CN205225768U - Marine immersed pump of vertical low temperature - Google Patents

Abstract

The utility model relates to a pump, special equipment design vertical cryogenic pump. A marine immersed pump of vertical low temperature is proposed, including liquid motor and the immersed pump of diving, the liquid motor of diving includes motor shaft, motor generator room and motor casing, is equipped with the bearing on the motor shaft, and the immersed pump is including setting up impeller, impeller apron and the axial force balancing unit in flow passage components, and latent liquid motor is with the integrative encapsulation of immersed pump and install the pump tower lower extreme in the cabin, axial force balancing unit is located between latent liquid motor and the impeller, the impeller and the liquid motor coaxial of diving, the exit end of impeller passes through clearance and motor generator room intercommunication on the axial force balancing unit, and the entry end that is provided with balanced loop and balanced loop in the motor generator room is located the motor generator room. The utility model provides an among the prior art pump and motor bring the problem to neutrality through the coupling joint to do not need extra motor to the pump to provide the heat dissipation, the cooling effect is better, saves space and the cost.

Description

Vertical cryogenic marine submersible pump

technical field

The utility model relates to a marine pump, especially a vertical cryogenic pump.

Background technique

At present, low-temperature pumps are required to transport low-temperature medium in LNG (liquefied natural gas) carriers. Since the medium is low-temperature, flammable, explosive, and easy to vaporize, the pump equipment for transporting such medium is required to have reliable sealing, The operating liquid loss is small and the structure is safe and stable and reliable. This type of pump is difficult to design, manufacture and test. Therefore, at present, most of this kind of vertical cryogenic marine submersible pumps in China rely on imports, and there are problems such as high product prices and insufficient technical support. The localization of vertical cryogenic submersible pump equipment is conducive to the cost control of LNG transportation, the application expansion of vertical cryogenic marine submersible pumps in propane, ethylene and other projects, and the design and manufacture of domestic large-scale cryogenic submersible pumps Level up.

In the prior art, the liquid in the low-temperature cabin is usually connected with the impeller at the pump tower by an external ordinary motor, and the power is provided by the motor outside the cabin. Since the conveying medium is flammable and explosive, there are explosion-proof requirements for the motor. At the same time, Since the connection between the motor and the pump outside the cabin needs to be realized through an intermediate coupling, it will bring certain alignment problems. Ordinary vertical pumps, in order to prevent the medium in the pump from leaking out, need to use dynamic seals to seal the shaft, which cannot achieve zero leakage, and there is a danger caused by seal leakage. Vertical pumps with external motors need external cooling water or fans to cool them, and auxiliary cooling water or electric equipment need to be added, making the overall equipment bulky, and its bearings need to be lubricated by adding grease or lubricating oil frequently.

Utility model content

In order to solve the above problems, the utility model provides a vertical low-temperature marine submersible pump, which solves the problem of neutralization caused by the connection between the pump and the motor through a coupling in the prior art, and does not require additional support for the motor of the pump. Heat dissipation, better cooling effect, saving space and cost.

In order to achieve the above object, the technical scheme adopted by the utility model is as follows: a vertical low-temperature marine submersible pump is proposed, including a submersible motor and a submersible pump, and the submersible motor includes a motor shaft, a motor room and a motor housing, and Equipped with bearings, the submersible pump includes an impeller, an impeller cover plate and an axial force balance device arranged in the flow-passing part. The submersible motor and the submersible pump are integrally packaged and installed at the lower end of the pump tower in the cabin. The force balance device is located between the submersible motor and the impeller; the impeller is coaxial with the submersible motor, and the outlet end of the impeller communicates with the motor room through the gap on the axial force balance device. The inlet port is located in the motor compartment.

