Spray angle and droplet size analysis for gas turbine fogging

The performance of fogging impaction pin nozzles is highly dependent on the spray droplet sizes and spray angles. The risk of compressor blade erosion and corrosion increase if large water particles are present. In the compressor path, effective water droplet evaporation is determined by droplet siz...

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Main Author: Tan, Beng Chiat
Format: Thesis
Language:English
Published: 2021
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Online Access:http://eprints.utm.my/id/eprint/101940/1/TanBengChiatPSKM2021.pdf
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spelling my-utm-ep.1019402023-07-25T09:39:30Z Spray angle and droplet size analysis for gas turbine fogging 2021 Tan, Beng Chiat TJ Mechanical engineering and machinery The performance of fogging impaction pin nozzles is highly dependent on the spray droplet sizes and spray angles. The risk of compressor blade erosion and corrosion increase if large water particles are present. In the compressor path, effective water droplet evaporation is determined by droplet sizes, water droplets distribution, and concentration within the fogging system. Big droplets are hard to evaporate in time and will invade on Gas Turbine Air Inlet Guide Vane and compressor blades and eventually cause erosion and corrosion due to water hammering. The sizes of droplet and spray angles depend a lot on the impaction pin angles and nozzle orifice geometry but their relationships causing water hammering is still unknown. This study aimed to establish relationships of impaction pin angles and nozzle orifice diameters geometrical effect towards spray angles and droplets sizes for Alstom GT13E2 Gas Turbine inlet fogging. Both experimental data and numerical techniques were used in this research. Image Feature Consolidation Technique and shadowgraph methods were used in the experimental works to capture and analyse the flow output from the impaction pins. Two-dimensional and three-dimensional numerical techniques were employed by varying pressure and pin angles to determine their effects on the spray angles. A multiphase model was used in numerical modelling. The results showed that the small nozzle orifices and small impaction pin angles operated at high pressure produced smaller droplet sizes. A high-pressure flow seemed to produce a smaller spray angle. The spray angle was increased by almost 50% if the orifice size was reduced by 0.5mm. The spray angle was increased about 6% when the pin angle was reduced from 60° to 45° and 2% for pin angle reduction from 45° to 30 °. This research reveals that the optimized impaction pin angles for Alstom GT13E2 Gas Turbine are 30° to 57°. With that, the number of nozzles can be optimized by 7%. Three reference charts, namely Number of Nozzle Chart (NONC), Spray Angle Chart (SAC), and Number of Nozzle According Orifice Size Chart (NONAOSC), are established from this research. The charts can be used to estimate the number of nozzles that are needed for Alstom GT13E2 Gas Turbine model operation, which is according to pin angle and orifice size. 2021 Thesis http://eprints.utm.my/id/eprint/101940/ http://eprints.utm.my/id/eprint/101940/1/TanBengChiatPSKM2021.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:149312 phd doctoral Universiti Teknologi Malaysia, Faculty of Engineering - School of Mechanical Engineering Faculty of Engineering - School of Mechanical Engineering
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic TJ Mechanical engineering and machinery
spellingShingle TJ Mechanical engineering and machinery
Tan, Beng Chiat
Spray angle and droplet size analysis for gas turbine fogging
description The performance of fogging impaction pin nozzles is highly dependent on the spray droplet sizes and spray angles. The risk of compressor blade erosion and corrosion increase if large water particles are present. In the compressor path, effective water droplet evaporation is determined by droplet sizes, water droplets distribution, and concentration within the fogging system. Big droplets are hard to evaporate in time and will invade on Gas Turbine Air Inlet Guide Vane and compressor blades and eventually cause erosion and corrosion due to water hammering. The sizes of droplet and spray angles depend a lot on the impaction pin angles and nozzle orifice geometry but their relationships causing water hammering is still unknown. This study aimed to establish relationships of impaction pin angles and nozzle orifice diameters geometrical effect towards spray angles and droplets sizes for Alstom GT13E2 Gas Turbine inlet fogging. Both experimental data and numerical techniques were used in this research. Image Feature Consolidation Technique and shadowgraph methods were used in the experimental works to capture and analyse the flow output from the impaction pins. Two-dimensional and three-dimensional numerical techniques were employed by varying pressure and pin angles to determine their effects on the spray angles. A multiphase model was used in numerical modelling. The results showed that the small nozzle orifices and small impaction pin angles operated at high pressure produced smaller droplet sizes. A high-pressure flow seemed to produce a smaller spray angle. The spray angle was increased by almost 50% if the orifice size was reduced by 0.5mm. The spray angle was increased about 6% when the pin angle was reduced from 60° to 45° and 2% for pin angle reduction from 45° to 30 °. This research reveals that the optimized impaction pin angles for Alstom GT13E2 Gas Turbine are 30° to 57°. With that, the number of nozzles can be optimized by 7%. Three reference charts, namely Number of Nozzle Chart (NONC), Spray Angle Chart (SAC), and Number of Nozzle According Orifice Size Chart (NONAOSC), are established from this research. The charts can be used to estimate the number of nozzles that are needed for Alstom GT13E2 Gas Turbine model operation, which is according to pin angle and orifice size.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Tan, Beng Chiat
author_facet Tan, Beng Chiat
author_sort Tan, Beng Chiat
title Spray angle and droplet size analysis for gas turbine fogging
title_short Spray angle and droplet size analysis for gas turbine fogging
title_full Spray angle and droplet size analysis for gas turbine fogging
title_fullStr Spray angle and droplet size analysis for gas turbine fogging
title_full_unstemmed Spray angle and droplet size analysis for gas turbine fogging
title_sort spray angle and droplet size analysis for gas turbine fogging
granting_institution Universiti Teknologi Malaysia, Faculty of Engineering - School of Mechanical Engineering
granting_department Faculty of Engineering - School of Mechanical Engineering
publishDate 2021
url http://eprints.utm.my/id/eprint/101940/1/TanBengChiatPSKM2021.pdf
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