Method for producing working fluid

1. A method for producing a working fluid containing trifluoroethylene in a proportion of at most 70 mol % based on the entire amount, which comprises mixing a first component containing trifluoroethylene in a proportion of higher than 70 mol % stored in a first container, and a second component having no self-decomposition property containing at least one member selected from a saturated hydrofluorocarbon, an unsaturated hydrofluorocarbon, an unsaturated hydrochlorofluorocarbon and an unsaturated chlorofluorocarbon in a proportion of at least 30 mol %, stored in a second container, by the following step (A), (B) or (C):

(A) the first component is supplied to the second container under the following condition (1) or (2):

(1) the temperature (t1) of the first component at the time of the supply is t1<0.5° C., and at least during the period from the start of the supply to the completion of mixing, the relation between the gauge pressure (P2) in the second container and the gauge pressure (p1) of the first component at the time of the supply is kept to be p1>P2, and the temperature (T2) in the second container is kept to be in a state of T2<0.5° C.;

(2) the first component at the time of the supply is in a gaseous state with its temperature (t1) of 0.5° C.≤t1≤180° C. and its gauge pressure (p1) of p1[MPa]<1.05−0.0025t1, and at least during the period from the start of the supply to the completion of mixing, the relation between the gauge pressure (P2) in the second container and the gauge pressure (p1) of the first component is kept to be p1>P2, and the temperature (T2) in the second container is kept to be in a state of T2≤180° C. and T2<(1.05−p1)/0.0025;

(B) the second component is supplied to the first container under the following conditions (3) and (4):

(3) at least during the period from the start of the supply to the completion of mixing, the temperature (T1) and the gauge pressure (P1) in the first container are kept to be in a state of T1<0.5° C. or in a state of 0.5° C.≤T1≤180° C. and P1[MPa]<1.05−0.0025T1,

(4) the gauge pressure (p2) of the second component is p2>P1 at least at the time of the supply:

(C) to a separate third container, while at least during the period from the start of the following supply to the completion of mixing, the temperature (T3) and the gauge pressure (P3) in the third container are kept to be in a state of T3<0.5° C. or in a state of 0.5° C.≤T3≤180° C. and P3[MPa]<1.05−0.0025T3, the first component is supplied under the following condition (5) or (6), and the second component is supplied while at least at the time of the supply, its gauge pressure (p2) is kept to be p2>P3:

(5) the temperature (t1) of the first component at the time of the supply is t1<0.5° C., and at least during the period from the start of the supply to the completion of mixing, the relation between the gauge pressure (P3) in the third container and the gauge pressure (p1) of the first component at the time of the supply is kept to be p1>P3, and the temperature (T3) in the third container is kept to be in a state of T3<0.5° C.;

(6) the first component at the time of the supply is in a gaseous state with its temperature (t1) of 0.5° C.≤T1≤180° C. and its gauge pressure (p1) of p1[MPa]<1.05−0.0025t1, and at least during the period from the start of the supply to the completion of mixing, the relation between the gauge pressure (P3) in the third container and the gauge pressure (p1) of the first component is kept to be p1>P3, and the temperature (T3) in the third container is kept to be in a state of T3≤180° C. and T3<(1.05−p1)/0.0025.

2. The method for producing a working fluid according to claim 1 , wherein in the step (A), both the temperature in the first container and the temperature in the second container are kept to be less than 0.5° C., and the first component in a liquid state with t1<0.5° C. is supplied to the second container.

3. The method for producing a working fluid according to claim 1 , wherein in the step (B), both the temperature in the first container and the temperature in the second container are kept to be less than 0.5° C., and the second component in a liquid state with t2<0.5° C. is supplied to the first container.

4. The method for producing a working fluid according to claim 1 , wherein in the step (C), all of the temperature in the first container, the temperature in the second container and the temperature in the third container are kept to be less than 0.5° C., and the first component in a liquid state with t1<0.5° C. and the second component in a liquid state with t2<0.5° C. are respectively supplied to the third container.

5. The method for producing a working fluid according to claim 1 , wherein the second component is 2,3,3,3-tetrafluoropropene and/or difluoromethane.

6. The method for producing a working fluid according to claim 1 , wherein the working fluid obtained by mixing the first component and the second component is a working fluid containing trifluoroethylene and 2,3,3,3-tetrafluoropropene, the proportion of the total amount of trifluoroethylene and 2,3,3,3-tetrafluoropropene based on the entire amount of the working fluid is from 70 to 100 mass %, and based on the total amount of trifluoroethylene and 2,3,3,3-tetrafluoropropene, the proportion of trifluoroethylene is at least 35 mass % and at most 70 mass %.

7. The method for producing a working fluid according to claim 6 , wherein the first component is trifluoroethylene.

8. The method for producing a working fluid according to claim 1 , wherein the working fluid obtained by mixing the first component and the second component is a working fluid containing trifluoroethylene and difluoromethane, the proportion of the total amount of trifluoroethylene and difluoromethane based on the entire amount of the working fluid is from 70 to 100 mass %, and based on the total amount of trifluoroethylene and difluoromethane, the proportion of trifluoroethylene is at least 35 mass % and at most 70 mass %.

9. The method for producing a working fluid according to claim 1 , wherein the working fluid obtained by mixing the first component and the second component is a working fluid containing trifluoroethylene, 2,3,3,3-tetrafluoropropene and difluoromethane, the proportion of the total amount of trifluoroethylene, 2,3,3,3-tetrafluoropropene and difluoromethane based on the entire amount of the working fluid is from 70 to 100 mass %, and based on the total amount of trifluoroethylene, 2,3,3,3-tetrafluoropropene and difluoromethane, the proportion of trifluoroethylene is at least 10 mass % and at most 70 mass %, the proportion of 2,3,3,3-tetrafluoropropene is at most 50 mass %, and the proportion of difluoromethane is at most 75 mass %.

10. The method for producing a working fluid according to claim 9 , wherein the second component is a mixture of 2,3,3,3-tetrafluoropropene and difluoromethane.

11. The method for producing a working fluid according to claim 1 , wherein the second component is trans-1,3,3,3-tetrafluoropropene.

12. The method for producing a working fluid according to claim 1 , wherein the second component is a mixture of trans-1,3,3,3-tetrafluoropropene and difluoromethane.