The Effect Of Tip Clearance Seal On The Aerodynamic Performance Of TRT Turbomachinery

With the development of economy,the consumption of energy is increasingly growing. To reduce the energy consumption and the pollution to the environment, a key measure is sustainable recycling use of energy. The TRT device is an energy-saving and environmentally friendly device. The TRT turbine is the main part to transform and recycle energy. The TRT turbine is limited by the energy of working fluid to transform and recycle energy, so the output power is also restricted. To improve the TRT turbine's efficiency and utilization, it's important to make full use of the energy in the turbine and reduce the loss in the channel.This paper researches on TRT turbine, and uses the clearance seal to restrain the leakage flow and improve the performance of turbine. This paper uses clearance seal to both stator and rotor of the tow-staged turbine by CFD numerical simulation. Analyzed the flow field structure, the velocity distribution, the loss origin and the effect of leakage to main flow and downstream in detail. Meanwhile studied the effect to the turbine's performance and seal's efficiency at different rotational speed and clearance height.The result shows that trapezoidal labyrinth seal is more effective for TRT stator. When in small clearance, the efficiency and the flow rate of the turbine improve differently at different rotational speed, meanwhile the leakage decreases greatly. When in large clearance, the effect of labyrinth seal is outstanding, the efficiency improves a lot and the flow rate and the power improve differently, meanwhile it controls the leakage best. For rotor, oblique labyrinth seal is more effective. When in small clearance, the performance of the prototype is better. The performance of the turbine can be hardly improved with rotor seal at designed rotational speed. When at low rotational speed, the performance of the turbine improves obviously with rotor seal. While the flow rate and the power stay the same. Compared with the performance in small clearance at designed rotational speed, the efficiency and the flow rate of the turbine in large clearance improve a little. In general, the effect of seal on stator is more obvious.