Systems and Methods for Regenerative Ejector-Based Cooling Cycles

Abstract

Systems and methods for regenerative ejector-based cooling cycles that utilize an ejector as the motivating force in a cooling loop to regeneratively sub-cool a refrigerant in a single-stage cooling cycle.

1 . A system for use with a refrigerant in a regenerative cooling cycle, which comprises:
 an ejector for mixing a condensed liquid form of the refrigerant and a first vaporized form of the refrigerant to form a two-phase form of the refrigerant;   a flash tank in fluid communication with the ejector for separating the two-phase form of the refrigerant from the ejector into a second vaporized form of the refrigerant and a liquid form of the refrigerant;   a sub-cooler connected to the ejector by a vaporized refrigerant line for cooling a portion of the liquid form of the refrigerant from a liquid refrigerant line fluidly connected to the flash tank and vaporizing another two-phase form of the refrigerant;   an evaporator in fluid communication with the sub-cooler and the flash tank for producing a third vaporized form of the refrigerant;   a compressor connected to the flash tank for compressing the second vaporized form of the refrigerant; and   a heat exchanger connected to the compressor and the ejector for cooling a compressed vaporized form of the refrigerant and producing the condensed liquid form of the refrigerant.   
     
     
         2 . The system of  claim 1 , further comprising a pump positioned between the flash economizer and the sub-cooler for distributing the liquid form of the refrigerant. 
     
     
         3 . The system of  claim 1 , further comprising a pump positioned upstream from the ejector for increasing at least one of a discharge pressure at the ejector and an intermediate pressure at the flash economizer. 
     
     
         4 . The system of  claim 1 , wherein a temperature and a pressure for the second vaporized form of the refrigerant are substantially 72° F. and substantially 89 psia, respectively. 
     
     
         5 . The system of  claim 1 , wherein a temperature and a pressure for the liquid form of the refrigerant are substantially 95° F. and substantially 129 psia, respectively. 
     
     
         6 . The system of  claim 1 , wherein a temperature and a pressure for the sub-cooled liquid form of the refrigerant are substantially 68° F. and substantially 88 psia, respectively. 
     
     
         7 . The system of  claim 1 , wherein a temperature and a pressure for the two-phase form of the refrigerant are substantially 72° F. and substantially 89 psia, respectively. 
     
     
         8 . The system of  claim 1 , wherein a temperature of the subcooled liquid form of the refrigerant is about 4° F. less than a temperature of the two-phase form of the refrigerant. 
     
     
         9 . A regenerative cooling method, which comprises:
 mixing a condensed liquid form of a refrigerant and a first vaporized form of the refrigerant to form a two-phase form of the refrigerant;   separating the two-phase form of the refrigerant into a second vaporized form of the refrigerant and a liquid form of the refrigerant;   cooling a first portion of the liquid form of the refrigerant by transferring heat from the first portion of the liquid form of the refrigerant to another two-phase form of the refrigerant to form the first vaporized form of the refrigerant and a separate sub-cooled liquid form of the refrigerant;   compressing the second vaporized form of the refrigerant to form a compressed vaporized form of the refrigerant; and   cooling the compressed vaporized form of the refrigerant to form the condensed liquid form of the refrigerant.   
     
     
         10 . The method of  claim 9 , further comprising heating the separate sub-cooled liquid form of the refrigerant by transferring heat from an external source to the sub-cooled liquid form of the refrigerant and producing a third vaporized form of the refrigerant. 
     
     
         11 . The method of  claim 9 , further comprising compressing the second vaporized form of the refrigerant. 
     
     
         12 . The method of  claim 9 , further comprising increasing at least one of a discharge pressure at an ejector and an intermediate pressure at a flash economizer with a pump. 
     
     
         13 . The method of  claim 9 , wherein a temperature and a pressure for the second vaporized form of the refrigerant are substantially 72° F. and substantially 89 psia, respectively. 
     
     
         14 . The method of  claim 9 , wherein a temperature and a pressure for the liquid form of the refrigerant are substantially 95° F. and substantially 129 psia, respectively. 
     
     
         15 . The method of  claim 9 , wherein a temperature and a pressure for the separate sub-cooled liquid form of the refrigerant are substantially 68° F. and substantially 88 psia, respectively. 
     
     
         16 . The method of  claim 9 , wherein a temperature and a pressure for the two-phase form of the refrigerant are substantially 72° F. and substantially 89 psia, respectively. 
     
     
         17 . The method of  claim 9 , wherein a temperature and a pressure for the first vaporized form of the refrigerant are substantially 60° F. and substantially 72 psia, respectively. 
     
     
         18 . The method of  claim 9 , wherein a temperature of the subcooled liquid form of the refrigerant is about 4° F. less than a temperature of the two-phase form of the refrigerant. 
     
     
         19 . The method of  claim 9 , wherein the refrigerant is a refrigerant with a cooling duty of 5.4 MW for cooling a circulating cooling water system from substantially 86° F. to substantially 72° F.