Working medium for heat pump, and heat pump system

1. A working medium for a heat pump, comprising:

1,1,2-trifluoroethylene;

at least one of 1,1,1,2-tetrafluoroethane and pentafluoroethane; and

at least one of 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene.

2. The working medium of claim 1 , which satisfies the formulae (1) to (3):

60≦ a≦ 80  (1)

b+c≧ 5  (2)

a+b+c+d≧ 90  (3)

wherein a is a content of 1,1,2-trifluoroethylene in mass %, b is a content of 1,1,1,2-tetrafluoroethane in mass %, c is a content of pentafluoroethane in mass %, and d is a total content of 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene in mass %.

3. The working medium of claim 1 , which satisfies the formula (4):

14.3× b+ 35× c< 500  (4)

wherein b is a content of 1,1,1,2-tetrafluoroehtane in mass %, and c is a content of pentafluoroethane in mass %.

4. The working medium of claim 1 , wherein a total content of 1,1,1,2-tetrafluoroethane and pentafluoroethane is at most 35 mass %.

5. The working medium of claim 1 , wherein a total content of 1,1,1,2-tetrafluoroethane and pentafluoroethane is at most 20 mass %.

6. The working medium of claim 1 , wherein a total content of 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene is at least 1 mass %.

7. The working medium of claim 1 , wherein a total content of 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene is at most 35 mass %.

8. The working medium of claim 1 , wherein a total content of 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene is from 5 to 35 mass %.

9. A heat pump system, comprising:

the working medium of claim 1 .

10. The heat pump system of claim 9 , which is an air-conditioning system.

11. The heat pump system of claim 9 , which is a refrigerating system.

12. The working medium of claim 1 ,

wherein a content of 1,1,2-trifluoroethylene is from 60 to 80 mass %,

a total content of 1,1,1,2-tetrafluoroethane and pentafluoroethane is from 5 to 35 mass %, and

a total content of 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene is from 5 to 35 mass %.

13. The working medium of claim 3 ,

wherein a content of 1,1,2-trifluoroethylene is from 60 to 80 mass %,

a total content of 1,1,1,2-tetrafluoroethane and pentafluoroethane is from 5 to 35 mass %, and

a total content of 2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, and 3,3,3-trifluoropropene is from 5 to 35 mass %.

14. The working medium of claim 1 , further comprising:

at least one hydrofluoroolefin selected from the group consisting of 1,2-difluoroethylene, 2-fluoropropene, 1,1,2-trifluoropropene, and 1,2,3,3,3-pentafluoropropene.

15. The working medium of claim 1 , further comprising:

at least one hydrofluorocarbon selected from the group consisting of difluoromethane, difluoroethane, trifluoroethane, tetrafluoroethane other than 1,1,1,2-tetrafluoroethane, pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane, and heptafluorocyclopentane.

16. The working medium of claim 1 , further comprising:

at least one hydrocarbon selected from the group consisting of propane, propylene, cyclopropane, butane, isobutane, pentane, and isopentane.

17. The working medium of claim 1 , further comprising:

at least one hydrochlorofluoroolefin selected from the group consisting of 1-chloro-2,3,3,3-tetrafluoropropene and 1-chloro-1,2-difluoroethylene.

18. The working medium of claim 1 , further comprising:

at least one chlorofluoroolefin selected from the group consisting of 1,1-dichloro-2,3,3,3-tetrafluoropropene and 1,2-dichloro-1,2-difluoroethylene.

19. The working medium of claim 1 , wherein the working medium comprises 1,1,2-trifluoroethylene, pentafluoroethane, and 2,3,3,3-tetrafluoropropene.

20. The working medium of claim 1 , wherein the working medium comprises 1,1,2-trifluoroethylene, 1,1,1,2-tetrafluoroethane, and 1,3,3,3-tetrafluoropropene.