System and method for controlling an expansion system

A waste heat recovery system, comprising:

• a heat source;
• a rankine cycle system comprising an expander, wherein the rankine cycle system is coupled to the heat source and configured to circulate a working fluid, wherein the rankine cycle system is configured to remove heat from the heat source;
• and
• a control system coupled to the heat source and the rankine cycle system, the control system comprising:
• a temperature sensor communicatively coupled to an exit of the expander and configured to detect temperature of the working fluid flowing through the exit of the expander;
• a pressure sensor communicatively coupled to the exit of the expander and configured to detect pressure of the working fluid flowing through the exit of the expander, and
• a controller configured to receive output signals from the temperature sensor and the pressure sensor and configured to control thermodynamic conditions at the exit of the expander so as to drive a quality of vapor of the working fluid at the exit of the expander towards a predetermined degree of superheat.

A method for controlling thermodynamic conditions at an exit of an expander of an expansion system;

• the method comprising:
• detecting temperature of the working fluid flowing through the exit of the expander;
• detecting pressure of the working fluid flowing through the exit of the expander;
• and
• controlling operation of one or more components of the expansion system based on detected temperature and pressure of the working fluid flowing through the exit of the expander so as to drive a quality of vapor of the working fluid at the exit of the expander towards a predetermined degree of superheat.

A method comprising:

• circulating a working fluid through a rankine cycle system coupled to a heat source, wherein circulating the working fluid comprises removing heat from the heat source;
• and
• detecting temperature of the working fluid flowing through an exit of an expander of the rankine cycle system;
• detecting pressure of the working fluid flowing through the exit of the expander of the rankine cycle system;
• and
• controlling one or more components of the rankine cycle system, heat input from the heat source, or a combination thereof based on detected temperature and pressure of the working fluid flowing through the exit of the expander so as to drive a quality of vapor of the working fluid at the exit of the expander towards a predetermined degree of superheat.