The axial force balance device includes a balance drum and a balance disc. The balance drum is located at the junction of the impeller cover plate and the flow-passing component and is fixed on the impeller cover plate. There is a gap between the balance drum and the flow-passing component; the balance disc is located at the Between the cover plate and the motor housing, the balance disc is fixed on the motor housing, and there is a gap communicating with the motor chamber between the balance disc and the motor housing.

The coolant of the submersible motor is the pumping medium, the inlet of the coolant is located in the motor chamber, and the outlet passes through the low-temperature cable junction box or the inside of the motor shaft to communicate with the cabin, and the motor shaft is a hollow shaft.

The return pipeline of the balance circuit is arranged outside the motor casing or inside the submersible motor casing, or inside the motor shaft, and the motor shaft is a hollow shaft.

The bearing is a rolling bearing.

The submersible motor is connected with a low-temperature cable, and the low-temperature cable is connected with the atmospheric side power cable through an electrical penetration joint.

The submersible motor and the submersible pump are suspended at the lower end of the pump tower through the pump tower bracket.

The front end of the inlet of the submersible pump is provided with an inducer.

A filtering device is arranged at the inlet of the submersible pump.

The outlet end of the submersible pump is connected to the outlet pipe through an outlet elbow, and a check valve is arranged on the outlet elbow.

Compared with the prior art, the utility model adopts a submersible structure in which the pump and the motor are integrally connected, without a coupling, which reduces failures caused by misalignment between the pump and the coupling; the pump in the utility model It is integrally installed with the motor at the lower end of the pump tower in the large cabin conveying LNG, alkanes, hydrocarbons and other media. The submersible motor is used. Since the submersible motor is directly immersed in the pumping medium, there is no oxygen in the medium, so the motor does not Explosion-proof is required, and the safety is higher; ordinary vertical pumps, in order to prevent the medium in the pump from leaking outward, must use dynamic seals to seal the shaft, because it cannot achieve zero leakage, and there is a danger caused by seal leakage. The pump set in the new model has no dynamic seal. Since the motor is submersible, it can prevent the medium in the pump from leaking to the environment; Additional heat dissipation is provided for the motor of the pump. Compared with the air-cooled or water-cooled form of ordinary motors, the cooling effect is better, and at the same time, it saves engineering consumption, space and cost.

Description of drawings

Fig. 1 is the overall structural representation of the utility model;

Fig. 2 is a schematic diagram of the cooling circuit of the submersible motor of the present invention;

Fig. 3 is a partial enlarged view of I in Fig. 2 .

In the figure: 1-bottom of the cabin, 2-submersible motor, 3-pump tower support, 4-low temperature cable junction box, 5-low temperature cable, 6-low temperature cable fixing device, 7-outlet elbow, 8-one-way valve , 9-Exit pipe, 10-Cabin top, 11-Electrical penetration joint, 12-Atmosphere side power cable, 13-Junction box, 14-Filter screen, 15-Inducing wheel, 16-Overcurrent component, 17-Axial force Balance device, 18-motor stator, 19-balance circuit, 20-motor rotor, 21-impeller, 22-balance drum, 23-balance disc.

detailed description

Below in conjunction with embodiment the utility model is described in detail:

Example 1

The vertical cryogenic marine submersible pump shown in Figure 1 and Figure 2 includes a submersible motor 2 and a submersible pump. The submersible motor 2 is connected to a low-temperature cable 5. 2 Including the motor shaft, motor chamber and motor housing, the motor stator 18 is fixedly installed in the motor housing, the electronic rotor 20 is covered on the motor shaft, the motor shaft is equipped with rolling bearings, and the submersible pump includes the impeller arranged in the flow-passing part 21. The impeller cover plate and the axial force balance device 17, the axial force balance device 17 is located between the submersible motor 2 and the impeller 21; the impeller 21 is coaxial with the submersible motor 2, and the outlet end of the impeller 21 is balanced by the axial force The gap on the device 17 communicates with the motor chamber, and the motor chamber is provided with a balance circuit 19 and the inlet end of the balance circuit 19 is located in the motor chamber.

