A multi-stage centrifugal pump and monitoring system

Abstract

The application provides a multi-stage centrifugal pump and a monitoring system, and relates to the technical field of multi-stage centrifugal pumps.The multi-stage centrifugal pump comprises a pump shaft, a pair of single-row angular contact ball bearings are installed on the non-driving end of the pump shaft, a first-stage impeller, an impeller and a last-stage impeller are arranged on the pump shaft, a sealing ring is arranged on the end face of the last-stage impeller, and a discharge section lining ring is arranged in the discharge section.The application cancels the original balance mechanism on the basis of the existing ordinary multi-stage centrifugal pump, a sealing cavity is formed between the end face of the sealing ring and the end face of the discharge section lining ring arranged on the discharge section, the sealing cavity is communicated with the suction cavity through the rear cavity of the discharge section, a pair of single-row angular contact ball bearings are additionally arranged outside the cylindrical roller bearing on the non-driving end, the axial force generated by the first N-1 stage impellers and directed to the driving end is balanced by the axial force generated by the last-stage impeller and directed to the non-driving end due to the sealing ring arranged on the back surface, and the residual axial force is borne by the pair of single-row angular contact ball bearings, so that the abrasion is reduced and the service life of the pump is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of multistage centrifugal pump technology, specifically relating to a multistage centrifugal pump and its monitoring system. Background Technology

[0002] Existing multistage centrifugal pumps are generally segmental multistage centrifugal pumps with single or double suction inlets. The pump's suction inlet is arranged horizontally, and the discharge outlet is arranged vertically upward. Its main components include: suction section, intermediate section, discharge section, stuffing box, impeller (including first-stage impeller), guide vanes (including last-stage guide vanes), balance disc, balance ring, balance sleeve, shaft, bearing housing, bearing, coupling, etc. The axial force generated by the pump during operation is balanced by the balancing mechanism (balance disc, balance ring, balance sleeve).

[0003] Its main drawback is the lack of axial force balancing components. The balance disc, balance ring, and balance sleeve are easily worn parts and need to be replaced when they wear to a certain extent. However, replacement is often difficult. At the same time, after the balance disc and balance ring wear down, the rotor moves towards the drive end, and the impeller and guide vane flow channel are misaligned. If they are not replaced in time, it will lead to increased internal losses, reduced flow, and decreased 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 technical problems mentioned above.

[0005] To solve the above-mentioned technical problems, the present invention discloses a multi-stage centrifugal pump, including a pump shaft. Both the driving end and the non-driving end of the pump shaft are 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 located in the suction section, the middle section, and the discharge section, respectively. The end face of the last-stage impeller is provided with a sealing ring. The discharge section is provided with a discharge section liner. A sealing cavity is formed between the end face of the sealing ring and the end face of the discharge section liner. The sealing cavity communicates with the suction section through the discharge section rear cavity.

[0006] Preferably, the pump shaft drive end is equipped with a pump coupling and a shaft nut, the shaft nut is installed in the bearing housing, the cylindrical roller bearing at the pump shaft drive end is installed in the bearing housing, one end of the cylindrical roller bearing is provided with a perforated bearing end cap, and the other end face of the cylindrical roller bearing is provided with bearing retainers arranged in sequence.

[0007] Preferably, the pump shaft in the suction section is provided with a shaft sleeve, a packing gland and a packing ring in sequence;

[0008] A stuffing box is installed 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.

[0009] The stuffing box is equipped with a balance water pipe assembly, which is connected to 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 housing B. A water baffle 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 bushing is provided outside the angular contact ball bearing. A holeless bearing end cap and a round nut are provided at the other end of the angular contact ball bearing.

[0011] Preferably, the first-stage impeller end face is provided with a first-stage sealing ring, the impeller is provided with guide vanes, the guide vanes are provided with guide vane sleeves, and the last-stage impeller is provided with last-stage guide vanes.

[0012] Preferably, an anti-clogging and anti-wear component is installed at the suction section. The anti-clogging and anti-wear component includes an L-shaped anti-clogging and anti-wear component housing. The input end of the L-shaped anti-clogging and anti-wear component housing is an inclined end face and is provided with a filter screen one. The output end is bolted to a conical adapter. The conical adapter is used to cooperate with the inner wall of the suction section. The L-shaped anti-clogging and anti-wear component housing is provided with a large impurity collection chamber. A filter screen two is provided at the inlet of the large impurity collection chamber. A scooping claw is rotatably connected behind the filter screen two.

[0013] A guide rod is fixedly connected inside the large impurity collection chamber. A pressure plate is slidably connected to the guide rod. The top of the pressure plate is connected to the inner wall of the large impurity collection chamber through an elastic element. A steel rope is fixedly connected to the bottom of the pressure plate. The other end of the steel rope is wound around an electric winding wheel. A linkage closing plate is rotatably connected to the large impurity collection chamber. A negative pressure impeller is rotatably connected inside the large impurity collection chamber. A drainage net is provided behind the negative pressure impeller. A fine sand arc-shaped guide groove is provided on the inner wall of the L-shaped anti-clogging and anti-wear component housing, with a sand discharge auger rotatably connected inside the fine sand arc-shaped guide groove.

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

[0015] The data acquisition time determination module is used to determine several data acquisition times for the current monitoring period based on the current monitoring period.

[0016] The data acquisition module is used to acquire data at several data acquisition points based on the current monitoring period, including:

[0017] Flow acquisition unit for flow acquisition in suction and discharge sections, pressure acquisition unit for pressure acquisition in suction and discharge sections, vibration signal acquisition unit for vibration signal acquisition in multi-stage centrifugal pumps, ultrasonic signal acquisition unit for ultrasonic signal acquisition in multi-stage centrifugal pumps, and power acquisition unit for power acquisition in multi-stage centrifugal pumps.

