Surge protection method for magnetic suspension blower

Abstract

The invention provides a surge protection method for a magnetic suspension blower, and belongs to the technical field of blowers, and the surge protection method for the magnetic suspension blower comprises the following steps: measuring the outlet pressure of the magnetic suspension blower in real time; when the outlet pressure is smaller than or equal to the surge protection threshold value, the magnetic suspension blower operates normally; when the outlet pressure is larger than the surge protection threshold value, timing is started, and the duration t when the outlet pressure is larger than the surge protection threshold value is obtained; when the duration t is smaller than a first preset value, the magnetic suspension air blower operates normally; and when the duration t is larger than or equal to the first preset value, surge protection is triggered, and the magnetic suspension air blower is shut down. According to the surge protection method for the magnetic suspension air blower, non-surge overpressure conditions such as load sudden change and pipeline instantaneous fluctuation can be effectively filtered, the false triggering probability of surge protection is greatly reduced, and the operation continuity of the air blower and the stability of field production are guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of blower technology, specifically relating to a surge protection method for a magnetic levitation blower. Background Technology

[0002] When the blower in a magnetic levitation blower is operating normally, air blows forward and maintains a stable output. During surge, if the outlet pressure is too high and the air volume is too large, the airflow cannot enter and will flow back. At this time, the blower will vibrate violently, whistle, and the pressure will fluctuate wildly. In severe cases of surge, the magnetic levitation bearing will be damaged, and the impeller, pipes, and flanges will be damaged, leading to direct shutdown or even scrapping.

[0003] Magnetic levitation blowers are generally equipped with surge protection. When the outlet pressure exceeds the surge pressure protection threshold, the blower automatically shuts down to prevent blower vibration caused by blockage of the air supply on the outlet side or excessive resistance. During the process of a magnetic levitation blower supplying air into the air duct, sudden changes in user load can cause a rapid increase or fluctuation in the blower's outlet pressure, which can easily trigger the surge protection shutdown, resulting in production stoppage. Summary of the Invention

[0004] This invention provides a surge protection method for magnetic levitation blowers, aiming to solve the technical problem that existing magnetic levitation blowers are prone to triggering surge protection, causing production stoppages on site.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a surge protection method for a magnetic levitation blower, comprising: Real-time measurement of the outlet pressure of the magnetic levitation blower; When the outlet pressure is less than or equal to the surge protection threshold, the magnetic levitation blower operates normally; when the outlet pressure is greater than the surge protection threshold, timing begins to obtain the duration t of the outlet pressure being greater than the surge protection threshold. When the duration t is less than the first preset value, the magnetic levitation blower operates normally; when the duration t is greater than or equal to the first preset value, surge protection is triggered, and the magnetic levitation blower stops.

[0006] In one possible implementation, after the surge protection is triggered and the magnetic levitation blower stops, the magnetic levitation blower is restarted after waiting for a first preset time. Each time the magnetic levitation blower is restarted due to surge protection, the surge protection threshold is adjusted, with each adjustment increment being a fixed value.

[0007] In one possible implementation, the adjustment increment is 1 to 2 kPa.

[0008] In one possible implementation, the vent valve opens each time the magnetic levitation blower is started; and the vent valve closes when the speed of the magnetic levitation blower exceeds a second preset value. Each time the magnetic levitation blower is restarted due to surge protection, the second preset value is increased by the same amount.

[0009] In one possible implementation, after a power outage and reset, both the surge protection threshold and the second preset value are restored to their initial values.

[0010] In one possible implementation, the characteristic is that, during the surge protection process after the magnetic levitation blower is restarted due to surge protection, the outlet pressure of the magnetic levitation blower is acquired in real time, and the difference d between the outlet pressure and the surge protection threshold is calculated. When the difference d is less than the third preset value, the operating speed of the magnetic levitation blower is increased to increase the outlet pressure and avoid surge protection.

[0011] In one possible implementation, if the outlet pressure of the magnetic levitation blower exceeds the surge protection threshold for a duration greater than or equal to a first preset value after the blower increases its speed, the fault is locked, and manual reset is required to restart the magnetic levitation blower.

[0012] In one possible implementation, the magnetic levitation blower controls the actual operating speed to a set value and continues for a second preset duration each time it is first started. The operating speed was then adjusted to the target value, which is less than the set value.

[0013] In one possible implementation, a pressure sensor is installed at the outlet of the magnetic levitation blower, and the magnetic levitation blower also includes a controller configured to: The system acquires real-time data from the pressure sensor and controls the magnetic levitation blower to shut down when the pressure value exceeds the surge protection threshold and the duration exceeds the first preset value.

[0014] The solution described in this application, compared with the prior art, has two conditions for triggering surge protection: first, the outlet pressure exceeds the surge protection threshold; second, the duration of exceeding the surge protection threshold is greater than or equal to a first preset value. Surge protection is only triggered when both conditions are met simultaneously, causing the magnetic levitation blower to shut down. This judgment criterion effectively filters out non-surge-related overpressure situations such as sudden load changes and instantaneous pipeline fluctuations, significantly reducing the probability of false triggering of surge protection and ensuring the continuity of blower operation and the stability of on-site production. By collecting outlet pressure in real time, abnormal changes in blower outlet pressure can be captured immediately. Combined with the cumulative monitoring of overpressure duration, shutdown protection is quickly triggered after confirming the formation of surge risk, achieving accurate identification and timely intervention of surge. This avoids severe blower vibration caused by continuous surge, prevents equipment damage and scrapping due to surge, and extends the service life of the magnetic levitation blower. This method redefines the surge protection triggering conditions without adding complex hardware, resulting in low modification costs and easy implementation. Detailed Implementation

[0015] To make the technical problems, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] The surge protection method for magnetic levitation blowers provided by this invention will now be described.

[0017] The surge protection method for the magnetic levitation blower includes: Real-time measurement of the outlet pressure of the magnetic levitation blower; When the outlet pressure is less than or equal to the surge protection threshold, the magnetic levitation blower operates normally; when the outlet pressure is greater than the surge protection threshold, timing begins to obtain the duration t of the outlet pressure being greater than the surge protection threshold. When the duration t is less than the first preset value, the magnetic levitation blower operates normally; when the duration t is greater than or equal to the first preset value, surge protection is triggered, and the magnetic levitation blower stops.

[0018] It should be noted that the outlet pressure can be measured directly by installing a pressure sensor in the outlet pipe of the magnetic levitation blower, or by converting it using the motor speed. The conversion method requires pre-calibrating the correlation curve between speed, current, and outlet pressure in the controller. Then, the real-time speed and operating current of the motor are collected and substituted into the curve to calculate the real-time value of the outlet pressure.

[0019] Optional, the first preset value is 2s.

[0020] The surge protection method for magnetic levitation blowers provided in this embodiment, compared with the prior art, has two conditions for triggering surge protection: first, the outlet pressure exceeds the surge protection threshold; second, the duration of exceeding the surge protection threshold is greater than or equal to a first preset value. Surge protection will only be triggered, causing the magnetic levitation blower to shut down, when both conditions are met simultaneously. This judgment criterion can effectively filter out non-surge-related overpressure situations such as sudden load changes and instantaneous pipeline fluctuations, significantly reducing the probability of false triggering of surge protection and ensuring the continuity of blower operation and the stability of on-site production.

[0021] By collecting the outlet pressure in real time, abnormal changes in the blower outlet pressure can be captured immediately. Combined with the cumulative monitoring of overpressure duration, the shutdown protection can be quickly triggered after the surge risk is confirmed. This achieves accurate identification and timely intervention of surge, avoids severe vibration of the blower caused by continuous surge, prevents equipment damage and scrapping due to surge, and extends the service life of the magnetic levitation blower.

[0022] This method redefines the conditions for triggering surge protection without requiring complex hardware, resulting in low modification costs and easy implementation.

[0023] In practical implementation, a controller can also be set up to match the magnetic levitation blower. The controller is electrically connected to the magnetic levitation blower and is configured as follows: The system acquires real-time data from the pressure sensor and controls the magnetic levitation blower to shut down when the pressure value exceeds the surge protection threshold and the duration exceeds the first preset value.

[0024] The controller automatically shuts down the magnetic levitation blower and can be linked to pressure sensors to quickly execute corresponding operations when conditions are met. From pressure acquisition to sending the shutdown command, no manual intervention is required, achieving automated and intelligent surge protection. This reduces the workload of operators and avoids the problem of untimely surge protection caused by delayed or erroneous manual judgment, thus improving the automation level and safety protection level of the magnetic levitation blower operation.

[0025] In some embodiments, after the surge protection is triggered and the magnetic levitation blower stops, the magnetic levitation blower is restarted after waiting for a first preset time. Each time the magnetic levitation blower is restarted due to surge protection, the surge protection threshold is adjusted, and the adjustment increment is a fixed value each time.

[0026] For example, when a magnetic levitation blower is initially running, the surge protection threshold is x. After the blower stops due to the first surge protection trigger, the surge protection threshold is adjusted to (x+d) upon restarting. After the blower stops due to the second surge protection trigger, the surge protection threshold is adjusted to (x+2d) upon restarting. And so on.

[0027] Optionally, the adjustment amount is 1 to 2 kPa. That is, the value of d above is 1 to 2 kPa. The first preset duration is 2 minutes.

[0028] After the magnetic levitation blower triggers surge protection and shuts down, it waits for a first preset time. This process ensures that the magnetic levitation bearing is fully stabilized, the impeller stops its inertial rotation, and the pipeline pressure drops back to a safe range. This process avoids blind restarting, eliminates the risk of secondary impact from immediate restarting after surge, and improves the safety of restarting operations.

[0029] After the magnetic levitation blower restarts, the surge protection threshold is increased by a fixed increment to adapt the threshold to changes in actual air supply conditions such as increased load and rising pipe resistance, reducing repeated triggering of surge protection due to dynamic changes in operating conditions. Furthermore, the surge protection threshold is adjusted after a safe restart to avoid ineffective parameter adjustments under unstable equipment conditions.

[0030] When the magnetic levitation blower is restarted by the controller, once the surge protection of the magnetic levitation blower is triggered and the blower stops, the controller can also automatically start the timing module, so that the magnetic levitation blower will automatically start when the first preset time is reached.

[0031] Furthermore, the controller can also be integrated with an alarm to control the magnetic levitation blower. If abnormal levitation of the magnetic levitation bearing or abnormal fluctuation of impeller speed is detected during the restart process, the alarm will sound an audible and visual alarm, and the controller will terminate the restart operation. The blower will restart only after manual troubleshooting and resolution of the fault.

[0032] In some embodiments, the vent valve opens each time the magnetic levitation blower is started; the vent valve closes when the operating speed of the magnetic levitation blower exceeds a second preset value; and the second preset value is increased by the same amount each time the magnetic levitation blower is restarted due to surge protection.

[0033] It should be noted that the mechanical check valve is closed before the blower starts. After the blower starts and its operating speed is lower than the second preset value, the system (same as the controller) controls the vent valve to open, and the blower delivers air through the vent valve to the outside of the equipment, preventing blower surge when the check valve is closed. At this time, the check valve is closed and no air is being supplied to the pipeline. When the blower reaches the second preset value, the system controls the vent valve to close rapidly. At this time, the pressure in the pipeline on the blower outlet side rises sharply. When the pressure exceeds the spring pressure of the mechanical check valve, the check valve opens instantaneously, and gas is continuously supplied to the pipeline.

[0034] During this process, the exhaust valve remains open when the magnetic levitation blower is running normally, which can adjust the airflow pressure of the outlet pipe in real time, avoid small-scale overpressure caused by local pressure accumulation, thereby reducing non-surge pressure fluctuations and providing a stable foundation for the blower's stable air delivery. At the same time, in conjunction with the blower's airflow output characteristics, the adjustment of air pressure is more flexible.

[0035] The blower triggering surge protection essentially indicates a change in the on-site air supply conditions. The original triggering and closing conditions of the vent valve (reaching the second preset value) are no longer suitable for the air pressure regulation requirements of the new conditions. By restarting and increasing the second preset value by the same amount, the opening threshold of the vent valve is effectively raised, allowing the vent valve to remain open for a longer period under the new conditions, enabling more thorough pressure regulation and preventing frequent opening and closing of the vent valve due to changes in operating conditions, thus improving the stability of air pressure regulation.

[0036] The fixed increment of the surge protection threshold is increased simultaneously with the equal increase of the second preset value of the speed, so that the passive surge protection of the blower and the active pressure regulation are linked. That is, by increasing the protection threshold, the probability of surge protection being triggered is reduced, and by increasing the vent valve opening threshold, the active air pressure regulation capability is enhanced. The two work together to change the pressure of the field conditions, thereby improving the blower's adaptability to various working conditions.

[0037] Furthermore, the controller can not only be used to control the shutdown of the blower, but can also be configured to: acquire the operating speed of the magnetic levitation blower and send adjustment commands to the vent valve.

[0038] The controller can directly acquire the real-time speed of the magnetic levitation blower and send adjustment commands to the vent valve. The initial value and variation pattern of the second preset value are also pre-input into the controller, enabling automated and intelligent speed control. Through precise speed regulation, uncontrolled pressure accumulation can be avoided, significantly reducing the probability of false triggering of surge protection.

[0039] The controller simultaneously monitors the blower's outlet pressure and speed data, and can adjust the speed regulation strategy of the magnetic levitation blower in real time according to pressure changes. During operation, the controller can also record the acquired data and execution status, facilitating subsequent review and verification by staff. When production demands change, the triggering conditions and execution paths can be readjusted through analysis of the recorded data and execution status.

[0040] In some embodiments, after a power outage and reset, both the surge protection threshold and the second preset value are restored to their initial values.

[0041] It is important to emphasize that when the blower stops due to surge protection, the surge protection threshold and the second preset value need to be increased after restarting. However, if the blower stops due to a power outage, the surge protection threshold and the second preset value need to be restored to their initial values ​​after restarting.

[0042] Without a power-off reset to restore initial values, the surge protection threshold and the second preset value of the rotational speed will be infinitely increased due to multiple restarts, resulting in accumulated parameter deviations. An excessively high threshold can cause the fan to experience surge but fail to trigger protection, leading to damage to equipment components. The parameter reset after a power-off avoids this type of deviation problem, ensuring that the two parameters can always cyclically adapt to changes in operating conditions, guaranteeing the accuracy of surge protection.

[0043] When the blower is powered off and reset, both parameters automatically return to their initial values ​​without the need for manual adjustment. This allows the blower to directly adapt to basic operating conditions and avoids problems such as pressure regulation failure and abnormal blower air pressure output caused by the adjusted parameters.

[0044] During on-site maintenance, if the adjusted dual parameters need to be restored to their initial values ​​after equipment shutdown for repair or change of operating conditions, manual calculation and adjustment are not only time-consuming and labor-intensive, but also prone to human error. This embodiment achieves automatic synchronous reset of dual parameters, eliminating the need for manual intervention by maintenance personnel to adjust parameters. This significantly simplifies the parameter restoration process after equipment shutdown, repair, or change of operating conditions, and reduces the workload of maintenance personnel.

[0045] In some embodiments, the characteristic is that, after the surge protection restarts the magnetic levitation blower, during the continued surge protection process, the outlet pressure of the magnetic levitation blower is acquired in real time, and the difference d between the outlet pressure and the surge protection threshold is calculated; when the difference d is less than a third preset value, the operating speed of the magnetic levitation blower is increased to increase the outlet pressure and avoid surge protection.

[0046] Optionally, the third preset value is 0.5 kPa.

