Browsing by Author "Randewijk, P. J."

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    Performance evaluation of a centrifugal pump system under variable speed operation
    (SAIEE, 2013) Kuhn, C.; Randewijk, P. J.
    ENGLISH ABSTRACT: The aim of this research project investigates the performance of a centrifugal pump system under variable speed operation. Operating a pump under variable speed operation brings the affinity laws into play. These equations were firstly investigated before it was applied to the overall investigation of pump performance. Distinction is made between three types of systems, a system with high static head (lift system), the second system is a high loss system with no- or little static head and the third is a mixed type system. The “correct” affinity laws were then used to apply to a system with a minimum pressure requirement. The theory proved accurate and was confirmed by practical findings. It has been found that both the pump and the VSD experience a slight drop in efficiency for small changes in speed. A maximum of 5% drop occurred in the efficiency of the pump for a 30% reduction in speed. Further reductions in speed resulted in a more rapid drop in efficiency.
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    Smart home : energy management system for demand side management
    (2014-12) Du Plessis, D.; Randewijk, P. J.
    With South Africa’s energy grid currently under severe pressure due to a lack of planning, electricity prices have escalated. This has forced consumers to look toward finding innovative ways to reduce their consumption. The aim of this research project was to create a system that assists in the reduction of household power consumption by simplifying the process of power saving. This is done by enabling consumers to remotely monitor and control their household devices. To achieve this goal, a power management system was designed that consists of a Beaglebone black, the main electronic controller, and a circuit for measurement and control. The measurement circuit measures the power consumption, it is then sent to Trintel’s SMART Platform enables users to remotely monitor and control the devices by using a web-based interactive graphical user interface.