Thermodynamic analysis of novel multi stage multi effect metal hydride based thermodynamic system for simultaneous cooling, heat pumping and heat transformation

Abstract

Metal hydride based heat transformer, heat pumping and cooling systems are the most important thermodynamic applications of metal hydrides due to the ability to utilise waste heat as input. For attaining higher efficiency and extensive operating temperature range, novel four alloys multi stage multi effect thermodynamic system is proposed. This paper brings systematic study of four alloys based thermodynamic cycle for simultaneous cooling, heat pumping and heat transformation. The performance of this thermodynamic cycle was studied using different combination of AB5 – type (La and Mm based) metal hydrides. The effect of operating temperatures (such as hot, driving, intermediate and cold temperatures) and different metal hydride combinations on the thermodynamic cycle performance was studied. Additionally, the cycle performance i.e. coefficient of performance (COP), specific alloy output (S), cooling capacity (CC), etc. were compared with three alloys based simultaneous heating and cooling system. The study shows that the employment of four alloy system for the development of metal hydride based thermodynamic system improves cycle efficiency as well as specific alloy output and facilitates extensive operating temperature range. © 2016 Hydrogen Energy Publications LLC