The upgrade and characterisation of a heated two-tank system emulating typical fault conditions

Abstract

This dissertation covers the process of determining the shortcomings of the original heated two-tank system, as designed and constructed by P. Oberholzer [1], the improvements that were made, and the set of expanded features that were added. The dissertation also includes the characterisation of the fault emulation capabilities of the upgraded system. The original system’s effective operational range was analysed and quantified, specifically focusing on the limitations caused by component sizing. This also included an in-depth analysis regarding the effect control valves with different orifice sizes and flow characteristics had on the dynamic behaviour of the system. The system is then redesigned and upgraded based on the results of the analysis, mainly focusing on improving the control valve range and behaviour as well as the controllable temperature range. The control valve range is based on the utilised valve lift range for controlling the level and temperature of the system. The controllable temperature range is defined as the maximum temperature difference that the system can maintain between the two tanks as well as the maximum and minimum recommended temperature that can be maintained by the system. The effect of the component sizing redesign is then shown based on the upgraded system’s dynamic range. Lastly, the fault emulation capabilities of the upgraded system are explored. This is done by defining the faults that the upgraded system can emulate and then analysing and characterising these faults.