Wireless technology

At the Slough Heat and Power energy facility in the UK, wireless transmitters monitor changes in boiler condensate conductivity, detecting leaks that could cause boiler damage

SSE has extended the use of Emerson Process Management’s Smart Wireless technology at its Slough Heat and Power energy facility in the UK. The Rosemount Analytical wireless conductivity transmitters are being used to detect changes in boiler condensate conductivity which could be caused by cooling-water leaks in the turbine’s condenser. If left undetected, the contaminated feedwater will cause hydrogen embrittlement of the furnace tubes that will result in tube failures.

The 80MW combined heat and power (CHP) plant had previously relied on manual sampling and laboratory analysis of turbine condensate. However, this method caused delays in detecting leaks and as a result the boilers had to be shut down while repairs were made.

"Emerson’s Smart Wireless conductivity transmitters allow us to continuously monitor the condensate extract lines," said Emma Wilcockson, electrical, control and instrumentation technician at SSE. "If we detect a change in conductivity, maintenance can be scheduled before the problem leads to an unplanned shutdown or damage to the plant."

Emerson had previously supplied a Smart Wireless Starter Kit for the boiler house, and SSE’s excellent experience with this application was a major factor in selecting wireless for this latest project. In addition, the costs and time required to run power and signal cables to each instrument made a conventional solution impractical.

Emerson recommended the best positioning for the conductivity probes, transmitters and gateway, and SSE installed the Rosemount Analytical Model 6081C Conductivity Transmitters in the condensate extraction lines.

The conductivity transmitters send data to the PLC-based control system via a Smart Wireless Gateway. Emerson’s AMS Device Manager predictive maintenance software is used to manage the Smart Wireless network. With an established wireless network at the plant, "plug-and-play" technology meant that it was very easy and quick for SSE engineers to install and configure the new wireless conductivity devices in the turbine basements.

Despite the harsh environment of the turbine basement, which is surrounded by metal structures that can obstruct wireless signals, the wireless network was quickly established. The system has been operating for more than six months and during that time the transmissions between transmitters and the wireless gateway have been extremely reliable