power are maintained.

[0013] According to the method of the second aspect of the present invention, step S5 further includes an energy recovery step, wherein when the heating power drops instantaneously due to power compensation or over-temperature regulation, the supercapacitor module of the energy recovery unit connected in parallel in the heating circuit captures and stores the electrical energy fed back by the heating element; when the heating power needs to be increased instantaneously in the next control cycle, the electrical energy is preferentially released from the supercapacitor module for replenishment.

[0014] According to the method of the second aspect of the present invention, step S5 further includes a process self-learning step. After the same process recipe is run multiple times, the PLC main controller records the frequency adjustment process of the variable frequency drive and the corresponding energy consumption of the vacuum unit control unit in each run of the same process recipe. The membership function parameters of the fuzzy PID controller are adjusted by using an iterative learning algorithm so that the unit energy consumption of the same process recipe is gradually reduced in subsequent runs.

[0015] The solution proposed in this invention has the following technical effects: This invention implements a strict vacuum level attainment unlocking mechanism through a PLC main controller. During the secondary degassing stage, the PLC main controller coordinates the output power of the heating execution module and the operating status of the vacuum unit control unit based on the acquired real-time temperature and real-time vacuum level. This ensures that the vacuum level is stabilized near the preset reference vacuum level while reducing the energy consumption of the vacuum unit control unit.

[0016] Furthermore, during the secondary degassing stage, the present invention employs a fuzzy PID control strategy with real-time temperature and vacuum deviation as inputs to dynamically adjust the variable frequency speed of the vacuum pump unit to the economic range required to maintain the reference vacuum level. This completely changes the extensive mode of traditional vacuum units operating at full load throughout the entire process, significantly reducing the power consumption of the vacuum system. At the same time, temperature disturbances caused by changes in pumping speed are eliminated through heating power compensation.

[0017] In addition, the present invention captures thermal inertial feedback electrical energy through an energy recovery unit and prioritizes its reuse, thereby achieving peak shaving and valley filling and further improving the overall energy utilization efficiency of the machine.

[0018] Furthermore, this invention automatically determines the turning point to secondary degassing by periodically calculating the vacuum improvement per unit time using a PLC main controller, replacing manual experience-based judgment and ensuring thorough degassing between batches and process repeatability.

[0019] Furthermore, this invention uses an iterative learning algorithm to adaptively optimize the parameters of the fuzzy PID controller, enabling the unit energy consumption to gradually approach the optimal level after multiple runs of the same formula, thus endowing the equipment with continuous evolution capabilities. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a structural block diagram of the electrical control device for a secondary degassing vacuum muffle furnace according to one embodiment of the present invention.

[0022] Figure 2 This is a schematic flowchart illustrating an energy-saving control method for an electrical control device of a secondary degassing vacuum muffle furnace according to another embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The first aspect of this invention provides an electrical control device for a secondary degassing vacuum muffle furnace, such as... Figure 1 As shown, it includes: a PLC main controller, a vacuum degree detection module, a temperature detection module, a heating execution module, and a vacuum unit control unit. Among them: The vacuum detection module is used to collect the vacuum level inside the furnace in real time and transmit it to the PLC main controller.

[0025] The temperature detection module is used to collect the temperature inside the furnace in real time and transmit it to the PLC main controller.

[0026] The heating execution module is controlled by the PLC main controller.

[0027] The vacuum unit control unit, which is connected to the PLC main controller, includes a main pump for achieving vacuum and a pre-pump for upstream evacuation.

[0028] The PLC main controller is used to: unlock the start-up enable of the heating execution module only when the real-time vacuum degree reaches or exceeds the preset target vacuum degree before the heating program starts; control the vacuum unit control unit to run at a preset speed during the first degassing stage, and control the heating execution module to perform low-temperature baking at a temperature below a threshold; during the second degassing stage, based on the acquired real-time temperature and real-time vacuum degree, coordinate the output power of the heating execution module and the operating state of the vacuum unit control unit to stabilize the vacuum degree near the preset reference vacuum degree while reducing the energy consumption of the vacuum unit control unit.

