Spyros Kalyvas
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Spyros Kalyvas has a total of 6 co-authors. Here are the top co-authors by number of shared publications:
- Antonios Charalampidis
Laboratory of Steam Boilers and Thermal Plants, National Technical University of Athens, 15780 Athens, Greece
1 shared publication - Efstratios Varvagiannis
Laboratory of Thermal Processes, National Technical University of Athens, 15780 Zografou, Greece
1 shared publication - Gabriel Palamidis
Laboratory of Thermal Processes, National Technical University of Athens, 15780 Zografou, Greece
1 shared publication - Konstantinos Braimakis
Laboratory of Refrigeration, Air-Conditioning and Solar Energy, School of Mechanical Engineering, National Technical University of Athens, 15772 Athens, Greece
1 shared publication - Sotirios Karellas
Laboratory of Thermal Processes, National Technical University of Athens, 15780 Zografou, Greece
1 shared publication - Tryfon C. Roumpedakis
Laboratory of Applied Thermodynamics, School of Mechanical Engineering, National Technical University of Athens, 15780 Athens, Greece
1 shared publication
Latest Publications
- Open Access
Experimental Evaluation of a Solar Ejector Cooling Cycle Prototype
Ejector-based cooling systems have gathered scientific interest as a low-cost alternative for solar-assisted cooling applications, especially in regions with solar abundance. This work presents the experimental investigation of a solar ejector cooling prototype system. The system, developed at the National Technical University of Athens, includes a custom-made ejector and is powered by a 48 m2 flat plate solar collector field, assisted by an auxiliary natural gas boiler. Experimental testing under varying operating conditions was conducted to assess the system’s performance, focusing on the influence of evaporation and condensation temperatures. The maximum coefficient of performance (COP) was measured at approximately 0.160–0.165, corresponding to an entrainment ratio of 0.19 at an evaporation temperature of 9 °C and condensation temperatures of 26–27 °C. Ejector performance substantially declined with increased condensation temperatures. However, the influence of the evaporator pressure on system performance was less significant. These findings demonstrate the feasibility of ejector-based solar cooling as a sustainable solution for reducing electricity use in cooling applications, highlighting the critical influence of operating parameters in the system’s performance optimization.
Open AccessExperimental Evaluation of a Solar Ejector Cooling Cycle Prototype
Ejector-based cooling systems have gathered scientific interest as a low-cost alternative for solar-assisted cooling applications, especially in regions with solar abundance. This work presents the experimental investigation of a solar ejector cooling prototype system. The system, developed at the National Technical University of Athens, includes a custom-made ejector and is powered by a 48 m2 flat plate solar collector field, assisted by an auxiliary natural gas boiler. Experimental testing under varying operating conditions was conducted to assess the system’s performance, focusing on the influence of evaporation and condensation temperatures. The maximum coefficient of performance (COP) was measured at approximately 0.160–0.165, corresponding to an entrainment ratio of 0.19 at an evaporation temperature of 9 °C and condensation temperatures of 26–27 °C. Ejector performance substantially declined with increased condensation temperatures. However, the influence of the evaporator pressure on system performance was less significant. These findings demonstrate the feasibility of ejector-based solar cooling as a sustainable solution for reducing electricity use in cooling applications, highlighting the critical influence of operating parameters in the system’s performance optimization.