Detecting disturbance of uniformity of a nitrogen and CO2 mixture in an acoustic tube

Abstract

Power engineering technologies have a considerable negative impact on climatic changes. Electricity generation in Poland is based on a continuous development of coal technologies which now need to satisfy increasingly strict ecological requirements. In order to meet these requirements, extensive scientific research is being pursued in the field of CO2 separation to stop the unfavourable trends in climatic changes caused predominantly by emissions of greenhouse gases, CO2 in particular. The research results still have not indicated decisively which separation technology should be selected and efforts are continuing to find new methods .This paper presents preliminary results of measurements of the disturbance of the nitrogen and CO2 mixture uniformity inside a thermoacoustic tube. The measurements were performed in a tube with an adjustable length, fitted with an acoustic inductor which made it possible to generate a standing wave. Transversely to the tube axis, a detection path was placed to identify disturbance of the CO2 and nitrogen contents. The tube was filled with an originally uniform mixture of nitrogen and CO2. An acoustic standing wave was induced inside the tube and the readings of the mixture uniformity disturbance detection system were recorded. More data were recorded from an inside measuring microphone that allowed detection of the standing wave. The gathered results were then processed numerically. The computations resulted in a series of curves in the time and frequency domains, illustrating the mixture behaviour inside the tube.