Heat transfer process
The use of a refrigerant in organic Rankine cycle systems including at least one hydrofluoroolefin, having at least four carbon atoms represented by the formula (I) R1CH═CHR2 in which R1 and R2 independently represent alkyl groups having from 1 to 6 carbon atoms, substituted with at least one fluorine atom, optionally with at least one chlorine atom.
1. An energy conversion process employing a turbine system having at least one stage comprising successively:
evaporating a refrigerant,
expanding said refrigerant in a turbine,
desuperheating said refrigerant in an internal exchanger,
condensing said refrigerant, and
compressing said refrigerant in a pump,
wherein the refrigerant comprises:
from 40 to 100 wt. % of 1,1,1,4,4,4-hexafluorobut-2-ene, and
from 0 to 60 wt. % of at least one compound selected from the group consisting of pentane, isopentane, cyclopentane and trans-1,2-dichloroethylene.
2. The process as claimed in claim 1 , wherein the evaporation temperature is between 60 and 150° C.
3. The process as claimed in claim 1 , wherein the refrigerant further comprises at least one compound selected from hydrofluorocarbons, hydrocarbons, (hydro)fluoroethers, hydrochlorofluoropropenes, hydrofluoropropenes, ethers, methyl formate, carbon dioxide and trans-1,2-dichloroethylene.
4. The process as claimed in claim 1 , wherein the refrigerant further comprises at least one hydrofluorocarbon selected from 1,1,3,3,3-pentafluoropropane and 1,1,3,3,3-pentafluorobutane.
5. The process as claimed in claim 1 , wherein the refrigerant comprises pentane.
6. The process as claimed in claim 1 , wherein the refrigerant consists of from 40 to 100 wt. % of 1,1,1,4,4,4-hexafluorobut-2-ene and from 0 to 60 wt. % of at least one compound selected from pentane, isopentane, cyclopentane and trans-1,2-dichloroethylene, and optionally a lubricant, and optionally a stablizer.
7. The process as claimed in claim 1 , wherein the refrigerant comprises from 60 to 100 wt. % of 1,1,1,4,4,4-hexafluorobut-2-ene and from 0 to 40 wt. % of cyclopentane, pentane, isopentane or trans-1,2-dichloroethylene.
8. The process as claimed in claim 1 , wherein the refrigerant comprises a stabilizer.
9. The process as claimed in claim 1 , wherein the refrigerant comprises a lubricant.
10. The process as claimed in claim 9 , wherein the lubricant is polyalkylene glycol, polyol ester or polyvinyl ether.
11. The process as claimed in claim 1 , wherein the evaporation temperature is between 80 and 150° C.
12. The process as claimed in claim 1 , wherein the energy conversion process is an organic Rankine cycle.
13. The process as claimed in claim 12 , wherein the refrigerant comprises a lubricant.
14. The process as claimed in claim 13 , wherein the evaporation temperature is between 60 and 150° C.