Modularized multi-stage centrifugal pump

Abstract

The invention provides a modularized multi-stage centrifugal pump which comprises an end cover, a plurality of modularized assemblies and a volute, the modularized assemblies are sequentially connected end to end, each modularized assembly comprises a shell, an impeller and a motor module, and a containing space is formed in the shell; a containing space is formed in the shell, a suction inlet is formed in the shell in the axial direction of the containing space, a discharge outlet is formed in the shell in the radial direction of the containing space, the impeller is rotatably arranged in the containing space, the motor module comprises a stator and a permanent magnet, the stator is fixed in the shell, and the permanent magnet is fixed to the impeller; the axial magnetic flux motor is adopted as a driving motor of the centrifugal pump, the motor and the centrifugal pump are integrated, the axial space is compressed, a shaft seal device and a coupler which are prone to damage of a traditional centrifugal pump are omitted, the sealing performance of the centrifugal pump is improved, in addition, the stage number of the pump can be adjusted by increasing or decreasing the number of modular assemblies, and the service life of the pump is prolonged. Different flow lift requirements are met; the problems that in the prior art, the axial size is large, shaft seal leakage is prone to occurring, the stage number is fixed, and adaptability is poor are solved.

Description

A modular multistage centrifugal pump Technical Field

[0001] This invention relates to the field of speed reducer equipment, and more particularly to a modular multistage centrifugal pump. Background Technology

[0002] Multistage centrifugal pumps are important fluid transport equipment in the fields of shipbuilding and aviation. Currently, multistage centrifugal pumps generally use motor-driven impellers to operate.

[0003] Patent CN 120159777 A discloses an energy-saving multi-stage centrifugal pump with adjustable stages, including a pump casing. The front of the pump casing has an outlet, and the top of the pump casing has an inlet. The inlet is used to introduce liquid into the interior of the pump casing, where it is centrifugally pressurized and discharged from the outlet. A drive motor for the main shaft is also installed on one side of the pump casing. Pump covers are wrapped around both sides of the pump casing. A pressure sensor is also provided on the outer surface of the pump casing. A dual pressure relief assembly is embedded inside the pump casing, and the dual pressure relief assembly includes an inner pump body.

[0004] However, the above technology has the following problems: although it can adapt to pressure changes by changing the number of stages, this motor-driven impeller method has low axial space utilization and is complicated to replace. Summary of the Invention

[0005] In view of this, it is necessary to provide a modular multistage centrifugal pump that can solve the problems of low axial space utilization and complex replacement in the existing technology.

[0006] This invention provides a modular multistage centrifugal pump, comprising: an end cover, multiple modular components, wherein the modular component at the first end is connected to the end cover, and the modular component at the last end is connected to a volute. Each modular component includes a housing, an impeller, and a motor module. The housing forms an accommodating space, and the housing has an axial suction port and a radial discharge port. The impeller is rotatably disposed within the accommodating space. The motor module includes a stator and a permanent magnet. The stator is fixed within the housing, and the permanent magnet is fixed to the impeller. The volute is also present. The discharge port of the last modular component is connected to the discharge port of the volute. The suction port of the modular component is connected to the discharge port of the preceding modular component, and the suction port of the first modular component is connected to the inlet of the end cover.

[0007] In other embodiments, an impeller inlet is provided at the center of the impeller axis, an impeller outlet is provided circumferentially on the impeller, and a cavity is formed inside the impeller that connects the impeller inlet and the impeller outlet.

[0008] In other embodiments, the stator includes an iron core and a stator winding, the iron core being annular and the stator winding being disposed on the iron core.

[0009] In other embodiments, the iron core has a pin hole with a pin inside to restrict the stator winding from moving around in the circumferential direction.

[0010] In other embodiments, the permanent magnets are provided on both ends of the impeller, and the motor module includes two stators, which correspond to the two ends of the impeller respectively.

[0011] In other embodiments, the modular component further includes a front guide vane section and a rear guide vane section. The front guide vane section is located at the front end of the impeller along the water flow direction and is fixed to the inner wall of the housing. The rear guide vane section is located at the rear end of the impeller along the water flow direction and is fixed to the inner wall of the housing. The two stators are respectively fixed on the front guide vane section and the rear guide vane section.

