The present invention lies in the field of electrocaloric energy conversion. More specifically, the present invention relates to improvements in systems and methods which employ electrocaloric materials as a source of temperature variation in electrocaloric refrigeration processes. Even more specifically, the present invention relates to the application of electrocaloric materials in combination with a working fluid communicating with a heat source and a heat sink in counter flow.
F.32 International patent
COBISS.SI-ID: 29642791In the recent years, several caloric technologies have been investigated for future refrigeration, heat pumping, air conditioning or even energy harvesting. Many of these technologies suggest the possibility for improvements in energy efficiency, compactness, noise level, as well as a reduction in environmental impacts. Therefore, they represent serious alternatives to the rather mature domain of a vapor-compression technology. Part II reviewed the present status and engineering challenges of different caloric refrigeration and heat pump technologies. It addressed and explained main obstacles and introduced potential solutions, then proposed future research directions and actions needed to overcome existing barriers toward the real market applications. This segment concluded with a presentation of the most interesting market niches for the earlier industrialization of the caloric energy conversion.
B.04 Guest lecture
COBISS.SI-ID: 14660379Cooling systems based on caloric effects show great potential, due to their high efficiencies and the lack of environmentally hazardous substances needed for their operation. In this work a numerical analysis of a cooling system designed for cooling of electronic components based on elastocaloric and electrocaloric effects is performed. A mathematical model and further numerical model, which enables parametric optimization of such a system is developed. The results show that this kind of micro cooling system can have a cooling capacity up to 0,3 W/cm2 and maximum COP values up to 15 at temperature span of around 1 K. With this, we proved the potentials and the limits of caloric micro cooling systems, which could play an important role in cooling of electronic components in the future.
D.10 Educational activities
COBISS.SI-ID: 16397339A research and development on a cooling device based on an active electrocaloric regenerator (AER) made of bulk ceramic material (1- x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN-100xPT) will be presented. For that purpose, a new, 2D transient numerical model of the AER based on the energy equation for the solid electrocaloric material and the heat transfer fluid was developed and implemented in Matlab software. The model allows to investigate the cooling characteristics (temperature span, cooling power and efficiency) of an AER at different operating conditions (mass-flow rate, operating frequency, applied electric field change, etc). In addition, the model includes the impacts of the electrocaloric material’s hysteresis and the electric-energy recovery released during the depolarization (discharging) of the electrocaloric material on the AER performance. The results of the numerical analyses show that the degree of electric energy recovery has a crucial impact on the efficiency of the electrocaloric device. By considering an idealised electric-energy recovery system, the energy efficiency (expressed by the coefficient of performance - COP) of the device could be increased by up to ten times compared to the case of without the energy recovery. A validation of the numerical model was performed through the design, construction and experiments on a new AER cooling device (without electric-energy recovery system). The experimental results revealed a maximum specific cooling power of 16 W kg-1 and a maximum temperature span of 3.1 K. A comparison between the numerical and experimental results shows that model can correctly predicts the trends of cooling characteristics with respect to various operating parameters. On the other hand, there is some deviation between the absolute values of the cooling characteristics calculated with the numerical model and the experimental results. These deviations are mainly due to some effects not included in the numerical model, for example flow maldistribution.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 16378907