Steam turbines of thermal power plants are installed in such a way that packing ring surrounds the entire turbine rotors in order to reduce the amount lost due to a leak of steam and to improve performance. However, the conventional packing ring cannot affect positively fluid velocity of the direction of steam, so it does not have the power to reduce vibration of the rotor. In this research, a study was conducted to reduce it by lowering the rotational speed of steam in the rotor. Anti-swirl teeth which changes rotational speed of steam into axial speed of it, designed in front of the conventional packing rings, and their numbers, twist angles. The characteristics of the rotor and the anti-swirl teeth were chosen as design factors to reduce vibration of the rotor. Through the finite element, the improved packing ring designed with the optimal anti-swirl teeth was developed.
Oil deflector prevents oil leakage that occurs in thermoelectric power plant at operating lubricant facilities. Vibration of rotating rotor-induced wear of aluminum tooth in existing oil deflector leads to oil leakage as well as life shortening of the tooth. In this study, an advanced oil deflector was developed for shock absorption and prevention of wear by decreasing clearance (from 0.5 mm to 0.2 mm) between rotor and tooth to minimize oil leakage, and by replacing 2 aluminum teeth in outmost of the oil deflector with hi-performance seal made of engineering plastic. The CFD results were compared between advanced vs. existing oil deflector to determine the amount of oil loss. Structural safety was verified through impact analyses according to the three kinds of engineering plastics, considering cost efficiency, and optimal material of hi-performance seal was chosen.