Replacement of steam turbine drive with electric drive

Abstract

The intent of this project is to investigate the feasibility of replacing steam driven turbines in a sugar mill with electric motors. To do this it was necessary to firstly verify precisely what the task was that the existing drive was doing. In this case the steam turbine was driving a pump that delivered water to two bagasse fuelled boilers in a sugar mill. Also the task involved the investigation and delivery of improving the existing system. By analysing parameters of the current installation such as reliability, efficiency and suitability of the existing installation, a benchmark was created that we could measure any improvements against. After the plant requirements were determined, the new installation could be designed. Pump and motor sizing was done using flow, head and pressure measurements. Drawings such as Electrical schematics, P &IDs and mechanical layouts were then developed. The electrical and mechanical installation then followed. As part of the upgrade a programmable logic controller and HMI (Human Machine Interface) were programmed to provide better control and supervision of the process. After installation and commissioning, an assessment was carried out and the level of success of the project was determined. It was shown quantifiably that the capital expenditure was more than justified and that this process could be repeated in many of the remaining steam turbines to achieve similar improvements in efficiency, safety and reliability