A multi-stage vacuum pumping intelligent control system and method

Abstract

This application relates to the field of industrial control technology, and provides a multi-stage intelligent vacuum control system and method. The system includes: a reaction vessel, a vacuum buffer tank, a vacuum pump unit, a vacuum regulating valve, a detection unit, and a control unit. The reaction vessel is connected to the vacuum buffer tank via the vacuum regulating valve, and the vacuum pump unit is also connected to the vacuum buffer tank. The detection unit includes a reaction vessel pressure sensor and a vacuum buffer tank pressure sensor; the reaction vessel pressure sensor collects the pressure of the reaction vessel, and the vacuum buffer tank pressure sensor collects the pressure of the vacuum buffer tank. The control unit coordinates the control of the vacuum pump unit and the vacuum regulating valve based on the stage control parameters corresponding to the current vacuum stage, the pressure of the reaction vessel, and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuum stage, and the pressure of the reaction vessel follows the pressure change of the vacuum buffer tank to the target pressure of the reaction vessel corresponding to the current vacuum stage.

Description

Technical Field

[0001] This application relates to the field of computer technology, and in particular to a multi-stage intelligent vacuum control system and method. Background Technology

[0002] Epoxy resin, as a high-performance synthetic resin, is widely used in many industries such as coatings, adhesives, composite materials, and electronic packaging. In its production process, the vacuum process is a key step to remove low-molecular-weight volatiles and bubbles in the system and improve the purity and performance of the product. The precise control of the vacuum degree directly determines the product quality and production efficiency of epoxy resin.

[0003] Currently, epoxy resin production in the fine chemical industry is developing towards automation, continuous production, and high precision, which places higher demands on the control accuracy, process stability, and energy consumption level of the vacuum process. Existing vacuum control methods in epoxy resin production typically rely on vacuum pump sets and pressure monitoring instruments.

[0004] However, in actual production processes, traditional vacuum control methods still rely heavily on manual experience for pump start-up and shutdown, operating frequency setting, and valve opening adjustment. When the pressure inside the reactor changes, the existing control methods struggle to dynamically adjust the operating parameters of the vacuum pump and vacuum regulating valves in a timely manner, which can easily lead to excessively rapid pressure drops, large pressure fluctuations, or unstable control of the target pressure at each stage. Summary of the Invention

[0005] In view of this, embodiments of this application provide a multi-stage intelligent vacuum control system and method to solve the problem in the prior art that the vacuum control process relies on human experience and is difficult to dynamically adjust the vacuum operation parameters according to the pressure changes of the reactor, resulting in poor stability of the vacuum process.

[0006] A first aspect of this application provides a multi-stage vacuuming intelligent control system, comprising: a reaction vessel, a vacuum buffer tank, a vacuum pump group, a vacuum regulating valve, a detection unit, and a control unit; the reaction vessel is connected to the vacuum buffer tank via the vacuum regulating valve, and the vacuum pump group is connected to the vacuum buffer tank; the detection unit includes a reaction vessel pressure detection element and a vacuum buffer tank pressure detection element, the reaction vessel pressure detection element being used to collect the pressure of the reaction vessel, and the vacuum buffer tank pressure detection element being used to collect the pressure of the vacuum buffer tank; the control unit is connected to the detection unit, the vacuum pump group, and the vacuum regulating valve respectively, and the control unit is used to coordinately control the vacuum pump group and the vacuum regulating valve according to the stage control parameters corresponding to the current vacuuming stage, the pressure of the reaction vessel, and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, and the pressure of the reaction vessel follows the pressure change of the vacuum buffer tank to the target pressure of the reaction vessel corresponding to the current vacuuming stage. A second aspect of this application provides a multi-stage intelligent vacuum control method, comprising: real-time acquisition of the pressure of a reactor and the pressure of a vacuum buffer tank; controlling a vacuum pump group to evacuate the vacuum buffer tank according to the stage control parameters corresponding to the current vacuum stage and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuum stage; controlling the opening of a vacuum regulating valve based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current vacuum stage, so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuum stage; after the current vacuum stage is completed, switching to the next vacuum stage, and continuing to perform vacuum control according to the stage control parameters corresponding to the next vacuum stage, until the vacuum control corresponding to multiple vacuum stages is completed.

[0007] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0008] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0009] The beneficial effects of this application embodiment compared with the prior art are as follows: The system of this application embodiment includes: a reaction vessel, a vacuum buffer tank, a vacuum pump group, a vacuum regulating valve, a detection unit, and a control unit; the reaction vessel is connected to the vacuum buffer tank through the vacuum regulating valve, and the vacuum pump group is connected to the vacuum buffer tank; the detection unit includes a reaction vessel pressure detection element and a vacuum buffer tank pressure detection element, the reaction vessel pressure detection element is used to collect the pressure of the reaction vessel, and the vacuum buffer tank pressure detection element is used to collect the pressure of the vacuum buffer tank; the control unit is connected to the detection unit, the vacuum pump group, and the vacuum regulating valve respectively, and the control unit is used to coordinately control the vacuum pump group and the vacuum regulating valve according to the stage control parameters corresponding to the current vacuuming stage, the pressure of the reaction vessel, and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, and the pressure of the reaction vessel follows the pressure change of the vacuum buffer tank to the target pressure of the reaction vessel corresponding to the current vacuuming stage. This application first controls the vacuum pump unit to evacuate the vacuum buffer tank based on the stage control parameters corresponding to the current vacuuming stage and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage. Then, based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current vacuuming stage, the opening of the vacuum regulating valve is controlled so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuuming stage. Thus, the vacuum buffer tank is used as a pressure buffer and pressure control object between the reactor and the vacuum pump unit, which can reduce the direct impact of changes in the pumping capacity of the vacuum pump unit on the reactor pressure and reduce the risk of sudden drops or drastic fluctuations in reactor pressure. Furthermore, since this application controls the process according to the stage control parameters corresponding to multiple vacuuming stages, and switches to the next vacuuming stage after the current vacuuming stage is completed, the reactor pressure can change step by step according to the target pressure of the reactor corresponding to different vacuuming stages, rather than changing rapidly to the final target pressure all at once. This better adapts to the process requirements of gradually increasing vacuum in epoxy resin production, and improves the stability and controllability of the vacuuming process. At the same time, this application collects the pressure of the reactor and the pressure of the vacuum buffer tank in real time, and controls the opening of the vacuum regulating valve based on the pressure deviation set value between the vacuum buffer tank and the reactor, so that the reactor pressure can follow the change under the traction of the vacuum buffer tank pressure.This improves the accuracy of reactor pressure control and reduces control lag and batch variations caused by manual adjustment of valve or pump frequency based on experience. Furthermore, the stage control parameters corresponding to the current vacuuming stage can be pre-configured and called, providing repeatable control basis for vacuuming processes in different batches and process stages. This helps improve the consistency of vacuuming processes and product quality stability in epoxy resin production, reduces the need for real-time manual intervention, and avoids the problem of poor stability in vacuuming processes caused by reliance on manual experience and difficulty in dynamically adjusting vacuuming parameters based on reactor pressure changes in related technologies. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a multi-stage intelligent vacuum control system provided in an embodiment of this application; Figure 2 This is a flowchart illustrating a multi-stage intelligent vacuum control method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0012] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, multi-stage vacuum intelligent control devices, circuits, and methods are omitted so as not to obscure the description of this application with unnecessary detail.

[0013] A multi-stage intelligent vacuum control system and method according to embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0014] Figure 1 This application provides a multi-stage intelligent vacuum control system, such as... Figure 1As shown, the system includes: a reaction vessel, a vacuum buffer tank, a vacuum pump unit, a vacuum regulating valve, a detection unit, and a control unit. The reaction vessel is connected to the vacuum buffer tank via the vacuum regulating valve, and the vacuum pump unit is also connected to the vacuum buffer tank. The detection unit includes a reaction vessel pressure sensor and a vacuum buffer tank pressure sensor. The reaction vessel pressure sensor is used to collect the pressure of the reaction vessel, and the vacuum buffer tank pressure sensor is used to collect the pressure of the vacuum buffer tank. The control unit is connected to the detection unit, the vacuum pump unit, and the vacuum regulating valve. The control unit is used to coordinately control the vacuum pump unit and the vacuum regulating valve according to the stage control parameters corresponding to the current vacuuming stage, the pressure of the reaction vessel, and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, and the pressure of the reaction vessel follows the pressure change of the vacuum buffer tank to the target pressure of the reaction vessel corresponding to the current vacuuming stage.

[0015] The reactor is used to contain the material to be vacuumed. The material to be vacuumed can be the reaction material in the epoxy resin production process, resin liquid, intermediate product, material system containing volatile components, material system containing water or low-boiling substances, or material system that needs to be degassed, devolatilized or depressurized during the vacuuming process. This application does not limit the scope of the material.

[0016] To avoid a sudden pressure drop inside the reactor caused by the vacuum pump unit directly acting on it, this embodiment introduces a vacuum buffer tank as an intermediate buffer container between the reactor and the vacuum pump unit. Specifically, the reactor has an exhaust port communicating with its gas phase space. The exhaust port can be located at the top of the reactor, on the upper side wall of the reactor, or as a suction port communicating with the gas phase space of the reactor. The exhaust port is connected to one end of a vacuum regulating valve via a suction pipeline, and the other end of the vacuum regulating valve is connected to the vacuum buffer tank; the suction end of the vacuum pump unit is connected to the vacuum buffer tank. Thus, an indirect vacuuming pipeline structure is formed in the physical flow path: reactor—vacuum regulating valve—vacuum buffer tank—vacuum pump unit.

[0017] The vacuum regulating valve is located between the reactor and the vacuum buffer tank to adjust the connection between them. When the vacuum regulating valve is open, the gas phase space inside the reactor is connected to the vacuum buffer tank, and the gas inside the reactor can enter the vacuum buffer tank through the vacuum regulating valve and be further extracted by the vacuum pump unit. When the vacuum regulating valve is closed or reduced in opening, it can restrict or cut off the gas flow between the reactor and the vacuum buffer tank, thereby preventing the reactor pressure from changing too quickly.

[0018] The vacuum buffer tank is mainly used to provide a gas-phase buffer space to reduce the instantaneous impact of changes in the pumping capacity of the vacuum pump group on the pressure of the reactor. It also allows the control unit to first adjust the pressure state of the vacuum buffer tank, and then make the reactor pressure follow the pressure change of the vacuum buffer tank through the vacuum regulating valve. The volume of the vacuum buffer tank can be determined according to the reactor volume, the pumping speed of the vacuum pump group, the target pressure corresponding to the vacuuming stage, the pressure ramp-up time, and the allowable pressure fluctuation range.

