Automatic control system and method for chemical process pump

Abstract

The invention relates to the field of automatic control, in particular to an automatic control system and method for a chemical process pump. The system comprises: a gap detection module configured to: collect a first gap G1 between an impeller and a front wear plate; the compression amount detection module is configured to collect the compression amount of the mechanical seal to obtain the seal compression amount C; the PLC is configured to generate a third control instruction based on the first difference value D1 under the condition that the real-time comprehensive quantity Q is larger than a comprehensive quantity threshold value Q1 and the sealing compression amount C is smaller than a first compression amount limiting value C1, and send the third control instruction to the first driving module, so that the first driving module drives a first adjusting jackscrew, and the second driving module drives a second adjusting jackscrew to adjust the sealing compression amount C; and then the axial gap between the front wear-resisting plate and the impeller is reduced by a first difference value D1. According to the system, cooperative precise control over gaps and sealing can be achieved, the operation safety is improved, continuous chemical production can be guaranteed, and shutdown losses are reduced.

Description

Technical Field

[0001] This application relates to the field of automatic control, and more particularly to an automatic control system and method for a chemical process pump. Background Technology

[0002] A chemical process pump is a centrifugal pump specifically designed for chemical production. It is used to continuously and stably transport liquids (acids, alkalis, solvents, slurries, etc.) that are corrosive, toxic, flammable, or at high temperatures and pressures. It is one of the core pieces of equipment in the chemical production process.

[0003] However, during the operation of chemical process pumps, some operational losses occur, such as changes in assembly status. In existing processes, the assembly status is generally checked by shutting down the pump for maintenance, but this shutdown hinders production and reduces efficiency. Summary of the Invention

[0004] This application provides an automatic control system and method for a chemical process pump to solve the problem of difficult maintenance of chemical process pumps.

[0005] In a first aspect, embodiments of this application provide an automatic control system for a chemical process pump, applied to a chemical process pump. The chemical process pump includes at least: a pump body, an impeller, a front wear-resistant plate, a first adjusting screw, and a mechanical seal. The pump body and the impeller are arranged axially opposite each other. The front wear-resistant plate is located inside the pump body and is arranged axially opposite to the impeller. The first adjusting screw passes through the pump body axially and abuts against the front wear-resistant plate, used to drive the front wear-resistant plate to move relative to the impeller, thereby reducing the axial gap between the front wear-resistant plate and the impeller. The mechanical seal includes an elastic element, used to provide axial sealing to the chemical process pump through axial elastic deformation. The system includes: a gap detection module configured to: in response to a first control command, acquire a first gap G1 between the impeller and the front wear-resistant plate; a compression detection module configured to: in response to a second control command, acquire the compression of the mechanical seal to obtain a sealing compression C; the sealing compression C is proportional to the compression degree of the elastic element of the mechanical seal; and a programmable logic controller (PLC) configured to: operate at a first preset frequency. Based on the most recently acquired first gap G1 and the most recently acquired sealing compression C, a real-time comprehensive quantity Q is generated; and, according to a first preset frequency, a first difference D1 between the first gap G1 and the standard gap G is calculated; when the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression C is less than the first compression limit C1, a third control command is generated based on the first difference D1, and the third control command is sent to the first drive module to drive the first adjusting screw, thereby reducing the axial gap between the front wear-resistant plate and the impeller by the first difference D1; and the PLC is also configured to: input the first gap G1 and sealing compression C acquired N times before the current moment into the first prediction model according to a second preset frequency, and use the first prediction model to predict the first adjustment time and the second adjustment time; the first adjustment time and the second adjustment time may be the same or different; when the first adjustment time arrives, a new first control command is generated; when the second adjustment time arrives, a new second control command is generated.

[0006] In one possible implementation, the chemical process pump further includes a first bearing, a rear bearing cover, and a second adjusting screw. The first bearing is axially connected to the impeller, the rear bearing cover is located on the side of the first bearing away from the impeller, and the second adjusting screw passes axially through the rear bearing cover and abuts against the first bearing. The second adjusting screw is used to drive the first bearing and the impeller to move towards the pump body to reduce the axial clearance between the front wear plate and the impeller. The PLC is also configured to generate a fourth control command based on a first preset value when the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1, and the sealing compression quantity C is greater than or equal to the first compression quantity limit C1 and less than the second compression quantity limit C2, and send the fourth control command to the second drive module so that the second drive module drives the second adjusting screw, thereby reducing the axial clearance between the front wear plate and the impeller by the first preset value.

[0007] In one possible implementation, the PLC is further configured to: generate a fifth control instruction based on a second preset value when the sealing compression amount C is greater than or equal to the second compression limit C2, and send the fifth control instruction to the second drive module so that the second drive module drives the second adjusting screw, thereby reducing the axial clearance between the front wear plate and the impeller by a second preset value; wherein the second preset value is greater than the first preset value.

[0008] In one possible implementation, the PLC is further configured to: collect real-time operating conditions of the chemical process pump at a second preset frequency, the real-time operating conditions including real-time speed, pump outlet pressure, conveyed medium temperature, motor output power and / or bearing temperature; determine multiple historical curves matching the real-time operating conditions; generate a first gap curve based on the first gap G1 collected N times prior to the current moment, and generate a second gap curve based on all first gaps G1, the first gap curve and the second gap curve being curves of the first gap G1 changing over time; and the PLC is further configured to: generate a first sealing compression curve based on the sealing compression amount C collected N times prior to the current moment, and generate a second sealing compression curve based on all sealing compression amounts C, the first sealing compression curve and the second sealing compression curve being curves of the sealing compression amount C changing over time; input the multiple historical curves, the first gap curve, the second gap curve, the first sealing compression curve and the second sealing compression curve into a first prediction model to determine a first adjustment time and a second adjustment time.

[0009] In one possible implementation, the multiple historical curves include multiple historical gap curves and multiple historical compression curves; the PLC is further configured to: determine a historical gap curve matching the second gap curve based on a first prediction model; determine a first curve segment in the matched historical gap curve; wherein the trend similarity between the first curve segment and the first gap curve is greater than a similarity threshold; determine a first target point located in the first curve segment in the historical gap curve along the time direction, wherein the ordinate corresponding to the first target point corresponds to the most recently acquired first gap G1; determine a first adjustment time based on the abscissa corresponding to the first target point; and the PLC is further configured to: determine a historical compression curve matching the second sealing compression curve based on the first prediction model; determine a second curve segment in the matched historical compression curve; wherein the trend similarity between the second curve segment and the first sealing compression curve is greater than a similarity threshold; determine a second target point located in the second curve segment in the historical compression curve along the time direction, wherein the ordinate corresponding to the second target point corresponds to the most recently acquired sealing compression C; and determine a second adjustment time based on the abscissa corresponding to the second target point.

[0010] In one possible implementation, the PLC is further configured to: collect the second adjustment time determined M times before the current time according to a third preset frequency; wherein the value of M is preset; input the second adjustment time determined M times before the current time into the second prediction model, and use the second prediction model to predict the aging time of the mechanical seal; generate the first alarm information at the target time point, the target time point being before the aging time and having a preset time interval between it and the aging time.

[0011] In one possible implementation, the PLC is further configured to: generate a first alarm message when the first adjustment time or the second adjustment time is less than a first time threshold; and / or generate a second alarm message when the time difference between two adjacent first adjustment times is less than a second time threshold; and / or generate a third alarm message when the time difference between two adjacent second adjustment times is less than a third time threshold.

[0012] In one possible implementation, the PLC is also configured to generate a fourth alarm message if the first difference D1 is greater than the difference threshold.

