Ecoanalysis of Variable-Speed Drives for Flow Regulation in Pumping Systems

Abstract

Electronic variable-speed drives (VSDs) can produce large energy and environmental savings in variable-load variable-speed applications when compared with other conventional technologies. There are a very large number of applications (e.g., fluid motion, materials handling, and materials processing) which would benefit, both in terms of process improvement and energy savings, through the use of speed control. Previous studies have shown that the variable-flow fluid motion applications (pumps, fans, and compressors) have the largest savings potential. In this paper, an ecodesign analysis of two different technologies for the flow regulation in pumping systems - constant-speed pump with an output throttle valve (motor directly fed from the line) and variable-speed pump without an output throttle valve (motor fed by a variable-speed drive) - is presented. A European standard methodology for the ecodesign analysis of energy-using products is used in this paper. This paper includes a comparative analysis of the environmental impacts and life-cycle costs. The identified large environmental benefits on top of the energy savings provide a strong argument for an increased use of VSDs. The presented analysis is of major importance for industrial electronics manufacturers, designers, and users, widening their awareness to the importance of taking into account the energy and environmental issues when evaluating different system design options.