LNG regassification process and system

Abstract

A system for vaporizing liquefied natural gas (LNG) utilizes the residual cooling capacity of LNG to condense the working fluid of a power producing work producing cycle and chills liquids that are used in a direct-contact heat transfer system to cool air. The cold air is used to supply air to a combustion gas turbine operating in conjunction with a combined cycle power plant. Power is produced from both the work producing cycle and the combined cycle power plant and the chilling of the intake air to the gas turbine increases the output capacity of the combined cycle power plant.

What is claimed is:  
     
         1 . A system for the production of power and the vaporization of liquid hydrocarbons that uses the residual cooling capacity of the liquid hydrocarbons to improve power production efficiency, the system comprising: 
 a first heat exchanger passing the hydrocarbons in a heat exchange relationship with a working fluid in a power producing cycle that utilizes the working fluid to produce power, wherein at least a portion of the hydrocarbons are vaporized and at least a portion of the first fluid is condensed in said first heat exchanger;    an air cooling system wherein the hydrocarbons are used in a heat exchange relationship so that the hydrocarbons are warmed and a stream of chilled air is produced; and    an engine that uses a portion of the vaporized hydrocarbons mixed with the stream of chilled air to produce power.    
     
     
         2 . The system of  claim 1  wherein the working fluid is condensed in said first heat exchanger and the work producing cycle is a Rankine cycle that further comprises: 
 a second heat exchanger wherein the condensed working fluid is vaporized by being passed in a heat exchange relationship with a heat exchange medium at a higher temperature than the condensed working fluid; and  
 an expander that produces useful work by the expansion of the vaporized working fluid.  
 
     
     
         3 . The system of  claim 2  wherein the heat exchange medium is at ambient temperature.  
     
     
         4 . The system of  claim 1  wherein said working fluid has a boiling point between −350° F. and −100° F.  
     
     
         5 . The system of  claim 4  wherein said first fluid is an organic hydrocarbon.  
     
     
         6 . The system of  claim 1  wherein said air cooling system further comprises a second heat exchanger passing the hydrocarbons in a heat exchange relationship with a first cooling fluid, wherein the temperature of the hydrocarbons is increased and the temperature of the first cooling fluid is decreased, wherein the first cooling fluid is further used to lower the temperature of a stream of air.  
     
     
         7 . The system of  claim 6  wherein the air cooling system comprises an air cooling chamber where the stream of air is exposed to the first cooling fluid in a direct contact heat exchange relationship.  
     
     
         8 . The system of  claim 6  further comprising a third heat exchanger passing the hydrocarbons in heat exchange relationship with a second cooling fluid so that the temperature of the hydrocarbons is increased and the temperature of the second cooling fluid is decreased, wherein the second cooling fluid is further used to lower the temperature of a stream of air..  
     
     
         9 . The system of  claim 8  wherein the air cooling system further comprises a first cooling chamber where an air flow is exposed in a direct contact heat exchange relationship with the first cooling fluid, and a second cooling chamber where the air flow is exposed in a direct contact heat exchange relationship with the second cooling fluid.  
     
     
         10 . The system of  claim 9  wherein at least one of said first or second cooling fluids has a freezing temperature lower than the freezing temperature of water.  
     
     
         11 . The system of  claim 6  wherein said first cooling fluid is circulated counter-currently to the air stream.  
     
     
         12 . The system of  claim 10  wherein the air is cooled to a temperature of at least −20° Fahrenheit.  
     
     
         13 . The system of  claim 1  wherein said engine is a gas turbine.  
     
     
         14 . The system of  claim 13  further comprising a heat recovery steam generator that uses the exhaust gases from the gas turbine to create work.  
     
     
         15 . A method for producing power from the vaporization and use of a liquid hydrocarbon product, the method comprising: 
 vaporizing at least a portion of the liquid hydrocarbon produce by circulating the product in a heat exchange relationship with a working fluid so as to condense the working fluid, wherein the working fluid is used in a work producing cycle; and    circulating the hydrocarbon product in a heat exchange relationship in an air cooling system so that the temperature of the product increases and a stream of chilled air is produced.    
     
     
         16 . The method of  claim 15  further comprising: 
 mixing at least a portion of the hydrocarbon product with the chilled air stream; and  
 burning the hydrocarbon and air mixture in a power plant.  
 
     
     
         17 . The method of  claim 15  further comprising: 
 vaporizing the working fluid by exposure in a heat exchange relationship to a heat exchange medium;  
 expanding the working fluid through an expander that is coupled to a generator.  
 
     
     
         18 . The method of  claim 17  wherein the heat exchange is at ambient conditions.  
     
     
         19 . The method of  claim 15  wherein the chilled air stream is produced by: 
 exposing the stream of air in a direct contact heat exchange relationship to a first cooling liquid that is cooled in a heat exchange relationship with the hydrocarbon product; and  
 exposing the stream of air in a direct contact heat exchange relationship to a second cooling liquid that is cooled in a heat exchange relationship with the hydrocarbon product.  
 
     
     
         20 . The method of  claim 19  wherein the first cooling liquid is chilled to a temperature above the freezing point of water and the second cooling liquid is chilled to a temperature below the freezing point of water.  
     
     
         21 . The method of  claim 15  further comprising: 
 mixing the chilled air stream and at least a portion of the vaporized hydrocarbon product in the combustion chamber of a gas turbine; and  
 burning the air and hydrocarbon mixture to produce power through the gas turbine.  
 
     
     
         22 . The method of  claim 21  further comprising exhausting hot exhaust gases from the gas turbine to a heat recovery steam generator that uses the heat of the exhaust gases to generate power.  
     
     
         23 . A system for the vaporization of hydrocarbons comprising: 
 a first exchanger passing the hydrocarbons in a heat exchange relationship with a first fluid in a work producing cycle;    a second heat exchanger passing the hydrocarbons in heat exchange relationship with a second fluid in an air cooling system to produce a chilled air stream; and    an engine that burns a mixture of the hydrocarbons and chilled air stream to produce power.    
     
     
         24 . The system of  claim 23  wherein the work producing cycle produces power.  
     
     
         25 . The system of  claim 23  further comprising a third exchanger passing the liquid hydrocarbons in heat exchange relationship with a third working fluid in said air cooling system.  
     
     
         26 . The system of  claim 23  wherein said first fluid is condensed in said first exchanger and the work producing cycle is a Rankine cycle that further comprises: 
 a third heat exchanger to vaporize the first fluid; and  
 an expander to convert the energy of the vaporized first fluid into useful energy by using a generator.  
 
     
     
         27 . The system of  claim 26  wherein the third heat exchanger passes the first fluid in heat exchange relationship with a compound at ambient temperature.  
     
     
         28 . The system of  claim 23  wherein the air cooling system comprises an air cooling chamber where a flow of air is exposed to the second fluid in a direct contact heat exchange relationship.  
     
     
         29 . The system of  claim 23  further comprising a fourth heat exchanger passing the hydrocarbons in heat exchange relationship with a third fluid, and wherein the air cooling system further comprises a first cooling chamber where an air flow is exposed in a direct contact heat exchange relationship with the third fluid at a temperature above the freezing point of water, and a second cooling chamber where an air flow is exposed in a direct contact heat exchange relationship with the second fluid below the freezing point of water.