“Inlet Air Pretreatment for Gas Turbines” was the subject of the Hot Topic Hour on Thursday March 14, 2013
In the Hot Topic session held yesterday, we learned that gas turbine performance and maintenance are greatly affected by the cleanliness and physical properties of the incoming air. Moisture can be a problem. Temperature correlates directly with gas turbine output. On a hot day just when maximum generation is required the output will be reduced.
Luke Buntz, Mechanical Engineer, Kiewit Power Engineers Co.l discussed the ARCTIC (Absorption Refrigeration Cycle Turbine Inlet Conditioning) System. ARCTIC is a breakthrough in inlet conditioning technology from Kiewit Power Engineers that uses waste heat to drive an ammonia absorption system. By use of a patented process, ARCTIC allows power plant owners the flexibility to maximize the output or efficiency of a combustion turbine by manipulating the turbine inlet temperature with a fraction of the auxiliary load of a comparable mechanical chiller. A successful installation has now become the basis of full commercial offerings.
Jerrod Walters, Gas Turbine Business Development Manager and Bryan Xu, Gas Turbine Product Manager at TDC Filter Manufacturing, Inc., (A Midwesco Filter Resources Company) explained that a Merv 16 rated filter can substantially reduce turbine offline water wash frequently. Also in one case, the more efficient filter resulted in 2 MW greater power output. High efficiency filter media is effective in coastal areas. It reduces corrosion from airborne salts.
Tom Kelmartin, Global Product Specialist for Gore® Turbine Filters at W.L. Gore & Associates, Inc. discussed “A new HEPA solution for gas turbine inlet air filtration.” Filtration of turbine inlet combustion air is employed to reduce compressor fouling and the commensurate power loss. However, it has been largely ineffective at capturing submicron particles, necessitating periodic turbine shutdowns for off-line washing. High efficiency HEPA solutions have been employed for a number of years with some success, but these systems frequently require multiple filtration stages resulting in higher initial pressure drops.
A new HEPA solution has been introduced which is a direct retrofit for existing filter houses, with similar pressure drops and lifetimes of conventional lower efficiency filters. This membrane filter has a HEPA rating of H12/E12. In one case, the Gore E12 reduced pollutants to just 0.09 lbs/yr vs. 12.3 lbs/yr for an E10 filter and 29 lbs/yr for an F9. The cost of the more efficient filter is 3 to 4 times that of less efficient filters but the improvements in performance and maintenance can provide pay back in just weeks.
Mcleod Stephens of Nederman and Tony Poovey presented data on complete air inlet treatment for combustion turbines. The company supplies complete intake systems to Alstom, GE, Siemens, Mitsubishi and others. Air filtration is supplemented by cooling, anti-icing, moisture removal and humidity control. Both multi-stage static intake air systems and Up Draft and Cross Flow self cleaning systems are supplied.
The company takes a practical approach. Heating can be supplied for units in cold wet climates. If a lack of heating capability causes an outage only rarely, it may not be warranted. High efficiency filters may not be necessary if the unit is operated only a few hundred hours per year in peaking service. Nederman has the capability to upgrade existing units for better performance. An initial analysis can determine what additional features should be incorporated.
Bios, Abstracts and Photos can be seen at: BIOS, ABSTRACTS, PHOTOS - 3-14-13.htm
The individual presentations are as follows: