Low-temperature immersed pump directly driven by radial integrated motor

Abstract

The invention discloses a low-temperature immersed pump directly driven by a radial integrated motor. The low-temperature immersed pump directly driven by the radial integrated motor comprises a fluid conveying module and the radial integrated motor. The fluid conveying module comprises an impeller drainage device and a pump shell assembly, the impeller drainage device comprises at least two stages of impellers which are sequentially arranged in the axial direction, and the impellers are located in an inner cavity of the pump shell assembly; the radial integrated motor is arranged around the impellers and is in transmission connection with the at least two stages of impellers. The motor and impeller integrated direct drive design is adopted, the axial length of the whole pump device is reduced, and therefore the overall structural size of the pump is reduced. And meanwhile, through cooperative use of the multiple stages of impellers, the pumping work efficiency is improved, the mechanical friction loss and the energy loss are reduced, and therefore the power density is improved. The structure is simplified, and the overall operation reliability and stability of the pump can be improved. And the motor directly drives the impeller, so that the vibration and noise level in the operation process of the pump can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of submersible pumps, and in particular to a low-temperature submersible pump directly driven by a radially integrated motor. Background Art

[0002] With the accelerated adjustment of the global energy structure, the proportion of clean energy in the energy system is increasing. Liquefied natural gas (LNG), as a clean, efficient and abundant energy source, plays an increasingly critical role in energy supply. In the entire LNG industry chain, from production and storage to transportation and terminal applications, cryogenic submersible pumps are core transportation equipment. Their performance is directly related to the operating efficiency, cost control, safety and stability of the entire industry chain. Therefore, the innovative design of LNG cryogenic submersible pumps has become an inevitable trend.

[0003] Traditional cryogenic submersible pumps work by using an electric motor to drive an impeller, and the two are connected and power is transmitted through a drive shaft. The impeller is located inside the pump body and the motor is arranged outside the pump body. The Chinese patent application number 201922199346.X discloses a new type of cryogenic submersible pump, in which the outer casings of the pump part and the motor part are both set as a split assembly structure, which is convenient for installation and maintenance, and adjustment of the internal structure, which improves this structural arrangement to a certain extent. However, the structural size of this cryogenic submersible pump is large, resulting in a decrease in the power density of the entire system. At the same time, due to the presence of transmission parts, the pump will cause energy loss during operation. In addition, the motor is located outside the pump body, so it is necessary to consider the cooling problem of the motor, which increases the operating cost of the cryogenic submersible pump.

[0004] In summary, existing cryogenic submersible pumps have technical problems of low power density and large energy loss. Summary of the Invention

[0005] The purpose of this application is to overcome the above-mentioned technical deficiencies and propose a low-temperature submersible pump directly driven by a radial integrated motor to solve the technical problems of low power density and large energy loss in the existing technology.

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions: The present application provides a low-temperature submersible pump directly driven by a radially integrated motor, comprising a fluid delivery module and a radially integrated motor.

[0007] A fluid delivery module, comprising an impeller drainage device and a pump casing assembly, wherein the impeller drainage device comprises at least two stages of impellers arranged in sequence along the axial direction, and the impellers are located in the inner cavity of the pump casing assembly; The radial integrated motor is arranged around the impeller and is respectively connected to at least two stages of the impeller in driving connection.

[0008] In some embodiments of the present application, the impeller drainage device further includes guide vanes and a fairing. The guide vanes are arranged on the circumferential outer side of the impeller. The fairing is located between two adjacent stages of the impellers. The collecting port of the fairing faces the outlet of one of the impellers, and the guiding port of the fairing faces the inlet of the other impeller.

[0009] In some embodiments of the present application, the impeller drainage device further includes a seal and a plurality of telescopic protrusions. The seal includes a plurality of comb-shaped sealing teeth. The seal is arranged between the impeller and the guide vane. The telescopic protrusions are located on the outer circumference of the guide vane. The fairing has a plurality of side holes, and the telescopic protrusions pass through the side holes.

[0010] In some embodiments of the present application, the pump housing assembly is provided with a liquid suction port, a liquid discharge port, a gas suction port, and a gas discharge port. The liquid suction port and the gas suction port are arranged at the first end of the pump housing assembly. The gas discharge port is arranged at the second end of the pump housing assembly. The first end and the second end are oppositely arranged. The liquid discharge port is arranged in the tangential direction of the pump housing assembly.

