Resistance furnace vacuum system pressure control method

Abstract

This application belongs to the field of silicon carbide powder synthesis technology, specifically disclosing a pressure control method for a vacuum system of a resistance furnace, including the following steps: First, the current vacuum gauge monitors and obtains the monitored pressure value in real time; if the monitored pressure value reaches a preset switching value, the vacuum gauge to be switched is determined based on the monitored pressure value, and a target pressure value is set based on the vacuum gauge to be switched; then, a dynamic adjustment amount is calculated based on the monitored pressure value, the target pressure value, and a preset adjustment time; the over-pressure value is obtained by summing the dynamic adjustment amount and the monitored pressure value; if the difference between the over-pressure value and the target pressure value is greater than a preset difference, the over-pressure value is used as the output pressure value; otherwise, the vacuum gauge to be switched is updated to the current vacuum gauge, and its monitored pressure value is used as the output pressure value; finally, if it is necessary to control the gas pressure in the furnace cavity, PID control is performed based on the output pressure value. The method of this application can effectively reduce the PID control error during the vacuum gauge switching process.

Description

Technical Field

[0001] This application belongs to the field of silicon carbide powder synthesis technology, and more specifically, relates to a pressure control method for a vacuum system of a resistance furnace. Background Technology

[0002] When synthesizing silicon carbide powder using a resistance furnace, carbon powder and silicon powder are generally mixed in a certain proportion, placed in a crucible, and heated to sublimate and crystallize into silicon carbide powder. Before the equipment starts heating, a vacuum needs to be drawn to prevent gases such as oxygen and chlorine in the air from reacting with the carbon powder and silicon powder. At the same time, the furnace pressure also needs to be controlled during the synthesis. Pressure is an important parameter in the synthesis of silicon carbide powder, as it directly affects the powder density, strength, and particle size distribution. Therefore, a vacuum system is indispensable. When measuring different levels of gas pressure, multiple vacuum gauges with different ranges are usually required. When switching between vacuum gauges with different ranges, a pressure signal step will be generated. The pressure signal step will cause integral saturation, resulting in overshoot and oscillation in the pressure PID control (Proportional-Integral-Derivative Control), which leads to system instability and affects the synthesis yield of silicon carbide powder.

[0003] Currently, to address the impact of pressure signal step changes on pressure PID control, a slope function is typically used to process the pressure signal step, allowing the pressure signal to accumulate to the target value step by step, thus making the pressure signal change trajectory smooth. However, the intermediate transition pressure derived by this method cannot reflect the actual pressure change trend inside the resistance furnace, leading to errors in the pressure PID control during the smooth transition of the pressure signal. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the prior art, this application provides a pressure control method for a vacuum system of a resistance furnace, which aims to solve the technical problem of pressure PID control error caused by the pressure signal smoothing process in the existing pressure control method for a vacuum system of a resistance furnace.

[0005] To achieve the above objectives, in a first aspect, this application provides a pressure control method for a vacuum system of a resistance furnace, comprising: S1. The vacuum gauge is currently monitoring the gas pressure inside the furnace cavity in real time to obtain the monitored pressure value; S2. If the monitored pressure value reaches the preset switching value, the vacuum gauge to be switched is determined according to the changing trend of the monitored pressure value, and a target pressure value is set based on the vacuum gauge to be switched. S3. Calculate the dynamic adjustment amount based on the monitored pressure value, the target pressure value, and the preset adjustment time; S4. The excessive pressure value is obtained by summing the dynamic adjustment amount and the monitored pressure value; S5. If the difference between the excessive pressure value and the target pressure value is greater than the preset difference, the excessive pressure value is used as the output pressure value, the current vacuum gauge updates the monitored pressure value, and the process returns to step S3; otherwise, the vacuum gauge to be switched is updated to the current vacuum gauge, and the pressure value monitored by the current vacuum gauge is used as the output pressure value. S6. If it is necessary to control the gas pressure inside the furnace cavity, pressure PID closed-loop control is performed based on the output pressure value.

[0006] Preferably, the method for obtaining the preset switching value is as follows: obtain the range of all vacuum gauges in the furnace cavity that meet the preset accuracy, define the adjacent point value of adjacent ranges as the preset switching value, and define the point value in the intersection region of intersecting ranges as the preset switching value.

