Dual-drive efficient high-reliability electric centrifugal pump set

Abstract

The invention relates to a dual-drive efficient high-reliability electric centrifugal pump set, a dual-drive motor is adopted to drive a centrifugal pump, the dual-drive motor is composed of an asynchronous motor and a permanent magnet motor which are arranged in the same machine base, and a frequency converter is connected with the permanent magnet motor and is connected with the asynchronous motor through an electric cabinet. The frequency converter is used for supplying power to the permanent-magnet motor, the electric cabinet is used for supplying power to the asynchronous motor, and the permanent-magnet motor or the asynchronous motor drives the centrifugal pump to operate through the rotating shaft. During normal operation, the asynchronous motor is not electrified, and the permanent magnet motor is controlled by the frequency converter to start, regulate the speed and stop, so that the efficiency of the pump set during operation under a bias working condition can be improved, and vibration noise is reduced. When the frequency converter or the permanent magnet motor breaks down, the frequency converter sends a fault signal to the electric control box, the electric control box cuts off an output power supply of the frequency converter, and directly outputs a power frequency power supply to the asynchronous motor, so that continuous operation of the pump set is ensured, the task reliability of the pump set is improved, and damage to a system or emergency shutdown of the system caused by shutdown of the pump set is avoided.

Description

Technical Field

[0001] The invention relates to an electric centrifugal pump set, in particular to a dual-drive electric centrifugal pump set. Background Art

[0002] Conventional electric pumps are started and stopped by an electric control box. When the pump unit needs to run, the electric control box directly connects the input power supply to the motor. The motor rotates to drive the pump rotor to rotate, and the pump rotor rotates to achieve the purpose of conveying liquid. This type of pump unit can only adjust the flow rate of the pump unit by adjusting the pipeline resistance characteristics, that is, the size of the pump outlet valve opening. This adjustment method will cause the pump unit to operate in an unsuitable condition, reduce efficiency, and increase the vibration and noise of the pump unit and outlet valve.

[0003] As people's awareness of energy conservation increases, pump sets that use frequency converters to control the start, stop, and speed of pump sets are used in many occasions. The frequency converter converts the input industrial frequency power supply into a variable frequency power supply to drive the motor and pump set to operate, thereby achieving the purpose of controlling the speed of the motor and centrifugal pump. For this type of pump set, the flow rate does not need to change the pipeline resistance characteristics, but the pump set flow rate is adjusted by changing the pump set speed and adjusting the pump set hydraulic performance. This adjustment method can make the electric pump always run in the high-efficiency area of ​​different speeds, the pump set has a high operating efficiency, and the pump set and outlet valve vibration noise is also small. However, due to the complex internal structure of the frequency converter and the large number of electronic components, which are often thousands, the reliability of the entire pump set is reduced. In some special occasions, such as solar power generation and ship power, the failure and shutdown of the pump set may cause system damage or loss of power. Summary of the invention

[0004] The present invention provides a dual-drive, high-efficiency and high-reliability electric centrifugal pump group, which is used to solve the problems of low reliability of variable frequency pump groups and low efficiency and high vibration and noise of fixed frequency pump groups under off-state conditions.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is: a dual-drive, high-efficiency and high-reliability electric centrifugal pump group, including a frequency converter, an electric control box, and a centrifugal pump. The centrifugal pump is driven by a dual-drive motor. The dual-drive motor is composed of an asynchronous motor and a permanent magnet motor in the same base. The frequency converter is connected to the permanent magnet motor and is connected to the asynchronous motor through the electric control box.

[0006] Furthermore, the asynchronous motor is composed of an asynchronous motor stator and an asynchronous motor rotor; the permanent magnet motor is composed of a permanent magnet motor stator and a permanent magnet motor rotor.

[0007] Furthermore, the asynchronous motor rotor and the permanent magnet motor rotor are coaxially mounted, and the asynchronous motor stator and the permanent magnet motor stator are mounted in the same machine base.

