Method for exchanging heat in vapor compression heat transfer systems

Abstract

A multi-step method is disclosed for exchanging heat in a vapor compression heat transfer system having a working fluid circulating therethrough. The method includes the step of circulating a working fluid comprising a fluoroolefin to an inlet of a first tube of an internal heat exchanger, through the internal heat exchanger and to an outlet thereof. Also disclosed are vapor compression heat transfer systems for exchanging heat. The systems include an evaporator, a compressor, a dual-row condenser and an intermediate heat exchanger having a first tube and a second tube. A disclosed system involves a dual-row condenser connected to the first and second intermediate heat exchanger tubes. Another disclosed system involves a dual-row evaporator connected to the first and second intermediate heat exchanger tubes.

1 . A method for exchanging heat in a vapor compression heat transfer system having a working fluid circulating therethrough, comprising the steps of:
 (a) circulating a working fluid comprising a fluoroolefin to an inlet of a first tube of an internal heat exchanger, through the internal heat exchanger and to an outlet thereof;   (b circulating the working fluid from the outlet of the first tube of the internal heat exchanger to an inlet of an evaporator, through the evaporator to evaporate the working fluid and convert it into a gas, and through an outlet of the evaporator;   (c) circulating the working fluid from the outlet of the evaporator to an inlet of a second tube of the internal heat exchanger to transfer heat from the liquid working fluid from the condenser to the gaseous working fluid from the evaporator, through the internal heat exchanger, and to an outlet of the second tube;   (d) circulating the working fluid from the outlet of the second tube of the internal heat exchanger to an inlet of a compressor, through the compressor to compress the working fluid gas, and to an outlet of the compressor;   (e) circulating the working fluid from the outlet of the compressor to an inlet of a condenser and through the condenser to condense the compressed working fluid gas into a liquid, and to an outlet of the condenser;   (f) circulating the working fluid from the outlet of the condenser to an inlet of the first tube of the intermediate heat exchanger to transfer heat from the liquid from the condenser to the gas from the evaporator, and to an outlet of the second tube; and   (g) circulating the working fluid from the outlet of the second tube of the internal heat exchanger back to the evaporator.   
     