[0012] In other embodiments, the front guide vane section has a liquid inlet in the middle, the rear guide vane section has a liquid outlet in the middle, the front guide vane section and the rear guide vane section are provided with closed annular grooves, the stator is embedded in the annular grooves, and the annular grooves are provided with annular sealing caps.

[0013] In other embodiments, a rotating bearing is provided at the liquid inlet of the front guide vane and the liquid outlet of the rear guide vane. The rotating bearing has a first rotating end and a second rotating end that can rotate relative to each other. The first rotating end is fixed to the front guide vane section or the rear guide vane section, and the second rotating end is fixed to the impeller.

[0014] In other embodiments, the volute includes a volute body, a tail impeller, and a tail impeller drive assembly. The drain port is located circumferentially on the volute body and tangentially along the end face of the volute body. The tail impeller is rotatably located inside the volute body and coaxially arranged with the volute body. The tail impeller drive assembly is used to drive the tail impeller to rotate relative to the volute body.

[0015] In other embodiments, a temperature control module is also included, comprising a temperature sensor, a flow and pressure sensor, a controller, and a power supply unit. The temperature sensor is located at the stator and the tail impeller drive assembly to monitor the operating temperature of the stator and the tail impeller drive assembly in real time. The flow and pressure sensor is located at the suction port, the discharge port, the liquid inlet, and the liquid outlet to monitor the flow rate and pressure at the suction port, the discharge port, the liquid inlet, and the liquid outlet. The power supply unit is used for electrical connection to the stator and the tail impeller drive assembly. The controller is electrically connected to the temperature sensor, the flow and pressure sensor, and the power supply unit. The controller controls the power supply unit based on the temperature detected by the temperature sensor and the flow rate and pressure monitored by the flow and pressure sensor.

[0016] The beneficial effects of this invention are as follows: This invention provides a modular multistage centrifugal pump, including an end cover, multiple modular components, and a volute. The multiple modular components are connected end-to-end sequentially. The modular component at the first end is connected to the end cover, and the modular component at the last end is connected to the volute. Each modular component includes a housing, an impeller, and a motor module. A receiving space is formed within the housing. An inlet is axially formed along the receiving space, and an outlet is radially formed along the receiving space. The impeller is rotatably disposed within the receiving space. The motor module is fixed within the receiving space and drives the impeller to rotate relative to the receiving space. The motor module includes... The invention includes a stator and a permanent magnet. The stator is fixed inside the housing, and the permanent magnet is fixed on the impeller. The suction port of the modular component is connected to the discharge port of the preceding modular component. The suction port of the first modular component is connected to the liquid inlet of the end cover, and the discharge port of the last modular component is connected to the liquid outlet of the volute. This invention uses an axial flux motor as the drive motor for the centrifugal pump. Compared to existing solutions, this integration of the motor and centrifugal pump greatly reduces the axial space occupied by the pump body. This invention eliminates the easily damaged shaft seal device and coupling of traditional centrifugal pumps, improving the sealing performance of the centrifugal pump. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 is a structural schematic diagram of the modular multistage centrifugal pump of the present invention; Figure 2 is a cross-sectional schematic diagram of the modular multistage centrifugal pump of the present invention; Figure 3 is an exploded schematic diagram of the internal structure of the modular multistage centrifugal pump of the present invention; Figure 4 is a structural schematic diagram of the stator in Figure 2; Figure 5 is a modular schematic diagram of the temperature control module in the modular multistage centrifugal pump of the present invention; Figure 6 is a flow chart of the temperature control module in the modular multistage centrifugal pump of the present invention; wherein: 1-end cover, 11-inlet, 2-modular component, 21-shell, 211-suction port, 212-discharge port, 22-impeller, 221-impeller inlet, 222-impeller inlet, 222-impeller-driven ... 2-Impeller outlet, 23-Motor module, 231-Stator, 231a-Iron core, 231b-Stator winding, 231c-Pin hole, 232-Permanent magnet, 24-Front guide vane section, 25-Rear guide vane section, 26-Annular groove, 27-Annular sealing cover, 28-Rotating bearing, 3-Volume housing, 31-Drain outlet, 32-Volume housing body, 33-Tail impeller, 34-Tail impeller drive assembly, 341-Tail impeller stator, 342-Tail impeller permanent magnet, 4-Fixing screw, 5-Temperature control module, 51-Temperature sensor, 52-Flow and pressure sensor, 53-Controller, 54-Power supply unit. Detailed Implementation

