Open AccessEFFECT OF WATER TEMPERATURE AT INLET TO THE STEAM GENERATING CHANNEL ON STABILITY OF THE TWO-PHASE FLOW
Author(s) -
М. M. Kovetskaya
Publication year - 2019
Publication title -
teplofìzika ta teploenergetika
Language(s) - English
Resource type - Journals
eISSN - 2663-7235
pISSN - 2663-7243
DOI - 10.31472/ttpe.2.2019.4
Subject(s) - coolant , natural circulation , mechanics , thermodynamics , flow (mathematics) , volumetric flow rate , inlet , heat transfer , materials science , two phase flow , thermal hydraulics , condenser (optics) , subcooling , open channel flow , physics , mechanical engineering , engineering , light source , optics
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.