Methods and Systems of Regenerative Heat Exchange

Abstract

The present disclosure teaches apparatuses, systems, and methods for improving energy efficiency using high heat capacity materials. Some embodiments include a phase change material (PCMs). Particularly, the systems may include a re-gasification system, a liquefaction system, or an integrated system utilizing a heat exchanger with a regenerator matrix, a shell and tube arrangement, or cross-flow channels (e.g. a plate-fin arrangement) to store cold energy from a liquefied gas in a re-gasification system at a first location for use in a liquefaction process at a second location. The regenerator matrix may include a plurality of PCMs stacked sequentially or may include a continuous phase material comprised of multiple PCMs. Various encapsulation approaches may be utilized. Reliquefaction may be accomplished with such a system. Natural gas in remote locations may be made commercially viable by converting it to liquefied natural gas (LNG), transporting, and delivering it utilizing the disclosed systems and methods.

1 . A heat transfer system, comprising:
 a regasification system at a first location configured to convert a first volume of liquefied gas (LG) contained at or below a liquefaction temperature into a first volume of gas at above the liquefaction temperature, the regasification system comprising a heat exchange apparatus, comprising:   a regenerator matrix including a volume of high heat capacity materials configured to recover and store cold energy from the LG from the regasification system for subsequent use at a second location to provide at least a portion of a cold energy requirement for liquefaction of a second volume of gas into a second volume of LG.   
     
     
         2 . A heat transfer system, comprising:
 a liquefaction system at a first location configured to convert a first volume of gas at above a liquefaction temperature into a first volume of liquefied gas (LG) contained at or below the liquefaction temperature, the liquefaction system comprising a heat exchange apparatus, comprising:   a regenerator matrix including a volume of high heat capacity materials configured to provide cold energy to the first volume of gas in the liquefaction system, wherein the cold energy is obtained from a regasification system at a second location configured to regasify a second volume of LG contained at liquefaction temperatures.   
     
     
         3 . A heat transfer system, comprising:
 a heat exchange apparatus, comprising:   a regenerator matrix including a volume of high heat capacity materials, wherein the regenerator matrix is configured to:
 a) recover and store cold energy from a volume of liquefied gas at or below a liquefaction temperature from a regasification system at a first location; and 
 b) provide cold energy to a volume of gas at above the liquefaction temperature in a liquefaction system at a second location. 
   
     
     
         4 . The system of any one of  claims 1 - 3 , wherein the heat exchange apparatus is mounted to a liquefied natural gas (LNG) carrier and the liquefied gas (LG) is LNG. 
     
     
         5 . The system of any one of  claims 1 - 3 , wherein the volume of high heat capacity materials includes a phase-change material (PCM). 
     
     
         6 . The system of  claim 5 , wherein the regenerator matrix comprises a series of phase-change materials (PCMs) stacked sequentially based on a phase transition temperature of the PCMs. 
     
     
         7 . The system of  claim 5 , wherein the regenerator matrix comprises a thermo-adjustable mixture of at least two phase-change materials (PCMs) which allow a phase transition temperature to be tuned based on the composition of the mixture, wherein each PCM has a different phase transition temperature. 
     
     
         8 . The system of any one of  claims 1 - 3 , wherein the high heat capacity material is a single composite material configured to span a range of temperatures including the liquefaction temperature. 
     
     
         9 . The system of any one of  claims 1 - 3 , wherein the regenerator matrix is configured to utilize the stored cold energy to re-liquefy a volume of boil-off gas between the first location and the second location. 
     
     
         10 . The system of  claim 5 , wherein the regenerator matrix is in a form selected from the group consisting of: micro-encapsulated spheroids, micro-encapsulated sheets, macro-encapsulated spheroids, macro-encapsulated sheets, a micro-encapsulated honey-comb network, a macro-encapsulated honey-comb network, and a finned heat exchange element. 
     
     
         11 . A method of delivering liquefied natural gas (LNG), comprising:
 flowing LNG to a heat exchange apparatus from an LNG storage tank on an LNG carrier at an LNG gasification location;   recovering cold energy from the LNG using the heat exchange apparatus having a regenerator matrix including a volume of high heat capacity materials to form at least partially vaporized natural gas;   storing the cold energy in the high heat capacity materials for use at an LNG liquefaction location; and   delivering the at least partially vaporized natural gas to a consuming market.   
     
     
         12 . A method of producing natural gas, comprising:
 feeding a natural gas stream to a heat exchange apparatus on a liquefied natural gas (LNG) carrier from a producing location;   passing the natural gas stream through the heat exchange apparatus having a regenerator matrix including a volume of high heat capacity materials, comprising:
 a) imparting cold energy from the high heat capacity materials to the natural gas to form at least partially liquefied natural gas; and 
 b) storing heat energy in the high heat capacity materials for use at an LNG gasification location; and 
   storing the at least partially liquefied natural gas on the LNG carrier.   
     
     
         13 . The method of  claim 11 , further comprising pressurizing the liquefied natural gas (LNG) prior to passing the LNG to the heat exchange apparatus. 
     
     
         14 . The method of  claim 11 , further comprising adding supplemental heat to the at least partially vaporized natural gas to form substantially vaporized natural gas at about an ambient temperature or about a delivery temperature. 
     
     
         15 . The method of any one of  claims 11 - 12 , wherein the volume of high heat capacity materials includes a phase-change material (PCM). 
     
     
         16 . The method of any one of  claims 11 - 12 , wherein the regenerator matrix is in a form selected from the group consisting of: micro-encapsulated spheroids, micro-encapsulated sheets, macro-encapsulated spheroids, macro-encapsulated sheets, a micro-encapsulated honey-comb network, a macro-encapsulated honey-comb network, and a finned heat exchange element. 
     
