A high-load magnetic levitation pump with emergency stop and power-off protection device and its working method

Abstract

The present invention discloses a high-load magnetic levitation pump with an emergency stop and power-off protection device and a working method thereof. The magnetic levitation pump includes a rotor, a pump impeller, a pump housing, an emergency stop and power-off protection device, and a power supply module. In the present invention, when the AC power supply normally energizes the electromagnetic coil, the rotor rotates normally; and when a sudden power outage occurs, the power outage signal can be judged by the power outage detection module. At the same time, since the electromagnetic coil fixed to the pump housing is connected to the electromagnetic brake and the deceleration brake module, the back electromotive force current generated by the continued rotation of the rotor after the power outage is utilized. On the one hand, the electromagnetic coil is maintained to continue to generate an electromagnetic field, and on the other hand, the electromagnetic brake is used to decelerate the rotor; and the electromagnetic brake can be emergency braked through the emergency brake button, providing effective protection for sudden accidents.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic levitation pumps, and in particular relates to a high-load magnetic levitation pump with an emergency stop and power-off protection device and a working method thereof. Background Art

[0002] At present, the field of magnetic levitation pumps is mainly divided into two types of pumps: one is a magnetic levitation pump based on magnetic levitation bearings. This magnetic levitation pump uses two or more magnetic levitation bearings as the basis to realize the suspension control function of the rotor. A mechanical connection is used between the rotor and the impeller. The advantages of this structure are: (1) There is no mechanical connection in the driving part, low noise and low friction; (2) There is only contact and lubrication between the impeller and the pump casing, and the overall pollution is small; (3) The rotor and impeller are mechanically connected, which has higher reliability.

[0003] The other is a magnetic levitation bearingless pump based on active magnetic levitation technology. The pump impeller is suspended and driven by the magnetic field and is completely separated from the pump casing. It does not require any lubrication or sealing. The advantages of this structure are: (1) The pump impeller is completely suspended, there is no mechanical connection, no friction between structures, and low noise; (2) There is no mechanical connection between the impeller and the pump head casing, so the pump is wear-free, almost no particles are generated, and no lubrication is required, ensuring the purity of the liquid.

[0004] However, both magnetic bearings and active suspension technologies rely on electricity to maintain operation. If a power outage occurs during operation, the suspended pump impeller and magnetic bearing will lose control, causing the high-speed pump impeller and rotor to fall, causing serious damage to the equipment and potentially even a safety accident. Currently, to address unexpected power outages, the magnetic suspension system is typically equipped with an uninterruptible power supply (UPS). This allows the magnetic suspension pump to continue operating for a period of time after a power outage until it can safely shut down. However, UPSs are expensive and require regular maintenance, resulting in low overall economic benefits.

[0005] Furthermore, because the magnetic levitation pump requires deceleration before shutting down, and both the rotor and the liquid being transported possess significant kinetic energy, the rotor's speed is difficult to decelerate rapidly through its own cogging torque and friction, resulting in a long shutdown time. This makes it difficult to immediately shut down the pump in the event of an operational accident or other unexpected situation when transporting sensitive and hazardous liquids, exacerbating the losses caused by the accident. Therefore, it is necessary to design a safe, effective, and cost-effective technical solution to deal with potential power outages and emergencies. Summary of the Invention

[0006] In response to current technical needs, the present invention provides a high-load magnetic levitation pump with an emergency stop power-off protection device and a working method thereof. The power-off signal can be judged by a power-off detection module. At the same time, since the electromagnetic coil fixedly connected to the pump housing is connected to the electromagnetic brake and the deceleration brake module, the back electromotive force current generated by the continued rotation of the rotor after power failure is utilized. On the one hand, the electromagnetic coil is maintained to continue to generate an electromagnetic field, and on the other hand, the electromagnetic brake is used to decelerate the rotor. The electromagnetic brake can be emergency braked through the emergency brake button, providing effective protection for sudden accidents.

