Pumped-storage plant with Francis turbine

Pumped storage hydroelectric plants use hydroelectric power to store electricity in periods both where demand is low, but also in periods where excess energy is being generated from other energy sources (such as windpower). These plants use natural or man-made reservoirs. Some of the pumped storage plants have natural inflows to the storage reservoirs, and thus are a net energy producer. The gross head of pumped storage plants ranges from 30 to almost 400 meters. Hydroelectric turbines of the reversible type convert the kinetic energy into electricity, or vice-versa. Water levels are controlled by weirs, and the water flow via the spillway and by valves integrated into the penstock. Penstocks can be buried as part of a dam or can be regular pressure pipes.

Level measurement and the precise forecasting of the upstream and downstream water body is essential for safe and efficient operation of the power plant. Installed at multiple points of the upstream and downstream water body the contactless OPTIWAVE 5200 FMCW radar level transmitter accurately and reliably measures water level. OPTIBAR DP7060 C differential pressure transmitters are used to monitor the pressure drop across the intake grating, within the penstock and across the hydro turbine. KROHNE OPTISONC ultrasonic inline flowmeters can be factory calibrated and cover a diameter of up to 3.000 mm. Other clamp-on and hot/ cold tapping versions are available for bigger sizes, for installation on site onto existing pipework. OPTIMASS 1400 Coriolis flowmeters with entrained gas measurement has been proven to be a reliable option for turbine bearing lubricant flow measurement even where there is some occurrence of gas, enabling a reliable lubricant supply to be monitored and maintained. The sophisticated KROHNE Penstock Leak detection system (PLDS) is based on several different field proven leak detection models. It produces zero false alarms and triggers emergency shutdown in case of pipe rupture or any turbine over-speeding, plus has also a low level leak detection capability. It can be used on the data from existing flowmeters and takes into consideration the characteristics of the different flowmeters installed.