[0029] In some embodiments, the vacuum unit control unit further includes: a frequency converter connected to the PLC main controller for driving the main pump and the pre-pump; The PLC main controller has a built-in allowable fluctuation range corresponding to the reference vacuum degree. During the secondary degassing stage, when the real-time vacuum degree exceeds the allowable fluctuation range, the PLC main controller starts the fuzzy PID controller. The deviation of the real-time vacuum degree from the reference vacuum degree and the real-time temperature are used as the input variables of the fuzzy PID controller. The output control quantity of the fuzzy PID controller is used to adjust the frequency of the frequency converter driver and compensate the power of the heating execution module.

[0030] In some embodiments, the vacuum unit control unit further includes: a process recipe storage module that communicates bidirectionally with the PLC main controller, used to: store the secondary degassing temperature curves and vacuum target curves of various materials, as well as the process recipes composed of the secondary degassing temperature curves and vacuum target curves of different materials. The PLC main controller derives a transition criterion for the transition from primary to secondary degassing based on the invoked process formula. This transition criterion is based on at least one of the following settings: time, temperature, and vacuum change rate.

[0031] In some embodiments, the vacuum unit control unit further includes: a host computer monitoring system connected to the PLC main controller via an industrial Ethernet, used to display the trend curves of temperature, vacuum degree and power data of the vacuum unit control unit in real time, and to allow the operator to modify the set value of the reference vacuum degree online.

[0032] In some embodiments, the vacuum unit control unit further includes: an energy recovery unit connected in parallel in the heating circuit of the heating execution module; The energy recovery unit includes: a supercapacitor module and a bidirectional DC-DC converter; When the heating power drops sharply or the heating element generates energy feedback due to thermal inertia, the bidirectional DC-DC converter stores electrical energy in the supercapacitor module. When it is necessary to increase the heating power, the stored electrical energy is released first under the control of the PLC main controller to supply the heating circuit.

[0033] A second aspect of the present invention provides a method for energy-saving control using the aforementioned electronic control device, such as... Figure 2 As shown. The method includes: Step S1: Process initialization. The PLC main controller loads the process formula to determine the target vacuum degree, primary degassing temperature and holding time, secondary degassing reference vacuum degree, target temperature and holding time.

[0034] Step S2, Pre-evacuation and interlocking: Start the vacuum unit control unit to evacuate the vacuum. When the real-time vacuum level reaches or exceeds the target vacuum level, deactivate the start enable of the heating execution module.

[0035] Specifically, after the process initialization in step S1 is completed, only the pre-vacuum pump runs in the pre-vacuum stage of step S2. The main pump is started only after the vacuum level reaches its starting condition. The PLC main controller compares the real-time vacuum level with the target vacuum level in the recipe. It must determine that the real-time vacuum level is equal to or better than, that is, less than or equal to, the target vacuum level before outputting the heating enable signal. This interlocking logic eliminates the hidden danger of heating when the vacuum level is not up to standard.

[0036] Step S3: First degassing. The heating execution module is started to raise the furnace temperature to the first degassing temperature and maintain the temperature. The vacuum unit control unit operates at the first power to perform degassing.

[0037] Specifically, after the heating execution module is started, the PLC main controller raises the furnace temperature to the primary degassing temperature according to the heating curve. At this time, the vacuum unit control unit runs at full speed, generating the maximum pumping speed, and a large amount of gas in the material is discharged. During the process, the PLC main controller records the vacuum degree and temperature data.

[0038] Step S4: Secondary degassing transition determination. During the primary degassing and heat preservation stage, the PLC main controller periodically calculates the vacuum improvement per unit time. When the improvement is lower than the set threshold value for several consecutive cycles, it is determined to enter the secondary degassing stage.

[0039] Specifically, during the first degassing and heat preservation stage, the PLC main controller continuously monitors the changes in vacuum level. For example, it calculates the improvement rate of vacuum level every 30 seconds. When the improvement rate is lower than a small threshold for five consecutive cycles, it indicates that the degassing rate has slowed down significantly and the second degassing fine-tuning stage has begun. This determination method effectively avoids the waste of quality or energy caused by early or late conversion.

