Experimental analysis on dynamic performance of refrigeration systems in a deep gold mine

Abstract

With the increment of depth of gold mining, the heat damage has become more and more serious and thus the thermal management systems of refrigeration and ventilation becomes essential. Dynamic performance is of great significance for the stability of system control and energy conservation. This paper proposes a thermal management system for the deep gold mine and builds an experiment platform, which fully utilizes the existing cycle air system. The system includes chilled water loop, intermediate loop and cold water loop. The dynamic response of the system is studied experimentally. The results show that rising and falling steps of the flow rate have similar effects on the system but the response time on the rising step is shorter. The response time of chilled water loop is 750 s for increasing by the step change of frequency and 1120 s for decreasing step change of frequency respectively. The total heat exchange of the air coolers increases from 6.93 kW to 7.31 kW during the rising step, and drops from 6.91 kW to 6.51 kW during the falling step. The response time of increasing and decreasing of pump of the intermediate cooling loop is 320 s and 403 s respectively. The total heat transfer rate of the system has no obvious change. Similarly, the response time of the cooling tower loop is 363 s and 1133 s. The total heat transfer rate of the system has no significant change. The research gives the response characteristic of step changes, which improves the stability of systematic control and energy conservation.