Multi-stage centrifugal pump and monitoring system

Abstract

The invention provides a multistage centrifugal pump and a monitoring system, and relates to the technical field of multistage centrifugal pumps, the multistage centrifugal pump comprises a pump shaft, the non-driving end of the pump shaft is provided with a pair of single-row angular contact ball bearings, the pump shaft is provided with a first-stage impeller, an impeller and a last-stage impeller, the end face of the last-stage impeller is provided with a sealing ring, and a discharge section bushing ring is arranged in a discharge section. An original balance mechanism is omitted on the basis of an existing common multi-stage centrifugal pump, a sealing cavity is formed in the end face of a sealing ring and the end face of a discharging section bushing ring installed on a discharging section, and the sealing cavity is communicated with a suction cavity through a discharging section rear cavity. Meanwhile, a pair of single-row angular contact ball bearings is additionally arranged on the outer side of a cylindrical roller bearing at the non-driving end, after the pump is started, axial force which is generated by front N-1 stages of impellers and points to the driving end is balanced by axial force which is generated by a final-stage impeller and points to the non-driving end due to the fact that a sealing ring is arranged on the back face, and residual axial force is borne by the pair of single-row angular contact ball bearings; therefore, abrasion is reduced, and the service life of the pump is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of multi-stage centrifugal pumps, and in particular relates to a multi-stage centrifugal pump and a monitoring system. Background Art

[0002] The existing multi-stage centrifugal pump is generally a segmental multi-stage centrifugal pump with a single suction or double suction inlet. The suction port of the pump is arranged horizontally and the discharge port is arranged vertically upward. Its main components include: suction section, middle section, discharge section, stuffing box body, impeller (including first-stage impeller), guide vane (including last-stage guide vane), balance plate, balance ring, balance sleeve, shaft, bearing body, bearing, coupling, etc. The axial force generated when the pump is working is balanced by the balance mechanism (balance plate, balance ring, balance sleeve);

[0003] Its main disadvantage is the lack of axial force balancing components. The balancing disc, balancing ring and balancing sleeve are easily worn parts and need to be replaced when they are worn to a certain extent. However, replacement is often difficult. At the same time, after the balancing disc and balancing ring are worn, the rotor moves toward the drive end, and the impeller and guide vane flow channel are not aligned. If they are not replaced in time, it will lead to increased internal losses, reduced flow rate and reduced pump efficiency. Summary of the invention

[0004] The present invention provides a multi-stage centrifugal pump and a monitoring system to solve at least one of the above-mentioned technical problems.

[0005] In order to solve the above technical problems, the present invention discloses a multi-stage centrifugal pump, including a pump shaft, the driving end and the non-driving end of the pump shaft are both equipped with cylindrical roller bearings, the non-driving end of the pump shaft is equipped with a pair of single-row angular contact ball bearings, the pump shaft is provided with a first-stage impeller, an impeller and a last-stage impeller, the first-stage impeller, the impeller and the last-stage impeller are respectively located in the suction section, the middle section and the discharge section, a sealing ring is provided on the end face of the last-stage impeller, a discharge section liner ring is provided in the discharge section, a sealing cavity is formed between the end face of the sealing ring and the end face of the discharge section liner ring, and the sealing cavity is connected with the suction section through the rear cavity of the discharge section.

[0006] Preferably, the driving end of the pump shaft is equipped with a pump coupling and a shaft nut, the shaft nut is installed in the bearing body armor, the cylindrical roller bearing at the driving end of the pump shaft is installed in the bearing body armor, one end of the cylindrical roller bearing is provided with a perforated bearing end cover, and the other end face of the cylindrical roller bearing is provided with a bearing stop sleeve in sequence.

[0007] Preferably, a shaft sleeve, a packing gland and a packing ring are sequentially arranged on the suction section pump shaft;

[0008] A stuffing box body is provided after the discharge section, bearing body A is installed in front of the stuffing ring, and bearing body B is installed behind the stuffing box body;

[0009] A balancing water pipe assembly is arranged on the stuffing box body, and the balancing water pipe assembly is communicated with the suction section and the discharge section.

[0010] Preferably, the cylindrical roller bearing and angular contact ball bearing at the non-drive end of the pump shaft are both installed in bearing body B, a water retaining ring and a bearing spacer are installed at the non-drive end of the pump shaft, a gasket is installed at one end of the angular contact ball bearing, a bearing sleeve is provided outside the angular contact ball bearing, and a hole-free bearing end cover and a round nut are provided at the other end of the angular contact ball bearing.

[0011] Preferably, a first-stage sealing ring is provided on the end face of the first-stage impeller, a guide vane is provided outside the impeller, a guide vane sleeve is provided outside the guide vane, and a last-stage guide vane is provided outside the last-stage impeller.

[0012] Preferably, an anti-blocking and anti-wear component is installed at the suction section, and the anti-blocking and anti-wear component includes an L-shaped anti-blocking and anti-wear component shell, the input end of the L-shaped anti-blocking and anti-wear component shell is an inclined end face, and is provided with a filter screen 1, and the output end is bolted with a conical adapter, and the conical adapter is used to cooperate with the inner wall of the suction section. A large impurity collection chamber is provided in the L-shaped anti-blocking and anti-wear component shell, and a filter screen 2 is provided at the inlet of the large impurity collection chamber, and a scoop claw is rotatably connected to the rear of the filter screen 2;

[0013] A guide rod is fixedly connected in the large impurity collection chamber, and the guide rod is connected to a pressure plate by sliding up and down. The top of the pressure plate is connected to the inner wall of the large impurity collection chamber by an elastic part, and the bottom of the pressure plate is fixedly connected to a steel rope, and the other end of the steel rope is wound on an electric winding wheel. The large impurity collection chamber is rotatably connected to a linkage closing plate, and a negative pressure impeller is rotatably connected in the large impurity collection chamber. A drainage net is provided behind the negative pressure impeller, and an arc-shaped guide groove for fine sand is provided at a position relative to the drainage net on the inner wall of the L-shaped anti-blocking and anti-wear component shell, and a sand discharge auger is rotatably connected in the fine sand arc-shaped guide groove.

[0014] A multi-stage centrifugal pump monitoring system, comprising:

[0015] A data collection time determination module is used to determine a number of data collection times of the current monitoring period based on the current monitoring period;

[0016] The data collection module is used to collect data based on several data collection moments in the current monitoring cycle, including:

[0017] A flow acquisition unit for collecting flow rates of the suction section and the discharge section, a pressure acquisition unit for collecting pressures of the suction section and the discharge section, a vibration signal acquisition unit for collecting vibration signals of a multi-stage centrifugal pump, an ultrasonic signal acquisition unit for collecting ultrasonic signals of a multi-stage centrifugal pump, and a power acquisition unit for collecting power of a multi-stage centrifugal pump;

[0018] A performance evaluation value determination module is used to input the collection results of the flow collection unit, the pressure collection unit, the vibration signal collection unit, the ultrasonic signal collection unit and the power collection unit at several data collection moments into the trained multi-stage centrifugal pump delivery capacity evaluation model, the multi-stage centrifugal pump head capacity evaluation model, the multi-stage centrifugal pump mechanical state evaluation model, the multi-stage centrifugal pump sealing performance evaluation model and the multi-stage centrifugal pump energy efficiency evaluation model, respectively, to obtain the multi-stage centrifugal pump delivery capacity evaluation value, the multi-stage centrifugal pump head capacity evaluation value, the multi-stage centrifugal pump mechanical state evaluation value, the multi-stage centrifugal pump sealing performance evaluation value and the multi-stage centrifugal pump energy efficiency evaluation value at several data collection moments;

[0019] A monitoring matrix construction module, used to construct a monitoring matrix of a multi-stage centrifugal pump in the current monitoring period based on a number of data collection values ​​collected by the data collection module at a number of data collection moments in the current monitoring period and a number of evaluation values ​​obtained by the performance evaluation value determination module at a number of data collection moments in the current monitoring period;

[0020] The multi-stage centrifugal pump operation status analysis module is used to analyze the delivery capacity status, head capacity status, mechanical status, sealing performance status, and energy efficiency status of the multi-stage centrifugal pump based on the multi-stage centrifugal pump monitoring matrix in the current monitoring period, and to issue an emergency alarm prompt for the corresponding status performance based on the analysis results, or to predict the overall operation status evaluation value of the multi-stage centrifugal pump, and to issue an overall performance early warning prompt for the multi-stage centrifugal pump based on the prediction results.

[0021] Preferably, the monitoring matrix construction module constructs the monitoring matrix of the multi-stage centrifugal pump in the current monitoring period, including:

[0022] in, is the monitoring matrix of the multi-stage centrifugal pump in the i-th monitoring period, a i1 is the flow difference between the suction section and the discharge section collected by the flow collection unit at the first data collection moment of the i-th monitoring cycle, a i2 is the flow difference between the suction section and the discharge section collected by the flow collection unit at the second data collection moment of the i-th monitoring cycle, a in is the flow difference between the suction section and the discharge section collected by the flow collection unit at the nth data collection moment in the ith monitoring cycle, b i1 is the pressure difference between the suction section and the discharge section collected by the pressure collection unit at the first data collection moment of the i-th monitoring cycle, b i2 is the pressure difference between the suction section and the discharge section collected by the pressure collection unit at the second data collection moment in the i-th monitoring cycle, b in is the pressure difference between the suction section and the discharge section collected by the pressure collection unit at the nth data collection moment in the ith monitoring cycle, c i1is the vibration velocity collected by the vibration signal acquisition unit at the first data acquisition moment of the i-th monitoring cycle, c i2 is the vibration velocity collected by the vibration signal acquisition unit at the second data acquisition moment of the i-th monitoring cycle, c in is the vibration speed collected by the vibration signal collection unit at the nth data collection moment in the ith monitoring cycle, d i1 is the sound pressure level value collected by the ultrasonic signal acquisition unit at the first data acquisition moment of the i-th monitoring cycle, d i2 is the sound pressure level value collected by the ultrasonic signal acquisition unit at the second data acquisition moment in the i-th monitoring cycle, d in is the sound pressure level value collected by the ultrasonic signal acquisition unit at the nth data acquisition moment in the ith monitoring cycle, e i1 is the power value collected by the power collection unit at the first data collection moment in the i-th monitoring cycle, e i2 is the power value collected by the power collection unit at the second data collection moment in the i-th monitoring cycle, e in is the power value collected by the power collection unit at the nth data collection moment in the ith monitoring cycle, A i1 is the estimated value of the multi-stage centrifugal pump delivery capacity at the first data collection moment in the i-th monitoring period, A i2 is the estimated value of the multi-stage centrifugal pump delivery capacity at the second data collection moment in the i-th monitoring period, A in is the estimated value of the multi-stage centrifugal pump delivery capacity at the nth data collection moment in the ith monitoring period, B i1 is the head capacity evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring period, B i2 is the head capacity evaluation value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring period, B in is the head capacity evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring period, C i1 is the mechanical condition assessment value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring cycle, C i2 is the mechanical condition assessment value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring cycle, C in is the mechanical condition evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring cycle, D i1 is the sealing performance evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring cycle, D i2 is the sealing performance evaluation value of the multistage centrifugal pump at the second data collection moment in the ith monitoring cycle, D in is the sealing performance evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring cycle, E i1 is the energy efficiency evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring period, E i2is the energy efficiency evaluation value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring cycle, E in It is the energy efficiency evaluation value of the multi-stage centrifugal pump at the nth data collection moment in the ith monitoring cycle.

[0023] Preferably, the multi-stage centrifugal pump operation status analysis module includes:

[0024] The traversal analysis unit is used to obtain the delivery capacity state matrix, head capacity state matrix, mechanical state matrix, sealing performance state matrix and energy efficiency state matrix of the multistage centrifugal pump in the current monitoring period based on the multistage centrifugal pump monitoring matrix in the current monitoring period:

[0025] Delete the collected values ​​of the flow collection unit and the multi-stage centrifugal pump delivery capacity evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period, and obtain the delivery capacity state matrix of the multi-stage centrifugal pump in the current monitoring period;

[0026] Delete the collected values ​​of the pressure collection unit and the head capacity evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the head capacity state matrix of the multistage centrifugal pump in the current monitoring period;

[0027] Delete the collected values ​​of the vibration signal collection unit and the mechanical state evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the mechanical state matrix of the multistage centrifugal pump in the current monitoring period;

[0028] Delete the collected values ​​of the ultrasonic signal collection unit and the sealing performance evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the sealing performance status matrix of the multistage centrifugal pump in the current monitoring period;

[0029] Delete the collected values ​​of the power collection unit and the energy efficiency evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the energy efficiency state matrix of the multistage centrifugal pump in the current monitoring period;

[0030] The alarm judgment unit compares the ranks of the conveying capacity state matrix, the lift capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix with the benchmark evaluation values ​​of the corresponding states. If the ranks of the conveying capacity state matrix, the lift capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix are greater than the benchmark evaluation values ​​of the corresponding states, the corresponding states are unqualified, and an emergency alarm prompt for the corresponding state performance is issued. Otherwise, the overall operation state evaluation value of the multi-stage centrifugal pump is predicted;

[0031] The overall operation status evaluation value prediction unit is used to predict the overall operation status evaluation value of the multi-stage centrifugal pump in the next monitoring cycle, and determine whether to issue an overall performance early warning prompt for the multi-stage centrifugal pump based on the prediction result.

