Method for leak detection in heat transfer systems

A method for detecting a leak of heat transfer composition in a closed loop heat transfer system, comprising measuring the pressure of the heat transfer composition with a pressure measuring device disposed within said heat transfer system at a first time, and measuring the pressure of the heat transfer composition at a second time later than the first time, and comparing the pressure measured at the first time with the pressure measured at the second time, wherein a drop in pressure from the first time to the second time indicates a leak;

• wherein said heat transfer composition comprises at least one compound selected from the group consisting of hydrofluorocarbons, fluoroethers, fluoroolefins, hydrocarbons, CF3I, NH3, CO2, and mixtures thereof;
• provided that said heat transfer composition comprises at least one fluoroolefin selected from the group consisting of:
• (i) fluoroolefins of the formula E- or Z—R1CH═CHR2, wherein R1 and R2 are, independently, C1 to C6 perfluoroalkyl groups, and mixtures thereof;
• (ii) cyclic fluoroolefins of the formula cyclo-[CX=CY(CZW)n—], wherein X, Y, Z, and W, independently, are H or F, and n is an integer from 2 to 5, and mixtures thereof;
• and
• (iii) fluoroolefins selected from the group consisting of:
• 1 ,2,3,3,3-pentafluoro-1-propene (CHF═CFCF3), 1,1,3,3,3-pentafluoro-1-propene (CF2═CHCF3), 1,1,2,3,3-pentafluoro-1-propene (CF2═CFCHF2), 1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF2), 2,3,3,3-tetrafluoro-1-propene (CH2═CFCF3), 1,3,3,3-tetrafluoro-1-propene (CHF═CHCF3), 1,1,2,3-tetrafluoro-1-propene (CF2═CFCH2F), 1,1,3,3-tetrafluoro-1-propene (CF2═CHCHF2), 1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF2), 3,3,3-trifluoro-1-propene (CH2═CHCF3), 2,3,3-trifluoro-1-propene (CHF2CF═CH2);
• 1,1,2-trifluoro-1-propene (CH3CF═CF2);
• 1,2,3-trifluoro-1-propene (CH2FCF═CF2);
• 1,1,3-trifluoro-1-propene (CH2FCH═CF2);
• 1,3,3-trifluoro-1-propene (CHF2CH═CHF);
• 1,1,1,2,3,4,4,4-octafluoro-2-butene (CF3CF═CFCF3);
• 1,1,2,3,3,4,4,4-octafluoro-1-butene (CF3CF2CF═CF2);
• 1,1,1,2,4,4,4-heptafluoro-2-butene (CF3CF═CHCF3);
• 1,2,3,3,4,4,4-heptafluoro-1-butene (CHF═CFCF2CF3);
• 1,1,1,2,3,4,4-heptafluoro-2-butene (CHF2CF═CFCF3);
• 1,3,3,3-tetrafluoro-2-(trifluoromethyl)-1-propene ((CF3)2C═CHF);
• 1,1,3,3,4,4,4-heptafluoro-1-butene (CF2═CHCF2CF3);
• 1,1,2,3,4,4,4-heptafluoro-1-butene (CF2═CFCHFCF3);
• 1,1,2,3,3,4,4-heptafluoro-1-butene (CF2═CFCF2CHF2);
• 2,3,3,4,4,4-hexafluoro-1-butene (CF3CF2CF═CH2);
• 1,3,3,4,4,4-hexafluoro-1-butene (CHF═CHCF2CF3);
• 1,2,3,4,4,4-hexafluoro-1-butene (CHF═CFCHFCF3);
• 1,2,3,3,4,4-hexafluoro-1-butene (CHF═CFCF2CHF2);
• 1,1,2,3,4,4-hexafluoro-2-butene (CHF2CF═CFCHF2);
• 1,1,1,2,3,4-hexafluoro-2-butene (CH2FCF═CFCF3);
• 1,1,1,2,4,4-hexafluoro-2-butene (CHF2CH═CFCF3);
• 1,1,1,3,4,4-hexafluoro-2-butene (CF3CH═CFCHF2);
• 1,1,2,3,3,4-hexafluoro-1-butene (CF2═CFCF2CH2F);
• 1,1,2,3,4,4-hexafluoro-1-butene (CF2═CFCHFCHF2);
