Magnetic shielding energy-saving closed water pump system

Abstract

A magnetic shielding energy-saving closed water pump system comprises a high-voltage motor, a forced cooling system, a magnetic shielding speed regulator, a closed water pump and a control system. An output shaft of the high-voltage motor is connected to the magnetic shielding speed regulator, an output shaft of the magnetic shielding speed regulator is connected to the closed water pump, and the high-voltage motor drives the closed water pump to work through output of the magnetic shielding speed regulator. The magnetic shielding speed regulator comprises an external cooling assembly and an internal speed regulating assembly; the external cooling assembly is sleeved outside the internal speed regulation assembly, and the external cooling assembly is connected to the external cooling assembly through a pipeline; the service life of the original motor and water pump system is prolonged; the forced cooling structure is reliable in heat dissipation, low in noise and low in energy consumption; the adjustment is sensitive; the valve throttling loss in a pipeline is greatly reduced, and system regulating valve faults are reduced; the speed regulation structure is smaller, the structure is compact, field equipment installation is facilitated, more energy is saved, and the heat dissipation effect is reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of energy-saving permanent magnet speed regulation in power plants, and in particular relates to a magnetic shielding energy-saving closed water pump system. Background Art

[0002] In order to achieve the goals of carbon peak and carbon neutrality, according to the national comprehensive work plan for energy conservation and emission reduction, the plan requires the promotion of the "three-in-one" transformation of existing coal-fired power units, namely, coal-saving and consumption-reducing transformation, heating transformation, and flexibility transformation, and the continuous promotion of ultra-low emission transformation of coal-fired power units. Under the disadvantage of hydropower and wind power priority scheduling, the load rate of thermal power units has been greatly reduced, and the units frequently participate in peak load regulation or deep peak load regulation. The original auxiliary machine operating conditions use throttling regulation methods, which wastes energy seriously when running at low load, and have poor regulation characteristics. Frequent start and stop will cause impact damage to the plant power system and mechanical loads.

[0003] The closed water system of the thermal power unit is equipped with two closed water pumps to provide cooling water for the auxiliary equipment of the unit. One is in operation and the other is in standby during normal operation. In the design, water pumps are usually equipped according to the maximum demand and a certain margin is left. In actual operation, the demand for closed water flow varies with the seasonal temperature and unit load. Therefore, in spring and autumn, especially in winter, the water temperature is low, and the closed water pump has a large margin. After the water pump is throttled, the design of the water pump deviates from the operating point and does not match the system pipeline curve. When it operates under the conditions of small flow and high head (compared with the original operating conditions), the pump-pipe pressure difference increases, the water pump is inefficient, and the energy consumption is seriously exceeded. Not only a large amount of electricity is wasted, but also the outlet valve has an increase in failures under the action of high water pressure for a long time. The existing closed water pump needs to be improved and the speed regulation and energy-saving technology is adopted.

[0004] In addition, in traditional permanent magnet speed regulation technology, the permanent magnet rotor and the conductor rotor produce axial movement during speed regulation to change the magnetic coupling area, and an axial magnetic pull is generated between the two rotors. This axial magnetic pull will act on the motor end or the water pump end. After the motor bearing or the water pump bearing is subjected to this additional axial force, the life span is greatly reduced. At the same time, the bearing of the speed regulator itself is also affected by this axial force, resulting in a reduced life span, increased failures, and increased maintenance. In addition, traditional permanent magnet speed regulation technology relies on the heat sink installed on itself for natural heat dissipation, but speed regulators with a power of more than 500KW need more heat sinks to increase the heat dissipation area due to the high heat generation, and the heat sink will consume more motor power, resulting in reduced energy saving. In some working conditions, there is even no energy saving after the transformation. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a method of reducing the output of the motor by using a forced cooling magnetic shielding speed reduction energy-saving technology, which can reduce power loss and improve the economy and reliability of the unit.

[0006] A magnetic shielding energy-saving closed water pump system, comprising a high-voltage motor, a strong cooling system, a magnetic shielding speed regulator, a closed water pump, and a control system; characterized in that:

[0007] The output shaft of the high-voltage motor is connected to the magnetic shielding speed regulator, the output shaft of the magnetic shielding speed regulator is connected to the closed water pump, and the high-voltage motor drives the closed water pump to work through the output of the magnetic shielding speed regulator;

[0008] The magnetically shielded speed regulator includes an external cooling component and an internal speed regulating component;

[0009] The external cooling component is sleeved on the outside of the internal speed regulating component, and the external cooling component is connected to the external cooling component through a pipeline.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] Magnetic shielding speed regulation technology saves energy. During speed regulation, the permanent magnet rotor and the conductor rotor have no relative axial movement, only the shielding sleeve moves, and there is no axial force, which increases the life of the original motor and water pump system. The strong cooling structure is used for reliable heat dissipation, low noise, and low energy consumption. The regulation is sensitive, and the control system field programmable gate array has a very fast processing speed, which is dozens of times faster than DCS.

