ANALYSIS AND MODELING OF SOLAR EVAPORATOR-COLLECTOR
Solar energy is considered a sustainable resource that poses little to no harmful effects on the environment. The performance of a solar system depends to a great extent on the collector used for the conversion of solar radiant energy to thermal energy. A solar evaporator-collector (SEC) is basically an unglazed flat plate collector where refrigerants, such as R134a is used as the working fluid. As the operating temperature of the SEC is very low, it utilizes both solar irradiation and ambient energy leading to a much higher efficiency than the conventional collectors. This capability of SECs to utilize ambient energy also enables the system to operate at night. This type of collector can be locally made and is relatively much cheaper than the conventional collector.Â Â At the National University of Singapore, the evaporator-collector was integrated to a heat pump and the performance was investigated for several thermal applications: (i) water heating, (ii) drying and (iii) desalination. A 2-dimensional transient mathematical model of this system was developed and validated by experimental data. The present study provides a comprehensive study of performance.
KEYWORDS: heat pump; evaporator-collector.
 Sporn P, Ambrose ER. (1995) The heat pump and solar energy, in World symposium on applied solar energy. Phoenix, Arizona, USA.
 Franklin JL, Saaski EW, Yamgiwa A. (1977) A high efficiency, direct expansion solar plane, in Flat-Plate Solar Collector Conference. Orlando, Florida, USA.
 Chaturvedi SK, Chiang YF, Roberts As. (1982) Analysis of two-phase flow collectors with applications to heat pumps. ASME Transaction Journal of Solar Energy Engineering, 104(4):358-365.
 Chaturvedi SK, Mei VC. (1979) Thermal performance of SAHP system with combined collector/evaporator, in AIAA Terrestrial Energy Systems Conference. Orlando, Florida, USA.
 Soin RS, et al. (1979) Performance of flat plate solar collector with fluid undergoing phase change. Solar Energy, 23(1):69-73.
 Al-Tamimi AI, Clark JA. (1983) Thermal analysis of a solar collector containing a boiling fluid, in American Solar Energy Society Annual Meeting. Minneapolis, USA.
 Al-Tamimi AI, Clark JA. (1984) Thermal performance of a solar collector containing a boiling fluid (R-11). ASHRAE Transactions, 90:1B:681-693.
 Tong LS. (1965) Boiling heat transfer and two-phase flow. John Wiley and Sons Inc. New York.
 Chaturvedi SK, Roberts AS, Mei VC. (1979) Solar collector as heat pump evaporator, in 14th Intersociety Energy Conversion Engineering Conference. Boston, USA. American Chemical Society, Proceedings 1, 99-104.
 Hottel H, Whillier A. (1955) Evaluation of flat-plate solar collector performance, in Trans. Conf. Use of Solar Energy, 12 (3) (Thermal Processes) Part 2.
 Spears RP, Waldin VH. (1984) ASHRAE 109-A test standard for two-phase solar collectors. ASHRAE Transcations, 90:697-706.
 El-Assy AY, Clark JA. (1988) Thermal analysis of a flat-plate collector in multiphase flows, including superheat. Solar Energy, 40(4):345-361.
 El-Assy AY, Clark JA. (1989) Thermal analysis of a flat-plate boiling collector having sub-cooled inlet and saturated exit states. Solar Energy, 42(2):121-132.
 Freeman TL, Mitchell JW, Audit TE. (1979) Performance of combined solar-heat pump systems. Solar Energy, 22(2):125-135.
 O'Dell MP, Mitchell JW, Beckman WA. (1984) Design method and performance of heat pumps with refrigerant filled solar collectors. Journal of Solar Energy Engineering, 106(2):159-164.
 Kishore VVN, Gandhi MR, Rao KS. (1984) Analysis of flat-plate collectors charged with phase-changing fluids. Applied Energy, 17(2):133-149.
 Ramos E, Sen M, TreviÃ±o C. (1985) A steady-state analysis for variable area one- and two-phase thermosyphon loops. International Journal of Heat and Mass Transfer, 28(9):1711-1719.
 Mathur GD, McDonald TW. (1986) Simulation program for a two-phase thermosyphon loop heat exchanger. ASHRAE Transcations, 92:473-485.
 Price HW, Klein SA, Beckman WA. (1986) Analysis of boiling flat-plate collectors. Journal Solar Energy Engineering, 108(2):150-158.
 Yilmaz T. (1991) Computer simulation of two-phase flow thermosyphon solar water heating system. Energy Conversion and Management, 32(2):133-144.
 Morrison GL, Gilliaert D. (1992) Unglazed solar collector performance characteristics. Journal of Solar Energy Engineering, 114(3):194-200.
 Radhwan AM, Zaki GM. (1993) Analysis of refrigerant-charged s olar collectors with phase change. Heat Recovery Systems and CHP, 13(5):429-439.
 Torres Reyes E, Picon Nunez M, Cervantes JG. (1998) Exergy analysis and optimization of a solar-assisted heat pump. Energy, 23(4):337-344.
 Cervantes JG, Torres-Reyes E. (2002) Experiments on a solar-assisted heat pump and an exergy analysis of the system. Applied Thermal Engineering, 22(12):1289-1297.
 Hussein HMS, Mohamad MA, El-Asfouri AS. (1999) Transient investigation of a thermosyphon flat-plate solar collector. Applied Thermal Engineering, 19(7):789-800.
 Hussein HMS. (2002) Transient investigation of a two-phase closed thermosyphon flat plate solar water heater. Energy Conversion and Management, 43(18):2479-2492.
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