Numerical study on combined free-forced convection heat loss of solar cavity receiver under wind environments

Wind Effect on Combined Convection and Surface Radiation Heat Losses of a Fully Open Cylindrical Cavity With Insulation

“…But for α>30°, the effect of resistance holds dominant position, and then Nu c is reduced. In addition, Nu c caused by the sideon wind (α=0°) is larger than that by the head-on wind (α=90°) for all V studied, which coincides 16 with that of Ma [6]. Fig.…”

“…Results also illustrated that when wind direction was parallel to the receiver aperture, convection heat loss reached the maximum value. Xiao et al [16] showed that for some wind cases the convection heat loss may not decrease monotonically with increasing tilt angle as that of no-wind cases. As wind speed increased, the convection heat loss of receiver at different tilt angles became more and more indistinguishable.…”

“…After sodium vapor transferring heat to the U-tubes of the engine, it becomes liquid again. Considering Literatures so far considering wind effect mainly focus on the thermal condition of constant wall temperature on all walls of cavity [8][9][10][11]16], while the work about constant wall temperature only on the bottom wall is rarely reported. In view of the above-mentioned facts, the main purpose of this paper is to analyze wind effect on convection and surface radiation heat losses of a fully open cylindrical cavity with constant bottom wall temperature.…”

Thermal Model of a Dish Stirling Cavity-Receiver

“…Wu et al [16] reviewed different possible situations in convection losses; concluding that an inclination close to 90° makes the stagnant zone fill the cavity interior space; therefore, a stable temperature stratification is generated, which reduces the convective losses to negligible values. The distribution of this stagnation zone distribution was researched by Prakash et al [17], and the wind influence in that zone was studied by Xiao et al [18], who illustrated the wind velocity, wind inclination, and cavity inclination influence in the final convection losses. Wu et al [19] studied natural convection heat loss variation, concluding that it is more sensitive to tilt angle and aperture size, except when tilt angle is 90° (when the stagnant zone fills the interior space).…”

Experimental Study on The Effect of Wind on Heat Losses from a Fully Open Cylindrical Cavity with only Bottom Wall Heated

“…Fang et The results show that changing the wind incidence angle or velocity can obviously affect the air velocity inside the receiver and the heat loss reaches maximum for side-on wind. Xiao et al (2012) gave a numerical study on combined free-forced convection heat loss of a cylindrical cavity under wind environments. The research reveals that the combined convection heat loss decreases observably with increasing inclination for a small wind speed but does not vary much with a high-speed wind.…”