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0020] To address the aforementioned technical problems, embodiments of the present invention provide a modular multistage centrifugal pump, comprising an end cover 1, multiple modular components 2, and a volute 3. The multiple modular components 2 employ an axial flux motor as the drive motor for the centrifugal pump. Compared to existing solutions, this integration of the motor and the centrifugal pump significantly reduces the axial space occupied by the pump body itself. The present invention eliminates the easily damaged shaft seal device and coupling of traditional centrifugal pumps, thereby improving the sealing performance of the centrifugal pump.

[0021] Please refer to Figures 1-5, which illustrate a modular multistage centrifugal pump according to an embodiment of the present invention. The pump includes: an end cover 1, multiple modular components 2, and a volute 3. The multiple modular components 2 are connected end-to-end sequentially. The modular component 2 at the first end is connected to the end cover 1, and the modular component 2 at the last end is connected to the volute 3. Each modular component 2 includes a housing 21, an impeller 22, and a motor module 23. A receiving space is formed within the housing 21. A suction port 211 is provided on the housing 21 along the axial direction of the receiving space, and a radial direction of the receiving space is also provided. The assembly has an outlet 212. The impeller 22 is rotatably disposed within the accommodating space. The motor module 23 is fixed within the accommodating space and drives the impeller to rotate relative to the accommodating space. The inlet 211 of the modular component 2 is connected to the outlet 212 of the previous modular component 2. The inlet 211 of the first modular component 2 is connected to the liquid inlet 11 of the end cap 1. The outlet 212 of the last modular component 2 is connected to the liquid outlet 31 of the volute 3.

[0022] The usage process of this application is as follows: Select an appropriate number of modular components 2 according to the requirements, connect the modular components 2 end to end in sequence, connect the suction port 211 of the modular component 2 to the discharge port 212 of the previous modular component 2, connect the suction port 211 of the modular component 2 at the first end to the liquid inlet of the end cap 1, and connect the discharge port 212 of the modular component 2 at the end to the liquid outlet of the volute 3. After the assembly is completed, power on the motor module 23, and the motor module 23 drives the impeller 22 to rotate relative to the housing 21, centrifugally discharging the fluid and playing a pumping role.

[0023] Specifically, the end cap 1 is in the shape of a cap, and the end cap 1 matches the end of the housing 21. The end cap 1 has a liquid inlet 11, and the liquid inlet 11 is connected to the accommodating space of the modular component 2 located at the first end.

[0024] Specifically, the end cap 1 is detachably connected to the housing 21 of the modular component 2 located at the first end. In particular, the end cap 1 and the housing 21 are fixed by bolts.

[0025] Specifically, the housing 21 is cylindrical and has no caps at the top and bottom ends, and the impeller 22 is located inside the housing 21.

[0026] The end of the housing 21 is connected and sealed to the end of another housing 21, the end cap 1, or the volute 3. Specifically, the end of the housing 21 is provided with a housing sealing ring, which can seal the gaps between the housing 21 and the housing 21, between the housing 21 and the end cap 1, and between the housing 21 and the volute 3.

[0027] Specifically, the impeller 22 has an impeller inlet 221 located at the center of its axis and an impeller outlet 222 located circumferentially around its axis. The impeller 22 has an internal cavity that connects the impeller inlet 221 and the impeller outlet 221. In use, fluid enters the cavity of the impeller 22 through the impeller inlet 221 and exits through the impeller outlet 222.

[0028] Specifically, the motor module 23 includes a stator 231 and a permanent magnet 232. The stator 231 is fixed inside the housing 21, and the permanent magnet 232 is fixed on the impeller 22. When the motor module 23 is powered on, it drives the permanent magnet 232 and the impeller 22 to rotate inside the housing 21, thus performing work on the fluid.

