Working Fluid For An Orc Process, Orc Process and Orc Apparatus

Abstract

The invention relates to working fluids for energy conversion in a thermal ORC process for combined generation of electrical and heat energy. The heat source used is in particular thermal water. The working fluids used are partially or perfluorinated hydrocarbons and/or partially or perfluorinated polyethers and/or partially or perfluorinated ketones. In one embodiment of the invention, the working fluid used is a combination of 1,1,1,3,3-pentafluorobutane and a fluorinated polyether having a molecular weight of 340 and a boiling point of 57° C. at 101.3 kPa.

1 . A working fluid for an ORC process, comprising or consisting of at least one compound selected from the group of the partially or perfluorinated hydrocarbons and/or at least one compound from the group of the partially or perfluorinated polyethers and/or at least one compound from the group of the partially or perfluorinated ketones or a mixture of these compounds with one another. 
     
     
         2 . A working fluid for an ORC process according to  claim 1 , wherein the partially or perfluorinated hydrocarbon is at least one compound from the group of tetrafluoroethane, pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane, hexafluorobutane, heptafluorobutane, decafluoropentane, perfluoropentane, perfluorohexane or mixtures thereof. 
     
     
         3 . A working fluid according to  claim 2  further comprising at least one partially or perfluorinated polyethers. 
     
     
         4 . A working fluid according to  claim 1 , wherein the partially or perfluorinated polyethers have a boiling point greater than or equal to 40° C. at 101.3 kPa. 
     
     
         5 . A working fluid according to  claim 1 , wherein the partially or perfluorinated ethers have a boiling point equal to or less than about 200° C. at 101.3 kPa. 
     
     
         6 . A working fluid according to  claim 1 , comprising or consisting of a mixture of 1,1,1,3,3-pentafluorobutane and at least one perfluorinated polyether. 
     
     
         7 . A working fluid according to  claim 1 , wherein the at least one perfluorinated polyether has a boiling point of about 57° C. at 101.3 kPa. 
     
     
         8 . A working fluid according to  claim 1 , wherein the partially or perfluorinated ketones are selected from compounds having the general formula R—C(O) —R′, where R is an alkyl group, or a linear or branched fluorinated C1-C6-alkyl group in which not more than two fluorine atoms may be replaced by hydrogen, and R′ is a linear or branched fluorinated C1-C6 alkyl group in which not more than two fluorine atoms may be replaced by hydrogen. 
     
     
         9 . A working fluid according to  claim 1 , wherein the fluorinated ketones are selected from the group consisting of CF 3 C(O)CF(CF 3 ) 2 , CF 3 CF 2 C(O)CF(CF 3 ) 2 , CH 3 C(O)CF 2 CF 2 H, CH 3 C(O)CF 2 CFHCF 3 . 
     
     
         10 . A working fluid according to  claim 9 , comprising or consisting of a mixture of 1,1,1,3,3-pentafluorobutane and CF 3 C(O)CF(CF 3 ) 2 . 
     
     
         11 . An ORC process for converting heat into electrical energy wherein an ORC working fluid according to  claim 10  is used as ORC working fluid. 
     
     
         12 . An apparatus for performing an ORC process comprising an ORC working fluid according to  claim 1 . 
     
     
         13 . The working fluid for an ORC process according to  claim 2 , wherein the partially or perfluorinated hydrocarbon is at least one compound from the group of 1,1,1,2-tetrafluoroethane, 1,1,1,3,3-pentafluoropropane, hexafluoropropane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1,3,3-pentafluorobutane, hexafluorobutane, hepafluorobutane, decafluoropentane, perfluorohexane or mixtures thereof. 
     
     
         14 . The working fluid according to  claim 8 , wherein the partially or perfluorinated ketones are selected from compounds having the general formula R—C(O)—R′, where R is a methyl group, and R′ is a linear or branched fluorinated C1-C6 alkyl group in which not more than two fluorine atoms may be replaced by hydrogen.