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

[0019] The monitoring matrix construction module is used to determine the evaluation values ​​obtained at several data acquisition moments in the current monitoring period of the data acquisition module based on several data acquisition values ​​and performance evaluation values ​​collected at several data acquisition moments in the current monitoring period of the data acquisition module, and to construct the multi-stage centrifugal pump monitoring matrix for the current monitoring period.

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

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

[0022] in, Let a be the multi-stage centrifugal pump monitoring matrix for the i-th monitoring cycle. i1 Let a be the flow difference between the inhalation and exhalation sections collected by the flow acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 Let a be the flow difference between the inhalation and exhalation sections collected by the flow acquisition unit at the second data acquisition time of the i-th monitoring cycle. in b is the flow difference between the inhalation and exhalation sections collected by the flow acquisition unit at the nth data acquisition time in the i-th monitoring cycle. i1 b is the pressure difference between the inhalation and exhalation sections collected by the pressure acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 b represents the pressure difference between the inhalation and exhalation sections collected by the pressure acquisition unit at the second data acquisition time of the i-th monitoring cycle. in Let c be the pressure difference between the inhalation and exhalation sections collected by the pressure acquisition unit at the nth data acquisition time of the i-th monitoring cycle. i1Let c be the vibration velocity collected by the vibration signal acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 Let c be the vibration velocity collected by the vibration signal acquisition unit at the second data acquisition time of the i-th monitoring cycle. in Let d be the vibration velocity collected by the vibration signal acquisition unit at the nth data acquisition time of the i-th monitoring cycle. i1 Let d be the sound pressure level value acquired by the ultrasonic signal acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 Let d be the sound pressure level value acquired by the ultrasonic signal acquisition unit at the second data acquisition time of the i-th monitoring cycle. in e represents the sound pressure level value acquired by the ultrasonic signal acquisition unit at the nth data acquisition time in the i-th monitoring cycle. i1 e represents the power value acquired by the power acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 e represents the power value acquired by the power acquisition unit at the second data acquisition time of the i-th monitoring cycle. in Let A be the power value collected by the power acquisition unit at the nth data acquisition time of the i-th monitoring cycle. i1 Let A be the evaluation value of the multi-stage centrifugal pump's delivery capacity at the first data acquisition time of the i-th monitoring cycle. i2 Let A be the evaluation value of the multi-stage centrifugal pump's delivery capacity at the second data acquisition time of the i-th monitoring cycle. in B is the evaluation value of the multi-stage centrifugal pump's delivery capacity at the nth data acquisition time in the i-th monitoring period. i1 B represents the head capacity assessment value of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2 B represents the head capacity assessment value of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. in C represents the head capacity assessment value of the multi-stage centrifugal pump at the nth data acquisition time in the i-th monitoring cycle. i1 C represents the mechanical condition assessment value of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2 C represents the mechanical condition assessment value of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. in D represents the mechanical condition assessment value of the multi-stage centrifugal pump at the nth data acquisition time in the i-th monitoring cycle. i1 D represents the evaluation value of the sealing performance of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2 D represents the evaluation value of the sealing performance of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. in E represents the evaluation value of the sealing performance of the multi-stage centrifugal pump at the nth data acquisition time in the i-th monitoring cycle. i1 E represents the energy efficiency assessment value of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2E represents the energy efficiency assessment value of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. in The value is the energy efficiency assessment value of the multi-stage centrifugal pump at the nth data acquisition time in the i-th 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 multi-stage centrifugal pumps in the current monitoring period, based on the multi-stage centrifugal pump monitoring matrix of the current monitoring period.

[0025] Delete the collected values ​​of the flow acquisition unit and the multi-stage centrifugal pump delivery capacity evaluation values ​​in the multi-stage centrifugal pump monitoring matrix for the current monitoring period, and obtain the delivery capacity status matrix of the multi-stage centrifugal pump for the current monitoring period.

[0026] Delete the collected values ​​of the pressure acquisition unit and the head capacity evaluation value of the multi-stage centrifugal pump in the monitoring matrix of the current monitoring period, and obtain the head capacity status matrix of the multi-stage centrifugal pump in the current monitoring period.

[0027] Delete the acquired values ​​of the vibration signal acquisition unit and the mechanical condition assessment values ​​of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the mechanical condition matrix of the multistage centrifugal pump in the current monitoring period;

[0028] Delete the acquired values ​​of the ultrasonic signal acquisition unit and the sealing performance evaluation values ​​of the multi-stage centrifugal pump in the monitoring matrix of the multi-stage centrifugal pump in the current monitoring period, and obtain the sealing performance status matrix of the multi-stage centrifugal pump in the current monitoring period.

[0029] Delete the power acquisition unit's acquired value and the multistage centrifugal pump's energy efficiency evaluation value from the multistage centrifugal pump monitoring matrix for the current monitoring period, and obtain the multistage centrifugal pump's energy efficiency status matrix for the current monitoring period;

[0030] The alarm judgment unit compares the rank of the conveying capacity status matrix, head capacity status matrix, mechanical status matrix, sealing performance status matrix, and energy efficiency status matrix with the benchmark evaluation value of the corresponding status. If the rank of the conveying capacity status matrix, head capacity status matrix, mechanical status matrix, sealing performance status matrix, and energy efficiency status matrix is ​​greater than the benchmark evaluation value of the corresponding status, then the corresponding status is unqualified and an emergency alarm prompt is issued for the performance of the corresponding status. Otherwise, the overall operating status evaluation value of the multi-stage centrifugal pump is predicted.

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

[0032] Preferably, the overall operating status assessment value prediction unit includes:

[0033] The overall operating status assessment value determination subunit of the multi-stage centrifugal pump is used to calculate the rank of the multi-stage centrifugal pump monitoring matrix for the current monitoring period, which is used as the overall operating status assessment value of the multi-stage centrifugal pump for the current monitoring period.

[0034] Sub-unit for constructing the overall operating status assessment value prediction matrix of a multi-stage centrifugal pump: This sub-unit is used to construct the overall operating status assessment value prediction matrix of a multi-stage centrifugal pump based on the overall operating status assessment values ​​of the multi-stage centrifugal pump over several monitoring periods.

