Experimental heat transfer in supercritical water flowing inside channels (survey)

Pioro, Igor; Duffey, Romney B.

doi:10.1016/j.nucengdes.2005.05.034

Cited by 293 publications

(73 citation statements)

References 15 publications

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“…[5][6][7] Generally, it is noted that enhanced heat transfer can be achieved on a heating surface when the bulk fluid temperature is not only slightly below the pseudocritical temperature, but also, the temperature of the heating surface is slightly higher than the pseudocritical temperature. Besides, it is well known that the heat transfer deterioration might be induced due to the occurrence of pseudofilm boiling as the temperature of the heating surface becomes higher than the pseudocritical temperature.…”

Section: Previous Study On Heat Transfer Characteristics Around Pseudmentioning

confidence: 99%

Experimental Study on Heat Transfer Characteristics of Vertical 5×5 Heated Rod Bundles around Critical Pressure with R-134a

Watanabe

Chun

Aritomi

et al. 2011

J. Nucl. Sci. Technol.

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With the aim of researching the heat transfer characteristics around the critical pressure in rod bundle geometry, the behaviors of the heating surface temperatures at the vertical 5Â5 heated rod bundles with R-134a were experimentally investigated under both pressurizing and depressurizing processes, where the pressure constantly decreases from supercritical to subcritical and constantly increases from subcritical to supercritical under constant inlet thermal conditions. As the pressure approaches the critical pressure, a DNB type or a dryout type of CHF was induced, and then the post-CHF was kept until the vicinity of the critical pressure. Under the supercritical pressure, the post-CHF disappeared due to the extinction of boiling phenomena, but the heat transfer deterioration was induced in a certain pressure range. In the depressurizing process, the heating surface temperatures followed the trajectory of temperature behaviors as in the pressurizing process except for the quenching point. The quenching point from the post-CHF moved to the lower pressure side than the pressure as for the CHF in the pressurizing process. This phenomenon was considered as the hysteresis phenomenon frequently observed in pool boiling curve characteristics.

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Section: Previous Study On Heat Transfer Characteristics Around Pseudmentioning

confidence: 99%

Experimental Study on Heat Transfer Characteristics of Vertical 5×5 Heated Rod Bundles around Critical Pressure with R-134a

Watanabe

Chun

Aritomi

et al. 2011

J. Nucl. Sci. Technol.

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“…There are many previous investigations of the heat transfer phenomena with water as the coolant, as cited by Pioro [38], however, the correlations that were derived from these studies vary wildly (Figure 1-6 The new wall function model that was developed requires input from experimental data under a set of appropriate conditions to determine key constants. To obtain these constants, details of the momentum and thermal boundary layer thickness and turbulence levels in the momentum and thermal boundary layer are needed i.e., the fluctuating velocities and density as a function of radial position (u', v', and ρ').…”