[0019] For example, when the reactor volume is large, the vacuum pump speed is high, or a long pressure ramp-up time is required during the vacuuming stage, a larger-volume vacuum buffer tank (e.g., the same volume as the reactor, or 50% of the reactor volume) can be selected to improve the buffering capacity of the vacuum buffer tank to pressure fluctuations. When the reactor volume is small, the vacuum pump speed is low, or the process allows for a large range of pressure fluctuations, a smaller-volume vacuum buffer tank (e.g., 40% or 30% of the reactor volume) can be selected. This application does not limit the specific volume ratio between the vacuum buffer tank and the reactor, as long as the vacuum buffer tank can form a gas phase space for pressure buffering and pressure regulation between the reactor and the vacuum pump group.

[0020] In some examples, the vacuum buffer tank may also be equipped with a gas-liquid separation structure, a liquid-blocking structure, a defoaming structure, a condensate collection section, or a drain port to reduce the amount of mist, condensate, or entrained material extracted from the reactor from entering the vacuum pump unit. The above structures can be configured according to the volatility and foaming properties of the epoxy resin production materials, as well as the protection requirements of the vacuum pump unit.

[0021] The control unit acquires the pressure of the vacuum buffer tank through a pressure sensor and the pressure of the reactor through a pressure sensor. It then coordinates the control of the vacuum pump unit and the vacuum regulating valve based on the stage control parameters corresponding to the current vacuuming stage. Specifically, the control unit first controls the vacuum pump unit to adjust the pressure of the vacuum buffer tank according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage. Then, based on the reactor pressure, the vacuum buffer tank pressure, and the pressure deviation corresponding to the current vacuuming stage, the control unit controls the opening of the vacuum regulating valve to ensure that the reactor pressure follows the pressure change of the vacuum buffer tank to the target reactor pressure corresponding to the current vacuuming stage.

[0022] With the above configuration, the vacuum buffer tank is not merely a simple connecting container, but rather serves as a pressure buffer and control element between the reactor and the vacuum pump unit. Compared to the method of the vacuum pump unit directly evacuating the reactor, this embodiment can reduce the risk of sudden pressure changes in the reactor, allowing the reactor pressure to gradually change according to the target pressure corresponding to multiple evacuation stages, thereby improving the stability and control accuracy of the evacuation process.

[0023] It is understandable that multiple vacuuming stages can be divided according to the gradual increase in vacuum required by the epoxy resin production process. For example, multiple vacuuming stages may include at least a first vacuuming stage, a second vacuuming stage, and a third vacuuming stage; the first vacuuming stage may correspond to the initial vacuuming stage with a lower vacuum level, the second vacuuming stage may correspond to the continued vacuuming stage with a medium vacuum level, and the third vacuuming stage may correspond to the deep vacuuming stage with a higher vacuum level.

[0024] According to the solution provided in the embodiments of this application, the system includes: a reaction vessel, a vacuum buffer tank, a vacuum pump group, a vacuum regulating valve, a detection unit, and a control unit; the reaction vessel is connected to the vacuum buffer tank through the vacuum regulating valve, and the vacuum pump group is connected to the vacuum buffer tank; the detection unit includes a reaction vessel pressure detection element and a vacuum buffer tank pressure detection element, the reaction vessel pressure detection element is used to collect the pressure of the reaction vessel, and the vacuum buffer tank pressure detection element is used to collect the pressure of the vacuum buffer tank; the control unit is connected to the detection unit, the vacuum pump group, and the vacuum regulating valve respectively, and the control unit is used to coordinately control the vacuum pump group and the vacuum regulating valve according to the stage control parameters corresponding to the current vacuuming stage, the pressure of the reaction vessel, and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, and the pressure of the reaction vessel follows the pressure change of the vacuum buffer tank to the target pressure of the reaction vessel corresponding to the current vacuuming stage. This application first controls the vacuum pump unit to evacuate the vacuum buffer tank based on the stage control parameters corresponding to the current vacuuming stage and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage. Then, based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current vacuuming stage, the opening of the vacuum regulating valve is controlled so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuuming stage. Thus, the vacuum buffer tank is used as a pressure buffer and pressure control object between the reactor and the vacuum pump unit, which can reduce the direct impact of changes in the pumping capacity of the vacuum pump unit on the reactor pressure and reduce the risk of sudden drops or drastic fluctuations in reactor pressure. Furthermore, since this application controls the process according to the stage control parameters corresponding to multiple vacuuming stages, and switches to the next vacuuming stage after the current vacuuming stage is completed, the reactor pressure can change step by step according to the target pressure of the reactor corresponding to different vacuuming stages, rather than changing rapidly to the final target pressure all at once. This better adapts to the process requirements of gradually increasing vacuum in epoxy resin production, and improves the stability and controllability of the vacuuming process. At the same time, this application collects the pressure of the reactor and the pressure of the vacuum buffer tank in real time, and controls the opening of the vacuum regulating valve based on the pressure deviation set value between the vacuum buffer tank and the reactor, so that the reactor pressure can follow the change under the traction of the vacuum buffer tank pressure.This improves the accuracy of reactor pressure control and reduces control lag and batch variations caused by manual adjustment of valve or pump frequency based on experience. Furthermore, the stage control parameters corresponding to the current vacuuming stage can be pre-configured and called, providing repeatable control basis for vacuuming processes in different batches and process stages. This helps improve the consistency of vacuuming processes and product quality stability in epoxy resin production, reduces the need for real-time manual intervention, and avoids the problem of poor stability in vacuuming processes caused by reliance on manual experience and difficulty in dynamically adjusting vacuuming parameters based on reactor pressure changes in related technologies.

[0025] In some examples, the system also includes a gas replenishment regulating valve, which is connected to the vacuum buffer tank and the control unit; the gas replenishment regulating valve is used to replenish the vacuum buffer tank with regulating gas under the control of the control unit to regulate the pressure change state of the vacuum buffer tank.

[0026] In other examples, the gas replenishment regulating valve can also be installed on the vacuum pipeline connected to the vacuum buffer tank, and regulating gas can be replenished to the vacuum buffer tank through the vacuum pipeline. That is to say, the gas replenishment regulating valve can be directly connected to the vacuum buffer tank, or it can be indirectly connected to the vacuum buffer tank through the vacuum pipeline, as long as it can replenish regulating gas to the vacuum buffer tank or the vacuum pipeline connected to it. This application does not limit this.

[0027] The regulating gas can be air, nitrogen, inert gas, or other gases suitable for epoxy resin production processes; this application does not limit this. The control unit can adjust the opening of the gas replenishment regulating valve based on the deviation between the vacuum buffer tank pressure collected by the vacuum buffer tank pressure detection device and the pressure control target corresponding to the current vacuuming stage.

[0028] Specifically, when the pressure in the vacuum buffer tank drops too quickly or the vacuum level is higher than the current control requirement, the control unit can increase the opening of the gas replenishment valve to increase the flow rate of the replenished regulating gas. Conversely, when the pressure in the vacuum buffer tank drops too slowly or the vacuum level is lower than the current control requirement, the control unit can decrease the opening of the gas replenishment valve to reduce the flow rate of the replenished regulating gas. This allows for correction of the pressure change process in the vacuum buffer tank, ensuring that the pressure in the vacuum buffer tank more smoothly approaches the target pressure corresponding to the current vacuuming stage.

[0029] In some examples, the pressure drop in the vacuum buffer tank may be too rapid, normal, or too slow, which can be determined based on the rate of change of the vacuum buffer tank pressure within a preset time window. For example, the control unit can acquire multiple vacuum buffer tank pressure samples within the preset time window, determine the rate of change of the vacuum buffer tank pressure based on these samples, and compare this rate of change with the target pressure rate of change corresponding to the current vacuuming stage to determine the pressure drop status of the vacuum buffer tank. The specific method by which the control unit controls the opening of the gas supply regulating valve based on this pressure drop status will be described in subsequent method embodiments and will not be repeated here.

[0030] In some examples, the vacuum pump assembly includes a variable frequency vacuum pump and at least one fixed frequency vacuum pump; the variable frequency vacuum pump is connected to the control unit via a frequency converter and is used to perform basic evacuation of the vacuum buffer tank under the control of the control unit; at least one fixed frequency vacuum pump is connected to the vacuum buffer tank and the control unit and is used to participate in evacuating the vacuum buffer tank under the control of the control unit.

[0031] For example, at least one fixed-frequency vacuum pump may include a two-stage fixed-frequency vacuum pump and / or a three-stage fixed-frequency vacuum pump. When a higher vacuum level is required during the current evacuation stage, or when the pressure of the reactor or the vacuum buffer tank reaches the preset fixed-frequency vacuum pump start-up conditions, the control unit can control the corresponding fixed-frequency vacuum pump to start, thereby improving the evacuation capability of the vacuum pump group for the vacuum buffer tank.

[0032] In some specific examples, a variable frequency vacuum pump can serve as the primary vacuum pump, while a secondary and tertiary fixed frequency vacuum pump can serve as secondary vacuum pumps. The primary vacuum pump provides the main pumping capacity during the first and second vacuuming stages and can continue operating during the third vacuuming stage; the secondary and / or tertiary fixed frequency vacuum pumps can be selectively activated based on stage control parameters, pump group start-up mode, and pressure threshold. Thus, the vacuum pump group can achieve continuous adjustment through the variable frequency vacuum pump and enhance the pumping capacity during the high vacuum stage through the activation of the fixed frequency vacuum pump.

[0033] Based on the same concept, this application also provides a multi-stage vacuum pumping intelligent control method, which is applied to the multi-stage vacuum pumping intelligent control system as described in any of the above embodiments, such as... Figure 2 As shown, the method includes: S201. Real-time acquisition of pressure in the reactor and vacuum buffer tank; S202. Based on the stage control parameters corresponding to the current vacuuming stage and the pressure of the vacuum buffer tank, control the vacuum pump group to evacuate the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage. S203. Based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation setting value corresponding to the current vacuuming stage, control the opening of the vacuum regulating valve so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuuming stage. S204. After the current vacuuming stage is completed, switch to the next vacuuming stage and continue vacuuming control according to the stage control parameters corresponding to the next vacuuming stage until the vacuuming control corresponding to multiple vacuuming stages is completed.

[0034] It is understood that the multi-stage vacuum pumping intelligent control method provided in this example can be executed by the aforementioned multi-stage vacuum pumping intelligent control system. Specifically, the method can be executed by the control unit in the multi-stage vacuum pumping intelligent control system. The control unit can be a PLC controller, DCS controller, industrial control computer, or other control equipment with logic operation and process control capabilities, and this application does not limit this.

