Reliability Analysis of Lube Oil in a Generator

Ekperi N. I; Gadin T. M; Akpuh D. C

Abstract

In this research work, we considered the best or better practices of maintaining lube oil balance in generator set by adopting a reliability analysis method. It was established that the running of the generator set for a long time and the heaviness of the appliances switched on upon the generator has been investigated to be a contributing factor for the reduction in the quality of the lube oil which influences the operational performance of the generator. The research work reveals constant failure of generator set when the quality of the lube oil is low and when allowed to run for as long as 400 hours. At the course of this research, a newly purchased generator set was allowed to run for 50, 100, 150, 200, 250, 300, 350 and 400 hours from the initial set time of the generator set, attained (1782 hrs). The results obtained revealed the order of magnitude of the failure rate as group 8 (400 hrs) > Group 7 (350 hrs) > Group 6 (300 hrs) > Group 5 (250 hrs) > Group 4 (200 hrs) > Group 3 (150 hrs) > Group 2 (100 hrs) > Group 1 (50 hrs) respectively. The functional parameters of failure rate were determined with respect to allowable load failure per optimum time interval, whereas the failures per year is a function of failure rate of each product upon the influence of load per annual hours per year. The corrective time per failure is a function of product upon the influence of load divided by total failure per year upon the influence of load. The gross margin evaluated the lost time per years of failed components with lost gross margin values in dollar ($) multiple with per hour. However, the scrap disposal cost per year for product upon the influence of load with scrap disposal cost of dollar ($) per incident upon the influence of load. Indeed, the breakdown maintenance cost was evaluated with the concept of gross margin cost multiple with scrap disposal cost divided by total breakdown maintenance. The results show that available power consumed reduces as time decreases from 50 hrs (15,872.5 Watts) to 400 hrs (9,612.5 Watts). The results show that energy utilized by the 20 kVA generator set increases from 50 hs (793.625 kWh) to 400 hrs (3,845.00 kWh). The results for reliability show a decrease from 50 hrs (51.81%) to 400 hrs (5.61%) while the unreliability increase from 50 hrs (48.19%) to 400 hrs (94.39%).