Analysis of the Hydraulic Regimes of Vertical Waste-Heat Boilers of Combined-Cycle Gas-Turbine Units

Abstract

An analysis of the hydraulic system of the natural circulation loop of the waste-heat boilers of combined-cycle gas turbine units is performed. It is demonstrated that the standard method of hydraulic calculation of steam boilers based on an evaluation of the reliability criteria of the hydraulic system and the thermal regime of the evaporator tubes is incorrect. The existence of loop-wide hydraulic persistence of flow in the low-pressure evaporator in natural circulation caused by elevated resistance of the steam-outlet tubes is demonstrated for the first time. Recommendations are given for increasing the reliability of the hydraulic system of the low-pressure evaporator loop and selecting an optimal combined water and chemical regime to prevent erosion wear of the metal of the inner surface of the evaporator tubes.