Gas Turbine Performance Test

C

Thread Starter

Ch Amir Islam

Why do we have to perform "Performance Test" of Gas turbine? What else are proper, reliable & more efficient including the loop checking, calibration of 96AP, 96BD, 96CD, 96CS-1? Calibration of IGV, Angle measurement of IGV.? What else can make our test better? any clue regard any performance test curve?
 
Ch Amir Islam,

Your question is unclear.

What constitutes a "Performance Test" at your site?

Performance tests are usually done to ensure that a turbine is operating as efficiently as possible. Most turbines are provided with a heat-rate guarantee--not just a power output guarantee. Heat rate is the measure of how much power is produced for the amount of energy (thermal units) input to the prime mover. A lower heat rate is better (less thermal units) is better as it means the prime mover is more efficient. Power output is important--but efficiency is very important. New turbines are subjected to a rigorous performance test, using highly accurate, calibrated instruments installed just for testing.

Some operations contracts require operators to periodically demonstrate the turbine(s) are being operated as efficiently as possible, so a performance test is the way this is proven.

The instruments you list are part of the Performance Monitoring Package provided (sometimes optionally) by GE and/or packagers of its heavy duty gas turbine generators. Certainly, calibration of the instruments, and the cleanliness of the sensors and sensing lines, are critical to the quality of the information obtained from the instruments.

IGV LVDT calibration is <b>VERY</b> critical to power output <i><b>at Base Load</i></b>. For example, if the IGVs are actually, physically at 82.7 DGA but the LVDTs are calibrated such that the Speedtronic thinks the IGVs are at 84 DGA (maximum operating angle for a LOT of GE-design heavy duty gas turbines), then the air flow through the axial compressor--and hence the power output of the gas turbine--is limited.

Axial compressor and IGV cleanliness is also very important to power output--efficiency.

Performance guarantees (power output and heat rate) are made at a particular ambient temperature and relative humidity (usually 59 deg F, 60% relative humidity). Performance tests are almost NEVER performed at these ambient conditions, so correction curves provided by the manufacturer are employed to be able to correct the output, at say 94 deg F, back to 59 deg F so that the power output can be compared to the guarantee conditions.

Hope this helps! If you can tell us what a "performance test" constitutes at your site, we may be able to be more help, but at present your question is unclear.
 
Amir Islam,

Is your site one that is (or was) equipped with a "Datatronic" system that includes the performance monitoring program on the station computer? And if so, is that the performance test you are referring to?
As CSA noted,
>The instruments you list are part of the Performance Monitoring Package
> provided (sometimes optionally) by GE and/or packagers of its heavy duty gas
> turbine generators. Certainly, calibration of the instruments, and the
> cleanliness of the sensors and sensing lines, are critical to the quality of
> the information obtained from the instruments.

These instruments are mainly used to provide inputs for an airflow calculation. Airflow is one of the parameters used by that program to give performance data. Note, the program is useful for trending purposes to help determine when maintenance may be required. It does not provide results of sufficient accuracy for true performance tests.
 
Amir Islam,

otised is correct; the "Performance Monitoring Package" instruments are basically used to calculate airflow--which is one parameter used to analyze turbine performance.

The Packages were also provided with many turbines since the demise of the DataTronics system, and are even commonly provided with most F-class turbines and many other DLN combustor-equipped turbines.

The instruments and sensors used for the instruments are very "delicate" and require more maintenance than most sites provide. Most of the transmitters in the Performance Monitoring Package junction box have one of their pressure taps connected to sense ambient pressure. These taps can become plugged with spider's nest, bug nests, and dirt (depending on the environment and humidity). Also, the "Kiel probes" in the inlet duct can get dirty and plugged, and many times they are installed incorrectly or replaced incorrectly.
 
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