Оптимальные параметры диффузоров трактов отборов паровых турбин

Abstract

На основе результатов экспериментального исследования на крупномасштабном статическом стенде определены оптимальные геометрические параметры диффузорных трактов отборов в диапазоне изменения относительного расхода в отбор от 15 % до 40 %. Рассмотрено влияние площади отводящего патрубка на уровень потерь. Приведены аппроксимационные зависимости, позволяющие определить потери как в бездиффузорных конструкциях, так и в трактах, отличающихся параметрами диффузора.

Using the data of the experimental investigation carried out on the large-scale aerodynamic test bench the optimal sizes of the radial diffusers of bleeding routes in the range of change of the relative flow rate of the sampled medium of 15 to 40 % have been determined. The working section of the test bench includes the circular stage simulator after which a miner portion of air goes to the bleeding route and the major portion of air goes to the circular nozzle array. The average diameter of the nozzle array is 440 mm, and the blade height is 50 mm. Consideration was given to the influence of the branch pipe area on the level of losses in the routes with different diffusers; this allows for the use of the experimental data for the calculation of the real structures of gas turbines. Empirical formulas that allow for the determination of losses both in the diffusionless structures and in the channels with different parameters of the radial diffuser have been derived. The influence of the flow twisting and the relative flow rate of the bleeding medium on the losses in the bleeding route have been studied.