     
         2 . The method of  claim 1 , where the fluoroolefin is at least one compound selected from the group consisting of:
 (i) fluoroolefins of the formula E- or Z—R 1 CH═CHR 2 , wherein R 1  and R 2  are, independently, C 1  to C 6  perfluoroalkyl groups;   (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   (iii) fluoroolefins selected from the group consisting of: 1,2,3,3,3-pentafluoro-1-propene (CHF═CFCF 3 ), 1,1,3,3,3-pentafluoro-1-propene (CF 2 ═CHCF 3 ), 1,1,2,3,3-pentafluoro-1-propene (CF 2 ═CFCHF 2 ), 1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF 2 ), 2,3,3,3-tetrafluoro-1-propene (CH 2 ═CFCF 3 ), 1,3,3,3-tetrafluoro-1-propeneCHF═CHCF 3 ), 1,1,2,3-tetrafluoro-1-propene (CF 2 ═CFCH 2 F), 1,1,3,3-tetrafluoro-1-propene (CF 2 ═CHCHF 2 ), 1,2,3,3-tetrafluoro-1-propene (CHF═CFCHF 2 ), 3,3,3-trifluoro-1-propene (CH 2 ═CHCF 3 ), 2,3,3-trifluoro-1-propene (CHF 2 CF═CH 2 ); 1,1,2-trifluoro-1-propene (CH 3 CF═CF 2 ); 1,2,3-trifluoro-1-propene (CH 2 FCF═CF 2 ); 1,1,3-trifluoro-1-propene (CH 2 FCH═CF 2 ); 1,3,3-trifluoro-1-propene (CHF 2 CH═CHF); 1,1,1,2,3,4,4,4-octafluoro-2-butene (CF 3 CF═CFCF 3 ); 1,1,2,3,3,4,4,4-octafluoro-1-butene (CF 3 CF 2 CF═CF 2 ); 1,1,1,2,4,4,4-heptafluoro-2-butene (CF 3 CF═CHCF 3 ); 1,2,3,3,4,4,4-heptafluoro-1-butene (CHF═CFCF 2 CF 3 ); 1,1,1,2,3,4,4-heptafluoro-2-butene (CHF 2 CF═CFCF 3 ); 1,3,3,3-tetrafluoro-2-(trifluoromethyl)-1-propene ((CF 3 ) 2 C═CHF); 1,1,3,3,4,4,4-heptafluoro-1-butene (CF 2 ═CHCF 2 CF 3 ); 1,1,2,3,4,4,4-heptafluoro-1-butene (CF 2 ═CFCHFCF 3 ); 1,1,2,3,3,4,4-heptafluoro-1-butene (CF 2 ═CFCF 2 CHF 2 ); 2,3,3,4,4,4-hexafluoro-1-butene (CF 3 CF 2 CF═CH 2 ); 1,3,3,4,4,4-hexafluoro-1-butene (CHF═CHCF 2 CF 3 ); 1,2,3,4,4,4-hexafluoro-1-butene (CHF═CFCHFCF 3 ); 1,2,3,3,4,4-hexafluoro-1-butene (CHF═CFCF 2 CHF 2 ); 1,1,2,3,4,4-hexafluoro-2-butene (CHF 2 CF═CFCHF 2 ); 1,1,1,2,3,4-hexafluoro-2-butene (CH 2 FCF═CFCF 3 ); 1,1,1,2,4,4-hexafluoro-2-butene (CHF 2 CH═CFCF 3 ); 1,1,1,3,4,4-hexafluoro-2-butene (CF 3 CH═CFCHF 2 ); 1,1,2,3,3,4-hexafluoro-1-butene (CF 2 ═CFCF 2 CH 2 F); 1,1,2,3,4,4-hexafluoro-1-butene (CF 2 ═CFCHFCHF 2 ); 3,3,3-trifluoro-2-(trifluoromethyl)-1-propene (CH 2 ═C(CF 3 ) 2 ); 1,1,1,2,4-pentafluoro-2-butene (CH 2 FCH═CFCF 3 ); 1,1,1,3,4-pentafluoro-2-butene (CF 3 CH═CFCH 2 F); 3,3,4,4,4-pentafluoro-1-butene (CF 3 CF 2 CH═CH 2 ); 1,1,1,4,4-pentafluoro-2-butene (CHF 2 CH═CHCF 3 ); 1,1,1,2,3-pentafluoro-2-butene (CH 3 CF═CFCF 3 ); 2,3,3,4,4-pentafluoro-1-butene (CH 2 ═CFCF 2 CHF 2 ); 1,1,2,4,4-pentafluoro-2-butene (CHF 2 CF═CHCHF 2 ); 1,1,2,3,3-pentafluoro-1-butene (CH 3 CF 2 CF═CF 2 ); 1,1,2,3,4-pentafluoro-2-butene (CH 2 FCF═CFCHF 2 ); 1,1,3,3,3-pentafluoro-2-methyl-1-propene (CF 2 ═C(CF 3 )(CH 3 )); 2-(difluoromethyl)-3,3,3-trifluoro-1-propene (CH 2 ═C(CHF 2 )(CF 3 )); 