[0032] Preferably, the overall operation status evaluation value prediction unit includes:

[0033] The overall operation status evaluation value determination subunit of the multistage centrifugal pump is used to calculate the rank of the monitoring matrix of the multistage centrifugal pump in the current monitoring period as the overall operation status evaluation value of the multistage centrifugal pump in the current monitoring period;

[0034] The overall operation status evaluation value prediction matrix construction subunit of the multistage centrifugal pump is used to construct the overall operation status evaluation value prediction matrix of the multistage centrifugal pump based on the overall operation status evaluation values ​​of the multistage centrifugal pump in several monitoring periods:

[0035] Among them, W i is the prediction matrix of the overall operating status evaluation value of the multistage centrifugal pump in the i-th monitoring period, w 1 is the overall operating status evaluation value of the multistage centrifugal pump in the first monitoring cycle, w 2 is the overall operating status evaluation value of the multistage centrifugal pump in the second monitoring cycle, w 3 is the overall operating status evaluation value of the multistage centrifugal pump in the third monitoring cycle, w i-1 is the overall operating status evaluation value of the multistage centrifugal pump in the i-1th monitoring period, w i is the overall operating status evaluation value of the multi-stage centrifugal pump in the i-th monitoring period;

[0036] The prediction value determination subunit obtains the mean value of all matrix elements in the third column of the prediction matrix of the overall operation status evaluation value of the multistage centrifugal pump in the i-th monitoring period, and replaces the values ​​of all matrix elements in the third row of the prediction matrix of the overall operation status evaluation value of the multistage centrifugal pump in the i-th monitoring period with the mean value of all matrix elements in the third column to obtain a new matrix, and uses the rank of the new matrix as the overall operation status evaluation value of the multistage centrifugal pump in the i+1-th monitoring period;

[0037] The early warning judgment unit issues an early warning prompt if the overall operating status evaluation value of the multi-stage centrifugal pump in the (i+1)th monitoring period is less than a preset overall operating status evaluation value of the multi-stage centrifugal pump.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention cancels the original balancing mechanism on the basis of the existing common segmented multi-stage centrifugal pump, arranges a sealing ring on the back of the last-stage impeller, forms a sealing cavity with the end face of the sealing ring and the end face of the discharge section liner ring installed on the discharge section, and the sealing cavity is connected with the suction cavity through the discharge section rear cavity, and at the same time, a pair of single-row angular contact ball bearings are additionally arranged on the outer side of the non-driving end cylindrical roller bearing. After the pump is started, the axial force directed to the driving end generated by the first N-1 stage impeller is balanced by the axial force directed to the non-driving end generated by the last-stage impeller due to the sealing ring arranged on the back, and the residual axial force is borne by the pair of single-row angular contact ball bearings, thereby reducing wear and extending the service life of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0041] Figure 1 It is a schematic diagram of the structure of the multi-stage centrifugal pump of the present invention.

[0042] Figure 2 It is a schematic diagram of the structure of the anti-blocking and anti-wear component of the present invention.

[0043] In the figure: 1, pump coupling; 2, pump shaft; 3, shaft nut; 4, bearing end cover with holes; 5, cylindrical roller bearing; 6, bearing stopper; 7, bearing body A; 8, shaft sleeve; 9, packing gland; 10, packing ring; 11, suction section; 12, first-stage sealing ring; 13, first-stage impeller; 14, guide vane; 15, middle section; 16, tie rod; 17, balance water pipe assembly; 18, impeller; 19, guide vane sleeve; 20, sealing ring; 21, final impeller; 22, final guide vane; 23, final impeller liner ring; 24, discharge section; 25, discharge section liner ring; 26, stuffing box body; 27, bearing body B; 28. Water retaining ring; 29. ​​Bearing spacer; 30. Gasket; 31. Bearing bushing; 32. Bearing body water seal cover; 33. Angular contact ball bearing; 34. Bearing end cover without hole; 35. Round nut; 36. Anti-blocking and anti-wear component; 37. L-type anti-blocking and anti-wear component shell; 38. Conical adapter; 39. Filter one; 40. Large impurity collection chamber; 41. Guide rod; 42. Pressure plate; 43. Steel rope; 44. Electric winding wheel; 45. Linkage closing plate; 46. Negative pressure impeller; 47. Drainage net; 48. Fine sand arc guide groove; 49. Sand removal auger; 50. Filter two; 51. Fishing claw. DETAILED DESCRIPTION

[0044] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0045] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] The present invention provides the following embodiments

[0047] Example 1

[0048] The embodiment of the present invention provides a multi-stage centrifugal pump and a monitoring system, such as Figure 1 As shown, it includes a pump shaft 2, the driving end and the non-driving end of the pump shaft 2 are both equipped with cylindrical roller bearings 5, the non-driving end of the pump shaft 2 is equipped with a pair of single-row angular contact ball bearings 33, and the pump shaft 2 is provided with a first-stage impeller 13, an impeller 18 and a final-stage impeller 21. The first-stage impeller 13, the impeller 18 and the final-stage impeller 21 are respectively located in the suction section 11, the middle section 15 and the discharge section 24. The end face of the final-stage impeller 21 is provided with a sealing ring 20, and the discharge section 24 is provided with a discharge section liner ring 25. A sealing cavity is formed between the end face of the sealing ring 20 and the end face of the discharge section liner ring 25, and the sealing cavity is connected with the suction section 11 through the rear cavity of the discharge section 24.

[0049] Preferably, the driving end of the pump shaft 2 is installed with a pump coupling 1 and a shaft nut 3, the shaft nut 3 is installed in the bearing body armor 7, the cylindrical roller bearing 5 at the driving end of the pump shaft 2 is installed in the bearing body armor 7, one end of the cylindrical roller bearing 5 is provided with a perforated bearing end cover 4, and the other end face of the cylindrical roller bearing 5 is provided with a bearing stop sleeve 6 in sequence.

[0050] Preferably, a shaft sleeve 8, a packing gland 9 and a packing ring 10 are sequentially arranged on the pump shaft 2 of the suction section 11;

[0051] A stuffing box body 26 is provided behind the discharge section 24, the bearing body A 7 is installed in front of the stuffing ring 10, and the bearing body B 27 is installed behind the stuffing box body 26;

[0052] A balancing water pipe assembly 17 is provided on the stuffing box body 26 , and the balancing water pipe assembly 17 is connected with the suction section 11 and the discharge section 24 .

[0053] Preferably, the cylindrical roller bearing 5 and the angular contact ball bearing 33 at the non-driving end of the pump shaft 2 are both installed in the bearing body B 27, the non-driving end of the pump shaft 2 is installed with a water retaining ring 28 and a bearing spacer 29, a gasket 30 is installed at one end of the angular contact ball bearing 33, a bearing sleeve 31 is provided outside the angular contact ball bearing 33, and a non-hole bearing end cover 34 and a round nut 35 are provided at the other end of the angular contact ball bearing 33.

[0054] Preferably, a first-stage sealing ring 12 is provided on the end face of the first-stage impeller 13 , a guide vane 14 is provided outside the impeller 18 , a guide vane sleeve 19 is provided outside the guide vane 14 , and a last-stage guide vane 22 is provided outside the last-stage impeller 21 .