[0035] Among them, W i Let w1 be the overall operating status assessment value prediction matrix for the multi-stage centrifugal pump in the i-th monitoring period, w2 be the overall operating status assessment value for the multi-stage centrifugal pump in the first monitoring period, w3 be the overall operating status assessment value for the multi-stage centrifugal pump in the second monitoring period, and w4 be the overall operating status assessment value for the multi-stage centrifugal pump in the third monitoring period. i-1 w represents the overall operating status assessment value of the multi-stage centrifugal pump during the (i-1)th monitoring cycle. i This is the overall operating status assessment value of the multi-stage centrifugal pump in the i-th monitoring cycle;

[0036] The predicted value determination sub-unit obtains the mean of all matrix elements in the third column of the prediction matrix of the overall operating status evaluation value of the multi-stage 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 operating status evaluation value of the multi-stage centrifugal pump in the i-th monitoring period with the mean of all matrix elements in the third column to obtain a new matrix. The rank of the new matrix is ​​used as the overall operating status evaluation value of the multi-stage centrifugal pump in the (i+1)-th monitoring period.

[0037] The early warning judgment unit will issue an early warning if the overall operating status assessment value of the multi-stage centrifugal pump in the (i+1)th monitoring cycle is less than the preset overall operating status assessment value of the multi-stage centrifugal pump.

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

[0039] This invention, based on the existing conventional segmental multistage centrifugal pump, eliminates the original balancing mechanism and installs a sealing ring on the back of the last stage impeller. The end face of this sealing ring forms a sealing cavity with the end face of the discharge section bushing installed on the discharge section. This sealing cavity communicates with the suction cavity through the rear cavity of the discharge section. At the same time, a pair of single-row angular contact ball bearings are added to the outside of the cylindrical roller bearing at the non-drive end. After the pump starts, the axial force generated by the first N-1 stage impeller pointing towards the drive end is balanced by the axial force generated by the last stage impeller pointing towards the non-drive end due to the sealing ring on its back. 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. Attached Figure Description

[0040] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

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

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

[0043] In the diagram: 1. Pump coupling; 2. Pump shaft; 3. Shaft nut; 4. Perforated bearing end cover; 5. Cylindrical roller bearing; 6. Bearing retainer; 7. Bearing body A; 8. Shaft sleeve; 9. Stuffing gland; 10. Stuffing ring; 11. Suction section; 12. First-stage sealing ring; 13. First-stage impeller; 14. Guide vane; 15. Intermediate section; 16. Tie rod; 17. Balance water pipe assembly; 18. Impeller; 19. Guide vane sleeve; 20. Sealing ring; 21. Last-stage impeller; 22. Last-stage guide vane; 23. Last-stage impeller liner; 24. Discharge section; 25. Discharge section liner; 26. Stuffing box; 27. Bearing body B; 28. Water baffle ring; 29. ​​Bearing spacer; 30. Gasket; 31. Bearing bushing; 32. Bearing body water seal cover; 33. Angular contact ball bearing; 34. Holeless bearing end cover; 35. Round nut; 36. Anti-clogging and anti-wear component; 37. L-shaped anti-clogging and anti-wear component housing; 38. Conical adapter; 39. Filter screen 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-shaped guide groove; 49. Sand discharge auger; 50. Filter screen two; 51. Retriever claw. Detailed Implementation

[0044] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0045] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0046] The present invention provides the following embodiments.

[0047] Example 1

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

[0049] Preferably, the pump shaft 2 is equipped with a pump coupling 1 and a shaft nut 3 at the drive end. The shaft nut 3 is installed in the bearing housing 7. The cylindrical roller bearing 5 at the drive end of the pump shaft 2 is installed in the bearing housing 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 retainer 6 arranged in sequence.

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

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

[0052] The stuffing box 26 is equipped with a balance water pipe assembly 17, which is connected to 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-drive end of the pump shaft 2 are both installed inside the bearing housing 27. A water baffle ring 28 and a bearing spacer 29 are installed at the non-drive end of the pump shaft 2. A gasket 30 is installed at one end of the angular contact ball bearing 33. A bearing bushing 31 is provided outside the angular contact ball bearing 33. A non-perforated bearing end cap 34 and a round nut 35 are provided at the other end of the angular contact ball bearing 33.

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

[0055] The working principle and beneficial effects of the above technical solution are as follows: Based on the existing ordinary segmental multistage centrifugal pump, the original balancing mechanism is eliminated, and a sealing ring 20 is set on the back of the last stage impeller 21. The end face of the sealing ring 20 and the end face of the discharge section liner 25 installed on the discharge section 24 form a sealing cavity. The sealing cavity is connected to the suction cavity through the discharge section rear cavity. At the same time, a pair of single-row angular contact ball bearings 33 are added to the outside of the cylindrical roller bearing at the non-drive end. After the pump starts, the axial force generated by the first N-1 stage impeller pointing towards the drive end is balanced by the axial force generated by the last stage impeller 21 pointing towards the non-drive end due to the sealing ring 20 set on the back. 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 rotated through the pump coupling 1. 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. A certain vacuum is created at the suction port of the first impeller 13. Under the action of the suction liquid surface pressure, the liquid enters the pump through the suction section 11. After being thrown out of the first impeller 13, the liquid smoothly enters the forward guide vane in the same direction as the liquid flow velocity. It continues to flow outward along the forward guide vane, bypasses the internal partition plate of the guide vane 14 along the axial direction, and then flows inward along the reverse guide vane. It enters the next stage impeller 18 along the axial direction and finally is discharged from the discharge section 24 to the outlet pipe.

[0057] An adjustable sealing device, namely a sealing ring 20, is installed after the last stage impeller 21. The sealing cavity formed by the ring is connected to the suction section 11 through the balance water pipe assembly 17. When the pump is running, the first N-1 stage impeller generates an axial force pointing towards the drive end, and the last stage impeller 21 generates an axial force pointing towards the non-drive end, thereby automatically balancing the axial forces.