2,3,4,4,4-pentafluoro-1-butene (CH 2 ═CFCHFCF 3 ); 1,2,4,4,4-pentafluoro-1-butene (CHF═CFCH 2 CF 3 ); 1,3,4,4,4-pentafluoro-1-butene (CHF═CHCHFCF 3 ); 1,3,3,4,4-pentafluoro-1-butene (CHF═CHCF 2 CHF 2 ); 1,2,3,4,4-pentafluoro-1-butene (CHF═CFCHFCHF 2 ); 3,3,4,4-tetrafluoro-1-butene (CH 2 ═CHCF 2 CHF 2 ); 1,1-difluoro-2-(difluoromethyl)-1-propene (CF 2 ═C(CHF 2 )(CH 3 )); 1,3,3,3-tetrafluoro-2-methyl-1-propene (CHF═C(CF 3 )(CH 3 )); 3,3-difluoro-2-(difluoromethyl)-1-propene (CH 2 ═C(CHF 2 ) 2 ); 1,1,1,2-tetrafluoro-2-butene (CF 3 CF═CHCH 3 ); 1,1,1,3-tetrafluoro-2-butene (CH 3 CF═CHCF 3 ); 1,1,1,2,3,4,4,5,5,5-decafluoro-2-pentene (CF 3 CF═CFCF 2 CF 3 ); 1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene (CF 2 ═CFCF 2 CF 2 CF 3 ); 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene ((CF 3 ) 2 C═CHCF 3 ); 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene (CF 3 CF═CHCF 2 CF 3 ); 1,1,1,3,4,4,5,5,5-nonafluoro-2-pentene (CF 3 CH═CFCF 2 CF 3 ); 1,2,3,3,4,4,5,5,5-nonafluoro-1-pentene (CHF═CFCF 2 CF 2 CF 3 ); 1,1,3,3,4,4,5,5,5-nonafluoro-1-pentene (CF 2 ═CHCF 2 CF 2 CF 3 ); 1,1,2,3,3,4,4,5,5-nonafluoro-1-pentene (CF 2 ═CFCF 2 CF 2 CHF 2 ); 1,1,2,3,4,4,5,5,5-nonafluoro-2-pentene (CHF 2 CF═CFCF 2 CF 3 ); 1,1,1,2,3,4,4,5,5-nonafluoro-2-pentene (CF 3 CF═CFCF 2 CHF 2 ); 1,1,1,2,3,4,5,5,5-nonafluoro-2-pentene (CF 3 CF═CFCHFCF 3 ); 1,2,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene (CHF═CFCF(CF 3 ) 2 ); 1,1,2,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene (CF 2 ═CFCH(CF 3 ) 2 ); 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene (CF 3 CH═C(CF 3 ) 2 ); 1,1,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene (CF 2 ═CHCF(CF 3 ) 2 ); 2,3,3,4,4,5,5,5-octafluoro-1-pentene (CH 2 ═CFCF 2 CF 2 CF 3 ); 1,2,3,3,4,4,5,5-octafluoro-1-pentene (CHF═CFCF 2 CF 2 CHF 2 ); 3,3,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene (CH 2 ═C(CF 3 )CF 2 CF 3 ); 1,1,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene (CF 2 ═CHCH(CF 3 ) 2 ); 1,3,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene (CHF═CHCF(CF 3 ) 2 ); 1,1,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene (CF 2 ═C(CF 3 )CH 2 CF 3 ); 3,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene ((CF 3 ) 2 CFCH═CH 2 ); 3,3,4,4,5,5,5-heptafluoro-1-pentene (CF 3 CF 2 CF 2 CH═CH 2 ); 2,3,3,4,4,5,5-heptafluoro-1-pentene (CH 2 ═CFCF 2 CF 2 CHF 2 ); 1,1,3,3,5,5,5-heptafluoro-1-butene (CF 2 ═CHCF 2 CH 2 CF 3 ); 1,1,1,2,4,4,4-heptafluoro-3-methyl-2-butene (CF 3 CF═C(CF 3 )(CH 3 )); 2,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene (CH 2 ═CFCH(CF 3 ) 2 ); 1,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene (CHF═CHCH(CF 3 ) 2 ); 1,1,1,4-tetrafluoro-2-(trifluoromethyl)-2-butene (CH 2 FCH═C(CF 3 ) 2 ); 1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-butene (CH 3 CF═C(CF 3 ) 