According to the nonlinear rotor dynamics theory, a dynamic model that approaches to the practical situation was established for two-span bearing-rotor system with nonlinear oil film. By means of numerical stimulation, the influence of nonlinear oil-film force on the response of rotor system's coupling faults was analyzed. The bifurcation and chaos behaviors of the system were studied under the different work conditions. Nonlinear response diagrams, such as phase plane plots, locus trajectory, as well as amplitude spectrum, were obtained. The complex motion types and their evolvement course of the periodic motion, quasi-periodic motion and chaotic motion were analyzed. The results show that the system of bearing-rotor has abundant nonlinear dynamic behaviors.

The ethanol rectification device is the plant in which 95% ethanol is thrice rectified to make it anhydrous ethanol. The process is a batch reaction, the control system uses PLC multi-loop of the series-wound adjustment, to improve the precision of control and the automation. The advantages such as flexible control of PLC, multiple functions, the convenient key technical parameters setting and the open-and-shut interface of the operating system etc. Will finally make it applied extensively in the ethanol rectification device.