| 论文简介 |
Reducing solid particle erosion of blades is one of the most urgent problems for high-parameter steam turbine power
generation technology. Based on the erosion rate model and particle rebound model of blade materials obtained through
accelerated erosion test under high temperature, erosion characteristics of flaky particles in control stage of a typical
supercritical steam turbine were systemically studied using three-dimensional numerical simulation method. The erosion
mechanism of hard coatings on nozzle suction surface is first revealed, and erosion resistance of boride coating with large
oxide particles is validated through high-temperature erosion test. Results show that serious erosion damage of boride
coating on the latter half of nozzle suction surface is caused by the combined rebounded impingement of large particles
between 1000 mm and 2000 mm after their initial impingement on the nozzle pressure surface and the leading edge of
rotating blade. The average particle impingement velocity can reach up to 150–180 m/s, and the impingement angle is in
the range of 18–28. High-temperature erosion test results show that boride coating will soon broken and fall off under
the continuing impact of millimeter-sized particles, which confirms that hard coatings are difficult to resist the highintensity
impingement from these large particles. Therefore, separating particles before entering the nozzle chamber
with the employment of an inertial separator should be the optimal choice for improving the erosion resistance of
turbine. The results of this study enrich the types of blade erosion damage and provide a new idea for reducing erosion
damage of control stage blades. |
(创新港)