[0058] A set of cylindrical roller bearings 5 ​​is installed at both the drive end and the non-drive 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-drive end. The pair of bearings is installed in the bearing bushing 31. The bearing bushing 31 and the angular contact ball bearings 33 are clearance-fitted to ensure that the pair of bearings only bears the axial force.

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

[0060] Example 2

[0061] Based on Example 1, an anti-clogging and anti-wear component 36 is installed at the suction section 11. The anti-clogging and anti-wear component 36 includes an L-shaped anti-clogging and anti-wear component housing 37. The input end of the L-shaped anti-clogging and anti-wear component housing 37 is an inclined end face and is provided with a filter screen 39. The output end is bolted to a conical adapter 38. 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 inside the L-shaped anti-clogging and anti-wear component housing 37. A filter screen 50 is provided at the inlet of the large impurity collection chamber 40. A claw 51 is rotatably connected behind the filter screen 50.

[0062] A guide rod 41 is fixedly connected inside the large impurity collection chamber 40. A pressure plate 42 is slidably connected to the guide rod 41. The top of the pressure plate 42 is connected to the inner wall of the large impurity collection chamber 40 through an elastic element. 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 collection chamber 40. A negative pressure impeller 46 is rotatably connected inside the large impurity collection chamber 40. A drainage net 47 is provided behind the negative pressure impeller 46. A fine sand arc-shaped guide groove 48 is provided at the opposite position of the drainage net 47 on the inner wall of the L-shaped anti-blocking and anti-wear component housing 37. A sand discharge auger 49 is rotatably connected inside the fine sand arc-shaped guide groove 48.

[0063] The working principle and beneficial effects of the above technical solution are as follows: After entering the L-shaped anti-clogging and anti-wear component housing 37, silt and large impurities are first filtered by the filter screen 39. When the large impurities move to the claw 51, the claw 51 rotates and drives them to the inlet of the large impurity collection chamber 40. Under 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 flow out from the drain screen 47. The water flow discharged from the drain screen 47 forms resistance to the water flow entering the L-shaped anti-clogging and anti-wear component housing 37. The silt in the water flow entering the L-shaped anti-clogging and anti-wear component housing 37 is discharged onto the fine sand arc guide groove 48 under the action of resistance. After accumulation, it is finally discharged through the sand discharge auger 49. 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 is insufficient to draw large impurities into the large impurity collection chamber 40, the electric winding wheel 44 rotates and pulls the steel rope 43, causing the pressure plate 42 to move downward and press the large impurities from the inlet of the large impurity collection chamber 40 into the large impurity collection chamber 40.

[0065] Example 3

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

[0067] The data acquisition time determination module is used to determine several data acquisition times for the current monitoring period based on the current monitoring period.

[0068] The data acquisition module is used to acquire data at several data acquisition points based on the current monitoring period, including:

[0069] Flow acquisition unit for flow acquisition in suction section 11 and discharge section 24, pressure acquisition unit for pressure acquisition in suction section 11 and discharge section 24, vibration signal acquisition unit for vibration signal acquisition in multi-stage centrifugal pump, ultrasonic signal acquisition unit for ultrasonic signal acquisition in multi-stage centrifugal pump, and power acquisition unit for power acquisition in multi-stage centrifugal pump.

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

[0071] The monitoring matrix construction module is used to determine the evaluation values ​​obtained at several data acquisition moments in the current monitoring period of the data acquisition module based on several data acquisition values ​​and performance evaluation values ​​collected at several data acquisition moments in the current monitoring period of the data acquisition module, and to construct the multi-stage centrifugal pump monitoring matrix for the current monitoring period.

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

[0073] Preferably, the flow acquisition unit, pressure acquisition unit, vibration signal acquisition unit, ultrasonic signal acquisition unit, and power acquisition unit use flow sensors, pressure sensors, vibration sensors, ultrasonic sensors, and power sensors, respectively, to acquire data.

[0074] Preferably, the trained multi-stage centrifugal pump delivery capacity evaluation model is a model obtained by pre-training a large amount of flow data collected from the suction section 11 and the discharge section 24 as model inputs and using the multi-stage centrifugal pump delivery capacity evaluation values ​​corresponding to the flow data collected from the suction section 11 and the discharge section 24 as model outputs, and then training the model with a neural network.

[0075] The trained multistage centrifugal pump head capacity assessment model is obtained by using the pressure data collected in the suction section 11 and the discharge section 24 as the model input and the multistage centrifugal pump head capacity assessment values ​​corresponding to the pressure data collected in the suction section 11 and the discharge section 24 as the model output, and then training the model with a neural network.

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

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

[0078] The trained multi-stage centrifugal pump energy efficiency evaluation model is obtained by using multi-stage centrifugal pump power acquisition data as the model input and multi-stage centrifugal pump energy efficiency evaluation values ​​corresponding to the multi-stage centrifugal pump power acquisition data as the model output, and then training the model through a neural network.

[0079] The working principle and beneficial effects of the above technical solution are as follows: The data acquisition module can collect multiple key data points at different times within the current monitoring period, including flow rate, pressure, vibration signals, ultrasonic signals, and power. This data provides detailed information on the pump's operating status. The collected data is input into a trained evaluation model to assess the pump's delivery capacity, head capacity, mechanical condition, sealing performance, and energy efficiency. These evaluation values ​​can serve as indicators of the pump's operating 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 period. The matrix structure facilitates analysis and comparison. Based on the monitoring matrix, the multi-stage centrifugal pump operating status analysis module analyzes and judges the pump's delivery capacity, head capacity, mechanical condition, sealing performance, and energy efficiency. When an unqualified status is detected, the system will promptly issue an emergency alarm, reminding operators to inspect and maintain the pump. When all statuses are qualified, the multi-stage centrifugal pump operating status analysis module can also predict the overall operating status of the pump based on the analysis results, providing early warnings of the pump's overall performance and guidance for maintenance and upkeep.