The submersible motor 2 and the submersible pump are integrally packaged and suspended at the lower end of the pump tower close to the bottom 1 of the cabin through the pump tower bracket 3. Most of the conveyed liquid is conveyed to the lower-level equipment through the outlet end of the submersible pump, and the conveyed liquid passes through the outlet elbow 7 is output to the outlet pipe 9, and a one-way valve 8 is installed on the outlet elbow 7. The transported liquid flows out from the impeller 21, and part of the liquid enters the axial force balance device 17 through the gap between the impeller 21 and the shell of the submersible motor 2, enters the motor room of the submersible motor 2 through the axial force balance device 17, and then passes through the motor room The balance loop 19 returns to the cabin or directly enters the lower-level equipment to form a complete submersible motor cooling loop.

The axial force balance device shown in Figure 3 includes a balance drum 22 and a balance disc 23. The balance drum 22 is located at the junction of the impeller cover plate and the flow-passing component 16 and is fixed on the impeller cover plate. There is a gap between the components 16; the balance disc 23 is located between the impeller cover plate and the motor housing, the balance disc 23 is fixed on the motor housing, and there is a gap connecting the motor chamber between the balance disc 23 and the motor housing . The axial force balance device 17 adopts the combination of the balance disc 23 which can be continuously and automatically adjusted and the balance drum 22, which can basically completely balance the axial force, make the bearing run under a small thrust load, and prolong the service life of the bearing. The balance disc 23 Compact structure and easy maintenance.

Compared with the ordinary vertical pump in which the motor and the pump are installed through the intermediate coupling, the structure of the utility model adopts the submersible structure in which the pump and the motor are integrated without a coupling, which reduces the misalignment of the pump and the coupling. caused by the failure. The pump and the motor are integrally installed at the lower end of the pump tower in large cabins such as large LNG, alkanes, and hydrocarbons. Since the conveying medium is flammable and explosive, the vertical pump with an external motor has explosion-proof requirements for the motor. The submersible motor is adopted, because there is no oxygen in the medium, the motor does not need to be explosion-proof, and the safety is higher.

The submersible motor in this utility model is directly immersed in the pumping medium, the cooling liquid of the submersible motor is the pumping medium, and the pumping medium enters the motor chamber from the outlet end of the impeller 21 through the balance drum 22 and the balance disc 23, and then Return to the cabin through the low-temperature cable junction box 14 or the motor shaft, where the motor shaft is selected as a hollow shaft. In order to ensure that the heat between the motor stator 18 and the motor rotor 20 is taken away in time during operation, the flow rate of the submersible motor coolant is also analyzed and calculated in detail to ensure that the motor is in a good cooling state. Compared with the air-cooled or water-cooled form of ordinary motors, this structure has a better cooling effect and saves engineering consumption.

For ordinary vertical pumps, the bearings need to be lubricated by adding grease or lubricating oil, and the amount of grease or lubricating oil added has a great influence on the life of the bearings. In this utility model, the pump set uses rolling bearings, and the pump set The transmission medium is directly cooled and lubricated, which reduces the failure problems caused by the quality and amount of lubricating grease or lubricating oil used.

Example 2

The basic structure of embodiment 2 is the same as that of embodiment 1, and this embodiment provides a preferred solution to improve the working efficiency of the submersible pump.

The inlet port of the balancing circuit 19 is located in the motor chamber. The return pipeline of the balance circuit 19 is arranged outside the motor housing or inside the submersible motor housing; when the motor shaft is an electric hollow shaft, the return pipeline of the balance circuit 19 can also be arranged inside the motor shaft. Various balancing circuits 19 can reduce the overall volume of the equipment and occupy less space.

