Engine inlet air cooling system and method

Abstract

A method of cooling inlet air to an engine includes pressurizing the inlet air during a first compression stage, and further pressurizing the inlet air during a second compression stage. Heat is transferred from the inlet air to a primary coolant liquid between the first compression stage and the second compression stage, and heat is transferred selectively, variably, or selectively and variably from the primary coolant liquid to a fuel of the engine.

What is claimed is: 
     
         1 . A method of cooling inlet air to an engine, comprising
 pressurizing the inlet air during a first compression stage;   further pressurizing the inlet air during a second compression stage;   transferring heat from the inlet air to a primary coolant liquid between the first compression stage and the second compression stage, and   selectively, variably, or selectively and variably transferring heat from the primary coolant liquid to a fuel of the engine.   
     
     
         2 . The method of  claim 1 , further including transferring heat from the primary coolant liquid to a secondary coolant liquid. 
     
     
         3 . The method of  claim 1 , further including;
 determining a temperature of the inlet air, and   varying the quantity of heat transferred from the primary coolant to the fuel of the engine as a function of the temperature of the inlet air.   
     
     
         4 . The method of  claim 3 , wherein the temperature of the inlet air includes a temperature of the inlet air after the first compression stage and before the second compression stage. 
     
     
         5 . The method of  claim 3 , wherein the temperature of the inlet air includes a temperature of the inlet air after the second compression stage. 
     
     
         6 . The method of  claim 1 , further including;
 determining the humidity of the inlet air, and   varying the quantity of heat transferred from the primary coolant to the fuel of the engine as a function of the humidity of the inlet air.   
     
     
         7 . The method of  claim 1 , further including;
 determining a temperature of the primary coolant, and   varying the quantity of heat transferred from the primary coolant to the fuel of the engine as a function of the temperature of the primary coolant.   
     
     
         8 . The method of  claim 1 , further including varying the flow of the primary coolant through a fuel cooled heat exchanger. 
     
     
         9 . The method of  claim 1 , further including varying the flow of the primary coolant through a fuel cooled heat exchanger bypass circuit. 
     
     
         10 . The method of  claim 1 , further including mixing the flow of the primary coolant exiting a fuel cooled heat exchanger with the flow of the primary coolant from a fuel cooled heat exchanger bypass circuit. 
     
     
         11 . An engine inlet air cooling system, comprising:
 a first compressor configured to pressurize inlet air,   a second compressor configured to further pressurize the inlet air, and   a cooling circuit including;
 a coolant heat exchanger configured to transfer heat from a primary coolant liquid, 
 an inlet air heat exchanger configured to transfer heat from the inlet air to the primary coolant liquid after the inlet air exits the first compressor and before the inlet air enters the second compressor, and 
 a fuel cooled heat exchanger configured to variably, selectively, or variably and selectively transfer heat from the primary coolant liquid to a fuel of the engine. 
   
     
     
         12 . The system of  claim 11 , further including;
 a primary coolant temperature sensor configured to generate a primary coolant temperature signal indicative of the temperature of the primary coolant,   a controller configured to generate a fuel cooling command signal as a function of the primary coolant temperature signal, and   a control valve assembly configured to vary the flow of the primary coolant liquid through the fuel cooled heat exchanger as a function of the fuel cooling command signal.   
     
     
         13 . The system of  claim 11 , further including;
 an inlet air temperature sensor configured to generate an inlet air temperature signal indicative of the temperature of the inlet air,   a controller configured to generate a fuel cooling command signal as a function of the inlet air temperature signal, and   a control valve assembly configured to vary the flow of the primary coolant liquid through the fuel cooled heat exchanger as a function of the fuel cooling command signal.   
     
     
         14 . The system of  claim 11 , further including;
 an inlet air humidity sensor configured to generate a an inlet air humidity signal indicative of the humidity of the inlet air,   a controller configured to generate a fuel cooling command signal as a function of the an inlet air humidity signal, and   a control valve assembly configured to vary the flow of the primary coolant liquid through the fuel cooled heat exchanger as a function of the fuel cooling command signal.   
     
     
         15 . The system of  claim 11 , further including a fan to direct a secondary coolant liquid through the coolant heat exchanger, the coolant heat exchanger configured to transfer heat from the primary coolant liquid to the secondary coolant liquid. 
     
     
         16 . An engine inlet air cooling system, comprising:
 an inlet air heat exchanger including a inlet air passage and a first primary coolant passage in thermal communication,   a coolant heat exchanger including a second primary coolant passage,   a fuel cooled heat exchanger including a fuel passage and a third primary coolant passage in thermal communication,   an inlet air circuit including a first compressor configured to pressurize inlet air, the inlet air passage, and a second compressor configured to further pressurize the inlet air, wherein the inlet air passage fluidly connects the first compressor and the second compressor,   a fuel circuit including the fuel passage, and   a primary coolant circuit including;
 the first primary coolant passage, 
 the second primary coolant passage fluidly connected to the first primary coolant passage, 
 the third primary coolant passage fluidly connected to the first primary coolant passage, 
 a fuel cooled heat exchanger bypass fluidly connected to the first primary coolant passage, and 
 a control valve assembly selectively fluidly connecting the second primary coolant passage to the bypass, and selectively fluidly connecting the second primary coolant passage to the third primary coolant passage. 
   
     
     
         17 . The system of  claim 16 , further including a mixing valve fluidly connecting the first primary coolant passage to the bypass and the third primary coolant passage. 
     
     
         18 . The system of  claim 16 , wherein the fuel circuit includes a cryogenic fuel storage container fluidly connected to the fuel passage. 
     
     
         19 . The system of  claim 16 , wherein the fuel circuit includes a fueling device fluidly connected to fuel passage. 
     
     
         20 . The system of  claim 16 , wherein the inlet air circuit includes an inlet air cooler fluidly connecting the outlet of the second compressor with an intake manifold of the engine. 
     
     
         21 . An engine system, comprising:
 an engine including an intake manifold, and a fueling device   a fuel source,   a first compressor configured to pressurize inlet air,   a second compressor configured to further pressurize the inlet air, the second compressor fluidly connected to the intake manifold, and   a cooling circuit including;
 a coolant heat exchanger configured to transfer heat from a primary coolant liquid, 
 a inlet air heat exchanger configured to transfer heat from the inlet air to the primary coolant liquid after the inlet air exits the first compressor and before the inlet air enters the second compressor, 
 a fuel cooled heat exchanger configured to selectively transfer heat from the coolant liquid to a fuel of the engine, the fuel cooled heat exchanger fluidly connecting the fueling device and the fuel source.