Influence of incident angle of hydrogen in the ventilation ducts on multi-physical fields of 1100 MW turbine-generator rotor

摘要

During the operation of a large-scale turbine-generator, hydrogen enters the ventilation ducts of the rotor with turbulent state, so that the inlet direction of hydrogen is difficult to solve under the influence of rotor rotation. The cooling effect of the rotor coil can be effected by the mainstream of hydrogen entering the ventilation ducts. With regard to this, it takes an 1100 MW turbine-generator with axial ventilation system, as a test generator, global fluid network equation is carried out to calculate the pressure field and velocity field of hydrogen in the rotor ventilation ducts. Based on the calculations, the fluid and heat transfer nonlinear equation for the rotor is established and calculated via finite volume method (FVM). First, the hydrogen flow law in the complex ventilation duct is investigated and the pressure losses of hydrogen in the corners from the rotor radial inlet area to the axial flow area and then into the radial outlet area are analyzed. Second, the rotor temperature fields are highlighted and investigated in the condition of incident angle alpha = 0 degrees, 15 degrees, 30 degrees, 45 degrees. The incident angle alpha = 0 degrees indicates vertical state between hydrogen flow direction and the rotor vent inlet. Simultaneously, the calculations of the average temperature in the rotor coils are compared with the experimental results to verify the accuracy of the calculation method. Additionally, the temperature distribution of rotor varying with the circumferential direction is investigated, which can provide theoretical basis for the larger scale turbine-generator. (C) 2019 Elsevier Ltd. All rights reserved.