An automatic control system and method for a chemical process pump

Abstract

The application 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; a compression amount detection module configured to collect a compression amount of a mechanical seal to obtain a sealing compression amount C; and a programmable logic controller (PLC) configured to generate a third control instruction based on a first difference D1 and send the third control instruction to a first driving module to drive the first driving module to drive a first adjusting top screw to reduce an axial gap between the front wear plate and the impeller by the first difference D1 when a real-time comprehensive amount Q is greater than a comprehensive amount threshold Q1 and the sealing compression amount C is less than a first compression amount limit C1. The system can realize collaborative and accurate control of the gap and the seal, improve the operation safety, ensure the continuous chemical production, and reduce the downtime loss.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automatic control, and particularly relates to an automatic control system and method for a chemical process pump. BACKGROUND

[0002] The chemical process pump is a centrifugal pump specially designed for chemical production, which is used to continuously and stably transport corrosive, toxic, flammable or high-temperature and high-pressure liquids (acid, alkali, solvent, slurry, etc.), and is one of the core equipment in the chemical production process.

[0003] However, during the operation of the chemical process pump, there are some operation losses, such as changes in the assembly state. In the existing processing process, in order to check the assembly state, the shutdown maintenance means is generally adopted, but the shutdown maintenance will hinder the production work, resulting in a reduction in production efficiency. SUMMARY

[0004] The embodiments of the present application provide an automatic control system and method for a chemical process pump, to solve the problem of difficult maintenance of the chemical process pump.

[0005] In a first aspect, the embodiments of the present application provide an automatic control system of a chemical process pump, which is applied to the chemical process pump. The chemical process pump at least includes a pump body, an impeller, a front wear plate, a first adjusting top screw and a mechanical seal. The pump body and the impeller are arranged opposite to each other along an axial direction. The front wear plate is located inside the pump body and arranged opposite to the impeller along the axial direction. The first adjusting top screw passes through the pump body along the axial direction and abuts against the front wear plate, and is used to drive the front wear plate to move relative to the impeller, so as to reduce an axial gap between the front wear plate and the impeller. The mechanical seal includes an elastic element, which is used to provide an axial seal for the chemical process pump through axial elastic deformation. The system includes: a gap detection module configured to collect a first gap G1 between the impeller and the front wear plate in response to a first control instruction; a compression amount detection module configured to collect a compression amount of the mechanical seal in response to a second control instruction, to obtain a seal compression amount C. The seal compression amount C is proportional to a compression degree of the elastic element of the mechanical seal; a programmable logic controller (PLC) configured to: generate a real-time comprehensive amount Q based on the first gap G1 collected last time and the seal compression amount C collected last time according to a first preset frequency; and calculate a first difference D1 between the first gap G1 and a standard gap G according to the first preset frequency; in a case where the real-time comprehensive amount Q is greater than a comprehensive amount threshold Q1 and the seal compression amount C is less than a first compression amount limit C1, generate a third control instruction based on the first difference D1, and issue the third control instruction to a first driving module, so that the first driving module drives the first adjusting top screw, and then reduces the axial gap between the front wear plate and the impeller by the first difference D1; and the PLC is further configured to: input the first gap G1 collected N times before the current time and the seal compression amount C to a first prediction model according to a second preset frequency, and predict a first adjusting time and a second adjusting time by using the first prediction model. The first adjusting time is the same as or different from the second adjusting time; generate a new first control instruction when the first adjusting time comes; and generate a new second control instruction when the second adjusting time comes.

[0006] In a possible implementation, the chemical process pump further includes a first bearing, a rear bearing cover and a second adjusting top screw. The first bearing is connected to the impeller along the axial direction. The rear bearing cover is located on a side of the first bearing away from the impeller. The second adjusting top screw passes through the rear bearing cover along the axial direction and abuts against the first bearing. The second adjusting top screw is used to drive the first bearing and the impeller to move towards the pump body, so as to reduce the axial gap between the front wear plate and the impeller. The PLC is further configured to: in a case where the real-time comprehensive amount Q is greater than the comprehensive amount threshold Q1, and the seal compression amount C is greater than or equal to the first compression amount limit C1 and less than a second compression amount limit C2, generate a fourth control instruction based on a first preset value, and issue the fourth control instruction to a second driving module, so that the second driving module drives the second adjusting top screw, and then reduces the axial gap between the front wear plate and the impeller by the first preset value.

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

[0008] In a possible implementation, the PLC is further configured to: collect real-time working conditions of the chemical process pump at a second preset frequency, the real-time working conditions including a real-time rotating speed, a pump body outlet pressure, a conveying medium temperature, a motor output power, and / or a bearing temperature; determine a plurality of historical curves matched with the real-time working conditions; 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 the 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 amount curve based on the sealing compression amount C collected N times before the current time, and generate a second sealing compression amount curve based on all the sealing compression amounts C, the first sealing compression amount curve and the second sealing compression amount curve being curves of the sealing compression amount C changing over time; and input the plurality of historical curves, the first gap curve, the second gap curve, the first sealing compression amount curve, and the second sealing compression amount curve into the first prediction model to determine the first adjusting time and the second adjusting time.

[0009] In a possible implementation, the plurality of historical curves include a plurality of historical gap curves and a plurality of historical compression amount curves; the PLC is further configured to: determine a historical gap curve matched with the second gap curve based on the first prediction model; determine a first curve segment in the matched historical gap curve; the similarity between the first curve segment and the first gap curve is greater than a similarity threshold; determine a first target point in the historical gap curve in the time direction and located in the first curve segment, the vertical coordinate corresponding to the first target point corresponding to the first gap G1 collected most recently; determine the first adjusting time based on the horizontal coordinate corresponding to the first target point; and the PLC is further configured to: determine a historical compression amount curve matched with the second sealing compression amount curve based on the first prediction model; determine a second curve segment in the matched historical compression amount curve; the similarity between the second curve segment and the first sealing compression amount curve is greater than the similarity threshold; determine a second target point in the historical compression amount curve in the time direction and located in the second curve segment, the vertical coordinate corresponding to the second target point corresponding to the sealing compression amount C collected most recently; and determine the second adjusting time based on the horizontal coordinate corresponding to the second target point.

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

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

[0012] In a possible implementation, the PLC is further configured to: generate the fourth alarm information in a case where the first difference D1 is greater than a difference threshold.

[0013] In a second aspect, the embodiments of the present application provide an automatic control method of a chemical process pump, applied to the chemical process pump, the chemical process pump comprising at least: a pump body, an impeller, a front wear plate, a first adjusting top screw, and a mechanical seal, the pump body and the impeller being arranged opposite to each other in an axial direction, the front wear plate being arranged inside the pump body and opposite to the impeller in the axial direction, the first adjusting top screw penetrating through the pump body in the axial direction and abutting against the front wear plate, for driving the front wear plate to move relative to the impeller to reduce an axial gap between the front wear plate and the impeller, and the mechanical seal comprising an elastic element, for providing an axial seal for the chemical process pump through axial elastic deformation; the method comprising: in response to a first control instruction, collecting a first gap G1 between the impeller and the front wear plate; in response to a second control instruction, collecting a compression amount of the mechanical seal to obtain a sealing compression amount C; the sealing compression amount being proportional to a compression degree of the elastic element of the mechanical seal; generating a real-time comprehensive amount Q based on the first gap G1 collected last time and the sealing compression amount C collected last time according to a first preset frequency; and calculating a first difference D1 between the first gap G1 and a standard gap G according to the first preset frequency; in a case where the real-time comprehensive amount Q is greater than a comprehensive amount threshold Q1 and the sealing compression amount C is less than a first compression amount limit C1, generating a third control instruction based on the first difference D1 and issuing the third control instruction to a first driving module, so that the first driving module drives the first adjusting top screw, and then reduces the axial gap between the front wear plate and the impeller by the first difference D1; and the method further comprising: inputting the first gap G1 and the sealing compression amount C collected N times before a current time to a first prediction model according to a second preset frequency, and predicting a first adjusting time and a second adjusting time by using the first prediction model; the first adjusting time being the same as or different from the second adjusting time; generating a new first control instruction and issuing the new first control instruction to a gap detection module when the first adjusting time arrives; and generating a new second control instruction and issuing the new second control instruction to a compression amount detection module when the second adjusting time arrives.

