Effect of flow channel dimensions on the performance of a box-frame photovoltaic/thermal collector

Abstract

The hybrid photovoltaic/thermal (PV/T) collector technology is a new trend in solar energy application. For the thermal absorber, a box-frame water-channel design is able to enhance better heat transfer between the solar cells and the liquid coolant, thereby improving the combined electrical and thermal performance of the collector. This article reports the findings of the effect of water-flow channel dimensions on the energy performance of a box-frame PV/T collector design. A mathematical model of this PV/T collector system was first developed. Dynamic simulation results the authors obtained show that both the number and the height of the water-flow channels can significantly affect the collector performance. With a reduction in the channel height and an increase in the number of channels per unit width, better convective heat transfer between the working fluid and the channel wall can be achieved. This improves both the thermal and the electrical efficiencies of the collector. However, this also leads to an increase in the friction loss at the water circuit and, therefore, more pumping power is required. The optimal designs are discussed.

Keywords

hybrid photovoltaic/thermal collector water flow in channel photovoltaic and thermal performance

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References

Chow

T. T.

Performance analysis of photovoltaic-thermal collector by explicit dynamic model. Sol. Energy, 2003, 75, 143–152.

Zondag

H. A.

de Vires

D. W.

Helden

W. G. J.

van Zolingen

R. J. C.

van Steenhoven

A. A.

The yield of different combined PV-thermal collector designs. Sol. Energy, 2003, 74, 253–269.

Matrawy

K. K.

Theoretical analysis for an air heater with a box-type absorber. Sol. Energy, 1998, 63 (3), 191–198.

Kabeel

A. E.

Mecarik

Shape optimization for absorber plates of solar air collectors. Renew. Energy, 1998, 13, 121–123.

Gee

Webb

R. L.

Forced convection heat transfer in helically rib-roughened tubes. Int. J. Heat Mass Transf., 1980, 23, 1127–1136.

Han

J. C.

Heat transfer and friction in channels with two opposite rib-roughened walls. J. Heat Transf., 1984, 106, 774.

Webb

R. L.

Eckert

E. R. G.

Goidstein

R. J.

Heat transfer and friction in tubes with repeated rip roughness. Int. J. Heat Mass Transf., 1971, 14, 601–617.

Baumann

Rehme

Friction correlation for rectangular roughness. Int. J. Heat Mass Transf., 1975, 18, 1189–1197.

Ligrani

P. M.

Moffat

R. J.

Structure of transitionally rough and fully rough turbulent boundary layers. J. Fluid Mech., 1986, 162, 69–98.

10.

Kakac

Yener

Convective heat transfer, 1980 (Hemisphere Publishing, New York).

11.

Brinkworth

B. J.

Estimation of flow and heat transfer for the design of PV cooling ducts. Sol. Energy, 2000, 69 (5), 413–420.

12.

Chow

T. T.

Hybrid photovoltaic-thermosyphon water heating system for residential application. Sol. Energy, 2006, 80 (3), 298–306.

13.

Watmuff

J. H.

Charters

W. W. S.

Proctor

Solar and wind induced external coefficients for solar collectors. Comples, 1977, 2, 56.

14.

Holman

J. P.

Heat transfer, metric editions, 1989 (McGraw Hill, Singapore).

15.

Heaton

H. S.

Reynolds

N. C.

Kays

W. M.

Heat transfer in annular passages, simultaneous development of velocity and temperature fields in laminar flow. Int. J. Heat Mass Transf., 1964, 7, 763.

16.

Bergene

Lovvik

O. M.

Model calculations on a flat-plate solar heat collector with integrated solar cells. Sol. Energy, 1995, 55, 453–462.

17.

Huang

B. J.

Lin

T. H.

Hung

W. C.

Sun

F. S.

Performance evaluation of solar photovoltaic/thermal systems. Sol. Energy, 2001, 70 (5), 443–448.