[0008] Furthermore, when the pump unit is operating normally, the frequency converter converts the industrial frequency power supply into a variable frequency power supply, supplies power to the motor through the electrical control box, controls the start, speed regulation, and stop of the permanent magnet motor, and can improve the efficiency of the pump unit when operating under abnormal conditions and reduce vibration and noise.

[0009] Furthermore, when the frequency converter fails, it sends a fault signal to the electric control box, which cuts off the variable frequency power output by the frequency converter and directly outputs industrial frequency power to the asynchronous motor, which can ensure that the pump group continues to operate and improve the mission reliability of the pump group.

[0010] The beneficial effects of the present invention are:

[0011] 1. When the pump group is operating normally, a permanent magnet motor is used to drive the centrifugal pump rotor, and the pump group has a high efficiency. When the pump group is operating under abnormal conditions, the output frequency of the inverter 1 is adjusted to adjust the flow rate of the pump group, thereby improving the efficiency of the pump group under abnormal conditions and reducing the vibration noise of the pump group;

[0012] 2. After the inverter fails, the electric control box directly outputs industrial frequency power to the asynchronous motor part of the motor to ensure that the pump group continues to operate, improve the mission reliability of the pump group, and avoid damage to the system caused by the pump group shutdown or cause emergency shutdown of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the principle of the dual-drive high-efficiency and high-reliability electric centrifugal pump set of the present invention;

[0014] Figure 2 It is a schematic diagram of the structure of the motor of the present invention;

[0015] Explanation of the accompanying drawings: 1-frequency converter, 2-electric control box, 3-motor, 4-centrifugal pump, 5-asynchronous motor stator, 6-asynchronous motor rotor, 7-permanent magnet motor stator, 8-permanent magnet motor rotor, A-industrial frequency power supply, B-variable frequency power supply, C-fault signal. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0017] like Figure 1 As shown in Figure 2, a dual-drive high-efficiency and high-reliability electric centrifugal pump group provided by an embodiment of the present invention comprises a frequency converter 1, an electric control box 2, a motor 3, and a centrifugal pump 4. The motor 3 is equipped with an asynchronous motor stator 5, an asynchronous motor rotor 6 to form an asynchronous motor, and a permanent magnet motor stator 7 and a permanent magnet motor rotor 8 to form a permanent magnet motor. The asynchronous motor rotor 6 and the permanent magnet motor rotor 8 are coaxial, and the asynchronous motor stator 5 and the permanent magnet motor stator 7 are installed in the same base. The frequency converter 1 is connected to the permanent magnet motor, and is connected to the asynchronous motor through the electric control box 2.

[0018] The frequency converter 1 has a fault signal C output function. The electric control box 2 can receive the fault signal C output by the frequency converter 1, cut off the variable frequency power supply B output by the frequency converter, and directly provide the industrial frequency power supply A to the asynchronous motor.

[0019] During normal operation, both the electric control box 2 and the frequency converter 1 have industrial frequency power input, and the frequency converter 1 converts the industrial frequency power into variable frequency power and transmits it to the electric control box 2. At this time, the relay KM1 is energized, and the relay KM2 is disconnected. The electric control box 2 transmits the variable frequency power transmitted by the frequency converter 1 to the permanent magnet motor stator 7. The permanent magnet motor stator 7 forms a rotating magnetic field, drives the permanent magnet motor rotor 8 to rotate, and then drives the rotor of the centrifugal pump 4 to rotate, so as to realize the transmission of the liquid medium. When the pump group needs to adjust the flow rate, the output frequency of the frequency converter 1 can be adjusted to change the speed of the centrifugal pump 4, thereby changing the hydraulic performance of the pump group, so as to achieve the purpose of adjusting the flow rate of the pump group. When the frequency converter 1, the permanent magnet motor stator 7 or the permanent magnet motor rotor 8 fails, the frequency converter 1 sends a fault signal to the electric control box 2, the relay KM1 is disconnected, the relay KM2 is energized, and the electric control box 2 cuts off the power output by the frequency converter 1, and directly outputs the industrial frequency power to the asynchronous motor stator 5. The asynchronous motor stator 5 forms a rotating magnetic field, drives the asynchronous motor rotor 6 to rotate, and ensures that the pump group continues to operate.

[0020] The design steps of the dual-drive high-efficiency and high-reliability electric centrifugal pump set of the present invention include:

[0021] The first step is to design a centrifugal pump according to conventional design methods.

[0022] The second step is to design the stator and rotor of the permanent magnet motor and the stator and rotor of the asynchronous motor according to the conventional design method, lengthen the length of the motor base and the shaft, install the stator of the asynchronous motor and the stator of the permanent magnet motor in one base, and install the rotor of the asynchronous motor and the rotor of the permanent magnet motor on the same shaft;

[0023] The second step is to design a frequency converter for the pump group. The frequency converter should have a fault signal output function.

[0024] The third step is to design an electric control box for the pump group. The electric control box should be able to receive the fault signal output by the inverter, cut off the variable frequency power output by the inverter, and directly provide industrial frequency power to the asynchronous motor.

[0025] The technical solution adopted by the present invention for solving the problems of low reliability of variable frequency pump group and low efficiency and high vibration noise of fixed frequency pump group under off-state conditions has the following characteristics:

[0026] (1) The present invention adopts a frequency converter 1, a permanent magnet motor stator 7, and a permanent magnet motor rotor 8. When the pump group is operating normally, the frequency converter controls the start, speed regulation, and stop of the permanent magnet motor, which can improve the efficiency of the pump group when it is operating under abnormal conditions and reduce vibration and noise;

[0027] (2) The present invention is equipped with an electric control box 2, an asynchronous motor stator 5, and an asynchronous motor rotor 6. The electric control box 2 can receive a fault signal output by the frequency converter 1. When the frequency converter 1 fails, the fault signal is sent to the electric control box 2. The electric control box 2 directly outputs the industrial frequency power supply to the asynchronous motor to ensure that the pump group continues to operate, avoids damage to the system caused by the pump group shutdown or causes the system to shut down urgently, and improves the mission reliability of the pump group.

Claims

1. A dual-drive, high-efficiency, high-reliability electric centrifugal pump set, characterized by: It includes a frequency converter, an electric control box, and a centrifugal pump. A dual-drive motor is used to drive the centrifugal pump. The dual-drive motor is composed of an asynchronous motor and a permanent magnet motor in the same base. The frequency converter is connected to the permanent magnet motor and is connected to the asynchronous motor through the electric control box.

2. The dual-drive, high-efficiency, high-reliability electric centrifugal pump set according to claim 1 is characterized in that: The asynchronous motor consists of an asynchronous motor stator and an asynchronous motor rotor; the permanent magnet motor consists of a permanent magnet motor stator and a permanent magnet motor rotor.

3. The dual-drive, high-efficiency, high-reliability electric centrifugal pump set according to claim 2 is characterized in that: The asynchronous motor rotor and the permanent magnet motor rotor are coaxially mounted, and the asynchronous motor stator and the permanent magnet motor stator are mounted in the same base.

4. The dual-drive, high-efficiency, high-reliability electric centrifugal pump set according to claim 1 is characterized in that: When the pump unit is operating normally, the frequency converter converts the industrial frequency power supply into variable frequency power supply, supplies power to the motor through the electric control box, controls the start, speed regulation and stop of the permanent magnet motor, improves the efficiency of the pump unit when operating under abnormal conditions, and reduces vibration and noise.

5. The dual-drive, high-efficiency, high-reliability electric centrifugal pump set according to claim 1 is characterized in that: When the inverter fails, it sends a fault signal to the electric control box, which cuts off the variable frequency power output by the inverter and directly outputs industrial frequency power to the asynchronous motor, which can ensure the continued operation of the pump group and improve the mission reliability of the pump group.

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