[0007] Preferably, the range of all vacuum gauges in the furnace cavity that meet the preset accuracy is obtained, and the value of a point in the intersection region of the intersecting ranges is defined as the preset switching value. Specifically, the median value of the intersection region of the intersecting ranges is defined as the preset switching value.

[0008] Preferably, if the monitored pressure value reaches a preset switching value, the vacuum gauge to be switched is determined based on the trend of the monitored pressure value, specifically: Obtain the range of all vacuum gauges in the furnace cavity that meet the preset accuracy; if the monitored pressure value continuously decreases to the preset switching value, determine that the vacuum gauge whose midpoint range is below the preset switching value and whose midpoint range is closest to the preset switching value is the vacuum gauge to be switched; If the monitored pressure value continuously rises to the preset switching value, it is determined that the midpoint of the range is above the preset switching value, and the vacuum gauge whose midpoint of the range is closest to the preset switching value is the vacuum gauge to be switched.

[0009] Preferably, a target pressure value is set based on the vacuum gauge to be switched, specifically: the pressure inside the furnace cavity monitored by the vacuum gauge to be switched at this time is used as a fixed target pressure value.

[0010] Preferably, the target pressure value is set based on the vacuum gauge to be switched, specifically: the pressure inside the furnace chamber monitored by the vacuum gauge to be switched at this time plus the expected pressure change is used as the fixed target pressure value.

[0011] Preferably, the target pressure value is set based on the vacuum gauge to be switched, specifically: the pressure inside the furnace cavity monitored in real time by the vacuum gauge to be switched is used as the target pressure value that changes over time.

[0012] Preferably, the dynamic adjustment amount is calculated based on the monitored pressure value, the target pressure value, and the preset adjustment duration, specifically as follows:

[0013] in, for The dynamic adjustment amount at any given time. For the target pressure value, for Real-time monitoring of pressure values, For time step, The preset adjustment duration.

[0014] Preferably, the dynamic adjustment amount is updated based on a preset adjustment range:

[0015] in, and These are the lower and upper limits of the dynamic adjustment range, respectively. for The dynamic adjustment amount at any given time.

[0016] Preferably, the excessive pressure value is obtained by summing the dynamic adjustment amount and the monitored pressure value, specifically as follows:

[0017] for The dynamic adjustment amount at any given time. For the present Real-time monitoring of pressure values, for The value of excessive stress at any given moment.

[0018] Preferably, if the furnace cavity is in the vacuuming process before production synthesis, it is not necessary to control the gas pressure inside the furnace cavity; if the furnace cavity is in the production synthesis process, it is necessary to control the gas pressure inside the furnace cavity.

[0019] In a second aspect, this application provides an electronic device, comprising: at least one memory for storing a program; and at least one processor for executing the program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to execute the method described in the first aspect or any possible implementation thereof.

[0020] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) The pressure control method for the vacuum system of the resistance furnace in this application treats the step signal generated during the switching of the vacuum gauge in the furnace as a dynamic step that changes in real time with the vacuum system. Based on this dynamic step, the dynamic adjustment amount during the signal smoothing process is calculated. Then, the dynamic adjustment amount is combined with the dynamic pressure value to obtain the transition pressure for smoothing the dynamic step, and pressure PID control is performed based on this transition pressure. The transition signal obtained by this method can accurately reflect the real pressure change characteristics in the resistance furnace, thereby preventing overshoot and oscillation during the pressure PID closed-loop control process, which would lead to system instability and improve the yield of powder synthesis.

[0021] (2) In this application, the dynamic step is defined as the difference in gas pressure monitored in real time by the current vacuum gauge and the vacuum gauge to be switched. Compared with the fixed step in the existing method, the dynamic step defined in this application can better reflect the pressure change in the vacuum system.

[0022] (3) In this application, an adjustment range is preset to limit the dynamic adjustment amount, thereby avoiding the generation of a large step size during the smooth transition of the signal, which in turn affects the pressure PID closed-loop control. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the hardware composition of the resistance furnace vacuum system provided in the embodiments of this application.

[0024] Figure 2 This is a flowchart of the pressure control process for the vacuum system of the resistance furnace provided in an embodiment of this application.

[0025] Figure 3 This is a flowchart of the pressure control process of the resistance furnace vacuum system during the vacuum gauge switching process provided in the embodiments of this application.

