Integrated absorption-cycle refrigeration and power generation system

Abstract

An integrated power and refrigeration system is disclosed. The integrated system includes a solution comprising an absorber fluid and a working fluid that can be selectively dissolved into the absorber fluid. The integrated system also includes a first subsystem configured to extract heat from an external cooling load by pumping the solution through a vapor absorption cycle and a second subsystem configured to provide power by accepting a first portion of the solution from the first subsystem, extracting at least a portion of the working fluid from the accepted solution, heating the extracted working fluid, using the heated extracted working fluid to drive a turbine that is coupled to a power generator, and then returning the extracted working fluid and the remaining accepted solution to the first subsystem.

What is claimed is: 
     
         1 . An integrated power and refrigeration system comprising:
 a solution comprising an absorber fluid and a working fluid that can be selectively dissolved into the absorber fluid;   a first subsystem configured to extract heat from an external cooling load by pumping the solution through a vapor absorption cycle; and   a second subsystem configured to provide power by accepting a first portion of the solution from the first subsystem, extracting at least a portion of the working fluid from the accepted solution, heating the extracted working fluid, expanding the heated extracted working fluid to extract work thereby driving a turbine that is coupled to a power generator, and then returning the expanded working fluid and the remaining accepted solution to the first subsystem.   
     
     
         2 . The system of  claim 1 , wherein:
 the solution is characterized as a strong solution when the amount of the working fluid that is dissolved in the absorber fluid is greater than a determined percentage and characterized as a weak solution when the amount of the working fluid that is dissolved in the absorber fluid is less than or equal to the determined percentage; and   the first subsystem comprises:
 a first pump configured to accept a strong solution, increase the pressure of the accepted strong solution, and provide a pressurized strong solution; and 
 a first generator thermally coupled to an engine, the first generator configured to accept a second portion of the pressurized strong solution, extract a portion of the working fluid from the accepted pressurized strong solution using heat extracted from the engine, and provide both a pressurized working fluid and a weak solution. 
   
     
     
         3 . The system of  claim 2 , wherein the second subsystem comprises:
 a second generator thermally coupled to the engine, the second generator configured to accept the first portion of the pressurized strong solution received from the first subsystem, extract a portion of the working fluid from the pressurized strong solution using heat extracted from the propulsive engine, and provide both a pressurized working fluid and a weak solution;   a superheater thermally coupled to the engine, the superheater configured to accept the pressurized working fluid, heat the pressurized working fluid using heat extracted from the engine, and provide a hot pressurized working fluid;   a power generator configured to provide power; and   a turbine coupled to the power generator, the turbine configured to accept the hot pressurized working fluid from the superheater, expand and extract work from the hot pressurized working fluid thereby driving the power generator, and provide a working fluid.   
     
     
         4 . The system of  claim 3 , wherein the turbine is further coupled to the first pump and a portion of the work extracted from the hot pressurized working fluid drives the first pump. 
     
     
         5 . The system of  claim 4 , wherein:
 the second subsystem further comprises a second pump configured to accept the first portion of pressurized strong solution received from the first subsystem, increase the pressure of the accepted pressurized strong solution, and provide a highly pressurized strong solution;   the second generator is configured to accept the highly pressurized strong solution from the second pump in place of the pressurized strong solution from the first subsystem and to provide a highly pressurized working fluid in place of the pressurized working fluid;   the superheater is configured to accept the highly pressurized working fluid in place of the pressurized working fluid and to provide a hot highly pressurized working fluid in place of the hot pressurized working fluid;   the turbine is further coupled to the second pump; and   the turbine is configured to accept the hot highly pressurized working fluid in place of the hot pressurized working fluid and expand and extract work from the hot highly pressurized working fluid thereby driving the power generator and the first and second pumps.   
     
     
         6 . The system of  claim 4 , wherein:
 the first subsystem further comprises an absorber configured to accept the working fluid from both the evaporator and the turbine and the weak solution from both the first and second generators, dissolve the accepted working fluid in the accepted weak solution, and provide a strong solution to the first pump.   
     
     
         7 . The system of  claim 2 , wherein the engine is a Brayton-cycle engine. 
     