Section: Figure 1-2mentioning

confidence: 99%

Heat Transfer Phenomena in Supercritical Water Nuclear Reactors

Anderson¹,

Corradini²,

Bonazza³

et al. 2007

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A supercritical water heat transfer facility has been built at the University of Wisconsin to study heat transfer in a circular and square annular flow channel. A series of integral heat transfer measurements has been carried out over a wide data. Low mass velocity data has provided some insight into the difficulty in applying these Nusselt correlations to a region of deteriorated heat transfer.Geometrical differences in heat transfer were seen when deterioration was present. Jackson's buoyancy criterion predicted the onset of deterioration while modifications were applied to Seo's Froude number based criterion. Chapter 1 -Introduction IntroductionIn an effort to improve the efficiency of current Light Water Reactors (LWR's), the Generation IV initiative has included the conceptual design of Supercritical WaterReactor (SCWR) as one of the next steps in future nuclear reactors [8]. A SCWR will achieve efficiencies of about 44%, compared with current LWR efficiencies of about 34%, by operating its coolant at higher temperature (500 o C) and pressure (25 MPa) than current LWR's ( Figure 1-1 and Table 1). These operating conditions are above the pseudo-critical temperature of water (defined as the temperature, for a given pressure, at which the specific heat exhibits a maximum) and thus the coolant of SCW reactors will undergo large thermo-physical property changes (Figure 1-2 Two key experiments performed by Yamagata et al. [53] and Shitsman[48] investigated the thermophysical property variation effects on SCW heat transfer in a heated up-flow tube geometry at high and low mass velocities.Yamagata's data was performed at a relatively high mass velocity of (1260 kg/m 2 s) with varying heat flux. Yamagata's data shows that as the bulk enthalpy is increased through the pseudo-critical temperature an enhancement in heat transfer occurs (Figure 1-3). This enhanced heat transfer is diminished by increasing heat flux and suggests that at some critical heat flux, the enhancement will be completely inhibited. Shitsman's data (low mass velocity, (430 kg/m 2 s)) indicates that as the bulk coolant enthalpy is increased through the pseudocritical temperature, deterioration in heat transfer can occur (Figure 1-4). At a low heat flux there is indication of a localized enhancement in heat transfer. As the heat flux is increased, the heat transfer progresses from an enhanced condition to a deteriorated condition. In fact at the highest heat flux case, the heat transfer is so poor that it resulted in a localized temperature spike from 400 to 600 o C.However, it should be noted that in difference to two-phase critical heat flux phenomena, the heat transfer recovers after either an enhancement or deterioration. (Figure 1-5a). Enhanced heat transfer occurs at a low heat flux with bulk temperatures near the pseudo-critical temperature. At these conditions, the energy input is not large enough to overcome the large values of specific heat and thus a low gradient in wall to bulk temperature is achieved (Figure 1-5b).The impa...

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“…But most studies have been focused on pure fluids such as water [7], carbon dioxide [8] and methane [9]. The main conclusion obtained with the previous studies is that deterioration or enhancement of heat transfer occurs when the wall temperature is higher than the critical temperature or pseudo-critical temperature [5][6][7][8][9]. So far, very few studies about heat transfer of supercritical kerosene have been reported, of which the majority are experimental studies.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on flow and convective heat transfer of aviation kerosene at supercritical conditions

Dang

Zhong

Chang

2012

Sci. China Technol. Sci.

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In this paper, characteristics of flow and convective heat transfer of China RP-3 kerosene in straight circular pipe were numerically studied. Navier-Stokes equations were solved using RNG k- turbulence model with low Reynolds number correction. The thermophysical and transport properties of the China RP-3 kerosene were calculated with a 10-species surrogate and the extended corresponding state method (ECS) combined with Benedict-Webb-Rubin equation. The independence of grids was first studied and the numerical results were then compared with experimental data for validation. Under flow conditions given in the paper, the results show that deterioration of convective heat transfer occurs when the wall temperature is slightly higher than the pseudo-critical temperature of kerosene for cases with wall heat flux of 1.2 and 0.8 MW/m 2 . The degree of the heat transfer deterioration is weakened as the heat flux decreases. The deterioration, however, does not happen when the heat flux on the pipe wall is reduced to 0.5 MW/m 2 . Based on the analysis of the near-wall turbulent properties, it is found that the heat transfer deterioration and then the enhancement are attributed partly to the change in the turbulent kinetic energy in the vicinity of pipe wall. The conventional heat transfer relations such as Sieder-Tate and Gnielinski formulas can be used for the estimation of kerosene heat convection under subcritical conditions, but they are not capable of predicting the phenomenon of heat transfer deterioration. The modified Bae-Kim formula can describe the heat transfer deterioration. In addition, the frictional drag would increase dramatically when the fuel transforms to the supercritical state. aviation kerosene, supercritical, convective heat transfer, numerical study Citation:Dang G X, Zhong F Q, Chen L H, et al. Numerical investigation on flow and convective heat transfer of aviation kerosene at supercritical conditions.

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Experimental heat transfer in supercritical water flowing inside channels (survey)

Cited by 293 publications

References 15 publications

Experimental Study on Heat Transfer Characteristics of Vertical 5×5 Heated Rod Bundles around Critical Pressure with R-134a

Experimental Study on Heat Transfer Characteristics of Vertical 5×5 Heated Rod Bundles around Critical Pressure with R-134a

Heat Transfer Phenomena in Supercritical Water Nuclear Reactors

Numerical investigation on flow and convective heat transfer of aviation kerosene at supercritical conditions

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