[0029] Furthermore, the stator 231 includes an iron core 231a and a stator winding 231b. The iron core 231a is annular, and the stator winding 231b is disposed on the iron core 231a. To prevent the stator winding 231b from moving around the iron core 231a circumferentially, a pin hole 231c is provided on the iron core 231a, and a pin is provided in the pin hole 231c to limit the stator winding 231b and solve the problem of the stator winding 231b moving around the iron core 231a circumferentially.

[0030] Furthermore, the impeller 22 is provided with permanent magnets 232 on both ends of the impeller 22. Correspondingly, the motor module 23 includes two stators 231, which are respectively corresponding to the two ends of the impeller 22.

[0031] To address the issue of fixing the two stators 231, the modular assembly 2 further includes a front guide vane section 24 and a rear guide vane section 25. The front guide vane section 24 is located at the front end of the impeller 22 along the water flow direction and is fixed to the inner wall of the housing 21. The rear guide vane section 25 is located at the rear end of the impeller 22 along the water flow direction and is fixed to the inner wall of the housing 21. The two stators 231 are respectively fixed to the front guide vane section 24 and the rear guide vane section 25.

[0032] Specifically, the front guide vane section 24 has a liquid inlet in the middle, and the rear guide vane section 25 has a liquid outlet in the middle. The front guide vane section 24 and the rear guide vane section 25 are provided with closed annular grooves 26. The stator 231 is embedded in the annular grooves 26. The annular grooves 26 are covered with annular sealing caps 27, which play a role in sealing the stator 231.

[0033] The modular component 2 located at the head end, the leading vane section 24, and the end cover 1 are integrated into one unit.

[0034] The modular component 2 located at the end has its rear guide vane section 25 integrated with the volute 3.

[0035] In addition, the front guide vane section 24 and the rear guide vane section 25 also support the impeller 22. Rotary bearings 28 are provided at the liquid inlet of the front guide vane and the liquid outlet of the rear guide vane. Each rotary bearing 28 has a first rotating end and a second rotating end that can rotate relative to each other. The first rotating end is fixed to either the front guide vane section 24 or the rear guide vane section 25, and the second rotating end is fixed to the impeller 22. In this embodiment, the rotary bearing 28 is a radial thrust combined bearing.

[0036] It is understood that the first rotating end of the rotating bearing 28 of the modular component 2 located at the first end is fixed to the end cover 1, while the first rotating end of the rotating bearing 28 of the modular component 2 located at the end is fixed to the volute 3.

[0037] Specifically, the volute 3 includes a volute body 32 and a tail impeller 33. The drain port 31 is located circumferentially on the volute body 32 and tangentially along the end face of the volute body 32. The tail impeller 33 is rotatably disposed inside the volute body 32 and coaxially arranged with the volute body 32. After the liquid from the modular component 2 enters the volute body 32, it is finally discharged to the drain port 31 by the centrifugal force of the tail impeller 33.

[0038] The volute 3 also includes a tail impeller drive assembly 34, which is used to drive the tail impeller 33 to rotate relative to the volute body 32.

[0039] There are various ways to drive the tail impeller 33. In some feasible embodiments, the tail impeller drive assembly 34 includes a motor. The motor is located outside the volute body 32 and is connected to the shaft of the tail impeller 33, thereby driving the tail impeller 33 to rotate.

[0040] In this embodiment, the tail impeller drive assembly 34 includes a tail impeller stator 341 and a tail impeller permanent magnet 342. The tail impeller stator 341 is fixed inside the volute body 32, and the tail impeller permanent magnet 342 is fixed on the tail impeller 33. When the tail impeller stator 341 is energized, it drives the tail impeller permanent magnet 342 and the tail impeller 33 to rotate inside the volute body 32, thus performing work on the fluid.

[0041] Furthermore, considering the stability of stacking multiple modular components 2, the present invention also includes several fixing screws 4, which pass through the housing 21, and whose two ends are respectively bolted to the end cap 1 and the volute 3. The fixing screws 4 provide series fixation for the modular components 2, which helps to improve the stability of the stacking of the modular components 2.