[0014] In a third aspect, the embodiments of the present application further provide an electronic device, comprising: 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 of the chemical process pump according to the second aspect.

[0015] From the above, the embodiment of the application provides an automatic control system of a chemical process pump, which is applied to the chemical process pump, and the chemical process pump at least comprises a pump body, an impeller, a front wear plate, a first adjusting top screw and a mechanical seal, the pump body and the impeller are arranged opposite along an axial direction, the front wear plate is located in the pump body and arranged opposite to the impeller along the axial direction, the first adjusting top screw passes through the pump body along the axial direction and abuts against the front wear plate, and is used for driving the front wear plate to move relative to the impeller, so as to reduce an axial gap between the front wear plate and the impeller; the mechanical seal comprises an elastic element, and is used for providing axial sealing for the chemical process pump through axial elastic deformation; the system comprises: a gap detection module configured to: in response to a first control instruction, collect a first gap G1 between the impeller and the front wear plate; a compression amount detection module configured to: in response to a second control instruction, collect a compression amount of the mechanical seal to obtain a sealing compression amount C; the sealing compression amount is proportional to a compression degree of the elastic element of the mechanical seal; a programmable logic controller (PLC) configured to: according to a first preset frequency, generate a real-time comprehensive amount Q based on the last collected first gap G1 and the last collected sealing compression amount C; and according to the first preset frequency, calculate a first difference D1 between the first gap G1 and a standard gap G; in the case that the real-time comprehensive amount Q is greater than a comprehensive amount threshold Q1 and the sealing compression amount C is less than a first compression amount limit C1, a third control instruction is generated based on the first difference D1, and the third control instruction is issued to the first driving module, so that the first driving module drives the first adjusting top screw, and then the axial gap between the front wear plate and the impeller is reduced by the first difference D1; and the PLC is further configured to: according to a second preset frequency, input the first gap G1 and the sealing compression amount C collected N times before the current time to a first prediction model, and predict a first adjusting time and a second adjusting time by using the first prediction model; the first adjusting time is the same as or different from the second adjusting time; when the first adjusting time comes, a new first control instruction is generated and issued to the gap detection module; and when the second adjusting time comes, a new second control instruction is generated and issued to the compression amount detection module. The system can realize "gap-seal" collaborative precise control, the detection time is predicted in advance by using the prediction model, and manual error is reduced; and the system can also prewarn seal leakage, improve operation safety, guarantee continuous chemical production, and reduce downtime loss. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A first structure diagram of the chemical process pump provided by the embodiment of the application;

[0017] Figure 2 A second structure diagram of the chemical process pump provided by the embodiment of the application;

[0018] Figure 3 A structure diagram of the automatic control system of the chemical process pump provided by the embodiment of the application;

[0019] Figure 4 A flowchart of an automatic control method of a chemical process pump is provided for the embodiments of the present application.

[0020] Figure 5 A structural diagram of an electronic device is provided for the embodiments of the present application.

[0021] Among them, the processor-10; memory-20; pump body-1001; impeller-1002; front wear plate-1003; first adjusting top wire-1004; mechanical seal-1005; first bearing-1006; rear bearing cover-1007; second adjusting top wire-1008; shaft-1009; bearing suspension-1010; sealing ring-1011; plug-1012; pump foot-1013; impeller nut-1014; front bearing cover-1015; front baffle-1016; impeller key-1017; lifting ring screw-1018; bleeder plug-1019; pump cover pad-1020; coupling key-1021; round nut-1022; rear baffle-1023; impeller ring-1024; pump body 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 DESCRIPTION

[0022] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0023] In order to solve the problem of difficult detection of chemical process pumps, the present application provides an automatic control system and method for chemical process pumps. The method can realize dynamic adjustment of the gap and the sealing state by real-time acquisition of key parameters of the chemical process pump (axial gap of the front wear plate and the impeller, sealing compression amount of the mechanical seal), combined with intelligent analysis and prediction of the programmable logic controller (Programmable Logic Controller, PLC), without stopping to complete the assembly state monitoring and fault warning, which fundamentally avoids the influence of traditional shutdown maintenance on production continuity, while ensuring the operation efficiency and sealing reliability of the pump body.

[0024] Figure 1 A first structural diagram of a chemical process pump is provided for the embodiments of the present application.

[0025] As Figure 1 shown, the chemical process pump provided by the embodiment of the application can include a pump body 1001, an impeller 1002, a front wear plate 1003, a first adjusting top screw 1004, and a mechanical seal 1005. The pump body 1001 and the impeller 1002 are arranged opposite to each other in the axial direction. The impeller 1002 can be a semi-open impeller. The front wear plate 1003 is located inside the pump body 1001 and arranged opposite to the impeller 1002 in the axial direction. The first adjusting top screw 1004 passes through the pump body 1001 in the axial direction and abuts against the front wear plate 1003. The first adjusting top screw 1004 is used to drive the front wear plate 1003 to move relative to the impeller 1002, so as to reduce the axial gap between the front wear plate 1003 and the impeller 1002. The mechanical seal 1005 can include an elastic element, which is used to provide axial sealing for the chemical process pump through axial elastic deformation.

[0026] It should be noted that the axial sealing is a concept opposite to the radial sealing. The axial sealing is a sealing mode in which a sealing element is attached or blocked in a direction parallel to the axis of the rotating shaft, so as to prevent leakage of medium along the axial gap of the shaft. The radial sealing is a sealing mode in which a sealing element is compressed or attached in a radial direction perpendicular to the axis of the rotating shaft, so as to prevent leakage of medium along the radial fit gap between the shaft and the housing.

[0027] Figure 2 A second structural schematic diagram of the chemical process pump provided by the embodiment of the application is shown.

[0028] As Figure 2 shown, the chemical process pump can further include a first bearing 1006, a rear bearing cover 1007, and a second adjusting top screw 1008. The first bearing 1006 is connected to the impeller 1002 in the axial direction. The rear bearing cover 1007 is located on the side of the first bearing 1006 away from the impeller 1002. The second adjusting top screw 1008 passes through the rear bearing cover 1007 in the axial direction and abuts against the first bearing 1006. The second adjusting top screw 1008 is used to drive the first bearing 1006 and the impeller 1002 to move towards the pump body 1001, so as to reduce the axial gap between the front wear plate 1003 and the impeller 1002.

[0029] It can be understood that the above content is only a part of the structure of the chemical process pump. In order to realize the normal operation of the pump, the chemical process pump also includes other structures, such as a shaft 1009, a bearing suspension 1010, a sealing ring 1011, a plug 1012, a pump foot 1013, an impeller nut 1014, a front bearing cover 1015, a front baffle plate 1016, an impeller key 1017, a lifting ring screw 1018, a gas discharge plug 1019, a pump cover gasket 1020, a coupling key 1021, a round nut 1022, a rear baffle plate 1023, an impeller ring 1024, a pump body ring 1025, a pump cover 1026, a second bearing 1027, and a motor. For example, the sealing ring 1011 can be assembled at the stationary joint of the chemical process pump, which is also called the low-pressure static sealing position. The stationary joint is not in direct contact with the high-pressure medium. In simple terms, the stationary joint is the gap that needs to be sealed when the two non-rotating parts in the pump are placed together. The sealing ring 1011 can be an O-ring, which can be arranged at the static ring seat of the mechanical seal 1005, the stationary threads or flange joint surfaces of the pump cover 1026, the cooling water / washing liquid interface, the pressure / temperature gauge connector, etc., for providing radial and / or axial sealing. The embodiments of the present application do not make specific limitations on this.