[0026] Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] The terms "first" and "second," etc., used in the description and claims herein are used to distinguish different objects, not to describe a specific order of the objects. For example, "first vacuum gauge" and "second vacuum gauge," etc., are used to distinguish different vacuum gauges, not to describe a specific order of the vacuum gauges.

[0029] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0030] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple vacuum gauges means two or more vacuum gauges, etc.

[0031] The embodiments of this application are described below with reference to the accompanying drawings.

[0032] like Figure 1 The figure shows the implementation object of the control method of this application, the vacuum system of the resistance furnace for synthesizing silicon carbide powder. As can be seen from the figure, the gas charging device is installed in the upper part of the furnace cavity of the resistance furnace, and the gas extraction device is installed in the lower part of the furnace cavity, forming an atmosphere passage. Both the gas charging device and the gas extraction device are controlled by PLC (Programmable Controllers).

[0033] Pressure is a crucial parameter in the synthesis of silicon carbide powder, directly affecting its density, strength, and particle size distribution. Therefore, pressure monitoring and control are essential during the silicon carbide powder synthesis process. Due to the large pressure variation range required within the furnace cavity, three vacuum gauges with different ranges are installed vertically in the center of the furnace cavity to ensure accurate monitoring of the internal pressure across all pressure ranges. These gauges are equidistant from each other and measure the pressure in the center of the furnace cavity. To meet certain pressure measurement accuracy requirements, the first vacuum gauge (1) has a range of 100 mbar to 1333 mbar, the second vacuum gauge (2) has a range of 0.1 mbar to 100 mbar, and the third vacuum gauge (3) has a range less than or equal to 0.1 mbar. The pressure reading from the vacuum gauge within which the furnace cavity pressure falls corresponds to the pressure reading monitored by that gauge and is used in the pressure PID control.

[0034] During the synthesis of silicon carbide powder, a vacuum process is required to ensure that carbon and silicon elements do not react with reactive gases such as oxygen and hydrogen in the air. First, start the vacuum device to pre-evacuate the furnace cavity. When the pressure inside the furnace cavity is lower than 5×10 -5 mbar; turn off the evacuation device, keep the furnace cavity in a static state, and check for leaks for 30 minutes, ensuring that the pressure rise rate of the furnace cavity during leak detection is less than 0.0005 mbar / min; once the equipment meets the vacuum requirements, the production process can begin. After completing the vacuuming process, proceed with the production process: The gas filling device is activated to inject inert gas into the furnace cavity, and the gas extraction device is activated at the same time to control the pressure inside the furnace cavity. In the powder synthesis process, the pressure control range is 3-850 mbar.

[0035] In the vacuuming and production processes, the pressure values ​​inside the furnace cavity vary greatly. Therefore, to ensure accurate gas pressure monitoring, a first vacuum gauge 1, a second vacuum gauge 2, and a third vacuum gauge 3 are used in conjunction to monitor the gas pressure inside the furnace cavity.

[0036] When the gas pressure in a furnace chamber crosses the range of different vacuum gauges, it is necessary to switch vacuum gauges to monitor the gas pressure. When switching vacuum gauges, a jump in the output pressure value will occur. A jump refers to the pressure value jumping from one value to another. The pressure jump signal is called a step signal. The step signal will cause overshoot and oscillation in the pressure PID control.

[0037] In vacuuming and production processes, the pressure control process of the vacuum system is as follows: Figure 2 As shown: First, the pressure switching value is set according to the range of multiple vacuum gauges. In this embodiment, under the condition of meeting a certain pressure measurement accuracy, the range of the first vacuum gauge 1 is 100mbar-1333mbar, and the range of the second vacuum gauge 2 is 0.1mbar-100mbar. Therefore, the pressure switching value between the first vacuum gauge 1 and the second vacuum gauge 2 is set to the intersection point value of the ranges of the first vacuum gauge 1 and the second vacuum gauge 2, that is, 100mbar.

[0038] The range of the second vacuum gauge 2 is 0.1 mbar to 100 mbar, and the range of the third vacuum gauge 3 is less than or equal to 0.1 mbar. Therefore, the pressure switching value between the second vacuum gauge 2 and the third vacuum gauge 3 is set to the intersection point value of the ranges of the second vacuum gauge 2 and the third vacuum gauge 3, which is 0.1 mbar.

[0039] Then, the pressure value inside the furnace cavity is monitored in real time, and the monitoring pressure value of the vacuum gauge that the current pressure value falls within is output.

