Study on the suppression effect of variable hydrogen parameters on the temperature rise of the turbo-generator rotor under deep peak regulation

Abstract

In recent years, the extensive participation of turbine generator in deep peak regulation has caused significant damage to the rotor windings, which is rooted in the frequent and significant changes in the electrical load of the rotor, accompanied by thermal expansion and contraction, causing harm to the rotor insulation and stress fatigue of the metal conductor. Hydrogen, as the cooling medium for the rotor windings of turbine generators, has a direct impact on the windings temperature through its parameters. Starting from suppressing the harm of deep peak regulation on the rotor windings, the inhibitory effect of hydrogen parameter changes on the temperature of the gap-pickup diagonal-flow rotor is studied. A calculation model for the rotor temperature field of the turbo-generator with gap-pickup diagonal-flow ventilation is established. The finite volume method is used to iteratively calculate the control equations in the fluid-thermal-solid coupling heat transfer problem, and the temperature field distribution of various components of the rotor under different excitation loads is obtained. On this basis, the effects of individual adjustment of hydrogen temperature and pressure, as well as the combined adjustment, on the temperature of the rotor windings are studied. Finally, a variable hydrogen parameter adjustment strategy is proposed for the operation of turbo-generators under deep peak regulation conditions. To a certain extent, the winding temperature fluctuation can be suppressed, which provides a potential solution for the thermal stable operation of the rotor.