Methodology Development for Lubricant Selection for Steam Turbine Bearing Using GTA

Abstract

Lubrication of two rubbing surfaces is required so that wear and tear is minimum. There are a lot of additives used to improve the lubricity of the lubricants. At present steam turbines are used to generate electricity from coal. A lot of lubricant is supplied to turbine bearings so that friction is minimized and also the wear and tear also. A lot of manufacturers are producing lubricants with different properties. In the present work properties are identified and a suitability index in correspondence to these properties for different lubricants is evaluated. All the nine properties of lubricants affected suitability index are identified and their interdependence is also established. Performance evaluation of a lubricant necessitates to consider the inheritance of lubricant characteristics and the solution is near to real time situation when their interdependence is also considered in the modeling. For a solution near to real time situation inheritance of characteristics along with interdependence is incorporated with the help of Graph Theoretic Approach (GTA), as explained in manuscript. GTA results into an index representing the suitability of nano-particle added lubricant. From the results it is found that highest index value is 1. Lowest index values for different characteristics are found to be 0.3478, 0.3091, 0.2845, 0.3568, 0.3295, 0.3865, 0.3547, 0.3285 and 0.3945. The proposed methodology is explained with the help of an example