A vertical condensate pump with motor self-cooling function

Abstract

This invention discloses a vertical condensate pump with a self-cooling motor, relating to the field of condensate pump technology. It includes a drive motor, a rotor shaft, a pump body, and a water collection shroud. The drive motor comprises a motor rotor and a motor stator that are fitted together. A through-type motor cooling channel is formed along the rotor shaft. An axial water intake channel is formed at one end of the rotor shaft, and the rotor shaft and motor rotor are coaxially connected. The outlet of the axial water intake channel communicates with the inlet of the motor cooling channel. Multiple radial water intake holes communicating with the inlet of the axial water intake channel are formed along the circumference of the rotor shaft sidewall. The pump body is coaxially fitted outside the rotor shaft and has a pump body inlet and a pump body outlet. The water collection shroud is fitted at the outlet of the motor cooling channel, and the water collection shroud flows to downstream equipment via a drainage pipe connected to the pump body outlet. This invention provides a dual-use water cooling solution, achieving fanless, extremely low-power drive cooling.

Description

Technical Field

[0001] This invention relates to the field of condensate pump technology, and more particularly to a vertical condensate pump with a self-cooling motor function. Background Technology

[0002] Vertical condensate pumps are core auxiliary equipment in the condensing systems of thermal power plants and nuclear power plants. Their function is to extract condensate from the condenser hot well, pressurize it, and then send it to the deaerator via a low-pressure heater. The condensate pump operates in a high-temperature and high-humidity environment for a long time. The pump body is submerged in the condenser hot well (40-60℃ saturated water), and the heat is continuously conducted upwards through a rigid coupling; at the same time, the motor itself generates a large amount of heat.

[0003] Traditional condensate pump motors rely on forced air cooling via a tail fan, which has the following inherent drawbacks:

[0004] 1. Low heat dissipation efficiency and significant temperature rise problem: Condensate pumps are usually installed in pump pits with poor ventilation. The original condensate pump motor relies solely on the axial flow fan blades mounted on the rotor for cooling, which has limited heat dissipation capacity and cannot effectively dissipate the heat generated by the motor.

[0005] 2. Significant thermal hysteresis effect: Fan cooling can only reduce the temperature of the motor casing. For the stator winding, where the heat is most concentrated, the cooling path is long (winding → core → casing → air), resulting in a significant thermal hysteresis effect and making it easy to form local hot spots. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a vertical condensate pump with a self-cooling function for the motor, thereby solving the technical problem that the existing condensate pump motor relies on a tail fan for forced air cooling, resulting in unsatisfactory heat dissipation.

[0007] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0008] This invention provides a vertical condensate pump with a self-cooling motor function, comprising:

[0009] A drive motor, including a motor rotor and a motor stator that are fitted together, wherein a through-type motor cooling channel is provided on the shaft of the motor rotor;

[0010] The rotor shaft has an axial water intake channel at one end, which is coaxially connected to the motor rotor. The outlet of the axial water intake channel is connected to the inlet of the motor cooling channel. The side wall of the rotor shaft has a plurality of radial water intake holes that are connected to the inlet of the axial water intake channel.

[0011] The pump body is coaxially sleeved outside the rotor shaft. The pump body has a pump body inlet at the other end of the rotor shaft away from the axial water intake channel outlet, and a pump body outlet at the same end as the axial water intake channel outlet.

[0012] A water collection cover is fitted onto the outlet of the motor cooling channel. A drainage pipe is connected to the bottom of the water collection cover. The drainage pipe and the pump body outlet converge to the downstream equipment.

[0013] Optionally, the inner wall of the motor cooling channel is provided with a rear spiral guide rib to make the working fluid flow in a spiral shape; the inner wall of the axial water intake channel is provided with a front spiral guide rib corresponding to the rear spiral guide rib.

[0014] Optionally, based on the flow direction of the working fluid in the axial water intake channel, the radial water intake hole is located after the last stage impeller on the rotor shaft and forms an angle of 30-60 degrees with the axis of the rotor shaft.

[0015] Optionally, the outlet of the motor cooling channel is provided with a water spray head, and the side wall of the water spray head is provided with a plurality of radial water spray holes along the circumference. The radial water spray holes are inclined at 5-10 degrees along the vertical plane of the motor cooling channel toward the drive motor.

[0016] Optionally, the highest point of the water collection hood is equipped with a drain valve and an overflow valve.

[0017] Optionally, the bottom of the water collection hood is also connected to a return water pipe, which flows back to the pump body inlet via the condenser; a drain solenoid valve and a return water solenoid valve are respectively installed on the drain pipe and the return water pipe, and a temperature sensor is installed on the drive motor.

