Fan state monitoring system and method

Abstract

According to the fan state monitoring system and method, on-off signals formed when fan blades pass through an optical fiber sensor are monitored to serve as pulses to calculate the rotating speed of a fan, and the fan state is accurately judged. In addition, the state of the fan can be judged by measuring the temperature of the air port of the fan. The method can be realized by utilizing field controller resources, does not need to buy hardware repeatedly, and can effectively overcome the defects that in the prior art, a direct-current circuit feedback method is unstable in work and hard to keep stable work in a strong magnetic severe environment; the direct-current circuit feedback cannot calculate the actual fan rotating speed; and the cost at the early stage of circuit development is high.

Description

Technical Field

[0001] The invention belongs to the field of permanent magnetic heaters, and in particular relates to a fan state monitoring system and method. Background Art

[0002] At present, the common fan fault feedback method is the DC circuit detection method, which uses the change in current to judge the fan status by designing a feedback circuit. However, the DC circuit is unstable in a strong magnetic environment and cannot quickly and accurately feedback the fan status, especially the speed. For example, when the motor is stuck and burns, there is current flowing, but the fan is not actually working, resulting in false detection. In addition, there are also defects such as high initial circuit development costs and the inability to repair the circuit and resume industrial production in time when a circuit failure occurs in the later stage.

[0003] This technology uses the cooperation of multiple sensors and industrial controllers to achieve accurate feedback of fan status, so that fans can be repaired in a timely and effective manner upon receiving an alarm. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a fan status monitoring system and method, which can receive fan abnormality signals before an accident occurs and process them in time, thereby accurately and digitally controlling the scene.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A fan status monitoring system, comprising:

[0007] The optical fiber sensor includes an optical fiber transmitting end and an optical fiber receiving end respectively arranged on the front and back sides of the fan to be tested. The optical fiber sensor generates a pulse signal by detecting the rotating fan blades.

[0008] The controller receives the pulse signal, calculates the number of pulses per unit time to obtain the actual fan speed value, and sets the corresponding pulse threshold. When the number of pulses per unit time is lower than the corresponding pulse threshold, an alarm signal is issued.

[0009] The optical fiber sensor also includes an optical fiber amplifier, which amplifies the pulse signal and outputs the amplified pulse signal to the controller.

[0010] The controller comprises a timing interruption organization module for editing and accumulating the received pulse signals.

[0011] The monitoring system also includes a temperature sensor, which is installed at the air outlet of the fan being tested to detect the air temperature at the air outlet and input it into a controller to calculate the actual temperature value in the air. When the measured air temperature suddenly rises and is greater than the set temperature threshold and lasts for a corresponding time, an alarm signal is issued.

[0012] A monitoring method for a fan status monitoring system, comprising the following steps:

[0013] A. Fiber optic transmitting ends and fiber optic receiving ends are respectively arranged on the front and back sides of the fan to be measured. By rotating the fan blades to intermittently cross the emitted light, pulse signals are detected and generated;

[0014] B. The controller receives the pulse signals, calculates the number of pulses within a unit time to obtain the actual fan rotation speed value, and by setting corresponding pulse thresholds, when the number of pulses within a unit time is lower than the corresponding pulse threshold, an alarm signal is issued.

[0015] In step A, a temperature measuring sensor is also arranged at the air outlet of the fan to be measured to detect the air temperature at the air outlet and input it into the controller to calculate the actual temperature value in the air. When the measured air temperature suddenly rises and is greater than the set temperature threshold and lasts for a corresponding time, an alarm signal is also issued.

[0016] By using the fan status monitoring system and method of the present invention, the on-off signal formed by the fan blades passing through the fiber optic sensor is used as a pulse to calculate the rotation speed of the fan, and the fan status is accurately judged. In addition, the fan status can also be judged by measuring the air temperature at the fan air outlet. The present invention can be implemented by using the resources of the on-site controller without the need to repeatedly purchase hardware, and can effectively overcome the defects existing in the prior art, such as the unstable operation of the method of DC circuit feedback, the difficulty in maintaining stable operation in a strong magnetic and harsh environment; the DC circuit feedback cannot calculate the actual fan rotation speed; the pre-development cost of the circuit is relatively high, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an installation schematic diagram of the fan status monitoring system of the present invention

[0018] Figure 2 is a principle block diagram of the fan status monitoring system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] The fan status monitoring system of the present invention is as Figure 1 - Figure 2As shown in the figure, it includes an optical fiber sensor. The optical fiber sensor includes an optical fiber transmitting end 10 and an optical fiber receiving end 20 respectively disposed on the front and back sides of the fan to be measured. The optical fiber transmitting end 10 emits light that passes through the fan and is received by the optical fiber receiving end 20. When the blade gap of the fan passes through the light, the optical fiber receiving end 20 and the transmitting end 10 are still connected. On the contrary, when the fan blade rotates between the receiving end 20 and the transmitting end 10, the light is disconnected. As the fan blade rotates continuously, the light is in a state of connection, disconnection, connection... The sensor can generate pulse signals of 0, 1, 0, 1, 0, 1... in real time. Of course, the optical fiber sensor can also be replaced by a laser, a proximity switch, or even a travel switch, etc. Any sensor that can achieve similar digital quantity signal acquisition can be used.

