Kamil Bojdo and Piotr WALĄG
University of Agriculture in Krakow, Mickiewicza Krakow, Poland
The biggest environmental problem of conventional refrigeration is the release and leakage of refrigerants into the environment and their subsequent disposal. Hence, the resulting environmental costs create a necessary need to search for new refrigeration techniques that can be used primarily by households. One of the innovations in refrigeration technology is the solution using thermoelectric elements such as the Peltier module. However, the biggest limitation in the large-scale application of this new cooling technique is currently (today) its low efficiency, which is measured in cooling appliances by the COP index (the ratio of the cooling power to the power consumed by the cooling appliance).
The aim of the research in this paper is to analyse how to achieve the highest possible COP by using a Peltier module. In order to optimise the performance of the cooling system, reference was made to COP values having qualitative characteristics, hence this coefficient is the main criterion for determining performance levels in cooling systems. The operating parameters which influence the COP of a cooling system are mainly the power (voltage and current) consumed by the Peltier element and the fans, and the ambient temperature.
On the basis of the analysis of the results from the conducted research, it is justified to state that in the Petier module there is a significant heating of all heat dissipating components in the flat heat sink system (these are the limited possibilities of this type of cell cooling design). Therefore, in order to achieve the highest possible coefficient of cooling efficiency (COP) of the system, other solutions of heat extraction from Peltier modules should be tested and heat losses connected with the insulation of the cooling chamber should be reduced. On the other hand, since the research carried out has shown that the Peltier modules achieve the best cooling capacity for low operating parameters, it is recommended to oversize the cooling unit.