Fan and method and device for detecting foreign matters in fan

Abstract

A fan and a method and device for detecting foreign matters in the fan are provided, a plurality of ultrasonic sensors are annularly arranged on a hub in the fan at equal angles, the detection method comprises the following steps: setting a target rotating speed for the fan before the fan runs, calculating the actual rotating speed of the fan by acquiring a feedback signal of the fan, and calculating the rotating speed of the fan according to the actual rotating speed; when the absolute value of the difference value between the target rotating speed and the actual rotating speed exceeds the speed difference threshold value, it is judged that foreign matter exists in the fan, and otherwise, it is judged that no foreign matter exists in the fan; when the fan runs, the measurement distance of ultrasonic waves of each ultrasonic sensor from transmitting to receiving is calculated, when the measurement distances corresponding to the three adjacent ultrasonic sensors in one sampling period are smaller than or equal to an abnormal distance threshold value, it is judged that foreign matter exists in the fan, and otherwise, it is judged that no foreign matter exists in the fan; the invention provides a method for detecting foreign matters before operation of the fan and detecting the foreign matters during operation, so that the stability of the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of foreign matter detection in fans, and in particular to a method and device for detecting foreign matter in a fan and inside the fan. Background Art

[0002] Fans are widely used in ventilation, air conditioning, industrial production, and other fields. They are essential equipment in modern industry and construction. With technological advancements, the performance, efficiency, and intelligence of fan equipment are constantly improving, providing important support for the sustainable development of various industries.

[0003] Before a fan is started, the presence of foreign matter inside it can damage key components like the impeller, bearings, and casing. It can also lead to serious consequences such as motor overload, airflow obstruction, and control system failure. These consequences not only affect the fan's performance and efficiency but can also cause serious damage to the equipment, disrupting normal production. Therefore, a pre-startup inspection of the fan is crucial to ensure that the interior is clean and free of foreign matter to ensure proper operation and extend the life of the equipment.

[0004] Currently, traditional wind turbine foreign object detection relies on manual visual inspection or camera monitoring, which has problems such as low efficiency, many blind spots, and susceptibility to interference from ambient light or dust. Summary of the Invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a method and device for detecting foreign matter in a fan and a fan.

[0006] The present invention adopts the following technical solutions:

[0007] A first aspect of the present application provides a method for detecting foreign matter inside a fan, wherein a plurality of ultrasonic sensors are arranged in a ring at equal angles on the internal hub of the fan, and the detection method comprises the following steps:

[0008] Before the fan is running, a target speed is set for the fan. The actual speed of the fan is calculated by obtaining the feedback signal of the fan. When the absolute value of the difference between the target speed and the actual speed exceeds the speed difference threshold, it is determined that there is a foreign object inside the fan. Otherwise, there is no foreign object inside the fan.

[0009] When the fan is running, the measured distance from the emission to the reception of the ultrasonic wave of each ultrasonic sensor is calculated. If the corresponding measured distances of three adjacent ultrasonic sensors within a sampling period are less than or equal to the abnormal distance threshold, it is determined that there is a foreign object inside the fan. Otherwise, it is determined that there is no foreign object inside the fan.

[0010] According to the method for detecting foreign matter inside a wind turbine, the abnormal distance threshold is set according to a standard distance, and the standard distance is obtained from a standard distance database or calculated when the wind turbine is first put into use.

[0011] According to the method for detecting foreign matter inside a fan, when the fan is running, calculating the measured distance from the time when the ultrasonic wave is emitted to the time when it is received specifically includes:

[0012] Get the initial position x0 and initial time t0 when the ultrasonic wave is emitted, the time t when the ultrasonic wave returns to the receiver, and the velocity function v(t ′ );

[0013] And calculate the measured distance from ultrasonic emission to reception according to the following formula:

[0014]

[0015] Wherein, di(t) represents the measurement distance corresponding to the i-th ultrasonic sensor.

[0016] According to the method for detecting foreign matter inside a fan, the actual speed of the fan is calculated by obtaining a feedback signal from the fan, which specifically includes:

[0017] Get the number of pulses corresponding to the unit speed of the fan;

[0018] Collect the total number of pulses in the set time period;

[0019] The actual speed is obtained by the ratio of the total number of pulses to the number of pulses corresponding to the unit speed and the set time period.

[0020] According to the method for detecting foreign matter inside a fan, when it is determined that a foreign matter exists inside the fan, an alarm is sent to a control center, and the fan shutdown system is linked to shut down the fan.

