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    Experimental investigation of performance of vapor ejector refrigeration system using refrigerant R123
    (PERGAMON-ELSEVIER SCIENCE LTD, 2008) Yapici, Rafet
    In the present study, a novel ejector was designed based oil a constant area ejector model and manufactured in order to investigate the performance of an ejector refrigeration system in a wider operating range. The ejector, with movable primary nozzle, was mounted oil the system that was previously constructed for low pressure refrigerants. The modified refrigeration system has been tested using hot water as driving fluid and R123 as working fluid. The effects of the operating temperatures oil the cooling capacity and performance coefficient of the system were investigated experimentally when the primary nozzle position was optimum at the ejector area ratio of 9.97. As a result, a performance coefficient of 0.39 was obtained at the vapor generator temperature 98 degrees C, the evaporator temperature 10 degrees C and critical condenser pressure 129 kPa. (C) 2007 Elsevier Ltd. All rights reserved.
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    Performance of a solar ejector cooling-system in the southern region of Turkey
    (ELSEVIER SCI LTD, 2007) Ersoy, H. Kursad; Yalcin, Sakir; Yapici, Rafet; Ozgoren, Muammer
    Performance variations of a solar-powered ejector cooling-system (SECS) using an evacuated-tube collector are presented for Antalya, Aydin, Konya and Urfa cities located in the southern region of Turkey by means of hourly and monthly average ambient temperature and solar radiation meteorological data. A SECS, based on a constant-area ejector flow model and using R-123, was considered. The cooling season and period were taken into account for the 6 months (May-October) and the hours 8:00-17:00, respectively. It was found that the evacuated-tube collector efficiency depending upon the ambient temperature and solar radiation within the day was remarkably varied. However, for all the cities, the cooling capacities of the SECS were very similar. When generator, condenser, and evaporator temperatures were taken, namely, 85 degrees C, 30 degrees C and 12 degrees C, the maximum 2 overall coefficient of performance and the cooling capacity were obtained as 0.197 and 178.26 W/m(2) respectively, at 12:00 in August for Aydin. The evacuated-tube collector area per ton cooling was found to be around 21 m(2) at. noontime in August for all the cities. Furthermore, at the off-design conditions, a performance map of the system was derived and discussed. It was determined that the SECS could be used for office-cooling purposes during the hours (8:00-15:00) in the southern region of Turkey. (c) 2006 Elsevier Ltd. All rights reserved.