Research On Improving Emergency Cut-off Valve Control System Performance

The Emergency Cut-off Valve is generally used as the emergency cut-off equipmentof the thermoelectric units in the thermal power plants and nuclear power plants in China.The property and the reliability of the system concern that the plants can operate normallyor not. Recently, the development speed of the emergency cut-off valve technology isfaster than before. The result is that the cut off time is shorter and fast cut-off system ismore reliable. But, the system also has some shortcomings. Such as, the valve cut offslowly and unsightly, the oil and gas’ backflow can’t be prevented effectively, the positionof the valve can’t be controlled in real time. Aiming at above problems, we design a servocontrol unit which is use the accumulator as the power source. The unit can shorten theemergency cut-off time and improve the sensitivity. At the same time, it realizes thereal-time and automatic control during the fast and slow closing process.After reading a large number of literatures and real situation, we design an servo unitof emergency cut-off valve. According to the systematic study, we introduce thecomponents and working principle of the servo control unit. On the basis of the workingprinciple, we use the accumulator as the power source and confirm the volume of theaccumulator and initial pressure. Based on the actual parameter, we build the AMESimsimulation model. At the same time, we divide the work into two situations, self-regulationsituation and emergency cut-off situation. Via the analysis, we come to conclusions asfollows: The system can complete the emergency cut-off task within0.3s. The system canrealize that it can adjust the opening at real time. The paper is based on failure rate topredict the reliability of the servo control unit.The model which is built in this paper is reasonable, and it can realize the simulationand analysis of the hydraulic system, and provide the reference to improve the system.