[0055] The working principle and beneficial effects of the above technical solution are as follows: on the basis of the existing ordinary segmented multi-stage centrifugal pump, the original balancing mechanism is cancelled, and a sealing ring 20 is arranged on the back of the last-stage impeller 21. The end face of the sealing ring 20 and the end face of the discharge segment liner ring 25 installed on the discharge segment 24 form a sealing cavity, and the sealing cavity is connected with the suction cavity through the discharge segment rear cavity. At the same time, a pair of single-row angular contact ball bearings 33 are added on the outer side of the non-driving end cylindrical roller bearing. After the pump is started, the axial force directed to the driving end generated by the first N-1 stage impeller is balanced by the axial force directed to the non-driving end generated by the last-stage impeller 21 due to the sealing ring 20 arranged on the back, and the residual axial force is borne by the pair of single-row angular contact ball bearings 33, thereby reducing wear and extending the service life of the pump;

[0056] After the pump is filled with liquid, the motor is started, and the pump shaft 2 is driven to rotate through the pump coupling 1, and the impeller 18 on the pump shaft 2 rotates accordingly. The liquid is thrown out of the impeller 18 under the action of the centrifugal force of the impeller, and a certain vacuum is created at the suction port of the first-stage impeller 13. The liquid enters the pump through the suction section 11 under the action of the suction liquid surface pressure. After the liquid is thrown out from the first-stage impeller 13, it smoothly enters the forward guide vane in the same direction as the liquid flow rate, continues to flow outward along the forward guide vane, bypasses the internal partition plate of the guide vane 14 in the axial direction, and then flows inward along the reverse guide vane, enters the next-stage impeller 18 in the axial direction, and is finally discharged from the discharge section 24 to the liquid outlet pipe;

[0057] A sealing device with adjustable end face clearance, i.e., a sealing ring 20, is arranged behind the last stage impeller 21. The sealing cavity formed by the sealing device is connected to the suction section 11 through the balancing water pipe assembly 17. When the pump is running, the first N-1 stage impeller generates an axial force pointing to the driving end, and the last stage impeller 21 generates an axial force pointing to the non-driving end, so that the axial force is automatically balanced;

[0058] A set of cylindrical roller bearings 5 ​​are installed at the driving end and the non-driving end to bear the radial force generated by the rotor components. At the same time, a pair of single-row angular contact ball bearings 33 are installed at the non-driving end. The pair of bearings are installed in the bearing bushing 31. The bearing bushing 31 and the angular contact ball bearing 33 are clearance-fitted to ensure that the pair of bearings only bear axial force.

[0059] A set of gaskets 30 is arranged in front of a pair of single-row angular contact ball bearings 33 at the non-driving end. By adjusting the thickness of the gaskets 30, the end face sealing gap behind the last-stage impeller 21 can be adjusted to ensure the balance of axial force and control the leakage.

[0060] Example 2

[0061] On the basis of Example 1, an anti-blocking and anti-wear component 36 is installed at the suction section 11, and the anti-blocking and anti-wear component 36 includes an L-shaped anti-blocking and anti-wear component shell 37, the input end of the L-shaped anti-blocking and anti-wear component shell 37 is an inclined end face, and is provided with a filter screen 1 39, and the output end is bolted with a conical adapter 38, and the conical adapter 38 is used to cooperate with the inner wall of the suction section 11. A large impurity collection chamber 40 is provided in the L-shaped anti-blocking and anti-wear component shell 37, and a filter screen 2 50 is provided at the inlet of the large impurity collection chamber 40, and a claw 51 is rotatably connected to the rear of the filter screen 2 50;

[0062] A guide rod 41 is fixedly connected inside the large impurity collecting chamber 40, and a pressure plate 42 is connected to the guide rod 41 by sliding up and down. The top of the pressure plate 42 is connected to the inner wall of the large impurity collecting chamber 40 by an elastic part, and a steel rope 43 is fixedly connected to the bottom of the pressure plate 42. The other end of the steel rope 43 is wound around an electric winding wheel 44. A linkage closing plate 45 is rotatably connected to the large impurity collecting chamber 40, and a negative pressure impeller 46 is rotatably connected inside the large impurity collecting chamber 40. A drainage net 47 is provided behind the negative pressure impeller 46. An arc-shaped guide groove 48 for fine sand is provided relative to the drainage net 47 on the inner wall of the L-shaped anti-blocking and anti-wear component shell 37, and a sand discharge auger 49 is rotatably connected inside the arc-shaped guide groove 48 for fine sand.

[0063] The working principle and beneficial effects of the above technical solution are as follows: after the silt and large impurities enter the L-shaped anti-blocking and anti-wear component shell 37, they are first filtered through the filter screen 39. When the large impurities move to the scoop claw 51, the scoop claw 51 rotates and drives it to the inlet of the large impurity collection chamber 40. Under the action of the negative pressure generated by the rotation of the negative pressure impeller 46, the large impurities are sucked into the large impurity collection chamber 40, and then accumulate in the large impurity collection chamber 40. During the rotation of the negative pressure impeller 46, water will be discharged from the drainage net 47. The water discharged from the drainage net 47 forms resistance to the water flow entering the L-shaped anti-blocking and anti-wear component shell 37. The silt in the water flow entering the L-shaped anti-blocking and anti-wear component shell 37 is discharged to the fine sand arc guide groove 48 under the action of the resistance, and finally discharged through the sand discharge auger 49 after accumulation. The linkage closing plate 45 is in a horizontal state when not filtering large impurities, so as to prevent the impurities in the large impurity collection chamber 40 from being sucked out.

[0064] When the negative pressure of the negative pressure impeller 46 cannot suck the large impurities into the large impurity collecting chamber 40, the electric winding wheel 44 rotates to pull the steel rope 43 to move the pressure plate 42 downward, pressing the large impurities from the inlet of the large impurity collecting chamber 40 into the large impurity collecting chamber 40.

[0065] Example 3

[0066] Based on Example 1, a multi-stage centrifugal pump monitoring system includes:

[0067] A data collection time determination module is used to determine a number of data collection times of the current monitoring period based on the current monitoring period;

[0068] The data collection module is used to collect data based on several data collection moments in the current monitoring cycle, including:

[0069] A flow acquisition unit for collecting the flow of the suction section 11 and the discharge section 24, a pressure acquisition unit for collecting the pressure of the suction section 11 and the discharge section 24, a vibration signal acquisition unit for collecting the vibration signal of a multi-stage centrifugal pump, an ultrasonic signal acquisition unit for collecting the ultrasonic signal of a multi-stage centrifugal pump, and a power acquisition unit for collecting the power of a multi-stage centrifugal pump;

[0070] A performance evaluation value determination module is used to input the collection results of the flow collection unit, the pressure collection unit, the vibration signal collection unit, the ultrasonic signal collection unit and the power collection unit at several data collection moments into the trained multi-stage centrifugal pump delivery capacity evaluation model, the multi-stage centrifugal pump head capacity evaluation model, the multi-stage centrifugal pump mechanical state evaluation model, the multi-stage centrifugal pump sealing performance evaluation model and the multi-stage centrifugal pump energy efficiency evaluation model, respectively, to obtain the multi-stage centrifugal pump delivery capacity evaluation value, the multi-stage centrifugal pump head capacity evaluation value, the multi-stage centrifugal pump mechanical state evaluation value, the multi-stage centrifugal pump sealing performance evaluation value and the multi-stage centrifugal pump energy efficiency evaluation value at several data collection moments;

[0071] A monitoring matrix construction module, used to construct a monitoring matrix of a multi-stage centrifugal pump in the current monitoring period based on a number of data collection values ​​collected by the data collection module at a number of data collection moments in the current monitoring period and a number of evaluation values ​​obtained by the performance evaluation value determination module at a number of data collection moments in the current monitoring period;

[0072] The multi-stage centrifugal pump operation status analysis module is used to analyze the delivery capacity status, head capacity status, mechanical status, sealing performance status, and energy efficiency status of the multi-stage centrifugal pump based on the multi-stage centrifugal pump monitoring matrix in the current monitoring period, and to issue an emergency alarm prompt for the corresponding status performance based on the analysis results, or to predict the overall operation status evaluation value of the multi-stage centrifugal pump, and to issue an overall performance early warning prompt for the multi-stage centrifugal pump based on the prediction results.

