Patent ID: 8544274

Claim:
A method of recovering energy from dual sources of waste heat having differing temperatures using a single organic fluid, comprising: a) providing a first waste heat source; b) providing a second waste heat source, said second waste heat source having a temperature higher than said first waste heat source; c) providing a first heat exchanger; d) passing a first heat conveying medium from said first waste heat source through said first heat exchanger; e) providing a first pump to pressurize said organic fluid to a first pressure; f) passing said organic fluid through said first heat exchanger; g) directing said organic fluid from said first heat exchanger through a first turbine; h) directing the organic fluid from said first turbine through a cooling condenser; i) providing a second pump positioned downstream of said cooling condenser to pressurize said organic fluid to a second pressure, said second pressure being greater than said first pressure; j) providing a second heat exchanger; k) passing a second heat conveying medium from said second waste heat source through said second heat exchanger; l) passing the pressurized organic fluid, exiting said second pump, through said second heat exchanger; and m) directing said organic fluid from said second heat exchanger through a second turbine.