2 ); 1,1,1-trifluoro-2-(trifluoromethyl)-2-butene ((CF 3 ) 2 C═CHCH 3 ); 3,4,4,5,5,5-hexafluoro-2-pentene (CF 3 CF 2 CF═CHCH 3 ); 1,1,1,4,4,4-hexafluoro-2-methyl-2-butene (CF 3 C(CH 3 )═CHCF 3 ); 3,3,4,5,5,5-hexafluoro-1-pentene (CH 2 ═CHCF 2 CHFCF 3 ); 4,4,4-trifluoro-2-(trifluoromethyl)-1-butene (CH 2 ═C(CF 3 )CH 2 CF 3 ); 1,1,2,3,3,4,4,5,5,6,6,6-dodecafluoro-1-hexene (CF 3 (CF 2 ) 3 CF═CF 2 ); 1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3-hexene (CF 3 CF 2 CF═CFCF 2 CF 3 ); 1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene ((CF 3 ) 2 C═C(CF 3 ) 2 ); 1,1,1,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)-2-pentene ((CF 3 ) 2 CFCF═CFCF 3 ); 1,1,1,4,4,5,5,5-octafluoro-2-(trifluoromethyl)-2-pentene ((CF 3 ) 2 C═CHC 2 F 5 ); 1,1,1,3,4,5,5,5-octafluoro-4-(trifluoromethyl)-2-pentene ((CF 3 ) 2 CFCF═CHCF 3 ); 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene (CF 3 CF 2 CF 2 CF 2 CH═CH 2 ); 4,4,4-trifluoro-3,3-bis(trifluoromethyl)-1-butene (CH 2 ═CHC(CF 3 ) 3 ); 1,1,1,4,4,4-hexafluoro-3-methyl-2-(trifluoromethyl)-2-butene ((CF 3 ) 2 C═C(CH 3 )(CF 3 )); 2,3,3,5,5,5-hexafluoro-4-(trifluoromethyl)-1-pentene (CH 2 ═CFCF 2 CH(CF 3 ) 2 ); 1,1,1,2,4,4,5,5,5-nonafluoro-3-methyl-2-pentene (CF 3 CF═C(CH 3 )CF 2 CF 3 ); 1,1,1,5,5,5-hexafluoro-4-(trifluoromethyl)-2-pentene (CF 3 CH═CHCH(CF 3 ) 2 ); 3,4,4,5,5,6,6,6-octafluoro-2-hexene (CF 3 CF 2 CF 2 CF═CHCH 3 ); 3,3,4,4,5,5,6,6-octafluoro1-hexene (CH 2 ═CHCF 2 CF 2 CF 2 CHF 2 ); 1,1,1,4,4-pentafluoro-2-(trifluoromethyl)-2-pentene ((CF 3 ) 2 C═CHCF 2 CH 3 ); 4,4,5,5,5-pentafluoro-2-(trifluoromethyl)-1-pentene (CH 2 ═C(CF 3 )CH 2 C 2 F 5 ); 3,3,4,4,5,5,5-heptafluoro-2-methyl-1-pentene (CF 3 CF 2 CF 2 C(CH 3 )═CH 2 ); 4,4,5,5,6,6,6-heptafluoro-2-hexene (CF 3 CF 2 CF 2 CH═CHCH 3 ); 4,4,5,5,6,6,6-heptafluoro-1-hexene (CH 2 ═CHCH 2 CF 2 C 2 F 5 ); 1,1,1,2,2,3,4-heptafluoro-3-hexene (CF 3 CF 2 CF═CFC 2 H 5 ); 4,5,5,5-tetrafluoro-4-(trifluoromethyl)-1-pentene (CH 2 ═CHCH 2 CF(CF 3 ) 2 ); 1,1,1,2,5,5,5-heptafluoro-4-methyl-2-pentene (CF 3 CF═CHCH(CF 3 )(CH 3 )); 1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-pentene ((CF 3 ) 2 C═CFC 2 H 5 ); 1,1,1,2,3,4,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene (CF 3 CF═CFCF 2 CF 2 C 2 F 5 ); 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene (CF 3 CF 2 CF═CFCF 2 C 2 F 5 ); 1,1,1,3,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene (CF 3 CH═CFCF 2 CF 2 C 2 F 5 ); 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene (CF 3 CF═CHCF 2 CF 2 C 2 F 5 ); 1,1,1,2,2,4,5,5,6,6,7,7,7-tridecafluoro-3-heptene (CF 3 CF 2 CH═CFCF 2 C 2 F 5 ); 1,1,1,2,2,3,5,5,6,6,7,7,7-tridecafluoro-3-heptene (CF 3 CF 2 CF═CHCF 2 C 2 F 5 ); pentafluoroethyl trifluorovinyl ether (CF 2 ═CFOCF 2 CF 3 ); and trifluoromethyl trifluorovinyl ether (CF 2 ═CFOCF 3 ).   
     
