Evaluation of Gas Turbine Reliability Effects Using the Sustainable Capacity Methodology

Abstract

The reliability of gas turbine driven compressor units is a major factor in the ability of a pipeline system to satisfy delivery or service requirements. However, despite it’s importance, unit reliability is not typically considered in design or operations. At Nova Gas Transmission Ltd (NGTL), a reliability evaluation methodology, referred to as Sustainable Capacity, has been developed to quantify service expectations through the explicit consideration of the effects of gas turbine reliability. The methodology, which has been adapted from one widely used in the electric power industry, is based on the representation of the load and capacity processes with statistical models. Time-series representing simultaneous load and capacity profiles are generated and evaluated to determine reliability expectations. A cost-benefit methodology which recognizes the variation in the value attributed to pipeline reliability by individual customers is also used to assess the economic efficiency of any proposed system modification. Although developed as a system design tool, the Sustainable Capacity methodology can also be used to quantify the value of gas turbine maintenance strategies provided the effect on unit reliability can be quantified.Copyright © 1997 by ASME