Modern cooling fan arrangements in power stations are typically arranged in groups of eight or more, facing vertically on raised platforms and driven through a motor and gearbox combination. Gearbox failure is common, so the trending of gearbox vibration levels is essential for proper inspection and maintenance planning. Providing shutdown protection in the event of excessive vibration is also a key requirement for minimising damage in the event of fan blade failure.
Sensonics’ DN2601 dual vibration monitor fulfils both these requirements and has now been installed at EGAT’s Wangnoi power plant in Thailand, where there are three 600MW combined cycle blocks, each with eight cooling fans. A single DN2601 is used to monitor each fan in combination with ICP type accelerometers, providing warning and shutdown alarm facilities.
The DIN rail mountable unit provides a local display of vibration level as well as a buffered transducer output to assist with more detailed fault analysis using a portable instrument. Installed and commissioned by Sensonics’ Thailand partner Advance Siam Tech Co in 2007, the system is now providing valuable fan condition monitoring data to assist the station in maintaining high levels of availability and efficiency.