A two-dimensional mathematical model was developed for predicting the performance of an open-type water-cooled flat-plate solar collector, and solved numerically through an implicit finite difference method. The effects of various environmental and geometric conditions on energy absorption for the collector were investigated. The results predict that there is an optimum length and tilt angle for the absorbing plate for which the collector could obtain the highest solar energy absorptance. The latent heat flux of water evaporation can be 3 to 15 times larger than the sensible heat flux under normal operating conditions. The wind speed and the inlet water temperature have a large influence on the energy absorption of the collector. The effects of the solar incident flux, the atmospheric humidity and temperature, the absorbing plate tilt angle and length, and the water film thickness on the temperature rise of the water film and/or the absorptance of the collector are clarified. The open-type flat-plate collector is suitable to operate at lower inlet water temperatures and in regions where the local latitude is in the range of $20°N-40°N,$ and the weather is humid and hot with low winds. [S0199-6231(00)00202-1]

1.
Yan
,
W. M.
, and
Soong
,
C. Y.
,
1995
, “
Convective Heat and Mass Transfer along an Inclined Heated Plate With Film Evaporation
,”
Int. J. Heat Mass Transf.
,
38
, pp.
1261
1269
.
2.
Gandhidasan, P., 1986, “Heat and Mass Transfer in Solar Regenerators,” in Handbook of Heat and Mass Transfer, Cheremisinoff, N. P., ed., Gulf Publishing Company, Houston, 2, Chap. 37.
3.
Yang
,
R.
, and
Wang
,
P.-L.
,
1998
, “
Experimental Study for a Double-glazed Forced-flow Solar Collector/Regenerator
,”
ASME J. Sol. Energy Eng.
,
120
, pp.
253
259
.
4.
Schro¨ppel, J., Thiele, F., and Unterlo¨hner, O., 1981, “Mass, Heat, and Momentum Transfer in Laminar and Turbulent Pipe Flow with Vaporization of a Liquid Film,” in Numerical Methods in Thermal Problems, Lewis R. W., et al., eds., Pineridge Press, Swansea, 2, pp. 1215–1226.
5.
Karapantios
,
T. D.
,
Kostoglou
,
M.
, and
Karabelas
,
A. J.
,
1995
, “
Local Condensation Rates of Steam-air Mixtures in Direct Contact with a Falling Liquid Film
,”
Int. J. Heat Mass Transf.
,
38
, pp.
779
794
.
6.
Grossman, G., 1986, “Heat and Mass Transfer in Film Absorption,” in Handbook of Heat and Mass Transfer, Cheremisinoff, N. P., ed., Gulf Publishing Company, Houston, 2, Chap. 6.
7.
Fujita
,
Y.
, and
Tsutui
,
M.
,
1994
, “
Evaporation Heat Transfer of Falling Films on Horizontal Tube (1st report)
,”
Trans. Jpn. Soc. Mech. Eng., Ser. B
,
60
, pp.
3469
3474
(in Japanese).
8.
Yih, S. M., 1986, “Modeling Heat and Mass Transport in Falling Liquid Films,” in Handbook of Heat and Mass Transfer, Cheremisinoff, N. P., ed., Gulf Publishing Company, Houston, 2, Chap. 5.
9.
Song
,
B.
, and
Viskanta
,
R.
,
1990
, “
Deicing of Solids Using Radiant Heating
,”
J. Thermophys. Heat Transfer
,
4
, pp.
311
317
.
10.
Zhong, Z. Y., Yang, K. T., and Lloyd, J. R., 1985, “Variable-property Natural Convection in Tilted Enclosures With Thermal Radiation,” in Numerical Methods in Heat Transfer, Lewis R. W., and Morgan K., eds., Wiley, Chichester, 3, Chap. 9.
11.
Reid, R. C., Prausnitz, J. M., and Sherwood, T. K., 1977, The Properties of Gases and Liquids, 3rd edition, McGraw-Hill, New York.
12.
Brewster, M. Q., 1992, Thermal Radiative Transfer and Properties, Wiley, New York.
13.
Lunardini, V. J., 1981, Heat Transfer in Cold Climates, Van Nostrand Reinhold Company, New York.
14.
Patankar, S. V., 1980, Numerical Heat Transfer and Fluid Flow, Hemisphere/McGraw-Hill, New York.
15.
Cheremisinoff, P. N., P. E., and Regino, T. C., 1978, Principles & Applications of Solar Energy, Ann Arbor Science, Ann Arbor.