[0018] When the temperature sensor readings exceed the temperature threshold, the drain solenoid valve is closed and the return water solenoid valve is opened.

[0019] When the temperature sensor reading is less than or equal to the temperature threshold, the drain solenoid valve is opened and the return water solenoid valve is closed.

[0020] Optionally, a U-shaped water seal structure is provided at the lowest point of the return water pipe between the water collection hood and the condenser.

[0021] Optionally, an auxiliary pipeline is also connected to the bottom of the water collection hood, and the auxiliary pipeline returns to the water inlet of the pump body;

[0022] An auxiliary solenoid valve is installed on the auxiliary pipeline, and a level gauge is installed inside the water collection hood; when the level value of the level gauge exceeds the level threshold, the auxiliary solenoid valve is opened.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0024] This invention provides a vertical condensate pump with a self-cooling function for the motor, organically integrating the water circulation of the vertical condensate pump with the cooling of the drive motor, achieving dual-use of water. The working fluid serves as both the main medium for the pump body and the cooling medium for the electric drive motor, significantly improving system integration. Furthermore, a return water pipeline is added so that when the drive motor's heat dissipation is insufficient, the cooling working fluid is cooled by a condenser and returned to the pump body inlet, reducing the inlet temperature and thus improving the drive motor's heat dissipation performance. Compared to traditional fan cooling methods, the pump structure is more compact, significantly reducing footprint and environmental noise. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of a vertical condensate pump with motor self-cooling function provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the cooling structure at the drive motor end provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the water collection cover return pipeline provided in an embodiment of the present invention;

[0028] The diagram is marked as follows:

[0029] 1. Drive motor; 11. Motor rotor; 12. Motor stator; 13. Motor cooling channel; 14. Rear spiral guide rib; 15. Temperature sensor;

[0030] 2. Rotor shaft; 21. Axial water intake channel; 22. Radial water intake hole; 23. Front section spiral guide ribs; 24. Last stage impeller;

[0031] 3. Pump body; 31. Pump body inlet; 32. Pump body outlet;

[0032] 4. Water collection hood; 41. Drain valve; 42. Level gauge; 43. Overflow valve;

[0033] 5. Drainage pipes; 51. Drainage solenoid valve;

[0034] 6. Return water pipeline; 61. Return water solenoid valve; 62. U-shaped water seal structure; 63. Condenser;

[0035] 7. Auxiliary piping; 71. Auxiliary solenoid valve;

[0036] 8. Spray head; 81. Radial spray hole. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device 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 the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] Example 1

[0041] like Figures 1 to 3 As shown, this embodiment of the invention provides a vertical condensate pump with motor self-cooling function, including a drive motor 1, a rotor shaft 2, a pump body 3, and a water collection cover 4.

[0042] (1) The drive motor 1 includes a motor rotor 11 and a motor stator 12 that are installed together. The motor rotor 11 has a through motor cooling channel 13 on its shaft.

[0043] The inner wall of the motor cooling channel 13 is provided with a rear spiral guide rib 14 that makes the working fluid flow in a spiral shape; the centrifugal force makes the working fluid stick to the inner wall of the motor cooling channel 13, which is conducive to enhancing the heat exchange effect between the working fluid and the motor rotor 11 and improving the cooling efficiency; at the same time, the air gap between the motor rotor 11 and the motor stator 12 can be controlled at 2-5mm. When the motor rotor 11 is running, the air in the air gap is violently disturbed, forming a heat exchange interface with high turbulence intensity.

[0044] (2) An axial water intake channel 21 is provided at one end of the rotor shaft 2 along the axis. The rotor shaft 2 and the motor rotor 11 are coaxially connected. The outlet of the axial water intake channel 21 is connected to the inlet of the motor cooling channel 13. Multiple radial water intake holes 22 are provided on the side wall of the rotor shaft 2 along the circumference, which are connected to the inlet of the axial water intake channel 21.

[0045] The axial water intake channel 21 has the same dimensions as the motor cooling channel 13. At the same time, the inner wall of the axial water intake channel 21 is provided with a front spiral guide rib 23 corresponding to the rear spiral guide rib 14, which plays the same role in improving the heat exchange effect.

[0046] Based on the flow direction of the working fluid in the axial water intake channel 21, the radial water intake hole 22 is located after the last stage impeller 24 on the rotor shaft 2, and forms an angle of 30-60 degrees with the axis of the rotor shaft 2. The rotor shaft 2 is equipped with multiple stages of impellers. There is a high-pressure section on the rotor shaft 2 after the last stage impeller 24 and before the pump outlet flange. By setting the radial water intake hole 22 in the high-pressure section and setting the radial water intake hole 22 at an angle, it is beneficial that when the working fluid moves from the pump body inlet 31 to the pump body outlet 32, a portion of the working fluid enters the axial water intake channel 21 through the radial water intake hole 22, which serves as the refrigerant for cooling the subsequent drive motor 1.