[0035] In step S201, the control unit acquires the pressure of the reactor and the vacuum buffer tank in real time. Specifically, the multi-stage vacuum intelligent control system includes a detection unit, which comprises a reactor pressure detector and a vacuum buffer tank pressure detector. The reactor pressure detector is connected to the control unit and transmits the acquired reactor pressure to the control unit; the vacuum buffer tank pressure detector is connected to the control unit and transmits the acquired vacuum buffer tank pressure to the control unit. Thus, the control unit can acquire the pressure of the reactor and the pressure of the vacuum buffer tank and use them as feedback data for subsequent control of the vacuum pump group and vacuum regulating valve.

[0036] It is understood that in this application, the pressure of the reactor, the pressure of the vacuum buffer tank, the target pressure of the reactor, and the target pressure of the vacuum buffer tank can be gauge pressure values; when the pressure is a negative gauge pressure, the smaller the pressure value, the higher the vacuum degree. For example, -0.0800MPa has a higher vacuum degree than -0.0500MPa.

[0037] The pressure detection device for the reactor can be installed in the reactor body, the reactor gas phase space, the reactor exhaust port, or on a pressure detection pipeline connected to the reactor, for collecting the internal pressure of the reactor. Preferably, the pressure detection device is installed in a position connected to the reactor gas phase space so that the pressure it collects can reflect the actual pressure of the gas phase space inside the reactor.

[0038] The pressure detection device for the vacuum buffer tank can be installed on the vacuum buffer tank body, the vapor space of the vacuum buffer tank, or on a pressure detection pipeline connected to the vacuum buffer tank, for collecting the internal pressure of the vacuum buffer tank. Preferably, the pressure detection device is installed in a position connected to the vapor space of the vacuum buffer tank, so that the pressure it collects can reflect the actual pressure state inside the vacuum buffer tank.

[0039] In some examples, to improve the accuracy and reliability of pressure acquisition, multiple pressure sensors can be configured for the reactor, located at the reactor body, reactor exhaust port, or different pressure detection locations connected to the reactor. Similarly, multiple pressure sensors can be configured for the vacuum buffer tank, located at the vacuum buffer tank body or different pressure detection locations connected to the vacuum buffer tank. The control unit can perform averaging, weighting, redundancy checking, or anomaly removal processing on the pressure data acquired from the multiple pressure sensors to obtain the reactor pressure and vacuum buffer tank pressure used for control.

[0040] In some examples, the pressure sensors for the reactor and the vacuum buffer tank can acquire pressure data according to a preset acquisition period. For example, the preset acquisition period can be 0.5s, 1s, 2s, or other time intervals suitable for the accuracy requirements of vacuum control. The acquisition period of the reactor pressure sensor and the vacuum buffer tank pressure sensor can be the same or different. Preferably, the reactor pressure sensor and the vacuum buffer tank pressure sensor use the same acquisition period, for example, both acquiring pressure data with a 1s acquisition period, so that the control unit can synchronously obtain the reactor pressure and the vacuum buffer tank pressure and perform subsequent control based on the pressure relationship between them.

[0041] It should be noted that during the vacuuming process, the pressures of both the reactor and the vacuum buffer tank are dynamic pressure data that change over time, rather than fixed pressure values. As the vacuum pump unit evacuates the vacuum buffer tank, the pressure in the vacuum buffer tank changes gradually; as the vacuum regulating valve opens or adjusts, gas from the reactor enters the vacuum buffer tank through the vacuum regulating valve, and the pressure in the reactor also changes accordingly. Therefore, by collecting the reactor and vacuum buffer tank pressures in real time, real-time feedback data can be obtained during the vacuuming process.

[0042] Real-time feedback data can be used in at least two ways: First, the control unit can determine whether the vacuum buffer tank is changing according to the target pressure corresponding to the current vacuuming stage based on the pressure of the vacuum buffer tank, and control the vacuum pump unit's vacuuming capacity accordingly. Second, the control unit can control the opening of the vacuum regulating valve based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current vacuuming stage, so that the reactor pressure follows the pressure change of the vacuum buffer tank. Therefore, the pressure data collected by the detection unit forms the basis of closed-loop feedback in the multi-stage vacuuming control process.

[0043] In some examples, the stage control parameters corresponding to each vacuuming stage include, but are not limited to, the target pressure of the reactor, the target pressure of the vacuum buffer tank, the pressure deviation setpoint between the vacuum buffer tank and the reactor, the pressure ramp-up time, and the pressure holding time. The stage control parameters for different vacuuming stages can be different. The control unit first determines the current vacuuming stage and then calls up the stage control parameters corresponding to that stage.

[0044] Among them, the target pressure of the reactor is used to characterize the target pressure that the reactor needs to reach at the end of the current vacuuming stage; the target pressure of the vacuum buffer tank is used to characterize the target pressure that the vacuum buffer tank needs to reach or approach during the current vacuuming stage; the pressure deviation setting value is used to limit the pressure difference between the vacuum buffer tank and the reactor, so that the vacuum buffer tank can act as a vacuum source for the reactor and the reactor pressure can follow the pressure change of the vacuum buffer tank.

[0045] Understandably, during the vacuuming process, the vacuum level corresponding to the target pressure in the vacuum buffer tank is usually higher than that corresponding to the target pressure in the reactor. In other words, when using a negative pressure gauge to express the pressure, the target pressure in the vacuum buffer tank is lower than the target pressure in the reactor, so as to create the pressure difference required for gas flow between the reactor and the vacuum buffer tank.

[0046] Pressure ramp-up time indicates the time required for the vacuum buffer tank pressure to gradually change from the initial pressure of the current vacuuming stage to the target pressure of the vacuum buffer tank. Pressure holding time indicates the time the reactor pressure remains near the target pressure after reaching it for the current vacuuming stage. By setting the pressure ramp-up time and pressure holding time, the vacuuming process can be made to proceed at a preset rhythm, avoiding rapid pressure changes in the reactor.

[0047] For example, the multiple vacuuming stages may include a first vacuuming stage, a second vacuuming stage, and a third vacuuming stage. The first vacuuming stage, the second vacuuming stage, and the third vacuuming stage may correspond to different target pressures of the reactor, target pressures of the vacuum buffer tank, pressure deviation settings between the vacuum buffer tank and the reactor, pressure ramp-up time, and pressure holding time, respectively.

[0048] During the current vacuuming phase, the control unit determines whether the vacuum buffer tank pressure meets the pressure change requirements of the current vacuuming phase based on the phase control parameters and the pressure collected by the vacuum buffer tank pressure sensor. When the vacuum buffer tank pressure does not meet the control requirements of the current vacuuming phase, the control unit adjusts the vacuum pump group's vacuuming capacity to bring the vacuum buffer tank pressure towards the target pressure of the current vacuuming phase. Once the vacuum buffer tank pressure meets the control requirements of the current vacuuming phase, the control unit can maintain or limit the vacuum pump group's vacuuming capacity to keep the vacuum buffer tank pressure within the allowable range of the current vacuuming phase.

[0049] For example, in the first vacuuming stage, the control unit can control the vacuum pump group according to the lower target vacuum level corresponding to the first vacuuming stage, so that the pressure of the vacuum buffer tank gradually changes to the target pressure of the vacuum buffer tank corresponding to the first vacuuming stage; in the second vacuuming stage, the control unit calls the stage control parameters corresponding to the second vacuuming stage, so that the pressure of the vacuum buffer tank continues to change towards a higher vacuum level; in the third vacuuming stage, the control unit calls the stage control parameters corresponding to the third vacuuming stage, so that the pressure of the vacuum buffer tank further meets the process requirements of the high vacuum stage.

[0050] Therefore, different vacuuming stages do not use the same fixed control parameters for vacuuming. Instead, the control unit calls the corresponding stage control parameters according to the current vacuuming stage and controls the vacuum pump group in combination with the real-time pressure of the vacuum buffer tank. This makes the pressure of the vacuum buffer tank change gradually according to the target pressure corresponding to each vacuuming stage, thereby providing a stable vacuum source for the staged follow-up control of the reactor pressure.

[0051] In step S203, the control unit further controls the opening of the vacuum regulating valve based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation setting value corresponding to the current vacuuming stage, so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuuming stage.

[0052] Specifically, the vacuum buffer tank, acting as an intermediate vacuum source positioned between the reactor and the vacuum pump assembly, has its pressure controlled in step S202 to vary according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage. After obtaining the reactor pressure and the vacuum buffer tank pressure, the control unit can adjust the opening of the vacuum regulating valve based on the pressure relationship between the two and the pressure deviation set value corresponding to the current vacuuming stage, thereby controlling the gas flow between the reactor and the vacuum buffer tank.

[0053] When the vacuum regulating valve is open or at a corresponding opening degree, the gas inside the reactor can enter the vacuum buffer tank through the vacuum regulating valve and be further extracted by the vacuum pump unit, causing the reactor pressure to gradually change with the pressure in the vacuum buffer tank. When it is necessary to limit the rate of change of reactor pressure, the control unit can reduce the opening degree of the vacuum regulating valve to restrict the gas flow between the reactor and the vacuum buffer tank. Thus, the reactor pressure can gradually change to the corresponding target reactor pressure during the current vacuuming stage.

[0054] In step S204, after the current vacuuming stage is completed, the control unit switches to the next vacuuming stage and continues to perform vacuuming control according to the stage control parameters corresponding to the next vacuuming stage until the vacuuming control corresponding to multiple vacuuming stages is completed.

[0055] Specifically, the control unit can determine whether the current vacuuming stage is complete based on the pressure of the reactor, the target pressure of the reactor corresponding to the current vacuuming stage, and the pressure holding time. In some examples, when the pressure of the reactor reaches the target pressure of the reactor corresponding to the current vacuuming stage, and the pressure of the reactor remains within the allowable fluctuation range corresponding to the target pressure for a preset pressure holding time, the control unit determines that the current vacuuming stage is complete.

[0056] After the current vacuuming phase is completed, the control unit switches the phase identifier of the current vacuuming phase to the phase identifier of the next vacuuming phase and calls the phase control parameters corresponding to the next vacuuming phase. The phase control parameters corresponding to the next vacuuming phase may include one or more of the following: target pressure of the reactor, target pressure of the vacuum buffer tank, pressure deviation setpoint, pressure ramp-up time, pressure holding time, vacuum pump group operating parameters, and valve opening parameters.

[0057] After switching to the next vacuuming stage, the control unit continues to control the vacuum pump group to evacuate the vacuum buffer tank based on the real-time pressure of the reactor and the pressure of the vacuum buffer tank collected by the detection unit, and controls the opening of the vacuum regulating valve so that the pressure of the reactor continues to follow the pressure change of the vacuum buffer tank until the target pressure of the reactor corresponding to the next vacuuming stage is reached.

[0058] For example, the multiple vacuuming stages may include a first vacuuming stage, a second vacuuming stage, and a third vacuuming stage. When the first vacuuming stage is completed, the control unit switches to the second vacuuming stage and calls the stage control parameters corresponding to the second vacuuming stage; when the second vacuuming stage is completed, the control unit switches to the third vacuuming stage and calls the stage control parameters corresponding to the third vacuuming stage; when the third vacuuming stage is completed, the control unit determines that the vacuuming control corresponding to the multiple vacuuming stages is complete.

