Deviations in superheated steam temperature were reduced by more than 50% by ADEX at the Cockenzie Power Station of Scottish Power.
ADEX was applied to the control of superheated steam temperature at Scottish Power’s coal fired power plant in Cockenzie, near Edinburgh. The objective of the project was to investigate the potential for improving plant efficiency through optimised control of the live superheated steam temperature entering the turbine, both under steady state and changing load conditions. The control action was to regulate the flow rate of attemperation spray water injected into the steam close to the inlet of the secondary superheater. It has been demonstrated that the control precision achieved by ADEX maintaining the steam temperature close to its setpoint resulted in maximizing the efficiency of the turbine and minimizing the risk of reducing the useful life of the pipework by reducing levels of thermal stress caused by excessive excursions and oscillations of steam temperature. The deviations from the setpoint in steam temperature were reduced by more than 50%.