Dual-loop cooling system

Abstract

Disclosed are methods and apparatuses for cooling a work piece surface using a dual-loop cooling system. The system includes a vapor-compression loop and a liquid-evaporation loop. The loops are configured to prepare a coolant at or approximately at saturation for delivery into a chamber for cooling the surface. A preferred liquid-evaporation loop includes a chamber, a phase separator, a liquid pressurizer, and a vapor mixer that heats the coolant to or near its saturation temperature. A preferred vapor-compression loop includes the phase separator, a compressor, a condenser, an expansion valve, and a return line. The vapor mixer preferably heats the coolant by mixing liquid coolant with vapor coolant derived from the vapor-compression loop. A two-phase flow detector may be disposed downstream of the vapor mixer and be in communication with a vapor valve disposed upstream of the vapor mixer to ensure that an appropriate amount of vapor is fed into the vapor mixer to induce evaporation. Methods include cooling a surface by cycling a coolant through the liquid-evaporation loop and preparing the coolant at saturation with vapor derived from the vapor-compression loop.

1 . An apparatus for cooling a surface comprising:
 at least one chamber with the surface exposed therein, the chamber comprising an inlet and an outlet and being configured for flowing fluid therethrough by entering through the inlet in a stream projected against the surface and exiting through the outlet;   a liquid source in fluid communication with the inlet of the chamber; and   a heat-transfer apparatus configured to transfer heat to liquid derived from the liquid source upstream of the inlet.   
     
     
         2 . The apparatus of  claim 1  further comprising a heat-transfer regulator configured to adjust amount of heat transferred via the heat-transfer apparatus to the liquid. 
     
     
         3 . The apparatus of  claim 2  wherein the heat-transfer regulator comprises a two-phase flow detector disposed between the heat-transfer apparatus and the inlet, the two-phase flow detector configured to communicate with a device that adjusts an amount of heat transferred via the heat-transfer apparatus to the liquid in response to an amount of vapor phase detected in the liquid. 
     
     
         4 . The apparatus of  claim 1  wherein the heat-transfer apparatus comprises a vapor mixer in fluid communication with the liquid source and a vapor source. 
     
     
         5 . The apparatus of  claim 4  further comprising a vapor valve disposed between the vapor mixer and the vapor source, the vapor valve configured to adjust flow of vapor to the vapor mixer. 
     
     
         6 . The apparatus of  claim 5  further comprising a two-phase flow detector in communication with the vapor valve and disposed between the vapor mixer and the inlet, the two-phase flow detector configured to communicate with the vapor valve to adjust flow of vapor to the vapor mixer in response to an amount of vapor phase detected in the liquid. 
     
     
         7 . The apparatus of  claim 1  wherein the liquid source comprises:
 a phase separator in fluid communication with the outlet of the chamber; and 
 a liquid pressurizer in fluid communication with the phase separator in a configuration to selectively receive liquid therefrom, the liquid pressurizer further being in fluid communication with the heat-transfer apparatus. 
 
     
     
         8 . The apparatus of  claim 1  wherein the heat-transfer apparatus comprises a vapor mixer in fluid communication with the liquid source and a vapor source, wherein the vapor source comprises:
 a phase separator; and 
 a compressor in fluid communication with the phase separator in a configuration to selectively receive vapor therefrom, the compressor further being in regulated fluid communication with the vapor mixer. 
 
     
     
         9 . The apparatus of  claim 8  further comprising:
 a condenser in fluid communication with the compressor in a configuration to receive fluid therefrom and further in fluid communication with the phase separator via a return line in a configuration to deliver fluid to the phase separator; and 
 an expansion valve disposed between the condenser and the return line. 
 
     
     
         10 . The apparatus of  claim 9  wherein the condenser is further in fluid communication with the inlet of the chamber to deliver fluid thereto, the chamber is in fluid communication with the phase separator to deliver fluid thereto, and the apparatus further comprises:
 a circuit valve disposed between the expansion valve and the inlet, the circuit valve configured to adjust flow of fluid from the expansion valve to the inlet. 
 
     
     
         11 . The apparatus of  claim 10  further comprising:
 a first fluid loop comprising:
 the chamber; 
 a phase separator as the liquid source, wherein the phase separator is in fluid communication with the outlet of the chamber; 
 a liquid pressurizer in fluid communication with the phase separator in a configuration to selectively receive liquid therefrom, the liquid pressurizer further being in fluid communication with the heat-transfer apparatus; and 
 the vapor mixer; and 
 
 a second fluid loop comprising:
 the phase separator; 
 the compressor; 
 the condenser; 
 the expansion valve; and 
 the return line, 
 
 wherein the apparatus is configured to cycle fluid through the first fluid loop and at least intermittently cycle fluid simultaneously through the second fluid loop. 
 