[0021] In a second aspect of the present application, a device for detecting foreign matter inside a fan is provided, for performing the above-mentioned detection method, the device comprising:

[0022] A signal processing module, used to modulate the frequency of the ultrasonic wave within a preset range;

[0023] The pre-operation foreign body judgment module is used to set a target speed for the fan before the fan is operated. By obtaining the fan's feedback signal, the actual speed of the fan is calculated. When the absolute value of the difference between the target speed and the actual speed exceeds the speed difference threshold, it is determined that there is a foreign body inside the fan. Otherwise, there is no foreign body inside the fan.

[0024] The runtime foreign object judgment module is used to calculate the measurement distance of each ultrasonic sensor from the time of ultrasonic emission to reception when the fan is running; when the corresponding measurement distances of three adjacent ultrasonic sensors within a sampling period are less than or equal to the abnormal distance threshold, it is determined that there is a foreign object inside the fan; otherwise, it is determined that there is no foreign object inside the fan.

[0025] According to the device for detecting foreign matter inside a fan, the device further includes:

[0026] The alarm and linkage module is used to send an alarm to the control center and link the fan shutdown system to shut down the fan when it is determined that there is foreign matter inside the fan.

[0027] A third aspect of the present application provides a wind turbine comprising the above-mentioned detection device.

[0028] In a fourth aspect of the present application, a storage medium is provided, wherein the storage medium includes a stored program, wherein when the program is run, the device where the storage medium is located is controlled to execute the method for detecting foreign matter inside a fan.

[0029] Compared with the prior art, the beneficial effects of the present invention include at least:

[0030] 1. The present invention provides a method for detecting foreign objects inside a fan. Before the fan is operated, the presence of large foreign objects is determined by comparing a preset target speed with the actual measured target speed, thereby avoiding more serious malfunctions. During fan operation, the presence of foreign objects is determined by comparing the distance from ultrasonic emission to return reception with an abnormal distance threshold. Furthermore, the presence of foreign objects is determined by comparing the corresponding measured distances of three adjacent ultrasonic sensors within a sampling period with the abnormal distance threshold. This eliminates erroneous determinations caused by false alarms from a single ultrasonic sensor, improving system stability. Furthermore, when a foreign object is determined to be present, an alarm is immediately sent to the control center, and the fan shutdown system is activated to prevent further damage.

[0031] 2. The ultrasonic sensor array of the present invention is arranged in an equiangular ring inside the fan to form a detection network without blind spots, solving the blind spot problem of traditional solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0033] Figure 1 is a flow chart of the detection method of the present invention;

[0034] Figure 2 This is a three-dimensional structural diagram of the fan of the present invention;

[0035] Figure 3 This is a back view of the fan of the present invention;

[0036] Figure 4 It is a side view of the wheel hub of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0038] Unless specifically stated otherwise, the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure.

[0039] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0040] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0041] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0042] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0043] Ultrasonic technology has the advantages of being non-contact, highly anti-interference, and adaptable to complex environments.

[0044] like Figure 1 As shown, embodiment 1 of the present invention provides a method for detecting foreign matter inside a fan, wherein a plurality of ultrasonic sensors are arranged in a ring at equal angles on the internal hub of the fan;

[0045] The ultrasonic sensor includes an ultrasonic transmitting module and a receiving module, for example Figure 3 or Figure 4 As shown, nine sets of ultrasonic transmitting modules and receiving modules are installed on the nine hubs of the wind turbine to form a detection network covering the wind turbine area. At the same time, the coverage range of the ultrasonic sensor beam is increased, or an ultrasonic sensor with a large beam coverage range is selected to improve the detection accuracy.

[0046] In another embodiment, the ultrasonic sensor is mounted on the hub and is located on the hub near the junction of the wind turbine hub, the inner wall of the nacelle and the root of the blade.

[0047] Before leaving the factory, calculate d0 for each model of fan using the integral equation in step 1 below to obtain the standard distance between the ultrasonic sensor and the inner wall of the fan facing it when there is no foreign matter in the factory. Figure 3 As shown, a standard distance database is generated.

[0048] The detection method comprises the following steps:

[0049] Step 1: When the fan is running, calculate the measured distance from the time the ultrasonic wave of each ultrasonic sensor is transmitted to the time it is received, specifically including:

[0050] Get the initial position x0 and initial time t0 when the ultrasonic wave is emitted, the time t when the ultrasonic wave returns to the receiver, and the velocity function v(t ′ );

[0051] And calculate the measured distance from ultrasonic emission to reception according to the following formula:

[0052]

[0053] Wherein, di(t) represents the measured distance from the time of emission to reception of the ultrasonic wave corresponding to the i-th ultrasonic sensor.

