Class
Article
College
College of Engineering
Faculty Mentor
Geordie Richards
Presentation Type
Oral Presentation
Abstract
Expanders allow pressurized fluids to undergo expansion in a controlled environment for the purpose of extracting energy from the fluid. The energy is converted to mechanical shaft power used to drive a generator or any other rotational load. As many types of expanders exist, this research analyzes the isentropic efficiency of a planetary rotary type expander (PRE) by performing a rigorous geometrical analysis. The geometric relationships allow modeling of the cavity mass flowrate, and PRE leakage flowrate in order to calculate the PRE’s isentropic efficiency. This research not only provides the capability of modeling the PRE’s efficiencies for different rotor sizes and speed, but also the model converges to an isentropic efficiency maximum yielding an optimized configuration. This allows a PRE to be designed specifically for an application in industry, where previously there was no method. The developed model allows for rotor length, machine radius, and machine speed variance. Calculations are performed using real gas analysis, which requires a multi-level iterative solver approach. The model also presents 2 primary applications in industry where the calculation methods are different. The first being a target power application where the user seeks to match a required electrical load the expander must provide. In this application, high efficiencies are achieved by the PRE extracting energy utilizing as little mass flowrate as possible. The second application is total energy recovery, where the user seeks to maximize power output of a flow while maintaining a mass flowrate driven by the flow requirements. While both applications use the same model, the energy recovery application gives a mass flowrate as a constraint, where no analytical solution exists. An objective solver is developed along with the real gas iterative solver to converge to an optimized machine size and rotational speed
Location
Room 421
Start Date
4-12-2018 9:00 AM
End Date
4-12-2018 10:15 AM
PRE Expanders: Handling More Than Just Pressure
Room 421
Expanders allow pressurized fluids to undergo expansion in a controlled environment for the purpose of extracting energy from the fluid. The energy is converted to mechanical shaft power used to drive a generator or any other rotational load. As many types of expanders exist, this research analyzes the isentropic efficiency of a planetary rotary type expander (PRE) by performing a rigorous geometrical analysis. The geometric relationships allow modeling of the cavity mass flowrate, and PRE leakage flowrate in order to calculate the PRE’s isentropic efficiency. This research not only provides the capability of modeling the PRE’s efficiencies for different rotor sizes and speed, but also the model converges to an isentropic efficiency maximum yielding an optimized configuration. This allows a PRE to be designed specifically for an application in industry, where previously there was no method. The developed model allows for rotor length, machine radius, and machine speed variance. Calculations are performed using real gas analysis, which requires a multi-level iterative solver approach. The model also presents 2 primary applications in industry where the calculation methods are different. The first being a target power application where the user seeks to match a required electrical load the expander must provide. In this application, high efficiencies are achieved by the PRE extracting energy utilizing as little mass flowrate as possible. The second application is total energy recovery, where the user seeks to maximize power output of a flow while maintaining a mass flowrate driven by the flow requirements. While both applications use the same model, the energy recovery application gives a mass flowrate as a constraint, where no analytical solution exists. An objective solver is developed along with the real gas iterative solver to converge to an optimized machine size and rotational speed