[0030] It should be noted that the working principle of the mechanical seal 1005 is the axial fitting design of the sealing surface, which is as follows: the mechanical seal 1005 includes a dynamic ring (synchronously rotating with the shaft 1009 and fixed relative to the shaft 1009) and a static ring (not rotating with the shaft 1009), and the sealing end faces of the two are arranged in axial opposition (the end faces are perpendicular to the axis of the shaft 1009). During normal operation, the end faces of the dynamic ring and the static ring are tightly fitted under the axial elastic force of the elastic element (such as a spring or a bellows), forming an extremely narrow "sealing end face contact band" to provide axial sealing. The greater the compression amount of the elastic element, the greater the fitting pressure of the dynamic ring and the static ring, and the more reliable the sealing performance. It should be noted that excessive fitting pressure can also cause sealing failure, therefore, the compression amount should be maintained within a certain range.

[0031] Figure 3 The structure diagram of the automatic control system of the chemical process pump provided by the embodiments of the present application.

[0032] As Figure 3As shown, the automatic control system of the chemical process pump provided by the embodiments of the present application can include a gap detection module 2001, a compression amount detection module 2002, a programmable logic controller PLC 2003, a first driving module 2004, and a second driving module 2005. The gap detection module 2001 can be a non-contact displacement detection device, which detects the axial gap between the front wear plate 1003 and the impeller 1002, and accurately collects the gap between the front wear plate 1003 and the impeller 1002 in response to a first control instruction. The compression amount detection module 2002 can use a micro pressure sensor array, and the sensor probe of the micro pressure sensor array is embedded in the elastic element (such as a spring seat or a bellows tail) of the mechanical seal 1005. In response to a second control instruction, the feedback pressure generated by the elastic element under pressure is collected by the pressure sensor array, and the sealing compression amount of the mechanical seal 1005 is calculated. The conversion formula is as follows:

[0033] C = P x S / K;

[0034] Wherein, C represents the sealing compression amount; P represents the feedback pressure; S represents the force area of the elastic element; and K represents the stiffness parameter of the elastic element.

[0035] In some implementations, the sealing compression amount C = original free height of the sealing elastic element - actual height after compression. When the sealing elastic element is compressed, the linear size decreases (such as from 2.0 mm to 1.5 mm), and the C value (difference) increases synchronously, which intuitively reflects the proportional relationship between the compression degree and the sealing compression amount.

[0036] The programmable logic controller PLC 2003 as the core control unit of the system can be internally provided with a data storage module, a model operation module, and an instruction generation module, etc. The data storage module is used to store historical gap data, sealing compression amount data, and real-time working condition parameters (such as rotation speed and pressure); the model operation module is loaded 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), and can complete the adjustment time prediction and mechanical seal 1005 aging time calculation; and the instruction generation module generates first, second, and third control instructions according to the detection data and the model operation results, to realize the collaborative control of each module.

[0037] The first driving module 2004 is in transmission connection with the first adjusting top wire 1004, is composed of a stepping motor, a speed reduction gear set and a torque sensor, after receiving the third control instruction issued by the PLC 2003, the stepping motor adjusts the rotation angle according to the first difference D1 in the instruction, and the power is transmitted to the first adjusting top wire 1004 through the speed reduction gear set, so as to push the front wear plate 1003 to move towards the impeller 1002; the torque sensor monitors the load torque of the adjusting top wire in real time, and when the torque exceeds the preset threshold value (such as 50N·m), the signal is immediately fed back to the PLC 2003, triggering the pause of the adjusting action, so as to avoid excessive adjustment and cause the parts to be stuck.

[0038] The second driving module 2005 is in corresponding connection with the second adjusting top wire 1008, and the structure is consistent with that of the first driving module 2004, can respond to the fourth control instruction issued by the PLC 2003, and drive the second adjusting top wire 1008 to push the first bearing 1006 and the impeller 1002 to move towards the pump body 1001, so as to adapt to the gap adjusting demand.

[0039] Further, the gap detection module 2001 can be configured to perform the following step S100.

[0040] S100: in response to the first control instruction, collecting the first gap G1 between the impeller 1002 and the front wear plate 1003.

[0041] Wherein, the PLC 2003 can be in communication connection with the gap detection module 2001, and the first control instruction can be issued by the PLC 2003. And the gap detection module 2001 can return the collected first gap G1 to the PLC 2003.

[0042] The compression amount detection module 2002 is configured to perform the following step S200.

[0043] S200: in response to the second control instruction, collecting the compression amount of the mechanical seal 1005 to obtain the sealing compression amount C; the sealing compression amount is proportional to the compression degree of the elastic element of the mechanical seal 1005.

[0044] Wherein, the PLC 2003 can be in communication connection with the compression amount detection module 2002, and the second control instruction can be issued by the PLC 2003. And the compression amount detection module 2002 can return the collected compression amount, i.e. the sealing compression amount C to the PLC 2003.

[0045] Further, the sealing compression amount C is directly proportional to the compression degree of the mechanical seal 1005, which means that when the axial or radial pressure on the mechanical seal 1005 increases, the physical deformation degree (i.e., the compression degree) of the mechanical seal 1005 increases, the tightness of the mechanical seal 1005 and the mating surface is enhanced, and at this time, the sealing compression amount C value collected by the compression amount detection module 2002 will increase; on the contrary, when the compression degree of the mechanical seal 1005 decreases, the compression degree of the mechanical seal 1005 decreases, and at this time, the sealing compression amount C value detected will decrease. This direct proportion relationship provides an intuitive quantitative basis for the PLC 2003 to judge the sealing state. For example, the newly installed mechanical seal 1005 has a high compression degree, and C can be 0.2 mm (a large value), indicating that the sealing is good; and after being used for a period of time, if the sealing compression amount C decreases to 0.05-0.1 mm (a small value), it indicates that the sealing compression degree decreases, or increases to 0.25 mm, which indicates that the sealing compression state of the mechanical seal 1005 improves, which can be caused by the device assembly process.

[0046] It should be further pointed out that when the sealing compression amount C is too large, it means that the mechanical seal 1005 is compressed too much, which can cause plastic deformation, extrusion or accelerated aging of the mechanical seal 1005, thereby damaging the sealing effect and causing leakage. When the sealing compression amount C is too small, it means that the compression degree of the mechanical seal 1005 is low, and the compression amount is insufficient to generate sufficient contact stress to effectively fill the mating gap, which can also cause leakage. It can be seen that the sealing compression amount C has a normal working range, and when the real-time value of the sealing compression amount C is not in the normal working range, it indicates that the sealing state is abnormal, i.e., the assembly state between the devices is abnormal. In the embodiment of the present application, the normal working range can refer to the sealing compression amount C being less than the first compression amount limit C1 and greater than or equal to the third compression amount limit C3. The specific values of the first compression amount limit C1 and the third compression amount limit C3 can be determined based on actual conditions, and the first compression amount limit C1 is greater than the third compression amount limit C3, which is not limited in the embodiment of the present application.

[0047] The programmable logic controller PLC 2003 can be configured to perform the following steps S301-S302.

[0048] S301: According to the first preset frequency, based on the first gap G1 collected at the last time and the sealing compression amount C collected at the last time, 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.

[0049] It can be understood that the calculation steps of the real-time comprehensive quantity Q and the first difference D1 can be synchronized, i.e., the calculation periods are aligned.

