Dual-drive efficient high-reliability electric centrifugal pump set

Abstract

The utility model relates to a dual-drive high-efficiency high-reliability electric centrifugal pump set, which adopts a dual-drive motor to drive a centrifugal pump, the dual-drive motor consists of an asynchronous motor and a permanent magnet motor which are arranged in the same 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 utility model relates to an electric centrifugal pump group, in particular to a dual-drive electric centrifugal pump group. Background Art

[0002] Conventional electric pumps are controlled by an electronic control box. When the pump unit needs to operate, the control box directly connects the input power frequency power to the motor. The motor rotates, driving the pump rotor, which in turn rotates to achieve the purpose of liquid transportation. This type of pump unit can only adjust the flow rate by adjusting the pipeline resistance characteristics, that is, the opening of the pump outlet valve. This adjustment method can cause the pump unit to operate under abnormal conditions, reducing efficiency and increasing vibration and noise of the pump unit and outlet valve.

[0003] With increasing awareness of energy conservation, pump sets using frequency converters (VFDs) to control starting, stopping, and speed regulation are finding widespread use. The VFD converts input industrial power into variable-frequency power, driving the motor and pump set, thereby controlling the speed of the motor and centrifugal pump. For this type of pump set, flow regulation does not require changing the pipeline resistance characteristics. Instead, it adjusts the pump set's flow rate by varying the pump set's speed and adjusting its hydraulic performance. This regulation method allows the electric pump to consistently operate within its high-efficiency range at varying speeds, resulting in higher pump set efficiency and lower vibration and noise from the pump set and outlet valve. However, the VFD's complex internal structure and numerous electronic components, often numbering several thousand, reduce the reliability of the entire pump set. In some specialized applications, such as solar power generation and ship propulsion, a pump set failure and shutdown could potentially damage the system or cause a loss of power. Summary of the Invention

[0004] The utility model 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 noise of fixed frequency pump groups under off-state conditions.

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

[0006] Furthermore, 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.

[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 group 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 group 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 the 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 utility model are:

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

[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, thereby improving the mission reliability of the pump group and avoiding damage to the system caused by the pump group shutdown or causing emergency shutdown of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the principle of the dual-drive, high-efficiency, and high-reliability electric centrifugal pump set of the utility model;

[0014] Figure 2 This is a schematic diagram of the structure of the motor of the present utility model;

[0015] Explanation of the accompanying symbols: 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 with reference to the accompanying drawings and embodiments.

[0017] like Figure 1As shown in Figure 2, an embodiment of the present invention provides a dual-drive, high-efficiency, and high-reliability electric centrifugal pump assembly comprising a frequency converter 1, an electrical control box 2, an electric motor 3, and a centrifugal pump 4. The electric motor 3 houses an asynchronous motor stator 5 and an asynchronous motor rotor 6, forming an asynchronous motor; and a permanent magnet motor stator 7 and a permanent magnet motor rotor 8, forming 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 mounted in the same base. The frequency converter 1 is connected to the permanent magnet motor and is also connected to the asynchronous motor via the electrical 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 electrical control box 2 and inverter 1 receive power from the mains supply. Inverter 1 converts this power into variable-frequency power and supplies it to electrical control box 2. At this point, relay KM1 closes and relay KM2 closes. Electrical control box 2 then transmits the variable-frequency power from inverter 1 to permanent magnet motor stator 7. This generates a rotating magnetic field, driving permanent magnet motor rotor 8, which in turn rotates the rotor of centrifugal pump 4, thereby conveying the liquid medium. To adjust the pump flow rate, the output frequency of inverter 1 can be adjusted to change the speed of centrifugal pump 4, thereby altering the hydraulic performance of the pump set and adjusting the flow rate. If inverter 1, permanent magnet motor stator 7, or permanent magnet motor rotor 8 fails, inverter 1 sends a fault signal to electrical control box 2. Relay KM1 opens, relay KM2 closes, and electrical control box 2 shuts off power from inverter 1 and directly supplies power to asynchronous motor stator 5. This generates a rotating magnetic field, driving asynchronous motor rotor 6, ensuring continued operation of the pump set.

[0020] The design steps of the dual-drive, high-efficiency, and high-reliability electric centrifugal pump set of the utility model 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 conventional design methods, lengthen the motor base and shaft, install the stator of the asynchronous motor and the stator of the permanent magnet motor in the same 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 unit. 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 utility model for solving the problems of low reliability of variable frequency pump groups and low efficiency and high vibration noise of fixed frequency pump groups under off-state conditions has the following features:

[0026] (1) The utility model adopts a frequency converter 1, a permanent magnet motor stator 7, and a permanent magnet motor rotor 8. When the pump unit 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 unit when it is operating under abnormal conditions and reduce vibration noise;

[0027] (2) The utility model 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 the 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, avoid damage to the system caused by the pump group shutdown or cause emergency shutdown of the system, and improve 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. The centrifugal pump is driven by a dual-drive motor. The dual-drive motor consists 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 electrical 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 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 the industrial frequency power to the asynchronous motor, ensuring that the pump group continues to operate and improving the mission reliability of the pump group.

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