Energy Conversion and Management, Vol.186, 120-130, 2019
Employing thermoelectric generator and booster compressor for performance improvement of a geothermal driven combined power and ejector-refrigeration cycle
This paper aims at performance improvement of conventional combined power and ejector refrigeration (CPER) system driven by geothermal energy. To do so, two novel systems are proposed and their performance is modeled, investigated and compared with each other as well as with the conventional CPER system. In the proposed systems a booster compressor is employed between the evaporator and ejector to increase the output cooling, and thermoelectric generator (TEG) is employed for waste heat recovery to increase the output power. To analyze the conventional and the proposed CPER systems from the energy and exergy perspectives, thermodynamic models are developed, after which a comprehensive parametric study is conducted to examine the effects of design/operating variables on the systems' performance. The results revealed that, proposed booster assisted system incorporated with TEG has a significantly better performance than the conventional CPER system in terms of output power and cooling as well as energy and exergy efficiencies. However, the proposed booster assisted system without incorporating TEG has a lower values of output power and exergy efficiency than the conventional CPER system, while it yields higher values of output cooling and energy efficiency. It is found that, the booster assisted system incorporated with TEG yields higher exergy efficiency by around 18.7% than the conventional CPER system.
Keywords:Combined power and cooling;Ejector;Booster compressor;Thermoelectric generator;Geothermal energy;Exergy analysis