[0080] Example 4

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

[0082] in, Let a be the multi-stage centrifugal pump monitoring matrix for the i-th monitoring cycle. i1 a is the flow difference between the inhalation section 11 and the discharge section 24 collected by the flow acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 a is the flow difference between the inhalation section 11 and the discharge section 24 collected by the flow acquisition unit at the second data acquisition time of the i-th monitoring cycle. in b is the flow difference between the inhalation section 11 and the discharge section 24 collected by the flow acquisition unit at the nth data acquisition time of the i-th monitoring cycle. i1 b is the pressure difference between the inhalation section 11 and the exhalation section 24 collected by the pressure acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 b is the pressure difference between the inhalation section 11 and the exhalation section 24 collected by the pressure acquisition unit at the second data acquisition time of the i-th monitoring cycle. in c represents the pressure difference between the inhalation section 11 and the exhalation section 24 collected by the pressure acquisition unit at the nth data acquisition time of the i-th monitoring cycle. i1 Let c be the vibration velocity collected by the vibration signal acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2Let c be the vibration velocity collected by the vibration signal acquisition unit at the second data acquisition time of the i-th monitoring cycle. in Let d be the vibration velocity collected by the vibration signal acquisition unit at the nth data acquisition time of the i-th monitoring cycle. i1 Let d be the sound pressure level value acquired by the ultrasonic signal acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 Let d be the sound pressure level value acquired by the ultrasonic signal acquisition unit at the second data acquisition time of the i-th monitoring cycle. in e represents the sound pressure level value acquired by the ultrasonic signal acquisition unit at the nth data acquisition time in the i-th monitoring cycle. i1 e represents the power value acquired by the power acquisition unit at the first data acquisition time of the i-th monitoring cycle. i2 e represents the power value acquired by the power acquisition unit at the second data acquisition time of the i-th monitoring cycle. in Let A be the power value collected by the power acquisition unit at the nth data acquisition time of the i-th monitoring cycle. i1 Let A be the evaluation value of the multi-stage centrifugal pump's delivery capacity at the first data acquisition time of the i-th monitoring cycle. i2 Let A be the evaluation value of the multi-stage centrifugal pump's delivery capacity at the second data acquisition time of the i-th monitoring cycle. in B is the evaluation value of the multi-stage centrifugal pump's delivery capacity at the nth data acquisition time in the i-th monitoring period. i1 B represents the head capacity assessment value of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2 B represents the head capacity assessment value of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. in C represents the head capacity assessment value of the multi-stage centrifugal pump at the nth data acquisition time in the i-th monitoring cycle. i1 C represents the mechanical condition assessment value of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2 C represents the mechanical condition assessment value of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. in D represents the mechanical condition assessment value of the multi-stage centrifugal pump at the nth data acquisition time in the i-th monitoring cycle. i1 D represents the evaluation value of the sealing performance of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2 D represents the evaluation value of the sealing performance of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. in E represents the evaluation value of the sealing performance of the multi-stage centrifugal pump at the nth data acquisition time in the i-th monitoring cycle. i1 E represents the energy efficiency assessment value of the multi-stage centrifugal pump at the first data acquisition time of the i-th monitoring cycle. i2 E represents the energy efficiency assessment value of the multi-stage centrifugal pump at the second data acquisition time of the i-th monitoring cycle. inThe value is the energy efficiency assessment value of the multi-stage centrifugal pump at the nth data acquisition time in the i-th monitoring cycle.

[0083] The working principle and beneficial effects of the above technical solution are as follows: The multi-stage centrifugal pump monitoring matrix includes parameters such as the flow difference between the suction section 11 and the discharge section 24, the pressure difference between the suction section 11 and the discharge section 24, vibration velocity, sound pressure level, and power value at several data acquisition times. 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 multi-stage centrifugal pump delivery capacity assessment value, multi-stage centrifugal pump head capacity assessment value, multi-stage centrifugal pump mechanical condition assessment value, multi-stage centrifugal pump sealing performance assessment value, and multi-stage centrifugal pump energy efficiency assessment value at several data acquisition times. It can intuitively display the pump's performance indicators and assessment results, which is convenient for further analysis and judgment. Selecting several data acquisition times 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 multi-stage centrifugal pumps in the current monitoring period, based on the multi-stage centrifugal pump monitoring matrix of the current monitoring period.

[0087] Delete the collected values ​​of the flow acquisition unit and the multi-stage centrifugal pump delivery capacity evaluation values ​​in the multi-stage centrifugal pump monitoring matrix for the current monitoring period, and obtain the delivery capacity status matrix of the multi-stage centrifugal pump for the current monitoring period.

[0088] Delete the collected values ​​of the pressure acquisition unit and the head capacity evaluation value of the multi-stage centrifugal pump in the monitoring matrix of the current monitoring period, and obtain the head capacity status matrix of the multi-stage centrifugal pump in the current monitoring period.

[0089] Delete the acquired values ​​of the vibration signal acquisition unit and the mechanical condition assessment values ​​of the multistage centrifugal pump in the monitoring matrix of the multistage centrifugal pump in the current monitoring period, and obtain the mechanical condition matrix of the multistage centrifugal pump in the current monitoring period;

[0090] Delete the acquired values ​​of the ultrasonic signal acquisition unit and the sealing performance evaluation values ​​of the multi-stage centrifugal pump in the monitoring matrix of the multi-stage centrifugal pump in the current monitoring period, and obtain the sealing performance status matrix of the multi-stage centrifugal pump in the current monitoring period.