[0012] By changing the coupling area through the shield sleeve, the size of the magnetic force is changed, thereby changing the torque transmitted from the motor to the closed water pump, and then adjusting the speed of the closed water pump. The throttling regulating valve in the closed water pump subsystem can be opened wider, such as the generator hydrogen cooler, generator fixed cooling water cooler, sealing oil cooler, steam turbine lubricating oil cooler, small machine lubricating oil cooler, thereby greatly reducing the valve throttling loss in the pipeline. The system throttling regulating valve is no longer under high water pressure for a long time, and the occurrence of failures is greatly reduced.

[0013] The internal speed regulating assembly adopts a compact structural arrangement scheme, cooperates with the strong cooling structure, and the cold air flows into the inner cavity. A heat sink is arranged in the inner cavity to realize the heat dissipation and structural fixing functions of the shielding sleeve, and the external heat sink is eliminated. Through the built-in heat dissipation, the rotational inertia of the speed regulating assembly is reduced, and more motor power is consumed, resulting in reduced energy saving. The existing scheme of the present application has a more miniaturized and compact structure, which is convenient for on-site equipment installation, more energy-saving, and reliable heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 System structure diagram

[0015] Figure 2 This is the structural diagram of the internal speed control components;

[0016] Figure 3 Schematic diagram of permanent magnet rotor

[0017] Figure 4 is a schematic diagram of a conductor rotor;

[0018] Figure 5 is a schematic diagram of a shielding sleeve;

[0019] Figure 6 It is a schematic diagram of the magnetic field when the permanent magnet is completely detached;

[0020] In the figure: permanent magnet rotor 1, conductor rotor 2, shielding sleeve 3, connecting sleeve 11, connecting sleeve 21, sliding sleeve 31, guide rod 32, heat sink 33, closed water pump 41, magnetic shielding speed regulator 42, strong cooling system 43, high voltage motor 44, control system 45. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings.

[0022] The technical solution adopted by the present invention is:

[0023] A magnetic shielding energy-saving closed water pump system includes a closed water pump 41, a magnetic shielding speed regulator 42, a strong cooling system 43, a high-voltage motor 44, and a control system 45.

[0024] The output shaft of the high-voltage motor 44 is connected to the magnetic shielding speed regulator 42 , the output shaft of the magnetic shielding speed regulator 42 is connected to the closed water pump 41 , and the high-voltage motor 44 drives the closed water pump 41 to work through the output of the magnetic shielding speed regulator 42 .

[0025] The magnetically shielded speed regulator 42 includes an external cooling component and an internal speed regulating component.

[0026] The external cooling assembly is connected to the forced cooling system 43 .

[0027] like Figure 2-5 As shown, the internal speed regulating assembly includes a shielding sleeve 3, a conductor rotor 2, and a permanent magnet rotor 1.

[0028] There is an air gap between the permanent magnet rotor 1 and the conductor rotor 2 , and the permanent magnet rotor 1 further comprises an axially movable shielding sleeve 3 , wherein the axially movable shielding sleeve 3 is disposed between the permanent magnet rotor 1 and the conductor rotor 2 .

[0029] The axially movable shielding sleeve 3 can be axially movable relative to the conductor rotor 2 .

[0030] The permanent magnet rotor 1 is cylindrical and is sleeved on the driving shaft of the closed water pump through an end connecting sleeve 11 .

[0031] The permanent magnet rotor is provided with permanent magnets evenly distributed along the circumference.

[0032] The connecting sleeve 11 is sleeved on the shaft of the water pump and connected with the shaft of the water pump by a key. The permanent magnet rotor 1 is cylindrical, and one end surface of the permanent magnet rotor 1 is fixed to the connecting sleeve 11 by bolts.

[0033] The conductor rotor 2 is also cylindrical and is sleeved onto the output shaft of the high-voltage motor via an end connection sleeve 21. The conductor rotor 2 is an annular copper conductor.

[0034] The conductor rotor 2 is mounted on the shaft of the motor through a connecting sleeve 21. The conductor rotor is cylindrical, and one end surface of the conductor rotor is fixed to the connecting sleeve by bolts.

[0035] The shielding sleeve 3 is cylindrical, and one end surface thereof is fixed on the sliding sleeve 31. The sliding sleeve 31 is sleeved on the connecting sleeve 21 of the conductor rotor 2, and can move axially along the connecting sleeve 21 of the conductor rotor, thereby driving the shielding sleeve 3 to move axially.

[0036] One end surface of the shielding sleeve 3 is also provided with evenly distributed mounting holes, and the mounting holes are used to mount the guide rods 32 .

[0037] At the same time, a corresponding guide hole is provided on one end face of the conductor rotor 2, and the guide rod 32 passes through the guide hole.

[0038] One end of the guide rod 32 is connected to a mounting hole on one end surface of the shielding sleeve 3 , and the other end is connected to the heat dissipation plate 33 .

[0039] The heat dissipation plate 33 is a plate-shaped structure, and evenly distributed mounting holes are processed on its outer circumference for mounting and connecting the guide rods 32 .

[0040] In addition, the heat dissipation plate 33 may be processed with sheet fins, which increase the heat dissipation area and the internal gas flowability. The heat dissipation plate 33 can be used to dissipate the heat generated by the shielding sleeve 3 through heat conduction and heat exchange.

[0041] The heat sink 33 is located in the inner cavity formed by the conductor rotor 2 and the permanent magnet rotor 1 .

[0042] A spoke structure is formed on the side end surface of the permanent magnet rotor 1 to ensure structural strength and provide an air flow passage inside so that the heat of the heat sink 33 can be dissipated through the air flow inside and outside.

[0043] In a specific implementation,

[0044] The external cooling assembly may include an external air induction shell. The forced cooling system 43 may use a forced cooling fan.

[0045] The external air induction shell is sleeved on the outside of the internal speed regulating component, and the external air induction shell is also connected to the air inlet of the forced cooling fan through a pipeline.

[0046] An air intake grid is arranged on the external air induced shell, and an air filter is installed on the air intake grid.

[0047] When the forced cooling fan is working, the external cold air flows in through the air inlet grid through the induced draft effect, passes through the spoke structure on the side end face of the permanent magnet rotor 1, enters the internal cavity, flows through the surface of the heat sink 33, and finally enters the forced cooling fan through the pipeline. The airflow passing through achieves heat dissipation for the conductor rotor, the permanent magnet rotor, and the shielding sleeve, especially for the shielding sleeve, which has a thin structure thickness and a small mass. Under the action of the magnetic field eddy current, it is easy to heat up and heats up quickly. Through the connected guide rod and heat sink, the heating speed of the shielding sleeve is significantly reduced.

[0048] As required, the heat dissipation plate 33 can be arranged in multiple layers, such as 2-3 layers, to further increase the heat dissipation area.

[0049] The shielding sleeve and the conductor rotor are assembled on the motor shaft extension end, the permanent magnet rotor is assembled on the closed water pump shaft extension end, and the shielding sleeve and the conductor rotor are inserted into the inner circumference of the permanent magnet rotor. The shielding sleeve is located in the air gap between the permanent magnet rotor and the conductor rotor, and can move axially to change the magnetic coupling area. The forced cooling fan is connected to the induced draft casing, which wraps the internal speed regulating components.

[0050] In other embodiments,

[0051] The external cooling assembly may include an external cooling shell. The forced cooling system 43 may use a forced cooling water pump.

[0052] The external cooling shell has a similar structural appearance to the external induced draft shell mentioned above.

[0053] The external cooling shell is provided with a cooling water pipe and is connected to a forced cooling water pump through a pipeline.

[0054] The external cooling shell is sleeved on the outside of the internal speed regulating component, and the external cooling shell cools the body through the cold water output by the strong cooling water pump. Furthermore, the external cooling shell and the internal speed regulating component exchange heat through the circulating airflow.

[0055] The forced cooling effect can be further improved by the water cooling provided by the external cooling shell and the forced cooling water pump.

[0056] The control system is used to control the axial movement of the magnetic shielding sleeve and the operation of the strong cooling system 43.

[0057] The axial movement of the magnetic shielding sleeve can be achieved by hydraulic or electric drive.

[0058] The above-mentioned closed water pumps are mainly used to supply water for the generator hydrogen cooler, generator cooling water cooler, sealing oil cooler, steam turbine lubricating oil cooler, small machine lubricating oil cooler, EH oil cooler, etc. on the machine side, the coal mill oil cooler on the furnace side, plasma cooling water, six large fan oil station coolers, air preheater guide bearing cooler and other equipment.

