Thermal analysis and modeling study of an activated carbon solar adsorption icemaker: Dhahran case study Naef A.A. Qasem, Maged A.I. El-Shaarawi ⇑ Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia article info Article history: Received 11 February 2015 Accepted 20 April 2015 Available online 21 May 2015 Keywords: Solar energy Adsorption Refrigeration Thermodynamic analysis Modeling Activated carbon/methanol abstract Intermittent adsorption refrigeration systems are suitable for producing ice in remote areas. EES and MATLAB computer programs are exploited to analyze the thermodynamic cycle and to model the system under Dhahran climate conditions, respectively. The results show that the system performance in winter is better than in summer under the climate conditions for the city of Dhahran, Saudi Arabia. For example, the system produces below 3 kg in the hot days and more than 5 kg of ice per square meter of solar col- lector in the cold days with solar coefficient of performance (SCOP) that varies between 0.077 and 0.17, respectively. Ó 2015 Published by Elsevier Ltd. 1. Introduction Refrigeration and air conditioning demands are widely increas- ing because of the increase in population as well as the standard and comfort of living and the dramatic growth of industries. The majority of the cooling systems are driven by electric energy while electricity may not cover all the human living areas such as a coun- tryside of some developing countries. Therefore, people living in such areas may not be able to preserve their food and store vacci- nes in their local clinics. Accordingly, solar adsorption refrigeration technology has attracted some research interests since 1990 because it is clean and simple for use in air conditioning, ice mak- ing, food preservation and vaccine storage. The idea of these devices is the reversible physical sorption of a vapor on the surface of a porous solid (desorption of the refrigerant when exposed to heat and adsorption of it during cooling). An intermittent adsorp- tive solar icemaker is an attractive application that is composed of adsorbent bed as adsorptive reactor integrated into a solar collector for desorption of the sorbent material during the day. During the night, adsorption occurs by the adsorbent bed when the refrigerant comes back from the evaporator, in which the cooling effect is obtained and some ice may be produced. The important working pairs studied in the literature as absorbent/adsorbate for adsorption cooling were investigated and compared by Critoph [1], San and Lin [2] and Wang et al. [3]. Additionally, Askalany et al. [4] revised several refrigerants that work with carbon adsorbent while a lot of adsorption refrigeration materials are carefully reviewed by Alghoul et al. [5]. Activated carbon with methanol as a working pair is broadly used in adsorption refrigeration due to the large adsorption quan- tity and low desorption heat, which is about 1800–2000 kJ kg 1 [4]. The adsorbent (solid porous material) properties indicate that the activated carbon is a good choice for adsorption cooling because of its high capacity for desorption and adsorption reaches 0.45 kg kg 1 [6]. Moreover, the system of activated carbon metha- nol needs low grade heat source, which is suitable to work by solar energy. Actually, the activated carbon exists in several forms such powders, granulated, molecular sieves and carbon fibers, Srivastava and Eames [7]. On the other hand, methanol operates at sub atmospheric pressure; the low-pressure systems require a good manufacturing for avoiding leakage, which significantly affects the performance and can shut down the system working. Another deficiency is that the methanol is not compatible with copper at temperatures greater than 120 °C [5] and it decomposes at 150 °C to formaldehyde (HCHO) or dimethyl ether (CH 3 OCH 3 ) by the mechanism of dehydrogenation or dehydration [8]. The decomposition reaction of methanol with aluminum alloy is greater than the copper [8]. Many researches in the literature conducted with adsorption refrigeration through either theoretical analysis or prototypes experimental works or the both. Theoretical and experimental heat and mass transfer in an adsorbent bed for a flat plate solar adsorp- tion icemaker were studied by use 10 kg of Methanol and 42 kg of activated carbon in a rectangular adsorbent bed of 1.5 m 2 solar http://dx.doi.org/10.1016/j.enconman.2015.04.054 0196-8904/Ó 2015 Published by Elsevier Ltd. ⇑ Corresponding author at: Box: 1893, KFUPM, Dhahran 31261, Saudi Arabia. Fax: +966 38602949. E-mail address: magedas@kfupm.edu.sa (M.A.I. El-Shaarawi). Energy Conversion and Management 100 (2015) 310–323 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman