Energy Savings From Electrification of Cooling System

Abstract

The cooling system is essential for creating suitable ambient for optimal performance of the engine and a healthy operating temperature to achieve high efficiency. Reaching the desired engine operating condition earlier will not only improve the life span of the engine but also improve the fuel efficiency and reduce environmental pollution. In conventional cooling systems, where the pump is always mechanically connected to the crankshaft, the optimum cooling efficiency of the engine is limited. In fact, the coolant circulates in the engine even when cooling is not desired, and this leads to extended engine warm-up time. Decoupling the pump from the crankshaft and driving the pump with electric motor, the cooling process can be controlled efficiently. The pump is then used only when required. A simple Pulse Width Modulation (PWM) controller with variable duty cycle has been adopted to impose the forced convention flow using a pump. The result of the simulation of the electrically driven pump reported here has been obtained for New European Drive Cycle (NEDC) and shows the possibility of saving about 3% of fuel during the homologation cycle compared to mechanically coupled pump. In addition, the engine operating temperature can be reached seven minutes (7mins) earlier in idling condition, corresponding to about 46.5% fuel saving with respect to the conventional cooling system.