Energetic and exergetic performance investigation of a solar based integrated system for cogeneration of power and cooling

• Published in: Applied thermal engineering Vol. 112; pp. 1305 - 1316
• Main Author: Khaliq, Abdul
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05.02.2017; Elsevier BV
• Subjects: Cogeneration; Combined power and cooling; Cooling; Cooling systems; Ejection; Energy distribution; Energy management; Evaporation; Exergy; Inlet pressure; Irreversibility; Parametric analysis; Power efficiency; R-141b; Rankine cycle; Refrigeration; Solar energy; Solar generators; Solar power tower; Stress concentration; Studies; Systems integration; Thermodynamics; Solar power tower; R-141b; Irreversibility; Exergy; Combined power and cooling
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2016.10.127

•A solar based R141b operated combined power and cooling cycle is proposed.•The cycle performances are evaluated theoretically using energy and exergy methods.•Local irreversibility of the components of the cycle are computed and investigated.•Expander inlet pressure and condenser temperature have a strong effect on cycle performance.•Most local irreversibility occurs in the central receiver, heliostat, HRVG and ejector. Combining the ejector with organic Rankine cycle has shown potential improvements in the efficiency. However, a solar based combined power and cooling cycle is still a subject for further study. Evaluating the efficiency of this cycle is made difficult by the fact that there are two different simultaneous outputs, namely power and refrigeration. In this paper, the first and second laws of thermodynamics are used to assess the performance of a novel solar based integrated system which produces two different simultaneous outputs using R141b as a working fluid. A mathematical model based on exergy method is introduced to evaluate the local irreversibility in each component of the integrated system. It is shown that the central receiver and heliostat are the biggest source of irreversibility followed by the HRVG, ejector and condenser. Both energy and exergy efficiencies of the integrated system and exergy loss distributions of solar heat input are computed and compared with energy distribution. Parametric analysis of the results shows that expander inlet pressure, condenser temperature, evaporator temperature, and expander back pressure have a strong effect on the power output, refrigeration capacity, and on the energy and exergy efficiency of the proposed system.