Fuel utilization

Abstract

Embodiments of the present invention provide a fuel supply system for combustion engines, whereby the temperatures of an oxidizer and fuel may be increased so that the temperatures approach but do not achieve an auto-ignition temperature for the fuel charge. The fuel charge may result in substantial improvements in fuel efficiency.

1 . A method, comprising: 
 adjusting the temperature of a fuel charge so that the temperature approaches, but does not achieve, an auto-ignition temperature;    inducting the fuel charge into a combustion chamber; and    initiating a combustion event to substantially auto-ignite the fuel charge.    
   
   
       2 . The method of  claim 1 , wherein the fuel charge includes an oxidizer component and a fuel component; and 
 adjusting the temperature of the fuel charge comprises heating the oxidizer component and/or the fuel component prior to inducting the fuel charge into the combustion chamber.    
   
   
       3 . The method of  claim 2 , further comprising controlling the heating of the oxidizer component and/or the fuel component to maintain a desired oxidizer-to-fuel ratio.  
   
   
       4 . The method of  claim 1 , wherein the adjusting the temperature of the fuel charge comprises increasing the temperature of the fuel charge to dilute the fuel charge.  
   
   
       5 . The method of  claim 1 , wherein the fuel charge includes a vapor fuel component.  
   
   
       6 . The method of  claim 1 , wherein initiating the combustion event comprises initiating a spark to substantially auto-ignite the fuel charge.  
   
   
       7 . The method of  claim 1 , further comprising adjusting the timing of the initiation of the combustion event to substantially auto-ignite the fuel charge at a desired crank angle based at least on characteristics of the fuel charge.  
   
   
       8 . The method of  claim 7 , wherein the characteristics of the fuel charge include homogeneity, temperature, combustion duration, and/or flame speed of the fuel charge.  
   
   
       9 . A method comprising: 
 during a first mode of operation: 
 inducting an amount of preheated fuel into a combustion chamber; and  
 combining an amount of exhaust-gas-recirculation with the amount of preheated fuel to substantially ignite the amount of preheated of fuel; and  
   during a second mode of operation: 
 inducting an increased amount of preheated fuel into the combustion chamber;  
 combining a decreased amount of exhaust-gas-recirculation with the increased amount of preheated fuel, the decreased amount of exhaust-gas-recirculation incapable of substantially igniting the increased amount of preheated fuel; and  
 performing a spark to substantially ignite the increased amount of preheated fuel.  
   
   
   
       10 . The method of  claim 9 , wherein the first mode of operation further comprises performing an initiation spark in addition to combining the amount of exhaust-gas-recirculation with the amount of preheated fuel to substantially ignite the amount of preheated fuel.  
   
   
       11 . The method of  claim 9 , wherein the second mode of operation further comprises, advancing the performing of the spark to occur sooner in a compression cycle of the combustion chamber.  
   
   
       12 . The method of  claim 9 , wherein the preheated fuel has been fractionated.  
   
   
       13 . The method of  claim 9 , wherein the amount of preheated fuel and the increased amount of preheated fuel are both mixed with an oxidizer, and the oxidizer-to-fuel ratio is maintained at approximately 14.7-to-1.  
   
   
       14 . A system comprising: 
 a vaporization chamber including a heating source to vaporize fuel;    an air conduit adapted to supply and mix air with the vaporized fuel; and    a controller to control the mixture of air and fuel to maintain a desired carbon level in an amount of combustion exhaust.    
   
   
       15 . The system of  claim 14 , wherein the controller further controls the mixture of air and fuel to maintain a desired air-to-fuel mixture.  
   
   
       16 . The system of  claim 14 , wherein: 
 the heating source is adapted to fractionate the fuel and/or increase the temperature of the fractioned fuel;    the air conduit includes an air heater adapted to increase the temperature of the air; and    the controller is adapted to control the increase in temperatures of the fractionated fuel and/or the intake air to maintain a desired air-to-fuel ratio.    
   
   
       17 . The system of  claim 16 , further comprising: 
 a mixer to combine the heated intake air and the heated fractionated fuel to form a fuel charge;    a combustion chamber to combust the fuel charge; and    a spark plug to perform a spark to substantially ignite the fuel charge, wherein the controller further controls a timing of the performance of the spark.    
   
   
       18 . The system of  claim 16 , wherein the controller further controls the mixture of the heated intake air and the heated fractionated fuel to maintain an air-to-fuel ratio of the fuel charge.  
   
   
       19 . The system of  claim 16 , further comprising a sensor to monitor at least one of oxygen content, temperature, ignition temperature, carbon content, air-to-fuel ratio, and/or density of the fractionated fuel and/or intake air.  
   
   
       20 . A method of combusting a fuel charge comprising: 
 inducting a prepared fuel charge into a combustion chamber;    initiating a flame front to ignite a first portion of the prepared fuel charge to increase the temperature and pressure inside the combustion chamber;    initiating auto-ignition of a second portion of the prepared fuel charge, as a result of the increase in temperature and pressure inside the combustion chamber; and    initiating subsequent flame fronts and/or subsequent auto-ignitions of the remaining portions of the prepared fuel charge to cooperatively and substantially combust the fuel charge.    
   
   
       21 . The method of  claim 20  further comprising adjusting the timing of the initiating of the flame front to cooperatively and substantially combust the fuel charge at a desired crank angle.  
   
   
       22 . The method of  claim 20  wherein the prepared fuel charge is fractionated.  
   
   
       23 . A method comprising: 
 diluting a fuel charge to be combusted in a combustion cylinder; and    adjusting the combustion of the diluted fuel charge to generate a desired power output based at least in part on characteristics of the diluted fuel charge.    
   
   
       24 . The method of  claim 23 , wherein diluting the fuel charge comprises increasing the temperature of an amount of fuel and an amount of oxidizer to generate a diluted fuel charge having an oxidizer-to-fuel ratio of approximately 14.7-to-1.  
   
   
       25 . The method of  claim 23  wherein adjusting the combustion of the diluted fuel charge comprises substantially combusting the diluted fuel charge at a desired crank angle.