[0011] In some embodiments of the present application, the fluid delivery module further includes an inducer and a steam tracing device. The inducer is arranged inside the liquid suction port, and the steam tracing device is arranged inside the gas discharge port.

[0012] In some embodiments of the present application, the radially integrated motor includes at least two rotors, a stator, and roller bearings. At least two of the rotors are arranged in sequence along the axial direction and are coaxially arranged with the fairing. The stator is sleeved on the radial outer side of at least two of the rotors. The roller bearings are arranged between the rotors and the stator.

[0013] In some embodiments of the present application, a shrink fit sleeve is further included. Each rotor is connected to an impeller by interference fit through the shrink fit sleeve.

[0014] In some embodiments of the present application, the blade profile of the impeller is cylindrical, and the guide vanes are spirally distributed.

[0015] In some embodiments of the present application, the surface of the impeller blades is coated with a polytetrafluoroethylene coating. The guide vanes and the pump housing assembly include nickel alloy. The rotors include neodymium iron boron permanent magnets. The stator includes polyesterimide electromagnetic copper wire and polytetrafluoroethylene insulating material. The roller bearings include high nitrogen stainless steel. The radially integrated motor includes polytetrafluoroethylene encapsulation material.

[0016] In some embodiments of the present application, a control module is further included, which includes a controller, a monitoring sensor, and a human-computer interaction device. The controller is respectively connected to the monitoring sensor, the human-computer interaction device, and the radial integrated motor signal.

[0017] Compared with the existing technology, the technical solution provided by this application brings the following beneficial technical effects: This application utilizes an integrated direct-drive design with a motor and impeller, eliminating traditional intermediate transmission components and reducing the axial length of the entire pump unit, thereby reducing the overall pump size. This reduction in transmission links, combined with the use of a multi-stage impeller, improves pumping efficiency, reduces mechanical friction and energy losses, and thus increases power density. This simplified structure helps improve the overall operational reliability and stability of the pump. The motor directly drives the impeller, helping to reduce vibration and noise levels during pump operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in this application, the following briefly introduces the drawings required for use in the embodiments: Figure 1 This is a schematic structural diagram of a low-temperature submersible pump directly driven by a radially integrated motor in an embodiment of the present application; Figure 2 1 is a cross-sectional schematic diagram of a low-temperature submersible pump directly driven by a radially integrated motor in an embodiment of the present application; Figure 3 This is a schematic diagram of the appearance of another cryogenic submersible pump directly driven by a radially integrated motor in an embodiment of the present application; Figure 4 yes Figure 1 Schematic diagram of the structure of the center guide vane; Figure 5 yes Figure 1 Schematic diagram of the structure of the rotor and roller bearing; Figure 6 yes Figure 3 Schematic diagram of the structure of the middle volute; Figure 7 This is a partial schematic diagram of a guide vane in an embodiment of the present application; Figure 8 This is a schematic diagram of a method for controlling a low-temperature submersible pump directly driven by a radially integrated motor in an embodiment of the present application.

[0019] Reference numerals: Fluid delivery module 1, impeller drainage device 11, first-stage impeller 111, second-stage impeller 112, guide vanes 113, guide cover 114, pump casing assembly 12, pump casing front cover 121, pump casing middle section 122, volute 123, flange 124, liquid suction port 12a, liquid discharge port 12b, air intake port 12c, air discharge port 12d, inducer 13; Radially integrated motor 2, first rotor 21, second rotor 22, stator 23, roller bearing 24. Specific embodiments

[0020] In order to make the objectives, technical solutions and advantages of this application clearer, the following further elaborates on this application in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this application and are not used to limit this application.

[0021] Those skilled in the art of this technology can understand that in this specification, the term "including" is an open-ended expression, meaning that there are the described features but other features are not excluded. The orientation terms "upper", "lower", "left", "right", etc. are exemplary directions based on the accompanying drawings. Features defined with "first" and "second" implicitly include one or more of such features. The singular form can also be used for the plural form. "Multiple" means two or more. The terms "installed", "connected", and "joined" can be fixedly connected, detachably connected, or integrally connected; they can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two components. In addition, "connection" can include wireless connection.

