Composition for heat cycle system, and heat cycle system

Abstract

To provide a composition for a heat cycle system comprising trifluoroethylene (HFO-1123), which has a low global warming potential and excellent cycle performance of HFO-1123 and which has high durability, and a heat cycle system employing the composition, which has less influence over global warming and has both high cycle performance and durability.A composition for a heat cycle system, which comprises a working fluid for heat cycle containing trifluoroethylene, and a radical scavenger, and a heat cycle system employing the composition for a heat cycle system.

1 - 15 . (canceled) 
     
     
         16 : A composition for a heat cycle system, comprising a working fluid, wherein:
 the working fluid comprises:
 trifluoroethylene; and 
 a hydrofluoroolefin other than trifluoroethylene; 
   the working fluid does not exhibit a self-decomposition property;   presence or absence of the self-decomposition property is determined by:
 enclosing a sample of the working fluid and a platinum wire in a spherical pressure resistant reactor at a predetermined temperature and pressure selected from the group consisting of 40° C. and 0.98 MPaG, 100° C. and 0.90 MPaG, 100° C. and 0.80 MPaG, 140° C. and 0.70 MPaG, and 180° C. and 0.60 MPaG; 
 fusing the platinum wire by application of heat to ignite the working fluid; 
 measuring changes in temperature and pressure in the reactor after igniting the working fluid; and 
 analyzing a gas composition of the reactor after igniting the working fluid; 
   the self-decomposition property is present when a pressure increase and a temperature increase are measured, and a large amount of a self-decomposition reaction product is detected by the gas analysis, after igniting the working fluid at each predetermined temperature and pressure;   the platinum w % ire has an outer diameter of 0.5 mm and a length of 25 mm;   the spherical pressure resistant reactor has an internal capacity of 650 cm 3 ;   the platinum wire is heated by applying a voltage of 10 V at an electric current of 50 A; and   the self-decomposition reaction product comprises CF 4 , HF, and coke.   
     
     
         17 : The composition according to  claim 16 , comprising trifluoroethylene in an amount of at least 20 mass % based on a total mass of the working fluid. 
     
     
         18 : The composition according to  claim 16 , comprising trifluoroethylene in an amount of 20 to 80 mass % based on a total mass of the working fluid. 
     
     
         19 : The composition according to  claim 16 , wherein the hydrofluoroolefin other than trifluoroethylene comprises at least one selected from the group consisting of 2,3,3,3-tetrafluoropropene, 1,2-difluoroethylene, 2-fluoropropene, 1,1,2-trifluoropropene, trans-1,2,3,3,3-pentafluoropropene, cis-1,2,3,3,3-pentafluoropropene, trans-1,3,3,3-tetrafluoropropene, cis-1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene. 
     
     
         20 : The composition according to  claim 16 , wherein the hydrofluoroolefin other than trifluoroethylene comprises at least one selected from the group consisting of 2,3,3,3-tetrafluoropropene, trans-1,3,3,3-tetrafluoropropene, and cis-1,3,3,3-tetrafluoropropene. 
     
     
         21 : The composition according to  claim 16 , wherein the hydrofluoroolefin other than trifluoroethylene comprises at least one selected from the group consisting of 2,3,3,3-tetrafluoropropene and trans-1,3,3,3-tetrafluoropropene. 
     
     
         22 : The composition according to  claim 16 , wherein the hydrofluoroolefin other than trifluoroethylene comprises 2,3,3,3-tetrafluoropropene. 
     
     
         23 : The composition according to  claim 22 , comprising trifluoroethylene and 2,3,3,3-tetrafluoropropene in a total amount of 70 to 100 mass % based on a total mass of the working fluid. 
     
     
         24 : The composition according to  claim 22 , comprising 2,3,3,3-tetrafluoropropene in an amount of 5 to 65 mass % based on a total mass of trifluoroethylene and 2,3,3,3-tetrafluoropropene. 
     
     
         25 : The composition according to  claim 16 , wherein the working fluid comprises trifluoroethylene, difluoromethane, and 2,3,3,3-tetrafluoropropene. 
     
     
         26 : The composition according to  claim 25 , wherein:
 trifluoroethylene is present in an amount of 20 to 80 mass % based on a total mass of the working fluid;   difluoromethane is present in an amount of 15 to 75 mass % based on the total mass of the working fluid; and   2,3,3,3-tetrafluoropropene is present in an amount of 5 to 50 mass % based on the total mass of the working fluid.   
     
     
         27 : The composition according to  claim 16 , wherein the working fluid further comprises a hydrocarbon. 
     
     
         28 : The composition according to  claim 16 , wherein the working fluid further comprises propane.