ddeshi2
Member
Hi all, I'm new to PLC programming and this is my first project. In our project we feed water, Methane and air to the combustion chamber. For feeding air we are using two control valves (Low air and Large air) and measuring flowrate using a single flow meter.Low air valve is opened during initial stages of the process and Large Air is opened after a certain period of time(as required by the process).The specifications of control valves are:
Low Air: Min-2.5 SCFM, Max: 10 SCFM
Large Air: Min-10 SCFM, Max: 100 SCFM
So , if I want a total flow rate of 90 SCFM I'll open the Low Air first till I get 10 SCFM and then open the Large Air to get a total of 90 SCFM..How can I set up PID Loops for this?? should I use two PID loops one for Low Air, one for Large Air? And if I want a total flow rate of 90 SCFM ..Should I input this value through HMI as a set point to the Low Air Valve PID Loop (but the control valve Max is 10 SCFM only)??or should I use 10 SCFM as the setpoint and then open the Large Air valve and ramp up the setpoint to 90 SCFM??? please help..
Thank you,
Ding
Low Air: Min-2.5 SCFM, Max: 10 SCFM
Large Air: Min-10 SCFM, Max: 100 SCFM
So , if I want a total flow rate of 90 SCFM I'll open the Low Air first till I get 10 SCFM and then open the Large Air to get a total of 90 SCFM..How can I set up PID Loops for this?? should I use two PID loops one for Low Air, one for Large Air? And if I want a total flow rate of 90 SCFM ..Should I input this value through HMI as a set point to the Low Air Valve PID Loop (but the control valve Max is 10 SCFM only)??or should I use 10 SCFM as the setpoint and then open the Large Air valve and ramp up the setpoint to 90 SCFM??? please help..
Thank you,
Ding