Innovative Real Time Particulate Monitor for Gas Turbine Inlet Filter Performance Monitoring

Etr Unidata has recently launch the Epsilon System, a totally innovative and groundbreaking instrument to measure particulates at sub ambient concentration levels on large gas turbine power station inlet ducts. The Epsilons is the only instrument in the world that is able to provide full duct coverage, on this type of application along with a spatial map of the distribution of the particulate within the duct itself. The instrument has been design to monitor the real time performance of large banks of inlet filters that protect the gas turbine compressor blades. These filter banks which can be up to six storeys high and contain several thousand filters, all of which have to be checked manually by the operator in the event of breakthrough or at the time of programmed maintenance

Once the gas turbine is online these inlet filters operate at varying degrees of efficiency, as they gradually deteriorate over time. The rate of deterioration is not always linear, and if a filter does break down, even partially, a stream of particles travels through the turbine at very high velocity, colliding with, eroding and shortening the life of the turbine blades. In extreme cases, catastrophic breakdown can occur. The expense of turbine blades, coupled with the opportunity cost of extended downtime if a failure occurs, means that operators build an insurance policy into their maintenance scheduling.

With realtime profiling of the entire crosssection of the filter, both the rate and the location of deterioration can be monitored continuously by the Epsilon system. Early warning of deterioration means downtime decisions can be made solely on the basis of process monitoring. If a decision to shut down is warranted, the specific location where repair or replacement is required will already be known, and the duration of downtime minimized.

Epsilon's ability to locate and focus on areas of deterioration creates the potential for huge savings in downtime. Overall filter bank efficiency can also be monitored over time. Epsilon employs advanced digital imaging processing combined with sophisticated signal processing to produce detailed crosssectional images of an entire duct/stack, from 18,000 separate images generated with Epsilon’s patented laser based scanning technology.

Cameron Stathers, The UK Sales Manager for ETiUnidata says: The instrument will bring significant benefits to gas turbine power station operators for the first time they will have real time information on how the individual inline filters are performing and will be able to make valued judgements on the build up of particulates on the compressor blades. We have already had interest from several major gas turbine power station operators in the system.