EXPERIMENTAL INVESTIGATION OF CRITICAL HEAT FLUX IN ANNULUS AT LOW PRESSURE AND LOW FLOW PARAMETERS

Authors

  • Daniel Vlček Czech Technical University in Prague, Czech Republic
  • Ladislav Suk Brno University of Technology, Czech Republic
  • Kamil Števanka Brno University of Technology, Czech Republic
  • Taron Petrosyan Brno University of Technology, Czech Republic

DOI:

https://doi.org/10.14311/APP.2020.28.0050

Keywords:

correlations, critical heat flux, flow boiling, heat transfer

Abstract

Steady state flow boiling experiments were conducted on a technically smooth Inconel 625 tube with outer diameter 9.1 mm at inlet pressures 131, 220 and 323 kPa, inlet temperatures 62, 78 and 94 °C and approximately 400, 600 and 1000 kg/(m2.s) mass flow. Water of these parameters was entering into the vertically aligned annulus, where the uniformly heated tube was placed until the critical heat flux (CHF) appeared. The experimental data were compared to estimations of CHF by local PGT tube correlation and Groeneveld’s look-up tables for tubes. The results imply that in the region of low pressure and low mass flux, the differences between calculations and experiments are substantial (more than 50 % of CHF). The calculations further imply that look-up tables and tube correlations should be corrected to the annulus geometry. Here, the Doerffer’s approach was chosen and led to a substantial enhancement of CHF estimation. Yet, a new correlation for the region of low pressure and flow is needed.

Author Biographies

Daniel Vlček, Czech Technical University in Prague, Czech Republic

Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, Department of
Nuclear Reactors, Brehová 78/7, Prague, Czech republic

Ladislav Suk, Brno University of Technology, Czech Republic

Brno University of Technology, Faculty of Mechanical Engineering, Technická 2896/2, 61669 Brno, Czech
Republic

Kamil Števanka, Brno University of Technology, Czech Republic

Brno University of Technology, Faculty of Electrical Engineering and Communication, Technická 10, 616 00
Brno, Czech Republic

Taron Petrosyan, Brno University of Technology, Czech Republic

Brno University of Technology, Faculty of Electrical Engineering and Communication, Technická 10, 616 00
Brno, Czech Republic

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Published

2020-12-01