A control system of a fan drive based on airflow doppler ultrasonic control

Аннотация

The control system of a fan drive based on control of the integral (section-average) velocity of the generated airflow is proposed. For this purpose, the flow velocity (rate) is measured using a Doppler ultrasonic device. The results of laboratory experiments under simultaneous contact and remote control of the flow and rotation speed of the fan in the steady-state and transient modes shows that the ultrasonic device can be integrated into the control system. Corresponding elements and their transfer functions for the automatic-control system (ACS) of the fan unit are identified. The stability is determined, and the results of simulation modeling of operation of a closed-loop system in which the integral velocity of the airflow is assumed to be a regulated variable value are given. The drive of the fan unit should be controlled taking into account the changes of the aerodynamic characteristics of the system: the positions of the curtains, blinds, shutters, etc. The proposed approach made it possible to carry out the noncontact control of an open airflow at the system output independently of the drive type and fan itself and introduce appropriate modifications into the traditional algorithms of automated control of drives of fans, curtains, and shutters.