Underground Spot Cooling Installations—Context and Case Study

This paper presents engineering design and equipment selection for a successful temporary spot cooling installation used to support underground shaft sinking. The cooling system operated over a 22-month period from August 2021 to June 2023. The need for cooling was driven by the depth of shaft sink, which started from greater than 1900 m below surface. The system was subject to many of the common challenges preventing the widespread use of underground spot cooling, including limited process water and dewatering capability, heat rejection equipment placement in the path of blasting fumes, limited airflow quantity for heat rejection, and layout constraints due to the existing and upcoming mine services installations and construction. Use of hybrid cooling towers allowed for increased heat rejection capacity from evaporative cooling while maintaining a fully closed-loop condenser water circuit. Skid-mounting of all components allowed for easy placement and relocation. Use of HDPE piping lashed to existing ground support allowed for maximum layout flexibility and minimized installation time. Performance, operational features, and additional lessons learned, including feedback from operations personnel, are shared.