[0050] The calculation formula of the real-time comprehensive quantity Q can be:

[0051] Q = a x (G1 / G) + b x |C2-C1 / (C2-C1);

[0052] Wherein, Q represents a real-time comprehensive quantity, G1 represents a first gap, G represents a standard gap; C1 represents a first compression amount limit value, C2 represents a second compression amount limit value, C represents a sealing compression amount. a and b are weight coefficients, and a+b=1, a>b, such as a taking 0.6 and b taking 0.4, the influence of the gap on the pump efficiency is preferentially emphasized.

[0053] It can be understood that the second compression amount limit value C2 is greater than the first compression amount limit value C1.

[0054] Through the formula, the sealing state of the first gap G1 and the sealing compression amount C can be quantitatively integrated. The greater the Q value, the more significant the comprehensive problem of "abnormal gap + abnormal sealing" of the pump body 1001 at present, which provides a quantitative basis for subsequent adjustment.

[0055] Further, the first difference D1=G1-G. The standard gap G can refer to the gap between the impeller 1002 and the front wear plate 1003 when the impeller 1002 and the front wear plate 1003 are assembled in a standard state. As the chemical process pump operates, the gap between the impeller 1002 and the front wear plate 1003 gradually increases, so the first difference D1 can be a positive value.

[0056] It should be noted that the first preset frequency can be 5 min / time or 10 min / time, which is not limited in the embodiment of the application.

[0057] S302: In the case that the real-time comprehensive quantity Q is greater than the comprehensive quantity threshold Q1, and the sealing compression amount C is less than the first compression amount limit value C1, a third control instruction is generated based on the first difference D1, and the third control instruction is issued to the first driving module 2004, so that the first driving module 2004 drives the first adjusting top screw 1004, and then the axial gap between the front wear plate 1003 and the impeller 1002 is reduced by the first difference D1.

[0058] 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, which can represent that there is a significant problem in the assembly state between the front wear plate 1003 and the impeller 1002, and the compression state of the mechanical seal 1005 does not exceed the normal state, so that the first adjusting top screw 1004 can drive the front wear plate 1003 to move relative to the impeller 1002, and at this time, the front wear plate 1003 can move towards the impeller 1002 to reduce the axial gap between the front wear plate 1003 and the impeller 1002. In this way, the assembly state between the front wear plate 1003 and the impeller 1002 can be improved, the pump efficiency and the motor output power can be improved, and energy waste can be avoided. It can be understood that since the sealing compression quantity C has not exceeded the limit, the gap can be restored by moving the front wear plate 1003 only, without adjusting the seal.

[0059] In addition, the PLC 2003 can also be configured to perform the following steps S303-S305.

[0060] S303: According to the second preset frequency, input the first gap G1 and the sealing compression quantity C collected N times before the current time to the first prediction model, and predict the first adjusting time and the second adjusting time by using the first prediction model; the first adjusting time and the second adjusting time are the same or different.

[0061] Wherein, the second preset frequency can be 5min / time or 10min / time, and N is equal to 10, for example, and the embodiments of the present application do not make specific limitation thereto.

[0062] Further, the first prediction model can be a dynamic prediction model, and the specific prediction steps will be described in detail below, which will not be repeated here.

[0063] It is worth noting that the first adjusting time and the second adjusting time are independent of each other in the calculation logic, and are respectively predicted based on the change trend of the respective parameters (such as the gap wear rate and the sealing aging rate). For example, if the gap wear rate is faster than the sealing aging rate, the first adjusting time can be earlier than the second adjusting time, and vice versa.

[0064] S304: When the first adjusting time comes, a new first control instruction is generated and sent to the gap detection module 2001.

[0065] In this way, a new round of gap detection can be triggered. If the first adjusting time is not equal to the second adjusting time, the compression quantity detection module 2002 can be in a dormant state at this time. That is, the working process between the gap detection module 2001 and the compression quantity detection module 2002 can be asynchronous.

[0066] S305: When the second adjusting time comes, a new second control instruction is generated and sent to the compression quantity detection module 2002.

[0067] In this way, a new round of compression amount detection can be triggered. If the second adjustment time is not equal to the first adjustment time, the gap detection module 2001 can be in a dormant state at this time.

[0068] From the above, the embodiments of the present application provide an automatic control system for a chemical process pump. The chemical process pump at least includes: a pump body 1001, an impeller 1002, a front wear plate 1003, a first adjustment top screw 1004, and a mechanical seal 1005. The pump body 1001 is connected to the impeller 1002 in the axial direction. The front wear plate 1003 is located inside the pump body 1001 and is arranged opposite to the impeller 1002 in the axial direction. The first adjustment top screw 1004 passes through the pump body 1001 in the axial direction and abuts against the front wear plate 1003. The first adjustment top screw 1004 is used to drive the front wear plate 1003 to move relative to the impeller 1002, so as to reduce the axial gap between the front wear plate 1003 and the impeller 1002. The mechanical seal 1005 includes an elastic element, which is used to provide axial sealing for the chemical process pump through axial elastic deformation. The system includes: a gap detection module 2001 configured to: in response to a first control instruction, collect a first gap G1 between the impeller 1002 and the front wear plate 1003; a compression amount detection module 2002 configured to: in response to a second control instruction, collect a compression amount of the mechanical seal 1005 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 1005; a programmable logic controller PLC 2003 configured to: at a first preset frequency, generate a real-time comprehensive amount Q based on the last collected first gap G1 and the last collected sealing compression amount C; and at the first preset frequency, calculate a first difference D1 between the first gap G1 and a standard gap G; in a case where the real-time comprehensive amount Q is greater than a comprehensive amount threshold Q1 and the sealing compression amount C is less than a first compression amount limit C1, generate a third control instruction based on the first difference D1 and issue the third control instruction to a first driving module 2004, so that the first driving module 2004 drives the first adjustment top screw 1004, and in turn reduces the axial gap between the front wear plate 1003 and the impeller 1002 by the first difference D1; and the PLC 2003 is further configured to: at a second preset frequency, input the first gap G1 and the sealing compression amount C collected N times before the current time to a first prediction model, and predict a first adjustment time and a second adjustment time by using the first prediction model. The first adjustment time and the second adjustment time are the same or different. When the first adjustment time comes, a new first control instruction is generated and issued to the gap detection module 2001. When the second adjustment time comes, a new second control instruction is generated and issued to the compression amount detection module 2002. The system can realize "gap-seal" collaborative precise control, predict the detection time in advance through the prediction model, and reduce the manual error. In addition, the system can warn the seal leakage, improve the operation safety, and also can ensure the continuous chemical production and reduce the downtime loss.

[0069] Further, the PLC 2003 can also be configured to perform the following step S306:

[0070] S306: In the case that 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 instruction is generated based on a first preset value, and the fourth control instruction is sent to the second driving module 2005 to drive the second adjusting top screw 1008, so as to reduce the axial gap between the front wear plate 1003 and the impeller 1002 by the first preset value.

[0071] The real-time comprehensive quantity Q being greater than the comprehensive quantity threshold Q1, and the sealing compression quantity C being greater than or equal to the first compression quantity limit C1 and less than the second compression quantity limit C2, can indicate that there is a problem with the assembly state between the front wear plate 1003 and the impeller 1002, and there is also a problem with the compression state of the mechanical seal 1005. The embodiment of the present application can drive the rotor part such as the first bearing 1006 and the impeller 1002 to move towards the pump body 1001 through the second adjusting top screw 1008, so as to reduce the axial gap between the front wear plate 1003 and the impeller 1002 by the first preset value.

