Method and Apparatus for Cooling in Liquefaction Process

Abstract

Methods and apparatus are disclosed for efficient cooling within air liquefaction processes with integrated use of cold recycle from a thermal energy store.

1 . A cryogenic liquefaction device comprising:
 a heat exchanger;   a first phase separator;   a first expansion device;   a first expansion turbine;   a second expansion turbine;   a cold recovery circuit including a heat transfer fluid; and   an arrangement of conduits, wherein:   the operating inlet pressures of the first and second expansion turbines are different from one another; and   the arrangement of conduits is arranged such that:
 a first portion of a pressurised stream of gas is directed through the heat exchanger, the first expansion device and the first phase separator; 
 a second portion of the pressurised stream of gas is directed through the first expansion turbine, then through the heat exchanger in a counter-flow direction to the first portion of the pressurised stream of gas, and then through the second expansion turbine, and 
 the heat transfer fluid is directed through the heat exchanger. 
   
     
     
         2 . The cryogenic liquefaction device of  claim 1  wherein the cold recovery circuit comprises:
 a thermal energy storage device; 
 a means for circulating the heat transfer fluid; and 
 an arrangement of conduits arranged to direct the heat transfer fluid through the thermal energy storage device and the heat exchanger. 
 
     
     
         3 . The cryogenic liquefaction device of  claim 1 , wherein the pressurised stream of gas consists of gaseous air or gaseous nitrogen. 
     
     
         4 . The cryogenic liquefaction device of  claim 3 , wherein the pressurised stream of gas is input into the cryogenic liquefaction device at a pressure greater than or equal to the critical pressure. 
     
     
         5 . The cryogenic liquefaction device of  claim 1 , wherein the first portion of the pressurised stream of gas and the second portion of the pressurised stream of gas are at different pressures. 
     
     
         6 . The cryogenic liquefaction device of  claim 1 , wherein the first portion of the pressurised stream of gas and the second portion of the pressurised stream of gas are at the same pressure. 
     
     
         7 . The cryogenic liquefaction device of  claim 1 , and further comprising a third expansion turbine, wherein:
 the operating inlet pressure of the third expansion turbine is different to at least one of the first and second expansion turbines.   
     
     
         8 . The cryogenic liquefaction device of  claim 7 , wherein the arrangement of conduits is such that the third expansion turbine is in parallel with at least one of the first and second turbines such that at least a portion of the second portion of the pressurised stream of process gas is directed through the third turbine. 
     
     
         9 . The cryogenic liquefaction device of  claim 7 , wherein the arrangement of conduits is such that the third expansion turbine is in series with at least one of the first and second turbines such that at least a portion of the second portion of the pressurised stream of process gas is directed through the third turbine. 
     
     
         10 . The cryogenic liquefaction device of  claim 1 , and further comprising a refrigerant circuit which is connected to an output of the second expansion turbine via the arrangement of conduits. 
     
     
         11 . The cryogenic liquefaction device of  claim 1 , and further comprising a second arrangement of conduits that directs a second heat transfer fluid through a closed cycle refrigeration circuit and through a localised area of the heat exchanger. 
     
     
         12 . The cryogenic liquefaction device of  claim 11 , wherein the second heat transfer fluid comprises a gas or a liquid. 
     
     
         13 . The cryogenic liquefaction device of  claim 7 , and further comprising a fourth expansion turbine, wherein:
 the arrangement of conduits is arranged such that:
 a third portion of the pressurised stream of gas is directed through the fourth expansion turbine, and then through the heat exchanger in a counter-flow direction to the first portion of the pressurised stream of gas. 
   
     
     
         14 . The cryogenic liquefaction device of  claim 13 , and further comprising a fifth expansion turbine, wherein:
 the arrangement of conduits is arranged such that:
 the third portion of the pressurised stream of gas is directed through the fifth expansion turbine after passing through the fourth expansion turbine and the heat exchanger. 
   
     
     
         15 . The cryogenic liquefaction device of  claim 1 , wherein the first expansion device comprises at least one of a Joule-Thomson valve, another pressure reducing valve, an expansion turbine and another work extracting device. 
     
     
         16 . The cryogenic liquefaction device of  claim 1 , and further comprising a second phase separator and a second expansion device, wherein the arrangement of conduits is arranged such that at least a portion of the second portion of the pressurised stream of gas is directed through the second expansion device and the second phase separator after having passed through the first expansion turbine. 
     
     
         17 . The cryogenic liquefaction device of  claim 16 , wherein the second expansion device comprises at least one of a Joule-Thomson valve, another pressure reducing valve, an expansion turbine and another work extracting device. 
     
