Balance of plant in combined cycle power plant

The condenser is designed for receiving and safely condensing all steam flows, including steam flows from the steam bypasses and drains, where low temperatures and pressures maintain good efficiency in the Rankine process. The condensate is led to the condensate system.

A raw water system supplies make-up water to the main cooling water system which circulates to meet all the steam condensing and auxiliary water requirements of the power plant.

The cooling towers are designed to cool the heated water to the required design temperature when the steam turbine is operating at full guaranteed output.

These systems consist of an open cooling water circuit taking rejected heat via water/water cooled from a closed secondary cooling circuit. The coolant in the primary circuit is tapped off the main cooling water system.

Water treatment systems control the water intake, water quality and re-generation. The prime function of the water treatment system is to achieve a treated water quality in accordance with VGB guidelines or equivalent internationally recognised standards/guidelines, to meet the steam turbine quality requirements.

The dissolved non-condensable gases normally present in the condensate cause many corrosion problems. The de-aeration and storage functions, combined here in one vessel, are designed to remove such non-condensable gases as oxygen and carbon dioxide from the plant condensate, and any supplementary make-up water, to achieve the quality required.

The condensate has low conductivity and can be measured by KROHNE OPTIBAR DP flowmeters or OPTISONC 3400 ultrasonic flowmeters. Many tank levels in the condensate system need to be monitored and controlled. This can be achieved using OPTIFLEX 7200/ 8200 guided Radar level meters directly integrated into the storage tanks or via BM26 bypass level gauges which can incorporate a variety of different technologies such as TDR, FMCW, MLI, REED or limit switches, even in redundant configurations.