[0042] The present invention also includes a temperature control module 5, which includes a temperature sensor 51, a flow and pressure sensor 52, a controller 53, and a power supply unit 54. The temperature sensor 51 is located at the stator 231 and the tail impeller stator 341 and is used to monitor the operating temperature of the stator 231 and the tail impeller stator 341 in real time. The flow and pressure sensor 52 is located at the suction port 211, the discharge port 212, the liquid inlet 11, and the liquid outlet 31 and is used to monitor the flow rate and pressure of the suction port 211, the discharge port 212, the liquid inlet 11, and the liquid outlet 31. The power supply unit 54 is used for electrical connection of the stator 231 and the tail impeller stator 341. The controller 53 is electrically connected to the temperature sensor 51, the flow and pressure sensor 52, and the power supply unit 54. The controller 53 adjusts the voltage of the power supply unit 54 based on the temperature detected by the temperature sensor 51 and the flow and pressure monitored by the flow and pressure sensor 52, thereby adjusting the rotational speed of the impeller 22. The adjustment method is shown in Figure 6: The controller 53 uses past experience to fit and generate a reference rotational speed and flow-head relationship curve for the impeller 22 and the tail impeller 33; during startup, the required flow-head is input to the controller 53. The controller 53 determines the rotational speed of the impeller 22 and the tail impeller 33 based on the aforementioned relationship curve, and precisely controls the total flow rate and head through the controller 53. Each temperature sensor detects the temperature at each of the stators 231 and the tail impeller stator 341. If a temperature sensor indicates that the temperature exceeds the limit temperature, the corresponding impeller 22 or tail impeller 33 is decelerated to prevent overheating damage. The rotational speed of its adjacent impeller 22 or tail impeller 33 is increased accordingly to maintain the equipment within the given temperature range and ensure that the total flow rate and head meet the requirements.

[0043] For ease of use, the actual working process of the present invention is now described with reference to the accompanying drawings: In use, the controller 53 controls the power supply unit 54 to energize the stator 231 and the tail impeller stator 341, generating a rotating magnetic field. This rotating magnetic field drives the permanent magnet 232 mounted on the impeller 22 and the tail impeller permanent magnet 342 mounted on the tail impeller 33, causing the impeller 22 to rotate. This rotates the impeller 22, performing work on the liquid drawn in by the housing 21, causing the liquid to rotate at high speed. The liquid flows towards the outer periphery of the impeller 22 and flows to the next stage modular component 2 through the rear guide vane section 25. If the modular component 2 is the penultimate stage, the liquid flows directly into the suction port of the tail impeller 33 after passing through the rear guide vane section 25, and is finally discharged from the pump through the radial discharge port 31. In addition, the high-speed flowing liquid inside can also cool the stator 231 and the tail impeller stator 341, and lubricate and cool the rotating bearing 28.

[0044] The beneficial effects of this invention are as follows: This invention provides a modular multistage centrifugal pump, including an end cover, multiple modular components, and a volute. The multiple modular components are connected end-to-end sequentially. The modular component at the first end is connected to the end cover, and the modular component at the last end is connected to the volute. Each modular component includes a housing, an impeller, and a motor module. A receiving space is formed within the housing. An inlet is axially formed along the receiving space, and an outlet is radially formed along the receiving space. The impeller is rotatably disposed within the receiving space. The motor module is fixed within the receiving space and drives the impeller to rotate relative to the receiving space. The motor module includes... The invention includes a stator and a permanent magnet. The stator is fixed inside the housing, and the permanent magnet is fixed on the impeller. The suction port of the modular component is connected to the discharge port of the preceding modular component. The suction port of the first modular component is connected to the liquid inlet of the end cover, and the discharge port of the last modular component is connected to the liquid outlet of the volute. This invention uses an axial flux motor as the drive motor for the centrifugal pump. Compared to existing solutions, this integration of the motor and centrifugal pump greatly reduces the axial space occupied by the pump body. This invention eliminates the easily damaged shaft seal device and coupling of traditional centrifugal pumps, improving the sealing performance of the centrifugal pump.