[0059] By using the above-mentioned stage switching method, the control unit can sequentially execute vacuum control according to the stage control parameters corresponding to multiple vacuum stages, so that the pressure of the reactor changes step by step according to the target pressure of different stages, avoiding rapid evacuation to the final target pressure in one go, thereby improving the stability of the vacuum process and the consistency of the process.

[0060] According to the scheme provided in this application, the pressure of the reactor and the pressure of the vacuum buffer tank are collected in real time; based on the stage control parameters corresponding to the current vacuuming stage and the pressure of the vacuum buffer tank, the vacuum pump group is controlled to evacuate the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage; based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current vacuuming stage, the opening of the vacuum regulating valve is controlled, so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuuming stage; after the current vacuuming stage is completed, the process switches to the next vacuuming stage and continues to perform vacuuming control according to the stage control parameters corresponding to the next vacuuming stage, until the vacuuming control corresponding to multiple vacuuming stages is completed. This application does not directly control the vacuum pump unit to evacuate the reactor. Instead, it first controls the vacuum pump unit to evacuate the vacuum buffer tank based on the stage control parameters corresponding to the current evacuation stage and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current evacuation stage. Then, based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current evacuation stage, it controls the opening of the vacuum regulating valve, so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current evacuation stage. Thus, the vacuum buffer tank is used as a pressure buffer and pressure control object between the reactor and the vacuum pump unit, which can reduce the direct impact of changes in the pumping capacity of the vacuum pump unit on the reactor pressure and reduce the risk of sudden pressure drop or drastic fluctuation in the reactor. Furthermore, since this application controls the process according to the stage control parameters corresponding to multiple vacuuming stages, and switches to the next vacuuming stage after the current vacuuming stage is completed, the reactor pressure can change step by step according to the target pressure of the reactor corresponding to different vacuuming stages, rather than changing rapidly to the final target pressure all at once. This better adapts to the process requirements of gradually increasing vacuum in epoxy resin production, and improves the stability and controllability of the vacuuming process. At the same time, this application collects the pressure of the reactor and the pressure of the vacuum buffer tank in real time, and controls the opening of the vacuum regulating valve based on the pressure deviation set value between the vacuum buffer tank and the reactor, so that the reactor pressure can follow the change under the traction of the vacuum buffer tank pressure. This improves the accuracy of reactor pressure control and reduces control lag and batch variations caused by manual adjustment of valve or pump frequency based on experience. Furthermore, the stage control parameters corresponding to the current vacuuming stage can be pre-configured and called, providing repeatable control basis for vacuuming processes in different batches and process stages. This helps improve the consistency of vacuuming processes and product quality stability in epoxy resin production, reduces the need for real-time manual intervention, and avoids the problem of poor stability in vacuuming processes caused by reliance on manual experience and difficulty in dynamically adjusting vacuuming parameters based on reactor pressure changes in related technologies.

[0061] In some examples, the vacuum pump unit is controlled to evacuate the vacuum buffer tank based on the stage control parameters corresponding to the current evacuation stage and the pressure of the vacuum buffer tank. This includes: determining the vacuum buffer tank pressure setpoint at the current moment based on the target pressure of the vacuum buffer tank corresponding to the current evacuation stage, the pressure ramp-up time, and the running time of the current evacuation stage; comparing the pressure of the vacuum buffer tank with the vacuum buffer tank pressure setpoint, and adjusting the operating frequency of the vacuum pump unit according to the comparison result, so that the vacuum pump unit evacuates the vacuum buffer tank.

[0062] The target pressure of the vacuum buffer tank corresponding to the current vacuuming stage is usually the stage target pressure that the vacuum buffer tank needs to reach at the end of the vacuuming stage. In order to determine the vacuuming effect of the current vacuuming stage at different operating times, the control unit can determine the vacuum buffer tank pressure setpoint corresponding to the current moment based on the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, the pressure ramp-up time, and the operating time of the current vacuuming stage.

[0063] It should be noted that the vacuum buffer tank pressure setpoint is not directly used as the closed-loop control target for the vacuum buffer tank pressure, but rather as a benchmark for judging the vacuum buffer tank's evacuation effect at the current moment. The control unit compares the actual pressure of the vacuum buffer tank collected by the vacuum buffer tank pressure sensor with the vacuum buffer tank pressure setpoint to determine whether the vacuum buffer tank has reached the required evacuation progress for the current evacuation stage.

[0064] In some examples, the vacuum buffer tank pressure setpoint for the current moment is determined based on the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, the pressure ramp-up time, and the running time of the current vacuuming stage. This includes: obtaining the stage start pressure of the current vacuuming stage, which is the pressure of the vacuum buffer tank at the beginning of the current vacuuming stage; and determining the vacuum buffer tank pressure setpoint for the current moment based on the stage start pressure, the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, the pressure ramp-up time, and the running time of the current vacuuming stage.

[0065] For example, during the pressure ramp-up process, the current vacuum buffer tank pressure setpoint can be determined according to the following relationship: ; in, The current vacuuming phase has been running for [time]. The corresponding vacuum buffer tank pressure setting value at that time. This is the initial pressure for the current vacuuming phase. This represents the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage. This refers to the pressure ramp-up time corresponding to the current vacuuming phase. This represents the running time during the current vacuuming phase, and .

[0066] When the running time reaches or exceeds the pressure ramp-up time, the control unit can determine the vacuum buffer tank pressure setpoint corresponding to the current moment as the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, that is: ; Therefore, during the pressure ramp-up period, the vacuum buffer tank pressure setpoint gradually changes from the initial pressure of the stage to the target pressure of the vacuum buffer tank; after the pressure ramp-up is completed, the vacuum buffer tank pressure setpoint remains at the target pressure of the vacuum buffer tank corresponding to that stage.

[0067] When using a negative pressure gauge to indicate pressure, if the actual pressure of the vacuum buffer tank is higher than the set pressure value, it means that the current vacuum level of the vacuum buffer tank is lower than the vacuuming requirement at the current moment. The control unit can control the vacuum pump group to continue vacuuming, or increase or maintain the vacuuming capacity of the vacuum pump group. If the actual pressure of the vacuum buffer tank is lower than or equal to the set pressure value, it means that the vacuuming effect of the vacuum buffer tank at the current moment has reached or exceeded the progress requirement of the current vacuuming stage. The control unit can maintain or limit the vacuuming capacity of the vacuum pump group.

[0068] Therefore, the vacuum buffer tank pressure setpoint is used to characterize the vacuuming effect judgment benchmark corresponding to the current vacuuming stage at the current operating time, so that the control unit can judge whether the pressure change of the vacuum buffer tank conforms to the preset ramping rhythm, thereby avoiding the vacuuming process being too fast or too slow due to judging only based on the final target pressure of the stage.

[0069] In some examples, the vacuum pump unit includes a variable frequency vacuum pump; the stage control parameters also include: an initial frequency setpoint and a target frequency setpoint; adjusting the operating frequency of the vacuum pump unit according to the comparison results so that the vacuum pump unit evacuates the vacuum buffer tank, including: determining the basic operating frequency of the variable frequency vacuum pump according to the initial frequency setpoint, target frequency setpoint, pressure ramp-up time, and the running time of the current evacuation stage; dynamically compensating and adjusting the basic operating frequency according to the comparison results to determine the target operating frequency including the variable frequency vacuum pump at the current moment, and controlling the variable frequency vacuum pump to evacuate according to the target operating frequency.

[0070] Specifically, the control unit can determine the frequency compensation coefficient based on the deviation between the actual pressure of the vacuum buffer tank and the set pressure value of the vacuum buffer tank, and multiply the basic operating frequency by the frequency compensation coefficient to obtain the compensated operating frequency. The frequency compensation coefficient can be greater than 1, equal to 1, or less than 1.

[0071] For example, when the actual pressure of the vacuum buffer tank is higher than the set pressure value, it indicates that the current vacuum level of the vacuum buffer tank is lower than the vacuuming requirement at the current moment. The control unit can set the frequency compensation coefficient to a value greater than 1, such as 1.1 or 1.2, to increase the operating frequency of the variable frequency vacuum pump. When the deviation between the actual pressure of the vacuum buffer tank and the set pressure value is within the allowable range, the control unit can set the frequency compensation coefficient to 1 so that the variable frequency vacuum pump operates at the basic operating frequency. When the actual pressure of the vacuum buffer tank is lower than the set pressure value, it indicates that the current vacuum level of the vacuum buffer tank has reached or exceeded the vacuuming requirement at the current moment. The control unit can set the frequency compensation coefficient to a value less than or equal to 1 to maintain or reduce the operating frequency of the variable frequency vacuum pump.

[0072] In some examples, the base operating frequency of the variable frequency vacuum pump is determined based on the initial frequency setting, target frequency setting, pressure ramp-up time, and the running time of the current vacuuming stage. This includes inputting the initial frequency setting, target frequency setting, pressure ramp-up time, and the running time of the current vacuuming stage into a parabolic model to obtain the base operating frequency. Parabolic models include: ; in, The running time for the current vacuuming phase is The basic operating frequency of the time-varying frequency vacuum pump Set the initial frequency value. Set a value for the target frequency. For pressure ramp-up time, and and Use the same unit of time.

[0073] In other examples, when the pressure ramp-up time is measured in minutes and the elapsed time of the current vacuuming phase is measured in seconds, the parabolic model can be represented as: ; in, The pressure ramp time is measured in minutes. The running time of the current vacuuming phase, expressed in seconds.

[0074] Using the parabolic model described above, the square of the frequency change of the variable frequency vacuum pump is correlated with the running time of the current vacuuming stage. This allows the operating frequency of the variable frequency vacuum pump to gradually change according to the pressure ramp-up requirements of the current vacuuming stage, thereby avoiding a rapid drop in the pressure of the vacuum buffer tank caused by sudden changes in the vacuum pump frequency.

[0075] In some examples, the vacuum pump assembly also includes at least one secondary fixed-frequency vacuum pump. During the process of controlling the vacuum pump assembly to evacuate the vacuum buffer tank, the control unit can also control the corresponding secondary fixed-frequency vacuum pump to start according to the pressure of the reactor, the current evacuation stage, and / or a preset secondary pump start threshold, so that the secondary fixed-frequency vacuum pump participates in evacuating the vacuum buffer tank.

[0076] In one embodiment, the control unit can compare the pressure of the reactor with a preset secondary pump start-up threshold; when the pressure of the reactor reaches or exceeds the secondary pump start-up threshold, it controls the corresponding secondary fixed-frequency vacuum pump to start. Wherein, when a negative pressure gauge is used to represent the pressure, reaching or exceeding the secondary pump start-up threshold may include the reactor pressure being less than or equal to the secondary pump start-up threshold.

[0077] In another embodiment, the control unit can control the secondary fixed-frequency vacuum pump to start according to the current vacuuming stage. For example, when the vacuuming process enters a preset high vacuum stage, the control unit controls the corresponding secondary fixed-frequency vacuum pump to start, so as to improve the pumping capacity of the vacuum pump group in this vacuuming stage. The high vacuum stage can be the second vacuuming stage, the third vacuuming stage, or other vacuuming stages that require improved pumping capacity, and this application does not limit it.

[0078] In another implementation, the control unit can combine the current vacuuming stage with the secondary pump start-up threshold for judgment. Specifically, the control unit can first determine whether the current vacuuming stage belongs to a preset vacuuming stage that allows the secondary fixed-frequency vacuum pump to start; if the current vacuuming stage belongs to the preset vacuuming stage, it further determines whether the pressure of the reactor reaches or exceeds the corresponding secondary pump start-up threshold; when both the current vacuuming stage and the reactor pressure meet the start-up conditions, the control unit controls the corresponding secondary fixed-frequency vacuum pump to start. This avoids the secondary fixed-frequency vacuum pump from starting prematurely in the low vacuum stage, while ensuring timely replenishment of pumping capacity in the high vacuum stage.

[0079] For example, at least one secondary fixed-frequency vacuum pump may include a second-stage fixed-frequency vacuum pump and a third-stage fixed-frequency vacuum pump. The control unit may, after entering the second or third vacuum stage, determine whether the reactor pressure has reached a preset second-stage pump start-up threshold; when the second-stage pump start-up threshold is reached, the control unit controls the second-stage fixed-frequency vacuum pump to start. The control unit may also, after entering the third vacuum stage, determine whether the reactor pressure has reached a preset third-stage pump start-up threshold; when the third-stage pump start-up threshold is reached, the control unit controls the third-stage fixed-frequency vacuum pump to start.

[0080] In some specific examples, the secondary fixed-frequency vacuum pump can be started when the reactor pressure reaches the target reactor pressure corresponding to the third vacuum stage, and the tertiary fixed-frequency vacuum pump can be started when the reactor pressure reaches the tertiary pump start-up threshold corresponding to a higher vacuum level. The aforementioned start-up stages and start-up thresholds can be configured as stage control parameters or pre-stored by the control unit; this application does not limit their specific configuration.

[0081] Therefore, the vacuum pump unit can mainly use the variable frequency vacuum pump to evacuate in the lower vacuum stage, and use the secondary fixed frequency vacuum pump to participate in the evacuation in the stage where a higher vacuum degree or greater pumping capacity is required, thereby improving the pumping capacity in the high vacuum stage and avoiding the increase in energy consumption or the rapid pressure change caused by the secondary fixed frequency vacuum pump starting too early.

[0082] In some examples, the multi-stage vacuum intelligent control system also includes a gas replenishment regulating valve connected to the vacuum buffer tank; the method further includes: dynamically adjusting the opening of the gas replenishment regulating valve according to the difference between the pressure of the vacuum buffer tank and the pressure set value of the vacuum buffer tank, so as to replenish the vacuum buffer tank with regulating gas to regulate the pressure change state of the vacuum buffer tank.

[0083] In this example, the control unit can determine the current vacuum buffer tank pressure setting based on the current vacuuming stage, the elapsed time of the current vacuuming stage, the target pressure of the reactor, and the pressure deviation setting, and then control the operating mode of the gas supply regulating valve according to the vacuum buffer tank pressure setting. The operating modes of the gas supply regulating valve include a fixed opening mode and an automatic adjustment mode.

[0084] Within a preset initial time after vacuuming starts, the control unit can keep the gas supply regulating valve in a fixed opening mode and gradually change the gas supply regulating valve from the initial opening to the transition opening according to a preset time relationship, so as to avoid sudden changes in the gas supply volume during the initial stage of vacuuming.

[0085] During the pressure ramp-up process of the first vacuuming stage, the control unit can determine the pressure setting value of the vacuum buffer tank at the current moment based on the vacuum buffer tank pressure at the beginning of the first vacuuming stage, the target pressure of the reactor corresponding to the first vacuuming stage, the pressure deviation setting value corresponding to the first vacuuming stage, the pressure ramp-up time corresponding to the first vacuuming stage, and the running time of the first vacuuming stage, and control the gas replenishment regulating valve to be in automatic adjustment mode.

[0086] For example, the pressure setpoint of the vacuum buffer tank at the current moment during the first vacuuming stage can be determined according to the following relationship: ； in, This is the pressure setpoint of the vacuum buffer tank at the current moment during the first vacuuming phase. This is the pressure in the vacuum buffer tank at the start of the first vacuuming stage. This represents the target pressure of the reactor corresponding to the first vacuuming stage. This is the pressure deviation setting value corresponding to the first vacuuming stage. This refers to the pressure ramp-up time corresponding to the first vacuuming stage. This represents the running time during the first vacuuming stage.

[0087] During the pressure holding process in the first vacuuming stage, the control unit can maintain the vacuum buffer tank pressure setpoint as follows: ; The system controls the gas supply regulating valve to be in automatic adjustment mode, allowing it to automatically adjust its opening based on the deviation between the actual pressure of the vacuum buffer tank and its set pressure value. In automatic adjustment mode, the control unit uses the current set pressure value of the vacuum buffer tank as the pressure reference value for the gas supply regulating valve control circuit, and uses the actual pressure of the vacuum buffer tank collected by the pressure sensor as the pressure feedback value. The control unit determines the adjustment amount of the gas supply regulating valve opening based on the pressure deviation between the set pressure value and the pressure feedback value, and adjusts the valve opening accordingly. Specifically, when using a negative pressure gauge to represent pressure, if the actual pressure of the vacuum buffer tank is lower than its set pressure value, it indicates that the vacuum level of the vacuum buffer tank is higher than the current vacuuming requirement. The control unit increases the opening of the gas supply regulating valve to increase the flow rate of regulating gas supplied to the vacuum buffer tank, thereby limiting the rapid decrease in the vacuum buffer tank pressure. When the actual pressure in the vacuum buffer tank is higher than the set pressure value, it indicates that the vacuum level in the vacuum buffer tank is lower than the vacuum requirement at the current moment. The control unit reduces the opening of the gas supply regulating valve to reduce the flow rate of regulating gas supplied to the vacuum buffer tank, allowing the vacuum pump unit to continue to increase the vacuum level in the vacuum buffer tank. When the pressure deviation between the actual pressure in the vacuum buffer tank and the set pressure value is within the preset allowable deviation range, the control unit maintains the current opening of the gas supply regulating valve or makes a slight correction to the opening of the gas supply regulating valve.

[0088] During the pressure ramp-up process in the second vacuuming stage, the control unit can gradually change the vacuum buffer tank pressure setpoint from the target pressure of the vacuum buffer tank corresponding to the first vacuuming stage to the target pressure of the vacuum buffer tank corresponding to the second vacuuming stage, and control the gas replenishment regulating valve to be in automatic adjustment mode. For example, the vacuum buffer tank pressure setpoint corresponding to the current moment in the second vacuuming stage can be determined according to the following relationship: ； in, This refers to the target pressure of the reactor corresponding to the second vacuuming stage. This is the pressure deviation setting value corresponding to the second vacuuming stage. This refers to the pressure ramp-up time corresponding to the second vacuuming stage. This represents the running time of the second vacuuming stage.

[0089] During the pressure holding or transition process in the second vacuuming stage, the control unit can gradually change the vacuum buffer tank pressure setpoint from the target pressure of the vacuum buffer tank corresponding to the second vacuuming stage to the target pressure of the vacuum buffer tank corresponding to the third vacuuming stage, and control the gas replenishment regulating valve to be in automatic adjustment mode, and adjust it in the same way as the above mode.

[0090] During the third vacuuming stage, the control unit can set the vacuum buffer tank pressure setpoint to the target pressure of the vacuum buffer tank corresponding to the third vacuuming stage, and control the gas supply regulating valve to be in a fixed opening mode, so that the gas supply regulating valve operates according to the gas supply valve set opening corresponding to the third vacuuming stage.

[0091] Through the above method, the gas replenishment regulating valve can be controlled in stages according to the vacuuming phase: the opening degree gradually changes during the initial startup phase; during the first and second vacuuming phases, it enters an automatic adjustment mode based on the vacuum buffer tank pressure setpoint; and during the third vacuuming phase, it operates at a fixed opening degree. This improves the stability of pressure changes in the vacuum buffer tank and provides a stable pressure base for the reactor pressure to follow changes in the vacuum buffer tank pressure.

[0092] In some examples, the opening of the vacuum regulating valve is controlled based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation setpoint corresponding to the current vacuuming stage. This includes: determining the actual pressure difference between the reactor pressure and the vacuum buffer tank pressure; determining the minimum safe pressure difference threshold based on the pressure deviation setpoint corresponding to the current vacuuming stage; when the actual pressure difference is greater than the minimum safe pressure difference threshold, controlling the vacuum regulating valve to remain open or adjust to the set opening to connect the reactor and the vacuum buffer tank; when the actual pressure difference is less than or equal to the minimum safe pressure difference threshold, controlling the vacuum regulating valve to decrease its opening or close. The actual pressure difference can be the difference between the reactor pressure and the vacuum buffer tank pressure.

[0093] In some examples, the control unit can invoke the corresponding minimum safe differential pressure threshold based on the current vacuuming stage. For instance, in the first vacuuming stage, the control unit determines a first minimum safe differential pressure threshold based on the pressure deviation setting corresponding to the first vacuuming stage; when the actual pressure difference between the reactor pressure and the vacuum buffer tank pressure is less than or equal to the first minimum safe differential pressure threshold, the control unit controls the vacuum regulating valve to decrease its opening or close. In the second vacuuming stage, the control unit determines a second minimum safe differential pressure threshold based on the pressure deviation setting corresponding to the second vacuuming stage; when the actual pressure difference is less than or equal to the second minimum safe differential pressure threshold, the control unit controls the vacuum regulating valve to decrease its opening or close.

[0094] If the aforementioned safety protection is not triggered, the control unit can control the operating mode of the vacuum regulating valve according to the current vacuuming stage. Specifically, during the first and second vacuuming stages, the control unit can control the vacuum regulating valve to enter an automatic adjustment mode, allowing the valve to adjust its opening according to the reactor pressure, the vacuum buffer tank pressure, and the stage pressure deviation. During the third vacuuming stage, or after the reactor pressure reaches the target reactor pressure corresponding to the third vacuuming stage, the control unit can control the vacuum regulating valve to enter a fixed opening mode and adjust it to the set opening corresponding to the third vacuuming stage.

[0095] In some examples, to avoid abrupt changes in the opening of the vacuum regulating valve, the control unit can delay, filter, or smooth the set opening of the vacuum regulating valve, and use the processed opening value as the actual control opening of the vacuum regulating valve. This can further reduce the risk of pressure fluctuations in the reactor caused by sudden changes in valve opening.

[0096] In this way, the vacuum regulating valve can not only adjust the connection between the reactor and the vacuum buffer tank, but also perform protective closure when the pressure difference between the reactor and the vacuum buffer tank is insufficient, thereby preventing uncontrolled changes in the reactor pressure.

[0097] In some examples, the system of this application also includes a human-machine interface unit (HMI) connected to the control unit. The HMI is used to receive stage control parameters input by the operator, or to recall pre-stored stage control parameters, and to send the stage control parameters to the control unit so that the control unit performs multi-stage vacuum control according to the stage control parameters.

[0098] The stage control parameters may include one or more of the following: target pressure of the reactor, target pressure of the vacuum buffer tank, pressure deviation setpoint, pressure ramp-up time, pressure holding time, vacuum pump group operating parameters, and valve opening parameters corresponding to multiple vacuum stages.

[0099] In some examples, the human-machine interface unit (HMI) may include an operator station, touchscreen, host computer, industrial computer, or other devices with HMI functionality. Operators can use the HMI to select the vacuuming formula to be executed, or input, modify, and save stage control parameters corresponding to different epoxy resin production grades. This allows different product grades or production batches to call upon corresponding vacuuming control parameters, improving the standardization of vacuuming process parameter settings.

[0100] In some examples, the human-machine interface unit is also used to display one or more of the following: pressure of the reactor, pressure of the vacuum buffer tank, current vacuuming stage, elapsed time of the current vacuuming stage, operating status of the vacuum pump group, opening degree of the vacuum regulating valve, opening degree of the gas replenishment regulating valve, and alarm information. Through these displays, operators can monitor the real-time operating status of the vacuuming process.

[0101] In some examples, the human-machine interface unit can also be used to display pressure change curves. These pressure change curves can include one or more of the following: reactor pressure curve, vacuum buffer tank pressure curve, vacuum buffer tank pressure setpoint curve, and reactor target pressure curve. Through these pressure change curves, operators can intuitively determine whether the vacuum buffer tank pressure and reactor pressure are operating according to the pressure change requirements corresponding to the current vacuuming stage.

[0102] In some examples, the human-machine interface unit can also be used to switch between automatic and manual control modes. In automatic control mode, the control unit automatically controls the vacuum pump group, vacuum regulating valve, and optional gas replenishment regulating valve according to the stage control parameters corresponding to the current vacuuming stage, the reactor pressure, and the vacuum buffer tank pressure. In manual control mode, the operator can input manual control commands through the human-machine interface unit to adjust the start / stop status of the vacuum pump group, the operating frequency of the variable frequency vacuum pump, and the opening degree of the vacuum regulating valve or the gas replenishment regulating valve.

[0103] In some examples, the human-machine interface unit can also be used to store and query historical vacuuming data. Historical vacuuming data may include one or more of the following: stage control parameters corresponding to different production batches, reactor pressure data, vacuum buffer tank pressure data, vacuum pump unit operating data, valve opening data, stage switching times, and alarm records. Storing and querying historical vacuuming data provides a data foundation for process traceability, parameter optimization, and anomaly analysis.

[0104] By setting up a human-machine interface unit, operators can configure parameters, monitor status, switch modes, and trace data for the multi-stage vacuuming control process, which helps to improve the automation level of the vacuuming process and the management level of process parameters.

[0105] To better understand this application, this embodiment provides a more specific example for illustration. It should be noted that the following parameters are merely exemplary parameters and do not constitute a limitation on the scope of protection of this application. In practical applications, they can be adjusted according to the reactor volume, material properties, target pressure, vacuum pump speed, and process requirements.

[0106] Please refer to Table 1 below, which shows an example of the configuration of a stage control parameter in an embodiment of this application.

[0107] Table 1: Parameter Configuration Table In this example, the multi-stage vacuum intelligent control system is an industrial automation control system that combines hardware and software. The system may include a detection unit, an execution unit, a control unit, and a human-machine interface unit, with electrical or communication connections between the units to form a closed-loop control system.

[0108] The detection unit may include reactor pressure sensors (such as reactor pressure sensors), vacuum buffer tank pressure sensors (such as vacuum buffer tank pressure sensors), and reactor temperature sensors. For example, the reactor pressure sensor may include PT_R110101A / B / C, the vacuum buffer tank pressure sensor may include PT_V110801A / B / C, and the reactor temperature sensor may include TT_P110801A / B / C. The detection unit is used to acquire reactor pressure, vacuum buffer tank pressure, and reactor temperature in real time. In some examples, the acquisition period for pressure and temperature data can be 1 second, the pressure detection range can be adapted to -0.1000MPa to 0.0000MPa, and the temperature detection range can be adapted to 0℃ to 100℃.

[0109] The execution unit may include a vacuum pump assembly, a vacuum frequency converter, a vacuum regulating valve, and a gas replenishment regulating valve. The vacuum pump assembly may include a primary pump, a secondary pump, and a tertiary pump. The primary pump can be a variable frequency vacuum pump, connected to the control unit via the vacuum frequency converter to achieve variable frequency speed regulation within the range of 0–50Hz; the secondary and tertiary pumps can be fixed frequency vacuum pumps, for example, operating at a fixed frequency of 50Hz. The start-up conditions for the secondary and tertiary pumps can be set through stage control parameters or recipe parameters.

[0110] The control unit can be a PLC controller, DCS controller, industrial control computer, or other control equipment with logic operation and process control capabilities. For example, the control unit can be a PLC controller with built-in multi-stage vacuum control logic. The control unit receives real-time data collected by the detection unit and outputs control signals to the vacuum pump group, vacuum frequency converter, vacuum regulating valve, and gas replenishment regulating valve according to the stage control parameters corresponding to the current vacuum stage, so as to realize the automatic adjustment of the vacuum process.

[0111] The human-machine interface unit (HMI) can include a control system operator station, operation panel, touch screen, or host computer. The HMI can be used for setting stage control parameters, displaying real-time data, monitoring curve trends, switching between manual and automatic modes, operating equipment start / stop, and saving historical process data.

[0112] In this example, the vacuuming process in epoxy resin production can be divided into a first vacuuming stage, a second vacuuming stage, and a third vacuuming stage. Each vacuuming stage is configured with corresponding target pressures for the reactor, vacuum buffer tank, pressure deviation settings, pressure ramp-up time, pressure holding time, pump operating parameters, and valve opening parameters. The control unit sequentially calls the corresponding stage control parameters according to the different vacuuming stages, causing the reactor pressure to gradually change to the target reactor pressure for each stage.

[0113] During the first vacuuming phase, the control unit starts the primary pump and controls it to operate at the initial frequency. Based on the target pressure of the reactor, the pressure deviation setpoint, the pressure ramp-up time, and the running time of the current phase corresponding to the first vacuuming phase, the control unit determines the pressure setpoint of the vacuum buffer tank at the current moment, and controls the vacuum pump group to evacuate the vacuum buffer tank, so that the pressure of the vacuum buffer tank gradually changes according to the pressure change requirements corresponding to the first vacuuming phase.

[0114] Simultaneously, the control unit collects the pressure of the reactor and the vacuum buffer tank in real time, and controls the opening of the vacuum regulating valve based on the pressure difference between the two and the pressure deviation set value corresponding to the first vacuuming stage, so that the reactor pressure follows the pressure change of the vacuum buffer tank. When the reactor pressure reaches the target reactor pressure corresponding to the first vacuuming stage, for example, -0.0500MPa, the control unit enters the pressure holding process of the first vacuuming stage, and maintains the reactor pressure within the allowable fluctuation range corresponding to the target pressure during the pressure holding time, for example, within the range of ±0.0050MPa of the target pressure.

[0115] During the second vacuuming phase, the control unit calls upon the phase control parameters corresponding to the second vacuuming phase after the first vacuuming phase is completed. The control unit can adjust the frequency of the primary pump from the operating frequency corresponding to the first vacuuming phase to the target frequency corresponding to the second vacuuming phase, and continue to control the pressure change of the vacuum buffer tank according to the target pressure, pressure deviation setpoint, and pressure ramp-up time of the vacuum buffer tank corresponding to the second vacuuming phase.

[0116] During this stage, the control unit controls the pressure relationship between the reactor and the vacuum buffer tank according to the pressure deviation setpoint corresponding to the second vacuuming stage. This ensures that the reactor pressure continues to follow the pressure changes in the vacuum buffer tank and gradually reaches the target reactor pressure corresponding to the second vacuuming stage, for example, -0.0800 MPa. After the reactor pressure reaches the target reactor pressure corresponding to the second vacuuming stage, the control unit enters the pressure holding process of the second vacuuming stage and maintains the reactor pressure within the corresponding allowable fluctuation range during the pressure holding time, for example, within the target pressure ±0.0030 MPa range.

[0117] During the third vacuuming stage, the control unit calls the corresponding stage control parameters after the second vacuuming stage is completed. The control unit can adjust the vacuum regulating valve to the set opening degree corresponding to the third vacuuming stage, and in combination with the operating status of the vacuum pump group and the opening degree of the gas supply regulating valve, further change the reactor pressure to the target reactor pressure corresponding to the third vacuuming stage, such as -0.0850MPa.

[0118] In some examples, if the recipe parameters are set to allow automatic start of the secondary pump, the control unit controls the secondary pump to start when the reactor pressure reaches the secondary pump start threshold, so that the secondary pump can participate in the vacuuming process.

[0119] In some examples, the secondary pump start-up threshold can be set to the target reactor pressure corresponding to the third vacuum stage. If the recipe parameters are set to allow automatic start-up of the tertiary pump, the control unit will activate the tertiary pump when the reactor pressure reaches the tertiary pump start-up threshold. For example, the tertiary pump start-up threshold can be set to -0.095 MPa. Thus, the vacuum pump unit can be activated step-by-step according to the vacuum stage and pressure conditions to meet the requirements of higher vacuum processes.

[0120] In some examples, the control unit can also adjust the control parameters for subsequent stages based on the actual operating results of each vacuuming stage. For instance, the control unit can collect the actual vacuuming time, the deviation between the actual reactor pressure and the target pressure, and the deviation between the vacuum buffer tank pressure and the pressure setpoint for each vacuuming stage, and adjust the pump frequency, vacuum regulating valve opening, or gas replenishment regulating valve opening based on the above data.

[0121] For example, when the actual vacuuming time in the first vacuuming stage is longer than the preset time, the control unit can increase the initial opening of the gas supply regulating valve, the target frequency of the primary pump, or other relevant operating parameters in subsequent batches or stages; when the actual vacuuming time in the first vacuuming stage is shorter than the preset time, the control unit can decrease the initial opening of the gas supply regulating valve or limit the frequency increase rate of the primary pump. When the reactor pressure does not reach the target pressure during the pressure holding stage, the control unit can increase the target frequency of the primary pump; when the reactor pressure exceeds the allowable range corresponding to the target pressure, the control unit can decrease the target frequency of the primary pump or correct it through the gas supply regulating valve.

[0122] During the second vacuuming stage, if the actual vacuuming time is longer than the preset time, the control unit can increase the target frequency of the primary pump; if the actual vacuuming time is shorter than the preset time, the control unit can decrease the target frequency of the primary pump. This allows the vacuuming process in the next stage or the next batch to more closely approximate the preset pressure change requirements.

[0123] During the third vacuuming stage, when the pressure in the reactor exceeds the target pressure requirement corresponding to the third vacuuming stage, the control unit can control the vacuum regulating valve to maintain a fixed opening and finely adjust the pressure through the gas replenishment regulating valve or the operating status of the pump group, so that the pressure in the reactor is maintained within the allowable range corresponding to the third vacuuming stage.

[0124] In some examples, the system also supports automatic and manual control modes. In automatic control mode, the control unit automatically controls the vacuum pump unit, vacuum regulating valve, and gas replenishment regulating valve according to the aforementioned stage control parameters to achieve automated control of the vacuuming process. In manual control mode, operators can directly adjust the pump unit frequency, valve opening, and pump start / stop status through the human-machine interface unit to adapt to scenarios such as equipment debugging, process anomaly handling, or maintenance. In some examples, the manually adjusted parameters can also be saved as new recipe parameters for subsequent production use.

[0125] Through the above specific examples, the control unit can sequentially control the pressure changes of the vacuum buffer tank and the reactor according to the first, second, and third vacuuming stages, so that the reactor pressure gradually reaches the target pressure corresponding to each vacuuming stage. Compared with the method of relying on manual experience to adjust the pump frequency and valve opening, this embodiment can improve the stability of the vacuuming process, the accuracy of stage control, and batch consistency.

[0126] In some examples, in order to ensure the stability and control accuracy of multi-stage vacuum control, the control unit can also perform logical verification and self-correction of the stage control parameters to avoid abnormalities in the vacuum process due to unreasonable parameter settings.

[0127] Specifically, the control unit can verify the initial frequency setting of the first-stage variable frequency vacuum pump. The initial frequency setting can be determined based on whether the pressure in the vacuum buffer tank changes according to a preset pressure change curve during the initial stage of vacuuming. When the initial frequency of the first-stage variable frequency vacuum pump is too low, causing the pressure in the vacuum buffer tank to drop too slowly, the control unit can prompt to increase the initial frequency setting, or automatically increase the initial frequency setting within the allowable range. When the initial frequency of the first-stage variable frequency vacuum pump is too high, causing the pressure in the vacuum buffer tank to drop too quickly, the control unit can prompt to decrease the initial frequency setting, or automatically decrease the initial frequency setting within the allowable range.

[0128] In some examples, the control unit can also verify the target frequency setpoint of the first-stage variable frequency vacuum pump. The target frequency setpoint can be determined based on the degree of agreement between the vacuum buffer tank pressure and the theoretical pressure change curve corresponding to the current vacuuming stage, and whether the reactor pressure reaches the corresponding target reactor pressure at the end of the current vacuuming stage. When the reactor pressure does not reach the corresponding target reactor pressure at the end of the current vacuuming stage, the control unit can increase the target frequency setpoint of the first-stage variable frequency vacuum pump within permissible limits; when the reactor pressure exceeds the corresponding target pressure requirement or the pressure drops too rapidly, the control unit can decrease the target frequency setpoint of the first-stage variable frequency vacuum pump within permissible limits.

[0129] In some examples, the control unit can also verify the initial opening of the gas replenishment regulating valve. The initial opening of the gas replenishment regulating valve can be determined based on whether it can quickly enter a stable regulating state during the initial vacuuming process and whether the pressure in the vacuum buffer tank changes smoothly. When the pressure in the vacuum buffer tank drops too quickly during the initial vacuuming process, the control unit can increase the initial opening of the gas replenishment regulating valve to increase the flow rate of the replenishing regulating gas; when the pressure in the vacuum buffer tank drops too slowly during the initial vacuuming process, the control unit can decrease the initial opening of the gas replenishment regulating valve to reduce the flow rate of the replenishing regulating gas.

[0130] In some examples, the control unit can also correct the pressure deviation setpoint. If, at the end of a vacuuming stage, the deviation between the reactor pressure and the theoretical pressure or the target reactor pressure exceeds a preset allowable range, the control unit can correct the pressure deviation setpoint corresponding to that vacuuming stage. For example, if the reactor pressure follows the change in vacuum buffer tank pressure too slowly, the control unit can appropriately increase the pressure deviation setpoint corresponding to that vacuuming stage to increase the rate at which the reactor pressure follows the change in vacuum buffer tank pressure; if the reactor pressure changes too quickly, the control unit can appropriately decrease the pressure deviation setpoint corresponding to that vacuuming stage to reduce the risk of sudden pressure changes in the reactor.

[0131] In some examples, the control unit can also correct abnormal adjustment states of the gas replenishment regulating valve. When the gas replenishment regulating valve closes too quickly, causing the pressure in the vacuum buffer tank or reactor to deviate from the theoretical pressure change curve corresponding to the current vacuuming stage, the control unit can increase the initial frequency setpoint and / or target frequency setpoint of the first-stage variable frequency vacuum pump and control the gas replenishment regulating valve to increase its opening, so that the pressure in the vacuum buffer tank and reactor returns to the pressure change requirements corresponding to the current vacuuming stage.

[0132] Through the above parameter verification and self-correction processing, the control unit can correct the frequency parameters of the first-stage variable frequency vacuum pump, the opening parameters of the gas replenishment regulating valve, and the pressure deviation setting value according to the pressure changes during the actual vacuuming process. This improves the fit between the pressure change curve of the vacuum buffer tank and the preset pressure change curve, and enhances the accuracy and stability of the reactor pressure reaching the stage target pressure.

[0133] In some examples, the control unit can also perform initialization checks and startup sequence control before executing multi-stage vacuum control to improve system operational safety and control stability.

[0134] Specifically, upon receiving the automatic operation command, the control unit first initializes the operating status variables, timing variables, stage identifiers, alarm information, and safety protection flags, and records the current vacuum buffer tank pressure as the stage starting pressure for the current vacuuming stage. The stage starting pressure can be used to subsequently calculate the vacuum buffer tank pressure setpoint for the current vacuuming stage.

[0135] In some examples, the control unit can also perform logical checks on the stage control parameters to prevent unreasonable parameter setting order. For instance, when the target frequency setpoint of the variable frequency vacuum pump is less than the initial frequency setpoint, the control unit can correct the target frequency setpoint to be no less than the initial frequency setpoint; when the target opening setpoint of the gas supply regulating valve is greater than the initial opening setpoint, the control unit can correct the target opening setpoint to be no greater than the initial opening setpoint; when the target frequency setpoint corresponding to the second vacuuming stage is less than the target frequency setpoint corresponding to the first vacuuming stage, the control unit can correct the target frequency setpoint corresponding to the second vacuuming stage to be no less than the target frequency setpoint corresponding to the first vacuuming stage. This avoids abnormal vacuuming control caused by parameter inversion.

[0136] In some examples, the control unit can also calculate the pressure change rate of the vacuum buffer tank. Specifically, the control unit can acquire multiple pressure data points collected by the pressure detection device of the vacuum buffer tank according to a preset sampling period, and determine the pressure change rate of the vacuum buffer tank based on the pressure change within a preset time window. The pressure change rate of the vacuum buffer tank can be used to determine whether the pressure drop rate of the vacuum buffer tank meets the pressure change requirements corresponding to the current vacuuming stage.

[0137] In some examples, the control unit can record the current pressure of the vacuum buffer tank at the stage switching time of each vacuuming stage, as the stage starting pressure of the corresponding vacuuming stage. The stage switching time can include one or more of the following: the start time of the first vacuuming stage, the start time of the pressure holding period of the first vacuuming stage, the start time of the second vacuuming stage, the start time of the pressure holding period of the second vacuuming stage, and the start time of the third vacuuming stage. By recording the stage starting pressure of the vacuum buffer tank at the stage switching time, the control unit can determine the vacuum buffer tank pressure setpoint corresponding to the current moment based on the stage starting pressure, the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, the pressure ramp-up time, and the running time.

[0138] In some examples, the control unit may perform a safety condition check before formally entering vacuum control. When the safety conditions are met, the control unit enters the startup process; when the safety conditions are not met and persist for more than a preset time, the control unit outputs an alarm message to prompt the operator to check the equipment status. Safety conditions may include one or more of the following being in a start-up-allowed state: vacuum pump unit, valves, detection units, interlock signals, or process permission signals.

[0139] In some examples, the control unit initiates the vacuuming process according to a preset startup sequence. Specifically, the control unit may first control the gas supply regulating valve to open and set it to a fixed opening mode, so that the gas supply regulating valve is at its initial opening; after the control unit receives a feedback signal that the gas supply regulating valve is fully open, it then controls the first-stage variable frequency vacuum pump to start and operate it according to the initial frequency setting; after the control unit receives a feedback signal that the first-stage variable frequency vacuum pump is running, it enters the vacuuming control process.

[0140] During startup, if the gas supply regulating valve or the primary variable frequency vacuum pump fails to respond or enter operating mode within a preset time, the control unit can output corresponding fault alarm information and stop or maintain the current startup process. This avoids entering vacuum control when valves are not open, pumps are not running, or abnormal feedback occurs, thus improving system operational safety.

[0141] In some examples, during the vacuum control process, the control unit can also continuously accumulate the program running time and the running time of the current vacuum stage. The running time can be used to determine the vacuum buffer tank pressure setpoint at the current moment, or to determine whether the current vacuum stage has reached the pressure ramp-up time, pressure holding time, or stage switching time.

[0142] Through the above-mentioned initialization verification, parameter error prevention, stage start pressure recording, pressure change rate calculation, and sequential start control, the control unit can establish a stable initial control state before entering multi-stage vacuum control, and accurately identify the stage start point and running time during the vacuum process, thereby improving the reliability of vacuum buffer tank pressure control and reactor pressure follow-up control.

[0143] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0144] Based on the same concept, this application also provides a multi-stage vacuum pumping intelligent control device, which includes: The data acquisition module is used to collect the pressure of the reactor and the vacuum buffer tank in real time. The control module controls the vacuum pump unit to evacuate the vacuum buffer tank according to the stage control parameters corresponding to the current evacuation stage and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current evacuation stage; based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current evacuation stage, it controls the opening of the vacuum regulating valve so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current evacuation stage; after the current evacuation stage is completed, it switches to the next evacuation stage and continues to perform evacuation control according to the stage control parameters corresponding to the next evacuation stage, until the evacuation control corresponding to multiple evacuation stages is completed.

