Research On Performance Of Hydrodynamic Speed Regulation System With Variable-input And Constant-output

Shaft generator system is the device driven by marine engine when it has sparepower. This device can reduce the consumption of fuel and lubricating oil, decrease thecost of maintenance, prolong maintenance cycle and raise the utilization factor of cabinspace. As the ship electric progressing, the development direction of shaft generatorsystem is large capacity, high efficiency, high reliability and low cost.When the ship is voyaging, the speed and torque of the marine engine need to bechanged at any time in order to alter the power of the propeller to conform the conditionof ship sailing. This change is delivered to the shaft generator through the transmission,which will result in the instability frequency of electricity. The instability frequency ofelectricity is difficult to access onto the power grid. It is a very important issue to keepthe shaft generator running in working order. There are two ways to solve the problemrecently. One is speed compensation. Because of the inefficiency of using, the speedcompensation has been gradually eliminated. The other is frequency compensation.Due to the increasing capacity of the shaft generator system, the frequencycompensation become increasingly complex, costly and unreliably.In this study, a hydrodynamic speed regulation system with gear train andhydrodynamic torque converter with adjustable stator are presented. It is a system thatcan achieve variable-input and constant-output, which can keep the shaft generatorworking stably without frequency compensation and improve the reliability of the shaftgenerator system. Because of the hydraulic element, hydrodynamic speed regulationsystem can damp the vibration, resist the shock of speed changed, decrease the peakload and prolong the life of the system. This paper provides a new way for thedevelopment of shaft generator system and broadens the application range ofhydrodynamic transmission based on the research of hydrodynamic speed regulation system. It is meaningful in theory and application.This study is focused on hydrodynamic speed regulation system. The mainresearch work of the paper is as follow:（1）A new shaft generator system with hydrodynamic speed regulation systemis presented. The mathematical model of hydrodynamic speed regulation system andshaft generator are established. This system can achieve variable-input and constant-output by adjusting the angle of adjustable stators in hydrodynamic torque converterwith adjustable stator. According to the frequency of electrical equipment on the ship,the speed input of shaft generator and the speed output of hydrodynamic speedregulation system are determined. Hydrodynamic speed regulation system and itsinternal elements are designed.（2）Based on the characteristics of hydrodynamic speed regulation system, thepower flow of transmission is researched and the mathematical relationship betweencycle power and output power is analyzed. The differential gear train model ofmechanical transmission on hydrodynamic speed regulation system is established tosimulate the dynamic characteristics. The response of load transient is obtained.（3）The hydrodynamic torque converter with adjustable stator is designed. Itsinternal flow field is simulated under the different openings of adjustable stators andthe different speed of hydrodynamic torque converter by using CFD. The velocitydistribution of flow field and pressure distribution of adjustable stators are acquired.Based on the results of numerical simulation, the characteristic of adjustable stators isanalyzed.（4）Accordingtothestructureof hydrodynamictorqueconverterwith adjustablestator, the way of adjusting mechanism is determined, the mathematic relation ofadjusting mechanism and adjustable stators is acquired. Based on the numericalsimulation of the torque converter, the fluid-structure interaction analysis of adjustingmechanism is accomplished. The stress and strain affected by the fluid under thedifferent openings of adjustable stators and the different speed of hydrodynamic torqueconverter are obtained, which can be used to design the structure of adjustingmechanism and select the motor.