[0040] If the monitored pressure value reaches the pressure switching value, the pressure smoothing process is initiated to achieve a smooth switching of the vacuum gauge. An excessive pressure value is output during the pressure smoothing process.

[0041] The real-time output pressure value is used in pressure PID control.

[0042] To mitigate the adverse effects of step signals, a pressure smoothing process is typically employed. However, existing pressure smoothing processes are based on mathematical procedures to smooth abrupt pressure signals. The resulting intermediate transition pressure values ​​fail to reflect the actual pressure change trend within the resistance furnace, leading to errors in the pressure PID control during the pressure signal smoothing transition process.

[0043] To address this problem, this application implements a novel method, such as Figure 3 As shown, the specific steps include: S1. The vacuum gauge is currently monitoring the gas pressure inside the furnace cavity in real time to obtain the monitored pressure value; In this embodiment, after the vacuuming process is started, since the range of the first vacuum gauge 1 is 133mbar-1333mbar, and the actual pressure value inside the furnace cavity is within this range, the first vacuum gauge 1 acts as the current vacuum gauge to monitor the gas pressure inside the furnace cavity in real time and obtain the monitored pressure value.

[0044] S2. If the monitored pressure value reaches the preset switching value, the vacuum gauge to be switched is determined according to the changing trend of the monitored pressure value, and a target pressure value is set based on the vacuum gauge to be switched. S21. During the continuous vacuuming process, the pressure inside the furnace cavity will continue to decrease until the monitoring pressure value detected by the first vacuum gauge 1 reaches the preset switching value.

[0045] The method for obtaining the preset switching value is as follows: obtain the range of all vacuum gauges in the furnace cavity, and set the value of adjacent points of adjacent ranges as the preset switching value, or set the value of one point in the intersection area of ​​intersecting ranges as the preset switching value.

[0046] In this embodiment, under the condition of meeting a certain air pressure measurement accuracy, the range of the first vacuum gauge 1 is 100mbar-1333mbar, and the range of the second vacuum gauge 2 is 0.1mbar-100mbar. Therefore, the preset switching value between the first vacuum gauge 1 and the second vacuum gauge 2 is set to the adjacent point value of the range of the first vacuum gauge 1 and the second vacuum gauge 2, that is, 100mbar.

[0047] The range of the second vacuum gauge 2 is 0.1 mbar-100 mbar, and the range of the third vacuum gauge 3 is less than or equal to 0.1 mbar. Therefore, the preset switching value between the second vacuum gauge 2 and the third vacuum gauge 3 is set to the adjacent point value of the ranges of the second vacuum gauge 2 and the third vacuum gauge 3, that is, 0.1 mbar.

[0048] In other embodiments, under the condition of meeting a certain pressure measurement accuracy, if the range of the first vacuum gauge 1 is 100 mbar-1333 mbar and the range of the second vacuum gauge 2 is 0.1 mbar-200 mbar, then the preset switching value between the first vacuum gauge 1 and the second vacuum gauge 2 is set to a value at a point in the intersection region of the ranges of the first vacuum gauge 1 and the second vacuum gauge 2. The intersection region is 100 mbar-200 mbar, and the preset switching value is set to a value of 158 mbar within the 100 mbar-200 mbar range. This method of setting a value at a point in the intersection region as the preset switching value is relatively flexible and suitable for determining the specific preset switching value based on the actual switching effect, in order to achieve a smooth and fast switching process.

[0049] In other embodiments, the median of the intersection region of the intersecting ranges is set as the preset switching value. That is, the median of 100mbar-200mbar, 150mbar, is set as the preset switching value. Setting the median of the intersection region as the preset switching value is a relatively simple method and generally achieves good switching results, making it suitable for setting the preset switching value for the first time.

[0050] S22. Determine the vacuum gauge to be switched based on the trend of the monitored pressure value: If the monitored pressure value continuously decreases to the preset switching value, then the vacuum gauge whose range midpoint is below the preset switching value and whose range midpoint is closest to the preset switching value is the vacuum gauge to be switched. If the monitored pressure value continuously rises to the preset switching value, it is determined that the midpoint of the range is above the preset switching value, and the vacuum gauge whose midpoint of the range is closest to the preset switching value is the vacuum gauge to be switched.

[0051] In this embodiment, the vacuum is gradually reduced from high pressure to low pressure. Therefore, the second vacuum gauge 2, whose midpoint range is below the preset switching value of 100 mbar and whose midpoint range is closest to 100 mbar, is determined as the vacuum gauge to be switched.

