Monitoring & Fault Diagnostics Solution
A fast and easy access to reliable information about actual faults and their causes is a prerequisite for finding an economic solution to any problem in the engine. Through the multitude of functions and diagrams available for fault recognition, Gas Turbines Solution Center machinery analysis provides both standard and innovative tools to support utilizing vibration-oriented maintenance strategies for turbo- machinery.
Using the vibration module the operator is able to deeply study the vibration-based fault patterns.
By help of this module the operator can detect and handle the following events and phenomena: unbalance, misalignment, cracks in rotor, rubbing in seals, rubbing between rotor and stator, blade failure, looseness, housing and foundation resonance, different kinds of gearbox-problems & problems related to combustion.
Almost all diagnostic diagrams are interactive and permit simultaneous display of data for several measurement points, thus permitting correlations between causes and effects to be identified.
The software supports different plots regarding mode of acquisition (real-time, historic and transient), such as time signal, FFT spectrum, waterfall, cascade, orbit, shaft center line, bode and polar and offers a very friendly HMI.
Startup and run-down procedures can also be monitored by comparing every measured vibration value with the corresponding value from a statistically determined reference procedure.
It takes alarming to a new level by providing quick and easy views of machine status. In case amplitude of vibration reaches the pre-specified limits, the alarm goes off in the control room the data is stored to decide on further appropriate actions.
Fault-diagnosis sub-module consists of a distinct and separate page giving the operator the possibility to use a rule-based method to diagnose the most probable faults based on the symptoms observed while monitoring the system.
Solution Center has been specifically developed for the diagnostic monitoring of gas turbines. It perfectly fulfills the following tasks: monitoring, archiving & analysis.
The package contains a data acquisition unit which includes an acquisition rack, and a PC to be placed in the control room. Data read by the sensors enters the rack and is conditioned before it is used as the input to the software.
The archiving procedure is done by storing the data into a SQL server so that recalling would be possible for further actions. Data can be saved in different formats such as Time signal, RMS, Kurtosis and Skewness.
The package also supports remote monitoring.
Analyses, available in the vibration module are:
- Frequency domain: FFT spectrum, Order spectrum, Full spectrum.
- Run up & shut down: Bode & Polar plot, Cascade.
- Steady state condition: Waterfall, Order tracking
- Orbit and shaft center line plots are also included.
An alarm has been considered in case any sudden change in the amplitude occurs or if the amplitude reaches the pre-defined limits. One of the best features is that the operator can determine a time period to save the data before and after an alarm happens.
The diagnosis sub-module uses 2 methods:
- Rule based
- DT (decision tree)
Based on the observed symptoms the operator answers some questions and software comes up with results on the most probable faults. Print and save options are available in all the plots and the module is able to create a report of recent activities.
The Performance module has a main page with icons representing critical performance parameters of the gas turbine. Upon choosing any of the parameters the regarding trend would be available. This feature works for following parameters:
All input & output temperatures, humidity, pressure, turbine & compressor’s speed, Pressure ratio in the compressor, amount of air & fuel flow, polytrophic efficiency and finally normalized mass flow, IGV’s angle & compressor pressure ratio with respect to normalized GG’s speed.
- GPA and GPD (Gas Path Analysis & Gas Path Diagnosis) are also included in the module. The former shows variation of health parameters like flow capacity and efficiency in different sections of gas turbine with respect to reference values. Based on these results, the latter performs the diagnosis process and comes up with a percentage for the most probable causes like fouling, erosion etc.
- Burner diagnosis is another sub-module which calculates the probability of having a faulty burner, in percent.
- Life estimation is a specific feature of performance module which gets operation time, load value and number of starts as inputs and calculates design life, consumed life, remaining life and remaining life fraction as the outputs.
- Filter health monitoring draws a trend for variation of pressure loss between the two sides of the filter and any error is displayed.
- Eco-Analysis is a sub-module to evaluate cost for faults like fouling and erosion in order to offer the best time to perform compressor washing.
- Alarm history produces a report on history of the system (events