[0054] Under normal circumstances, the speed of ultrasound is constant. Under complex working conditions and / or when high precision is required, the speed change of ultrasound is collected in real time and a speed function is generated to accurately calculate the distance from the ultrasound emission to the return reception.

[0055] Under normal circumstances, when d0 is measured before leaving the factory, the position of the ultrasonic sensor remains unchanged relative to when it is in use, so x0 is 0. However, when the ultrasonic sensor fails, it is repaired or replaced, resulting in a change in its relative position. In this case, re-testing is required. At this time, the difference between d0 and d0' is x0, relative to d0' when the ultrasonic sensor is free of foreign matter.

[0056] The abnormal distance threshold D is set according to the standard distance d0, which is obtained from a standard distance database or calculated when the wind turbine is first put into use. D=k*d0, where the value range of k is [1.8-1.9].

[0057] When the fan is first put into use, the measurement distances corresponding to all ultrasonic sensors inside the fan of this fan model are calculated using the formula in step 1 above. Each ultrasonic sensor calculates the measurement distance at least once. The value obtained by weighted average of all measurement distances is the standard distance d0.

[0058] Step 2: When the corresponding measurement distances of three adjacent ultrasonic sensors within a sampling period are less than or equal to the abnormal distance threshold, it is determined that there is a foreign object inside the fan, an alarm is sent, and the fan is shut down to prevent further damage. Otherwise, it is determined that there is no foreign object inside the fan;

[0059] The present invention eliminates erroneous judgments caused by false alarms from a single ultrasonic sensor by simultaneously acquiring the measurement distances corresponding to adjacent ultrasonic sensors, thereby improving the stability of the system.

[0060] Embodiment 2 of the present invention provides a method for detecting foreign matter inside a fan, comprising the following steps:

[0061] Set a target speed for the fan and calculate the actual speed of the fan by obtaining the feedback signal from the fan. When the absolute value of the difference between the target speed and the actual speed exceeds the speed difference threshold ΔV, it is determined that a foreign object is present. Otherwise, no foreign object is present. Specifically, the following are included:

[0062] Get the number of pulses corresponding to the unit speed of the fan;

[0063] Collect the total number of pulses Psum within the set time period ΔT; calculate the actual speed using the following formula:

[0064]

[0065] The above-mentioned target speed is obtained by the ratio of the theoretical total number of pulses to the number of pulses corresponding to the unit speed within the ΔT time period when there is no fault.

[0066] The present invention sets the fan at a very low target speed before starting the fan, with a value range of less than 10% of the rated speed of the fan, and then calculates the actual speed of the fan. When the absolute value of the difference between the target speed and the actual speed exceeds the speed difference threshold ΔV, potential problems such as foreign matter getting stuck can be discovered early, thereby avoiding more serious faults.

[0067] The target speed is set at a very low speed value in order to amplify the tiny foreign object signal of the device by reducing the operating speed, thereby achieving early fault detection.

[0068] In one embodiment, the unit speed of the fan corresponds to 2 cycles of pulses, that is, 1r = 2Pulse, and V0 is set to 3r / s. Then the total number of pulses within 5 seconds should normally be: 3 rpm × 2 pulses / rpm × 5 seconds = 30 pulses, and the speed difference threshold ΔV is set to 1.5r / s;

[0069] The total number of pulses actually collected is 20 pulses. The actual speed calculated by the above formula is 1.33r / s.

[0070] The absolute value of the difference between the target speed and the actual speed is 1.78 r / s. If it exceeds the above speed difference threshold, it is determined that there is a foreign object inside the fan.

[0071] Embodiment 3 of the present invention provides a device for detecting foreign matter inside a fan, comprising:

[0072] A signal processing module, used to modulate the frequency of the ultrasonic wave within a preset range;

[0073] The pre-operation foreign body judgment module is used to set a target speed for the fan before the fan is operated. By obtaining the fan's feedback signal, the actual speed of the fan is calculated. When the absolute value of the difference between the target speed and the actual speed exceeds the speed difference threshold, it is determined that there is a foreign body inside the fan. Otherwise, there is no foreign body inside the fan.

[0074] The runtime foreign object judgment module is used to calculate the measurement distance of each ultrasonic sensor from the time of ultrasonic emission to reception when the fan is running; when the corresponding measurement distances of three adjacent ultrasonic sensors within a sampling period are less than or equal to the abnormal distance threshold, it is determined that there is a foreign object inside the fan; otherwise, it is determined that there is no foreign object inside the fan.

[0075] The alarm and linkage module is used to send an alarm to the control center and link the fan shutdown system to shut down the fan when it is determined that there is foreign matter inside the fan.

[0076] Embodiment 4 of the present invention provides a wind turbine including the above-mentioned detection device.

