The EHC system of the turbine in a power plant is what keeps the power plant operating. Without the turbine operating at peak performance, the power plant can be heading towards an unplanned forced outage. As important as the EHC system is to the turbine operation, phosphate ester fluids are to the operation of the EHC system. However, phosphate ester fluids are just as vital to the operation of the EHC system as it is to a turbine. Filtering and conditioning the phosphate ester fluids is a challenging yet important task that can help avoid failure of EHC system components such as servo valves and hydraulic components.
While working with the EPRI (Electric Power Research Institute) and OEMs to develop best practices for filtering and maintaining phosphate ester fluids, our engineers developed two systems to address the need to reduce varnish and maintain TAN (Total Acid Number) levels in phosphate ester fluid to extend the life of servo valves and other hydraulic components.
Prevent Varnishing with Purification Skid
Older systems typically have higher micron filters incorporated into the system with synthetic filter technology. Synthetic filters over time have proven not compatible with the EHC fluid, therefore stainless steel is recommended. We have developed a purification skid that uses ion exchange technology coupled with a water absorbing contamination element for polishing the EHC fyrquel unit to prevent varnishing. Incorporated into the purification skid is an f-pack stainless steel media 3 micron duplex filter that continuously filters contaminants out of the oil. An air cooler is also provided to keep phosphate ester temperatures within OEM temperature ranges. Maintaining temperature and water content in OEM acceptable ranges prevents varnish from being formed through hydrolysis.
Condition Phosphate Ester Oils with Air Dryer / Coalescing Technology
Air dryer and coalescing technology is also used for conditioning phosphate ester oils. This technology uses instrument air to keep the air in the reservoir dry and clean. A dry environment is necessary for phosphate ester oils because if water content is too high, varnish can develop through hydrolysis. Older technology used a desiccant breather but in power plants this technology was inefficient because reservoir fluid levels seldom change. Our air dryer design incorporates the latest design technologies and eliminates design flaws of competition.
