ASME POM 102:2014 pdf free download

ASME POM 102:2014 pdf free download.Operating Walkdowns of Power Plants.
B-i PERFORMANCE CONSIDERATIONS
Gas turbines are air-breathing engines. The expected performance of a gas turbine is based on the quantity of air that can he ingested by the compressor and sent to the turbine section for power generation. A higher mass flow of air leads to greater power generation and often higher efficiencies. When tracking the operating performance of a gas turbine, it is best to look at corrected performance, such that an apples-to-apples comparison can be made over time.
Gas turbines are subjected to high operating temperatures, especially in the combustion section and the early stages of the turbine. These high temperatures cause normal degradation in the turbine section. The degradation may be recoverable with normal maintenance practices, but there are also some forms of degradation that are nonrecoverahic. Additional performance degradation can be attributed to compressor fouling, which is often recoverable. Understanding how fast the unit is degrading relative to expectations will lead to better predictive maintenance practices and potentially longer parts life (and therefore lower total maintenance costs).
B-2 EQUIPMENT WALKDOWN
The following are some items to observe while the unit is operating to verify that you are getting the most out of your gas turbine:
(a) Calculate the current heat rate for the gas turbine in its current operating state.
(b)Calculate the compressor efficiency of the gas tur-bine in its current operating state.
(c)Note the gross output and IGv angle for the cur-rent operating point. If the gas turbine is on its baseload curve, calculate the corrected output and heat rateof the gas turbine for comparison with design values.(d)Note the current setting for the inlet bleed heatvalve (if present). Once the gas turbine reaches a certainload level, the inlet bleed heat valve should be fullyclosed. When this valve is open, warm compressed airis circulated back to the gas turbine inlet, which lowersthe density of air entering the compressor and reducesthe amount of air available to the turbine for powergeneration.
(e)Note the differential pressure across the inlet fil-ters. High inlet-filter pressure loss will result in lostcapacity and higher heat rates.
(f)Observe and note the condition of filters.
(g) Walk around the gas turbine and record anyobservable fluid leaks (air, water, oil, etc.).
(h) Walk around the gas turbine and record anyobservable material problems, such as corrosion, loosefittings, or severe vibrations.
(i) An additional consideration is that following awater wash, and prior to starting the unit, water-washdrains should be verified to be clear, with no standingwater. Standing water may impact instrumentationreadings, leading to poor performance and / or unit trips.