[0072] It is worth noting that when the rotor moves towards the pump body 1001, the dynamic ring of the mechanical seal 1005 moves forward with the rotor, which will push the static ring in the opposite direction, resulting in a decrease in the compression quantity of the elastic element (spring elongation or bellows relaxation). There can be a quantitative linkage between the two: for every G decrease in the axial gap, the sealing compression quantity C decreases by r x G (where r is a proportional coefficient determined by the structural parameters of the mechanical seal 1005, such as the stiffness of the elastic element, the axial distance between the dynamic ring and the static ring, etc.).

[0073] By detecting the deformation state of the elastic element in the mechanical seal 1005 (such as the length change of the spring or the expansion of the bellows), or directly measuring the change in the contact pressure of the dynamic ring and the static ring, the decrease in the sealing compression quantity C can be reflected. Therefore, when the sealing compression quantity C is too large, the compression state can be improved by adjusting the relationship between the rotor and the pump body 1001.

[0074] For example, the first preset value can be equal to 0.1 mm or 0.2 mm, which is not limited in the embodiment of the present application.

[0075] Further, the PLC 2003 can also be configured to perform the following step S308.

[0076] S308: In the case that the sealing compression amount C is greater than or equal to the second compression amount limit C2, a fifth control instruction is generated based on a second preset value, and the fifth control instruction is sent to the second driving module 2005 to drive the second adjusting top screw 1008, so as to reduce the axial gap 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.

[0077] The sealing compression amount C being greater than or equal to the second compression amount limit C2 indicates that there is a serious problem with the compression state of the mechanical seal 1005, and adjustment needs to be made regardless of whether there is a problem with the assembly state between the front wear plate 1003 and the impeller 1002. Therefore, in the case that the sealing compression amount C is greater than or equal to the second compression amount limit C2, the second adjusting top screw 1008 can be driven to reduce the axial gap between the front wear plate 1003 and the impeller 1002 by the second preset value.

[0078] 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, which is not limited in the embodiments of the present application.

[0079] It should be noted that when the sealing compression amount C ∈ [C1, C2), the axial gap is reduced by the first preset value to reduce the sealing compression amount C to [C3, C1) (normal range), so as to avoid excessive compression of the seal leading to accelerated wear; when the sealing compression amount C ≥ C2, the axial gap is adjusted by a larger second preset value to quickly reduce the sealing compression amount C to a safe range to prevent the elastic element from failing due to overpressure.

[0080] It should be noted that driving the first adjusting top screw 1004 to reduce the axial gap between the front wear plate 1003 and the impeller 1002 will hardly change the sealing compression amount C, and therefore is suitable for the case that the sealing compression amount C is within the normal range. Correspondingly, driving the second adjusting top screw 1008 to reduce the axial gap between the front wear plate 1003 and the impeller 1002 will drive the first bearing 1006 and the impeller 1002 to move towards the pump body 1001, thereby synchronously moving the dynamic ring of the mechanical seal 1005 axially, so as to change the compression degree of the elastic element and reduce the sealing compression amount C. Therefore, the adjusting method is suitable for the case that the sealing compression amount C exceeds the normal range (i.e. C ≥ C1), and can synchronously correct the sealing compression amount C by adjusting the axial gap, so as to ensure that the sealing state and the gap state are in a reasonable range.

[0081] Further, the PLC 2003 can also be configured to perform the following steps S3031-S3035.

[0082] S3031: Collect the real-time working condition of the chemical process pump according to the second preset frequency, and the real-time working condition includes a real-time rotating speed, a pump body outlet pressure, a conveying medium temperature, a motor output power and / or a bearing temperature.

[0083] The real-time rotating speed can be a real-time rotating speed fed back by the chemical process pump. The pump outlet pressure can be measured by a pressure sensor at the outlet of the pump body 1001. The input medium temperature can be measured by a medium temperature sensor. The motor output power can be determined by a power analyzer of the motor of the chemical process pump. The bearing temperature can be measured by a temperature sensor of the first bearing 1006.

[0084] S3032: Determine a plurality of historical curves matched with the real-time working condition.

[0085] In the embodiments of the present application, a vector corresponding to the real-time working condition can be constructed. Then, the Euclidean distance between the real-time working condition vector and each historical working condition vector in the historical working condition library is calculated, and the historical curve corresponding to the historical working condition vector with an Euclidean distance less than a distance threshold is determined as a historical curve matched with the real-time working condition. It can be understood that there can be a plurality of historical curves, and the plurality of historical curves include a plurality of historical gap curves and a plurality of historical compression amount curves.

[0086] 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 the first gaps G1.

[0087] The first gap curve and the second gap curve are curves of the first gap G1 changing with time. Time can be the horizontal coordinate, and the first gap G1 can be the vertical coordinate.

[0088] It can be understood that all the first gaps G1 include the first gap G1 collected each time.

[0089] S3034: Generate a first sealing compression amount curve based on the sealing compression amount C collected N times before the current time, and generate a second sealing compression amount curve based on all the sealing compression amounts C.

[0090] The sealing compression amount curve is a curve of the sealing compression amount C changing with time. Time can be the horizontal coordinate, and the sealing compression amount C can be the vertical coordinate.

[0091] It can be understood that all the sealing compression amounts C include the sealing compression amount C collected each time.

[0092] S3035: Input the plurality of historical curves, the first gap curve, the second gap curve, the first sealing compression amount curve and the second sealing compression amount curve into the first prediction model to determine the first adjustment time and the second adjustment time.

[0093] Further, the PLC 2003 can also be configured to perform the following steps S30351-S30354.

[0094] S30351: determining a historical gap curve matching the second gap curve based on a first prediction model.

[0095] Specifically, the first prediction model can be a hybrid model that combines feature engineering and machine learning. The core function of the hybrid model is to achieve curve matching through multi-dimensional feature comparison, and ultimately determine a unique historical gap curve that best matches the second gap curve among multiple historical gap curves, thereby achieving secondary screening.

[0096] S30352: determining a first curve segment in the matching historical gap curve; wherein the first curve segment has a trend similarity to the first gap curve greater than a similarity threshold.

[0097] In the embodiments of the present application, 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 multiplied by N. For example, when the second preset frequency is 5 min / time and N is equal to 10, the time window can be equal to 50 min.

[0098] Then, the embodiments of the present application can calculate the trend similarity of the first gap curve to each curve segment. Specifically, the embodiments of the present application can use algorithms such as dynamic time warping (DTW), correlation coefficient, or least squares method to calculate the similarity of the first gap curve to each curve segment, thereby obtaining the trend similarity of the first gap curve to each curve segment. Further, the curve segment with a trend similarity greater than a similarity threshold is taken as the first curve segment. It is worth noting that when the curve segments with a trend similarity greater than the similarity threshold are not unique, the curve segment with the maximum trend similarity can be taken as the first curve segment.

[0099] S30353: determining a first target point in the historical gap curve along the time direction in the first curve segment, wherein the vertical coordinate corresponding to the first target point corresponds to the most recently collected first gap G1.

[0100] In the embodiments of the present application, the first fitting slope of the tail section of the first gap curve can be calculated, wherein the tail section refers to a section before the first gap G1, and the length of the vertical coordinate corresponding to the tail section is equal to a preset value. Further, the first curve segment is divided into multiple sub-segments, and the length of the vertical coordinate corresponding to each sub-segment is also equal to the preset value. Then, the second fitting slope of each sub-segment is calculated, the second fitting slope closest to the first fitting slope is determined, the sub-segment corresponding to the second fitting slope closest to the first fitting slope is determined as the first target sub-segment corresponding to the tail section, and the end point of the first target sub-segment is determined as the first target point.

[0101] S30354: Determine the first adjustment time based on the horizontal coordinate corresponding to the first target point.

[0102] Embodiments of the present application can traverse each sub-segment after the first target sub-segment, determine the first sub-segment with a fitting slope difference greater than a preset slope threshold as the second target sub-segment.

