Flow boiling and critical heat flux in horizontal channel with one-sided and double-sided heating

Consolidated methodology to predicting flow boiling critical heat flux for inclined channels in Earth gravity and for microgravity

“…For U = 1.5 m/s, a significant increase in inertia yielded virtually identical wavy vapor layer interfacial behavior over the entire range of orientations. In a more recent study, Kharangate et al [35] observed the same wavy vapor layer behavior for both singlesided and double-sided heating in horizontal flow in Earth gravity for U P 1 m/s. In another study, Konishi et al [39] observed the same wavy vapor layer behavior for both single-sided and double-sided heating in microgravity for 0.1 < U < 1.9 m/s.…”

“…Similar trends were measured by Konishi et al [34] for twophase inlet conditions, x e,in P 0. Kharangate et al [35,36] studied horizontal flow of FC-72 in a rectangular channel with both bottom wall heating and top wall heating over a wide range of channel inlet conditions, ranging from highly subcooled to positive inlet quality. Both wall heating configurations had Earth gravity perpendicular to the heated wall, with gravity aiding vapor removal from the heated wall for bottom wall heating, while causing vapor accumulation along the heated wall for top wall heating.…”

“…A stable interface, which will be discussed later in this study, corresponds to low CHF values beyond the validity range of the Interfacial Lift-off Model. In two separate studies, Kharangate et al [35,36] showed that bottom-wall heating below U = 0.5 m/s yields conditions resembling pool boiling that are dominated by gravity, and for which the wavy vapor layer is not observed. The velocity ranges associated with a stable interface (U 6 1.0 m/s for top-wall heating and U 6 0.5 m/s for double-sided heating) and pool boiling behavior (U 6 0.5 m/s for bottom-wall heating) impose lower limits for validity of the Interfacial Lift-off Model, as indicated in Fig.…”

“…(a) Depiction of horizontal flow boiling near CHF for a rectangular channel with top-wall heating, bottom-wall heating, and double-sided heating (adapted from[35]). (b) Hydrodynamic instability of wavy vapor layers along heated walls of double-sided heated channel at CHF-for inclined channel in Earth gravity and for microgravity (adapted from[40]).…”

Effects of Cooling Fluid Flow Rate on the Critical Heat Flux and Flow Stability in the Plate Fuel Type 2 MW TRIGA Reactor

“…Neutronically, the core structure will change the power distribution, while the cooling process will also be changed. These conditions will affect the safety limit of the core, especially its thermohydraulic aspects such as boiling limit, critical heat flux (CHF) limit, and cooling flow stability [1][2][3][4]. The Bandung TRIGA 2000 reactor used a natural convection cooling system type, but with the conversion into a square core, the cooling will be performed by means of forced convection, and the cooling fluid will flow in a very narrow channel of about 2.3 mm between the fuel plates.…”