[0013] Secondly, embodiments of this application provide an automatic control method for a chemical process pump, applied to a chemical process pump. The chemical process pump includes at least: a pump body, an impeller, a front wear-resistant plate, a first adjusting screw, and a mechanical seal. The pump body and the impeller are arranged axially opposite each other. The front wear-resistant plate is located inside the pump body and is arranged axially opposite to the impeller. The first adjusting screw passes through the pump body axially and abuts against the front wear-resistant plate, used to drive the front wear-resistant plate to move relative to the impeller, thereby reducing the axial clearance between the front wear-resistant plate and the impeller. The mechanical seal includes an elastic element, used to provide axial sealing to the chemical process pump through axial elastic deformation. The method includes: in response to a first control command, acquiring a first clearance G1 between the impeller and the front wear-resistant plate; in response to a second control command, acquiring the compression amount of the mechanical seal to obtain a sealing compression amount C; the sealing compression amount is proportional to the compression degree of the elastic element of the mechanical seal; according to a first preset frequency, based on the most recently acquired first clearance G1 and the most recently acquired sealing compression amount C, The method generates a real-time comprehensive quantity Q; and calculates a first difference D1 between a first gap G1 and a standard gap G according to a first preset frequency; when the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression quantity C is less than the first compression quantity limit C1, a third control command is generated based on the first difference D1 and sent to the first drive module so that the first drive module drives the first adjusting screw, thereby reducing the axial gap between the front wear-resistant plate and the impeller by the first difference D1; and the method further includes: inputting the first gap G1 and the sealing compression quantity C collected N times before the current moment into a first prediction model according to a second preset frequency, and using the first prediction model to predict a first adjustment time and a second adjustment time; the first adjustment time and the second adjustment time may be the same or different; when the first adjustment time arrives, a new first control command is generated and sent to the gap detection module; when the second adjustment time arrives, a new second control command is generated and sent to the compression quantity detection module.

[0014] Thirdly, embodiments of this application also provide an electronic device, including: one or more processors; and a memory configured to store one or more programs; wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the automatic control method for a chemical process pump according to the second aspect.

[0015] As can be seen from the above, this application provides an automatic control system for a chemical process pump, applied to a chemical process pump. The chemical process pump includes at least: a pump body, an impeller, a front wear-resistant plate, a first adjusting screw, and a mechanical seal. The pump body and the impeller are arranged axially opposite each other. The front wear-resistant plate is located inside the pump body and is arranged axially opposite to the impeller. The first adjusting screw passes through the pump body axially and abuts against the front wear-resistant plate, used to drive the front wear-resistant plate to move relative to the impeller, thereby reducing the axial gap between the front wear-resistant plate and the impeller. The mechanical seal includes an elastic element, used to provide axial sealing to the chemical process pump through axial elastic deformation. The system includes: a gap detection module, configured to: in response to a first control command, acquire a first gap G1 between the impeller and the front wear-resistant plate; a compression detection module, configured to: in response to a second control command, acquire the compression of the mechanical seal to obtain a sealing compression C; the sealing compression is proportional to the compression degree of the elastic element of the mechanical seal; and a programmable logic controller (PLC), configured to: according to a first preset frequency, based on the most recently acquired data... The system generates a real-time comprehensive quantity Q based on the first gap G1 and the most recently acquired sealing compression quantity C; and calculates a first difference D1 between the first gap G1 and the standard gap G according to a first preset frequency; if the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression quantity C is less than the first compression quantity limit C1, a third control command is generated based on the first difference D1 and sent to the first drive module to drive the first adjusting screw, thereby reducing the axial gap between the front wear-resistant plate and the impeller by the first difference D1; and the PLC is also configured to: input the first gap G1 and sealing compression quantity C acquired N times before the current moment into the first prediction model according to a second preset frequency, and use the first prediction model to predict the first adjustment time and the second adjustment time; the first adjustment time and the second adjustment time may be the same or different; when the first adjustment time arrives, a new first control command is generated and sent to the gap detection module; when the second adjustment time arrives, a new second control command is generated and sent to the compression quantity detection module. This system can achieve precise control of "gap-seal" coordination, predict the detection time in advance through predictive models to reduce human error; in addition, it can provide early warning of seal leakage, improve operational safety, and ensure continuous chemical production, reducing downtime losses. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a first structure of a chemical process pump provided in an embodiment of this application; Figure 2 This is a schematic diagram of a second structure of a chemical process pump provided in an embodiment of this application; Figure 3 A schematic diagram of the structure of an automatic control system for a chemical process pump provided in an embodiment of this application; Figure 4A schematic flowchart of an automatic control method for a chemical process pump provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0017] The components include: processor-10; memory-20; pump body-1001; impeller-1002; front wear-resistant plate-1003; first adjusting screw-1004; mechanical seal-1005; first bearing-1006; rear bearing cover-1007; second adjusting screw-1008; shaft-1009; bearing suspension-1010; sealing ring-1011; plug-in-1012; pump support foot-1013; impeller nut-1014; front bearing cover-1015; and front baffle plate-1016. Impeller key - 1017; Eye bolt - 1018; Vent plug - 1019; Pump cover gasket - 1020; Coupling key - 1021; Round nut - 1022; Rear baffle plate - 1023; Impeller inlet ring - 1024; Pump body inlet ring - 1025; Pump cover - 1026; Second bearing - 1027; Gap detection module - 2001; Compression detection module - 2002; Programmable Logic Controller (PLC) - 2003; First drive module - 2004; Second drive module - 2005. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0019] To address the challenge of inspecting chemical process pumps, this application provides an automatic control system and method for chemical process pumps. This method can dynamically adjust the clearance and sealing status by real-time acquisition of key parameters of the chemical process pump (axial clearance between the front wear plate and the impeller, and the sealing compression of the mechanical seal) combined with intelligent analysis and prediction by a programmable logic controller (PLC). This allows for assembly status monitoring and fault warning without shutdown, fundamentally avoiding the impact of traditional shutdown maintenance on production continuity while ensuring pump operating efficiency and sealing reliability.

[0020] Figure 1 This is a schematic diagram of a first structure of a chemical process pump provided in an embodiment of this application.

[0021] like Figure 1As shown, the chemical process pump provided in this application embodiment may include a pump body 1001, an impeller 1002, a front wear-resistant plate 1003, a first adjusting screw 1004, and a mechanical seal 1005. The pump body 1001 and the impeller 1002 are arranged opposite each other along the axial direction. The impeller 1002 may be a semi-open impeller. The front wear-resistant plate 1003 is located inside the pump body 1001 and is arranged opposite to the impeller 1002 along the axial direction. The first adjusting screw 1004 passes through the pump body 1001 along the axial direction and abuts against the front wear-resistant plate 1003, and is used to drive the front wear-resistant plate 1003 to move relative to the impeller 1002, so as to reduce the axial gap between the front wear-resistant plate 1003 and the impeller 1002. The mechanical seal 1005 may include an elastic element, which is used to provide axial sealing for the chemical process pump through axial elastic deformation.

[0022] It should be further explained that axial sealing is a concept relative to radial sealing. Axial sealing is a sealing method that prevents the medium from leaking along the axial gap of the shaft by the sealing element fitting or blocking it in a direction parallel to the axis of rotation. Radial sealing is a sealing method that prevents the medium from leaking along the radial fit gap between the shaft and the housing by the sealing element compressing or fitting it in a radial direction perpendicular to the axis of rotation.

[0023] Figure 2 This is a schematic diagram of a second structure of a chemical process pump provided in an embodiment of this application.

[0024] like Figure 2 As shown, the chemical process pump may further include a first bearing 1006, a rear bearing cover 1007, and a second adjusting screw 1008. The first bearing 1006 is axially connected to the impeller 1002. The rear bearing cover 1007 is located on the side of the first bearing 1006 away from the impeller 1002. The second adjusting screw 1008 passes axially through the rear bearing cover 1007 and abuts against the first bearing 1006. The second adjusting screw 1008 is used to drive the first bearing 1006 and the impeller 1002 to move toward the pump body 1001 to reduce the axial clearance between the front wear plate 1003 and the impeller 1002.