[0103] Further, the end point or the vertical coordinate intermediate point on the second target sub-segment is determined as the third target point. And the horizontal coordinate difference between the third target point and the first target point is calculated to obtain a second difference value. And embodiments of the present application can obtain the time stamp of the current time after calculating the second difference value, and sum the current time stamp and the second difference value to obtain the first adjustment time.

[0104] In some implementations, if the first target sub-segment is the last one of all sub-segments, the time stamp of the current time can be obtained, and the current time stamp and a preset time difference value are summed to obtain the first adjustment time. For example, the preset time difference value can be equal to 5 min, 10 min or 15 min, which is not limited by embodiments of the present application.

[0105] In this way, the first adjustment time can be determined.

[0106] And the PLC 2003 can also be configured to perform the following steps S30355-S30358.

[0107] S30355: Determine a historical compression amount curve matching the second sealing compression amount curve based on the first prediction model.

[0108] S30356: Determine a second curve segment in the matching historical compression amount curve; wherein the similarity of the trend of the second curve segment to the first sealing compression amount curve is greater than a similarity threshold.

[0109] In embodiments of the present application, for the historical compression amount curve matching the second sealing compression amount curve, it 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 x N. For example, when the second preset frequency is 5 min / time and N is equal to 10, the time window can be equal to 50 min.

[0110] Afterwards, the embodiment of the present application can calculate the trend similarity of the first sealing compression amount curve and each curve segment. Specifically, the embodiment of the present application can use dynamic time warping (DTW), correlation coefficient, least square method or other algorithms to calculate the similarity of the first sealing compression amount curve and each curve segment, and obtain the trend similarity of the first sealing compression amount curve and each curve segment. Further, the curve segment with a trend similarity greater than a similarity threshold is taken as a second curve segment. It should be noted that when the curve segment with a trend similarity greater than a similarity threshold is not unique, the curve segment with the maximum trend similarity can be taken as the second curve segment.

[0111] S30357: In the historical compression amount curve, a second target point located in the second curve segment is determined in the time direction, wherein the ordinate corresponding to the second target point corresponds to the sealing compression amount C collected last time.

[0112] In the embodiment of the present application, a third fitting slope of the tail section of the first sealing compression amount curve can be calculated, wherein the tail section refers to a section before the sealing compression amount C, and the length of the ordinate corresponding to the tail section is equal to a preset value. Further, the second curve segment is divided into a plurality of sub-segments, and the length of the ordinate corresponding to each sub-segment is also equal to the preset value. Then, the fourth fitting slope of each sub-segment is calculated, the fourth fitting slope closest to the third fitting slope is determined, and the sub-segment corresponding to the fourth fitting slope closest to the third fitting slope is determined as the second target sub-segment corresponding to the tail section, and the tail point of the second target sub-segment is determined as the second target point.

[0113] S30358: The second adjustment time is determined based on the abscissa corresponding to the second target point.

[0114] The embodiment of the present application can traverse each sub-segment after the second target sub-segment, and determine the first sub-segment with a fitting slope difference greater than a preset slope threshold from the fitting slope of the second target sub-segment, and determine the first sub-segment as the second target sub-segment.

[0115] Further, the tail point or the ordinate middle point on the second target sub-segment is determined as a fourth target point. Further, the abscissa difference between the fourth target point and the second target point is calculated to obtain a third difference value. Further, the embodiment of the present application can obtain the time stamp of the current time after calculating the third difference value, and sum the current time stamp and the third difference value to obtain the second adjustment time. In some implementations, if the second target sub-segment is the last one of all sub-segments, the time stamp of the current time can be obtained, and the current time stamp and a preset time difference value are summed to obtain the second adjustment time.

[0116] In the embodiments of the present application, the specific execution logic of steps S30355-S30358 can refer to the step description of the preceding S30351-S30354, which will not be described here.

[0117] Further, the PLC 2003 can also be configured to perform the following steps S401-S403.

[0118] S401: Collect the second adjustment time determined M times before the current time according to a third preset frequency; wherein the value of M is pre-set.

[0119] For example, the third preset frequency is, for example, once every hour, and M can be equal to 5, 10 or 15, which is not limited in the embodiments of the present application. In actual application, the parameters can be dynamically adjusted according to the aging characteristics of the mechanical seal 1005: for high-loss working conditions (such as high-temperature and high-pressure environment), the third preset frequency can be shortened to once every 30 minutes, and M=15 to retain more historical data; for low-loss working conditions, the frequency can be maintained once every hour, and M=5 can meet the prediction requirements. During the collection process, the working condition parameters (such as medium temperature and operating pressure) corresponding to each second adjustment time need to be recorded synchronously, and abnormal adjustment times (such as values deviating from the normal range by more than 3 times) caused by sudden failures need to be excluded to ensure the effectiveness of the input data.

[0120] S402: Input the second adjustment time determined M times before the current time into the second prediction model, and predict the aging time of the mechanical seal 1005 by using the second prediction model.

[0121] The second prediction model can be a time series prediction model based on a long short-term memory network (LSTM), which realizes prediction by learning the trend of the second adjustment time (such as the rule of gradually shortening with the aging degree). For example, the second prediction model can first normalize the M second adjustment times to convert them into sequence data in the interval [0, 1]; then extract the features of the M second adjustment times through a sliding window to capture the dependency of the time series; finally, output the trend of the future adjustment time through a multi-layer LSTM network, and calculate the aging time (i.e. the time point when the adjustment time shortens to the preset failure threshold) of the mechanical seal 1005.

[0122] S403: Generate a first alarm information at a target time point, the target time point being located before the aging time and having a preset time interval from the aging time.

[0123] In this way, through the complete process of continuously collecting historical adjustment times, using a time series model to predict the trend, and triggering an alarm in advance, the aging time of the mechanical seal 1005 can be accurately predicted and early warning can be realized, reducing the production interruption caused by sudden failure.

[0124] Further, the PLC 2003 can be further configured to perform the following step S501: generating first alarm information in a case that the first adjustment time or the second adjustment time is less than a first time threshold.

[0125] It can be understood that if the first adjustment time is less than the first time threshold, it can indicate that the current first gap G1 is growing at an abnormally fast speed, and timely alarm should be given. If the second adjustment time is less than the first time threshold, it can indicate that the sealing performance of the mechanical seal 1005 is rapidly deteriorating, and alarm is also needed. Exemplarily, the first time threshold can be equal to 30 min, and the embodiments of the present application do not make specific limitation thereto.

[0126] And / or, the PLC 2003 can be further configured to perform the following step S502: generating second alarm information in a case that a time difference between two adjacent first adjustment times is less than a second time threshold.

[0127] The second time threshold can be less than the first time threshold, and exemplarily, the second time threshold can be 10 min. It can be understood that if the two adjacent adjustment times are too close, it can indicate that the gap growth speed is abnormal, and timely alarm should be given.

[0128] And / or, the PLC 2003 can be further configured to perform the following step S503: generating third alarm information in a case that a time difference between two adjacent second adjustment times is less than a third time threshold.

[0129] The third time threshold can be less than the first time threshold, and exemplarily, the third time threshold can be 10 min. It can be understood that if the two adjacent adjustment times are too close, it can indicate that the sealing state of the mechanical seal 1005 changes too fast, and timely alarm should be given.

[0130] Further, the PLC 2003 can be further configured to perform the following step S601: generating fourth alarm information in a case that the first difference D1 is greater than a difference threshold.

[0131] Exemplarily, the difference threshold can be equal to 1 mm, and when the first difference D1 is greater than the difference threshold, it can be determined that the gap is too large, and timely alarm should be given.

