Internally cooled internal combustion engine and method thereof

Abstract

An internal combustion engine is equipped with a water injector for cooling the internal combustion engine by a spray of atomized water into the intake track or combustion chamber prior to ignition. The atomized water spray may be in the intake manifold or directly in the cylinder. The water is injected at a volume of between a ratio of about 95% fuel to about 5% water and about 50% fuel and about 50% water. The temperature of the internal combustion engine is maintained at between about 95° C. and about 200° C. during operation.

What is claimed is: 
     
         1 . An internal combustion engine comprising:
 at least one cylinder, each cylinder having a combustion chamber, a piston, an air intake valve, and an exhaust valve, a mechanical compression ratio in each cylinder being greater than 12:1 and less than 40:1;   an air intake track in communication with each air intake valve;   an exhaust track in communication with each exhaust valve;   a fuel handling system with at least one fuel injector for injecting fuel into the combustion chamber or intake track, the fuel handing system providing an air to fuel ratio having a ratio of air to fuel (λ) greater than 1 and less than 7.0;   an ignition system for igniting the fuel in the combustion chamber at an end portion of a compression stroke of the piston;   a water injection system comprising a water injector for introducing an amount of water into the combustion chamber, and a water reservoir in fluid communication with the water injector, the water injector being arranged to inject a controlled amount of liquid water stored in the water reservoir into the combustion chamber or intake track; and   an external cooling system comprising a radiator and coolant, the external cooling system being configured to maintain a coolant temperature of between about 91° C. and about 200° C.   
     
     
         2 . The internal combustion engine of  claim 1 , further comprising:
 an exhaust gas recirculating (EGR) system for recirculating exhaust gases from the exhaust port to the engine intake; and   an EGR cooling system for cooling the recirculated exhaust gases by direct contact with a predetermined quantity of atomized water injected into the EGR track   
     
     
         3 . The internal combustion engine of  claim 1 , wherein the amount of water is in a range of between about 5% and about 100% with respect to the quantity of fuel injected. 
     
     
         4 . The internal combustion engine of  claim 1 , wherein the amount of water is in a range of between about 25% and about 100% with respect to the quantity of fuel injected. 
     
     
         5 . The internal combustion engine of  claim 1 , wherein the internal combustion engine is maintained at a temperature of about 130° C. during operation. 
     
     
         6 . An internal combustion engine comprising:
 at least one cylinder, each cylinder having a combustion chamber, a piston, an air intake valve, and an exhaust valve;   an air intake track in communication with each air intake valve;   an exhaust track in communication with each exhaust valve;   a fuel handling system with at least one fuel injector for injecting fuel into the combustion chamber or intake track;   an ignition system for igniting the fuel in the combustion chamber at an end portion of a compression stroke of the piston; and   a water injection system comprising a water injector for introducing an amount of water into the combustion chamber, and a water reservoir in fluid communication with the water injector, the water injector being arranged to inject a controlled amount of liquid water stored in the water reservoir into the combustion chamber or intake track; and   an external cooling system comprising a radiator and coolant, the external cooling system being configured to maintain a coolant temperature of between about 91° C. and about 200° C.   
     
     
         7 . The internal combustion engine of  claim 6 , wherein the amount of water is in a range of between about 5% and about 100% with respect to the quantity of fuel injected. 
     
     
         8 . The internal combustion engine of  claim 6 , wherein the amount of water is in a range of between about 25% and about 100% with respect to the quantity of fuel injected. 
     
     
         9 . The internal combustion engine of  claim 6 , wherein the internal combustion engine is maintained at a temperature of about 130° C. during operation.