     
         18 . The cryogenic liquefaction device of  claim 1 , and further comprising a first compressor, wherein the arrangement of conduits is arranged such that at least a portion of the second portion of the pressurised stream of gas is directed through the first compressor before passing through the first expansion turbine. 
     
     
         19 . The cryogenic liquefaction device of  claim 18 , and further comprising a second compressor, wherein the arrangement of conduits is arranged such that the first portion of the pressurised stream of gas is directed through the second compressor before passing through the heat exchanger. 
     
     
         20 . The cryogenic liquefaction device of  claim 19 , and further comprising a cooler, wherein the arrangement of conduits is arranged such that the first portion of the pressurised stream of gas is directed through the cooler after passing through the second compressor and before passing through the heat exchanger. 
     
     
         21 . The cryogenic liquefaction device of  claim 1 , wherein the output from the second expansion turbine is directed into the first phase separator. 
     
     
         22 . The cryogenic liquefaction device of  claim 7 , wherein an output from the third expansion turbine is directed into the first phase separator. 
     
     
         23 . The cryogenic liquefaction device of  claim 13 , wherein an output from the fourth expansion turbine is directed into the first phase separator. 
     
     
         24 . The cryogenic liquefaction device of  claim 14 , wherein an output from the fifth expansion turbine is directed into the first phase separator. 
     
     
         25 . The cryogenic liquefaction device of  claim 1 , further comprising a feed stream compressor adapted to output the pressurized stream of gas, wherein the arrangement of conduits is arranged such that:
 a) a feed stream is directed to an input of the feed stream compressor; and   b) an output stream from the first phase separator joins the feed stream after passing through the heat exchanger.   
     
     
         26 . The cryogenic liquefaction device of  claim 25 , wherein the arrangement of conduits is arranged such that the pressurized stream of gas output from the feed stream compressor is directed to a heat storage device before passing through the heat exchanger. 
     
     
         27 . The cryogenic liquefaction device of  claim 26 , wherein the arrangement of conduits is arranged such that a pressurized stream of gas output from the heat storage device is directed to a heat rejection device before passing through the heat exchanger. 
     
     
         28 . A cryogenic liquefaction device comprising:
 a heat exchanger;   a first phase separator;   a first expansion device;   a first expansion turbine;   a first compressor;   a cold recovery circuit including a heat transfer fluid; and   an arrangement of conduits, arranged such that:
 a first portion of a pressurised stream of gas is directed through the heat exchanger, the first expansion device and the first phase separator; 
 a second portion of the pressurised stream of gas is directed through the first expansion turbine, then through the heat exchanger in a counter-flow direction to the first portion of the pressurised stream of gas, and then through the first compressor, and 
 the heat transfer fluid is directed through the heat exchanger. 
   
     
     
         29 . The cryogenic liquefaction device of  claim 28 , wherein the arrangement of conduits is arranged such that an output stream of the first compressor joins the pressurised stream of gas. 
     
     
         30 . The cryogenic liquefaction device of  claim 29 , wherein the arrangement of conduits is arranged such that the output stream of the first compressor is directed into the heat exchanger before it joins the pressurised stream of gas. 
     
     
         31 . The cryogenic liquefaction device of  claim 29 , wherein the arrangement of conduits is arranged such that the output stream of the first compressor joins the pressurised stream of gas before it is directed into the heat exchanger. 
     
     
         32 . The cryogenic liquefaction device of  claim 28 , wherein the first compressor is one of a single stage and a multistage compressor. 
     
     
         33 . A cryogenic energy storage device including the cryogenic liquefaction device  claim 1 . 
     
     
         34 . A method for balancing a liquefaction process with the use of cold recycle from an external thermal energy source comprising:
 directing a first portion of a pressurised stream of gas through a heat exchanger, a first expansion device, and a first phase separator;   directing a second portion of a pressurised stream of gas through a first expansion turbine, then through the heat exchanger in a counter-flow direction to the first portion of the pressurised stream of gas, and then through a second expansion turbine; and   directing a heat transfer fluid through a cold recovery circuit and the heat exchanger; wherein:   operating inlet pressures of the first and second expansion turbines are different from one another.   
     
     
         35 . A method for balancing a liquefaction process with the use of cold recycle from an external thermal energy source comprising:
 directing a first portion of a pressurised stream of gas through a heat exchanger, a first expansion device, and a first phase separator;   directing a second portion of a pressurised stream of gas through a first expansion turbine, then through the heat exchanger in a counter-flow direction to the first portion of the pressurised stream of gas, and then through a first compressor; and   directing a heat transfer fluid through a cold recovery circuit and the heat exchanger.   
     
     
         36 . A method of storing energy including the method for balancing a liquefaction process of  claim 34 . 
     
     
         37 . A method of storing energy including the method for balancing a liquefaction process of  claim 35 .