• 3,3,3-trifluoro-2-(trifluoromethyl)-1-propene (CH2═C(CF3)2);
• 1,1,1,2,4-pentafluoro-2-butene (CH2FCH═CFCF3);
• 1,1,1,3,4-pentafluoro-2-butene (CF3CH═CFCH2F);
• 3,3,4,4,4-pentafluoro-1-butene (CF3CF2CH═CH2);
• 1,1,1,4,4-pentafluoro-2-butene (CHF2CH═CHCF3);
• 1,1,1,2,3-pentafluoro-2-butene (CH3CF═CFCF3);
• 2,3,3,4,4-pentafluoro-1-butene (CH2═CFCF2CHF2);
• 1,1,2,4,4-pentafluoro-2-butene (CHF2CF═CHCHF2);
• 1,1,2,3,3-pentafluoro-1-butene (CH3CF2CF═CF2);
• 1,1,2,3,4-pentafluoro-2-butene (CH2FCF═CFCHF2);
• 1,1,3,3,3-pentafluoro-2-methyl-1-propene (CF2═C(CF3)(CH3));
• 2-(difluoromethyl)-3,3,3-trifluoro-1-propene (CH2═C(CHF2)(CF3));
• 2,3,4,4,4-pentafluoro-1-butene (CH2═CFCHFCF3);
• 1,2,4,4,4-pentafluoro-1-butene (CHF═CFCH2CF3);
• 1,3,4,4,4-pentafluoro-1-butene (CHF═CHCHFCF3);
• 1,3,3,4,4-pentafluoro-1-butene (CHF═CHCF2CHF2);
• 1,2,3,4,4-pentafluoro-1-butene (CHF═CFCHFCHF2);
• 3,3,4,4-tetrafluoro-1-butene (CH2═CHCF2CHF2);
• 1,1-difluoro-2-(difluoromethyl)-1-propene (CF2═C(CHF2)(CH3));
• 1,3,3,3-tetrafluoro-2-methyl-1-propene (CHF═C(CF3)(CH3));
• 3,3-difluoro-2-(difluoromethyl)-1-propene (CH2═C(CHF2)2);
• 1,1,1,2-tetrafluoro-2-butene (CF3CF═CHCH3);
• 1,1,1,3-tetrafluoro-2-butene (CH3CF═CHCF3);
• 1,1,1,2,3,4,4,5,5,5-decafluoro-2-pentene (CF3CF═CFCF2CF3);
• 1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene (CF2═CFCF2CF2CF3);
• 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene ((CF3)2C═CHCF3);
• 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene (CF3CF═CHCF2CF3);
• 1,1,1,3,4,4,5,5,5-nonafluoro-2-pentene (CF3CH═CFCF2CF3);
• 1,2,3,3,4,4,5,5,5-nonafluoro-1-pentene (CHF═CFCF2CF2CF3);
• 1,1,3,3,4,4,5,5,5-nonafluoro-1-pentene (CF2═CHCF2CF2CF3);
• 1,1,2,3,3,4,4,5,5-nonafluoro-1-pentene (CF2═CFCF2CF2CHF2);
• 1,1,2,3,4,4,5,5,5-nonafluoro-2-pentene (CHF2CF═CFCF2CF3);
• 1,1,1,2,3,4,4,5,5-nonafluoro-2-pentene (CF3CF═CFCF2CHF2);
• 1,1,1,2,3,4,5,5,5-nonafluoro-2-pentene (CF3CF═CFCHFCF3);
• 1,2,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene (CHF═CFCF(CF3)2);
• 1,1,2,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene (CF2═CFCH(CF3)2);
• 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene (CF3CH═C(CF3)2);
• 1,1,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene (CF2═CHCF(CF3)2);
• 2,3,3,4,4,5,5,5-octafluoro-1-pentene (CH2═CFCF2CF2CF3);
• 1,2,3,3,4,4,5,5-octafluoro-1-pentene (CHF═CFCF2CF2CHF2);
• 3,3,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene (CH2═C(CF3)CF2CF3);
• 1,1,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene (CF2═CHCH(CF3)2);
• 1,3,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene (CHF═CHCF(CF3)2);
• 1,1,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene (CF2═C(CF3)CH2CF3);
• 3,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene ((CF3)2CFCH═CH2);
• 3,3,4,4,5,5,5-heptafluoro-1-pentene (CF3CF2CF2CH═CH2);
• 2,3,3,4,4,5,5-heptafluoro-1-pentene (CH2═CFCF2CF2CHF2);
• 1,1,3,3,5,5,5-heptafluoro-1-butene (CF2═CHCF2CH2CF3);
• 1,1,1,2,4,4,4-heptafluoro-3-methyl-2-butene (CF3CF═C(CF3)(CH3));
