Connah’s Quay Power Station in Wales has installed luminescent optical dissolved oxygen (O2) monitoring technology into its boiler system.
An Orbisphere K1100 sensor from analytical instrument manufacturer, HACH, now monitors dissolved O2 continuously in the power station’s boiler water feed, leading to minimised maintenance and calibration.
The instrument’s tip is coated with a luminescent material which is activated by blue light from an internal LED. The tip then emits a red light throughout the water, which is proportional to the dissolved O2 that is present, and measures both maximum intensity and decay time.
As a result of these advantages, we plan to replace all of our dissolved O2 monitors with the optical technology from HACH
Additionally, an internal red LED provides a reference measurement before every reading in order to maintain sensor accuracy.
The tip can be changed quickly and easily and the sensor only requires a zero-point calibration once a year with an O2-free gas, such as nitrogen (N2).
Bill Smith, Plant Chemist, explained, “The HACH optical dissolved O2 monitoring system is a good example of how new technology is helping to meet the demands of a changing energy sector by lowering operational costs and improving response time, accuracy and reliability.”
“As a result of these advantages, we plan to replace all of our dissolved O2 monitors with the optical technology from HACH.”
The plant contains four boilers which are fed from an exchange water treatment plant, and in order to prevent corrosion, this water needs to be de-aerated and pH-balanced.
Dissoved O2 monitoring ensures that this is achieved by keeping levels below 10 parts per billion (ppb). An automatic alarms sound in Connah’s control room if levels reach a limit of 20 ppb.
HACH optical monitoring systems are typically used in the power, water, wastewater and food and beverage industries.
Connah’s Quay, commissioned in 1996, is a combined cycle gas turbine power station near Deeside, UK, and generates an overall capacity of 1420MW, which is enough to power half of Wales.