[0077] Embodiment 5 of the present invention provides a storage medium storing a computer program. When the program is executed by a processor, the method for detecting foreign matter inside a fan disclosed in the present invention is implemented.

[0078] Storage medium can be the tangible device that can keep and store the instruction used by instruction execution device.Storage medium can be, for example, but is not limited to electric storage device, magnetic storage device, optical storage device, electromagnetic storage device, semiconductor storage device or above-mentioned any suitable combination.The more specific example (non-exhaustive list) of storage medium comprises: portable computer disk, hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanical coding device, for example, punch card or the convex structure in the groove that stores instruction thereon and above-mentioned any suitable combination.Storage medium used here is not interpreted as instantaneous signal itself, such as radio wave or other free propagating electromagnetic wave, electromagnetic wave (for example, by the light pulse of fiber optic cable) that waveguide or other transmission medium propagates or the electric signal transmitted by wire.

[0079] The computer-readable program instructions described herein can be downloaded from a storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to the storage medium in each computing / processing device for storage.

[0080] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional procedural programming languages ​​such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., utilizing an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions. The electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for detecting foreign matter inside a fan, characterized in that: Several ultrasonic sensors are arranged in a ring with equal angles on the internal hub of the fan. The detection method includes the following steps: Before the fan is running, a target speed is set for the fan. The actual speed of the fan is calculated by obtaining the feedback signal of the fan. When the absolute value of the difference between the target speed and the actual speed exceeds the speed difference threshold, it is determined that there is a foreign object inside the fan. Otherwise, there is no foreign object inside the fan. When the fan is running, the measured distance from the emission to the reception of the ultrasonic wave of each ultrasonic sensor is calculated. If the corresponding measured distances of three adjacent ultrasonic sensors within a sampling period are less than or equal to the abnormal distance threshold, it is determined that there is a foreign object inside the fan. Otherwise, it is determined that there is no foreign object inside the fan.

2. A method for detecting foreign matter inside a fan according to claim 1, characterized in that: The abnormal distance threshold is set according to a standard distance, and the standard distance is obtained from a standard distance database or calculated when the wind turbine is first put into use.

3. The method for detecting foreign matter inside a fan according to claim 1, wherein: When the fan is running, the measurement distance from the ultrasonic wave emission to the ultrasonic wave reception is calculated, specifically including: Get the initial position x0 and initial time t0 when the ultrasonic wave is emitted, the time t when the ultrasonic wave returns to the receiver, and the velocity function v(t ′ ); And calculate the measured distance from ultrasonic emission to reception according to the following formula: Wherein, di(t) represents the measurement distance corresponding to the i-th ultrasonic sensor.

4. The method for detecting foreign matter inside a fan according to claim 1, wherein: The actual speed of the fan is calculated by obtaining the feedback signal of the fan, specifically including: Get the number of pulses corresponding to the unit speed of the fan; Collect the total number of pulses in the set time period; The actual speed is obtained by the ratio of the total number of pulses to the number of pulses corresponding to the unit speed and the set time period.

5. The method for detecting foreign matter inside a fan according to claim 1, wherein: When it is determined that there is a foreign object inside the fan, an alarm is sent to the control center, and the fan shutdown system is linked to shut down the fan.

6. A device for detecting foreign matter inside a fan, used to perform the method for detecting foreign matter inside a fan according to any one of claims 1 to 5, characterized in that: The device comprises: A signal processing module, used to modulate the frequency of the ultrasonic wave within a preset range; The pre-operation foreign body judgment module is used to set a target speed for the fan before the fan is operated. By obtaining the fan's feedback signal, the actual speed of the fan is calculated. When the absolute value of the difference between the target speed and the actual speed exceeds the speed difference threshold, it is determined that there is a foreign body inside the fan. Otherwise, there is no foreign body inside the fan. The runtime foreign object judgment module is used to calculate the measurement distance of each ultrasonic sensor from the time of ultrasonic emission to reception when the fan is running; when the corresponding measurement distances of three adjacent ultrasonic sensors within a sampling period are less than or equal to the abnormal distance threshold, it is determined that there is a foreign object inside the fan; otherwise, it is determined that there is no foreign object inside the fan.

7. The device for detecting foreign matter inside a fan according to claim 6, characterized in that: Also includes: The alarm and linkage module is used to send an alarm to the control center and link the fan shutdown system to shut down the fan when it is determined that there is foreign matter inside the fan.

8. A fan, characterized in that: include: The detection device according to claim 6 or 7.

9. A storage medium, characterized in that: The storage medium includes a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute the method for detecting foreign matter inside a fan according to any one of claims 1 to 5.

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