State of the art of technical background and practicality of pressure balance pipes for pumped storage turbine

Abstract

Abstract Pressure balance pipe is an important technical solution for the internal pressure balance of pump turbine and is widely used in pumped storage power units. This article systematically explains the application of pressure balance pipes in pump turbines, and sorts out three typical pressure balance application methods: the external pressure balance pipe structure balances the external side of the upper wearing ring and the lower wearing ring, the internal pressure balance pipe structure balances the internal side of the upper wearing ring and the draft tube, which improves the axial water thrust distribution of the unit and avoid uneven distribution of the axial water thrust on the runner. The spiral case pressure balance pipe realizes the control of water ring flow in the vaneless area under the synchronous condenser mode and pressure water by balancing the pressure of the spiral case and draft tube. For the above three structures, the current research progress, main problems and future development directions are elaborated.