Patent ID: 8650879

Claim:
A waste heat recovery system, comprising: a first organic rankine cycle system for circulating a first organic working fluid, the first organic rankine cycle system configured in a high temperature loop including an exhaust heat exchanger, a high temperature expander, a cascade heat exchanger and a pump, wherein the first exhaust heat exchanger receives heat generated by to a first heat source and generates a first organic working fluid vapor for driving the high temperature expander to produce useful work, and wherein the cascade heat exchanger condenses the first organic working fluid vapor into liquid that is pumped back to the exhaust heat exchanger; and a second organic rankine cycle system for circulating a second organic working fluid, the second organic ranking cycle system configured in a low temperature loop including the cascade heat exchanger of the first organic rankine cycle system, a low temperature expander, a low temperature condenser, a low temperature pump and one or more preheaters, wherein the cascade heat exchanger of the first organic rankine cycle system receives heat from the second heat source and the first organic working fluid and generates a second organic working fluid vapor for driving the low temperature expander to produce useful work, and wherein the low temperature condenser condenses the second organic working fluid vapor into liquid that is pumped back to the second heat source, and wherein the one or more preheaters comprise one or more charge air coolers for heating the second organic working fluid while cooling incoming charge air flow from a turbo-charger positioned upstream of the one or more preheaters.