[0091] Delete the power acquisition unit's acquired value and the multistage centrifugal pump's energy efficiency evaluation value from the multistage centrifugal pump monitoring matrix for the current monitoring period, and obtain the multistage centrifugal pump's energy efficiency status matrix for the current monitoring period;

[0092] The alarm judgment unit compares the rank of the conveying capacity status matrix, head capacity status matrix, mechanical status matrix, sealing performance status matrix, and energy efficiency status matrix with the benchmark evaluation value of the corresponding status. If the rank of the conveying capacity status matrix, head capacity status matrix, mechanical status matrix, sealing performance status matrix, and energy efficiency status matrix is ​​greater than the benchmark evaluation value of the corresponding status, then the corresponding status is unqualified and an emergency alarm prompt is issued for the performance of the corresponding status. Otherwise, the overall operating status evaluation value of the multi-stage centrifugal pump is predicted.

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

[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 cycle, the conveying capacity status matrix, head capacity status matrix, mechanical status matrix, sealing performance status matrix, and energy efficiency status matrix of the multi-stage centrifugal pump in the current monitoring cycle are obtained. The alarm judgment unit compares the rank of the conveying capacity status matrix, head capacity status matrix, mechanical status matrix, sealing performance status matrix, and energy efficiency status matrix with the benchmark evaluation value of the corresponding state. If the rank of these matrices is greater than the benchmark evaluation value of the corresponding state, it indicates that the state is unqualified, and the system will issue an emergency alarm prompt. This helps staff to accurately locate and quickly identify the problem and take corresponding measures. If all are qualified, the overall operating status evaluation value of the multi-stage centrifugal pump in the next monitoring cycle is predicted, and the system determines whether to issue an overall performance warning prompt for the multi-stage centrifugal pump based on the prediction result. The alarm prompt ensures timely repair of unqualified states, and the warning prompt can avoid alarm prompts in the next monitoring cycle. Prevention is better than repair, which can greatly reduce the economic losses caused by centrifugal pump failures, reduce downtime and maintenance costs, and help improve the service life of centrifugal pumps.

[0095] Example 6

[0096] Based on Example 5, the overall operating status evaluation value prediction unit includes:

[0097] The overall operating status assessment value determination subunit of the multi-stage centrifugal pump is used to calculate the rank of the multi-stage centrifugal pump monitoring matrix for the current monitoring period, which is used as the overall operating status assessment value of the multi-stage centrifugal pump for the current monitoring period.

[0098] Sub-unit for constructing the overall operating status assessment value prediction matrix of a multi-stage centrifugal pump: This sub-unit is used to construct the overall operating status assessment value prediction matrix of a multi-stage centrifugal pump based on the overall operating status assessment values ​​of the multi-stage centrifugal pump over several monitoring periods.

[0099] Among them, W i Let w1 be the overall operating status assessment value prediction matrix for the multi-stage centrifugal pump in the i-th monitoring period, w2 be the overall operating status assessment value for the multi-stage centrifugal pump in the first monitoring period, w3 be the overall operating status assessment value for the multi-stage centrifugal pump in the second monitoring period, and w4 be the overall operating status assessment value for the multi-stage centrifugal pump in the third monitoring period. i-1 w represents the overall operating status assessment value of the multi-stage centrifugal pump during the (i-1)th monitoring cycle. i This is the overall operating status assessment value of the multi-stage centrifugal pump in the i-th monitoring cycle;

[0100] The predicted value determination sub-unit obtains the mean of all matrix elements in the third column of the prediction matrix of the overall operating status evaluation value of the multi-stage 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 operating status evaluation value of the multi-stage centrifugal pump in the i-th monitoring period with the mean of all matrix elements in the third column to obtain a new matrix. The rank of the new matrix is ​​used as the overall operating status evaluation value of the multi-stage centrifugal pump in the (i+1)-th monitoring period.

[0101] The early warning judgment unit will issue an early warning if the overall operating status assessment value of the multi-stage centrifugal pump in the (i+1)th monitoring cycle is less than the preset overall operating status assessment 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 multi-stage centrifugal pump monitoring matrix for the current monitoring period, the rank is used as the overall operating status assessment value of the multi-stage centrifugal pump for the current monitoring period. The rank reflects the correlation and trend of various 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 sudden changes and fluctuations in the data can be reduced, which helps to remove the influence of noise and outliers and improve the reliability and stability of the assessment value. Due to the accumulation of transmission errors of the assessment value, the value in the third row of the prediction matrix may deviate significantly from the actual situation. By replacing the value in the third row with the mean of the third column, the error transmission can be reduced, and the overall operating status of the next period can be predicted more accurately. After calculating the mean in the third column, applying it to the third row can balance the influence of different assessment values ​​in the overall operating status assessment matrix, maintain a comprehensive consideration of the overall operating status assessment, and avoid the excessive influence of a certain assessment value on the prediction result.

