Characterization of Limacon Gas Expanders With Consideration to the Dynamics of Apex Seals and Inlet Control Valve

Abstract

Limaçon machine, of which the relative motion between the rotor and housing follows the limaçon curve, belongs to a class of rotary positive displacement machines. The profiles of rotors and housings of those machines can be constructed of either limaçon or circular curves, hence the names: limaçon-to-limaçon, circolimaçon, and limaçon-to-circular machines. This paper presents the investigation into the thermodynamic performance of the limaçon-to-circular machines with the presence of apex seals and inlet valve. This paper sets out by briefly introducing the limaçon technology and the construction of the limaçon-to-circular machine working volume. The mathematical descriptions of ports' positions and areas have also been introduced. The paper then discusses the flow and phase composition of working fluid through the working chambers as well as how the fluid velocity is modeled and calculated. Then the seal dynamic model and response of inlet valve are presented followed by the machine thermodynamic model. A case study has also been presented to show the responses of seals and inlet valve during the machine operation.

An Optimum Design for a Fast-Response Solenoid Valve: Application to a Limaçon Gas Expander

“…It is evident that a control valve capable of regulating the fluid flow irrespective of the rotor position would be more beneficial in that regard. In that context, Phung et al proposed a push-pull solenoid valve for a limaçon gas expander and demonstrated the valve response during machine operation [35]. However, the valve is not optimized in conjunction with the application of the limaçon gas expander as the speed of response of the valve was less compared to that of the machine.…”