EFFECT OF WATER TEMPERATURE AT INLET TO THE STEAM GENERATING CHANNEL ON STABILITY OF THE TWO-PHASE FLOW


  • M.M. Kovetskaya Institute of Engineering Thermophysics of the National Academy of Sciences of Ukraine
Keywords: natural convection, two-phase flow stability

Abstract

The paper considers the influence of the coolant temperature on stability of the flow in the closed loop of thermal-hydraulic test bench in the natural circulation mode. The loop includes a lifting section with a heated and unheated zone, condenser and lowering section where the single-phase coolant flows. The regime is considered, when the heat flow on the wall of the heated channel remains constant and the temperature of the coolant inlet increases.

The effect of underheating at entrance to heated channel on the stability of the natural circulation of the coolant is considered. A one dimensional unsteady mathematical model of a two-phase coolant flow is presented. Boundaries of natural circulation instability region are determined depending on the coolant underheating at the entrance to the heated channel. Fluctuations in coolant flow rate are characterized by regular shape and an antiphase change in the flow rate at the outlet.

The ambiguous effect of underheating of the coolant at the entrance to the steam generating channel on the boundary of the stability of a two-phase flow is shown: at low values of underheating, its increasing destabilizes flow; at large underheating its increasing stabilizes the flow.

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Published
2019-01-31
How to Cite
Kovetskaya, M. (2019). EFFECT OF WATER TEMPERATURE AT INLET TO THE STEAM GENERATING CHANNEL ON STABILITY OF THE TWO-PHASE FLOW. Thermophysics and Thermal Power Engineering, 41(2), 27-34. https://doi.org/https://doi.org/10.31472/ttpe.2.2019.4
Section
Heat and Mass Transfer Processes and Equipment, Theory and Practice of Drying