Use of Cascade and Small Turbine Tests to Determine Erosion of Utility Turbines

Abstract

Experiments using cascades and small turbines have been conducted or are being considered to simulate large utility turbine operation with future coal-fired power plants. The purpose of these experiments is to evaluate utility turbine tolerances to particulates and to determine gas cleanup requirements for successful turbine performance. Since these tests do not fully reproduce the flow and erosion conditions in large utility turbines, this paper explores the interpretation of data from simulation experiments to assess erosion in large utility turbines. Effects of physical scale, rotation speed, and pressure differences between test cascades and small test turbines and large utility turbines are considered.

Deposition, Erosion and Corrosion Protection for Coal-Fired Gas Turbines

“…Slurry mean coal particle diameters from 9 to 52 microns all produced POC mean particle diameters ranging from 5.4 to 6.6 microns (12). Evidence from these and other combustion tests suggests that coalwater mixture POC particle size distributions may not be greatly affected by the fuel particle size distribution for small coal particle sizes but rather are mostly determined by the atomization droplet size distributions.…”

“…Decreasing the stator vane dimensions to one-fourth of original values increases the capture fraction to greater than 0.7. These results indicate scale effect uncertainties in using small size cascade and turbine tests to represent inertial impaction induced deposition and erosion in larger turbines (12).…”

“…Even though the combustor design caused the larger particles to be centrifuged to the wall and be captured there, a significant fraction of ash particles larger than 5 microns (for which inertial impaction is important) was carried over from the combustor. Over 50 percent larger than 5 microns and 20 percent larger than 10 microns was measured in combustion products of a coal-water mixture with a mean coal particle diameter of nine microns (12).…”

Combustion Turbine Deposition Observations From Residual and Simulated Residual Oil Studies

“…Physical scale adjustments are necessary because tests and analyses have shown (17) that a larger fraction of approaching particles strike the cylinder with decreasing cylinder diameters. Pressure adjustments are necessary because particle arrival rates are proportional to the local particle concentration per unit volume of gas, which is proportional to gas pressure (18).…”

Experimental research on hot state selection of PFBC-CC gas turbine blade coatings

“…As gas turbine blades work in adverse circumstances, their corrosion/ erosion is an urgent problem. Study reports (Rollbubler, 1980;Wenglarz, 1982) of U.S.A. and Sweden, etc. point out that coating can increase the life of gas turbine blades.…”