[0025] It is understood that the above content is only a partial structural introduction of the chemical process pump. In order to achieve normal operation of the pump, the chemical process pump also includes other structures, such as shaft 1009, bearing suspension 1010, sealing ring 1011, plug 1012, pump support 1013, impeller nut 1014, front bearing cover 1015, front baffle 1016, impeller key 1017, eye bolt 1018, vent plug 1019, pump cover gasket 1020, coupling key 1021, round nut 1022, rear baffle 1023, impeller inlet ring 1024, pump body inlet ring 1025, pump cover 1026, second bearing 1027, etc., and also includes a motor. For example, the sealing ring 1011 can be fitted at the stationary joint of a chemical process pump. The stationary joint, also known as the low-pressure static seal, is not in direct contact with the high pressure of the medium. In layman's terms, the stationary joint is the seam that needs to be sealed when two "non-rotating parts" in the pump are close together. The sealing ring 1011 can be an O-ring, specifically it can be set at the stationary threaded or flange mating surface of the stationary ring seat of the mechanical seal 1005 and the pump cover 1026, the cooling water / flushing fluid interface, the pressure gauge / temperature gauge connector, etc., to provide radial and / or axial sealing. This application embodiment does not specifically limit this.

[0026] It should be further explained that the working principle of mechanical seal 1005 is based on the axial contact design of the sealing surfaces, specifically as follows: Mechanical seal 1005 includes a rotating ring (rotating synchronously with shaft 1009 and fixed relative to shaft 1009) and a stationary ring (not rotating with shaft 1009). The sealing end faces of the two are axially opposite each other (the end faces are perpendicular to the axis of shaft 1009). During normal operation, the end faces of the rotating and stationary rings are tightly fitted under the axial elastic force of elastic elements (such as springs or bellows), forming an extremely narrow "sealing end face contact band" to provide axial sealing. The greater the compression of the elastic element, the greater the contact pressure between the rotating and stationary rings, and the more reliable the sealing performance. It should be noted that excessive contact pressure can also lead to seal failure; therefore, the compression should be kept within a certain range.

[0027] Figure 3 A schematic diagram of the structure of an automatic control system for a chemical process pump provided in an embodiment of this application.

[0028] like Figure 3As shown in the embodiments of this application, the automatic control system for a chemical process pump may include a gap detection module 2001, a compression detection module 2002, a programmable logic controller (PLC) 2003, a first drive module 2004, and a second drive module 2005. The gap detection module 2001 can be based on a non-contact displacement detection device, with its detection probe aligned with the axial gap between the front wear-resistant plate 1003 and the impeller 1002. Responding to a first control command, it accurately acquires the gap between the impeller 1002 and the front wear-resistant plate 1003. The compression detection module 2002 can employ a miniature pressure sensor array, with its sensor probe embedded in the elastic element of the mechanical seal 1005 (e.g., a spring seat or the tail end of a bellows). Responding to a second control command, it acquires the feedback pressure generated by the compression of the elastic element through the pressure sensor array, and calculates the sealing compression of the mechanical seal 1005. The conversion formula is as follows: C = P × S / K; Where C represents the sealing compression amount; P represents the feedback pressure; S represents the force-bearing area of ​​the elastic element; and K represents the stiffness parameter of the elastic element.

[0029] In some implementations, the sealing compression C = original free height of the sealing elastic element - actual height after compression. When the sealing elastic element is compressed, the linear dimension decreases (e.g., from 2.0 mm to 1.5 mm), and the value of C (difference) increases simultaneously, intuitively reflecting the direct proportional relationship between the degree of compression and the sealing compression.

[0030] The Programmable Logic Controller (PLC) 2003 serves as the core control unit of the system. It can integrate a data storage module, a model calculation module, and an instruction generation module. The data storage module stores historical gap data, seal compression data, and real-time operating parameters (speed, pressure, etc.). The model calculation module is equipped with a first prediction model (which can be a curve matching model based on a dynamic time warping algorithm) and a second prediction model (which can be an aging prediction model based on linear regression), which can perform adjustment time prediction and mechanical seal 1005 aging time calculation. The instruction generation module generates first control instructions, second control instructions, and third control instructions based on the detection data and model calculation results, thereby realizing coordinated control of various modules.

[0031] The first drive module 2004 is connected to the first adjusting set screw 1004 and consists of a stepper motor, a reduction gear set, and a torque sensor. After receiving the third control command issued by the PLC 2003, the stepper motor adjusts the rotation angle according to the first difference D1 in the command, and transmits the power to the first adjusting set screw 1004 through the reduction gear set, pushing the front wear-resistant plate 1003 to move towards the impeller 1002. The torque sensor monitors the load torque of the adjusting set screw in real time. When the torque exceeds the preset threshold (e.g., 50 N·m), it immediately sends a signal to the PLC 2003 to trigger the adjustment action to pause, avoiding over-adjustment that could cause the component to jam.

[0032] The second drive module 2005 is connected to the second adjusting screw 1008 and has the same structure as the first drive module 2004. It can respond to the fourth control command issued by the PLC 2003 and drive the second adjusting screw 1008 to push the first bearing 1006 and impeller 1002 to move towards the pump body 1001 to meet the gap adjustment requirements.

[0033] Furthermore, the gap detection module 2001 can be configured to perform the following steps S100.

[0034] S100: In response to the first control command, the first gap G1 between the impeller 1002 and the front wear-resistant plate 1003 is collected.

[0035] The PLC 2003 can communicate with the gap detection module 2001, and the first control command can be issued by the PLC 2003. Furthermore, the gap detection module 2001 can transmit the acquired first gap G1 back to the PLC 2003.

[0036] Compression detection module 2002 is configured to perform the following steps S200.

[0037] S200: In response to the second control command, the compression amount of the mechanical seal 1005 is collected to obtain the sealing compression amount C; the sealing compression amount is proportional to the degree of compression of the elastic element of the mechanical seal 1005.

[0038] The PLC 2003 can communicate with the compression detection module 2002, and the second control command can be issued by the PLC 2003. Furthermore, the compression detection module 2002 can transmit the collected compression amount, i.e., the sealing compression amount C, back to the PLC 2003.

[0039] Furthermore, the direct proportionality between the sealing compression C and the degree of compression of the mechanical seal 1005 means that when the axial or radial pressure on the mechanical seal 1005 increases, its physical deformation (i.e., degree of compression) increases, and the tightness of the fit between the mechanical seal 1005 and the mating surface is enhanced. In this case, the sealing compression C value collected by the compression detection module 2002 will increase. Conversely, when the degree of compression of the mechanical seal 1005 decreases, it indicates a decrease in the degree of compression, and the detected sealing compression C value will decrease. This proportional relationship provides an intuitive quantitative basis for the PLC 2003 to judge the sealing status. For example, a newly installed mechanical seal 1005 has a high degree of compression, and C may be 0.2mm (a large value), indicating a good seal. However, after a period of use, if the sealing compression C decreases to 0.05-0.1mm (a small value), it indicates a decrease in the degree of sealing compression; or if it increases to 0.25mm, it indicates an improvement in the sealing compression state of the mechanical seal 1005. This may be due to the component mating process.

[0040] It should also be noted that when the sealing compression C is too large, it means that the mechanical seal 1005 is over-compressed, which may cause plastic deformation, extrusion, or accelerated aging of the mechanical seal 1005, thereby damaging the sealing effect and causing leakage. When the sealing compression C is too small, it means that the mechanical seal 1005 is under-compressed and the compression is insufficient, failing to generate enough contact stress to effectively fill the mating gap, which will also lead to leakage. It can be seen that the sealing compression C has a normal working range. When the real-time value of the sealing compression C is not within this normal working range, it indicates that the sealing state is abnormal, that is, there is an abnormality in the assembly state between the components. In this embodiment, the normal working range may refer to the sealing compression C being less than the first compression limit C1 and greater than or equal to the third compression limit C3. The specific values ​​of the first compression limit C1 and the third compression limit C3 can be determined based on the actual situation. The first compression limit C1 is greater than the third compression limit C3, and this embodiment does not specifically limit this.

[0041] The programmable logic controller (PLC) 2003 can be configured to perform the following steps S301-S302.

[0042] S301: Based on the most recently acquired first gap G1 and the most recently acquired sealing compression C, generate a real-time comprehensive quantity Q according to the first preset frequency, and calculate the first difference D1 between the first gap G1 and the standard gap G according to the first preset frequency.

[0043] It is understandable that the calculation steps of the real-time comprehensive quantity Q and the first difference D1 can be synchronized, that is, the calculation cycles of the two are aligned.

[0044] The formula for calculating the real-time comprehensive quantity Q can be: Q=a×(G1 / G)+b×|C2-C| / (C2-C1); Where Q represents the real-time comprehensive quantity, G1 represents the first clearance, and G represents the standard clearance; C1 represents the first compression limit, C2 represents the second compression limit, and C represents the sealing compression. a and b are weighting coefficients, and a+b=1, a>b. For example, if a is 0.6 and b is 0.4, the impact of clearance on pump efficiency is given priority.

[0045] It is understandable that the second compression limit C2 is greater than the first compression limit C1.

[0046] This formula can quantify and integrate the sealing status of the first gap G1 and the sealing compression C. The larger the Q value, the more significant the combined problem of "gap abnormality + sealing abnormality" of the pump body 1001, providing a quantitative basis for subsequent adjustment.

[0047] Furthermore, the first difference D1 = first gap G1 - standard gap G. The standard gap G can refer to the gap between the impeller 1002 and the front wear-resistant plate 1003 when they are in a standard assembly state. As the chemical process pump operates, the gap between the impeller 1002 and the front wear-resistant plate 1003 gradually increases; therefore, the first difference D1 can be a positive value.

[0048] It should also be noted that the first preset frequency can be 5 minutes / time or 10 minutes / time, and this application embodiment does not specifically limit it.

[0049] S302: When the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression quantity C is less than the first compression quantity limit C1, a third control command is generated based on the first difference D1 and sent to the first drive module 2004 so that the first drive module 2004 drives the first adjusting screw 1004, thereby reducing the axial clearance between the front wear-resistant plate 1003 and the impeller 1002 by the first difference D1.

[0050] If the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1, and the sealing compression quantity C is less than the first compression quantity limit C1, it indicates that there is a significant problem with the assembly state between the front wear-resistant plate 1003 and the impeller 1002, but the compression state of the mechanical seal 1005 is not exceeding the normal state. Therefore, the front wear-resistant plate 1003 can be moved relative to the impeller 1002 by the first adjusting set screw 1004. At this time, the front wear-resistant plate 1003 can move towards the impeller 1002 to reduce the axial clearance between the front wear-resistant plate 1003 and the impeller 1002. This can improve the assembly state between the front wear-resistant plate 1003 and the impeller 1002, increase pump efficiency and motor output power, and avoid energy waste. It is understood that since the sealing compression quantity C has not exceeded the limit, the clearance can be restored simply by moving the front wear-resistant plate 1003, without the need to adjust the seal.

[0051] Furthermore, PLC 2003 can also be configured to perform the following steps S303-S305.

[0052] S303: According to the second preset frequency, the first gap G1 and sealing compression C collected N times before the current time are input into the first prediction model, and the first prediction model is used to predict the first adjustment time and the second adjustment time; the first adjustment time and the second adjustment time may be the same or different.

[0053] The second preset frequency can be 5 min / time or 10 min / time, and N is, for example, equal to 10. This application embodiment does not specifically limit this.

[0054] Furthermore, the first prediction model can be a dynamic prediction model. The specific prediction steps will be detailed below and will not be repeated here.

[0055] It is worth noting that the first adjustment time and the second adjustment time are calculated independently, and are predicted separately based on the changing trends of their respective parameters (such as the clearance wear rate and the seal aging rate). For example, if the clearance wear rate is faster than the seal aging rate, the first adjustment time may be earlier than the second adjustment time, and vice versa.

[0056] S304: When the first adjustment time arrives, a new first control command is generated and sent to the gap detection module 2001.

[0057] This triggers a new round of gap detection. If the first adjustment time is not equal to the second adjustment time, the compression detection module 2002 can be in a sleep state at this time. That is, the workflows of the gap detection module 2001 and the compression detection module 2002 can be asynchronous.

[0058] S305: When the second adjustment time arrives, a new second control command is generated and sent to the compression detection module 2002.

[0059] This can trigger a new round of compression detection. If the second adjustment time is not equal to the first adjustment time, then the gap detection module 2001 can be in a sleep state at this time.

[0060] As can be seen from the above, the embodiments of this application provide an automatic control system for a chemical process pump. The chemical process pump includes at least: a pump body 1001, an impeller 1002, a front wear-resistant plate 1003, a first adjusting screw 1004, and a mechanical seal 1005. The pump body 1001 and the impeller 1002 are axially connected. The front wear-resistant plate 1003 is located inside the pump body 1001 and is axially opposite to the impeller 1002. The first adjusting screw 1004 passes axially through the pump body 1001 and abuts against the front wear-resistant plate 1003, for driving the front wear-resistant plate 1003 to move relative to the impeller 1002, thereby reducing the wear of the front wear-resistant plate 1005. The axial clearance between impeller 1003 and impeller 1002; the mechanical seal 1005 includes an elastic element for providing axial sealing to the chemical process pump through axial elastic deformation; the system includes: a clearance detection module 2001 configured to: in response to a first control command, acquire a first clearance G1 between impeller 1002 and front wear plate 1003; a compression detection module 2002 configured to: in response to a second control command, acquire the compression of mechanical seal 1005 to obtain a sealing compression C; the sealing compression is proportional to the degree of compression of the elastic element of mechanical seal 1005; a programmable logic controller (PLC). 2003 is configured to: generate a real-time comprehensive quantity Q based on the most recently acquired first gap G1 and the most recently acquired sealing compression quantity C according to a first preset frequency; and calculate a first difference D1 between the first gap G1 and the standard gap G according to the first preset frequency; if the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression quantity C is less than the first compression quantity limit C1, generate a third control command based on the first difference D1 and send the third control command to the first drive module 2004, so that the first drive module 2004 drives the first adjusting screw 1004, thereby reducing the axial gap between the front wear-resistant plate 1003 and the impeller 1002 by the first difference D1; and, PLC 2003 is also configured to: input the first gap G1 and sealing compression C collected N times prior to the current moment into the first prediction model according to the second preset frequency; use the first prediction model to predict the first adjustment time and the second adjustment time; the first adjustment time may be the same as or different from the second adjustment time; when the first adjustment time arrives, generate a new first control command and send it to the gap detection module 2001; when the second adjustment time arrives, generate a new second control command and send it to the compression detection module 2002. This system can achieve precise control of "gap-seal" coordination, predict the detection timing in advance through the prediction model, reduce human error; furthermore, it can provide early warning of seal leakage, improve operational safety, and ensure continuous chemical production, reducing downtime losses.

[0061] Furthermore, the PLC 2003 can also be configured to perform the following steps S306: S306: When the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1, and the sealing compression quantity C is greater than or equal to the first compression quantity limit C1 and less than the second compression quantity limit C2, a fourth control command is generated based on the first preset value, and the fourth control command is sent to the second drive module 2005 so that the second drive module 2005 drives the second adjusting screw 1008, thereby reducing the axial clearance between the front wear plate 1003 and the impeller 1002 by the first preset value.

