Thermal Management on Small Gasoline Engines

Increasingly stringent CO2 emission standards have been legislated; in part to encourage OEM's to develop more efficient propulsion systems. These development efforts have typically focused on improving steady state operation, but recently there has been increased interest on the improvement potential during dynamic behavior. In particular the warm-up behavior of combustion engines is a field of increasing investigation. This warm-up behavior is especially pertinent in Europe, where customers tend to drive shorter distances, and the New European Driving Cycle (NEDC) reflects this driving pattern. The desire to influence this warm-up behavior is typically referred to as thermal management.

Thermal management may be considered as “heat brokering” where the optimum flow of heat is to be decided, e.g. take heat from exhaust or coolant and feed it to coolant or oil. The goal is to reduce fuel consumption by achieving the most efficient warm-up of the powertrain. This paper will review the results of systematic testing and optimization of thermal management on small four cylinder engines. It will also review the potential for fuel consumption reduction through the use of heat storage devices.