Method and system for generating power from low- and mid- temperature heat sources using supercritical rankine cycles with zeotropic mixtures

摘要

A method and system for generating power from low- and mid-temperature heat sources using a zeotropic mixture as a working fluid. The zeotropic mixture working fluid is compressed to pressures above critical and heated to a supercritical state. The zeotropic mixture working fluid is then expanded to extract power. The zeotropic mixture working fluid is then condensed, subcooled, and collected for recirculation and recompression.

主权项

1. A system for generating power from a low- and mid-temperature heat source using a zeotropic mixture working fluid within a closed-loop supercritical Rankine cycle, comprising:
a pump for compressing said zeotropic mixture working fluid beyond its critical pressure, said zeotropic mixture working fluid having one critical curve and isobaric boiling curve; a first heat exchanger in communication with said pump and said heat source for exchanging heat between said zeotropic mixture working fluid and said heat source, said zeotropic mixture working fluid being superheated to a supercritical state; a first turbine in communication with said heat exchanger for expanding said superheated zeotropic mixture working fluid for exporting mechanical work; a first generator in communication with said first turbine for converting said work to power; a condenser in communication with said first turbine for condensing and subcooling said zeotropic mixture working fluid, said condenser having a cooling agent, said zeotropic mixture working fluid having a thermal glide during isobaric condensation such that said thermal glide of said zeotropic mixture working fluid substantially matches a temperature profile of said cooling agent to minimize irreversibility and exergy loss; and a surge vessel in communication with said condenser and said pump for collecting said zeotropic mixture working fluid for recirculation and recompression.