Development of a Guideline for Field Testing of Gas Turbines & Centrifugal Compressors
Field testing is often conducted to verify the performance of centrifugal compressors and gas turbines at site conditions. The challenge in field testing is to obtain accurate and representative performance results from data that is measured under difficult conditions and varying site-specific requirements. Under a program funded by GMRC, Southwest Research institute has developed a comprehensive field test guideline for field testing of centrifugal gas compressor and gas turbines. This guideline recommends best practices for testing of gas turbine power and efficiency and centrifugal compressor power, head, flow and efficiency. Guidelines are based on recommendations from industry experts, existing public domain literature, and analysis of instrumentation, data acquisition, observed uncertainties, and performance calculation methods. It is anticipated that the guideline would become a reference that is widely acceptable for most OEMs and gas turbine users. This paper discusses the critical issues of the field test guideline, including pretest planning, test instrumentation, test setup and the determination of test uncertainty. The use of test uncertainty to assess the quality (and validity) of the field test results is also discussed. The paper presents the recommendations on ideal versus non-ideal installations and the impact of installations on test uncertainty. Equations of state, instrument installation best practices, pretest requirements, and data interpretation are also discussed. A widely accepted field test guideline will assure that field test performance results and associated uncertainties are clear, well defined, and fairly interpreted.