     
     
         12 . The apparatus of  claim 1  wherein the heat-transfer apparatus comprises a heat exchanger. 
     
     
         13 . The apparatus of  claim 1  wherein the heat-transfer apparatus comprises a jet pump. 
     
     
         14 . A method of cooling a surface within a chamber comprising:
 preparing a coolant approximately at saturation, wherein the preparing comprises heating pre-heated coolant to approximately a saturation temperature to generate heated coolant;   introducing the heated coolant through an inlet of the chamber which includes projecting a stream of the heated coolant against the surface, wherein the heated coolant at least partially evaporates as it enters the chamber prior to contacting the surface; and   draining partially evaporated coolant through an outlet of the chamber.   
     
     
         15 . The method of  claim 14  further comprising detecting amount of vapor phase in the heated coolant and regulating the heating in response to the amount of detected vapor phase. 
     
     
         16 . The method of  claim 14  wherein the heating comprises:
 collecting the partially evaporated coolant draining from the outlet of the chamber to obtain collected coolant; 
 separating the collected coolant into liquid coolant and vapor coolant; 
 selectively pressurizing the liquid coolant to obtain pressurized liquid coolant; and 
 heating the pressurized liquid coolant. 
 
     
     
         17 . The method of  claim 14  wherein the heating comprises mixing the pre-heated coolant with vapor. 
     
     
         18 . The method of  claim 17  wherein the heating comprises:
 collecting vapor-containing coolant to obtain collected coolant; 
 separating the collected coolant into liquid coolant and vapor coolant; 
 selectively compressing the vapor coolant to obtain compressed vapor coolant; and 
 mixing at least a first portion of the compressed vapor coolant with the pre-heated coolant. 
 
     
     
         19 . The method of  claim 18  further comprising:
 condensing at least a second portion of the compressed vapor coolant to generate condensed coolant; 
 expanding the condensed coolant to approximately a saturation pressure of the condensed coolant to generate expanded coolant; and 
 performing a process selected from the group consisting of:
 recycling at least a first portion of the expanded coolant, wherein the first portion of the expanded coolant comprises at least a portion of the vapor-containing coolant in the collecting step; and 
 mixing at least a second portion of the expanded coolant with the heated coolant prior to the introducing the heated coolant through the inlet of the chamber, wherein the collecting the vapor-containing coolant includes collecting the partially evaporated coolant draining from the outlet of the chamber. 
 
 
     
     
         20 . A method of cooling a surface within a chamber comprising cycling fluid through a first loop and at least intermittently cycling fluid simultaneously through a second loop, wherein:
 the cycling through a first loop comprises:
 introducing a substantially saturated coolant through an inlet of the chamber which includes projecting a stream of the substantially saturated coolant against the surface, wherein the substantially saturated coolant at least partially evaporates as it enters the chamber prior to contacting the surface; 
 draining partially evaporated coolant through an outlet of the chamber; 
 collecting the partially evaporated coolant to obtain collected coolant; 
 separating the collected coolant into liquid coolant and vapor coolant; 
 selectively pressurizing the liquid coolant to obtain pressurized liquid coolant prior to the introducing; and 
   the cycling through the second loop comprises:
 the collecting, wherein the collecting further comprises collecting vapor-containing coolant; 
 the separating; 
 selectively compressing the vapor coolant to obtain compressed vapor coolant; 
 mixing at least a first portion of the compressed vapor coolant with the pressurized liquid coolant to generate the coolant substantially at saturation; 
 condensing at least a second portion of the compressed vapor coolant to generate condensed coolant; 
 expanding the condensed coolant to approximately a saturation pressure of the condensed coolant to generate expanded coolant; and 
 performing a process selected from the group consisting of:
 recycling at least a first portion of the expanded coolant, wherein the first portion of the expanded coolant comprises at least a portion of the vapor-containing coolant; and 
 mixing at least a second portion of the expanded coolant with the coolant substantially at saturation prior to the introducing, wherein the collecting the vapor-containing coolant includes collecting the partially evaporated coolant draining from the outlet of the chamber.