[0040] Step S5: Collaborative energy-saving control. After entering the secondary degassing stage, the PLC main controller uses the deviation between the real-time temperature and real-time vacuum degree and the reference vacuum degree as the input of the fuzzy PID controller. The fuzzy PID controller outputs a frequency control signal to adjust the frequency converter of the vacuum unit control unit to reduce the pump speed to the economic range required to maintain the reference vacuum degree. At the same time, it compensates for the power of the heating execution module to offset the temperature fluctuation caused by the change in pumping speed.

[0041] Specifically, collaborative energy-saving control is the core. At this time, the PLC main controller executes energy-saving mode; it calculates the difference between the real-time vacuum level and the reference vacuum level, and combines this with the real-time temperature as input to the fuzzy PID controller. After fuzzy inference and declarative processing, the fuzzy PID controller outputs a frequency correction signal to the frequency converter driver, adjusting the main pump speed in real time. To overcome fluctuations in furnace heat loss that may be caused by changes in pumping speed, the feedforward compensation module estimates the change in heat dissipation based on frequency changes and fine-tunes the set power of the heating execution module in advance to keep the furnace temperature stable.

[0042] Step S6: Process recovery is completed. After the target temperature for secondary degassing is reached and the heat preservation is completed, the heating execution module is turned off, and the vacuum unit control unit operates at the second power until cooling. The second power is less than the first power.

[0043] Specifically, during the process recovery, heating stops after the heat preservation is completed, and the pump set switches to low speed to maintain a clean vacuum inside the furnace, cooling along with the furnace. During this process, the energy recovery unit can also recover some of the feedback electrical energy generated by heat loss for the control system's own use.

[0044] In some embodiments, the control rules of the fuzzy PID controller in step S5 include at least: When the real-time vacuum level is lower than the reference vacuum level and the real-time temperature is higher than the target temperature for secondary degassing, reduce the frequency of the inverter driver and the heating power.

[0045] When the real-time vacuum level is better than the reference vacuum level and the difference between the two is greater than the preset difference, the frequency of the inverter driver is increased to increase the pumping speed.

[0046] When the deviation between the real-time vacuum degree and the reference vacuum degree and the rate of change of the deviation are both zero, the current frequency of the inverter driver and the heating power are maintained.

[0047] Specifically, as an example of the fuzzy rule, if the vacuum deviation is negative and large, meaning the furnace pressure is significantly higher than the reference value and the temperature is too high, the pumping speed is significantly reduced and the heating power is appropriately decreased; if the vacuum deviation is positive and large, meaning the furnace pressure is too low, the pumping speed is increased first; when both the deviation and the rate of change are close to zero, the current output is maintained. In this way, while achieving the required vacuum level, the vacuum pump operates at the lowest possible speed, significantly reducing energy consumption.

[0048] In some embodiments, step S5 further includes an energy recovery step. When the heating power drops instantaneously due to power compensation or over-temperature regulation, the supercapacitor module of the energy recovery unit connected in parallel in the heating circuit captures and stores the electrical energy fed back by the heating element. When the heating power needs to be increased instantaneously in the next control cycle, the electrical energy is preferentially released from the supercapacitor module for replenishment.

[0049] Specifically, during the power compensation process, the energy recovery unit plays a role in peak shaving and valley filling. When the heating power drops momentarily due to compensation or overheating, the thermal inertia of the heating element will generate a brief reverse electrical energy. The bidirectional DC-DC converter captures this electrical energy and stores it in the supercapacitor module. When the next control cycle requires an increase in power, it will preferentially discharge from the supercapacitor, reducing the impact of instantaneous large currents from the grid and further saving energy.

[0050] In some embodiments, step S5 further includes a process self-learning step. After the same process recipe is run multiple times, the PLC main controller records the frequency adjustment process of the variable frequency drive and the corresponding energy consumption of the vacuum unit control unit during each run of the same process recipe. The membership function parameters of the fuzzy PID controller are adjusted using an iterative learning algorithm so that the unit energy consumption of the same process recipe is gradually reduced in subsequent runs.

