Critical Heat Flux with Subcooled Flowing Water in Tubes for Pressures from Atmosphere to Near-Critical Point

Abstract

During last 45 years, two groups of the experimental data on critical heat flux were obtained in bare tubes, covering the pressures from atmosphere to near-critical point. One group of the data were obtained in the inner diameter of 2.32, 5.16, 8.05, 10.0 and 16.0 mm, respectively, with the ranges of pressure of 0.1-1.92 MPa, velocity of 1.47-23.3 m/s, local subcooling of 3.7-108.7 °C and heat flux of up to 38.3 MW/m 2. Another group of the data were obtained in the inner diameter of 4.62, 7.98 and 10.89 mm, respectively, with the ranges of pressure of 1.7-20.6 MPa, mass flux of 454-4,055 kg/(m 2 •s) and inlet subcooling of 53-361 °C. The results showed complicated effects of the pressure, mass flux, subcooling and diameter on the critical heat flux. They were formulated by two empirical correlations. A mechanistic model on the limit of heat transfer capability from the bubbly layer to the subcooled core was also proposed for all the results.

Critical Heat Flux of Flowing Water in Tube for Pressure Up to Near Critical Point—Experiment and Prediction

“…In the previous study, an empirical correlation was proposed to formulate the subcooled experimental results of D ¼ 4.62, 7.98, and 10.89 mm with heated lengths of 0.5, 0.8, and 1.1 m, respectively [18]. The conditions are listed in Table 1.…”

“…In the author's previous study, the experiments of subcooled flowing water were performed in the uniform heating tubes of inner diameters from 2.32 to 16 mm for pressure of 0.1-2 MPa and from 4.62 to 10.89 mm for pressure of 2-20.6 MPa [18]. The empirical correlations and theoretical predicted method were proposed.…”