Abstract
Microchannels offer unique advantages on heat transfer performance. In this paper, microchannels are applied to the compound parabolic concentrator (CPC) system. A multi-physical field coupling model based on Finite Element Method is proposed to investigate the homogenization effect of the microchannel heat absorber on the CPC non-uniform concentration. The energy conversion process from optics to heat is simulated using TracePro software, and the heat transfer processes in the microchannel are computed by Fluent using user defined functions (UDF). It is found that the microchannels behave well on weakening the influence of the nonuniformity solar heat flux on the performance of the CPC. The temperature nonuniformity of the outlet section is less than 10−3 in the direction of fluid flow caused by the microchannel, although the maximum surface heat flux inhomogeneity of the microchannel reaches 2.3. The peak value of the heat flux on the surface of the absorber changes from double peak to single peak, and moves to the edge, resulting in more uneven heat flux distribution with the increase of the incident angle within the acceptance semi-angle of the CPC. The result of TracePro clearly shows that when the concentration ratio is less than 5, the heat flux nonuniformity on the surface of the absorber decreases with the increase in concentration ratio. It was interestingly found that the temperature distribution of the heat transfer fluid has weak sensitivity to the changes of truncation ratio. This work provides a way to design a CPC solar collector.
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Abbreviations
- a :
-
the aperture width of CPC/m
- C :
-
concentration ratio
- C t :
-
truncation ratio
- f :
-
parabolic focal length/m
- H :
-
the vertical distance from the aperture to the starting point of profile CPC/m the vertical distance from the aperture to
- H t :
-
the starting point of profile after CPC truncation/m
- i :
-
data serial number
- K :
-
uniformity
- M :
-
the arithmetic mean of data
- n :
-
the number of data
- p :
-
fluid pressure/Pa
- s :
-
the width of microchannel absorber/m
- T :
-
the temperature of working fluid/K
- u :
-
the velocity/m·s−1
- α :
-
thermal diffusivity of fluid of working/m2·s−1
- θ :
-
the incident angle/(°)
- θ max :
-
the acceptance semi-angle of CPC/(°)
- ρ :
-
density of working fluid/kg·m−3
- σ :
-
the standard deviation of the data
References
Tian M., Su Y., Zheng H., et al., A review on the recent research progress in the compound parabolic concentrator (CPC) for solar energy applications. Renewable and Sustainable Energy Reviews, 2018, 82: 1272–1296.
Zhang G., Wei J., Wang Z., et al., Investigation into effects of non-uniform irradiance and photovoltaic temperature on performances of photovoltaic/thermal systems coupled with truncated compound parabolic concentrators. Applied Energy, 2019, 250: 245–256.
Meng H., The experimental and computational research on the intensity distribution of CPC absorber plate. Acta Energiae Solaris Sinica, 1996, 17(2): 151–156.
Ding H., Research on transfer characteristics of internal CPC vacuum solar thermal collector. Northeast Electric Power University, Jilin, China, 2017. (in Chinese)
He Y., Wang K., Du B., et al., Non-uniform characteristics of solar flux distribution in the concentrating solar power systems and its corresponding solutions: A review. Science China Press, 2016, 61(30): 3208–3237.
Li G., Pei G., Su Y., et al., Design and investigation of a novel lens-walled compound parabolic concentrator with air gap. Applied Energy, 2014, 125: 21–27.
Zhang H., Chen H., Han Y., et al., Experimental and simulation studies on a novel compound parabolic concentrator. Renewable Energy, 2018, 113: 784–794.
Geng C., Xue Q., Zhang W., et al., Thermal stress analysis for absorber tube of parabolic trough solar collector under non-uniform heat flux. Journal of Engineering for Thermal Energy and Power, 2019, 34(3): 121–127.
Peng H., Li M., Liang X., Thermal-hydraulic and thermodynamic performance of parabolic trough solar receiver partially filled with gradient metal foam. Energy, 2020, 211: 119046.
