A METHODOLOGY FOR EVALUATING FIELD PERFORMANCE AND EMISSIONS OF A GAS MICROTURBINE BASED COGENERATION SYSTEM

Abstract

Due to its high economic impact, when a new technology is handed over from manufacturer to customer, the contractually fixed guarantees and specifications have to be proven. Besides guarantees concerning environmental tasks, such as flue gas emissions, the availability and performance data of the new technology are the key issue. Field performance usually lacks very accurate measuring equipments and stable measurement conditions, as in many manufacturer testing laboratories. In this work a methodology was developed to evaluate performance and emissions under field conditions, together with a critical analysis of the resulting uncertainty of the main parameters, which are representative of the system performance, which was also detailed. In order to overcome field measurement difficulties, a methodology was used to measure combustion air flow rate from emission and gas flow rate measurements. The evaluation procedure was demonstrated by testing a microturbine based cogeneration system, which comprises a microturbine, a heat recovery system, and a steel storage hot water tank, providing electrical energy to Pontifical Catholic University of Rio de Janeiro grid and thermal energy for heating domestic water in cogeneration to its gymnasium showers. Data were acquired at carefully chosen stable test periods in which the gas microturbine was setup to produce electrical energy at nominal power outputs of 100, 75, 50 and 25% of maximum load. In addition, this paper presents an economical analysis for the system, which operates during peak hours (17:30 to 20:30) from Monday to Friday.