[0052] S23. Set the target pressure value based on the vacuum gauge to be switched: In this embodiment, the pressure inside the furnace cavity monitored in real time by the vacuum gauge to be switched is used as the target pressure value that changes over time, that is, the real-time monitoring pressure value of the second vacuum gauge 2 is used as the target pressure value. This method has the highest accuracy.

[0053] In other embodiments, the pressure inside the furnace cavity monitored by the vacuum gauge to be switched at this time is used as a fixed target pressure value. For example, the pressure inside the furnace cavity monitored by the second vacuum gauge 2 at this time, such as 98 mbar, is used as the fixed target pressure value. This method is suitable for situations where the preset adjustment time is short, and the pressure value monitored by the second vacuum gauge 2 does not change much after the preset adjustment time. This method is simple to calculate, but its accuracy is generally low.

[0054] In other embodiments, the pressure inside the furnace cavity monitored by the vacuum gauge to be switched at this time, plus the expected pressure change, is used as the fixed target pressure value. For example, the pressure inside the furnace cavity monitored by the second vacuum gauge 2 at this time, such as 98 mbar, is added to the pre-set expected pressure change - 1 mbar, resulting in a fixed target pressure value of 97 mbar. Here, the expected pressure change is the expected change in the monitored pressure value of the second vacuum gauge 2 during a preset adjustment period. This method is simple to calculate and its accuracy is further improved.

[0055] S3. Calculate the dynamic adjustment amount based on the monitored pressure value, the target pressure value, and the preset adjustment duration, specifically as follows:

[0056] in, for The dynamic adjustment amount at any given time. In this embodiment, the target pressure value is... Over time change, for Real-time monitoring of pressure values, For time step, The preset adjustment duration is used. In this application, the dynamic step... Defined as the real-time pressure difference between the current vacuum gauge and the vacuum gauge to be switched, the dynamic step defined in this application differs from the fixed step in existing methods. It is better able to reflect pressure changes within a vacuum system.

[0057] In this embodiment, to avoid large step sizes during signal smoothing and thus affecting the pressure PID closed-loop control, a preset adjustment range is designed to update the dynamic adjustment amount:

[0058] in, and These are the lower and upper limits of the dynamic adjustment range, respectively. for The dynamic adjustment amount at any given time.

[0059] S4. The excessive pressure value is obtained by summing the dynamic adjustment amount and the monitored pressure value; specifically:

[0060] for The dynamic adjustment amount at any given time. For the present Real-time monitoring of pressure values, for The value of excessive stress at any given moment.

[0061] S5. If the difference between the excessive pressure value and the target pressure value is greater than a preset difference, that is...

[0062] in, As a preset difference, in this embodiment, we set... .

[0063] The excessive pressure value is then used as the output pressure value. The current vacuum gauge updates the monitored pressure value and returns to step S3. When faced with the step signal generated during the switching process of the vacuum gauge inside the furnace, this application treats the step signal as a dynamic step that changes in real time with the vacuum system. Based on this dynamic step, the dynamic adjustment amount in the signal smoothing process is calculated. Then, by dynamic adjustment amount Combined with dynamic pressure values Obtain the excessive pressure of a smooth transition dynamic step. And based on this excessive pressure Pressure PID control is implemented. The transient signal obtained by this method can accurately reflect the actual pressure change characteristics in the resistance furnace, thereby preventing overshoot and oscillation during the pressure PID closed-loop control process, which could lead to system instability and improve the yield of powder synthesis.

[0064] Otherwise, the vacuum gauge to be switched will be updated to the current vacuum gauge, and the pressure value monitored by the current vacuum gauge will be used as the output pressure value; that is, the second vacuum gauge 2 will be used as the current vacuum gauge, and the pressure monitoring value of the second vacuum gauge 2 will be output.

[0065] S6. If it is necessary to control the gas pressure inside the furnace cavity, pressure PID closed-loop control is performed based on the output pressure value.

[0066] During the vacuuming process, there is no need to perform pressure PID closed-loop control of the gas pressure inside the furnace cavity.

[0067] During the production process, pressure PID closed-loop control of the gas pressure inside the furnace cavity is required.

