Title: Experimental Investigation of Effects of Coal Dust Contamination on
Accuracy of Wet-Bulb Temperature Measurements
Organisation: The University of Queensland
Duration: From 06 – August – 2012 To 09 – November – 2012
A hot work condition in underground mines reduces the safety and ability of both miners and machines to operate at their maximum efficiency. The wet-bulb temperature (WBT) measurement plays a significant role in the design of mine ventilation and heat management strategies. Temperature sensors used in underground mines need to accurately measure the wet-bulb temperature to ensure health, safety, comfort and productivity of miners. However, due to the underground environmental conditions, the wetted wick, which covers the current wet-bulb sensors, may be exposed to different types of airborne contaminants such as coal dust in underground coal mines. Any measurement errors caused by these contaminants result in inaccurate heat management decisions. This project is first to experimentally investigate the effects of different degrees of contaminations on wet-bulb temperature mismeasurements and hence, on heat stress analysis in underground mines.
Outcomes and Benefits:
The effect of WBT mismeasurements on the heat stress index and Air Cooling Power (ACP). It that any error in WBT measurements causes an error in the heat stress index.
It that there is a direct relationship between the amount of coal dust contamination and the WBT mismeasurement. This relationship was found to be slightly different for heating and cooling processes.
A general comparison between two WBT sensors with clean and contaminated wicks showed that there was a constant misreading of the WBT by the contaminated sensor. This mismeasurement in both heating and cooling processes.