Remotely monitoring turbomachinery

Robert Salemme, GE, Corporate Research & Development; and Leonardo Rosi, GEPS, Nuovo Pignone

Faced with ever-increasing economic pressures, equipment service and maintenance philosophies are changing from a reactive to a proactive mode. Proactive maintenance, also referred to as condition-based maintenance, is an approach based on a forecast of the future condition of the machine through trend analysis of service data and the equipment operating plan. The key is having an accurate and detailed record of machine performance over time as a basis for forecasting. Remote Monitoring and Diagnostics (RM&D) provide the database and interpretation tools.

Software screen shot showing parameters monitored for a turbine-driven generator.

The system. The RM&D system collects and transmits machine operating data to a central facility staffed by experts in machine analysis, diagnostics and maintenance planning, and backed by specialized software for analysis, extrapolation and interpretation of data. Data are archived to provide a continuous historical record of detailed performance of the machine over time. Because of data volume and complex interactions between parameters, sophisticated algorithms and software are needed for correct assessment and trending of thermodynamic and mechanical performance. The RM&D system performs two important functions:

   Real-time fault detection. If a deviation in machine parameters is detected, the central RM&D facility is automatically notified, and a diagnostic process is initiated to evaluate the root cause of the deviation and necessary action(s). Experts at the center request a download of data and employ a variety of analytical tools for verification of the deviation, diagnosis of the problem and formulation of a recommendation. Plant operations personnel are then contacted, and a course of action is initiated. This real-time fault-detection capability makes it possible to spot a problem in the development stages and react quickly, allowing time for an orderly intervention coordinated with other process equipment, thus avoiding potential secondary damage.

   Trend analysis employs statistical methods to extrapolate machine performance based on its operating history and the equipment-operating plan. This forecast allows time for scheduling maintenance resources and for coordinating with the plant operations schedule. In this way, machines can be efficiently maintained at peak operating conditions maximizing fuel efficiency and machine life.

Main benefits. RM&D benefits fall into three categories: 1) increased plant output; 2) lower turbomachinery operating and maintenance costs; and 3) predictable / planned maintenance scheduling. These benefits have direct impacts on economics and stability of plant operations. RM&D is expected to become an integral part of turbomachinery plant operations.