Nabeel A., Imran A., Andrea C., et al., Assessment and evaluation of the thermal performance of various working fluids in parabolic trough collectors of solar thermal power plants under non-uniform heat flux distribution conditions. Energies, 2020, 13(15): 1–27.
Ying Z., He B., Su L., et al., Convective heat transfer of molten salt-based nanofluid in a receiver tube with non-uniform heat flux. Applied Thermal Engineering, 2020, 181: 1–12.
Akbarimoosavi S.M., Yaghoubi M., 3D thermal-structural analysis of an absorber tube of a parabolic trough collector and the effect of tube deflection on optical efficiency. Energy Procedia, 2014, 49: 2433–2443.
Aldali Y., Muneer T., Henderson D., Solar absorber tube analysis: thermal simulation using CFD. International Journal of Low-Carbon Technologies, 2011, 8(1): 14–19.
Robles A., Duong V., Martin A.J., et al., Aluminum minichannel solar water heater performance under year-round weather conditions. Solar Energy, 2014, 110: 356–364.
Zhou J., Zhao X., Yuan Y., et al., Operational performance of a novel heat pump coupled with mini-channel PV/T and thermal panel in low solar radiation. Energy and Built Environment, 2020, 1(1): 50–59.
Sharma N., Diaz G., Performance model of a novel evacuated-tube solar collector based on minichannels. Solar Energy, 2011, 85(5): 881–890.
Widyolar B., Jiang L., Brinkley J., et al., Experimental performance of an ultra-low-cost solar photovoltaic-thermal (PVT) collector using aluminum minichannels and nonimaging optics. Applied Energy, 2020, 268: 1–11.
Wang Z., Huang Z., Chen F., et al., Experimental investigation of the novel BIPV/T system employing micro-channel flat-plate heat pipes. Building Services Engineering Research and Technology, 2018, 39(5): 540–556.
Li G., Zhang G., He W., et al., Performance analysis on a solar concentrating thermoelectric generator using the micro-channel heat pipe array. Energy Conversion and Management, 2016, 112: 191–198.
Zhou J., Cao X., Zhang N., et al., Micro-channel heat sink: a review. Journal of Thermal Science, 2020, 29(6): 1431–1462.
Rabl A., Optical and thermal properties of compound parabolic concentrators. Solar Energy, 1976, 18(6): 497–511.
Smyth M., Zacharopoulos A., Eames P.C., An experimental procedure to determine solar energy flux distributions on the absorber of line-axis compound parabolic concentrators. Renewable Energy, 1999, 16(1–4): 761–764.
Wang Y., Liu Q., Lei J., et al., A three-dimensional simulation of a parabolic trough solar collector system using molten salt as heat transfer fluid. Applied Thermal Engineering, 2014, 70(1): 462–476.
Hawwash A., Rahman A.K.A., Nada S., et al., Numerical investigation and experimental verification of performance enhancement of flat plate solar collector using nanofluids. Applied Thermal Engineering, 2018, 130: 363–374.
Li S., On the coefficient of standard deviation. China Statistics, 1988, (5): 32–33.
Geedipalli S.S.R., Rakesh V., Datta A.K., Modeling the heating uniformity contributed by a rotating turntable in microwave ovens. Journal of Food Engineering, 2007, 82(3): 359–368.
Zhang M., Ai Y., Zhang S., et al., Effect of different layout schemes on temperature uniformity of cold storage. Jiangsu Agricultural Sciences, 2020, 48(2): 210–221.
Acknowledgements
This present study was supported by the National Natural Science Foundation of China (51506004), Beijing Scholars Program (2015No.022) and Fundamental Research Funds for Beijing University of Civil Engineering and Architecture (X20065).
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Wang, X., Wu, H., Ma, Y. et al. Homogenization Function of Microchannel on Heat Absorber with Compound Parabolic Concentrator. J. Therm. Sci. 31, 2022–2031 (2022). https://doi.org/10.1007/s11630-022-1609-6
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DOI: https://doi.org/10.1007/s11630-022-1609-6