In college, a simple transfer function was given and we were asked to tune the PID which is what I am trying to do, I cant do this without the transfer function of the real model and I do not know how to get acquire it myself?
I have a degree in ME, and I am struggling to create a mathematical model to simulate a humidifier in an HVAC system.
The final goal is to model the rate of change of humidity going into a room and being returned through the duct knowing the CFM, air changes per hour, max load of the humidifier, and rate of change in the room itself as the humidifier adds moisture to the air in %RH. (Input to the PID is setpoint in %RH, room %RH being read, and output is amount of humidification to add, based on the valve position… which can be assumed %RH to add to the stream)
TL;DR: How do I model a humidifier in an HVAC system with a transfer function to tune the PID controls?
I assumed that 1/(0.1s+1) would be a simple start for the sensor lag back to the controller, but how do i model the humidity being added to the room (i assumed based on volume, max flow rate from the humidifier or current position, and percent of this air being returned through the duct),
Any help is greatly appreciated!