[0132] From the above, the automatic control system of the chemical process pump provided by the embodiment of the present application can solve the drawbacks of traditional shutdown maintenance and ensure production continuity. Without shutdown, the system can collect key parameters in real time through the gap detection module 2001 and the compression amount detection module 2002 and intelligently analyze the parameters by the PLC 2003; the system can dynamically adjust the gap and the sealing state, predict the adjustment time in combination with the first prediction model, realize collaborative and accurate control of the gap and the sealing, and reduce manual errors; the system can also predict the aging time of the mechanical seal 1005 by means of the second prediction model, generate multiple levels of alarms according to the adjustment time, the difference and other abnormalities, and avoid risks such as leakage in advance; and the system can adapt to different working conditions to adjust parameters, ensure the efficiency of the pump body and the reliability of the sealing, and reduce production interruption losses.

[0133] Figure 4 The flowchart of the automatic control method of the chemical process pump provided by the embodiment of the present application is shown.

[0134] The embodiment of the present application also provides an automatic control method of a chemical process pump, which can be applied to the aforementioned chemical process pump. The method comprises the following steps S701-S704.

[0135] S701: In response to a first control instruction, the first gap G1 between the impeller and the front wear plate is collected;

[0136] S702: In response to a second control instruction, the compression amount of the mechanical seal is collected to obtain the sealing compression amount C; the sealing compression amount is directly proportional to the compression degree of the elastic element of the mechanical seal;

[0137] S703: According to a first preset frequency, the real-time comprehensive amount Q is generated based on the last collected first gap G1 and the last collected sealing compression amount C; and according to the first preset frequency, the first difference D1 between the first gap G1 and the standard gap G is calculated;

[0138] S704: In the case that the real-time comprehensive amount Q is greater than the comprehensive amount threshold Q1 and the sealing compression amount C is less than the first compression amount limit C1, the third control instruction is generated based on the first difference D1, and the third control instruction is issued to the first driving module to drive the first adjustment top screw, so as to reduce the axial gap between the front wear plate and the impeller by the first difference D1;

[0139] In addition, the method further comprises the following steps S705-S707.

[0140] S705: According to a second preset frequency, the first gap G1 and the sealing compression amount 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 are the same or different;

[0141] S706: generating a new first control instruction when the first adjustment time arrives;

[0142] S707: generating a new second control instruction when the second adjustment time arrives.

[0143] In an implementation manner, after the step S703, the method can further include the following step S708: in a case that 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, generating a fourth control instruction based on the first preset value, and issuing the fourth control instruction to the second driving module, so as to drive the second driving module to drive the second adjustment top screw, thereby reducing the axial gap between the front wear plate and the impeller by the first preset value.

[0144] In an implementation manner, after the step S703, the method can further include the following step S709: in a case that the sealing compression quantity C is greater than or equal to the second compression quantity limit C2, generating a fifth control instruction based on the second preset value, and issuing the fifth control instruction to the second driving module, so as to drive the second driving module to drive the second adjustment top screw, thereby reducing the axial gap 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.

[0145] In an implementation manner, the step S705 can include the following steps S7051-S7055.

[0146] S7051: collecting the real-time working condition of the chemical process pump according to the second preset frequency, the real-time working condition including the real-time rotating speed, the pump body outlet pressure, the conveying medium temperature, the motor output power and / or the bearing temperature;

[0147] S7052: determining a plurality of historical curves matched with the real-time working condition;

[0148] S7053: generating a first gap curve based on the first gap G1 collected N times before the current time, and generating a second gap curve based on all the first gaps G1, the first gap curve and the second gap curve being curves of the first gap G1 changing with time;

[0149] S7054: and generating a first sealing compression quantity curve based on the sealing compression quantity C collected N times before the current time, and generating a second sealing compression quantity curve based on all the sealing compression quantities C, the first sealing compression quantity curve and the second sealing compression quantity curve being curves of the sealing compression quantity C changing with time;

[0150] S7055: inputting the plurality of historical curves, the first gap curve, the second gap curve, the first sealing compression quantity curve and the second sealing compression quantity curve into the first prediction model, and determining the first adjustment time and the second adjustment time.

[0151] In an implementation manner, the plurality of historical curves comprises a plurality of historical gap curves and a plurality of historical compression amount curves; and step S7055 can comprise steps S70551-S70554.

[0152] S70551: determining a historical gap curve matching the second gap curve based on the first prediction model;

[0153] S70552: determining a first curve segment in the matching historical gap curve; wherein the first curve segment has a similarity greater than a similarity threshold with a trend of the first gap curve;

[0154] S70553: determining a first target point in the historical gap curve in a time direction and located in the first curve segment, wherein the first target point corresponds to a latest collected first gap G1;

[0155] S70554: determining the first adjustment time based on an abscissa corresponding to the first target point;

[0156] And, step S7055 can further comprise steps S70555-S70558.

[0157] S70555: determining a historical compression amount curve matching the second seal compression amount curve based on the first prediction model;

[0158] S70556: determining a second curve segment in the matching historical compression amount curve; wherein the second curve segment has a similarity greater than a similarity threshold with a trend of the first seal compression amount curve;

[0159] S70557: determining a second target point in the historical compression amount curve in a time direction and located in the second curve segment, wherein the second target point corresponds to a latest collected seal compression amount C;

[0160] S70558: determining the second adjustment time based on an abscissa corresponding to the second target point.

[0161] In an implementation manner, the method can further comprise steps S801-S803.

[0162] S801: collecting the second adjustment time determined for M times before the current time according to a third preset frequency; wherein the value of M is preset;

[0163] S802: inputting the second adjustment time determined for M times before the current time into the second prediction model, and predicting the aging time of the mechanical seal by using the second prediction model;

[0164] S803: generate the first alarm information at a target time point, the target time point being located before the aging time and having a preset time length interval with the aging time.

[0165] In an implementation manner, the method can further include the following step S804: generating the first alarm information in a case that the first adjustment time or the second adjustment time is less than the first time threshold;

[0166] and / or, further include the following step S805: generating the second alarm information in a case that a time difference between two adjacent first adjustment times is less than a second time threshold;

[0167] and / or, further include the following step S806: generating the third alarm information in a case that a time difference between two adjacent second adjustment times is less than a third time threshold.

[0168] In an implementation manner, the method can further include the following step S807: generating fourth alarm information in a case that the first difference D1 is greater than a difference threshold.

[0169] Figure 5 A structural schematic diagram of an electronic device provided by an embodiment of the present application.

[0170] As shown in Figure 5 The present application provides an electronic device, which includes a processor 10 and a memory 20, the memory 20 storing a computer program, and the processor 10 is configured to run the computer program to execute the steps in any of the embodiments of the automatic control method of the chemical process pump.

[0171] In a specific implementation, the present application further provides a computer storage medium, which can store a program, and the program can include some or all steps in the embodiments of the automatic control method of the chemical process pump provided by the present application when executed. The storage medium can be a magnetic disc, an optical disc, a read-only memory (ROM) or a random access memory (RAM), etc.

