Thanks for the help all.
JFletcher - can you suggest any reading that might help me better understand generator load and frequency? I assumed that you could speed up or slow down the rotations based on resistance/load. Obviously I have a lot to learn, any help is appreciated.
Gar - you are describing what I am trying to accomplish. By attaching a dynamometer you would put additional load on the generator which would slow down the rotation of the generator?? What would you suggest can be added to the system to capture this lost energy?
Noswad4, you need to more clearly define your system. I am not sure if you were talking about one piece of equipment or multiple types of systems. Do you have a windmill connected to an air turbine connected to a gearbox connected to a generator? Is that generating AC or DC? How many generators are we talkin about?
on the generator side of things, in the most basic sense you are going to generate as much power as your loads demand.
The amount of power produced by the turbine (your prime mover) is going to be largely dependent on the pressure drop across its blades. When the air is provided by CAES, your turbine intake pressure is going to decrease as that stored air is used up.
I asked about the 50 psi discharge or exhaust pressure because, as mentioned above, the power your turbine produces largely depends on the pressure drop across the blades. You may have little to no practical control over the demand on the grid and thus the power your generator needs to make. When running on compressed air, you also have little control over that variable. Varying the exhaust pressure of your turbine is one way to achieve the desired power it needs to produce
The amount of power your prime mover produces has to equal that of the demand on the generator, plus any inefficiencies and system losses. While you can vary certain parameters within the generator, if the loads on it are, say, 10 kilowatts, your prime mover is going to need to produce the same amount of power.
Coupling this with a windmill changes a few things, however your generator and turbine work the same.
If you wish to increase efficiency, or capture lost energy, or store more potential energy, there are many schemes employed to do this. Your stored air, there are heating systems to increase its energy. Battery banks are a way to store energy until it is needed.
A higher pressure drop across your turbine would probably be the easiest to implement, at least in theory. By your numbers, if your turbine can withstand a 500 PSI intake pressure, and a 50 psi discharge pressure, it can withstand a 450 psi delta. When your air pressure is down to 200 psi, if your discharge pressure was effectively 0, or atmospheric at 14.7 PSI at sea level, you now have a 185 to 200 psi delta across the blades instead of 150. In theory, this could increase turbine efficiency by 20 to 30%.
In practice however, turbines and windmills are not designed by people like me, they are designed by top level engineers at companies like Siemens that make a heck of a lot more cash than I do.
Hope that helps some. And welcome to the Forum.
