Boiling, pool critical heat flux

For region 1 (pool-boiling-type critical heat flux) the critical heat flux for staggered bundles is given by... 

Ivey, H. J., Acceleration and the critical heat flux in pool boiling heat transfer, Proc. Inst. Mech. Engrs. (London) (1962). 

Adams, J. M., 1962. A Study of the Critical Heat Flux in an Accelerating Pool Boiling System, Report NSF G-19697, University of Washington, Seattle, WA. (2)... 

Beasant, W. R., and H. W. Jones, 1963, The Critical Heat Flux in Pool Boiling under Combined Effects of High Acceleration and Pressure, UK Rep. AEEW-R 275, Winfrith, England. (2)... 

Carne, M., and D. H. Charlesworth, 1966, Thermal Conduction Effects on the Critical Heat Flux in Pool Boiling, Chem. Eng. Prog. Symp. Ser. 62(64) 24-34. (5)... 

Cole, R., 1960, A Photographic Study of Pool Boiling in the Region of the Critical Heat Flux, AIChE J. 6 533. (2)... 

Subbotin, V. I., D. M. Ovechkin, D. N. Sorokin, and A. P. Kudryavtsev, 1968, Critical Heat Flux during Pool Boiling of Cesium, transl. from Teploenergetika 6 58. (2)... 

Tachibana, F., M. Akiyama, and H. Kawamura, 1968, Heat Transfer and Critical Heat Flux in Transient Boiling, 1. An Experimental Study in Saturated Pool Boiling, J. Nuclear Sci. Technol. of Japan 5(3) 117. (5)... 

Bar-Cohen, A., Watwe, A., and Arik, M., 2003, Pool Boiling Critical Heat Flux in Dielectric Liquids, Keynote Lecture, 5 International Conference on Boiling Heat Transfer, Montego Bay, Jamaiea, May 2003... 

The critical heat flux in pool boiling can be predicted reasonably closely by an equation developed by Zuber et al. [45] and Lienhard and Dhir [46], as reported by Hewitt et al. [30]. 

The results given in Fig. 9.20 show that for very small values of Bo (Bo < 0.01), the surface temperature also increases monotonically with the heat flux. This supports the theory of a heat removal mechanism that does not change, unlike that observed in the pool boiling in plain media. For the system shown in Fig. 9.20 and for d = 1.1 mm, the transition from the surface-wetted condition to the formation of a vapor film occurs at the critical heat flux... 

M. Carne, Some Effects of Test Section Geometry, in Saturated Pool Boiling, on the Critical Heat Flux for Some Organic Liquids and Liquid Mixtures, in AIChE Preprint 6 for 7th Nat. Heat Transfer Conf, AIChE, New York, August 1964. 

Pool Boiling Heat Transfer Before the Critical Heat Flux Limit... 

The Critical Heat Flux Limit in Pool Boiling... 

Effect of Pressure. The critical heat flux in pool boiling increases and then decreases with increasing pressure (tending to zero at the critical pressure) as illustrated in Fig. 15.60 (see also Fig. 15.34). 

Effect of Dissolved Gas. The presence of dissolved gas can lead to a considerable reduction in critical heat flux in pool boiling, as illustrated by the results of Jakob and Fritz [151] shown in Fig. 15.62. The effect of dissolved gases diminishes with decreasing subcooling (increasing fluid temperature), the effect being minimal near saturation conditions. 

Mechanisms of CHF in Fool Boiling. The mechanism of the critical heat flux phenomenon in pool boiling has been the subject of widespread interest and controversy. Recent reviews relating to mechanisms are presented by Katto [157], Dhir [87], and Bergles [158]. The postulated mechanisms can be approximately classified into four types as follows ... 

Correlations for CHF in Pool Boiling. Most correlations for critical heat flux in pool boiling have been of the form indicated in Eq. 15.128. Although this equation was introduced in the context of the hydrodynamic instability model of Zuber [159,160], the form of the equation was derived some years earlier by Kutateladze [166], Thus, the use of the equation is not necessarily associated with any physical model. In the following text, equations will be given for the most usual practical cases of horizontal flat plates and horizontal cylinders relationships for other shapes are discussed by Lienhard and Dhir [155,161],... 

It is for saturated pool boiling only if the liquid in the pool is subcooled, the critical heat flux is higher. 

FIGURE 15.47 Variation of pool-boiling critical heat flux with composition and pressure for ethanol/ benzene mixtures (from Afgan [170], with permission of Taylor Francis, Washington, DC. All rights reserved). 

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