[0103] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A multi-stage centrifugal pump monitoring system for monitoring a multi-stage centrifugal pump, the system comprising: The multistage centrifugal pump comprises a pump shaft (2), a cylindrical roller bearing (5) is installed on the driving end and the non-driving end of the pump shaft (2), a pair of single-row angular contact ball bearings (33) are installed on the non-driving end of the pump shaft (2), the pump shaft (2) is provided with a first-stage impeller (13), an impeller (18) and a last-stage impeller (21), the first-stage impeller (13), the impeller (18) and the last-stage impeller (21) are respectively located in a suction section (11), a middle section (15) and a discharge section (24), the end face of the last-stage impeller (21) is provided with a sealing ring (20), the discharge section (24) is provided with a discharge section lining ring (25), 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 the sealing cavity is communicated with the suction section (11) through the rear cavity of the discharge section (24); The suction section (11) is provided with an anti-blocking and anti-abrasion assembly (36), the anti-blocking and anti-abrasion assembly (36) comprises an L-shaped anti-blocking and anti-abrasion assembly shell (37), the input end of the L-shaped anti-blocking and anti-abrasion assembly shell (37) is an inclined end face, and is provided with a filter screen one (39), the output end of the L-shaped anti-blocking and anti-abrasion assembly shell (37) is bolt-connected with a conical adapter (38), the conical adapter (38) is used for cooperating with the inner wall of the suction section (11), the L-shaped anti-blocking and anti-abrasion assembly shell (37) is provided with a large impurity collecting cavity (40) therein, the large impurity collecting cavity (40) is provided with a filter screen two (50) at the inlet, and the rear of the filter screen two (50) is rotatably connected with a fishing claw (51); The large impurity collecting cavity (40) is fixedly connected with a guide rod (41), the guide rod (41) is slidably connected with a pressing plate (42) in the up-down direction, the top of the pressing plate (42) is connected with the inner wall of the large impurity collecting cavity (40) through an elastic element, the bottom of the pressing plate (42) is fixedly connected with a steel wire (43), the other end of the steel wire (43) is wound on an electric winding wheel (44), the large impurity collecting cavity (40) is rotatably connected with a linkage closing plate (45), the large impurity collecting cavity (40) is rotatably connected with a negative pressure impeller (46), the rear of the negative pressure impeller (46) is provided with a drainage screen (47), the drainage screen (47) is provided with a fine sand arc-shaped guide groove (48) at the position opposite to the inner wall of the L-shaped anti-blocking and anti-abrasion assembly shell (37), and the fine sand arc-shaped guide groove (48) is rotatably connected with a sand auger (49); The multistage centrifugal pump monitoring system comprises: A data acquisition time determination module configured to determine a plurality of data acquisition times of a current monitoring period based on the current monitoring period; A data acquisition module configured to perform data acquisition based on the plurality of data acquisition times of the current monitoring period, comprising: A flow acquisition unit configured to acquire flow of the suction section (11) and the discharge section (24), a pressure acquisition unit configured to acquire pressure of the suction section (11) and the discharge section (24), a vibration signal acquisition unit configured to acquire vibration signals of the multistage centrifugal pump, an ultrasonic signal acquisition unit configured to acquire ultrasonic signals of the multistage centrifugal pump, and a power acquisition unit configured to acquire power of the multistage centrifugal pump. The performance evaluation value determination module is configured 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 the plurality of data collection time points into the trained multi-stage centrifugal pump conveying 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 conveying 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 the plurality of data collection time points; The monitoring matrix construction module is configured to construct a multi-stage centrifugal pump monitoring matrix of the current monitoring period based on the plurality of data collection values collected at the plurality of data collection time points of the current monitoring period by the data collection module and the plurality of evaluation values obtained at the plurality of data collection time points of the current monitoring period by the performance evaluation value determination module; The multi-stage centrifugal pump running state analysis module is configured to analyze the conveying capacity state, the head capacity state, the mechanical state, the sealing performance state, and the energy efficiency state of the multi-stage centrifugal pump based on the multi-stage centrifugal pump monitoring matrix of the current monitoring period, and perform emergency alarm prompts for the corresponding state performance or overall running state evaluation value prediction of the multi-stage centrifugal pump based on the analysis result, and perform multi-stage centrifugal pump overall performance early warning prompts based on the prediction result.

2. A multi-stage centrifugal pump monitoring system according to claim 1, wherein: The driving end of the pump shaft (2) is provided with a pump coupling (1) and a shaft nut (3), the shaft nut (3) is installed in a bearing body A (7), the cylindrical roller bearing (5) at the driving end of the pump shaft (2) is installed in the bearing body A (7), one end of the cylindrical roller bearing (5) is provided with a hole bearing end cover (4), and the other end surface of the cylindrical roller bearing (5) is provided with a bearing baffle sleeve (6) in sequence.

3. A multi-stage centrifugal pump monitoring system according to claim 1, wherein: The pump shaft (2) is provided with a shaft sleeve (8), a packing gland (9) and a packing ring (10) in sequence at the suction section (11); The discharge section (24) is provided with a packing box body (26) behind, the bearing body A (7) is installed in front of the packing ring (10), and the bearing body B (27) is installed behind the packing box body (26); The packing box body (26) is provided with a balance water pipe assembly (17), and the balance water pipe assembly (17) is communicated with the suction section (11) and the discharge section (24).

4. A multi-stage centrifugal pump monitoring system according to claim 3, wherein: The cylindrical roller bearing (5) and the single row 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 provided with a water baffle ring (28) and a bearing spacer sleeve (29), one end of the single row angular contact ball bearing (33) is provided with a gasket (30), the single row angular contact ball bearing (33) is provided with a bearing bushing (31) outside, and the other end of the single row angular contact ball bearing (33) is provided with a holeless bearing end cover (34) and a round nut (35).

5. The multi-stage centrifugal pump monitoring system of claim 1, wherein: The first-stage impeller (13) is provided with a first-stage sealing ring (12) on the end surface, the impeller (18) is provided with a guide vane (14) outside, the guide vane (14) is provided with a guide vane sleeve (19) outside, and the last-stage impeller (21) is provided with a last-stage guide vane (22) outside.