[0051] Specifically, this invention features process self-learning optimization. In batch production, after the same formula process has been run multiple times, the PLC records the pumping speed and unit power consumption at each moment during the secondary degassing stage of each furnace. Through iterative learning algorithms, the shape or universe of discourse of the membership function in the fuzzy PID controller is automatically adjusted, so that the overall energy consumption of subsequent production at this stage tends to be optimal, thus achieving continuous improvement in control quality.

[0052] In summary, the solution proposed in this invention has the following technical effects: This invention implements a strict vacuum level attainment unlocking mechanism through a PLC main controller. During the secondary degassing stage, the PLC main controller coordinates the output power of the heating execution module and the operating status of the vacuum unit control unit based on the acquired real-time temperature and real-time vacuum level. This ensures that the vacuum level is stabilized near the preset reference vacuum level while reducing the energy consumption of the vacuum unit control unit.

[0053] Furthermore, during the secondary degassing stage, the present invention employs a fuzzy PID control strategy with real-time temperature and vacuum deviation as inputs to dynamically adjust the variable frequency speed of the vacuum pump unit to the economic range required to maintain the reference vacuum level. This completely changes the extensive mode of traditional vacuum units operating at full load throughout the entire process, significantly reducing the power consumption of the vacuum system. At the same time, temperature disturbances caused by changes in pumping speed are eliminated through heating power compensation.

[0054] In addition, the present invention captures thermal inertial feedback electrical energy through an energy recovery unit and prioritizes its reuse, thereby achieving peak shaving and valley filling and further improving the overall energy utilization efficiency of the machine.

[0055] Furthermore, this invention automatically determines the turning point to secondary degassing by periodically calculating the vacuum improvement per unit time using a PLC main controller, replacing manual experience-based judgment and ensuring thorough degassing between batches and process repeatability.

[0056] Furthermore, this invention uses an iterative learning algorithm to adaptively optimize the parameters of the fuzzy PID controller, enabling the unit energy consumption to gradually approach the optimal level after multiple runs of the same formula, thus endowing the equipment with continuous evolution capabilities.

[0057] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electrical control device for a secondary degassing vacuum muffle furnace, characterized in that, include: The system comprises a PLC main controller, a vacuum level detection module, a temperature detection module, a heating execution module, and a vacuum unit control unit; among which: The vacuum detection module is used to collect the vacuum level inside the furnace in real time and transmit it to the PLC main controller; The temperature detection module is used to collect the temperature inside the furnace in real time and transmit it to the PLC main controller; The heating execution module is controlled by the PLC main controller; The vacuum unit control unit, which is connected to the PLC main controller, includes: a main pump for achieving vacuum and a pre-pump for front-stage pumping; The PLC main controller is used to: unlock the start-up enable of the heating execution module only when the real-time vacuum degree reaches or exceeds the preset target vacuum degree before the heating program starts; control the vacuum unit control unit to run at a preset speed during the first degassing stage, and control the heating execution module to perform low-temperature baking at a temperature below a threshold; during the second degassing stage, based on the acquired real-time temperature and real-time vacuum degree, coordinate the output power of the heating execution module and the operating state of the vacuum unit control unit to stabilize the vacuum degree at the preset reference vacuum degree while reducing the energy consumption of the vacuum unit control unit.

2. The electronic control device according to claim 1, characterized in that, The vacuum unit control unit also includes: a frequency converter connected to the PLC main controller for driving the main pump and the pre-pump; The PLC main controller has a built-in allowable fluctuation range corresponding to the reference vacuum degree. During the secondary degassing stage, when the real-time vacuum degree exceeds the allowable fluctuation range, the PLC main controller starts the fuzzy PID controller. The deviation of the real-time vacuum degree from the reference vacuum degree and the real-time temperature are used as the input variables of the fuzzy PID controller. The output control quantity of the fuzzy PID controller is used to adjust the frequency of the frequency converter driver and compensate the power of the heating execution module.

3. The electronic control device according to claim 2, characterized in that, The vacuum unit control unit also includes: a process recipe storage module that communicates bidirectionally with the PLC main controller, used to: store the secondary degassing temperature curves and vacuum target curves of various materials, as well as process recipes composed of the secondary degassing temperature curves and vacuum target curves of different materials; The PLC main controller derives a transition criterion for the transition from primary to secondary degassing based on the invoked process formula. This transition criterion is based on at least one of the following settings: time, temperature, and vacuum change rate.

