On-Field End-of-Life Filters Fouling Survey of Two 260 MW Gas Turbines

Abstract

Abstract. The performance and lifespan of gas turbines can be severely affected by airborne contaminants in the atmosphere. Natural and anthropogenic sources, combined with the machine's operating condition, determine the characteristics and intensity of contamination. Microsized particles ingested by compressor units can adhere to the blades, leading to performance deterioration, a phenomenon known as compressor fouling. Multistage filtration systems are crucial in mitigating the contamination severity at the intake of land-based units. High-efficiency media filters are commonly installed in the last stages to remove smaller particles from the airflow. However, the filter's exposure to contaminants leads to an increase in pressure drop, and consequently, maintenance operations have to be accurately scheduled to prevent excessive efficiency reduction. This work presents a detailed analysis of the contamination at the filter section of two 260 MW land-based units operating in different environments. The investigation comprises the on-field detection and collection of deposits from the two filter stages. The composition of the deposits was characterized from chemical, physical, and mineralogical perspectives. High-resolution imaging using optical and scanning electron microscopy (SEM) provided detailed morphological insights. In addition, X-ray powder diffraction (XRPD) analysis identified the crystalline phases present in the particulate. The findings dive into the deposits' structure, morphology, and chemical composition for both filter stages. At the same time, the dust particulate was interpreted concerning the surrounding environment based on the mineralogical examination.