[0062] If the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1, and the sealing compression quantity C is greater than or equal to the first compression quantity limit C1 and the sealing compression quantity C is less than the second compression quantity limit C2, it can indicate that there is a problem with the assembly state between the front wear-resistant plate 1003 and the impeller 1002, and the compression state of the mechanical seal 1005 is also problematic. In this embodiment, the rotor parts such as the first bearing 1006 and the impeller 1002 can be driven to move towards the pump body 1001 by the second adjusting screw 1008, so as to reduce the axial clearance between the front wear-resistant plate 1003 and the impeller 1002 by a first preset value.

[0063] It is worth noting that when the rotor moves towards the pump body 1001 end, the moving ring of the mechanical seal 1005 moves forward with the rotor and pushes the stationary ring in the opposite direction, resulting in a decrease in the compression of the elastic element (spring extension or bellows relaxation). There can be a quantitative linkage between the two: for every decrease of G in the axial clearance, the seal compression C decreases by r×G (where r is a proportionality coefficient determined by the structural parameters of the mechanical seal 1005, such as the stiffness of the elastic element and the axial distance between the moving and stationary rings).

[0064] The decrease in seal compression C can be reflected by detecting the deformation state of the elastic element in the mechanical seal 1005 (such as the change in spring length and the expansion and contraction of the bellows), or by directly measuring the change in the contact pressure between the rotating ring and the stationary ring. Therefore, when the seal compression C is too large, the compression state can be improved by adjusting the relationship between the rotor and the pump body 1001.

[0065] For example, the first preset value can be equal to 0.1mm or 0.2mm, and this application embodiment does not specifically limit it.

[0066] Furthermore, the PLC 2003 can also be configured to perform the following steps S308.

[0067] S308: When the sealing compression amount C is greater than or equal to the second compression limit C2, a fifth control command is generated based on the second preset value, and the fifth control command is sent to the second drive module 2005 so that the second drive module 2005 drives the second adjusting screw 1008, thereby reducing the axial clearance between the front wear plate 1003 and the impeller 1002 by the second preset value; wherein, the second preset value is greater than the first preset value.

[0068] If the sealing compression amount C is greater than or equal to the second compression limit C2, it indicates a serious problem with the compression state of the mechanical seal 1005. Regardless of whether there is a problem with the assembly state between the front wear-resistant plate 1003 and the impeller 1002, adjustment is required. Therefore, in this embodiment, when the sealing compression amount C is greater than or equal to the second compression limit C2, the second adjusting screw 1008 can be driven to reduce the axial clearance between the front wear-resistant plate 1003 and the impeller 1002 by a second preset value.

[0069] The second preset value should be greater than the first preset value to quickly improve the compression state of the mechanical seal 1005. For example, the second preset value can be equal to 0.3 mm, but this application embodiment does not specifically limit it.

[0070] It should be further explained that when the sealing compression C ∈ [C1, C2), the sealing compression C is reduced to [C3, C1) (normal range) by reducing the axial clearance of the first preset value, so as to avoid excessive sealing compression and accelerated wear; when the sealing compression C ≥ C2, the axial clearance is adjusted by a larger second preset value to quickly reduce the sealing compression C to a safe range and prevent the elastic element from failing due to overpressure.

[0071] It is worth noting that driving the first adjusting screw 1004 reduces the axial clearance between the front wear-resistant plate 1003 and the impeller 1002. This adjustment method hardly changes the sealing compression C, so it is suitable for situations where the sealing compression C is within the normal range. Correspondingly, driving the second adjusting screw 1008 reduces the axial clearance between the front wear-resistant plate 1003 and the impeller 1002. This adjustment method drives the first bearing 1006 and the impeller 1002 to move towards the pump body 1001, causing the moving ring of the mechanical seal 1005 to move axially synchronously, thereby changing the compression degree of the elastic element and reducing the sealing compression C. Therefore, it is suitable for situations where the sealing compression C exceeds the normal range (i.e., C≥C1). The sealing compression C can be synchronously corrected by adjusting the axial clearance, ensuring that the sealing state and the clearance state are in a reasonable range.

[0072] Furthermore, the PLC 2003 can also be configured to perform the following steps S3031-S3035.

[0073] S3031: Collect the real-time operating conditions of the chemical process pump according to the second preset frequency. The real-time operating conditions include real-time speed, pump outlet pressure, temperature of the conveyed medium, motor output power and / or bearing temperature.

[0074] The real-time rotational speed can be the real-time rotational speed fed back from the chemical process pump. The pump outlet pressure can be measured by the pressure sensor at the outlet of pump body 1001. The input medium temperature can be measured by the medium temperature sensor. The motor output power can be determined by the power analyzer of the chemical process pump motor. The bearing temperature can be measured by the temperature sensor of the first bearing 1006.

[0075] S3032: Determine multiple historical curves that match real-time operating conditions.

[0076] In this embodiment, a vector corresponding to the real-time operating condition can be constructed. Then, the Euclidean distance between the real-time operating condition vector and each historical operating condition vector in the historical operating condition database is calculated. The curves corresponding to historical operating condition vectors whose Euclidean distance is less than a distance threshold are determined as historical curves matching the real-time operating condition. It is understood that there can be multiple historical curves, including multiple historical gap curves and multiple historical compression curves.

[0077] S3033: Generate a first gap curve based on the first gap G1 collected N times before the current time, and generate a second gap curve based on all first gaps G1.

[0078] The first gap curve and the second gap curve are curves showing the change of the first gap G1 over time. Time can be used as the horizontal axis, and the first gap G1 can be used as the vertical axis.

[0079] It is understandable that all first gaps G1 include the first gap G1 of each acquisition.

[0080] S3034: Generate a first sealing compression curve based on the sealing compression C collected N times prior to the current moment, and generate a second sealing compression curve based on all sealing compression C values.

[0081] The sealing compression curve is a curve showing how the sealing compression C changes over time. Time can be represented on the horizontal axis, and the sealing compression C can be represented on the vertical axis.

[0082] It is understandable that all sealing compression C includes the sealing compression C collected each time.

[0083] S3035: Input multiple historical curves, the first gap curve, the second gap curve, the first seal compression curve, and the second seal compression curve into the first prediction model to determine the first adjustment time and the second adjustment time.

[0084] Furthermore, the PLC 2003 can also be configured to perform the following steps S30351-S30354.

[0085] S30351: Determine the historical gap curve that matches the second gap curve based on the first prediction model.

[0086] Specifically, the first prediction model can be a hybrid model that integrates feature engineering and machine learning. Its core function is to achieve curve matching through multi-dimensional feature comparison, and finally determine the unique historical gap curve that best matches the second gap curve among multiple historical gap curves, thus achieving secondary screening.

[0087] S30352: Determine the first curve segment from the matched historical gap curves; wherein the trend similarity between the first curve segment and the first gap curve is greater than the similarity threshold.

[0088] In this embodiment, the historical gap curve matching the second gap curve is divided into multiple continuous curve segments according to a time window. It is worth noting that the length of the time window is equal to the period corresponding to the second preset frequency × N. For example, when the second preset frequency is 5 minutes / time and N equals 10, the time window can be equal to 50 minutes.

[0089] Subsequently, embodiments of this application can calculate the trend similarity between the first gap curve and each curve segment. Specifically, embodiments of this application can employ algorithms such as Dynamic Time Warping (DTW), correlation coefficient, or least squares method to calculate the similarity between the first gap curve and each curve segment, thereby obtaining the trend similarity between the first gap curve and each curve segment. Further, curve segments with trend similarity greater than a similarity threshold are taken as the first curve segment. It should be noted that when there are not unique curve segments with trend similarity greater than the similarity threshold, the curve segment with the highest trend similarity can be taken as the first curve segment.

[0090] S30353: Along the time direction, determine the first target point located in the first curve segment in the historical gap curve, where the ordinate of the first target point corresponds to the first gap G1 of the most recent acquisition.

