Systems and methods for power generation from multiple heat sources using customized working fluids

Abstract

A power generating system in one embodiment employs a Rankine Cycle system that is coupled to multiple heat sources. The Rankine cycle system includes a customized working fluid that comprises a mixture of a plurality of constituent fluids, the selection of which causes the mixture to exhibit a working fluid profile. In one embodiment, the working fluid profile includes a temperature glide portion selected and optimized based on operating conditions of the heat sources, wherein the temperature glide portion includes a constituent phase point at which one of the constituent fluids undergoes a phase change before the other constituent fluids of the mixture.

What is claimed is: 
     
         1 . A power generating system comprising:
 a heat source; and   a customized working fluid in heat exchange relation to the heat source, the customized working fluid comprising a mixture of constituent fluids, the mixture exhibiting a working fluid profile comprising at least one constituent phase point at which at least one of the constituent fluids undergoes a phase change before the other constituent fluids of the mixture.   
     
     
         2 . A power generating system according to  claim 1 , wherein the constituent fluids comprise at least one organic fluid. 
     
     
         3 . A power generating system according to  claim 1 , wherein the heat source comprises a first heat source and a second heat source, and wherein the customized working fluid exchanges heat with each of the first heat source and the second heat source. 
     
     
         4 . A power generating system according to  claim 1 , wherein the working fluid profile includes a constituent phase point for each of the constituent fluids of the mixture, and wherein the constituent phase points define different temperatures at which occur the phase change. 
     
     
         5 . A power generating system according to  claim 1 , further comprising a heat exchange system coupled to the heat source and in which flows the customized working fluid, the heat exchange system comprising at least one of a pump, an evaporator, a condenser, and a turbine generator. 
     
     
         6 . A power generating system according to  claim 1 , wherein the mixture comprises a first constituent fluid and a second constituent fluid, and wherein the constituent phase point identifies a portion of the working fluid profile at which the phase change of first constituent fluid is completed before the phase change of the second constituent fluid. 
     
     
         7 . A power generating system according to  claim 1 , wherein at least one of the constituent fluids is compatible with operation in a Rankine cycle system. 
     
     
         8 . A power generating system according to  claim 1 , wherein at least one of the first constituent fluid and the second constituent fluid comprises one or more of a hydrofluorocarbon, a hydrocarbon, a fluorinated ketone, a fluorinated ether, a chloro- and bromo-fluoro olefin, a hydrofluoroolefins, a hydrofluoroolefin ether, a hydrochlorofluoroolefin ether, a linear siloxane, a cyclic siloxane, and combinations and derivations thereof. 
     
     
         9 . In a power generating system comprising a first heat source having a first temperature and a second heat source having a second temperature that is greater than the first temperature, the power generating system employing a Rankine cycle system comprising:
 a heat exchange system coupled to each of the first heat source and the second heat source; and   a customized working fluid flowing in the heat exchange system, the customized working fluid comprising a first constituent fluid and a second constituent fluid,   wherein the first constituent fluid undergoes a phase change before the second constituent fluid.   
     
     
         10 . A system according to  claim 9 , wherein at least one of the first constituent fluid and the second constituent fluid is an organic fluid compatible with the Rankine cycle system. 
     
     
         11 . A system according to  claim 9 , wherein the first constituent fluid completely vaporizes before the second constituent fluid. 
     
     
         12 . A system according to  claim 9 , wherein the first constituent fluid completely condenses before the second constituent fluid. 
     
     
         13 . A system according to  claim 9 , wherein the heat exchange system comprises at least one of a pump, an evaporator, a condenser, and a turbine generator. 
     
     
         14 . A system according to  claim 9 , wherein the first constituent fluid and the second constituent fluid comprise a compound that is selected from the group consisting of propane, cyclopropane, isobutene, isobutane, n-butane, propylene, n-pentane, isopentane, cyclopentane, R-134a, R-30, R-32, R-123, R-125, R-143a, R-134, R-152a, R-161, R-1216, R-227ea, R-245fa, R-245cb, R-236ea, R-236fa, R-365mfc, HT-55, R-43-10mee, HFE-7000, Novec-649, CF 3 I, R-1234 (ye and yf), R-1234ze, R-1233 (zd(E) and zd(Z)), R-1225 (ye(Z) and ye(E)), C 5 F 9 Cl, C 5 H 2 F 10 , R-1243zf, E-134a, E134, E125, E143a, siloxane MM, dimethylether, and CO 2 , and combinations and derivations thereof. 
     
     
         15 . A system comprising:
 a plurality of heat sources;   a power generator coupled to each of the plurality of heat sources; and   a plurality of customized working fluids flowing in the power generator,   wherein each of the customized working fluids comprises a mixture of a plurality of constituent fluids, and   wherein the mixture exhibits a working fluid profile with at least one constituent phase point at which one of the plurality of constituent fluids undergoes a phase change before any of the other of the plurality of constituent fluids.   
     
     
         16 . A system according to  claim 15 , wherein the power generator comprises a plurality of heat exchange systems that flow the customized working fluid in heat transfer relation to the heat sources. 
     
     
         17 . A system according to  claim 15 , wherein the constituent fluids comprise one or more of a hydrofluorocarbon, a hydrocarbon, a fluorinated ketone, a fluorinated ether, a chloro-fluoro olefin, a bromo-fluoro olefin, a hydrofluoroolefin, a hydrofluoroolefin ether, a hydrochlorofluoroolefin ether, a linear siloxane, a cyclic siloxane, and combinations and derivations thereof. 
     
     
         18 . A system according to  claim 15 , wherein the first constituent fluid and the second constituent fluid comprise compounds selected from the group consisting of propane, cyclopropane, isobutene, isobutane, n-butane, propylene, n-pentane, isopentane, cyclopentane, R-134a, R-30, R-32, R-123, R-125, R-143a, R-134, R-152a, R-161, R-1216, R-227ea, R-245fa, R-245cb, R-236ea, R-236fa, R-365mfc, HT-55, R-43-10mee, HFE-7000, Novec-649, CF 3 I, R-1234 (ye and yf), R-1234ze, R-1233 (zd(E) and zd(Z)), R-1225 (ye(Z) and ye(E)), C 5 F 9 Cl, C 5 H 2 F 10 , R-1243zf, E-134a, E134, E125, E143a, siloxane MM, dimethylether, and CO 2 , and combinations and derivations thereof.