Installing ABB ACS355 inverter drives to the oil injecting system has saved a UK coal-fired power station over £350k in oil costs.

To light the coal-fired boilers, the power station uses 36 oil injecting lances on each of its three boilers. Oil from the lances is blown into the boiler by fans at two rates – a high flow rate to light the coal and a low flow rate to sustain and support the burn.

The flame size is dependent on the oil-to-air ratio: too much air and the flame will blow out; too little may allow oil to enter the boiler and cause potentially dangerous combustion conditions.  The original DOL fan motors made it difficult to get the correct oil flow rate required.

As part of an energy saving programme, variable-speed drives to control the combustion air flow were considered.  The power station is a very challenging environment with a lot of coal dust and water, and an operating ambient of over thirty degrees Centigrade.

A total of thirty two ACS355 inverter drives from ABB UK with IP66 enclosures were installed on selected oil injecting lances.  The plan being to install a further sixteen drives dependent on achieving the required oil flow rate at specific points on the boiler.

The drives were set to run the motors at 50 Hz for the high flow rate used to light the boiler. This flow rate will normally be used for the first ten hours.  A 35 Hz speed is used to maintain a flow rate that sustains the burn. The duration of this can vary depending on the type and quality of the coal.

In addition to saving £350k on oil costs, the engineers anticipate further savings by using the inverters and in the case of future oil price increases.

Go to 999 Inverters ACS355 drives from ABB UK at discounted prices