     
         8 . The system of  claim 2 , wherein the engine is a Otto-cycle engine. 
     
     
         9 . The system of  claim 2 , wherein the engine is a Diesel-cycle engine. 
     
     
         10 . An integrated power and refrigeration system comprising:
 a solution comprising an absorber fluid and a working fluid selected such that the working fluid can be at least partially absorbed into the absorber fluid, wherein the solution is characterized as a strong solution when the percentage of working fluid is greater than a determined value and characterized as a weak solution when the percentage of working fluid is less than or equal to the determined value;   a first pump configured to accept a flow of strong solution, increase the pressure of the accepted strong solution, and provide a flow of pressurized strong solution;   a low-pressure generator coupled to a heat source, the low-pressure generator configured to accept a first portion of the pressurized strong solution flow from the first pump, extract at least a portion of the working fluid from the strong solution using heat extracted from the heat source, and provide both a flow of pressurized working fluid and a flow of weak solution;   a condenser coupled to a cooling medium, the condenser configured to accept the pressurized working fluid from the low-pressure generator, decrease the temperature of the accepted pressurized working fluid by rejecting heat to the cooling medium, and provide a flow of cool pressurized working fluid;   a throttle configured to accept the flow of cool pressurized working fluid from the condenser and reduce the pressure of the cool pressurized working fluid so as to vaporize a portion of the cool pressurized working fluid thereby reducing the temperature of the fluid, and provide a flow of cold working fluid;   an evaporator coupled to an external cooling load, the evaporator configured to accept the flow of cold working fluid from the throttle, vaporize at least a further portion of the cold working fluid using heat extracted from the external cooling load, and provide a flow of working fluid;   a second pump configured to accept a second portion of the pressurized strong solution flow from the first pump, increase the pressure of the accepted pressurized strong solution, and provide a flow of highly pressurized strong solution;   a high-pressure generator coupled to the heat source, the high-pressure generator configured to accept the highly pressurized strong solution flow from the second pump, extract at least a portion of the working fluid from the strong solution using heat extracted from the heat source, and provide both a flow of highly pressurized working fluid and a flow of weak solution;   a superheater coupled to the heat source, the superheater configured to accept the highly pressurized working fluid from the high-pressure generator, increase the temperature of the accepted highly pressurized working fluid using heat extracted from the heat source, and provide a flow of hot highly pressurized working fluid;   a power generator configured to provide power;   a power turbine coupled to the power generator and the first and second pumps, the power turbine configured to accept the hot highly pressurized working fluid, expand and extract work from the hot highly pressurized working fluid thereby driving the power generator and the first and second pumps, and provide a flow of working fluid;   a first cooler coupled to the cooling medium, the first cooler configured to accept the flows of working fluid from both the evaporator and the turbine, reject heat from the accepted working fluid to the cooling medium, and provide a flow of working fluid;   a second cooler coupled to the cooling medium, the second cooler configured to accept the flows of weak solution from both the low-pressure generator and the high-pressure generator, reject heat from the accepted weak solution to the cooling medium, and provide a flow of weak solution; and   an absorber configured to accept the flow of weak solution from the second cooler and the flow of working fluid from the first cooler, dissolve the working fluid in the weak solution to create a strong solution, and provide a flow of the strong solution to the first pump.   
     
     
         11 . The system of  claim 10 , wherein the heat source is waste heat from an engine. 
     
     
         12 . The system of  claim 10 , wherein the cooling medium is ambient air. 
     
     
         13 . A method of providing power and refrigeration on a vehicle having an engine, the method comprising the steps of:
 pressurizing a strong solution wherein the percentage of a working fluid dissolved in an absorber fluid is greater than a determined value;   extracting at least a portion of the working fluid from the pressurized strong solution using heat extracted from the engine;   condensing a first portion of the extracted working fluid by rejecting heat to a cooling medium;   providing refrigeration to an external cooling load by evaporating the condensed working fluid using heat extracted from the external cooling load;   heating a second portion of the extracted working fluid using heat extracted from the engine; and   providing power by expanding and extracting work from the heated second portion of the extracted working fluid in a turbine that is coupled to a power generator.   
     
     
         14 . The method of  claim 13 , wherein the step of providing power comprises driving a first pump to perform the step of pressurizing the strong solution. 
     
