A sensor system developed by researchers at Saarland University in Germany and a group of industrial partners can provide operators of combined heat and power plants (CHP) with continuous feedback on the state of the oil in industrial equipment.

The oil flows through a measuring cell where it is analyzed spectroscopically to record the condition of the oil. The researchers say the method offers numerous benefits: it is better for the environment, it lowers operating costs, and it simplifies maintenance scheduling.

Prof. Andreas Schütze (l) and Engineer Eliseo Pignanelli.The oil in the engines CHP power plants is changed at regular intervals, roughly every 1500 hours, researchers say, but in many cases the oil could have been used for longer.

Andreas Schütze and his team say that the technique puts a small measuring cell into the engine, through which oil flows while the engine is running. As a result, the quality of the oil can be continuously monitored and provide operators with a forecast of when the next oil change is likely to be due. This helps to enable maintenance work to be scheduled more conveniently and it eliminates the risk of engine damage from a sudden deterioration in the condition of the oil.

In the process, the measuring cell continuously monitors the chemical composition of the oil. The oil is irradiated with infrared light, and the light that passes through the oil is detected.

Combined heat and power (CHP) plants generate electricity and heat locally at the site where they are needed and thus offer a way of supplying heat and power independently.

The Saarbrücken sensor system can be installed as a standard component in CHP plants. In addition to being fitted in cogeneration systems, the sensor system can also be installed in industrial plants, wind turbines, machinery or even used in mobile equipment.