[0091] In this embodiment, the first fitted slope of the last segment of the first gap curve can be calculated. The last segment refers to the segment before the first gap G1, and the length of the ordinate corresponding to the last segment is equal to a preset value. The first curve segment is then divided into multiple sub-segments, and the length of the ordinate corresponding to each sub-segment is also equal to a preset value. Next, the second fitted slope of each sub-segment is calculated, and the second fitted slope closest to the first fitted slope is determined. The sub-segment corresponding to the second fitted slope closest to the first fitted slope is determined as the first target sub-segment corresponding to the last segment, and the end point of the first target sub-segment is determined as the first target point.

[0092] S30354: Determine the first adjustment time based on the x-coordinate corresponding to the first target point.

[0093] In this embodiment, the application can traverse all sub-segments after the first target sub-segment, determine the first sub-segment whose fitting slope difference with the first target sub-segment is greater than a preset slope threshold, and determine it as the second target sub-segment.

[0094] Furthermore, the end point or the midpoint of the vertical coordinate on the second target sub-segment is determined as the third target point. The difference in the horizontal coordinate between the third target point and the first target point is calculated to obtain a second difference. In this embodiment, after calculating the second difference, the current timestamp is obtained, and the current timestamp and the second difference are summed to obtain the first adjustment time.

[0095] In some implementations, if the first target sub-segment is the last among all sub-segments, the current timestamp can be obtained, and the difference between the current timestamp and a preset time can be summed to obtain the first adjustment time. For example, the preset time difference can be equal to 5 minutes, 10 minutes, or 15 minutes, and this application embodiment does not specifically limit it.

[0096] In this way, the first adjustment time can be determined.

[0097] Additionally, PLC 2003 can also be configured to perform the following steps S30355-S30358.

[0098] S30355: Based on the first prediction model, determine the historical compression curve that matches the second seal compression curve.

[0099] S30356: Determine a second curve segment from the matched historical compression curves; wherein the trend similarity between the second curve segment and the first sealing compression curve is greater than the similarity threshold.

[0100] In this embodiment, the historical compression curve matching the second sealing compression curve is divided into multiple continuous curve segments according to a time window. It is worth noting that the length of the time window is equal to the period corresponding to the second preset frequency × N. For example, when the second preset frequency is 5 minutes / time and N equals 10, the time window can be equal to 50 minutes.

[0101] Subsequently, embodiments of this application can calculate the trend similarity between the first sealing compression curve and each curve segment. Specifically, embodiments of this application can employ algorithms such as Dynamic Time Warping (DTW), correlation coefficient, or least squares method to calculate the similarity between the first sealing compression curve and each curve segment, thereby obtaining the trend similarity between the first sealing compression curve and each curve segment. Further, curve segments with trend similarity greater than a similarity threshold are designated as second curve segments. It should be noted that when curve segments with trend similarity greater than the similarity threshold are not unique, the curve segment with the highest trend similarity can be designated as the second curve segment.

[0102] S30357: Along the time direction, determine the second target point located in the second curve segment in the historical compression curve, where the ordinate of the second target point corresponds to the most recently collected sealing compression C.

[0103] In this embodiment, the third fitted slope of the last segment of the first sealing compression curve can be calculated. The last segment refers to the segment before the sealing compression C, and the length of the ordinate corresponding to the last segment is equal to a preset value. The second curve segment is then divided into multiple sub-segments, and the length of the ordinate corresponding to each sub-segment is also equal to a preset value. Next, the fourth fitted slope of each sub-segment is calculated, and the fourth fitted slope closest to the third fitted slope is determined. The sub-segment corresponding to the fourth fitted slope closest to the third fitted slope is determined as the second target sub-segment corresponding to the last segment, and the end point of the second target sub-segment is determined as the second target point.

[0104] S30358: Determine the second adjustment time based on the x-coordinate corresponding to the second target point.

[0105] In this embodiment, the application can traverse all sub-segments after the second target sub-segment, determine the first sub-segment whose fitting slope difference with the second target sub-segment is greater than a preset slope threshold, and identify it as the second target sub-segment.

[0106] Furthermore, the last point or the midpoint of the vertical coordinate on the second target sub-segment is determined as the fourth target point. The difference in the horizontal coordinate between the fourth target point and the second target point is calculated to obtain a third difference. In this embodiment, after calculating the third difference, the timestamp of the current moment can be obtained, and the timestamp of the current moment can be summed with the third difference to obtain a second adjustment time. In some implementations, if the second target sub-segment is the last of all sub-segments, the timestamp of the current moment can be obtained, and the difference between the timestamp of the current moment and a preset time can be summed to obtain the second adjustment time.

[0107] In this embodiment of the application, the specific execution logic of steps S30355-S30358 can be referred to the steps described above in S30351-S30354, and will not be repeated here.

[0108] Furthermore, the PLC 2003 can also be configured to perform the following steps S401-S403.

[0109] S401: Collect the second adjustment time determined M times before the current time according to the third preset frequency; where M is a preset value.

[0110] For example, the third preset frequency is once per hour, and M can be equal to 5, 10, or 15. This application embodiment does not specifically limit this. In practical applications, the parameters can be dynamically adjusted according to the aging characteristics of the mechanical seal 1005: for high-loss conditions (such as high-temperature and high-pressure environments), the third preset frequency can be shortened to once every 30 minutes, while M=15 is used to retain more historical data; for low-loss conditions, the frequency can be maintained once per hour, and M=5 is sufficient to meet the prediction requirements. During the data collection process, the operating parameters (such as medium temperature and operating pressure) corresponding to each second adjustment time need to be recorded synchronously, and abnormal adjustment times caused by sudden failures (such as values ​​deviating from the normal range by more than 3 times) should be removed to ensure the validity of the input data.

[0111] S402: Input the second adjustment time determined M times before the current time into the second prediction model, and use the second prediction model to predict the aging time of mechanical seal 1005.

[0112] The second prediction model can be a time series prediction model based on a Long Short-Term Memory (LSTM) network. This model achieves prediction by learning the changing trend of the second adjustment time (such as the pattern of gradually shortening with aging). For example, the second prediction model can first normalize the M second adjustment times, transforming them into sequence data within the [0,1] interval; then extract the features of the M second adjustment times through a sliding window to capture the dependencies of the time series; finally, output the changing trend of the future adjustment time through a multi-layer LSTM network, and calculate the aging time of the mechanical seal 1005 (i.e., the time point when the adjustment time shortens to the preset failure threshold).

[0113] S403: Generate the first alarm message at the target time point, which is before the aging time and has a preset time interval between it and the aging time.

[0114] In this way, by continuously collecting historical adjustment time, using time series models to predict trends, and triggering alarms in advance, the aging time of mechanical seal 1005 can be accurately predicted and warned in advance, reducing production interruptions caused by sudden failures.

[0115] Furthermore, the PLC 2003 can also be configured to perform the following step S501: if the first adjustment time or the second adjustment time is less than the first time threshold, generate a first alarm message.

[0116] Understandably, if the first adjustment time is less than the first time threshold, it indicates that the current growth rate of the first gap G1 is abnormally fast, and an alarm should be issued promptly. If the second adjustment time is less than the first time threshold, it indicates that the sealing performance of the mechanical seal 1005 is rapidly deteriorating, and an alarm should also be issued. For example, the first time threshold can be equal to 30 minutes, and this application embodiment does not specifically limit it.

[0117] And / or, PLC 2003 can also be configured to perform the following step S502: if the time difference between two adjacent first adjustment times is less than a second time threshold, generate a second alarm message.

[0118] The second time threshold can be less than the first time threshold; for example, the second time threshold could be 10 minutes. It is understood that if two adjacent adjustment times are too close together, it indicates an abnormal gap growth rate, and an alarm should be issued promptly.

[0119] And / or, PLC 2003 can also be configured to perform the following step S503: generate a third alarm message if the time difference between two adjacent second adjustment times is less than a third time threshold.

