Integrated evaporator–condenser cascaded adsorption system for low temperature cooling using different working pairs

• Published in: Applied energy 2017-01, Vol.185, p.2117-2126
• Main Authors: Dakkama, H.J., Elsayed, A., AL-Dadah, R.K., Mahmoud, S.M., Youssef, P.
• Format: Article
• Language: English
• Subjects: Adsorption; Cascading; Freezing; Simulink; Working pairs
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2016.01.132

•Five combinations of working pairs with cascading adsorption system are simulated.•Integrated evaporator–condenser heat exchanger is simulated with the stated system.•The low-temperature heat source is applied to drive the adsorption refrigeration system.•Natural refrigerants are investigated as one of the requirements of this work.•ATO/Ethanol+AC-35/Methanol showed a good performance with the lowest cost. A cascaded adsorption cooling system with an integrated evaporator/condenser can produce low temperature cooling, using waste heat sources. The choice of the working pair in such a system affects the system’s performance when driven by low temperature waste heat sources, which can be as low as 70°C. This paper investigates the performance of various adsorbent/refrigerant working pairs in a cascaded adsorption system with an integrated evaporator/condenser using Simulink/MATLAB software. The cascaded system consists of two pairs of adsorber beds, a condenser, an evaporator and an integrated condenser/evaporator heat exchanger, forming upper and bottoming cycles. Five combinations of working pairs were investigated: ATO/ethanol+Maxsorb/R507A; Maxsorb/R134a+Maxsorb/propane; ATO/Ethanol+Maxsorb/propane; ATO/ethanol+AC-35/methanol; and Maxsorb/R134a+Maxsorb/R507A. The latter combination was used for validation and as a reference combination for assessing the performance of the investigated working pairs in terms of COP and cooling capacity. The results showed that the Maxsorb/R134a+Maxsorb/propane combination gives a higher COP compared to the reference combination, with up to 30.0% and 30.1% for the COP and cooling capacity, respectively; while ATO/ethanol+AC-35/methanol produces a similar performance to the reference case but uses natural refrigerants with low global warming potential and low cost adsorbent materials.