[0172] It is easy to understand that, based on the several embodiments provided by the present application, a person skilled in the art can combine, split, recombine, etc. the embodiments of the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0173] The above detailed description of the embodiments of the present application is merely intended to provide a further detailed description of the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above is only a specific implementation of the embodiments of the present application, and is not used to limit the protection scope of the embodiments of the present application. Any modification, equivalent replacement, improvement, etc. made on the basis of the technical solutions of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. An automatic control system for a chemical process pump, characterized by, The application is applied to a chemical process pump, and the chemical process pump at least comprises a pump body, an impeller, a front wear plate, a first adjusting top screw and a mechanical seal, the pump body and the impeller are arranged in axial opposition, the front wear plate is arranged in the pump body and in axial opposition with the impeller, the first adjusting top screw passes through the pump body in the axial direction and abuts against the front wear plate, and is used for driving the front wear plate to move relative to the impeller to reduce the axial gap between the front wear plate and the impeller; the mechanical seal comprises an elastic element, which is used for providing axial sealing for the chemical process pump through axial elastic deformation. The system comprises: A gap detection module configured to collect a first gap G1 between the impeller and the front wear plate in response to a first control instruction; A compression amount detection module configured to collect a compression amount of the mechanical seal in response to a second control instruction to obtain a sealing compression amount C; the sealing compression amount C is directly proportional to the compression degree of the elastic element of the mechanical seal; A programmable logic controller (PLC) configured to generate a real-time comprehensive amount Q based on the last collected first gap G1 and the last collected sealing compression amount C at a first preset frequency, and calculate a first difference D1 between the first gap G1 and a standard gap G at the first preset frequency; In the case that the real-time comprehensive amount Q is greater than a comprehensive amount threshold Q1 and the sealing compression amount C is less than a first compression amount limit C1, a third control instruction is generated based on the first difference D1, and the third control instruction is issued to the first driving module to drive the first adjusting top screw, thereby reducing the axial gap between the front wear plate and the impeller by the first difference D1; And the PLC is further configured to input the first gap G1 and the sealing compression amount C collected N times before the current time into a first prediction model at a second preset frequency, and predict a first adjustment time and a second adjustment time by using the first prediction model; the first adjustment time and the second adjustment time are the same or different; When the first adjustment time comes, a new first control instruction is generated and issued to the gap detection module; When the second adjustment time comes, a new second control instruction is generated and issued to the compression amount detection module.

2. The automatic control system of a chemical process pump according to claim 1, characterized in that, The chemical process pump further comprises a first bearing, a rear bearing cover and a second adjusting top screw, the first bearing is connected to the impeller in the axial direction, the rear bearing cover is located on the side of the first bearing away from the impeller, and the second adjusting top screw passes through the rear bearing cover in the axial direction and abuts against the first bearing, and the second adjusting top screw is used for driving the first bearing and the impeller to move towards the pump body to reduce the axial gap between the front wear plate and the impeller; The PLC is further configured to: In a case that 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 instruction is generated based on a first preset value, and the fourth control instruction is sent to the second driving module to drive the second driving module to drive the second adjusting top screw, thereby reducing the axial gap between the front wear plate and the impeller by the first preset value.

3. The automatic control system of a chemical process pump according to claim 2, wherein The PLC is further configured to: In a case that the sealing compression quantity C is greater than or equal to the second compression quantity limit C2, a fifth control instruction is generated based on a second preset value, and the fifth control instruction is sent to the second driving module to drive the second driving module to drive the second adjusting top screw, thereby reducing the axial gap 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.

4. The automatic control system of a chemical process pump according to claim 1, wherein The PLC is further configured to: According to the second preset frequency, the real-time working conditions of the chemical process pump are collected, and the real-time working conditions include a real-time rotating speed, a pump body outlet pressure, a conveying medium temperature, a motor output power and / or a bearing temperature; A plurality of historical curves matched with the real-time working conditions are determined; A first gap curve is generated based on the first gap G1 collected N times before the current time, and a second gap curve is generated based on all the first gaps G1, the first gap curve and the second gap curve being curves of the first gap G1 changing with time; And the PLC is further configured to: A first sealing compression quantity curve is generated based on the sealing compression quantity C collected N times before the current time, and a second sealing compression quantity curve is generated based on all the sealing compression quantities C, the first sealing compression quantity curve and the second sealing compression quantity curve being curves of the sealing compression quantity C changing with time; The plurality of historical curves, the first gap curve, the second gap curve, the first sealing compression quantity curve and the second sealing compression quantity curve are input into the first prediction model to determine the first adjusting time and the second adjusting time.

5. The automatic control system of a chemical process pump according to claim 4, wherein The plurality of historical curves include a plurality of historical gap curves and a plurality of historical compression quantity curves; the PLC is further configured to: The historical gap curve matched with the second gap curve is determined based on the first prediction model; A first curve segment is determined in the matched historical gap curve; wherein a similarity degree of the first curve segment and the first gap curve is greater than a similarity threshold; A first target point located in the first curve segment is determined in the historical gap curve in a time direction, wherein a longitudinal coordinate corresponding to the first target point corresponds to the first gap G1 collected most recently; The first adjusting time is determined based on a horizontal coordinate corresponding to the first target point; And the PLC is further configured to: The historical compression quantity curve matched with the second sealing compression quantity curve is determined based on the first prediction model; determining a second curve segment in the historical compression amount curve along a time direction, wherein the second curve segment is similar to the first sealing compression amount curve, and a similarity degree of the second curve segment to the first sealing compression amount curve is greater than the similarity threshold; determining a second target point in the second curve segment in the historical compression amount curve along the time direction, wherein a longitudinal coordinate corresponding to the second target point corresponds to the sealing compression amount C collected at a latest time; determining the second adjustment time based on a horizontal coordinate corresponding to the second target point.

6. The automatic control system of a chemical process pump according to claim 1, wherein The PLC is further configured to: collect the second adjustment time determined at M times before a current time according to a third preset frequency, wherein a value of M is preset; input the second adjustment time determined at M times before the current time into a second prediction model, and predict an aging time of the mechanical seal by using the second prediction model; generate first alarm information at a target time point, wherein the target time point is located before the aging time and has a preset time interval from the aging time.

7. The automatic control system of a chemical process pump according to claim 1, wherein The PLC is further configured to: generate first alarm information in a case that the first adjustment time or the second adjustment time is less than a first time threshold; and / or, generate second alarm information in a case that a time difference between adjacent two first adjustment times is less than a second time threshold; and / or, generate third alarm information in a case that a time difference between adjacent two second adjustment times is less than a third time threshold.

8. The automatic control system of a chemical process pump according to claim 1, wherein The PLC is further configured to: generate fourth alarm information in a case that the first difference D1 is greater than a difference threshold.

9. An automatic control method of a chemical process pump, characterized by, The chemical process pump at least comprises a pump body, an impeller, a front wear plate, a first adjustment top screw, and a mechanical seal. The pump body and the impeller are arranged in an axial direction. The front wear plate is arranged in the pump body and in an axial direction opposite to the impeller. The first adjustment top screw passes through the pump body in an axial direction and abuts against the front wear plate, and is used to drive the front wear plate to move relative to the impeller to reduce an axial gap between the front wear plate and the impeller. The mechanical seal comprises an elastic element, which is used to provide axial sealing for the chemical process pump through axial elastic deformation. The method comprises: collecting a first gap G1 between the impeller and the front wear plate in response to a first control instruction; collecting a sealing compression amount C of the mechanical seal in response to a second control instruction, wherein the sealing compression amount C is proportional to a compression degree of the elastic element of the mechanical seal; generating a real-time comprehensive amount Q based on the first gap G1 collected at a latest time and the sealing compression amount C collected at a latest time according to a first preset frequency, and calculating a first difference D1 between the first gap G1 and a standard gap G according to the first preset frequency; In a case where the real-time comprehensive quantity Q is greater than a comprehensive quantity threshold Q1 and the sealing compression quantity C is less than a first compression quantity limit C1, a third control instruction is generated based on the first difference D1, and the third control instruction is issued to the first driving module to drive the first adjusting top screw, thereby reducing the axial gap between the front wear plate and the impeller by the first difference D1. Furthermore, the method further comprises: inputting the first gap G1 and the sealing compression quantity C collected for N times before the current time into a first prediction model according to a second preset frequency, and predicting a first adjusting time and a second adjusting time by using the first prediction model; the first adjusting time is the same as or different from the second adjusting time; When the first adjusting time arrives, a new first control instruction is generated; When the second adjusting time arrives, a new second control instruction is generated.

10. An electronic device, comprising: Comprise: One or more processors; And A memory 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 of the chemical process pump according to claim 9.

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