The present invention is directed to a direct-drive fan
system and a variable
process control system for efficiently managing the operation of fans in a cooling
system such a as wet-
cooling tower or air-cooled
heat exchanger (ACHE),
HVAC systems, mechanical towers or
chiller systems. The present invention is based on the integration of key features and characteristics such as
tower thermal performance, fan speed and
airflow,
motor torque, fan
pitch, fan speed, fan aerodynamic properties, and pump flow. The variable
process control system processes feedback signals from multiple locations in
order control a
high torque, variable speed,
permanent magnet motor to drive the fan. Such feedback signals represent certain operating conditions including motor temperature, basin temperature, vibrations, and pump flow rates. Other data processed by the variable
process control system in order to control the motor include
turbine back pressure set-point, condenser temperature set-point and
plant part-load setting. The variable process
control system processes this data and the aforesaid feedback signals to optimize the operation of the cooling system in order to prevent disruption of the industrial process and prevent equipment (
turbine) failure or trip. The variable process
control system alerts the operators for the need to conduct
maintenance actions to remedy deficient operating conditions such as condenser
fouling. The variable process
control system increases cooling for
cracking crude and also adjusts the motor RPM, and hence the fan RPM, accordingly during
plant part-load conditions in order to save energy.