Patent ID: 8850814
Filing Date: 2014-10-07
Classification: F01K

Abstract:
1. A waste heat recovery system, comprising: a) an internal combustion engine supplying an engine exhaust to provide a high grade waste heat thermal resource fluid at a temperature of 250-500° C., and a low grade waste heat thermal resource fluid; b) an intermediate thermal cycle having water as an intermediate fluid, which is vaporized with heat from said high grade waste heat thermal resource fluid and which is expanded within a first, steam turbine, producing power; and c) an organic thermal cycle having an organic motive fluid, which is preheated with heat from said low grade waste heat thermal resource fluid and which is vaporized with heat from the discharge of said intermediate fluid from said first, steam turbine, the vaporized organic motive fluid being expanded in a second, organic fluid turbine, producing power, d) a combined condenser-vaporizer unit (CVU), the discharge of the intermediate fluid from the first turbine being in heat exchanger relation with the preheated organic motive fluid at the combined condenser-vaporizer unit (CVU) whereat the organic motive fluid is vaporized and the intermediate fluid is condensed, e) a boiler bringing the condensed intermediate fluid in heat exchanger relation with the high grade thermal resource fluid at a boiler and is vaporized thereby, wherein the boiler comprises a first stage boiler and a second stage boiler, and f) first and second conduits exiting the CVU and extending to the first and second stage boilers, respectively, wherein the condensed intermediate fluid exits the CVU via the first and second conduits, the high grade thermal resource fluid exiting the internal combustion engine being delivered to the first stage boiler to generate high pressure intermediate fluid for supply to the first turbine and the high grade thermal resource fluid exiting the first stage boiler being delivered to the second stage boiler to generate low pressure intermediate fluid for combining with said discharge of the intermediate fluid from the first turbine so that the combined fluid is supplied to the CVU, and so that the heat present in the combined fluid is used to produce said vaporized organic fluid which is expanded in said organic fluid turbine to produce power.