Why is proper lubricant selection critical for the longevity of hydraulic components in WECs?

Proper lubricant selection is critical for the longevity of hydraulic components in Wave Energy Converters (WECs) because the lubricant performs several essential functions. First, it reduces friction and wear between moving parts, such as pistons, valves, and pumps. By creating a thin film between the surfaces, the lubricant prevents direct metal-to-metal contact, minimizing wear and extending the lifespan of the components. Second, it cools the hydraulic system by carrying away heat generated by friction and compression. Overheating can damage seals, reduce the oil's viscosity, and accelerate its degradation. Third, it protects against corrosion by forming a barrier between the metal surfaces and corrosive elements, such as water, seawater, and air. Corrosion can weaken the components and lead to failures. Fourth, it removes contaminants, such as dirt, wear debris, and water, from the system. These contaminants can cause abrasive wear and damage to the components. Fifth, it transmits power by acting as the working fluid in the hydraulic system. The lubricant must have the appropriate viscosity and compressibility to efficiently transfer power. Selecting the wrong lubricant can lead to increased wear, overheating, corrosion, contamination, and reduced power transmission efficiency, all of which can significantly shorten the lifespan of the hydraulic components. Factors to consider when selecting a lubricant include viscosity, viscosity index, pour point, flash point, oxidation stability, demulsibility (ability to separate from water), and compatibility with seals and other materials in the system.