[0047] The rotor shaft 2 and the motor rotor 11 can be connected by a coupling and / or an intermediate shaft. The coupling and / or the intermediate shaft are hollow structures, and their inner holes are connected to the axial water intake channel 21 in the rotor shaft 2 and the motor cooling channel 13 in the motor rotor 11, respectively, to form a continuous cooling medium channel.

[0048] The radial water intake holes 22 can be set in multiple groups and evenly arranged along the circumference to form a redundant water intake structure.

[0049] (3) The pump body 3 is coaxially sleeved outside the rotor shaft 2. The pump body 3 has a pump body inlet 31 at the other end of the rotor shaft 2 away from the outlet of the axial water intake channel 21, and a pump body outlet 32 ​​is opened near the outlet of the axial water intake channel 21.

[0050] (4) The water collection cover 4 is installed at the outlet of the motor cooling channel 13. The bottom of the water collection cover 4 is connected to the drainage pipe 5. The drainage pipe 5 and the pump body outlet 32 ​​converge to the downstream equipment.

[0051] The vertical condensate pump provided in this embodiment is applied to the steam turbine thermal system. The drain pipe 5 and the pump body outlet 32 ​​are connected to the shaft seal heater. The shaft seal heater is the core energy-saving equipment of the steam turbine thermal system. Its main function is to recover the steam leakage from the shaft seal and use its heat to heat the condensate, thereby reducing the loss of working fluid and heat energy.

[0052] In summary, the vertical condensate pump provided by this invention organically integrates the water circulation of the vertical condensate pump with the cooling of the drive motor 1, achieving dual use of water. The working fluid is both the main medium of the pump body 3 and the cooling medium of the electric drive motor, greatly improving the system integration.

[0053] In order to further improve the heat dissipation performance of the drive motor 1, the bottom of the water collection cover 4 is also connected to the return water pipe 6, which flows back to the pump body inlet 31 via the condenser 63; the drain pipe 5 and the return water pipe 6 are respectively equipped with a drain solenoid valve 51 and a return water solenoid valve 61, and the drive motor 1 is equipped with a temperature sensor 15.

[0054] When the sensing data of temperature sensor 15 is greater than the temperature threshold, the drain solenoid valve 51 is closed and the return water solenoid valve 61 is opened.

[0055] When the sensing data of temperature sensor 15 is less than or equal to the temperature threshold, the drain solenoid valve 51 is opened and the return water solenoid valve 61 is closed.

[0056] The advantage of this setup is that when the primary solution already satisfies the heat dissipation of the drive motor 1, no intervention is required. Water entering through the pump inlet 31 flows through the pump body 3 and the motor cooling channel 13, eventually converging at the pump outlet 32 ​​and the drain outlet before entering downstream equipment. When the primary solution cannot meet the heat dissipation requirements of the drive motor 1, intervention is implemented. Water entering through the pump inlet 31 flows through the pump body 3 and enters downstream equipment, while another path flows through the motor cooling channel 13, enters the condenser 63 for cooling, and then returns to the pump inlet 31. This reduces the water temperature at the pump inlet 31 and improves the heat dissipation performance of the drive motor 1.

[0057] A U-shaped water seal structure 62 is provided at the lowest point of the return water pipe 6 between the water collection cover 4 and the condenser 63 to prevent vacuum leakage of the condenser 63.

[0058] An auxiliary pipe 7 is connected to the bottom of the water collection shroud 4, and the auxiliary pipe 7 returns to the pump body inlet 31. An auxiliary solenoid valve 71 is installed on the auxiliary pipe 7, and a level gauge 42 is installed inside the water collection shroud 4. When the level value of the level gauge 42 exceeds the level threshold, the auxiliary solenoid valve 71 is opened. The auxiliary pipe 7 is set up to prevent the liquid level inside the water collection shroud 4 from being too high, which would make it difficult for the working fluid in the motor cooling channel 13 to enter the water collection shroud 4, thus ensuring the normal operation of the motor cooling channel 13.

[0059] An air vent valve 41 is installed at the highest point of the water collection hood 4 to expel the air accumulated inside the water collection hood 4 and ensure smooth drainage. The air vent valve 41 remains closed during normal operation.

[0060] An overflow valve 43 is installed at the highest point of the water collection hood 4. When the drainage pipe 5, return water pipe 6 and auxiliary pipe 7 are completely blocked, the overflow will flow into the ditch, which will protect the water collection hood 4 on the one hand and be visible to the operators on the other.

