Working medium and heat cycle system

Abstract

To provide a working medium for heat cycle which has less influence over the ozone layer, which has less influence over global warming and which provides a heat cycle system excellent in the cycle performance (the efficiency and the capacity), and a heat cycle system excellent in the cycle performance (the efficiency and the capacity). A working medium for heat cycle comprising 1,2-difluoroethylene is employed for a heat cycle system (such as a Rankine cycle system, a heat pump cycle system, a refrigerating cycle system 10 or a heat transport system).

1 - 13 . (canceled) 
     
     
         14 . A working medium for heat cycle, comprising:
 1,2-difluoroethylene,   at least one hydrofluoroolefin other than 1,2-difluoroethylene, and   optionally, at least one hydrofluorocarbon.   
     
     
         15 . The working medium of  claim 14 , comprising the at least one hydrofluorocarbon. 
     
     
         16 . The working medium of  claim 15 , wherein the at least one hydrofluorocarbon is difluoromethane. 
     
     
         17 . The working medium of  claim 14 , comprising at least 60 mass %, based on the mass of the working medium, of the 1,2-difluoroethylene. 
     
     
         18 . The working medium of  claim 15 , comprising from 1 to 30 mass %, based on the mass of the working medium, of the at least one hydrocarbon. 
     
     
         19 . The working medium of  claim 18 , wherein the at least one hydrocarbon is selected from the group consisting of propane, propylene, cyclopropane, butane, isobutane, pentane, and isopentane. 
     
     
         20 . The working medium of  claim 14 , comprising from 1 to 99 mass %, based on the mass of the working medium, of difluoromethane. 
     
     
         21 . The working medium of  claim 14 , comprising from 1 to 60 mass %, based on the mass of the working medium, of difluoromethane. 
     
     
         22 . The working medium of  claim 14 , comprising difluoromethane and pentafluoroethane. 
     
     
         23 . The working medium of  claim 14 , further comprising at least one compound selected from the group consisting of a hydrochlorofluoroolefin or a chlorofluoroolefin. 
     
     
         24 . The working medium of  claim 23 , wherein a total content of the hydrochlorofluoroolefin and the chlorofluoroolefin is from 1 to 60 mass %, based on the mass of the working medium. 
     
     
         25 . A heat cycle system, comprising the working medium according to  claim 14 , an evaporator, a compressor, a condenser, an expansion valve, and a load fluid. 
     
     
         26 . The working medium of  claim 14 , wherein the 1,2-difluoroethylene is (E)-1,2-difluoroethylene.