[0145] In some examples, the stage control parameters include pressure ramp-up time; based on the stage control parameters corresponding to the current vacuuming stage and the pressure of the vacuum buffer tank, the vacuum pump unit is controlled to evacuate the vacuum buffer tank, including: determining the vacuum buffer tank pressure setpoint at the current moment based on the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, the pressure ramp-up time, and the running time of the current vacuuming stage; comparing the pressure of the vacuum buffer tank with the vacuum buffer tank pressure setpoint, and adjusting the operating frequency of the vacuum pump unit according to the comparison result, so that the vacuum pump unit evacuates the vacuum buffer tank.

[0146] In some examples, the vacuum pump unit includes a variable frequency vacuum pump; the stage control parameters also include: an initial frequency setpoint and a target frequency setpoint; adjusting the operating frequency of the vacuum pump unit according to the comparison results so that the vacuum pump unit evacuates the vacuum buffer tank, including: determining the basic operating frequency of the variable frequency vacuum pump according to the initial frequency setpoint, target frequency setpoint, pressure ramp-up time, and the running time of the current evacuation stage; dynamically compensating and adjusting the basic operating frequency according to the comparison results to determine the target operating frequency including the variable frequency vacuum pump at the current moment, and controlling the variable frequency vacuum pump to evacuate according to the target operating frequency.

[0147] In some examples, the base operating frequency of the variable frequency vacuum pump is determined based on the initial frequency setpoint, target frequency setpoint, pressure ramp-up time, and the elapsed running time of the current vacuuming phase. This includes inputting the initial frequency setpoint, target frequency setpoint, pressure ramp-up time, and the elapsed running time of the current vacuuming phase into a parabolic model to obtain the base operating frequency. The parabolic model includes: ; in, The running time for the current vacuuming phase is The basic operating frequency of the time-varying frequency vacuum pump Set the initial frequency value. Set a value for the target frequency. For pressure ramp-up time, and and Use the same unit of time.

[0148] In some examples, the multi-stage vacuum intelligent control system also includes a gas replenishment regulating valve connected to the vacuum buffer tank; the device is also used to dynamically adjust the opening of the gas replenishment regulating valve according to the difference between the pressure of the vacuum buffer tank and the set pressure value of the vacuum buffer tank, so as to replenish the vacuum buffer tank with regulating gas.

[0149] In some examples, the opening of the vacuum regulating valve is controlled based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation setpoint corresponding to the current vacuuming stage. This includes: determining the actual pressure difference between the reactor pressure and the vacuum buffer tank pressure; determining the minimum safe pressure difference threshold based on the pressure deviation setpoint corresponding to the current vacuuming stage; when the actual pressure difference is greater than the minimum safe pressure difference threshold, controlling the vacuum regulating valve to remain open or adjust to the set opening to connect the reactor and the vacuum buffer tank; and when the actual pressure difference is less than or equal to the minimum safe pressure difference threshold, controlling the vacuum regulating valve to decrease its opening or close.

[0150] Figure 3 This is a schematic diagram of the electronic device 3 provided in an embodiment of this application. Figure 3 As shown, the electronic device 3 in this embodiment includes a processor 301, a memory 302, and a computer program 303 stored in the memory 302 and executable on the processor 301. When the processor 301 executes the computer program 303, it implements the steps in the various method embodiments described above. Alternatively, when the processor 301 executes the computer program 303, it implements the functions of each module / unit in the various multi-stage vacuum intelligent control device embodiments described above.

[0151] Electronic device 3 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 3 may include, but is not limited to, processor 301 and memory 302. Those skilled in the art will understand that... Figure 3 This is merely an example of electronic device 3 and does not constitute a limitation on electronic device 3. It may include more or fewer components than shown, or different components.

[0152] The processor 301 may 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, discrete gate or transistor logic devices, discrete hardware components, etc.

[0153] The memory 302 can be an internal storage unit of the electronic device 3, such as a hard disk or memory of the electronic device 3. The memory 302 can also be an external storage device of the electronic device 3, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the electronic device 3. The memory 302 can also include both internal and external storage units of the electronic device 3. The memory 302 is used to store computer programs and other programs and data required by the electronic device.

[0154] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the multi-stage vacuum intelligent control device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0155] If integrated modules / units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium may include: any entity or multi-stage vacuum intelligent control device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to regional requirements and patent practice requirements. For example, in some regions, according to regional requirements and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0156] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A multi-stage intelligent vacuum control system, characterized in that, The system includes: a reaction vessel, a vacuum buffer tank, a vacuum pump unit, a vacuum regulating valve, a detection unit, and a control unit; The reactor is connected to the vacuum buffer tank via the vacuum regulating valve, and the vacuum pump unit is connected to the vacuum buffer tank; The detection unit includes a reactor pressure detection device and a vacuum buffer tank pressure detection device. The reactor pressure detection device is used to collect the pressure of the reactor, and the vacuum buffer tank pressure detection device is used to collect the pressure of the vacuum buffer tank. The control unit is connected to the detection unit, the vacuum pump group, and the vacuum regulating valve respectively. The control unit is used to coordinately control the vacuum pump group and the vacuum regulating valve according to the stage control parameters corresponding to the current vacuuming stage, the pressure of the reactor, and the pressure of the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, and the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuuming stage.

2. The system according to claim 1, characterized in that, The system also includes a gas replenishment regulating valve, which is connected to the vacuum buffer tank and the control unit; The gas replenishment regulating valve is used to replenish the vacuum buffer tank with regulating gas under the control of the control unit, so as to regulate the pressure change state of the vacuum buffer tank.

3. The system according to claim 1, characterized in that, The multiple vacuuming stages include at least a first vacuuming stage, a second vacuuming stage, and a third vacuuming stage; The stage control parameters corresponding to each vacuuming stage include the target pressure of the reactor, the target pressure of the vacuum buffer tank, the pressure deviation setting between the vacuum buffer tank and the reactor, the pressure ramp-up time, and the pressure holding time.

4. The system according to claim 1, characterized in that, The vacuum pump assembly includes a variable frequency vacuum pump and at least one fixed frequency vacuum pump. The variable frequency vacuum pump is connected to the control unit via a frequency converter, and the variable frequency vacuum pump is used to perform basic vacuuming of the vacuum buffer tank under the control of the control unit. The at least one fixed-frequency vacuum pump is connected to the vacuum buffer tank and to the control unit, and is used to participate in evacuating the vacuum buffer tank under the control of the control unit.

5. A multi-stage intelligent vacuum control method, characterized in that, The method is applied to the multi-stage vacuum intelligent control system as described in any one of claims 1-4, and the method includes: Real-time monitoring of the pressure in the reactor and the vacuum buffer tank; Based on the stage control parameters corresponding to the current vacuuming stage and the pressure of the vacuum buffer tank, the vacuum pump group is controlled to evacuate the vacuum buffer tank, so that the pressure of the vacuum buffer tank changes according to the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage. Based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation setting value corresponding to the current vacuuming stage, the opening of the vacuum regulating valve is controlled so that the pressure of the reactor follows the pressure change of the vacuum buffer tank to the target pressure of the reactor corresponding to the current vacuuming stage. After the current vacuuming stage is completed, switch to the next vacuuming stage and continue vacuuming control according to the stage control parameters corresponding to the next vacuuming stage until the vacuuming control corresponding to multiple vacuuming stages is completed.

6. The method according to claim 5, characterized in that, The stage control parameters include pressure ramp-up time; based on the stage control parameters corresponding to the current vacuuming stage and the pressure of the vacuum buffer tank, the vacuum pump group is controlled to evacuate the vacuum buffer tank, including: Based on the target pressure of the vacuum buffer tank corresponding to the current vacuuming stage, the pressure ramp-up time, and the running time of the current vacuuming stage, determine the vacuum buffer tank pressure set value at the current moment. The pressure of the vacuum buffer tank is compared with the set pressure value of the vacuum buffer tank, and the operating frequency of the vacuum pump group is adjusted according to the comparison result so that the vacuum pump group evacuates the vacuum buffer tank.

7. The method according to claim 6, characterized in that, The vacuum pump assembly includes a variable frequency vacuum pump; the stage control parameters further include: an initial frequency setpoint and a target frequency setpoint; adjusting the operating frequency of the vacuum pump assembly according to the comparison result, so that the vacuum pump assembly evacuates the vacuum buffer tank, including: The basic operating frequency of the variable frequency vacuum pump is determined based on the initial frequency setting value, the target frequency setting value, the pressure ramp-up time, and the running time of the current vacuuming stage. Based on the comparison results, the basic operating frequency is dynamically compensated and adjusted to determine the target operating frequency of the variable frequency vacuum pump at the current moment, and the variable frequency vacuum pump is controlled to perform vacuuming according to the target operating frequency.

8. The method according to claim 7, characterized in that, Based on the initial frequency setting value, the target frequency setting value, the pressure ramp-up time, and the running time of the current vacuuming stage, the basic operating frequency of the variable frequency vacuum pump is determined, including: The initial frequency setting, the target frequency setting, the pressure ramp-up time, and the running time of the current vacuuming stage are input into the parabolic model to obtain the basic operating frequency. The parabolic model includes: ； in, The running time for the current vacuuming phase is The basic operating frequency of the variable frequency vacuum pump is as described above. Set the initial frequency value. Set a value for the target frequency. The pressure ramp-up time is, and and Use the same unit of time.

9. The method according to claim 6, characterized in that, The multi-stage vacuum intelligent control system further includes a gas replenishment regulating valve, which is connected to the vacuum buffer tank; the method further includes: The opening of the gas replenishment regulating valve is dynamically adjusted based on the difference between the pressure of the vacuum buffer tank and the pressure setting value of the vacuum buffer tank, so as to replenish the vacuum buffer tank with regulating gas.

10. The method according to claim 5, characterized in that, Based on the pressure of the reactor, the pressure of the vacuum buffer tank, and the pressure deviation set value corresponding to the current vacuuming stage, the opening degree of the vacuum regulating valve is controlled, including: Determine the actual pressure difference between the pressure of the reactor and the pressure of the vacuum buffer tank; The minimum safe differential pressure threshold is determined based on the pressure deviation setting value corresponding to the current vacuuming stage. When the actual pressure difference is greater than the minimum safe pressure difference threshold, the vacuum regulating valve is controlled to remain open or adjusted to a set opening degree so that the reactor is connected to the vacuum buffer tank. When the actual pressure difference is less than or equal to the minimum safe pressure difference threshold, the vacuum regulating valve is controlled to reduce its opening or close.

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