Non-Hydrodynamic Aspects of Pool Boiling Burnout

Abstract

More than 400 pieces of test sections-flat plates made of various metals and alloys-were placed in saturated water under atmospheric pressure and heated to physical destruction by passing electric current directly through them.Several non-hydrodynamic parameters have marked effect upon the critical heat flux, which indicates that purely hydrodynamic theories are not directly applicable to general prediction of the critical heat flux.The critical heat flux data was found to be well correlated with tbe heat capacity per unit surface area of the test section: the critical heat flux is reduced with decrease of this parameter, while with increasing parameter it approaches a certain asymptotic value.The fluctuation of surface temperature due to alternate contact with vapor and liquid was calculated hy the proposed model, and the trend of dryout duration was estimated from the critical heat flux data.

Heat Transfer and Critical Heat Flux in Transient Boiling, (I)

“…6 it is seen that the heat capacity of the test section does not affect the critical heat flux in transient boiling s:> markedly as in steady state boiling. Under the present experimental conditions a test section of 0.05 mm thick is seen to be already ample to avoid the effect of small heat capacity, while in saturated pool boiling under steady power condition, a thickness of more than 0.8 mm is known to have been needed for a stainless steel plate to be free of the effect of heat capacity upon the critical heat flux< 9 l. In the same paper< 9 l, it was analyzed that, with a surface of small heat capacity, the critical heat flux in steady boiling depends upon sudden local temperature rise and the resulting Leidenfrost phenomena. In transient boiling, on the other hand, the critical condition occurs as already stated when certain parts of the wetted area are replaced by dryout areas.…”

Critical heat flux on a vertical surface in saturated pool boiling at high pressures

“…Further, according to the previous research (e.g. Houchin and Lienhard (1966), Tachibana et al (1967), and Golobic and Bergles (1997)), the CHF is greatly affected by thermal properties of heating surface, such as thickness, thermal conductivity and specific heat. Arik and Bar-Cohen (2003) presented that the CHF decreases with the decrease in the parameter S ( ) when S is smaller than 5 to 10.…”

Critical Heat Flux on a Vertical Surface in Saturated Pool Boiling at High Pressures

“…Further, according to the previous research (e.g. Houchin and Lienhard (1966), Tachibana et al (1967), and Golobic and Bergles (1997)), the CHF is greatly affected by thermal properties of heating surface, such as thickness, thermal conductivity and specific heat. Arik and Bar-Cohen (2003) presented that the CHF decreases with the decrease in the parameter S (= � ℎ ℎ ℎ ) when S is smaller than 5 to 10.…”