• 2,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene (CH2═CFCH(CF3)2);
• 1,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene (CHF═CHCH(CF3)2);
• 1,1,1,4-tetrafluoro-2-(trifluoromethyl)-2-butene (CH2FCH═C(CF3)2);
• 1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-butene (CH3CF═C(CF3)2);
• 1,1,1-trifluoro-2-(trifluoromethyl)-2-butene ((CF3)2C═CHCH3);
• 3,4,4,5,5,5-hexafluoro-2-pentene (CF3CF2CF═CHCH3);
• 1,1,1,4,4,4-hexafluoro-2-methyl-2-butene (CF3C(CH3)═CHCF3);
• 3,3,4,5,5,5-hexafluoro-1-pentene (CH2═CHCF2CHFCF3);
• 4,4,4-trifluoro-2-(trifluoromethyl)-1-butene (CH2═C(CF3)CH2CF3);
• 1,1,2,3,3,4,4,5,5,6,6,6-dodecafluoro-1-hexene (CF3(CF2)3CF═CF2);
• 1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3-hexene (CF3CF2CF═CFCF2CF3);
• 1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene ((CF3)2C═C(CF3)2);
• 1,1,1,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)-2-pentene ((CF3)2CFCF═CFCF3);
• 1,1,1,4,4,5,5,5-octafluoro-2-(trifluoromethyl)-2-pentene ((CF3)2C═CHC2F5);
• 1,1,1,3,4,5,5,5-octafluoro-4-(trifluoromethyl)-2-pentene ((CF3)2CFCF═CHCF3);
• 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene (CF3CF2CF2CF2CH═CH2);
• 4,4,4-trifluoro-3,3-bis(trifluoromethyl)-1-butene (CH2═CHC(CF3)3);
• 1,1,1,4,4,4-hexafluoro-3-methyl-2-(trifluoromethyl)-2-butene ((CF3)2C═C(CH3)(CF3));
• 2,3,3,5,5,5-hexafluoro-4-(trifluoromethyl)-1-pentene (CH2═CFCF2CH(CF3)2);
• 1,1,1,2,4,4,5,5,5-nonafluoro-3-methyl-2-pentene (CF3CF═C(CH3)CF2CF3);
• 1,1,1,5,5,5-hexafluoro-4-(trifluoromethyl)-2-pentene (CF3CH═CHCH(CF3)2);
• 3,4,4,5,5,6,6,6-octafluoro-2-hexene (CF3CF2CF2CF═CHCH3);
• 3,3,4,4,5,5,6,6-octafluorol-hexene (CH2═CHCF2CF2CF2CHF2);
• 1,1,1,4,4-pentafluoro-2-(trifluoromethyl)-2-pentene ((CF3)2C═CHCF2CH3);
• 4,4,5,5,5-pentafluoro-2-(trifluoromethyl)-1-pentene (CH2═C(CF3)CH2C2F5);
• 3,3,4,4,5,5,5-heptafluoro-2-methyl-1-pentene (CF3CF2CF2C(CH3)═CH2);
• 4,4,5,5,6,6,6-heptafluoro-2-hexene (CF3CF2CF2CH═CHCH3);
• 4,4,5,5,6,6,6-heptafluoro-1-hexene (CH2═CHCH2CF2C2F5);
• 1,1,1,2,2,3,4-heptafluoro-3-hexene (CF3CF2CF═CFC2H5);
• 4,5,5,5-tetrafluoro-4-(trifluoromethyl)-1-pentene (CH2═CHCH2CF(CF3)2);
• 1,1,1,2,5,5,5-heptafluoro-4-methyl-2-pentene (CF3CF═C NCH (CF3)(CH3));
• 1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-pentene ((CF3)2C═CFC2H5);
• 1,1,1,2,3,4,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene (CF3CF═CFCF2CF2C2F5);
• 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene (CF3CF2CF═CFCF2C2F5);
• 1,1,1,3,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene (CF3CH═CFCF2CF2C2F5);
• 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene (CF3CF═CHCF2CF2C2F5);
• 1,1,1,2,2,4,5,5,6,6,7,7,7-tridecafluoro-3-heptene (CF3CF2CH═CFCF2C2F5);
• 1,1,1,2,2,3,5,5,6,6,7,7,7-tridecafluoro-3-heptene (CF3CF2CF═CHCF2C2F5);
• pentafluoroethyl trifluorovinyl ether (CF2═CFOCF2CF3);
• and trifluoromethyl trifluorovinyl ether (CF2═CFOCF3);
• and mixtures thereof;
• and wherein said fluoroolefin can be any mixture of any compounds from (i), (ii), and (iii) above.