[0120] The third time threshold can be less than the first time threshold; for example, the third time threshold can be 10 minutes. It is understood that if two adjacent adjustment times are too close, it indicates that the sealing state of the mechanical seal 1005 is changing too rapidly, and an alarm should be issued promptly.

[0121] Furthermore, the PLC 2003 can also be configured to perform the following step S601: if the first difference D1 is greater than the difference threshold, generate a fourth alarm message.

[0122] For example, the difference threshold can be equal to 1mm. When the first difference D1 is greater than the difference threshold, it can be determined that the gap is too large and an alarm should be issued in time.

[0123] As can be seen from the above, the automatic control system for the chemical process pump provided in this application embodiment can solve the drawbacks of traditional shutdown maintenance and ensure production continuity. Without shutdown, key parameters are collected in real time through the gap detection module 2001 and the compression detection module 2002, and intelligently analyzed by the PLC 2003. It can dynamically adjust the gap and sealing state, and combined with the first prediction model to predict the adjustment time, achieving precise coordinated control of the "gap-seal" relationship and reducing human error. The system can also predict the aging time of the mechanical seal 1005 using the second prediction model, and can generate multi-level alarms based on anomalies such as adjustment time and difference, proactively avoiding risks such as leakage. Furthermore, it can adapt to different operating conditions to adjust parameters, ensuring pump efficiency and sealing reliability, and reducing production interruption losses.

[0124] Figure 4 This is a schematic flowchart of an automatic control method for a chemical process pump provided in an embodiment of this application.

[0125] This application also provides an automatic control method for a chemical process pump, which can be applied to the aforementioned chemical process pump. The method includes the following steps S701-S704.

[0126] S701: In response to the first control command, acquire the first gap G1 between the impeller and the front wear-resistant plate; S702: In response to the second control command, the compression amount of the mechanical seal is collected to obtain the sealing compression amount C; the sealing compression amount is proportional to the degree of compression of the elastic element of the mechanical seal; S703: Based on the most recently acquired first gap G1 and the most recently acquired sealing compression C, generate a real-time comprehensive quantity Q according to the first preset frequency; and calculate the first difference D1 between the first gap G1 and the standard gap G according to the first preset frequency. S704: When the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression quantity C is less than the first compression quantity limit C1, a third control command is generated based on the first difference D1 and the third control command is sent to the first drive module so that the first drive module drives the first adjusting screw, thereby reducing the axial clearance between the front wear plate and the impeller by the first difference D1. The method also includes the following steps S705-S707.

[0127] S705: According to the second preset frequency, the first gap G1 and sealing compression C collected N times before the current time are input into the first prediction model, and the first prediction model is used to predict the first adjustment time and the second adjustment time; the first adjustment time and the second adjustment time may be the same or different. S706: When the first adjustment time arrives, a new first control command is generated; S707: When the second adjustment time arrives, generate a new second control command.

[0128] In one implementation, after step S703, the following step S708 may also be included: when the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1, and the sealing compression quantity C is greater than or equal to the first compression quantity limit C1 and less than the second compression quantity limit C2, a fourth control command is generated based on the first preset value, and the fourth control command is sent to the second drive module so that the second drive module drives the second adjusting screw, thereby reducing the axial clearance between the front wear-resistant plate and the impeller by the first preset value.

[0129] In one implementation, after step S703, the following step S709 may be included: when the sealing compression amount C is greater than or equal to the second compression limit C2, a fifth control command is generated based on the second preset value, and the fifth control command is sent to the second drive module so that the second drive module drives the second adjusting screw, thereby reducing the axial clearance between the front wear plate and the impeller by the second preset value; wherein, the second preset value is greater than the first preset value.

[0130] In one implementation, step S705 may include the following steps S7051-S7055.

[0131] S7051: Collect the real-time operating conditions of the chemical process pump according to the second preset frequency. The real-time operating conditions include real-time speed, pump outlet pressure, conveying medium temperature, motor output power and / or bearing temperature. S7052: Identify multiple historical curves that match real-time operating conditions; S7053: Generate a first gap curve based on the first gap G1 collected N times before the current time, and generate a second gap curve based on all first gaps G1. The first gap curve and the second gap curve are curves of the first gap G1 changing over time. S7054: and, based on the sealing compression amount C collected N times before the current time, a first sealing compression amount curve is generated, and based on all sealing compression amounts C, a second sealing compression amount curve is generated, the first sealing compression amount curve and the second sealing compression amount curve are curves of sealing compression amount C changing with time. S7055: Input multiple historical curves, the first gap curve, the second gap curve, the first seal compression curve, and the second seal compression curve into the first prediction model to determine the first adjustment time and the second adjustment time.

[0132] In one implementation, the multiple historical curves include multiple historical gap curves and multiple historical compression curves; step S7055 may include the following steps S70551-S70554: S70551: Determine the historical gap curve that matches the second gap curve based on the first prediction model; S70552: Determine the first curve segment from the matched historical gap curves; wherein the trend similarity between the first curve segment and the first gap curve is greater than the similarity threshold; S70553: Along the time direction, determine the first target point located in the first curve segment in the historical gap curve, wherein the ordinate of the first target point corresponds to the first gap G1 of the most recent acquisition; S70554: Determine the first adjustment time based on the x-coordinate corresponding to the first target point; Furthermore, step S7055 may also include the following steps S70555-S70558.

[0133] S70555: Based on the first prediction model, determine the historical compression curve that matches the second sealing compression curve; S70556: Determine a second curve segment from the matched historical compression curves; wherein the trend similarity between the second curve segment and the first sealed compression curve is greater than the similarity threshold; S70557: Along the time direction, determine the second target point located in the second curve segment in the historical compression curve, where the ordinate of the second target point corresponds to the most recently collected sealing compression C; S70558: Determine the second adjustment time based on the x-coordinate corresponding to the second target point.

[0134] In one implementation, the method may further include the following steps S801-S803.

[0135] S801: Collect the second adjustment time determined M times before the current time according to the third preset frequency; where M is a preset value; S802: Input the second adjustment time determined M times before the current time into the second prediction model, and use the second prediction model to predict the aging time of the mechanical seal; S803: Generate the first alarm message at the target time point, which is before the aging time and has a preset time interval between it and the aging time.

[0136] In one implementation, the method may further include the following step S804: generating a first alarm message when the first adjustment time or the second adjustment time is less than a first time threshold; And / or, it also includes step S805: generating a second alarm message if the time difference between two adjacent first adjustment times is less than a second time threshold; And / or, it also includes step S806: generating a third alarm message if the time difference between two adjacent second adjustment times is less than a third time threshold.

[0137] In one implementation, the method may further include the following step S807: if the first difference D1 is greater than the difference threshold, a fourth alarm message is generated.

[0138] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0139] like Figure 5 As shown, this application provides an electronic device including a processor 10 and a memory 20. The memory 20 stores a computer program, and the processor 10 is configured to run the computer program to execute the steps in any of the above embodiments of the automatic control method for a chemical process pump.

[0140] In a specific implementation, the present invention also provides a computer storage medium, wherein the computer storage medium may store a program, which, when executed, may include some or all of the steps of the various embodiments of the automatic control method for chemical process pumps provided by the present invention. The storage medium may be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0141] It is readily understood that, based on the several embodiments provided in this application, those skilled in the art can combine, split, or reorganize the embodiments of this application to obtain other embodiments, none of which exceed the protection scope of this application.