[0047] After a blower restarts due to surge protection, if the outlet pressure continues to approach the surge protection threshold (the difference d is less than the third preset value), the conditions for triggering a shutdown are not met, but it is a typical surge critical state. This method calculates the difference d in real time and determines the critical state, promptly increasing the blower's operating speed to proactively adjust the outlet pressure from the source, pulling the pressure away from the surge critical range. This achieves early prediction and proactive intervention of surge risk, significantly reducing the probability of erroneously triggering a surge shutdown again after restarting.

[0048] If the outlet pressure of the blower continues to fluctuate around the surge protection threshold after restarting, it is highly likely that even a small pressure fluctuation will meet the triggering conditions and trigger another shutdown. Such meaningless repeated shutdowns will cause equipment operation interruptions and production stoppages. This method quickly avoids the surge protection triggering conditions by increasing the operating speed of the magnetic levitation blower, mitigating the risk of critical surge without interrupting equipment operation. This effectively ensures the continuous operation of the magnetic levitation blower after restarting, avoids unnecessary interruptions in the production process, and improves the stability of on-site production.

[0049] In some embodiments, if the outlet pressure of the magnetic levitation blower exceeds the surge protection threshold for a duration greater than or equal to a first preset value after the speed of the magnetic levitation blower is increased, the fault is locked and manual reset is required to restart the magnetic levitation blower.

[0050] If the outlet pressure still exceeds the threshold and persists for a long time after the operating speed of the magnetic levitation blower is increased, it indicates that the surge is a persistent and high-risk fault, triggering a fault lockout. This tiered design makes surge protection more targeted, avoiding excessive lockout protection for minor surge risks that can be mitigated, and also eliminating the perfunctory treatment of simply shutting down the machine for persistent and high-risk surge.

[0051] The fault lockout design ensures that the blower enters a locked state that cannot be automatically restarted after it stops. It can only be unlocked by manual intervention, which completely avoids blind restarting without troubleshooting the fault, minimizes the risk of secondary equipment damage after surge, and protects the core hardware of the magnetic levitation blower.

[0052] In some embodiments, each time the magnetic levitation blower is started for the first time, the actual operating speed is controlled to a set value and maintained for a second preset duration; then the operating speed is adjusted to a target value, which is less than the set value.

[0053] When a magnetic levitation blower is started for the first time, if it is run directly at a low target speed, problems such as slow pressure build-up, uneven airflow velocity in the pipeline, and large pressure fluctuations may occur. Insufficient pressure may even lead to poor airflow delivery. Running it at a higher set speed for a second preset duration can quickly improve the blower's efficiency, establish a stable and sufficient initial air pressure in the outlet pipeline in a short time, and allow the airflow in the pipeline to quickly reach a uniform delivery state. This avoids insufficient air pressure and airflow turbulence in the initial startup phase, ensuring that the air supply system is in a stable airflow delivery state from the startup stage.

[0054] Short-term operation at high set speeds allows the magnetic levitation bearing to quickly enter a stable levitation state, and the impeller to quickly reach a stable rotation state. This avoids the initial mechanical wear caused by insufficient bearing levitation and impeller wobbling during low-speed startup. At the same time, it allows the core components to complete startup adaptation at high speeds for a short period, laying a good mechanical foundation for subsequent stable low-speed operation and extending the service life of the core components.

[0055] As one specific embodiment of this application, an example is given below: Surge protection pressure threshold, with a given 2s filtering time (system default 2s, can be modified via the human-machine interface). That is, when the real-time outlet pressure (in kPa) continuously exceeds the surge protection pressure threshold (in kPa) for more than 2 seconds, surge protection shutdown is triggered. If the real-time outlet pressure continuously exceeds the surge protection pressure threshold for more than 2 seconds, the machine will shut down due to a fault. After a 2-minute delay (to ensure the magnetic levitation system can safely settle), the machine will automatically restart and increase the surge protection threshold by 1 kPa (after a power-off reset, the surge protection threshold will return to its original value). After the blower restarts automatically, the blower speed corresponding to when the vent valve is closed is increased (after power failure and reset, the blower speed corresponding to when the vent valve is closed returns to its original value, and the blower operating speed corresponding to when the vent valve is closed is the second preset value mentioned above), to ensure that the outlet pressure at the moment the check valve is opened is greater than the backflow pressure in the pipeline, thus avoiding triggering surge protection. If the system continues to approach surge protection (i.e., the surge protection pressure threshold - real-time outlet pressure < 0.5 kPa is met), the operating speed of the magnetic levitation blower will be actively increased to raise the outlet pressure and avoid surge protection. After adjustment, if the real-time outlet pressure exceeds the surge protection pressure threshold and remains there for more than 2 seconds, the surge protection will be triggered, the blower will shut down, and the fault will be locked. It can only be restarted after manual reset. Each time the system is started for the first time, it controls the actual operating speed to run at the target speed (in rpm) +1000 rpm for 10 seconds, actively increasing the outlet pressure to avoid the surge protection point as much as possible; after 10 seconds, the actual operating speed is restored to the target speed.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A surge protection method for a magnetic levitation blower, characterized in that, include: Real-time measurement of the outlet pressure of the magnetic levitation blower; The magnetic levitation blower operates normally when the outlet pressure is less than or equal to the surge protection threshold. When the outlet pressure exceeds the surge protection threshold, start timing to obtain the duration t of the outlet pressure exceeding the surge protection threshold; When the duration t is less than the first preset value, the magnetic levitation blower operates normally; when the duration t is greater than or equal to the first preset value, surge protection is triggered, and the magnetic levitation blower stops.

2. The surge protection method for a magnetic levitation blower as described in claim 1, characterized in that, After the surge protection is triggered and the magnetic levitation blower stops, wait for the first preset time and then restart the magnetic levitation blower. Each time the magnetic levitation blower is restarted due to surge protection, the surge protection threshold is adjusted, with each adjustment increment being a fixed value.

3. The surge protection method for a magnetic levitation blower as described in claim 2, characterized in that, Adjust the increment to 1-2 kPa.

4. The surge protection method for a magnetic levitation blower as described in claim 2, characterized in that, The vent valve opens each time the magnetic levitation blower is started; the vent valve closes when the operating speed of the magnetic levitation blower exceeds the second preset value. Each time the magnetic levitation blower is restarted due to surge protection, the second preset value is increased by the same amount.

5. The surge protection method for a magnetic levitation blower as described in claim 4, characterized in that, After power is cut off and reset, both the surge protection threshold and the second preset value return to their initial values.

6. The surge protection method for a magnetic levitation blower as described in any one of claims 2-5, characterized in that, After the surge protection restarts the magnetic levitation blower, during the surge protection process, the outlet pressure of the magnetic levitation blower is acquired in real time, and the difference d between the outlet pressure and the surge protection threshold is calculated. When the difference d is less than the third preset value, the operating speed of the magnetic levitation blower is increased to increase the outlet pressure and avoid surge protection.

7. The surge protection method for a magnetic levitation blower as described in claim 6, characterized in that, If the outlet pressure of the magnetic levitation blower exceeds the surge protection threshold for a duration greater than or equal to the first preset value after the speed of the magnetic levitation blower is increased, the fault will be locked and manual reset is required to restart the magnetic levitation blower.

8. The surge protection method for a magnetic levitation blower as described in claim 1, characterized in that, Each time the magnetic levitation blower is started for the first time, the actual operating speed is controlled to the set value and continues for a second preset duration. The operating speed was then adjusted to the target value, which is less than the set value.

9. The surge protection method for a magnetic levitation blower as described in claim 1, characterized in that, A pressure sensor is installed at the outlet of the magnetic levitation blower. The magnetic levitation blower also includes a controller, which is configured to: The system acquires real-time data from the pressure sensor and controls the magnetic levitation blower to shut down when the pressure value exceeds the surge protection threshold and the duration exceeds the first preset value.