[0068] Based on the methods in the above embodiments, this application provides an electronic device, such as... Figure 4 As shown, the electronic device may include a processor, a communications interface, a memory, and a communication bus, wherein the processor, communications interface, and memory communicate with each other via the communication bus. The processor can invoke logical instructions stored in the memory to execute the methods described in the above embodiments.

[0069] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0070] Based on the methods in the above embodiments, this application provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0071] Based on the methods in the above embodiments, this application provides a computer program product that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0072] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0073] The method steps in this application embodiment can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC.

[0074] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0075] It is understood that the various numerical designations used in the embodiments of this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application.

[0076] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method of pressure control for a resistance furnace vacuum system, characterized by, include: S1. The vacuum gauge is currently monitoring the gas pressure inside the furnace cavity in real time to obtain the monitored pressure value; S2. If the monitored pressure value reaches the preset switching value, the vacuum gauge to be switched is determined according to the changing trend of the monitored pressure value, and a target pressure value is set based on the vacuum gauge to be switched. S3. Calculate the dynamic adjustment amount based on the monitored pressure value, the target pressure value, and the preset adjustment duration; specifically: wherein, is a dynamic adjustment amount at the moment, is a target pressure value, is a monitored pressure value at the moment, is a time step, is a preset adjustment duration; The dynamic adjustment amount is updated based on the preset adjustment range: wherein, and are the lower and upper limits of the dynamic adjustment range, respectively, is the dynamic adjustment amount at the moment. S4. The excessive pressure value is obtained by summing the dynamic adjustment amount and the monitored pressure value; S5. If the difference between the excessive pressure value and the target pressure value is greater than the preset difference, the excessive pressure value is used as the output pressure value, the current vacuum gauge updates the monitored pressure value, and the process returns to step S3; otherwise, the vacuum gauge to be switched is updated to the current vacuum gauge, and the pressure value monitored by the current vacuum gauge is used as the output pressure value. S6. If it is necessary to control the gas pressure inside the furnace cavity, pressure PID closed-loop control is performed based on the output pressure value.

2. The pressure control method for the vacuum system of a resistance furnace according to claim 1, characterized in that, The method for obtaining the preset switching value is as follows: obtain the range of all vacuum gauges in the furnace cavity that meet the preset accuracy, define the adjacent point value of adjacent ranges as the preset switching value, and define the point value in the intersection region of intersecting ranges as the preset switching value.

3. The pressure control method for the vacuum system of a resistance furnace according to claim 1, characterized in that, If the monitored pressure value reaches the preset switching value, the vacuum gauge to be switched is determined based on the trend of the monitored pressure value, specifically: Obtain the measurement range of all vacuum gauges in the furnace cavity that meet the preset accuracy. If the monitored pressure value continuously decreases to the preset switching value, then the vacuum gauge whose range midpoint is below the preset switching value and whose range midpoint is closest to the preset switching value is the vacuum gauge to be switched. If the monitored pressure value continuously rises to the preset switching value, it is determined that the midpoint of the range is above the preset switching value, and the vacuum gauge whose midpoint of the range is closest to the preset switching value is the vacuum gauge to be switched.

4. The pressure control method for the vacuum system of a resistance furnace according to claim 1, characterized in that, The target pressure value is set based on the vacuum gauge to be switched, specifically: the pressure inside the furnace chamber monitored by the vacuum gauge to be switched at this time is used as the fixed target pressure value.

5. The pressure control method for the vacuum system of a resistance furnace according to claim 1, characterized in that, The target pressure value is set based on the vacuum gauge to be switched. Specifically, the target pressure value is the pressure inside the furnace chamber monitored by the vacuum gauge to be switched at this time plus the expected pressure change.

6. The pressure control method for the vacuum system of a resistance furnace according to claim 1, characterized in that, The target pressure value is set based on the vacuum gauge to be switched, specifically: the pressure inside the furnace chamber monitored in real time by the vacuum gauge to be switched is used as the target pressure value that changes over time.

7. The pressure control method for the vacuum system of a resistance furnace according to claim 1, characterized in that, The excessive pressure value is obtained by summing the dynamic adjustment amount and the monitored pressure value, specifically as follows: for The dynamic adjustment amount at any given time. For the present Real-time monitoring of pressure values, for The value of excessive stress at any given moment.

8. An electronic device, characterized in that, include: At least one memory for storing computer programs; At least one processor is configured to execute a program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to perform the method as described in any one of claims 1-7.

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