Patent ID: 7171957
Filing Date: 2007-02-06
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. A compression ignition engine comprising: a control system comprising a processor for processing data including data indicative of engine load; one or more combustion chambers; an intake system for conveying charge air to the one or more combustion chambers; a fueling system for injecting fuel into the one or more combustion chambers; an exhaust system for conveying exhaust gases from the one or more combustion chambers; an exhaust gas recirculation system, comprising valves and heat exchangers in a flow control circuit, for controlling both recirculation of some of the exhaust gases to the intake system and temperature of recirculated exhaust gases; wherein a first branch of the circuit comprises a first of the valves and a first of the heat exchangers in series, a second branch of the circuit comprises a second of the valves in parallel with the first branch, and a third branch of the circuit comprises a second of the heat exchangers through which flow through the first branch and flow through the second branch are constrained to pass; and when a result of the processor processing data indicative of engine load discloses engine load in a low load range, the control system causes the fueling system to fuel the engine for operation by alternative diesel combustion and causes flow through the second and third branches, but not the first branch, when a result of the processor processing data indicative of engine load discloses engine load in a medium load range comprising loads greater than those of the low load range, the control system causes the fueling system to fuel the engine for operation by alternative diesel combustion and causes flow through the first and third branches, but not the second branch, and when a result of the processor processing data indicative of engine load discloses engine load in a high load range comprising loads greater than those of the medium load range, the control system causes the fueling system to fuel the engine for operation by conventional diesel combustion and causes flow through the second and third branches, but not the first branch.