     
         15 . The method of  claim 13 , further comprising the steps of:
 further pressurizing a portion of the pressurized strong solution to form a highly pressurized strong solution; and   extracting a highly pressurized working fluid from the highly pressurized strong solution using heat extracted from the engine;   
       wherein:
 the step of heating a second portion of the extracted working fluid comprises heating the highly pressurized working fluid; and 
 the step of providing power comprises expanding and extracting work from the heated highly pressurized working fluid. 
 
     
     
         16 . The method of  claim 15 , wherein the step of providing power comprises driving a second pump to perform the step of further pressurizing a portion of the pressurized strong solution. 
     
     
         17 . The method of  claim 13 , further comprising the step of:
 dissolving the evaporated working fluid that was used to provide cooling and the expanded working fluid that was used to provide power in a weak solution wherein the percentage of the working fluid dissolved in the absorber fluid is less than or equal to the determined value that was formed from the strong solution when the working fluid was extracted.   
     
     
         18 . A power system comprising:
 a solution comprising an absorber fluid and a working fluid selected such that the working fluid can be at least partially absorbed into the absorber fluid, wherein the solution is characterized as a strong solution when the percentage of working fluid is greater than a determined value and characterized as a weak solution when the percentage of working fluid is less than or equal to the determined value;   a pump configured to accept a flow of strong solution, increase the pressure of the accepted strong solution, and provide a flow of pressurized strong solution;   a generator coupled to a heat source, the generator configured to accept the pressurized strong solution flow from the pump, extract at least a portion of the working fluid from the strong solution using heat extracted from the heat source, and provide both a flow of pressurized working fluid and a flow of weak solution;   a superheater coupled to the heat source, the superheater configured to accept the pressurized working fluid flow from the generator, increase the temperature of the accepted pressurized working fluid using heat extracted from the heat source, and provide a flow of hot pressurized working fluid;   a power generator configured to provide power;   a power turbine coupled to the power generator and the pump, the power turbine configured to accept the hot pressurized working fluid from the superheater, expand and extract work from the hot pressurized working fluid thereby driving the power generator and the pump, and provide a flow of expanded working fluid; and   an absorber configured to accept the flow of weak solution and the flow of expanded working fluid, dissolve the working fluid into the weak solution to create a strong solution, and provide a flow of the strong solution to the pump.   
     
     
         19 . The power system of  claim 18 , wherein the heat source is waste heat from an engine. 
     
     
         20 . A refrigeration system comprising:
 a solution comprising an absorber fluid and a working fluid selected such that the working fluid can be at least partially absorbed into the absorber fluid, wherein the solution is characterized as a strong solution when the percentage of working fluid is greater than a determined value and characterized as a weak solution when the percentage of working fluid is less than or equal to the determined value;   a pump configured to accept a flow of strong solution, increase the pressure of the accepted strong solution, and provide a flow of pressurized strong solution;   a generator coupled to a heat source, the generator configured to accept a first portion of the pressurized strong solution flow from the pump, extract at least a portion of the working fluid from the strong solution using heat extracted from the heat source, and provide both a flow of pressurized working fluid and a flow of weak solution;   a condenser coupled to a cooling medium, the condenser configured to accept the pressurized working fluid from the generator, decrease the temperature of the accepted pressurized working fluid by rejecting heat to the cooling medium, and provide a flow of cool pressurized working fluid;   a throttle configured to accept the flow of cool pressurized working fluid from the condenser and reduce the pressure of the cool pressurized working fluid so as to vaporize a portion of the cool pressurized working fluid thereby reducing the temperature of the fluid, and provide a flow of cold working fluid;   an evaporator coupled to an external cooling load, the evaporator configured to accept the flow of cold working fluid from the throttle, vaporize at least a further portion of the cold working fluid using heat extracted from the external cooling load, and provide a flow of working fluid;   an absorber configured to accept the flow of working fluid from the evaporator and the flow of weak solution from the generator, dissolve the working fluid in the weak solution to create a strong solution, and provide a flow of the strong solution to the pump.   
     
     
         21 . The power system of  claim 20 , wherein the heat source is waste heat from an engine.