4. The electronic control device according to claim 3, characterized in that, The vacuum unit control unit also includes a host computer monitoring system connected to the PLC main controller via an industrial Ethernet, which is used to display the trend curves of temperature, vacuum degree and power data of the vacuum unit control unit in real time, and to allow the operator to modify the set value of the reference vacuum degree online.

5. The electronic control device according to claim 4, characterized in that, The vacuum unit control unit also includes an energy recovery unit connected in parallel in the heating circuit of the heating execution module; The energy recovery unit includes: a supercapacitor module and a bidirectional DC-DC converter; When the heating power drops sharply or the heating element generates energy feedback due to thermal inertia, the bidirectional DC-DC converter stores electrical energy in the supercapacitor module. When it is necessary to increase the heating power, the stored electrical energy is released first under the control of the PLC main controller to supply the heating circuit.

6. A method for energy-saving control using the electronic control device according to any one of claims 1-5, characterized in that, include: Step S1: Process initialization. The PLC main controller loads the process formula to determine the target vacuum degree, primary degassing temperature and holding time, and secondary degassing reference vacuum degree, target temperature and holding time. Step S2, Pre-evacuation and interlocking: Start the vacuum unit control unit to evacuate the vacuum. When the real-time vacuum level reaches or exceeds the target vacuum level, release the start enable of the heating execution module. Step S3: First degassing. The heating execution module is started to raise the furnace temperature to the first degassing temperature and keep it at that temperature. The vacuum unit control unit operates at the first power to perform degassing. Step S4: Secondary degassing transition determination. During the primary degassing and heat preservation stage, the PLC main controller periodically calculates the vacuum improvement per unit time. When the improvement is lower than the set threshold value for several consecutive cycles, it is determined to enter the secondary degassing stage. Step S5, Collaborative Energy Saving Control: After entering the secondary degassing stage, the PLC main controller uses the deviation between the real-time temperature and real-time vacuum degree and the reference vacuum degree as the input of the fuzzy PID controller. The fuzzy PID controller outputs a frequency control signal to adjust the frequency converter of the vacuum unit control unit to reduce the pump speed to the economic range required to maintain the reference vacuum degree. At the same time, it compensates the power of the heating execution module to offset the temperature fluctuation caused by the change in pumping speed. Step S6: The process is restored. After the target temperature for secondary degassing is reached and the heat preservation is completed, the heating execution module is turned off, and the vacuum unit control unit operates at the second power until cooling. The second power is less than the first power.

7. The method according to claim 6, characterized in that, In step S5, the control rules of the fuzzy PID controller include at least the following: When the real-time vacuum level is worse than the reference vacuum level and the real-time temperature is greater than the target temperature for secondary degassing, reduce the frequency of the inverter driver and the heating power. When the real-time vacuum level is better than the reference vacuum level and the difference between the two is greater than the preset difference, the frequency of the inverter driver is increased to increase the pumping speed. When the deviation between the real-time vacuum degree and the reference vacuum degree and the rate of change of the deviation are both zero, the current frequency of the inverter driver and the heating power are maintained.

8. The method according to claim 6, characterized in that, Step S5 also includes an energy recovery step. When the heating power drops instantaneously due to power compensation or over-temperature regulation, the supercapacitor module of the energy recovery unit connected in parallel in the heating circuit captures and stores the electrical energy fed back by the heating element. When the heating power needs to be increased instantaneously in the next control cycle, the electrical energy is released from the supercapacitor module to supplement it.

9. The method according to claim 8, characterized in that, Step S5 also includes a process self-learning step. After the same process recipe is run multiple times, the PLC main controller records the frequency adjustment process of the variable frequency drive and the corresponding energy consumption of the vacuum unit control unit during each run of the same process recipe. The membership function parameters of the fuzzy PID controller are adjusted using an iterative learning algorithm, so that the unit energy consumption of the same process recipe is gradually reduced in subsequent runs.

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