Pressure Pulsation and Suppression Method Research of Electro-hydraulic System on Turbine
|School||Central South University|
|Keywords||Electro-hydraulic control system Closed chamber Pressurefluctuation Damping Proportional control|
In the power industry, the turbine is widely used in conventional thermal power plant and nuclear power plant, to drive the electric generator to produce electric energy. Electro-hydraulic control system is one of the most important parts of turbine, so the stability and reliability of it will directly affect the safe running of the unit. In a nuclear power plant, low-frequency but high-amplitude pressure impact, which not only cause the vibaration and the noise, but also affect the the normal and safe running of the unit, exists in the hydraulic part of its Electro-hydraulic control system. In this paper, pressure pulsation and suppression methods of the electro-hydraulic control system are studied. The main research contents are as follows:(1) The present situation of pressure fluctuation and electro-hydraulic control system is discussed. Based on the principle of power control system, which is proportional control system with a damping before the proportional valve, the significance is clarified by comparing with the proportional control system without damping.(2) Based on the principle of closed chamber dividing, the system is divided. Influence of damping on the pressure of the system is analyzed in proportional control system with damping before the valve. Through the contrastive analysis of pressure fluctuation with the system without damping, the main reason, the exsistance of the damping before the vavle and the diameter is unreasonable, that cause the large-amplitude pressure pulsation is clarified.(3) According to the causes of pressure pulsation, improvement measures, appropriatly increasing the damping diameter before the valve, changing the mounting position of the damping before the valve, using rubber hose instead of corrugated metal hose, are put forward, and the feasibility is analyzed.(4) AMESim simulation model of power hydraulic system is built, and the simulation parameters of each part are determined. By comparing the attenuation effects and influence on the performance of the system of three improved measures, the optimum pressure pulsation attenuation measure, changing the position of damping, is clarified.(5) By appling the improvement measures to an electro-hydraulic control system, the feasibility of improvement measures mentioned in the paper is verified.