CAUSES OF EROSION-INDUCED DAMAGE TO ELEMENTS OF LOW-PRESSURE EVAPORATOR CIRCUITS OF THE HEAT-RECOVERY BOILERS OF COMBINED-CYCLE POWER PLANTS

摘要

An analysis of the causes of erosion-induced wear of the metal in pipe bends of evaporator heating pipe surfaces is performed based on experience gained from the operation of the heat-recovery boilers of combined-cycle (steam-gas) power plants. Damage to the evaporator tubes of a low-pressure boiling circuit is caused by the destruction of the protective oxide film due to intensive turbulization of the near-wall layer of water (which is at saturation temperature) travelling through the bend, inducing cavitation due to the formation of steam bubbles and their condensation. The protective oxide film formed in the hydrate water chemistry regime possesses the greatest stability.