[0007] In order to achieve the above functions, the present invention adopts the following technical solutions:

[0008] The present invention provides a high-load magnetic levitation pump with an emergency stop and power-off protection device, comprising a rotor, a pump impeller, a pump casing, an emergency stop and power-off protection device and a power supply module; the permanent magnet on the rotor is suspended and driven by the magnetic field generated by an electromagnetic coil 1 fixedly connected to the pump casing; the pump impeller is fixed to the rotor and placed in the pump casing; the emergency stop and power-off protection device comprises an electromagnetic brake, a processor, a power-off detection module and a deceleration braking module; the electromagnetic brake comprises a top cover plate, an upper friction disc, a second electromagnetic coil, a base, a lower friction disc and a leaf spring; the top cover plate is fixed to the bottom of the rotor or the bottom of the pump impeller, the leaf spring connects the top cover plate and the upper friction disc, the base is fixedly connected to the pump casing, the second electromagnetic coil is placed in the base, and the lower friction disc is fixedly connected to the base; the upper friction disc is placed directly above the lower friction disc.

[0009] The power module outputs power supply 1 and power supply 2, and power supply 2 generates AC power via an inverter. The power failure detection module includes a capacitor, a DC-DC boost circuit, a comparator, a DC-DC buck circuit, and a DC-DC step-down circuit. One end of the capacitor, the power input end of the DC-DC step-down circuit, and the power input end of the comparator are all connected to power supply 1 output by the power module. The power output end of the DC-DC step-down circuit is connected to one power input end of the processor. The other end of the capacitor is connected to the power input end of the DC-DC boost circuit, and the power output end of the DC-DC boost circuit is connected to another power input end of the processor. The comparator communicates signals with the DC-DC boost circuit and transmits signals to the processor. The processor is connected to an emergency brake button.

[0010] The deceleration braking module includes relay 1 and relay 2; one end of electromagnetic coil 2 is connected to a contact of relay 1 and relay 2, and the other end is connected to electromagnetic coil 1 and one end of an AC power supply; the other end of electromagnetic coil 1 is connected to another contact of relay 1, another contact of relay 2 and the other end of the AC power supply; both ends of electromagnetic coil 3 of relay 1 and relay 2 are connected to a processor.

[0011] The working method of the high-load magnetic levitation pump with emergency stop and power-off protection device is as follows:

[0012] (1) When the AC power supply is energized to the electromagnetic coil 1, the rotor rotates; the voltage of the fully charged capacitor is lower than the system voltage, and the system voltage passes through the DC-DC step-down circuit to provide the voltage required by the processor; the comparator compares the system voltage and the voltage of the capacitor and outputs a high-level signal; at this time, the DC-DC boost circuit receives the high-level signal of the comparator and cannot play a boosting role, and the processor does not use the voltage provided by the capacitor; the processor receives the high-level signal of the comparator and does not start the brake shutdown. At this time, the processor outputs a low-level signal to relay 1 and relay 2, and relay 1 and relay 2 are both in the disconnected state. The electromagnetic coil 2 is not energized, the leaf spring is in a naturally stretched state, and the upper friction disc and the lower friction disc are in a separated state.

[0013] (2) When the AC power supply to electromagnetic coil 1 is suddenly cut off, the system voltage is lower than the voltage of the capacitor. After the comparator compares the system voltage with the voltage of the capacitor, it outputs a low-level signal; the DC-DC boost circuit receives the low-level signal from the comparator, achieves a boosting effect, and provides power to the processor after the electromagnetic coil 1 is powered off; after the processor receives the low-level signal from the comparator, it starts the parking brake and outputs a high-level signal to relay 1. After receiving the high-level signal, relay 1 is connected, and electromagnetic coil 1, relay 1 and electromagnetic coil 2 form a closed-loop circuit. After the electromagnetic coil 1 is powered off, the current generated by the rotor that is still rotating is connected to electromagnetic coil 2 through relay 1; at this time, electromagnetic coil 2 generates an axial electromagnetic field, causing the upper friction disk in the electromagnetic field to frictionally contact with the lower friction disk, which plays a role in decelerating the rotor and completing the rotor stop before the power of capacitor 1 is exhausted.

[0014] Preferably, when an accident occurs, the emergency brake button is manually triggered. After the processor receives the high-level signal from the emergency brake button, it starts the parking brake and outputs a high-level signal to relay 2. Relay 2 connects the AC power supply and electromagnetic coil 2. At this time, the voltage input from the AC power supply to the electromagnetic coil 2 is the rated voltage, and the friction force between the upper friction plate and the lower friction plate reaches the maximum state, thereby realizing the effect of rotor braking.

[0015] Preferably, at the initial moment when the AC power supply is cut off to the electromagnetic coil 1, since the rotor and the liquid being transported have large kinetic energy, the rotor speed is the largest, the current generated by the rotor rotation is the largest, and the corresponding current input to the electromagnetic coil 2 will be the highest. The braking capacity of the upper friction disk and the lower friction disk is the strongest at the initial moment, thereby achieving a rapid braking effect.

[0016] The present invention has the following beneficial effects:

[0017] 1. When the AC power supply is normally energized to the electromagnetic coil 1, the rotor of the present invention rotates normally; however, when a sudden power outage occurs, the present invention can quickly identify the power outage through the power outage detection module, and promptly connect the relay 1 of the deceleration brake module, so that the electromagnetic coil 1, relay 1 and electromagnetic coil 2 form a closed-loop circuit, and use the electric energy generated by the rotor's self-rotation after the power outage to maintain the electromagnetic coil 1 to continue to generate an electromagnetic field (the rotor cuts the closed-loop electromagnetic coil 1 to generate current in the electromagnetic coil 1, thereby generating an electromagnetic field). At the same time, the electromagnetic coil 2 generates an electromagnetic field to make the upper friction disk and the lower friction disk frictionally contact, thereby achieving the effect of rapid braking and power-off protection, and avoiding serious damage to the magnetic levitation pump due to power outage.

[0018] 2. The emergency brake button of the present invention can achieve emergency and rapid braking when an accident occurs during the transportation of sensitive or dangerous liquids, so as to reduce the losses caused by the accident. Moreover, since the emergency brake button uses the AC power generated by the power module, the braking effect of the emergency brake button on the electromagnetic brake is better than the braking effect of the electromagnetic brake under the power-off protection condition, and can maintain the optimal braking effect until the rotor stops rotating, providing effective protection for emergency braking in sudden accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a sectional perspective view of the overall structure of the magnetic levitation pump of the present invention.

[0020] Figure 2 It is a structural explosion diagram of the electromagnetic brake in the present invention.

[0021] Figure 3 It is a structural stereogram of the electromagnetic brake in the present invention.

[0022] Figure 4 This is a structural block diagram of the processor, power failure detection module and deceleration braking module in the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4As shown, a high-load magnetic levitation pump with an emergency stop and power-off protection device includes a rotor, a pump impeller, a pump housing, an emergency stop and power-off protection device and a power module; the permanent magnet on the rotor is suspended and driven by the magnetic field generated by an electromagnetic coil 1 fixedly connected to the pump housing; the pump impeller is fixed to the rotor and placed in the pump housing; the emergency stop and power-off protection device includes an electromagnetic brake, a processor, a power-off detection module and a deceleration braking module; the electromagnetic brake A includes a top cover plate 1, an upper friction disc 2, an electromagnetic coil 2 3, a base 4, a lower friction disc 5 and a leaf spring 6; the top cover plate 1 is fixed to the bottom of the rotor or the bottom of the pump impeller, the leaf spring 6 connects the top cover plate 1 and the upper friction disc 2, the base 4 is fixedly connected to the pump housing, the electromagnetic coil 2 3 is placed in the base 4, and the lower friction disc 5 is fixedly connected to the base 4; the upper friction disc 2 is placed directly above the lower friction disc 5.

[0025] The power module is connected to the power supply and outputs power supply 1 and power supply 2. Power supply 2 generates AC power through an inverter. The power failure detection module includes a capacitor, a DC-DC boost circuit, a comparator, a DC-DC buck circuit and a DC-DC step-down circuit. One end of the capacitor, the power input end of the DC-DC step-down circuit and the power input end of the comparator are all connected to power supply 1 output by the power module. The power output end of the DC-DC step-down circuit is connected to one power input end of the processor (the power supply end during normal power-on). The other end of the capacitor is connected to the power input end of the DC-DC boost circuit, and the power output end of the DC-DC boost circuit is connected to another power input end of the processor (the power supply end during power failure). The comparator communicates signals with the DC-DC boost circuit and transmits signals to the processor. The processor is connected to an emergency brake button. The DC-DC step-down circuit steps down the system voltage provided by Power Supply 1 to meet the voltage required by the processor during normal power-on. The capacitor charges when powered on and maintains a full charge. After a power outage, it briefly powers the processor via the DC-DC boost circuit. The DC-DC boost circuit boosts the capacitor voltage to meet the supply voltage required by the processor. The comparator compares the system voltage provided by Power Supply 1 with the capacitor voltage. When the system voltage is lower than the capacitor voltage, it outputs a low-level signal; when the system voltage is higher, it outputs a high-level signal. Triggering the emergency brake button in an emergency sends an emergency brake signal to the processor.

[0026] The deceleration braking module includes relay 1 and relay 2; one end of electromagnetic coil 2 3 is connected to a contact of relay 1 and relay 2, and the other end is connected to electromagnetic coil 1 and one end of the AC power supply; the other end of electromagnetic coil 1 is connected to another contact of relay 1, another contact of relay 2 and the other end of the AC power supply; both ends of electromagnetic coil 3 of relay 1 and relay 2 are connected to the processor.

[0027] The working method of the high-load magnetic levitation pump with emergency stop and power-off protection device is as follows:

[0028] (1) When the AC power supply is normally energized to electromagnetic coil 1, the rotor rotates; the voltage of the fully charged capacitor is lower than the system voltage, and the system voltage passes through the DC-DC step-down circuit to provide the voltage required by the processor when normally powered; the comparator compares the system voltage with the voltage of the capacitor and outputs a high-level signal. At this time, the DC-DC boost circuit receives the high-level signal from the comparator and cannot perform the boost function, and the processor does not use the voltage provided by the capacitor; the processor receives the high-level signal from the comparator and does not initiate the braking shutdown. At this time, the processor outputs a low-level signal to relay 1 and relay 2, and relay 1 and relay 2 are both in the disconnected state. Electromagnetic coil 2 3 is not energized, the leaf spring 6 is in a naturally stretched state, and the upper friction disc 2 and the lower friction disc 5 are in a separated state.

[0029] (2) When the AC power supply to electromagnetic coil 1 is suddenly cut off, the system voltage is lower than the voltage of the capacitor (reference base voltage). After the comparator compares the system voltage with the voltage of the capacitor, it outputs a low-level signal; the DC-DC boost circuit receives the low-level signal from the comparator, achieves the effect of boosting, and provides power to the processor for a short time after the power is cut off; after the processor receives the low-level signal from the comparator, it starts the parking brake and outputs a high-level signal to relay 1. After receiving the high-level signal, relay 1 is connected, and electromagnetic coil 1, relay 1 and electromagnetic coil 2 3 form a closed-loop circuit. The current generated by the rotor that is still rotating after the power is cut off is connected to electromagnetic coil 2 3 through relay 1; at this time, electromagnetic coil 2 3 generates an axial electromagnetic field, causing the upper friction disk 2 in the electromagnetic field to frictionally contact with the lower friction disk, which has the effect of quickly decelerating the rotor and completing the rotor stop before the power of capacitor 1 is exhausted.

[0030] (3) When an accident requires manual emergency braking, the emergency brake button is manually triggered. After the processor receives the high-level signal from the emergency brake button, it starts the parking brake and outputs a high-level signal to relay 2. Relay 2 connects the AC power supply and electromagnetic coil 2 3. At this time, the voltage input from the AC power supply to the electromagnetic coil 2 3 is the rated voltage, and the friction force between the upper friction disc 2 and the lower friction disc reaches the maximum state, achieving the effect of rapid braking of the rotor.

Claims

1. A high-load magnetic levitation pump with an emergency stop and power-off protection device, comprising a rotor, a pump impeller, a pump housing, an emergency stop and power-off protection device, and a power module; the permanent magnets on the rotor are suspended and driven by the magnetic field generated by an electromagnetic coil fixed to the pump housing; the pump impeller is fixed to the rotor and placed in the pump housing; the characteristics are: The emergency stop power-off protection device includes an electromagnetic brake, a processor, a power-off detection module, and a deceleration brake module; the electromagnetic brake includes a top cover plate, an upper friction disc, a second electromagnetic coil, a base, a lower friction disc, and a leaf spring; the top cover plate is fixed to the bottom of the rotor or the bottom of the pump impeller, the leaf spring connects the top cover plate and the upper friction disc, the base is fixed to the pump housing, the second electromagnetic coil is placed in the base, and the lower friction disc is fixed to the base; the upper friction disc is placed directly above the lower friction disc; The power module outputs power supply 1 and power supply 2, and power supply 2 generates AC power through an inverter; the power failure detection module includes a capacitor, a DC-DC boost circuit, a comparator, a DC-DC buck circuit and a DC-DC step-down circuit; one end of the capacitor, the power input end of the DC-DC step-down circuit and the power input end of the comparator are all connected to power supply 1 output by the power module; the power output end of the DC-DC step-down circuit is connected to one power input end of the processor; the other end of the capacitor is connected to the power input end of the DC-DC boost circuit, and the power output end of the DC-DC boost circuit is connected to another power input end of the processor; the comparator communicates signals with the DC-DC boost circuit and transmits signals to the processor; the processor is connected to an emergency brake button; The deceleration brake module includes relay 1 and relay 2; one end of electromagnetic coil 2 is connected to a contact of relay 1 and relay 2, and the other end is connected to electromagnetic coil 1 and one end of AC power supply; the other end of electromagnetic coil 1 is connected to another contact of relay 1, another contact of relay 2 and the other end of AC power supply; both ends of electromagnetic coil 3 of relay 1 and relay 2 are connected to the processor; When the AC power supply is normally energized to electromagnetic coil one, the rotor rotates normally; however, when encountering a sudden power outage, the power outage detection module can quickly identify the power outage and promptly connect relay one of the deceleration brake module, so that electromagnetic coil one, relay one and electromagnetic coil two form a closed-loop circuit, and use the electrical energy generated by the rotor's rotation after power failure to maintain electromagnetic coil one to continue to generate an electromagnetic field. At the same time, electromagnetic coil two generates an electromagnetic field to make the upper friction disc and the lower friction disc frictionally contact, thereby achieving the effect of rapid braking and power-off protection.

2. The operating method of a high-load magnetic levitation pump with an emergency stop and power-off protection device according to claim 1, characterized in that: The method is as follows: (1) When the AC power supply is energized to electromagnetic coil 1, the rotor rotates; the voltage of the fully charged capacitor is lower than the system voltage, and the system voltage passes through the DC-DC step-down circuit to provide the voltage required by the processor; the comparator compares the system voltage and the voltage of the capacitor and outputs a high-level signal; at this time, the DC-DC boost circuit receives the high-level signal of the comparator and cannot play a boosting role, and the processor does not use the voltage provided by the capacitor; the processor receives the high-level signal of the comparator and does not start the brake shutdown. At this time, the processor outputs a low-level signal to relay 1 and relay 2, and relay 1 and relay 2 are both in the disconnected state. Electromagnetic coil 2 is not energized, and the upper friction plate and the lower friction plate are in the separated state. (2) When the AC power supply to electromagnetic coil 1 is suddenly cut off, the system voltage is lower than the voltage of the capacitor. After the comparator compares the system voltage with the voltage of the capacitor, it outputs a low-level signal; the DC-DC boost circuit receives the low-level signal from the comparator, achieves a boosting effect, and provides power to the processor after the electromagnetic coil 1 is powered off; after the processor receives the low-level signal from the comparator, it starts the parking brake and outputs a high-level signal to relay 1. After receiving the high-level signal, relay 1 is connected, and electromagnetic coil 1, relay 1 and electromagnetic coil 2 form a closed-loop circuit. After the electromagnetic coil 1 is powered off, the current generated by the rotor that is still rotating is connected to electromagnetic coil 2 through relay 1; at this time, electromagnetic coil 2 generates an axial electromagnetic field, causing the upper friction disk in the electromagnetic field to rub against the lower friction disk, which plays a role in decelerating the rotor and completing the rotor stop before the power of capacitor 1 is exhausted.

3. The operating method of a high-load magnetic levitation pump with an emergency stop and power-off protection device according to claim 2, characterized in that: When an accident occurs, the emergency brake button is manually triggered. After the processor receives the high-level signal from the emergency brake button, it starts the parking brake and outputs a high-level signal to relay 2. Relay 2 connects the AC power supply and electromagnetic coil 2. At this time, the voltage input from the AC power supply to the electromagnetic coil 2 is the rated voltage, and the friction force between the upper friction plate and the lower friction plate reaches the maximum state, realizing the effect of rotor braking.

4. The operating method of a high-load magnetic levitation pump with an emergency stop and power-off protection device according to claim 2, characterized in that: At the initial moment when the AC power supply is cut off to the electromagnetic coil 1, the rotor rotates at the highest speed, the corresponding current input to the electromagnetic coil 2 is the highest, and the braking capacity of the upper friction plate and the lower friction plate is the strongest.

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