Analysis of internal helically finned tubes for parabolic trough design by CFD tools

Muñoz, Javier; Abánades, A.

doi:10.1016/j.apenergy.2011.04.026

Cited by 215 publications

(81 citation statements)

References 21 publications

(27 reference statements)

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“…11, that due to the non-uniform heat flux distribution, the heat transfer fluid will be hotter in the lower half of the absorber tube where concentrated heat flux is received than in the top half where only direct normal radiation is received. This trend was also shown by (Muñoz and Abánades, 2011). The temperature distribution in the receiver's glass cover follows the same trend as that in the receiver's absorber tube.…”

Section: Receiver Thermal Performancesupporting

confidence: 61%

“…In the third approach, a concentrated heat flux is applied on the lower half of the receiver tube and a direct normal irradiance value on the upper half of the absorber tube. This approach is similar to the one used by Muñoz and Abánades (2011). As shown In Table 3, using a uniform heat flux over predicts the performance of the receiver by about 13% while using a concentrated heat flux profile on the absorber tube's lower half under predicts the overall thermal efficiency about to 7% compared with a model that uses an actual non-uniform heat flux profile.…”

Section: Receiver Thermal Performancementioning

confidence: 51%

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Influence of optical errors on the thermal and thermodynamic performance of a solar parabolic trough receiver

et al. 2016

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HIGHLIGHTS• Effect of optical errors on performance of a parabolic trough receiver is presented.• Actual heat flux profiles were obtained using Monte Carlo ray tracing and presented.• Thermal and thermodynamic analysis of the receiver is determined numerically.• Effect of optical errors on heat flux and temperature distribution is investigated.• Influence of optical errors on receiver entropy generation rates is presented. ABSTRACTThis paper presents results of an investigation covering the influence of optical errors on the thermal and thermodynamic performance of a solar parabolic trough system. The optical performance was evaluated by using Monte Carlo ray tracing for slope errors and specularity For the range of parameters considered, the intercept factor reduces by up to 21% while the overall thermal efficiency reduces by up to 17% as optical errors increase. Receiver thermodynamic performance is shown to deteriorate as slope errors increase.

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Section: Receiver Thermal Performancesupporting

confidence: 61%

Section: Receiver Thermal Performancementioning

confidence: 51%

Influence of optical errors on the thermal and thermodynamic performance of a solar parabolic trough receiver

et al. 2016

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“…Most failures of parabolic trough receivers, especially the breakage of the glass cover have been attributed to the circumferential temperature gradients in the absorber tube [2,13]. Therefore, reducing these temperature gradients and temperature peaks can go a long way in increasing the life span of the receiver and avoiding the thermal loss due to vacuum loss and hydrogen permeation in receiver's annulus space.…”

Section: Introductionmentioning

confidence: 99%

“…At low flow rates, higher temperature gradients existing in the tube's circumference can cause bending of the tube and eventual breakage of the glass cover [12,13]. And the peak temperature in the absorber tube facilitate degradation of the heat transfer fluid especially as these temperatures increase above 673.15 K [14,15].…”

Section: Introductionmentioning

confidence: 99%

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Heat transfer and thermodynamic performance of a parabolic trough receiver with centrally placed perforated plate inserts

2014

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In this paper, a numerical investigation of thermal and thermodynamic performance of a receiver for a parabolic trough solar collector with perforated plate inserts is presented. The analysis was carried out for different perforated plate geometrical parameters including dimensionless plate orientation angle, the dimensionless plate spacing, and the dimensionless plate diameter. The Reynolds number varies in the range 1.02×10 4 ≤ Re ≤ 7.38 × 10 5 depending on the heat transfer fluid temperature. The fluid temperatures used are 400 K, 500 K, 600 K and 650 K. The porosity of the plate was fixed at 0.65. The study shows that, for a given value of insert orientation, insert spacing and insert size, there is a range of Reynolds numbers for which the thermal performance of the receiver improves with the use of perforated plate inserts. In this range, the modified thermal efficiency increases between 1.2 -8 %. The thermodynamic performance of the receiver due to inclusion of perforated plate inserts is shown to improve for flow rates lower than 0.01205 m 3 /s. Receiver temperature gradients are shown to reduce with the use of inserts. Correlations for Nusselt number and friction factor were also derived and presented.

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Real-time thermal states monitoring of absorber tube for parabolic trough solar collector with non-uniform solar flux

Wang

Zhang

et al. 2017

Int J Energy Res

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Summary With the world energy shortage problem becoming increasingly prominent, more and more attentions have been paid to the development of renewable energies. Among these sources, solar energy has received extensive attention with its excellent characteristics. The thermal state affects the safety of the solar heat collection system. In this paper, real‐time monitoring of the input heat flux on the inside wall and the temperature field simultaneously of an absorber tube for parabolic trough solar collector were studied. Based on the measured temperatures on the outside wall, the fuzzy adaptive Kalman filter coupled with weighted recursive least squares algorithm (WRLSA) was employed to monitor the heat states of the absorber tube inversely, in which WRLSA was used to acquire the heat flux while fuzzy adaptive Kalman filter was adopted to monitor the temperature field. The method showed strong robustness to resist the ill‐posedness. Accurate monitoring results also can be acquired when there are random disturbances of the heat transfer condition on the inner wall.

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Analysis of internal helically finned tubes for parabolic trough design by CFD tools

Cited by 215 publications

References 21 publications

Influence of optical errors on the thermal and thermodynamic performance of a solar parabolic trough receiver

Influence of optical errors on the thermal and thermodynamic performance of a solar parabolic trough receiver

Heat transfer and thermodynamic performance of a parabolic trough receiver with centrally placed perforated plate inserts

Real-time thermal states monitoring of absorber tube for parabolic trough solar collector with non-uniform solar flux

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