节温器对发动机热系统动态性能的影响

The interplay between thermostat nonlinear dynamic characteristics and engine thermal system hysteresis complicates system transient phenomena. A mathematical model to predict the complicated operation process of the engine thermal system was developed. On the basis of the mass, momentum and energy governing equations for the whole thermal-fluid networks, the thermostat, radiator, engine and other components were described by lumped parameters. The model was solved numerically and the real-time simulation was achieved to analyze the thermal system transient phenomena in the engine warm-up process. The investigation results indicate that the allocations and temperature-response characteristics of the thermostat, including hysteresis offset, time resistance and etc, have great influences on the engine thermal system transient performance.