Power Generation Turbines

Types of Turbines Steam Combustion generates steam which turns turbines Gas Combustion creates power which turns turbines Combined Cycle Gas first, then exhaust creates steam

Steam Turbine

Managing the Health of Fire Resistant Steam Turbine Electrohydraulic (EHC) Control Oils Ken Brown, Utility Service Associates  The Electrohydraulic control (EHC) system is responsible for the critical task of governing steam delivery to turbines that drive electric generators in a power plant. Historically mineral oil-based fluids. Increasing steam temperatures (500°C to 550°C) and hydraulic fluid pressures (1,500 psi or 10 bar) demand the use of fire-resistant fluids to assure safe and reliable operation. Phosphate ester-based hydraulic fluids are the most common fire-resistant EHC fluids in use today. Phosphate ester fluids offer higher flash and fire points than mineral oils, and most importantly, they self-extinguish and are less likely to spread flaming streams or burning pools of oil.

Gas Turbine

Turbine Oil Functions Lubricate journal and thrust bearings Provide efficient cooling Prevent sludge Prevent Corrosion Sometimes hydraulic and gear

Oil Characteristics Viscosity Viscosity Index Demulsibility of Water Higher Speeds (>3,000 RPM) need ISO 22-32 Lower Speeds (>3,000 RPM) need ISO 32-68 Viscosity Index Min 95 Max 115 Demulsibility of Water Steam Leaks Condensation in reservoir Faulty cooling systems Oxidation Stability RPVOT Highly refined base oils

ASTM D2272 RPVOT Significance and Use 4.1 The estimate of oxidation stability is useful in controlling the continuity of this property for batch acceptance of production lots having the same operation. It is not intended that this test method be a substitute for Test Method D943 or be used to compare the service lives of new oils of different compositions. 4.2 This test method is also used to assess the remaining oxidation test life of in-service oils.

ASTM D943 TOST Significance and Use This test method is widely used for specification purposes and is considered of value in estimating the oxidation stability of lubricants, especially those that are prone to water contamination. It should be recognized, however, that correlation between results of this method and the oxidation stability of a lubricant in field service may vary markedly with field service conditions and with various lubricants. The precision statement for this method was determined on steam turbine oils. Turbine Oil Stability Test

Failure Modes Foam Rust and Corrosion Oxidation Air Intake from pumps Hi return pressure Can damage pumps Rust and Corrosion Water contamination Oxidation Temperature Metal contaminants

System Flushing and Filtration Initial Charge High velocity Filtration to ISO 17/16/14 Heating and cooling cycles Recharge Use flushing oil Vibration of lines and temperature cycling

1-5 year Oil Life Suitability for Continued Use (Annual) Viscosity ASTM D445 RPVOT ASTM D2272 Water by Karl Fischer Titration ASTM D1744 Acid Number ASTM D664 ISO Cleanliness Code 4406 Rust ASTM D665 A Demulsibility ASTM D1401 Foam ASTM D892 Sequence 2 ICP Metals

Greater than 4μm / Greater than 6μm / Greater than 14μm Filtration Clean Oil decreases the lifetime operation expense of a piece of equipment An ISO code is a set of three reference numbers separated by slash marks and refer to the number of particles of certain sizes in 100 milliliters of a fuel or oil. Greater than 4μm / Greater than 6μm / Greater than 14μm ISO 22/21/18 What does it mean?