6. The multi-stage centrifugal pump monitoring system of claim 1, wherein: The monitoring matrix construction module constructs the multi-stage centrifugal pump monitoring matrix of the current monitoring period, which includes: （1）； Wherein, is the monitoring matrix of the multi-stage centrifugal pump for the i-th monitoring period, 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 time for the i-th monitoring period, 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 for the i-th monitoring period, is the flow difference between the suction section (11) and the discharge section (24) collected by the flow collection unit at the n-th data collection time for the i-th monitoring period, 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 time for the i-th monitoring period, 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 time for the i-th monitoring period, is the pressure difference between the suction section (11) and the discharge section (24) collected by the pressure collection unit at the n-th data collection time for the i-th monitoring period, is the vibration velocity collected by the vibration signal collection unit at the first data collection time for the i-th monitoring period, is the vibration velocity collected by the vibration signal collection unit at the second data collection time for the i-th monitoring period, is the vibration velocity collected by the vibration signal collection unit at the n-th data collection time for the i-th monitoring period, is the sound pressure level value collected by the ultrasonic signal collection unit at the first data collection time for the i-th monitoring period, is the sound pressure level value collected by the ultrasonic signal collection unit at the second data collection time for the i-th monitoring period, is the sound pressure level value collected by the ultrasonic signal collection unit at the n-th data collection time for the i-th monitoring period, is the power value collected by the power collection unit at the first data collection time for the i-th monitoring period, is the power value collected by the power collection unit at the second data collection time for the i-th monitoring period, is the power value collected by the power collection unit at the n-th data collection time for the i-th monitoring period, is the multi-stage centrifugal pump conveying capacity evaluation value at the first data collection time for the i-th monitoring period, is the multi-stage centrifugal pump conveying capacity evaluation value at the second data collection time for the i-th monitoring period, is the multi-stage centrifugal pump conveying capacity evaluation value at the n-th data collection time for the i-th monitoring period, is the multi-stage centrifugal pump head capacity evaluation value at the first data collection time for the i-th monitoring period, The head capacity evaluation value of the multistage centrifugal pump at the second data collection moment of the i th monitoring period, The head capacity evaluation value of the multistage centrifugal pump at the n th data collection moment of the i th monitoring period, The mechanical state evaluation value of the multistage centrifugal pump at the first data collection moment of the i th monitoring period, The mechanical state evaluation value of the multistage centrifugal pump at the second data collection moment of the i th monitoring period, The mechanical state evaluation value of the multistage centrifugal pump at the n th data collection moment of the i th monitoring period, The sealing performance evaluation value of the multistage centrifugal pump at the first data collection moment of the i th monitoring period, The sealing performance evaluation value of the multistage centrifugal pump at the second data collection moment of the i th monitoring period, The sealing performance evaluation value of the multistage centrifugal pump at the n th data collection moment of the i th monitoring period, The energy efficiency evaluation value of the multistage centrifugal pump at the first data collection moment of the i th monitoring period, The energy efficiency evaluation value of the multistage centrifugal pump at the second data collection moment of the i th monitoring period, The energy efficiency evaluation value of the multistage centrifugal pump at the n th data collection moment of the i th monitoring period.

7. The multi-stage centrifugal pump monitoring system of claim 1, wherein: The multi-stage centrifugal pump running state analysis module comprises: The traversal analysis unit is configured to: obtain, based on the multi-stage centrifugal pump monitoring matrix of the current monitoring period, a conveying capacity state matrix, a head capacity state matrix, a mechanical state matrix, a sealing performance state matrix and an energy efficiency state matrix of the multi-stage centrifugal pump of the current monitoring period; delete the collection value of the flow collection unit and the multi-stage centrifugal pump conveying capacity evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period to obtain the conveying capacity state matrix of the multi-stage centrifugal pump of the current monitoring period; delete the collection value of the pressure collection unit and the multi-stage centrifugal pump head capacity evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period to obtain the head capacity state matrix of the multi-stage centrifugal pump of the current monitoring period; delete the collection value of the vibration signal collection unit and the multi-stage centrifugal pump mechanical state evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period to obtain the mechanical state matrix of the multi-stage centrifugal pump of the current monitoring period; delete the collection value of the ultrasonic signal collection unit and the multi-stage centrifugal pump sealing performance evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period to obtain the sealing performance state matrix of the multi-stage centrifugal pump of the current monitoring period; delete the collection value of the power collection unit and the multi-stage centrifugal pump energy efficiency evaluation value in the multi-stage centrifugal pump monitoring matrix of the current monitoring period to obtain the energy efficiency state matrix of the multi-stage centrifugal pump of the current monitoring period; The alarm judgment unit is configured to: compare 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 corresponding state reference evaluation values; if 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 are greater than the corresponding state reference evaluation values, the corresponding state is unqualified, and an urgent alarm prompt of the corresponding state performance is performed; otherwise, an overall running state evaluation value of the multi-stage centrifugal pump is predicted. The overall running state evaluation value prediction unit is configured to: predict the overall running state evaluation value of the multi-stage centrifugal pump of the next monitoring period, and judge whether to perform a multi-stage centrifugal pump overall performance early warning prompt based on the prediction result.

8. A multi-stage centrifugal pump monitoring system according to claim 7, wherein: The overall running state evaluation value prediction unit comprises: The overall running state evaluation value determination subunit of the multi-stage centrifugal pump is configured to: calculate the rank of the multi-stage centrifugal pump monitoring matrix of the current monitoring period as the overall running state evaluation value of the multi-stage centrifugal pump of the current monitoring period; The overall running state evaluation value prediction matrix construction subunit of the multi-stage centrifugal pump is configured to: construct the overall running state evaluation value prediction matrix of the multi-stage centrifugal pump based on the overall running state evaluation values of the multi-stage centrifugal pump of a plurality of monitoring periods; （2） wherein, is the overall running state evaluation value prediction matrix of the multistage centrifugal pump in the i th monitoring period, is the overall running state evaluation value of the multistage centrifugal pump in the 1 st monitoring period, is the overall running state evaluation value of the multistage centrifugal pump in the 2 nd monitoring period, is the overall running state evaluation value of the multistage centrifugal pump in the 3 rd monitoring period, is the overall running state evaluation value of the multistage centrifugal pump in the i-1 th monitoring period, is the overall running state evaluation value of the multistage centrifugal pump in the i th monitoring period; The prediction value determination subunit is configured to: obtain the mean value of all matrix elements in the third column of the overall running state evaluation value prediction matrix of the i th monitoring period multi-stage centrifugal pump, and replace the values of all matrix elements in the third row of the overall running state evaluation value prediction matrix of the i th monitoring period multi-stage centrifugal pump with the mean value of all matrix elements in the third column to obtain a new matrix, and take the rank of the new matrix as the overall running state evaluation value of the i+1 th monitoring period multi-stage centrifugal pump. The early warning judging unit performs early warning prompt if the overall operation state evaluation value of the multi-stage centrifugal pump in the i+1th monitoring period is less than the preset overall operation state evaluation value of the multi-stage centrifugal pump.

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