[0022] The objective of this application is to overcome the above technical deficiencies and propose a cryogenic submersible pump directly driven by a radially integrated motor 2, to solve the technical problems of low power density and large energy loss in the prior art.

[0023] To achieve the above technical objectives, this application adopts the following technical solutions: As Figures 1 to 7 shown. This application provides a cryogenic submersible pump directly driven by a radially integrated motor 2, including a fluid delivery module 1 and a radially integrated motor 2.

[0024] The fluid delivery module 1 includes an impeller drainage device 11 and a pump housing assembly 12. The impeller drainage device 11 includes at least two stages of impellers arranged in sequence along the axial direction, and the impellers are located in the inner cavity of the pump housing assembly 12; the impeller drainage device 11 includes at least two impellers. When each impeller rotates, its blades generate a force on the flowing cryogenic liquid, throwing the liquid from the center to the edge, thereby creating a low-pressure area in the center of the impeller to suck in the liquid, and at the same time creating a high-pressure area at the edge of the impeller to press out the liquid. The design of multiple stages of impellers enables the liquid to pass through multiple impellers in sequence, and each impeller boosts the pressure of the liquid once. The pump housing assembly 12 is a fixed component that houses the impellers and guides the fluid flow. It forms a flow channel that guides the liquid to enter the first-stage impeller 111 from the pump inlet, then flow through the subsequent stages of impellers in sequence, and finally discharge from the pump outlet. The shape design of the pump housing can reduce fluid impact, reduce energy loss, and improve pump efficiency.

[0025] The radial integrated motor 2 is arranged around the impeller and is respectively drivingly connected to at least two stages of the impeller. Different from a traditional pump where the motor is placed at one end of the pump, the motor is radially integrated into the pump structure and surrounds the periphery of the impeller. The motor directly drives the impeller to rotate. Since the motor is radially arranged, its rotor can be directly connected to each stage of the impeller to drive the impeller.

[0026] By adopting the integrated direct drive design of the motor and the impeller, this application eliminates the traditional intermediate transmission components, reduces the axial length of the entire pump device, thereby reducing the overall structural size of the pump. The number of transmission links is reduced. At the same time, by using multiple stages of impellers in cooperation, the pumping efficiency is improved, the mechanical friction loss and energy loss are reduced, and thus the power density is increased. The simplified structure helps to improve the overall operation reliability and stability of the pump. The direct drive of the motor to the impeller helps to reduce the vibration and noise levels during the operation of the pump.

[0027] In some embodiments of this application, the impeller flow guiding device 11 further includes a guide vane 113 and a flow guiding cover 114. The guide vane 113 is arranged on the circumferential outer side of the impeller. The flow guiding cover 114 is located between two adjacent stages of the impeller. The flow collecting port of the flow guiding cover 114 faces the outlet of one of the impellers, and the flow guiding port of the flow guiding cover 114 faces the inlet of the other impeller.

[0028] The cryogenic liquid first enters the first-stage impeller 111 and is accelerated and pressurized. Then, the guide vane 113 is arranged on the outer circle in the circumferential direction of the impeller. The high-speed liquid flows through the guide vane 113 on the outer side of the impeller, converting the velocity energy into pressure energy. Next, the liquid passes through the flow guiding cover 114 located between two stages of the impellers and is precisely guided to the inlet of the next-stage impeller 111. Repeating this process, through the synergistic effect of multiple stages of impellers and the flow guiding structure, the liquid pressure is gradually increased to the required value. The motor directly drives the impeller to rotate to complete the whole process.

[0029] The pressure increasing effect of the guide vane 113 can more effectively convert the high-speed kinetic energy at the outlet of the impeller into pressure energy, reduce the energy loss inside the fluid, and improve the efficiency of a single-stage impeller.

[0030] The stable transportation of the flow guiding cover 114 avoids the direct and disorderly collision and mixing of the liquid between stages, reduces the flow loss and impact loss, and ensures that the liquid enters the next-stage impeller 111 in a more favorable state.

[0031] In some embodiments of this application, the impeller flow guiding device 11 includes a seal and a plurality of telescopic protrusions. The seal includes a plurality of comb-shaped seal teeth. The seal is arranged between the impeller and the guide vane 113; The telescopic protrusion is located on the outer periphery of the guide vane 113 , and the guide cover 114 has a plurality of side holes, through which the telescopic protrusion passes.

[0032] Comb-like sealing teeth form a labyrinth seal between the impeller's outer ring and the inner ring of the guide vanes 113, preventing liquid leakage. The shroud 114 is bolted to the inner wall of the stator 23. The telescopic, thin, plate-like protrusions on the guide vanes 113 extend through side holes around the circumference of the shroud 114, securing it.

[0033] The labyrinth seal effectively prevents cryogenic liquid leakage, minimizing losses and ensuring efficiency and safety. Double fixing with protrusions and bolts ensures precise alignment of the shroud 114, providing a stable structure and strong vibration resistance. This design adapts to low-temperature environments, reduces leakage risks, and improves long-term operational reliability.

[0034] In some embodiments of the present application, the pump housing assembly 12 is provided with a liquid suction port 12a, a liquid discharge port 12b, an air suction port 12c, and an air exhaust port 12d. The liquid suction port 12a and the air suction port 12c are arranged at the first end of the pump housing assembly 12, and the air exhaust port 12d is arranged at the second end of the pump housing assembly 12. The first end and the second end are arranged opposite to each other, and the liquid discharge port 12b is arranged in the tangential direction of the pump housing assembly 12.

[0035] The main function of the pump casing is to correctly inhale and discharge fluid, inhale gas for pre-cooling before operation, and discharge excess gas during operation to ensure the internal air pressure balance of the low-temperature submersible pump during operation. The fluid first enters through the suction port 12a. After being pressurized by the impeller, part of the liquid is collected in the guide cover 114 and directed to the exhaust port 12d to process the gas therein. Most of the liquid flows along the inner wall of the pump casing and is finally discharged through the tangential discharge port 12b. This tangential discharge design adopts the principle of the volute 123 pump and uses centrifugal force to make the liquid form a rotating flow in the pump casing, which is conducive to energy conversion and pressure stability.

[0036] The tangential discharge port 12b effectively collects and guides the high-speed liquid ejected by the impeller, decelerating it within the pump casing and converting some of its kinetic energy into pressure energy. This ensures a more stable energy state and minimizes pressure fluctuations during fluid output. The placement of the intake port 12c and exhaust port 12d at opposite ends, combined with guidance from the flow guide 114 (with the collecting end facing the intake port 12c and the guiding end facing the exhaust port 12d), facilitates centralized gas processing in a specific area within the pump. This may include built-in gas-liquid separation or compression functions, improving processing efficiency.

[0037] In some embodiments of the present application, the fluid delivery module 1 further includes an inducer 13 and a steam heating device, wherein the inducer 13 is disposed inside the liquid suction port 12a, and the steam heating device is disposed inside the exhaust port 12d.

[0038] When cryogenic liquid enters the liquid suction port 12a, it first flows through the inducer 13. The inducer 13 pre - works on the liquid by rotating, generating an initial low - pressure area and a certain pre - swirl velocity, which helps to preliminarily pressurize the liquid, ensure that the liquid can be more smoothly and stably sucked into the pump, and reduce flow disturbances.

[0039] The function of the steam tracing device is to heat the cryogenic gas (or gas - liquid mixture) discharged from the pump using the heat of steam. This can prevent the cryogenic gas from being over - cooled, condensed or forming solids in the discharge pipeline. Prevent the pipeline from shrinking, freezing or being damaged due to low temperature.

[0040] The addition of the inducer 13 significantly improves the performance of the pump at the suction end, can effectively prevent the occurrence of cavitation, reduce fluid impact and eddy currents, thus achieving more accurate and stable fluid suction. The steam tracing device effectively solves the freezing and blockage problems that may occur after the cryogenic gas is discharged, and extends the equipment life.

[0041] The pump housing assembly 12 is composed of multiple parts such as the front cover plate 121 of the pump housing, the middle section 122 of the pump housing, the volute 123 and the flange 124. These components are not integrally cast, but are assembled together by bolt connection. The front cover plate 121 of the pump housing (including the liquid suction port and the air suction port 12c) is bolt - connected to the middle section 122 of the pump housing (including the cavity for installing the impeller and part of the flow path); the volute 123 (responsible for collecting the liquid thrown out by the impeller and converting energy, including the liquid discharge port 12b) is also bolt - connected to the middle section 122 of the pump housing. The flange 124 is provided at the liquid suction port 12a and the liquid discharge port 12b for connecting to other pipelines or equipment.

[0042] In some embodiments of the present application, the radial integrated motor 2 includes at least two rotors, a stator 23, and roller bearings 24. At least two of the rotors are arranged axially in sequence and are coaxially arranged with the guide cover 114. The stator 23 is sleeved on the radial outer side of at least two of the rotors, and the roller bearings 24 are arranged between the rotors and the stator 23.

[0043] The radial integrated motor 2 adopts a multi - rotor structure. The stator 23 is annularly sleeved on the radial outer side of all the rotors, surrounding them. The roller bearings 24 are conically arranged between the rotors and the stator 23, used to support the rotors and allow them to rotate.

[0044] The fairing 114 not only guides the fluid but also undertakes the function of axial positioning. The two rotors are axially positioned through the fairing 114, that is, they are clamped between the fairing 114 and the stator 23. The front end face of the first rotor 21 is aligned with the front end face of the stator 23, and the rear end face of the second rotor 22 is aligned with the rear end face of the stator 23. This tight fit further ensures the accuracy and stability of the rotors in the axial position.

[0045] When the windings on the stator 23 are energized to generate a rotating magnetic field, this magnetic field acts on the two coaxially arranged rotors simultaneously, causing them to rotate synchronously. The tapered roller bearing 24 not only bears the radial load of the rotors but also can effectively withstand the thrust from the axial direction, preventing axial movement.

[0046] The stator 23 adopts a double-layer overlapping winding. The coils are wound in a certain order in sequence, the upper and lower coils are stacked in layers, and the coils of each layer are connected in sequence according to a specific pitch to achieve efficient electromagnetic conversion. The winding lead terminals are arranged in the junction box. Thereby improving the efficiency of the conversion of electrical energy into mechanical energy and facilitating the access and control of external power supplies.

[0047] A sealing ring is provided between the front end face of the fairing 114 and the rear end face of the first rotor 21. The sealing ring prevents the fluid from leaking between the fairing 114 and the first rotor 21. The axial dimension of the large diameter of the fairing 114 is equal to the axial gap between the rear end face of the first rotor 21 and the front end face of the second rotor 22. Ensure the accurate axial positioning of the fairing 114 and ensure that the fluid accurately flows from the primary impeller 111 to the secondary impeller 112.

[0048] In some embodiments of the present application, it further includes a shrink disc. Each of the rotors is connected to one of the impellers in an interference fit through the shrink disc.

[0049] By using the shrink disc and the interference fit, the impeller is fixed on the rotor to form an integral body. The motor directly drives this integral body to rotate, and the impeller rotates accordingly, thereby efficiently transferring energy to the fluid to achieve transportation. This direct-drive integrated design simplifies the structure and reduces the energy transfer link.

[0050] In some embodiments of the present application, the blade profile of the impeller is cylindrical, and the guide vanes 113 are spirally distributed.

[0051] The low-temperature submersible pump of the present application adopts a cylindrical blade impeller and a flow channel guide vane 113 with a spiral structure that are arranged in coordination with each other. The cylindrical blade impeller can make the fluid more evenly distributed at the impeller inlet, effectively reduce the inlet flow velocity, reduce the disturbance and pressure fluctuation of the fluid, thereby improving the anti-cavitation performance of the impeller, avoiding or reducing the occurrence of cavitation, extending the service life of the impeller, and ensuring the stable operation of the pump. The spiral flow channel guide vane 113 can make the water flow smoother, reduce the degree of turbulence, reduce the vibration and noise of the pump operation, and improve stability and reliability. A labyrinth sealing structure composed of comb-shaped sealing teeth arranged at the mating surface and designed in depth, width and number is adopted between the impeller and the guide vane 113. Among them, the blades of the cylindrical blade impeller are evenly distributed along the circumferential direction and have a streamlined shape that is suitable for the transportation of low-temperature fluids. The friction is small, which is conducive to the transportation of fluids.

