Global lubricant demand is forecast to reach 40.5 million metric tons in 2012. According to a recent study, the market is estimated at $48.8 billion. Companies in this booming market are expanding their lubricant lines to include those for more industries such as wind. Wind equipment requires specialized lubricants.
For instance, they may require certain blends of base oil and additives to cover different lubrication requirements of individual bearings in wind-power stations. One trend has been toward reducing maintenance costs and simplifying lubrication routines in the nacelle. Also, as wind turbines are built higher and in more extreme conditions, the trends is toward using low-viscosity lubricants to address cold weather effects, produce more power, and decrease micropitting.
Also, engineers are using specialty synthetics instead of mineral oils, along with particle counters to control contamination.
To reduce maintenance costs and simplify lubrication in the nacelle, operators are using one lubricant for all bearings.
“Repairs on wind turbines can be costly, difficult, and dangerous,” says Jesse Dilk, wind industry manager at Klüber. “Therefore, it is vital to use high-quality components at every opportunity. Bearings, seals, and lubricants are essential design elements when analyzing mechanical systems. Optimizing these elements leads to a more efficient, reliable machine design.”
For example, Klüber’s high-performance grease has a blend of base oil and additives to cover different lubrication requirements of individual bearings. Another adhesive grease lubricates gears in pitch and yaw drives, while reducing the risk of migration inside the nacelle and onto the tower.
Also, the industry has moved toward using synthetics instead of mineral oils to minimize maintenance. “The lubricants tend to be well balanced, and have been widely tested in laboratory rigs and in the field,” Dilk says. “The preference for synthetics include high wear protection, higher efficiency from lower friction, and a wide operating temperature range. Specialty synthetic lubricants typically outperform mineral-based versions under the same conditions. Synthetics are further driven by a requirement for extended lubrication intervals.”
Exxon Mobil Corp. engineers also say synthetic gear oil protects against micropitting, scuffing wear, and corrosion. Synthetic oils function over a wide temperature range and resist deposit formation. Furthermore, many new lubricants and greases extend oil change intervals from a matter of months to years, which significantly reduces time and cost of maintenance.
Shell Lubricants also says it recognizes the significance of reduced reliability and demands of operating wind farms in remote locations (on and offshore) and in harsh climates. Their engineers have developed a variety of lubricants to withstand extremely low temperatures and protect against micropitting and bearing wear. Another trend is to monitor the oil conditions, especially in gearboxes. Shell, for example, offers an oil-analysis program that can help operators monitor the condition of their lubricant along with equipment that helps avoid unscheduled downtime.
Finally, particle counters, such as those from Parker Hannifin Corp., provide contamination control for lubricants. Such units independently monitor system contamination trends, and give early warnings. LEDs or digital displays indicate low, medium, and high contamination levels. Such advancements, keep oil clean and increase its lifespan.