Performance Evaluation of a Micro-Steam Turbine Powered Electric Generator under Changeable Bed and Drive Mechanisms

Abstract
Machines are growth engines of the economy; each sector of the economy achieves its demand by the use of the machine. They are installed in various establishments for the purpose of using them to perform certain functions or others. However, as a result of the kind of forces, dynamic and static loads, they transmitted to their adjoining surroundings when used, they are often mounted on supporting structures, foundations or a combination of them to achieve adequate or appropriate safe operation and stability. When a machine is operating, it is subjected to several time-varying forces and as a result of which it tends to exhibit vibrations. In such a situation or process, a certain quantity of this force is transmitted to the foundation, which could undermine the life of the foundation and also affect its performance and the operation of any other machines on the same foundation. Hence, it makes sense to minimize this force transmission. This research aimed at developing an adjustable steel-framed structure for supporting the major components of a 5.0 kW micro-steam power unit (steam, turbine and alternator) and evaluating the performance of the unit with or without the vibration isolator when they are axially connected with flexible flange coupling or transversely connected with sets of belts and pulleys, in succession, respectively. The results showed that reduction in the force transmitted to the supporting structure occurred when the vibration produced by the unit is isolated from its base by the use of a vibration isolator, maximum reduction of 99.95% achieved when axially coupled and 99.91% when transversely connected with belt and pulley system. The results also showed that better performance would be attained when the steam turbine is axially coupled to the alternator than when connected with belt and pulley; The maximum voltage of 52 V and speed of 1000 rpm at 77 dB sound level attained with coupling connection, and voltage of 20 V and speed of 752 rpm at 75 dB with belt and pulley connection.