[0052] In some embodiments of the present application, the blade surface of the impeller is coated with a polytetrafluoroethylene coating, the guide vane 113 and the pump casing assembly 12 include a nickel alloy, the rotor includes a neodymium iron boron permanent magnet, the stator 23 includes polyesterimide electromagnetic copper wire and polytetrafluoroethylene insulation material, the roller bearing 24 includes high nitrogen stainless steel, and the radial integrated motor 2 includes polytetrafluoroethylene packaging material.

[0053] When a cryogenic submersible pump is transporting fluids, the impeller needs to frequently cope with the continuous impact of the cryogenic medium and will also be subjected to greater stress caused by the impact. Therefore, austenitic stainless steel 1Cr18Ni9T with a face-centered cubic crystal structure is used. This material has excellent impact toughness and strength in low-temperature environments, which can ensure the structural stability of the submersible pump during operation and maintain the efficient and stable working state of the cryogenic submersible pump. Secondly, the fluid transported by the submersible pump, such as LNG, contains impurities such as sulfides and carbon dioxide, which may cause corrosion problems. The dense chromium oxide protective film formed on the surface of austenitic stainless steel 1Cr18Ni9T in a low-temperature environment can effectively resist the erosion of corrosive media and extend the service life of the impeller. Furthermore, the impeller surface is covered with a polytetrafluoroethylene coating, which can form a uniform micro-granular surface, thereby reducing friction to prevent impurities in LNG from adhering.

[0054] The cryogenic submersible pump is a multi-stage pump. The guide vane 113 serves as the energy transfer channel between stages and will be continuously subjected to the huge centrifugal force and fluid impact force caused by the cryogenic medium. Therefore, the nickel alloy Inconel 625 is used. It can stably bear these complex stresses, ensure the efficient operation of the components at low temperatures, maintain the rated flow and head of the cryogenic submersible pump, and achieve long-term stable operation.

[0055] The cryogenic submersible pump's air inlet and seals are made of polytetrafluoroethylene (PTFE). This material maintains excellent flexibility even at low temperatures. When the internal pressure of the pump changes, the PTFE seals adapt to the pressure and conform tightly to the sealing surface, achieving a self-sealing effect and ensuring operational safety. A steam heating cable is installed at exhaust port 12d to prevent the discharged fluid from solidifying or freezing.

[0056] Cryogenic submersible pumps operate in cryogenic, sealed conditions, and their pump casings are constructed from a nickel alloy (Monel). This material exhibits high strength and toughness at low temperatures, capable of withstanding the complex stresses generated by internal pump pressure and fluid flow, as well as mechanical vibrations in cryogenic environments. Furthermore, Monel's low shrinkage at low temperatures prevents excessive gaps in the pump casing connections due to shrinkage, thus preventing fluid leakage. Submersible pumps operate in low-temperature, high-pressure environments with corrosive media, requiring their casings to exhibit excellent corrosion resistance. Monel's ability to remain crack-free in stress corrosion environments significantly improves the pump's reliability in harsh operating conditions and extends its service life.

[0057] The radial integrated motor 2 requires excellent electromagnetic properties at low temperatures. Therefore, the core components of the first and second rotors 21 and 22 utilize neodymium iron boron (NdFeB) permanent magnets. The high remanence and coercive force stability of these magnets at low temperatures enable them to generate a stronger and more stable magnetic field. Within the sealed, low-temperature motor environment, this stable magnetic field ensures efficient motor operation, providing continuous and stable power output to the pump, and ensuring stable flow and head for the submersible pump under low-temperature conditions. The stator 23 winding utilizes multi-strand Q (ZY / XY)-3 / 220) thick-film polyesterimide electromagnetic copper wire and polytetrafluoroethylene insulation. These materials offer strong corrosion resistance and excellent insulation properties, ensuring proper operation of the motor stator 23 in sealed, low-temperature environments containing low levels of corrosive media. The motor's tapered roller bearings 24 utilize high-nitrogen stainless steel, Cronidur 30 (X30CrMoN15-2). This material maintains excellent impact toughness even at low temperatures, effectively preventing structural fracture due to low-temperature embrittlement and ensuring long-term, reliable operation of the tapered roller bearings 24.

