Experimental study of the thermodynamic performance of the ORC-VCC system with a zeotropic mixture

•An organic Rankine cycle coupled with vapor compression cycle is established.•Two subsystems share a condenser and a zeotropic mixture is used as working fluid.•Effects of cooling conditions and evaporation temperature are investigated.•The maximum cooling capacity is 3.3 kW with a performance coefficient of 0.21. The organic Rankine cycle-vapor compression cycle is an effective way to improve energy efficiency by converting low-grade heat energy into cold energy. Since the demand for cooling capacity varies with ambient temperature and operating parameters, it is valuable to investigate the off-design performance of the combined system. An experimental apparatus for coupling the organic Rankine cycle with the vapor compression cycle is established in this paper. The two subsystems share a common condenser and a zeotropic mixture is used to reduce the irreversible loss. Off-design experiments are conducted at various cooling water and evaporation temperatures to gain insight into the variations in its performance. The results show that cooling water temperature has a greater impact on system operational characteristics than cooling water flow rate. As the cooling water temperature decreases and its flow rate increases, the cooling capacity of the system increases, while the coefficient of performance changes little. With the increase in cooling water temperature, the isentropic efficiency of the expander and compressor increases to 74.8 % and 72.5 %, respectively. The system has an optimal evaporation temperature to achieve the highest cooling capacity and performance coefficient, with maximum values of 3.3 kW and 0.21, respectively.