[0073] Preferably, the flow acquisition unit, the pressure acquisition unit, the vibration signal acquisition unit, the ultrasonic signal acquisition unit and the power acquisition unit are respectively acquired using a flow sensor, a pressure sensor, a vibration sensor, an ultrasonic sensor and a power sensor.

[0074] Preferably, the trained multi-stage centrifugal pump delivery capacity assessment model is a model obtained by pre-using a large amount of flow collection data from the suction section 11 and the discharge section 24 as the model input of the training sample, and using the multi-stage centrifugal pump delivery capacity assessment value corresponding to the flow collection data from the suction section 11 and the discharge section 24 as the model output, and performing neural network training.

[0075] The trained multi-stage centrifugal pump head capacity evaluation model is a model obtained after neural network training by pre-using the pressure collection data of the suction section 11 and the discharge section 24 as the model input of the training sample, and using the multi-stage centrifugal pump head capacity evaluation value corresponding to the pressure collection data of the suction section 11 and the discharge section 24 as the model output.

[0076] The trained multi-stage centrifugal pump mechanical condition assessment model is a model obtained after neural network training by pre-using the multi-stage centrifugal pump vibration signal acquisition data (including vibration velocity and vibration acceleration) as the model input of the training sample, and using the multi-stage centrifugal pump mechanical condition assessment value corresponding to the multi-stage centrifugal pump vibration signal acquisition data as the model output.

[0077] The trained multi-stage centrifugal pump sealing performance evaluation model is a model obtained after neural network training by pre-using the multi-stage centrifugal pump ultrasonic signal acquisition data (including sound pressure level and frequency) as the model input of the training sample, and using the multi-stage centrifugal pump sealing performance evaluation value corresponding to the multi-stage centrifugal pump ultrasonic signal acquisition data as the model output.

[0078] The trained multi-stage centrifugal pump energy efficiency evaluation model is a model obtained after neural network training by pre-using the multi-stage centrifugal pump power collection data as the model input of the training sample, and using the multi-stage centrifugal pump energy efficiency evaluation value corresponding to the multi-stage centrifugal pump power collection data as the model output.

[0079] The working principle and beneficial effects of the above technical solution are as follows: through the data acquisition module, multiple key data can be collected at different times in the current monitoring cycle, including flow, pressure, vibration signal, ultrasonic signal and power. These data can provide detailed information on the pump operation status. The collected data will be input into the trained evaluation model to evaluate the pump's delivery capacity, head capacity, mechanical state, sealing performance and energy efficiency respectively. These evaluation values ​​can be used as indicators of the pump's working status. The monitoring matrix construction module combines the collected data and performance evaluation values ​​to construct a multi-stage centrifugal pump monitoring matrix for the current monitoring cycle. Through the structure of the matrix, analysis and comparison can be more convenient. The multi-stage centrifugal pump operation status analysis module analyzes and judges the pump's delivery capacity status, head capacity status, mechanical status, sealing performance status and energy efficiency status based on the monitoring matrix. When it is found that the status is unqualified, the system will promptly issue an emergency alarm to remind the operator to check and maintain. When all the status are qualified, the multi-stage centrifugal pump operation status analysis module can also predict the overall operation status of the pump based on the analysis results, warn the overall performance of the pump in advance, and provide guidance for maintenance and maintenance.

[0080] Example 4

[0081] Based on Example 3, the monitoring matrix construction module constructs the monitoring matrix of the multi-stage centrifugal pump in the current monitoring period, including:

[0082] in, is the monitoring matrix of the multi-stage centrifugal pump in the i-th monitoring period, a i1 is the flow difference between the suction section 11 and the discharge section 24 collected by the flow collection unit at the first data collection moment of the i-th monitoring cycle, a i2 is the flow difference between the suction section 11 and the discharge section 24 collected by the flow collection unit at the second data collection time of the i-th monitoring cycle, a in is the flow difference between the suction section 11 and the discharge section 24 collected by the flow collection unit at the nth data collection moment in the ith monitoring cycle, b i1 is the pressure difference between the suction section 11 and the discharge section 24 collected by the pressure collection unit at the first data collection moment of the i-th monitoring cycle, b i2 is the pressure difference between the suction section 11 and the discharge section 24 collected by the pressure collection unit at the second data collection moment in the i-th monitoring cycle, b in is the pressure difference between the suction section 11 and the discharge section 24 collected by the pressure collection unit at the nth data collection moment in the ith monitoring cycle, c i1 is the vibration velocity collected by the vibration signal acquisition unit at the first data acquisition moment of the i-th monitoring cycle, c i2is the vibration velocity collected by the vibration signal acquisition unit at the second data acquisition moment of the i-th monitoring cycle, c in is the vibration speed collected by the vibration signal collection unit at the nth data collection moment in the ith monitoring cycle, d i1 is the sound pressure level value collected by the ultrasonic signal acquisition unit at the first data acquisition moment of the i-th monitoring cycle, d i2 is the sound pressure level value collected by the ultrasonic signal acquisition unit at the second data acquisition moment in the i-th monitoring cycle, d in is the sound pressure level value collected by the ultrasonic signal acquisition unit at the nth data acquisition moment in the ith monitoring cycle, e i1 is the power value collected by the power collection unit at the first data collection moment in the i-th monitoring cycle, e i2 is the power value collected by the power collection unit at the second data collection moment in the i-th monitoring cycle, e in is the power value collected by the power collection unit at the nth data collection moment in the ith monitoring cycle, A i1 is the estimated value of the multi-stage centrifugal pump delivery capacity at the first data collection moment in the i-th monitoring period, A i2 is the estimated value of the multi-stage centrifugal pump delivery capacity at the second data collection moment in the i-th monitoring period, A in is the estimated value of the multi-stage centrifugal pump delivery capacity at the nth data collection moment in the ith monitoring period, B i1 is the head capacity evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring period, B i2 is the head capacity evaluation value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring period, B in is the head capacity evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring period, C i1 is the mechanical condition assessment value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring cycle, C i2 is the mechanical condition assessment value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring cycle, C in is the mechanical condition evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring cycle, D i1 is the sealing performance evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring cycle, D i2 is the sealing performance evaluation value of the multistage centrifugal pump at the second data collection moment in the ith monitoring cycle, D in is the sealing performance evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring cycle, E i1 is the energy efficiency evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring period, E i2 is the energy efficiency evaluation value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring cycle, E inIt is the energy efficiency evaluation value of the multi-stage centrifugal pump at the nth data collection moment in the ith monitoring cycle.

