System for controlling admission volume of inlet gas for fixed RPM operation of rotary or reciprocating expander

A system (500) for controlling admission volume of an inlet gas for fixed RPM operation in an apparatus, comprising:

• a pressure reducing valve PRV) (504) for controlling a boiler pressure to a process pressure;
• a boiler (502) for generating a steam for heating application in a process, wherein the pressure of the stream is higher than process pressure;
• two inlets valves (606a and 606b);
• two exhaust valves (610a and 610b), wherein the inlet valves (606a and 606b) and the exhaust valves (610a and 610b) are configured by intersection of opening on a rotor housing (614) ports and opening on a rotating valve,
• wherein the inlet valves are designed in such a way that a valve opening duration is controlled to admit required volume of a steam corresponding to a mass flow requirement of the process,
• wherein the valve capable of changing duration and timing of opening in such a way that the duration and starting of exhaust is controlled;
• wherein the rotating valve is timed and profiled in such a way that the rotating valve opens the rotor housing ports only for a stipulated period which can be dynamically varied based on mass flow requirement of the process.