Modeling and Control Strategy for Engine Thermal Management System

In order to study the influence of engine silicone oil fan clutch on the performances of engine cooling system under different control strategies, a model of engine cooling system for light truck is established. The working characteristics of the silicone oil clutch and the measured performance parameters of the cooling system components are taken into account in our proposed model. Modeling methods for different silicone oil fan control strategies are also given. Using the established model, the performance parameters under different vehicle speeds, such as coolant temperature of engine outlet and power consumption of cooling fan, are calculated and analyzed. The in-suite measurement of the engine cooling system is carried out to get the temperatures of engine coolant inlet and outlet from engine ECU. The model is validated by the comparison between the calculation and the measured results. Based on the established model, the working characteristics of different control forms of silicone oil clutch are analyzed, and an adaptive fuzzy PID control strategy is proposed for the controlled silicone oil clutch. Compared with the two-speed silicone oil clutch based on air temperature control and the electronically controlled silicone oil clutch based on PID controller control, the results show that the adaptive fuzzy PID controller established in this paper can reduce the power consumption of the cooling fan by 26.1% and 10.7% , if the vehicle runs under heavy-duty commercial vehicle test cycles (CHTC) .The modeling and analysis method in this paper can be used for the development and optimization of silicone oil clutch control strategy.