     
         3 . The method of  claim 1 , where the working fluid in the second tube flows in a countercurrent direction to the direction of flow of the working fluid in the first tube, thereby cooling the working fluid in the first tube and heating the working fluid in the second tube. 
     
     
         4 . The method of  claim 1 , where the first tube has a larger diameter than the second tube, and the second tube is disposed concentrically in the first tube, and a hot liquid in the first tube surrounds a cool gas in the second tube. 
     
     
         5 . The method of  claim 1 , wherein the condensing step comprises:
 (i) circulating the working fluid to a back row of a dual-row condenser, where the back row receives the working fluid at a first temperature; and   (ii) circulating the working fluid to a front row of the dual-row condenser, where the front row receives the working fluid at a second temperature, where the second temperature is less than the first temperature, so that air which travels across the front row and the back row is preheated, whereby the temperature of the air is greater when it reaches the back row than when it reaches the front row.   
     
     
         6 . The method of  claim 1 , wherein the evaporating step comprises:
 (i) passing the working fluid through an inlet of a dual-row evaporator having a first row and a second row,   (ii) circulating the working fluid in the first row in a direction perpendicular to the flow of fluid through the inlet of the evaporator, and   (iii) circulating the working fluid in the second row in a direction generally counter to the direction of the flow of the working fluid through the inlet.   
     
     
         7 . The method of  claim 1 , wherein the working fluid further comprises at least one compound selected from hydrofluorocarbons, fluoroethers, hydrocarbons, dimethyl ether (DME), carbon dioxide (CO 2 ), ammonia (NH 3 ), and iodotrifluoromethane (CF 3 I). 
     
     
         8 . The method of  claim 5 , wherein the working fluid further comprises at least one compound selected from hydrofluorocarbons, fluoroethers, hydrocarbons, dimethyl ether (DME), carbon dioxide (CO 2 ), ammonia (NH 3 ), and iodotrifluoromethane (CF 3 I). 
     
     
         9 . The method of  claim 6 , wherein the working fluid further comprises at least one compound selected from hydrofluorocarbons, fluoroethers, hydrocarbons, dimethyl ether (DME), carbon dioxide (CO 2 ), ammonia (NH 3 ), and iodotrifluoromethane (CF 3 I). 
     
     
         10 . The method of  claims 1 , wherein the fluoroolefin comprises HFC-1234yf. 
     
     
         11 . The method of  claims 5 , wherein the fluoroolefin comprises HFC-1234yf. 
     
     
         12 . The method of  claims 6 , wherein the fluoroolefin comprises HFC-1234yf. 
     
     
         13 . The method of  claim 10 , wherein the coefficient of performance and the cooling capacity of the system is increased by at least 7.5% as compared to a system which uses HFC-134a as the working fluid. 
     
     
         14 . The method of  claim 11 , wherein the coefficient of performance and the cooling capacity of the system is increased by at least 7.5% as compared to a system which uses HFC-134a as the working fluid. 
     
     
         15 . The method of  claim 12 , wherein the coefficient of performance and the cooling capacity of the system is increased by at least 7.5% as compared to a system which uses HFC-134a as the working fluid. 
     
     
         16 . A vapor compression heat transfer system for exchanging heat, comprising:
 (a) an evaporator having an inlet and an outlet;   (b) a compressor having an inlet and an outlet, wherein the inlet is connected to the outlet of the evaporator;   (c) a dual-row condenser connected to the outlet of the compressor, the dual-row condenser having:
 (i) an inlet, 
 (ii) a first row connected to the inlet, the first row comprising a first inlet manifold and a plurality of channels for allowing a working fluid at a first temperature to flow into the manifold and then through the channels in at least one direction and collect in a second outlet manifold, 
 (iii) a second row connected to the first row, the second row comprising a plurality of channels for conducting a working fluid at a second temperature less than the refrigerant in the first row, 
 (iv) conduit connecting the first row to the second row; and 
   (d) an intermediate heat exchanger, having:
 (i) a first tube having an inlet connected to an exit of the condenser and an outlet, and 
 (ii) a second tube having an inlet connected to an outlet and an outlet connected to an inlet of the dual-row condenser; and 
   wherein the inlet of the evaporator is connected to the outlet of the first tube of the intermediate heat exchanger.   
     
     
         17 . A vapor compression heat transfer system for exchanging heat, comprising:
 (a) a dual-row evaporator for evaporating a working fluid, the evaporator having an inlet and an outlet;   (b) a compressor having an inlet and an outlet, wherein the inlet is connected to the outlet of the evaporator;   (c) a condenser having an inlet and an outlet, wherein the inlet is connected to the outlet of the compressor; and   (d) an intermediate heat exchanger having:
 (i) a first tube having an inlet connected to an exit line of a condenser and an outlet connected to an inlet line of the evaporator; 
 (ii) a second tube having an inlet connected to an outlet line of the evaporator having an outlet.