Turbine waste heat recovery expander with passive method for system flow control

An organic Rankine cycle waste heat recovery system for recovering waste heat of an internal combustion engine, said waste heat recovery system comprising:

• an evaporator for transferring heat discarded by an internal combustion engine to a working fluid;
• a turbine expander for outputting power based on the working fluid, said turbine expander comprising:
• a turbine blade rotatable by the working fluid,
• a shaft coupled to and rotatable by the turbine blade, with the shaft extending along a longitudinal axis,
• a nozzle assembly for directing the working fluid to the turbine blade for rotating the turbine blade, the nozzle assembly including a nozzle housing disposed about the shaft and adjacent the turbine blade, and a nozzle component coupled to the nozzle housing for accelerating the working fluid, the nozzle component defining a nozzle throat having a geometrical configuration, and
• a passive control coupled to the nozzle component for directing the working fluid, the passive control including a channel in fluid connection with the nozzle, wherein the channel is formed at an inlet of the nozzle assembly, and a seal being in apposition across an interior width of the channel, and the seal configured to move from a closed position to an open position when the working fluid comes in contact with the seal;
• a condenser in fluid communication with the turbine expander to condense the working fluid from a vapor state to a liquid state;
• and
• a pump to circulate a working fluid from the condenser to the evaporator.

A method of recovering waste heat of an internal combustion engine, comprising:

• providing a turbine expander for outputting power based on a working fluid, the turbine expander comprising:
• a turbine blade rotatable by the working fluid,
• a shaft coupled to and rotatable by said turbine blade, with said shaft extending along a longitudinal axis,
• a nozzle assembly for directing the working fluid to the turbine blade for rotating the turbine blade, the nozzle assembly including a nozzle housing disposed about the shaft and adjacent the turbine blade, and one or more nozzle components coupled to the nozzle housing for accelerating the working fluid, with each of the one or more nozzle components defining a nozzle throat having a geometrical configuration, and
• one or more passive controls each coupled to the one or more nozzle components for directing the working fluid to their respective coupled nozzle components, each of said one or more passive controls including a channel in fluid connection with their respective coupled nozzles, wherein the channel is formed at an inlet of the nozzle assembly, and including a seal being in apposition across an interior width of the channel, and the seal moves from a closed position to an open position when the working fluid comes in contact with said seal;
• directing a first portion of the working fluid to a first passive control of the one or more passive controls;
• and
• receiving the working fluid at a first nozzle component of the one or more nozzle components.