© JUN 2019 | IRE Journals | Volume 2 Issue 12 | ISSN: 2456-8880 IRE 1701278 ICONIC RESEARCH AND ENGINEERING JOURNALS 65 Development of a Model for Design of Double - Effect Vapor Absorption Refrigeration Systems M. A. AKINTUNDE 1 , F. H. ADEDOYIN 2 , K. A. ADETORO 3 1, 2 Department of Mechanical Engineering, Federal University of Technology, Akure. P. M. B. 704, Ondo State Nigeria. 3 Department of Mechanical Engineering, Osun State Polytechnic, Ire Abstract- Increasing cost of electricity and environmental degradation, emanates from the usage CFC refrigerants have made the heat from renewable energy sources for absorption refrigeration systems attractive for application in residential, commercial and industrial sectors. In this research work, mathematical model for a double effect reserve – parallel vapour absorption refrigeration system was developed. Software was developed for the system using MATLAB Programming Language. The software was simulated and design parameters needed for the analysis of the system were generated. The model was validated by comparing its result with those from literature and showed good agreement with an average deviation of 20%. The model was used to estimate both refrigeration capacity and the coefficient of performance (COP). Highest COP was obtained when the concentration of the diluted solution in the evaporator was 62.2%. Generally the COP increases with increasing concentration of the solution in the absorber. The software developed can be used to predict design parameters for double- effect reverse-parallel VARS over a wide range of heat input. Indexed Terms- design, double-effect, reverse- parallel, software, VARS. I. INTRODUCTION Absorption refrigeration systems used various combinations of two chemical compounds, known as refrigerant and absorbent for operations. The absorbent absorbs the refrigerant vapour, without any chemical reaction between them at all working conditions; and releases the refrigerant when heated. The combination of refrigerant and absorbent is call fluid pair (Renjith and Joshy, 1999). Absorption systems use heat energy to produce refrigeration as well as heating if required. In LiBr/H2O system, water is the refrigerant and aqueous Lithium Bromide (LiBr) is widely used as the carrier to absorb the refrigerant and provide a higher coefficient of performance (Wang and Lavan, 1999). Vapour absorption refrigeration system (VARS) belong to the class of vapour cycles similar to vapour compression systems. However, unlike vapour compression refrigeration system, the required input to absorption system is in the form of heat. Similar to vapour compression refrigeration systems, VARS have in various refrigeration and air conditioning applications. Since these systems run low-grade thermal energy, they are preferred when low-grade energy, such as waste heat or solar energy is available. Conventional absorption systems use natural refrigerants such as water or ammonia that are environment friendly. Absorption refrigerator typically operates with relatively low quality heat energy. Therefore they can be powered using heat rejected or wasted by many industrial processes. Thus the waste heat energy can be converted to useful energy to power refrigerating systems. The use of waste heat energy can therefore cut global CO2 emissions and reduce the global warming problem. According to Vliet et al.; (1982), the performance of single-effect absorption cycle can be further improved by accommodating a second generator, as in the case of double-effect. A VARS having two generators is known as double-effect absorption system. Double- effect LiBr – H2O systems have proved to have significant higher COP than single effect but they need high driving temperature (Grossman, 2002). Many different thermodynamic cycles have been proposed, but the LiBr – H2O pair is one of the most interesting. The refrigerant absorbent pair H2O – LiBr, according to Asdrubali and Grignaffini, (2005) has numerous advantages such as high enthalpy of vaporization, no