[0045] In the description of this application, it should be noted that the terms "upper" and "lower," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the module or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0046] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0047] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A modular multistage centrifugal pump, characterized in that, include: The system comprises an end cap, multiple modular components, with the first modular component connected to the end cap and the last modular component connected to the volute. Each modular component includes a housing, an impeller, and a motor module. The housing forms an accommodating space, and the housing has an intake port along the axial direction of the accommodating space and an outlet port along the radial direction of the accommodating space. The impeller is rotatably disposed within the accommodating space. The motor module includes a stator and a permanent magnet. The stator is fixed within the housing, and the permanent magnet is fixed to the impeller and the volute. The outlet port of the last modular component is connected to the drain port of the volute. The intake port of the modular component is connected to the outlet port of the previous modular component, and the intake port of the first modular component is connected to the inlet port of the end cap.

2. The modular multistage centrifugal pump as described in claim 1, characterized in that, An impeller inlet is provided at the center of the impeller axis, and an impeller outlet is provided circumferentially. The impeller has an internal cavity that connects the impeller inlet and the impeller outlet.

3. The modular multistage centrifugal pump as described in claim 1, characterized in that, The stator includes an iron core and a stator winding. The iron core is ring-shaped, and the stator winding is disposed on the iron core.

4. The modular multistage centrifugal pump as described in claim 3, characterized in that, The iron core has a pin hole, and a pin is provided in the pin hole to limit the stator winding from moving around in the circumferential direction.

5. The modular multistage centrifugal pump as described in claim 4, characterized in that, The permanent magnets are provided on both ends of the impeller, and the motor module includes two stators, which correspond to the two ends of the impeller respectively.

6. The modular multistage centrifugal pump as described in claim 5, characterized in that, The modular component further includes a front guide vane section and a rear guide vane section. The front guide vane section is located at the front end of the impeller along the water flow direction and is fixed to the inner wall of the housing. The rear guide vane section is located at the rear end of the impeller along the water flow direction and is fixed to the inner wall of the housing. The two stators are respectively fixed on the front guide vane section and the rear guide vane section.

7. The modular multistage centrifugal pump as described in claim 6, characterized in that, The front guide vane section has a liquid inlet in the middle, and the rear guide vane section has a liquid outlet in the middle. The front guide vane section and the rear guide vane section are provided with closed annular grooves. The stator is embedded in the annular grooves, and the annular grooves are provided with annular sealing caps.

8. The modular multistage centrifugal pump as described in claim 6, characterized in that, Rotary bearings are provided at the liquid inlet of the front guide vane and the liquid outlet of the rear guide vane. The rotary bearings have a first rotating end and a second rotating end that can rotate relative to each other. The first rotating end is fixed to the front guide vane section or the rear guide vane section, and the second rotating end is fixed to the impeller.

9. The modular multistage centrifugal pump as described in claim 8, characterized in that, The volute includes a volute body, a tail impeller, and a tail impeller drive assembly. The drain port is located circumferentially on the volute body and is arranged along the tangent direction of the end face of the volute body. The tail impeller is rotatably located inside the volute body and is coaxially arranged with the volute body. The tail impeller drive assembly is used to drive the tail impeller to rotate relative to the volute body.

10. The modular multistage centrifugal pump as described in claim 9, characterized in that, It also includes a temperature control module, comprising a temperature sensor, a flow and pressure sensor, a controller, and a power supply unit. The temperature sensor is located at the stator and the tail impeller drive assembly to monitor the operating temperature of the stator and the tail impeller drive assembly in real time. The flow and pressure sensor is located at the suction port, the discharge port, the liquid inlet, and the liquid outlet to monitor the flow rate and pressure at the suction port, the discharge port, the liquid inlet, and the liquid outlet. The power supply unit is used for electrical connection to the stator and the tail impeller drive assembly. The controller is electrically connected to the temperature sensor, the flow and pressure sensor, and the power supply unit. The controller controls the power supply unit based on the temperature detected by the temperature sensor and the flow rate and pressure monitored by the flow and pressure sensor.

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