[0061] (5) The spray head 8 is located at the outlet of the motor cooling channel 13. The side wall of the spray head 8 is provided with multiple radial spray holes 81 along the circumference. The radial spray holes 81 are inclined at 5-10 degrees along the vertical plane of the motor cooling channel 13 towards the drive motor 1.

[0062] The nozzle 8 is internally connected to the motor cooling channel 13. The working fluid discharged from the motor cooling channel 13 is thrown downwards at an angle by centrifugal force through the radial spray holes 81. After contacting the inner wall of the water collection shroud 4, the working fluid flows downwards and converges, achieving efficient water collection. The cross-section of the water collection shroud 4 can be C-shaped, directly attached to the nozzle 8. The motor rotor 11 extends from the center of the C-shape, and the working fluid ultimately converges at the end of the C-shape (the end being the lowest point). The water collection shroud 4 and the nozzle 8 can be connected by a labyrinth seal to prevent the working fluid from flowing out of the water collection shroud 4 and directly onto the drive motor 1. This non-contact water collection method, using radial spraying and a surrounding water collection ring, completely eliminates the rotary dynamic seal, preventing the risk of air intake (vacuum disruption) caused by wear and leakage from the rotary joint, making it particularly suitable for high-vacuum systems.

[0063] The vertical condensate pump provided in this invention can be widely used in thermal power plants, nuclear power plants, industrial circulating water systems, and other applications requiring vertical long-shaft pumps. Its outstanding motor cooling effect, extremely low power consumption, extremely low leakage risk, and multi-layered safety redundancy significantly improve equipment reliability and system economy, demonstrating excellent industrial applicability and promotional value.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vertical condensate pump with a self-cooling motor, characterized in that, include: A drive motor, including a motor rotor and a motor stator that are fitted together, wherein a through-type motor cooling channel is provided on the shaft of the motor rotor; The rotor shaft has an axial water intake channel at one end, which is coaxially connected to the motor rotor. The outlet of the axial water intake channel is connected to the inlet of the motor cooling channel. The side wall of the rotor shaft has a plurality of radial water intake holes that are connected to the inlet of the axial water intake channel. The pump body is coaxially sleeved outside the rotor shaft. The pump body has a pump body inlet at the other end of the rotor shaft away from the axial water intake channel outlet, and a pump body outlet at the same end as the axial water intake channel outlet. A water collection cover is fitted onto the outlet of the motor cooling channel. A drainage pipe is connected to the bottom of the water collection cover. The drainage pipe and the pump body outlet converge to the downstream equipment.

2. The vertical condensate pump having a motor self-cooling function according to claim 1, characterized by, The inner wall of the motor cooling channel is provided with a rear spiral guide rib that causes the working fluid to flow in a spiral shape; the inner wall of the axial water intake channel is provided with a front spiral guide rib that corresponds to the rear spiral guide rib.

3. The vertical condensate pump with motor self-cooling function according to claim 1, characterized in that, Based on the flow direction of the working fluid in the axial water intake channel, the radial water intake hole is located after the last stage impeller on the rotor shaft and forms an angle of 30-60 degrees with the axis of the rotor shaft.

4. The vertical condensate pump with motor self-cooling function according to claim 1, characterized in that, The motor cooling channel outlet is provided with a water spray head, and the side wall of the water spray head has multiple radial water spray holes along the circumference. The radial water spray holes are inclined at 5-10 degrees along the vertical plane of the motor cooling channel toward the drive motor.

5. The vertical condensate pump with motor self-cooling function according to claim 1, characterized in that, The highest point of the water collection hood is equipped with a drain valve and an overflow valve.

6. The vertical condensate pump with motor self-cooling function according to claim 1, characterized in that, The bottom of the water collection hood is also connected to a return water pipe, which flows back to the pump body inlet via the condenser; a drain solenoid valve and a return water solenoid valve are respectively installed on the drain pipe and the return water pipe, and a temperature sensor is installed on the drive motor. When the temperature sensor readings exceed the temperature threshold, the drain solenoid valve is closed and the return water solenoid valve is opened. When the temperature sensor reading is less than or equal to the temperature threshold, the drain solenoid valve is opened and the return water solenoid valve is closed.

7. The vertical condensate pump with motor self-cooling function according to claim 6, characterized in that, A U-shaped water seal structure is provided at the lowest point of the return water pipe between the water collection hood and the condenser.

8. The vertical condensate pump with motor self-cooling function according to claim 1, characterized in that, The bottom of the water collection hood is also connected to an auxiliary pipeline, which returns to the water inlet of the pump body. An auxiliary solenoid valve is installed on the auxiliary pipeline, and a level gauge is installed inside the water collection hood; when the level value of the level gauge exceeds the level threshold, the auxiliary solenoid valve is opened.

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