     
         17 . The method of  claim 15 , wherein the regenerator matrix comprises a series of phase-change materials (PCMs) stacked sequentially based on a phase transition temperature of the PCMs. 
     
     
         18 . The method of  claim 15 , wherein the regenerator matrix comprises a thermo-adjustable mixture of at least two phase-change materials (PCMs) which allow a phase transition temperature to be tuned based on the composition of the mixture, wherein each PCM has a different phase transition temperature. 
     
     
         19 . The method of any one of  claims 11 - 12 , wherein the regenerator matrix is configured to utilize the stored cold energy to re-liquefy a volume of boil-off gas between the liquefaction location and the gasification location. 
     
     
         20 . The method of  claim 12 , further comprising pre-cooling the natural gas feed stream prior to passing the natural gas stream to the heat exchange apparatus. 
     
     
         21 . The method of  claim 12 , further comprising adding supplemental cooling to the at least partially liquefied natural gas to form substantially liquefied natural gas. 
     
     
         22 . A heat transfer system, comprising:
 a regasification system at a first location configured to convert a first volume of liquefied gas (LG) contained at or below a liquefaction temperature into a first volume of gas at above the liquefaction temperature, the regasification system comprising a heat exchange apparatus, comprising:   a shell and tube heat exchanger comprising:
 a) a sealed tube bundle containing a volume of high heat capacity material; and 
 b) the shell side is configured to receive the first volume of liquefied gas (LG) to provide the cold energy to the volume of high heat capacity material in the sealed tube bundle, wherein the volume of high heat capacity material is configured to recover and store cold energy from the LG from the regasification system for subsequent use at a second location to provide at least a portion of a cold energy requirement for liquefaction of a second volume of gas into a second volume of LG. 
   
     
     
         23 . A heat transfer system, comprising:
 a liquefaction system at a first location configured to convert a first volume of gas at above a liquefaction temperature into a first volume of liquefied gas (LG) contained at or below the liquefaction temperature, the liquefaction system comprising a heat exchange apparatus, comprising:   a shell and tube heat exchanger, comprising:
 a) a sealed tubes bundle containing a volume of high heat capacity material configured to store cold energy; and 
 b) the shell side is configured to receive the first volume of gas to receive at least a portion of the stored cold energy, wherein the volume of high heat capacity material is further configured to provide cold energy to the first volume of gas in the liquefaction system, wherein the cold energy is obtained from a regasification system at a second location configured to regasify a second volume of LG contained at liquefaction temperatures. 
   
     
     
         24 . The system of any one of  claims 22 - 23 , wherein each sealed tube in the sealed tube bundle containing the volume of high heat capacity material also is also filled with a non-condensible gas. 
     
     
         25 . The system of  claim 24 , wherein the sealed tubes in the sealed tube bundle containing the volume of high heat capacity material are provided with a non-condensible gas through a connected buffer volume. 
     
     
         26 . The system of any one of  claims 24 - 25 , wherein the volume of high heat capacity materials includes a phase-change material (PCM) configured to utilize at least the latent heat of vaporization. 
     
     
         27 . A method of delivering liquefied natural gas (LNG), comprising:
 flowing LNG to a heat exchange apparatus from an LNG storage tank on an LNG carrier at an LNG gasification location;   recovering cold energy from the LNG utilizing the heat exchange apparatus having a shell and tube heat exchanger including sealed tubes containing a volume of high heat capacity material to form at least partially vaporized natural gas;   storing the cold energy in the high heat capacity materials for use at an LNG liquefaction location; and   delivering the at least partially vaporized natural gas to a consuming market.   
     
     
         28 . The system of  claim 27 , wherein each sealed tube containing the volume of high heat capacity material also is also filled with a non-condensible gas 
     
     
         29 . The system of  claim 27 , wherein the sealed tube containing the volume of high heat capacity material are provided with a non-condensible gas through a connected buffer volume. 
     
     
         30 . The system of any one of  claims 28 - 29 , wherein the volume of high heat capacity materials includes a phase-change material (PCM) configured to utilize at least the latent heat of vaporization. 
     
     
         31 . A heat transfer system, comprising:
 a regasification system at a first location configured to convert a first volume of liquefied gas (LG) contained at or below a liquefaction temperature into a first volume of gas at above the liquefaction temperature, the regasification system comprising a heat exchange apparatus, comprising:   a cross-flow heat exchanger comprising:   a) at least one plugged flow channel containing a volume of high heat capacity material; and   b) at least one open flow channel configured to receive the first volume of liquefied gas (LG) to provide cold energy to the volume of high heat capacity material in the at least one plugged flow channel, wherein the volume of high heat capacity material is configured to recover and store cold energy from the LG from the regasification system for subsequent use at a second location to provide at least a portion of a cold energy requirement for liquefaction of a second volume of gas into a second volume of LG.   
     
     
         32 . The system of  claim 31 , wherein the heat exchange apparatus is selected from the group consisting of: a plate-fin heat exchanger, a plate-frame heat exchanger, a printed-circuit heat exchanger, spiral-wound heat exchanger, and any combination thereof, wherein the heat exchanger alternates from the at least one plugged flow channel to the at least one open flow channel. 
     
     
         33 . The system of  claim 32 , wherein the at least one plugged flow channel further includes a non-condensible gas and the volume of high heat capacity materials includes a phase-change material (PCM) configured to utilize at least the latent heat of vaporization.