2003-08-07 - Hydrogen purity analysers from ABB Limited have been supplied to Innogy’s 2000MW Didcot ‘A’ Power Station to help maximise generator efficiency.
The four Analyze
IT Hydrogen Purity Monitors will be used to measure the concentration of hydrogen used to cool the generators during operation. Approximately seven times more thermally conductive than air, hydrogen is perfect for removing excessive heat, making it an ideal coolant for generator applications in the power industry. It is also considerably less dense than air, which helps to optimise generator performance by reducing windage losses caused by drag.
ABB’s AnalyzeIT Hydrogen Purity Monitors have been supplied as part of an upgrade and will replace existing Kent units installed for over 30 years.
Once installed, the monitors will help to ensure that the generators are running with as close to 100% hydrogen as possible. This is important because each percentage drop in hydrogen purity can lead to windage losses that can greatly reduce generator efficiency. A reduction of just 8% hydrogen purity on an 800MW generator, for example, could cost around £2,500 per day through reduced efficiency.
ABB's AnalyzeIT Hydrogen Purity and Purge Gas Monitor system meets ATEX as well as CENELEC EExia IIc standards for intrinsic safety.
The system uses two thermal conductivity analysers, suitable for installation in Zone 0 hazardous areas, to monitor the concentration of the hydrogen supplied to the generators. These analysers are linked to ABB 4234/500 series Power Supply Units, which must be installed along with the display unit in a safe area. By using two analysers in parallel, the system ensures there is always protection against the risk of one analyser failing.
In addition, ABB has also supplied 20 of its new AnalyzeIT Conductivity Analyser AX400 units to Didcot. Replacing previously installed Kent analysers, the AX400 units are being used to measure the conductivity of boiler feedwater and ensure that conductivity levels are maintained within the strict limits required for maximum boiler efficiency.
"We chose ABB for its ability to provide all the equipment we needed to help upgrade our existing installations", says Robert Brown, Instrument Team Leader, Didcot Power Station. "Once the hydrogen purity monitors are installed, we expect them to help us achieve and maintain maximum generator performance".