[0059] The principle of magnetic shielding speed regulator is: the permanent magnet rotor is installed on one side of the closed water pump, and the conductor rotor is installed on one side of the motor. The conductor rotor is covered by the permanent magnet rotor. The outer cylindrical surface of the conductor rotor is completely opposite to the inner cylindrical surface of the permanent magnet rotor. There is a certain gap between the two surfaces, which is the "air gap". A shielding sleeve is installed in the middle of the air gap. The shielding sleeve is a cylindrical component that rotates synchronously with the conductor rotor and can move axially at the same time.

[0060] like Figure 6 As shown in the figure, when the conductor rotor is not shielded by the shielding sleeve, the inner surface of the permanent magnet rotor obtains the highest magnetic field strength, that is, the magnetic flux of the magnetic field is the largest, and the load speed is the highest and the torque transmitted is the largest after the motor rotates. As the shielding sleeve is continuously inserted into the air gap, the magnetic field strength at the inner cylindrical surface of the permanent magnet rotor continues to decrease, the magnetic flux continues to decrease, and the speed of the permanent magnet rotor continues to decrease. Figure 2 As shown in the figure, when the shielding sleeve completely covers the conductor rotor, the speed of the permanent magnet rotor is the lowest. There is no relative displacement between the conductor rotor and the permanent magnet rotor, and there is no axial force on the motor and the load.

[0061] The magnetically shielded speed regulator can steplessly adjust the motor drive output, thus achieving energy saving.

[0062] Finally, it should be noted that the above description is only an explanation of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail, those skilled in the art can still modify the technical solutions described above or replace some of the technical features with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A magnetic shielding energy-saving closed water pump system, comprising a high-voltage motor, a strong cooling system, a magnetic shielding speed regulator, a closed water pump, and a control system; characterized in that: The output shaft of the high-voltage motor is connected to the magnetic shielding speed regulator, the output shaft of the magnetic shielding speed regulator is connected to the closed water pump, and the high-voltage motor drives the closed water pump to work through the output of the magnetic shielding speed regulator; The magnetically shielded speed regulator includes an external cooling component and an internal speed regulating component; The external cooling component is sleeved on the outside of the internal speed regulating component, and the external cooling component is connected to the external cooling component through a pipeline.

2. The magnetic shielding energy-saving closed water pump system according to claim 1 is characterized in that: The internal speed regulating components include a shielding sleeve, a conductor rotor, and a permanent magnet rotor; There is an air gap between the permanent magnet rotor and the conductor rotor, and the shielding sleeve is arranged between the permanent magnet rotor and the conductor rotor; The shielding sleeve is axially movable relative to the conductor rotor.

3. The magnetic shielding energy-saving closed water pump system according to claim 2 is characterized in that: The conductor rotor and the permanent magnet rotor are both cylindrical and have one end surface; The conductor rotor and the permanent magnet rotor are placed opposite to each other to form an internal cavity.

4. The magnetic shielding energy-saving closed water pump system according to claim 3 is characterized in that: The shielding sleeve is connected with a heat dissipation disk, and the heat dissipation disk is located in an internal cavity formed by the conductor rotor and the permanent magnet rotor.

5. The magnetic shielding energy-saving closed water pump system according to claim 4 is characterized in that: A corresponding guide hole is arranged on one end surface of the conductor rotor, and a guide rod passes through the guide hole; one end of the guide rod is connected to one end surface of the shielding sleeve, and the other end is connected to the heat dissipation plate.

6. The magnetic shielding energy-saving closed water pump system according to claim 4 is characterized in that: The side end surface of the permanent magnet rotor is processed to form a spoke structure to provide an air flow path for the internal cavity.

7. The magnetic shielding energy-saving closed water pump system according to claim 4 is characterized in that: The heat sink can also be processed with flaky fins.

8. The magnetic shielding energy-saving closed water pump system according to claim 4 is characterized in that: The heat sink can be provided with multiple layers.

9. The magnetic shielding energy-saving closed water pump system according to claim 1 is characterized in that: The external cooling components include an external draft casing, and the forced cooling system uses a forced cooling fan; The external air induction shell is sleeved on the outside of the internal speed regulating component, and the external air induction shell is also connected to the air inlet of the forced cooling fan through a pipeline.

10. The magnetic shielding energy-saving closed water pump system according to claim 1 is characterized in that: The external cooling assembly includes an external cooling shell, and the forced cooling system uses a forced cooling water pump; The external cooling shell is sleeved on the outside of the internal speed regulating component, and a cooling water pipe is arranged on the external cooling shell to be connected with a forced cooling water pump through a pipeline.

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