[0083] The working principle and beneficial effects of the above technical solution: the multi-stage centrifugal pump monitoring matrix includes parameters such as the flow difference between the suction section 11 and the discharge section 24 at several data collection moments, the pressure difference between the suction section 11 and the discharge section 24, the vibration velocity, the sound pressure level value, the power value, etc. The selection of these parameters covers the key performance indicators of the pump and can comprehensively and accurately reflect the working status of the pump. At the same time, the multi-stage centrifugal pump monitoring matrix includes the multi-stage centrifugal pump delivery capacity evaluation value, the multi-stage centrifugal pump head capacity evaluation value, the multi-stage centrifugal pump mechanical state evaluation value, the multi-stage centrifugal pump sealing performance evaluation value and the multi-stage centrifugal pump energy efficiency evaluation value at several data collection moments, which can intuitively display the performance indicators and evaluation results of the pump, and facilitate further analysis and judgment. Selecting several data collection moments in the same monitoring cycle can increase the reliability of the multi-stage centrifugal pump monitoring matrix. The establishment of the matrix is ​​conducive to further optimizing the operation and maintenance of the pump.

[0084] Example 5

[0085] Based on Example 3, the multi-stage centrifugal pump operation status analysis module includes:

[0086] The traversal analysis unit is used to obtain the delivery capacity state matrix, head capacity state matrix, mechanical state matrix, sealing performance state matrix and energy efficiency state matrix of the multistage centrifugal pump in the current monitoring period based on the multistage centrifugal pump monitoring matrix in the current monitoring period:

[0087] Delete the collected values ​​of the flow collection unit and the multi-stage centrifugal pump delivery capacity evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period, and obtain the delivery capacity state matrix of the multi-stage centrifugal pump in the current monitoring period;

[0088] Delete the collected values ​​of the pressure collection unit and the head capacity evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the head capacity state matrix of the multistage centrifugal pump in the current monitoring period;

[0089] Delete the collected values ​​of the vibration signal collection unit and the mechanical state evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the mechanical state matrix of the multistage centrifugal pump in the current monitoring period;

[0090] Delete the collected values ​​of the ultrasonic signal collection unit and the sealing performance evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the sealing performance status matrix of the multistage centrifugal pump in the current monitoring period;

[0091] Delete the collected values ​​of the power collection unit and the energy efficiency evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the energy efficiency state matrix of the multistage centrifugal pump in the current monitoring period;

[0092] The alarm judgment unit compares the ranks of the conveying capacity state matrix, the lift capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix with the benchmark evaluation values ​​of the corresponding states. If the ranks of the conveying capacity state matrix, the lift capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix are greater than the benchmark evaluation values ​​of the corresponding states, the corresponding states are unqualified, and an emergency alarm prompt for the corresponding state performance is issued. Otherwise, the overall operation state evaluation value of the multi-stage centrifugal pump is predicted;

[0093] The overall operation status evaluation value prediction unit is used to predict the overall operation status evaluation value of the multi-stage centrifugal pump in the next monitoring cycle, and determine whether to issue an overall performance early warning prompt for the multi-stage centrifugal pump based on the prediction result.

[0094] The working principle and beneficial effects of the above technical solution are as follows: based on the monitoring matrix of the multi-stage centrifugal pump in the current monitoring period, the conveying capacity state matrix, the head capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix of the multi-stage centrifugal pump in the current monitoring period are obtained, and the alarm judgment unit compares the ranks of the conveying capacity state matrix, the head capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix with the benchmark evaluation values ​​of the corresponding states. If the ranks of these matrices are greater than the benchmark evaluation values ​​of the corresponding states, it means that the state is unqualified, and the system will issue an emergency alarm prompt, which will help the staff to accurately locate and quickly identify the problem and take corresponding measures. If all are qualified, the overall operating state evaluation value of the multi-stage centrifugal pump in the next monitoring period is predicted, and based on the prediction results, it is determined whether to issue an early warning prompt for the overall performance of the multi-stage centrifugal pump. The alarm prompt ensures the timely repair of the unqualified state, and the early warning prompt can avoid the alarm prompt in the next monitoring period. Prevention is better than maintenance, which can greatly reduce the economic losses caused by centrifugal pump failures, reduce downtime and maintenance costs, and is conducive to increasing the service life of the centrifugal pump.

[0095] Example 6

[0096] On the basis of Embodiment 5, the overall operation status evaluation value prediction unit includes:

[0097] The overall operation status evaluation value determination subunit of the multistage centrifugal pump is used to calculate the rank of the monitoring matrix of the multistage centrifugal pump in the current monitoring period as the overall operation status evaluation value of the multistage centrifugal pump in the current monitoring period;

[0098] The overall operation status evaluation value prediction matrix construction subunit of the multistage centrifugal pump is used to construct the overall operation status evaluation value prediction matrix of the multistage centrifugal pump based on the overall operation status evaluation values ​​of the multistage centrifugal pump in several monitoring periods:

[0099] Among them, W i is the prediction matrix of the overall operating status evaluation value of the multistage centrifugal pump in the i-th monitoring period, w 1 is the overall operating status evaluation value of the multistage centrifugal pump in the first monitoring cycle, w 2 is the overall operating status evaluation value of the multistage centrifugal pump in the second monitoring cycle, w 3 is the overall operating status evaluation value of the multistage centrifugal pump in the third monitoring cycle, w i-1 is the overall operating status evaluation value of the multistage centrifugal pump in the i-1th monitoring cycle, w i is the overall operating status evaluation value of the multi-stage centrifugal pump in the i-th monitoring period;

[0100] The prediction value determination subunit obtains the mean value of all matrix elements in the third column of the prediction matrix of the overall operation status evaluation value of the multistage centrifugal pump in the i-th monitoring period, and replaces the values ​​of all matrix elements in the third row of the prediction matrix of the overall operation status evaluation value of the multistage centrifugal pump in the i-th monitoring period with the mean value of all matrix elements in the third column to obtain a new matrix, and uses the rank of the new matrix as the overall operation status evaluation value of the multistage centrifugal pump in the i+1-th monitoring period;

[0101] The early warning judgment unit issues an early warning prompt if the overall operating status evaluation value of the multi-stage centrifugal pump in the (i+1)th monitoring period is less than a preset overall operating status evaluation value of the multi-stage centrifugal pump.

[0102] The working principle and beneficial effects of the above technical solution are as follows: by calculating the rank of the monitoring matrix of the multi-stage centrifugal pump in the current monitoring period, the rank is used as the overall operating status evaluation value of the multi-stage centrifugal pump in the current monitoring period. The rank reflects the correlation and change trend of each data in the monitoring matrix, and can be used as a measure of the overall operating status of the pump. By calculating the mean of the elements in the third column and replacing the elements in the third row with the mean, the mutation and fluctuation of the data can be reduced, which helps to remove the influence of noise and outliers and improve the reliability and stability of the evaluation value. Due to the accumulation of transmission errors of the evaluation values, the value of the third row in the prediction matrix may deviate greatly from the actual situation. By replacing the value of the third row with the mean of the third column, the error transmission can be reduced, and the overall operating status of the next cycle can be predicted more accurately. After calculating the mean in the third column, it is applied to the third row, which can balance the influence of different evaluation values ​​in the overall operating status evaluation value prediction matrix, maintain comprehensive consideration of the overall operating status evaluation, and avoid excessive influence of a specific evaluation value on the prediction result.

