Experimental study of condensing steam flow in nozzles and linear blade cascade

Abstract

Experimental investigations of non-equilibrium spontaneous condensation in transonic steam flow were carried out in nozzles and linear blade cascade. For the tests the geometry of the half arc nozzles were used. The linear cascade consists of the stator blades of the last stage low pressure steam turbine. The applied experimental test section is a part of small scale steam power station located at the Silesian University of Technology. The steam parameters at the test section inlet correspond to the real conditions in low pressure part of steam turbine. The applied linear cascade consists of four stator blades of the last LP stage, it means that the flow through three full blade-to-blade channels were investigated. The information about the flow-filed were acquired by means of static pressure measurements on the pressure and suction side of the one bladeto-blade channel and with the use of Schlieren technique. The static pressure measurements on the blades surfaces were synchronized with the measured total parameters at the inlet and also with the Schlieren pictures, with the frequency of 100Hz. The tests were performed for the wide range of the outlet Mach number (Ma=0.8-1.4). The capabilities of used measurement techniques were estimated for gaining insight into condensation process in steam flow. The experimental results were compared with numerical calculations carried out by means of an in-house CFD code.

CFD-based shape optimization of steam turbine blade cascade in transonic two phase flows

“…According to the condensation model adopted here (Eqs. [12][13][14][15][16][17][18], the phase change is represented by two mass sources:…”

“…Additionally, the predicted droplet radius distribution along the nozzle is in a reasonable agreement with the experimental data. [34] As the second case for the validation of our CFD code, the steam turbine blade cascade of Dykas et al [15] is considered. The cascade is designed to operate under the condition of P 0 =89 kPa and T 0 =373.15 K at its flow inlet.…”

“…The numerical grid is consists of 43480 quadrilateral computational cells with its size is chosen through a detailed grid size study. Being done with the verification of our CFD code, it should be mentioned that in this work the Moore's "Nozzle A" [34] and the turbine blade cascade of Dykas et al [15] are selected as the base profiles for the shape optimization process. Realizable k- k- SST Experimental data [15] Pressure Side…”

“…The main motivation behind the study was the examination of the adverse effect of liquid droplet deposition (onto turbine blade) on the performance of the turbine. Dykas et al [15] carried out detailed experiments on transonic wet steam flows through two different geometries, a Laval nozzle and a stationary linear blade cascade. As a major finding, the formation of coarse water droplets prompted by shock waves was reported near the outlet of the nozzle and at the trailing edge of blades.…”

CFD modeling of condensation process of water vapor in supersonic flows

“…Theoretical and experimental studies have been conducted for the condensation process in supersonic flows, focusing on the nucleation theory, droplet size, latent heat [10][11][12]. Numerical simulations have been performed to predict the condensing flow with the development of the computational fluid dynamics (CFD) for several decades.…”