[0020] The monitoring system also includes a controller 50, which is used to receive the pulse signal. By calculating the number of pulses within a unit time, the greater the pulse value within a unit time, the faster the fan speed, and the smaller the pulse value, the slower the speed. Thus, the actual fan rotation speed value is obtained. By setting several corresponding pulse thresholds and setting that feedback is given when the number of pulses within a unit time is lower than a certain value, and an alarm signal is issued for alarm when it is lower than the dangerous value.

[0021] The optical fiber sensor also includes an optical fiber amplifier 30, which is used to amplify the pulse signal and output it to the controller. In addition, the controller also includes a timing interrupt organizing module 40, which edits and accumulates the received pulse signals.

[0022] The monitoring system also includes a temperature measurement sensor 60, such as a high-precision K-type thermocouple, etc., which is disposed at the air outlet of the fan to be measured, used to detect the air temperature at the air outlet, and input it to the controller to calculate the actual temperature value in the air. When the measured air temperature suddenly rises and is greater than the set temperature threshold and lasts for a corresponding time, an alarm signal is issued.

[0023] In addition, in a non-ventilated environment, the stoppage of the fan will directly cause the temperature in a certain area to rise. Therefore, the monitoring system can also include a temperature measurement sensor disposed at the air outlet of the fan to be measured, used to detect the air temperature at the air outlet, and input it to the controller to calculate the actual temperature value in the air. The specific calculation can be obtained by multiplying the actual measured value by 0.1 to get the actual temperature value of the air. When the measured air temperature suddenly rises, is greater than the set temperature threshold and lasts for a corresponding time (generally set to last for 1S), it can be indirectly judged that the fan has a fault, and an alarm signal is issued.

[0024] The above two detection measures are in an "or" relationship, that is, an alarm will be triggered as long as one of them takes effect, which is a two-layer insurance to avoid accidents. By using the monitoring system and method of the present invention, there is no need to repeatedly purchase hardware, and the on-site controller resources such as PLC, PC, SCM, etc. can be fully utilized, avoiding the adverse effects caused by the feedback of the DC circuit in the prior art, being able to monitor the running state of the fan in real time and effectively, and being able to receive abnormal signals before an accident occurs and handle them in time, so as to accurately and digitally control the site.

[0025] However, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. As long as within the scope of the spirit of the present invention, changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A fan status monitoring system, characterized in that, Comprising: An optical fiber sensor, including an optical fiber transmitting end and an optical fiber receiving end respectively arranged on the front and back sides of the fan to be measured, which detects the rotating fan blades and generates pulse signals in real time; A controller, which receives the pulse signals, obtains the actual fan speed value by calculating the number of pulses within a unit time, and sets corresponding pulse thresholds. When the number of pulses within a unit time is lower than the corresponding pulse threshold, an alarm signal is issued.

2. The fan status monitoring system according to claim 1, wherein: The optical fiber sensor further includes an optical fiber amplifier, which amplifies the pulse signals and outputs them to the controller.

3. The fan status monitoring system according to claim 1, characterized in that: The controller includes a timing interrupt organization module, which edits and accumulates the received pulse signals.

4. The fan status monitoring system according to claim 1, wherein: The monitoring system further includes a temperature measuring sensor, which is arranged at the air outlet of the fan to be measured, used to detect the air temperature at the air outlet, and inputs it to the controller to calculate the actual temperature value in the air. When the measured air temperature suddenly rises and is greater than the set temperature threshold and lasts for a corresponding time, an alarm signal is issued.

5. The monitoring method of the fan status monitoring system according to claim 1, characterized in that, Including the following steps: A. Respectively set an optical fiber transmitting end and an optical fiber receiving end on the front and back sides of the fan to be measured, and detect and generate pulse signals by the rotating fan blades intermittently crossing the emitted light; B. Receive the pulse signals through the controller, obtain the actual fan speed value by calculating the number of pulses within a unit time, and set corresponding pulse thresholds. When the number of pulses within a unit time is lower than the corresponding pulse threshold, an alarm signal is issued.

6. The monitoring method according to claim 5, wherein: In step A, a temperature measuring sensor is also arranged at the air outlet of the fan to be measured, used to detect the air temperature at the air outlet, and inputs it to the controller to calculate the actual temperature value in the air. When the measured air temperature suddenly rises and is greater than the set temperature threshold and lasts for a corresponding time, an alarm signal is also issued.

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