[0103] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A multistage centrifugal pump, characterized in that: The invention comprises a pump shaft (2), wherein the driving end and the non-driving end of the pump shaft (2) are both equipped with cylindrical roller bearings (5), and the non-driving end of the pump shaft (2) is equipped with a pair of single-row angular contact ball bearings (33). The pump shaft (2) is provided with a first-stage impeller (13), an impeller (18) and a last-stage impeller (21), wherein the first-stage impeller (13), the impeller (18) and the last-stage impeller (21) are respectively located at the suction section (11), the middle section (15) and the discharge section (24), wherein a sealing ring (20) is provided at the end face of the last-stage impeller (21), and a discharge section lining ring (25) is provided in the discharge section (24), wherein a sealing cavity is formed between the end face of the sealing ring (20) and the end face of the discharge section lining ring (25), and wherein the sealing cavity is connected with the suction section (11) through the rear cavity of the discharge section (24).

2. A multistage centrifugal pump according to claim 1, characterized in that: A pump coupling (1) and a shaft nut (3) are installed at the driving end of the pump shaft (2). The shaft nut (3) is installed in a bearing body (7). A cylindrical roller bearing (5) at the driving end of the pump shaft (2) is installed in the bearing body (7). A bearing end cover (4) with a hole is provided at one end of the cylindrical roller bearing (5). A bearing stopper sleeve (6) is provided in sequence at the other end surface of the cylindrical roller bearing (5).

3. A multistage centrifugal pump according to claim 1, characterized in that: A shaft sleeve (8), a packing gland (9) and a packing ring (10) are sequentially arranged on the pump shaft (2) of the suction section (11); A stuffing box body (26) is arranged behind the discharge section (24), a bearing body A (7) is installed in front of the stuffing ring (10), and a bearing body B (27) is installed behind the stuffing box body (26); A balancing water pipe assembly (17) is provided on the stuffing box body (26), and the balancing water pipe assembly (17) is communicated with the suction section (11) and the discharge section (24).

4. A multistage centrifugal pump according to claim 3, characterized in that: The cylindrical roller bearing (5) and the angular contact ball bearing (33) at the non-driving end of the pump shaft (2) are both installed in the bearing body B (27). The non-driving end of the pump shaft (2) is installed with a water retaining ring (28) and a bearing spacer (29). One end of the angular contact ball bearing (33) is installed with a gasket (30). The angular contact ball bearing (33) is provided with a bearing bushing (31) outside. The other end of the angular contact ball bearing (33) is provided with a non-hole bearing end cover (34) and a round nut (35).

5. A multistage centrifugal pump according to claim 1, characterized in that: A first-stage sealing ring (12) is provided on the end surface of the first-stage impeller (13), a guide vane (14) is provided outside the impeller (18), a guide vane sleeve (19) is provided outside the guide vane (14), and a last-stage guide vane (22) is provided outside the last-stage impeller (21).

6. A multistage centrifugal pump according to claim 1, characterized in that: An anti-blocking and anti-wear component (36) is installed at the suction section (11), and the anti-blocking and anti-wear component (36) includes an L-shaped anti-blocking and anti-wear component shell (37). The input end of the L-shaped anti-blocking and anti-wear component shell (37) is an inclined end face and is provided with a filter screen (39). The output end is bolted with a conical adapter (38), and the conical adapter (38) is used to cooperate with the inner wall of the suction section (11). A large impurity collection chamber (40) is provided in the L-shaped anti-blocking and anti-wear component shell (37). A filter screen (50) is provided at the inlet of the large impurity collection chamber (40), and a claw (51) is rotatably connected to the rear of the filter screen (50); A guide rod (41) is fixedly connected in the large impurity collection chamber (40), and a pressure plate (42) is slidably connected to the guide rod (41) up and down. The top of the pressure plate (42) is connected to the inner wall of the large impurity collection chamber (40) through an elastic member, and a steel rope (43) is fixedly connected to the bottom of the pressure plate (42). The other end of the steel rope (43) is wound around an electric winding wheel (44). The large impurity collection chamber (40) is rotatably connected to a linkage closing plate (45). A negative pressure impeller (46) is rotatably connected in the large impurity collection chamber (40), and a drainage net (47) is arranged behind the negative pressure impeller (46). A fine sand arc guide groove (48) is arranged at a position opposite to the drainage net (47) on the inner wall of the L-shaped anti-blocking and anti-wear component housing (37), and a sand discharge auger (49) is rotatably connected in the fine sand arc guide groove (48).

7. A multi-stage centrifugal pump monitoring system, used for monitoring a multi-stage centrifugal pump as claimed in claims 1-6, characterized in that: include: A data collection time determination module is used to determine a number of data collection times of the current monitoring period based on the current monitoring period; The data collection module is used to collect data based on several data collection moments in the current monitoring cycle, including: A flow acquisition unit for acquiring the flow of the suction section (11) and the discharge section (24), a pressure acquisition unit for acquiring the pressure of the suction section (11) and the discharge section (24), a vibration signal acquisition unit for acquiring the vibration signal of the multi-stage centrifugal pump, an ultrasonic signal acquisition unit for acquiring the ultrasonic signal of the multi-stage centrifugal pump, and a power acquisition unit for acquiring the power of the multi-stage centrifugal pump; A performance evaluation value determination module is used to input the collection results of the flow collection unit, the pressure collection unit, the vibration signal collection unit, the ultrasonic signal collection unit and the power collection unit at several data collection moments into the trained multi-stage centrifugal pump delivery capacity evaluation model, the multi-stage centrifugal pump head capacity evaluation model, the multi-stage centrifugal pump mechanical state evaluation model, the multi-stage centrifugal pump sealing performance evaluation model and the multi-stage centrifugal pump energy efficiency evaluation model, respectively, to obtain the multi-stage centrifugal pump delivery capacity evaluation value, the multi-stage centrifugal pump head capacity evaluation value, the multi-stage centrifugal pump mechanical state evaluation value, the multi-stage centrifugal pump sealing performance evaluation value and the multi-stage centrifugal pump energy efficiency evaluation value at several data collection moments; A monitoring matrix construction module, used to construct a monitoring matrix of a multi-stage centrifugal pump in the current monitoring period based on a number of data collection values ​​collected by the data collection module at a number of data collection moments in the current monitoring period and a number of evaluation values ​​obtained by the performance evaluation value determination module at a number of data collection moments in the current monitoring period; The multi-stage centrifugal pump operation status analysis module is used to analyze the delivery capacity status, head capacity status, mechanical status, sealing performance status, and energy efficiency status of the multi-stage centrifugal pump based on the multi-stage centrifugal pump monitoring matrix in the current monitoring period, and to issue an emergency alarm prompt for the corresponding status performance based on the analysis results, or to predict the overall operation status evaluation value of the multi-stage centrifugal pump, and to issue an overall performance early warning prompt for the multi-stage centrifugal pump based on the prediction results.