The submersible motor is connected to the low-temperature cable 5, and the low-temperature cable 5 is connected to the power cable 12 on the atmospheric side through the electrical penetration joint 11 arranged on the top 10 of the cabin. At the connection between the low-temperature cable 5 inside the submersible pump and the power cable 12 on the external atmospheric side, an electrical penetration joint 11 is used. This joint adopts the gas sealing technology of metal and ceramic welding, metal and glass packaging, and is also used for power transmission. It prevents the pumped flammable and explosive medium from leaking along the low-temperature cable to the junction box 13 outside the cabin, achieves zero leakage of the medium, and makes the seal more secure and reliable. Improve the safety and reliability of the whole machine operation. The low-temperature cable 5 is fixed by a special cable fixing device 6 to avoid large swings during installation and operation, and collision with the pump tower and the inner wall of the cabin to generate sparks.

A filter screen 14 is provided at the inlet of the submersible pump, which can prevent possible impurities from entering the pump, thereby prolonging the maintenance period of the pump.

The front end of the inlet of the submersible pump is provided with an inducer 15, which is beneficial to improving the cavitation resistance of the submersible pump.

During the installation process, the overall installation method of the pump tower is adopted. Before the installation of the pump tower, the submersible pump and the submersible motor have been installed at the lower end of the pump tower, and then the whole pump tower is hoisted and installed in the cabin.

Claims (10)

1. Vertical low-temperature marine submersible pump, including submersible motor and submersible pump. The submersible motor includes a motor shaft, a motor room and a motor housing. The motor shaft is equipped with a bearing. The impeller, the impeller cover plate and the axial force balance device are characterized in that: the submersible motor and the submersible pump are integrally packaged and installed at the lower end of the pump tower in the cabin, and the axial force balance device is located between the submersible motor and the impeller Between; the impeller is coaxial with the submersible motor, the outlet end of the impeller communicates with the motor chamber through the gap on the axial force balance device, the motor chamber is provided with a balance circuit and the inlet end of the balance circuit is located in the motor chamber. 2. The vertical cryogenic marine submersible pump according to claim 1, characterized in that: the axial force balance device includes a balance drum and a balance disc, the balance drum is located at the connection between the impeller cover plate and the flow-passing component and fixed On the impeller cover plate, there is a gap between the balance drum and the flow-passing parts; the balance disc is located between the impeller cover plate and the motor housing, the balance disc is fixed on the motor housing, and the gap between the balance disc and the motor housing There is a gap to communicate with the motor room. 3. The vertical low-temperature marine submersible pump according to claim 1, characterized in that: the coolant of the submersible motor is the pumping medium, the inlet of the coolant is located in the motor chamber, and the outlet is connected through a low-temperature cable The inside of the box or the motor shaft is connected to the cabin, and the motor shaft is a hollow shaft. 4. The vertical cryogenic marine submersible pump according to claim 1, characterized in that: the return pipeline of the balance circuit is arranged outside the motor casing or inside the submersible motor casing, or inside the motor shaft , the motor shaft is a hollow shaft. 5. The vertical cryogenic marine submersible pump according to any one of claims 1-4, wherein the bearing is a rolling bearing. 6. The vertical cryogenic marine submersible pump according to any one of claims 1-4, characterized in that: the submersible motor is connected to a low-temperature cable, and the low-temperature cable is connected to the atmospheric side power cable through an electrical penetration joint. 7. The vertical cryogenic marine submersible pump according to any one of claims 1-4, wherein the submersible motor and the submersible pump are suspended and fixed at the lower end of the pump tower by a pump tower bracket. 8. The vertical cryogenic marine submersible pump according to any one of claims 1-4, characterized in that: the front end of the inlet of the submersible pump is provided with an inducer. 9. The vertical cryogenic marine submersible pump according to any one of claims 1-4, characterized in that: a filter device is arranged at the inlet of the submersible pump. 10. The vertical cryogenic marine submersible pump according to any one of claims 1-4, characterized in that: the outlet end of the submersible pump is connected to the outlet pipe through an outlet elbow, and a check valve is arranged on the outlet elbow .