Colloquia

Summary

Industrial boilers play an important role in generating energy and steam in various sectors. In the Netherlands, a significant portion of the natural gas consumption is attributed to these boilers Due to climate change, there is a growing push to increase the sustainability of these systems. One approach is to blend hydrogen into the fuel, or replace it all together. In this context, the university is assisting the industry with acquiring the necessary knowledge to support this transition in the NWO funded project DYNAF.

One of the risks in boiler design are thermo-acoustic instabilities:  two-way coupling between acoustic waves and unsteady heat release rates. The effects can amplify each other, creating a feedback loop. If this effect is left unchecked, the pressure waves could cause mechanical failure or damage equipment.

Since the heat and pressure wave are coupled, accurately knowing the temperature inside the combustor becomes an important analysis tool in understanding and preventing these pressure oscillations. Traditional thermocouples have severe shortcomings for applications in these high temperature conditions. An alternative method of measuring the temperature of a medium is the use of sonic thermometry, as the
speed of sound in a gas mixture is directly related to its temperature.

In this assignment  a labscale ultrasonic thermometer was developed and tested, with the goal of applying this measurement technique in combustor conditions. Several pieces of hardware and measurement methods were tried to develop a procedure to taking accurate temperature measurements in an increasingly realistic enviroment.