8. A multi-stage centrifugal pump monitoring system according to claim 7, characterized in that: The monitoring matrix building module builds the monitoring matrix of the multi-stage centrifugal pump in the current monitoring period, including: in, is the monitoring matrix of the multi-stage centrifugal pump in the i-th monitoring period, a i1 is the flow difference between the suction section (11) and the discharge section (24) collected by the flow collection unit at the first data collection moment in the i-th monitoring cycle, a i2 is the flow difference between the suction section (11) and the discharge section (24) collected by the flow collection unit at the second data collection moment in the i-th monitoring cycle, a in is the flow difference between the suction section (11) and the discharge section (24) collected by the flow collection unit at the nth data collection moment in the ith monitoring cycle, b i1 is the pressure difference between the suction section (11) and the discharge section (24) collected by the pressure collection unit at the first data collection moment in the i-th monitoring cycle, b i2 is the pressure difference between the suction section (11) and the discharge section (24) collected by the pressure collection unit at the second data collection moment in the i-th monitoring cycle, b in is the pressure difference between the suction section (11) and the discharge section (24) collected by the pressure collection unit at the nth data collection moment in the ith monitoring cycle, c i1 is the vibration velocity collected by the vibration signal acquisition unit at the first data acquisition moment of the i-th monitoring cycle, c i2 is the vibration velocity collected by the vibration signal acquisition unit at the second data acquisition moment of the i-th monitoring cycle, c in is the vibration speed collected by the vibration signal collection unit at the nth data collection moment in the ith monitoring cycle, d i1 is the sound pressure level value collected by the ultrasonic signal acquisition unit at the first data acquisition moment of the i-th monitoring cycle, d i2 is the sound pressure level value collected by the ultrasonic signal acquisition unit at the second data acquisition moment in the i-th monitoring cycle, d in is the sound pressure level value collected by the ultrasonic signal acquisition unit at the nth data acquisition moment in the ith monitoring cycle, e i1 is the power value collected by the power collection unit at the first data collection moment in the i-th monitoring cycle, e i2 is the power value collected by the power collection unit at the second data collection moment in the i-th monitoring cycle, e in is the power value collected by the power collection unit at the nth data collection moment in the ith monitoring cycle, A i1 is the estimated value of the multi-stage centrifugal pump delivery capacity at the first data collection moment in the i-th monitoring period, A i2 is the estimated value of the multi-stage centrifugal pump delivery capacity at the second data collection moment in the ith monitoring period, A in is the estimated value of the multi-stage centrifugal pump delivery capacity at the nth data collection moment in the ith monitoring period, B i1 is the head capacity evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring period, B i2 is the head capacity evaluation value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring period, B in is the head capacity evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring period, C i1 is the mechanical condition assessment value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring cycle, C i2 is the mechanical condition assessment value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring cycle, C in is the mechanical condition evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring cycle, D i1 is the sealing performance evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring cycle, D i2 is the sealing performance evaluation value of the multistage centrifugal pump at the second data collection moment in the ith monitoring cycle, D in is the sealing performance evaluation value of the multistage centrifugal pump at the nth data collection moment in the ith monitoring cycle, E i1 is the energy efficiency evaluation value of the multistage centrifugal pump at the first data collection moment in the i-th monitoring period, E i2 is the energy efficiency evaluation value of the multistage centrifugal pump at the second data collection moment in the i-th monitoring cycle, E in It is the energy efficiency evaluation value of the multi-stage centrifugal pump at the nth data collection moment in the ith monitoring cycle.

9. A multi-stage centrifugal pump monitoring system according to claim 7, characterized in that: The multistage centrifugal pump operation status analysis module includes: The traversal analysis unit is used to obtain the delivery capacity state matrix, head capacity state matrix, mechanical state matrix, sealing performance state matrix and energy efficiency state matrix of the multistage centrifugal pump in the current monitoring period based on the multistage centrifugal pump monitoring matrix in the current monitoring period: Delete the collected values ​​of the flow collection unit and the multi-stage centrifugal pump delivery capacity evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period, and obtain the delivery capacity state matrix of the multi-stage centrifugal pump in the current monitoring period; Delete the collected values ​​of the pressure collection unit and the head capacity evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the head capacity state matrix of the multistage centrifugal pump in the current monitoring period; Delete the collected values ​​of the vibration signal collection unit and the mechanical state evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the mechanical state matrix of the multistage centrifugal pump in the current monitoring period; Delete the collected values ​​of the ultrasonic signal collection unit and the sealing performance evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the sealing performance status matrix of the multistage centrifugal pump in the current monitoring period; Delete the collected values ​​of the power collection unit and the energy efficiency evaluation value of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the energy efficiency state matrix of the multistage centrifugal pump in the current monitoring period; The alarm judgment unit compares the ranks of the conveying capacity state matrix, the lift capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix with the benchmark evaluation values ​​of the corresponding states. If the ranks of the conveying capacity state matrix, the lift capacity state matrix, the mechanical state matrix, the sealing performance state matrix and the energy efficiency state matrix are greater than the benchmark evaluation values ​​of the corresponding states, the corresponding states are unqualified, and an emergency alarm prompt for the corresponding state performance is issued. Otherwise, the overall operation state evaluation value of the multi-stage centrifugal pump is predicted; The overall operation status evaluation value prediction unit is used to predict the overall operation status evaluation value of the multi-stage centrifugal pump in the next monitoring cycle, and determine whether to issue an overall performance early warning prompt for the multi-stage centrifugal pump based on the prediction result.

10. A multi-stage centrifugal pump monitoring system according to claim 9, characterized in that: The overall operation status evaluation value prediction unit includes: The overall operation status evaluation value determination subunit of the multistage centrifugal pump is used to calculate the rank of the monitoring matrix of the multistage centrifugal pump in the current monitoring period as the overall operation status evaluation value of the multistage centrifugal pump in the current monitoring period; The overall operation status evaluation value prediction matrix construction subunit of the multistage centrifugal pump is used to construct the overall operation status evaluation value prediction matrix of the multistage centrifugal pump based on the overall operation status evaluation values ​​of the multistage centrifugal pump in several monitoring periods: Among them, W i is the prediction matrix of the overall operation status evaluation value of the multistage centrifugal pump in the i-th monitoring period, w1 is the overall operation status evaluation value of the multistage centrifugal pump in the first monitoring period, w2 is the overall operation status evaluation value of the multistage centrifugal pump in the second monitoring period, w3 is the overall operation status evaluation value of the multistage centrifugal pump in the third monitoring period, w i-1 is the overall operating status evaluation value of the multistage centrifugal pump in the i-1th monitoring period, w i is the overall operating status evaluation value of the multi-stage centrifugal pump in the i-th monitoring period; The prediction value determination subunit obtains the mean value of all matrix elements in the third column of the prediction matrix of the overall operation status evaluation value of the multistage centrifugal pump in the i-th monitoring period, and replaces the values ​​of all matrix elements in the third row of the prediction matrix of the overall operation status evaluation value of the multistage centrifugal pump in the i-th monitoring period with the mean value of all matrix elements in the third column to obtain a new matrix, and uses the rank of the new matrix as the overall operation status evaluation value of the multistage centrifugal pump in the i+1-th monitoring period; The early warning judgment unit issues an early warning prompt if the overall operating status evaluation value of the multi-stage centrifugal pump in the (i+1)th monitoring period is less than a preset overall operating status evaluation value of the multi-stage centrifugal pump.

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