Critical areas where a CM solution could be usefully employed include: mechanical systems for vibration and current monitoring; pneumatic systems for temperature, pressure, condensation, air flow and filter monitoring; hydraulic systems for oil pressure, temperature, level, flow, accumulator and filter monitoring; and electrical systems for power quality and temperature monitoring.
Gurney says several options exist for analyzing data. "In many cases, data can be fed directly into a computerized maintenance management software system, and the data never needs to be directly presented to maintenance personnel," he says. "Companies will also offer to take on this function for customers—where they analyze the data directly and work with the maintenance staff or with third-party mechanical, pneumatic, hydraulic or electrical specialists."
The other critical element of a CM solution is measuring the results. "Overall equipment effectiveness determines gains recognized by a CM solution," he explains. "Having this data prior to the CM implementation will deliver quantifiable data on the improvements when viewed before and after the project."
Powerful Condition Monitoring
The installation at Centro Energia Teverola's 150-MW combined cycle cogeneration power plant in Teverola, Italy, near Naples, illustrates two key aspects of modern condition monitoring (CM) and asset management systems.
First, it may not matter what kind of new or legacy control system is installed at your plant because modern CM software packages can work with almost any system. Second, you don't have to develop specific knowledge about CM because outside services exist that will analyze the data and recommend best courses of action.
Centro Energia had a legacy Bailey Infi-90 control system with 5000 I/O, and it wanted to monitor clogging problems with inlet filters on its gas turbines as well as other operations. The data Centro Energia needed to analyze was already being collected by the control system, so all the company had to do was install Emerson Process Management's AMS Performance Monitor software and contract for Emerson's remote analysis services.
It's necessary to monitor the gradual deterioration in filter performance and calculate the cost of the resulting reduction in turbine performance. By comparing this with the cost of the maintenance required, the most appropriate point to replace the blocked filter can be determined.
But Centro Energia doesn't make the determination: Filter and other data from Teverola is transmitted to Emerson's performance monitoring center of expertise in Teesside, in northeastern England, where experienced engineers analyze the data and produce reports showing performance. These reports can be accessed via any standard web browser, and are based on thermodynamic models developed for each machine.
In addition to the online information, Emerson also provides advice about the operational efficiency of machinery. Existing or potential problems are highlighted, as well as new opportunities to improve overall efficiency.
Vincenzo Piscitelli, general manager, Centro Energia Teverola, says, "We can assess the effectiveness and economic return of our maintenance activities, which allows us to determine what maintenance work is required to improve equipment performance."
This improved planning has also enabled Centro Energia Teverola to reduce average repair times from seven hours to two hours.