TY - JOUR
TI - Thermodynamic analysis of refrigerants used in ORC-VCC combined power systems for low temperature heat sources
AU - Elbir Ahmet
AU - Kodaloglu Feyza Akarslan
AU - Ucgul Ibrahim
AU - Sahin Mehmet Erhan
JN - Thermal Science
PY - 2022
VL - 26
IS - 4
SP - 2855
EP - 2863
PT - Article
AB - Fossil resources are largely used for energy supply. This situation causes  environ­mental pollution. In recent years, studies in the field of more  environmentally friend­ly and sustainable energy conversion technologies  have increased. In this context, organic Rankine cycle (ORC) technology is  combined with RES. In this study, combined ORC and vapor compression cycle  (VCC) were investigated. The electricity produced in the combined ORC-VCC  system was used both in the compressor of the VCC system and in the plant.  The main factor affecting the efficiency of the combined ORC-VCC system is  the refrigerant. Therefore, it is necessary to examine the selection of the  most suitable refrigerant for an ORC-VCC based system. Fifteen different  refrigerants were optimized with the enginering equation solver program, and  energy and exergy analyzes of the systems were made separately. According to  the results, the best energy efficiency and COP values among the  refrigerants was found to be R40 (ηORC = 0.1206) for the ORC system and R113  (COP = 4.405) for the VCC system. For all system components in the VCC, the  most exergy destruction occurs in the evaporator, followed by the  compressor, condenser, and throttle, respectively. In ORC, the most exergy  destruction is in the evaporator, followed by the condenser, tube and pump,  respectively. The total efficiency was found to be (β = 0.53) for the  combined ORC-VCC system. The total exergetic efficiency was found to be  (ψglob = 0.26) for the combined ORC-VCC system.