[0058] In some embodiments of the present application, a control module is further included, which includes a controller, a monitoring sensor, and a human-computer interaction device. The controller is signal-connected to the monitoring sensor, the human-computer interaction device, and the radial integrated motor 2 respectively.

[0059] The fluid conveying module 1 and the radial integrated motor 2 are arranged crosswise inside the submersible pump. The radial integrated motor 2 drives the fluid conveying module 1 to convey the fluid entering the submersible pump. The intelligent control module is integrated into the control box, which is arranged on the middle section 122 of the pump casing and fixed to the outer wall by bolts.

[0060] The controller of the above-mentioned cryogenic submersible pump adopts a programmable logic controller (PLC) as the main control core, performs logical operations and command output control on the entire control module, and is matched with an ACS510 series frequency converter as a drive unit. The frequency converter achieves precise adjustment of the speed of the radial integrated motor 2 of the LNG cryogenic submersible pump by changing the power supply frequency, thereby controlling the flow and pressure of the pump; the control module is also equipped with a power supply module to provide stable power for the system, and monitors the operating status parameters of the submersible pump in real time through various monitoring sensors such as temperature, pressure, flow, and liquid level, and feeds back to the PLC, which processes it according to preset logic. At the same time, it has a display and operation module for the human-computer interaction device to display operating parameters and receive instructions. The communication module supports data interaction with external devices, as well as various protection circuits such as overcurrent, overheating, undervoltage, and overvoltage to protect the submersible pump and control module, ensuring stable and safe operation of the system.

[0061] First, the first rotor 21 and the first-stage impeller 111 are connected as one by means of an interference fit and an expansion sleeve, and the second rotor 22 and the second-stage impeller 112 are also connected as one by means of an interference fit and an expansion sleeve. The first rotor 21 and the first-stage impeller 111 combination is assembled to the axial front end of the stator 23 through the tapered roller bearing 24. The front end face of the first rotor 21 coincides with the front end face of the stator 23, thereby achieving axial positioning of the combination.

[0062] Next, place the guide vane 113 at the large-diameter end of the air guide cover 114. The annular guide vane 113 and the rotating air guide cover 114 remain coaxial, but at this time the retractable thin plate-shaped protrusion does not pass through the hole on the wall of the air guide cover 114. Place the whole thing into the stator 23, determine the position, and let the retractable thin plate-shaped protrusion pass through the hole on the wall of the air guide cover 114. Then use bolts to fix the air guide cover 114 to the inner wall of the stator 23 for the second time.

[0063] Subsequently, the second rotor 22 and second-stage impeller 112 assembly is assembled to the end of the stator 23 via tapered roller bearings 24. The rear end face of the second rotor 22 coincides with the rear end face of the stator 23. At this point, the axial dimension of the major diameter of the shroud 114 is equal to the axial clearance between the rear end face of the first rotor 21 and the front end face of the second rotor 22. The guide vanes 113 are secured to the circumferential position of the second-stage impeller 112 by retractable thin plate-like protrusions. After installation, the stator-rotor gap of the radially integrated motor 2 is encapsulated with a diaphragm sheet.

[0064] Subsequently, place the assembled whole in the middle section 122 of the pump casing. After determining the axial position, connect the rear end of the stator 23 to the volute 123 and the front end to the front cover plate 121 of the pump casing, both using bolt connection methods. Fix the inducer 13 in the liquid suction port 12a of the front cover plate 121 of the pump casing through threaded connection, and then fix the control box on the middle section 122 of the pump casing of the submersible pump, thus completing the assembly and fixation of the entire cryogenic submersible pump. The above structure design is simple, highly reliable, and the assembly process is simple and convenient to operate.

[0065] This application also provides a regulation method, which uses the cryogenic submersible pump directly driven by the radial integrated motor 2 in the above embodiment, as Figure 8 shown.

[0066] Compared with the prior art, the beneficial technical effects brought by the technical solution provided in this application include: For this cryogenic submersible pump, the integrated design of the motor rotor and the pump impeller is adopted to reduce the overall structural size of the pump and improve the power density. By using multiple impellers in cooperation, the pumping efficiency is significantly improved. The tapered roller bearing 24 is adopted to effectively solve the problems of axial force and radial force. The pump is equipped with a control box, integrating multiple sensors to realize motor and temperature detection, featuring automation and intelligence. The middle section 122 of the pump casing is provided with a fin structure, which cooperates with the fiberglass insulation layer to improve the insulation performance. The flow guide cover 114 at the end of the first-stage impeller 111 realizes directional and efficient pumping transportation.

[0067] Those skilled in the art of this technology can understand that the various operations, methods, steps, measures, and solutions in the processes discussed in this application can be alternated, changed, rearranged, decomposed, combined, or deleted.

[0068] The specific implementation manners of the present application described above do not constitute a limitation on the protection scope of the present application. Any other corresponding changes and deformations made according to the technical concept of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A cryogenic submersible pump with direct drive by a radially integrated motor, characterized in that, include: A fluid delivery module, comprising an impeller drainage device and a pump casing assembly, wherein the impeller drainage device comprises at least two stages of impellers arranged in sequence along the axial direction, and the impellers are located in the inner cavity of the pump casing assembly; The radial integrated motor is arranged around the impeller and is respectively connected to at least two stages of the impeller in driving connection.

2. The cryogenic submersible pump with direct drive of a radially integrated motor according to claim 1, characterized in that, The impeller drainage device also includes guide vanes and a guide cover. The guide vanes are arranged on the circumferential outer side of the impeller. The guide cover is located between two adjacent stages of the impellers. The collecting port of the guide cover faces the outlet of one of the impellers and the guide port of the guide cover faces the inlet of the other impeller.

3. The low-temperature submersible pump directly driven by a radially integrated motor according to claim 2, characterized in that: The impeller drainage device also includes a seal and a plurality of telescopic protrusions. The seal includes a plurality of comb-shaped sealing teeth. The seal is arranged between the impeller and the guide vane. The telescopic protrusion is located on the outer periphery of the guide vane. The guide cover has a plurality of side holes, and the telescopic protrusion passes through the side holes.

4. The cryogenic submersible pump with direct drive of a radially integrated motor according to claim 2, characterized in that The pump housing assembly is provided with a liquid suction port, a liquid discharge port, an air intake port, and an air exhaust port. The liquid suction port and the air intake port are arranged at the first end of the pump housing assembly, and the air exhaust port is arranged at the second end of the pump housing assembly. The first end and the second end are arranged opposite to each other, and the liquid discharge port is arranged in the tangential direction of the pump housing assembly.

5. The cryogenic submersible pump with direct drive of a radially integrated motor according to claim 4, characterized in that The fluid delivery module further includes an inducer, which is arranged inside the liquid suction port.

6. The cryogenic submersible pump with direct drive of a radially integrated motor according to claim 2, characterized in that The radial integrated motor includes at least two rotors, a stator, and a roller bearing. The at least two rotors are arranged in sequence along the axial direction and are coaxially arranged with the air guide cover. The stator is sleeved on the radial outside of the at least two rotors, and the roller bearing is arranged between the rotor and the stator.

7. The cryogenic submersible pump with direct drive by a radially integrated motor according to claim 6, wherein It also includes a tightening sleeve, and each of the rotors is connected to one of the impellers through an interference fit via the tightening sleeve.

8. The cryogenic submersible pump with direct drive of a radially integrated motor according to claim 6, characterized in that, The blades of the impeller are cylindrical in profile, and the guide vanes are distributed in a spiral shape.

9. The cryogenic submersible pump with direct drive of a radially integrated motor according to claim 6, characterized in that, The blade surface of the impeller is coated with a polytetrafluoroethylene coating, the guide vanes and the pump casing assembly include nickel alloy, the rotor includes neodymium iron boron permanent magnets, the stator includes polyesterimide electromagnetic copper wire and polytetrafluoroethylene insulation material, the roller bearing includes high nitrogen stainless steel, and the radial integrated motor includes polytetrafluoroethylene packaging material.

10. The cryogenic submersible pump with direct drive of a radially integrated motor according to claim 1, characterized in that, It also includes a control module, which includes a controller, a monitoring sensor, and a human-computer interaction device. The controller is respectively connected to the monitoring sensor, the human-computer interaction device, and the radial integrated motor signal.

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