A technically advanced lubricant will keep turbines operating on top form

Credit: ExxonMobil

Gas plant managers can boost production and profitability by selecting the right lubricant for their turbines, writes Jarmo Vihersalo

To satisfy ever-increasing demands for electricity, gas turbine power plant managers are keen to improve the output and reliability of their operations. Through selecting the right lubricant, operators can maximize production and profitability and reduce unscheduled downtime, which helps increase worker safety. Varnish formation is one factor that can have a highly detrimental effect on gas turbine operations.

During operation, varnish deposits can build up and stick to various interior surfaces and block openings and filters, which can reduce power output and reliability. To combat this, operators should look for a turbine oil with higher level base stocks and advanced antioxidants which can provide protection against oxidation when properly formulated.

While treating the symptoms of varnish through mitigation technologies may extend service life, the important factors for reliable operation are starting with a clean system and using a turbine oil designed to prevent varnish from forming. A well-balanced oil formulation that utilizes high-performance base stocks and advanced technology additives is the first line of defence against the formation of sludge and varnish.

To select a well-balanced gas turbine lubricant, maintenance personnel should consider the following performance areas:

Deposit Control – advanced turbine oils are formulated to limit the generation of sludge and varnish, while keeping deposits in suspension;

Oxidation Stability – higher level turbine oil base stocks and advanced antioxidants can provide protection against oxidation;

Advanced lubricants can help mitigate injury risks during maintenance procedures

Credit: ExxonMobil

Air Release and Foam Control – oils formulated to have rapid air release and minimal foam formation will provide superior protection against the formation of varnish;

Filterability (the ability of an oil to pass through a filter with minimal pressure drop) – oils with poor filterability will pollute filters faster that those with good filterability. This often translates into more frequent filter changes;

Anti-Rust and Corrosion protection – oils formulated to minimize rust and corrosion that contribute to oxidation and the formation of contaminant-based varnish will reduce the likelihood of varnish formation;

Wear protection – wear material from high pressure hydraulics, the gears of the accessory gearbox, and generator reduction gear or turning gear can indirectly be a source of varnish formation, since the wear metals will act as an oxidation catalyst.

Safety is another fundamental concern and the number one priority for power generation companies. Maintenance procedures carried out during both scheduled and unscheduled downtime have the potential to put operators at risk through direct contact with equipment. Advanced lubricants can help mitigate potential injury risks and increase overall productivity for both owners and operators of gas and steam turbines. By extending equipment and component life, for example, advanced lubricants help reduce unscheduled downtime and contribute to reducing employees’ exposure to hazardous maintenance procedures.

The balanced formulations used in the development of Mobil industrial lubricants are designed specifically with these benefits in mind. For example, Mobil DTE™ 732 M can help minimize safety risks and improve turbine reliability thanks to its high performance features, such as:

Long oil and filter life: the lubricant’s excellent chemical and oxidation stability help reduce maintenance downtime and costs by contributing to system cleanliness and deposit reduction, which can enable long oil and filter life;

Long equipment life: powerful protection against rust and corrosion of critical oil system components helps to minimize maintenance and can promote long component life;

– Turbine reliability: Mobil DTE 732 M demonstrates high resistance to foaming and rapid air release while minimizing sludge formation potential, which can help control maintenance downtime by promoting reliable turbine operation.

The power industry is facing increasing demands and operators are continuously looking for solutions that help improve safety and increase productivity. To do this, operators need to select a lubricant that can perform in a range of demanding conditions – including high temperature, heavy load, and water contamination – and delivers outstanding product performance. A technically advanced lubricant that can help owners meet these goals will help keep plants operating on top form.

Jarmo Vihersalo is Europe, Africa and Middle East Industrial marketing advisor for energy at ExxonMobil.