[0142] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. An automatic control system for a chemical process pump, characterized in that, This invention relates to a chemical process pump, comprising at least: a pump body, an impeller, a front wear-resistant plate, a first adjusting screw, and a mechanical seal. The pump body and the impeller are axially opposite each other. The front wear-resistant plate is located inside the pump body and axially opposite to the impeller. The first adjusting screw passes axially through the pump body and abuts against the front wear-resistant plate, driving the front wear-resistant plate to move relative to the impeller to reduce the axial clearance between the front wear-resistant plate and the impeller. The mechanical seal includes an elastic element for providing axial sealing to the chemical process pump through axial elastic deformation. The system includes: The gap detection module is configured to: in response to a first control command, acquire a first gap G1 between the impeller and the front wear-resistant plate; The compression detection module is configured to: in response to a second control command, acquire the compression of the mechanical seal to obtain the sealing compression C; the sealing compression C is proportional to the degree of compression of the elastic element of the mechanical seal; The programmable logic controller (PLC) is configured to: generate a real-time comprehensive quantity Q based on the most recently acquired first gap G1 and the most recently acquired sealing compression quantity C at a first preset frequency; and calculate a first difference D1 between the first gap G1 and the standard gap G at the first preset frequency. When the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression quantity C is less than the first compression quantity limit C1, a third control command is generated based on the first difference D1 and the third control command is sent to the first drive module so that the first drive module drives the first adjusting screw, thereby reducing the axial clearance between the front wear-resistant plate and the impeller by the first difference D1. Furthermore, the PLC is configured to: input the first gap G1 and the sealing compression amount C collected N times prior to the current moment into the first prediction model according to the second preset frequency, and use the first prediction model to predict the first adjustment time and the second adjustment time; the first adjustment time may be the same as or different from the second adjustment time; When the first adjustment time arrives, a new first control command is generated and sent to the gap detection module; When the second adjustment time arrives, a new second control command is generated and sent to the compression detection module.

2. The automatic control system for the chemical process pump according to claim 1, characterized in that, The chemical process pump further includes a first bearing, a rear bearing cover, and a second adjusting screw. The first bearing is axially connected to the impeller. The rear bearing cover is located on the side of the first bearing away from the impeller. The second adjusting screw passes through the rear bearing cover axially and abuts against the first bearing. The second adjusting screw is used to drive the first bearing and the impeller to move toward the pump body to reduce the axial clearance between the front wear plate and the impeller. The PLC is also configured to: When the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1, and the sealing compression quantity C is greater than or equal to the first compression quantity limit C1 and less than the second compression quantity limit C2, a fourth control command is generated based on the first preset value, and the fourth control command is sent to the second drive module so that the second drive module drives the second adjusting screw, thereby reducing the axial clearance between the front wear-resistant plate and the impeller by the first preset value.

3. The automatic control system for the chemical process pump according to claim 2, characterized in that, The PLC is also configured to: When the sealing compression amount C is greater than or equal to the second compression limit C2, a fifth control command is generated based on the second preset value, and the fifth control command is sent to the second drive module so that the second drive module drives the second adjusting screw, thereby reducing the axial clearance between the front wear-resistant plate and the impeller by the second preset value; wherein, the second preset value is greater than the first preset value.

4. The automatic control system for the chemical process pump according to claim 1, characterized in that, The PLC is also configured to: According to the second preset frequency, the real-time operating conditions of the chemical process pump are collected, including real-time speed, pump outlet pressure, conveying medium temperature, motor output power and / or bearing temperature. Identify multiple historical curves that match the real-time operating conditions; A first gap curve is generated based on the first gap G1 collected N times before the current moment, and a second gap curve is generated based on all the first gaps G1. The first gap curve and the second gap curve are curves of the first gap G1 changing over time. Furthermore, the PLC is also configured to: A first sealing compression curve is generated based on the sealing compression amount C collected N times prior to the current moment, and a second sealing compression curve is generated based on all the sealing compression amounts C. The first sealing compression curve and the second sealing compression curve are curves of the sealing compression amount C changing over time. The first adjustment time and the second adjustment time are determined by inputting multiple historical curves, the first gap curve, the second gap curve, the first seal compression curve, and the second seal compression curve into the first prediction model.

5. The automatic control system for the chemical process pump according to claim 4, characterized in that, The multiple historical curves include multiple historical gap curves and multiple historical compression curves; the PLC is also configured to: The historical gap curve that matches the second gap curve is determined based on the first prediction model; A first curve segment is determined from the matched historical gap curves; wherein the trend similarity between the first curve segment and the first gap curve is greater than a similarity threshold; Along the time direction, a first target point located in the first curve segment is determined in the historical gap curve, wherein the ordinate of the first target point corresponds to the first gap G1 of the most recent acquisition; The first adjustment time is determined based on the x-coordinate corresponding to the first target point; Furthermore, the PLC is also configured to: The historical compression curve that matches the second sealing compression curve is determined based on the first prediction model; A second curve segment is determined from the matched historical compression curves; wherein the trend similarity between the second curve segment and the first sealing compression curve is greater than the similarity threshold. Along the time direction, a second target point is determined in the second curve segment of the historical compression curve, wherein the ordinate of the second target point corresponds to the most recently collected sealing compression C; The second adjustment time is determined based on the x-coordinate corresponding to the second target point.

6. The automatic control system for the chemical process pump according to claim 1, characterized in that, The PLC is also configured to: According to the third preset frequency, the second adjustment time determined M times before the current time is collected; where M is a preset value; The second adjustment time, determined M times prior to the current moment, is input into the second prediction model, and the aging time of the mechanical seal is predicted using the second prediction model. A first alarm message is generated at a target time point, which is located before the aging time and has a preset time interval between it and the aging time.

7. The automatic control system for the chemical process pump according to claim 1, characterized in that, The PLC is also configured to: If either the first adjustment time or the second adjustment time is less than the first time threshold, a first alarm message is generated. And / or, if the time difference between two consecutive first adjustment times is less than the second time threshold, a second alarm message is generated; And / or, if the time difference between two consecutive second adjustment times is less than a third time threshold, a third alarm message is generated.

8. The automatic control system for the chemical process pump according to claim 1, characterized in that, The PLC is also configured to: If the first difference D1 is greater than the difference threshold, a fourth alarm message is generated.

9. An automatic control method for a chemical process pump, characterized in that, This invention relates to a chemical process pump, comprising at least: a pump body, an impeller, a front wear-resistant plate, a first adjusting screw, and a mechanical seal. The pump body and the impeller are axially opposite each other. The front wear-resistant plate is located inside the pump body and axially opposite to the impeller. The first adjusting screw passes axially through the pump body and abuts against the front wear-resistant plate, driving the front wear-resistant plate to move relative to the impeller to reduce the axial clearance between the front wear-resistant plate and the impeller. The mechanical seal includes an elastic element for providing axial sealing to the chemical process pump through axial elastic deformation. The method includes: In response to the first control command, the first gap G1 between the impeller and the front wear-resistant plate is collected; In response to the second control command, the compression amount of the mechanical seal is acquired to obtain the sealing compression amount C; the sealing compression amount C is proportional to the degree of compression of the elastic element of the mechanical seal; According to the first preset frequency, based on the most recently collected first gap G1 and the most recently collected sealing compression amount C, a real-time comprehensive quantity Q is generated; and according to the first preset frequency, a first difference D1 between the first gap G1 and the standard gap G is calculated. When the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1 and the sealing compression quantity C is less than the first compression quantity limit C1, a third control command is generated based on the first difference D1 and the third control command is sent to the first drive module so that the first drive module drives the first adjusting screw, thereby reducing the axial clearance between the front wear-resistant plate and the impeller by the first difference D1. Furthermore, the method further includes: inputting the first gap G1 and the sealing compression amount C collected N times before the current moment into a first prediction model according to a second preset frequency, and using the first prediction model to predict a first adjustment time and a second adjustment time; the first adjustment time may be the same as or different from the second adjustment time; When the first adjustment time arrives, a new first control command is generated; When the second adjustment time arrives, a new second control command is generated.

10. An electronic device, characterized in that, include: One or more processors; as well as, The memory is configured to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the automatic control method for chemical process pumps according to claim 9.

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