Özet:

Today, cooling systems are needed to work efficiently at low temperatures for reasons such as vaccination storage, fast freezing systems, storage of frozen foods. The use of single-step cooling systems is not economical in terms of energy efficiency and therefore two-step or cascade systems are preferred in cooling applications where low-temperature hands are desired. In addition, two evaporating cooling systems with two different low temperatures are also preferred in many applications. In this study, thermodynamic analysis was carried out in the case of the use of two evaporators in the cascade cooling system and the optimum design parameters were determined in terms of the heating temperature (T_MY) in the cascade coating and the cooling performance ratio (COP). In the cascade cooling system, artificial cooling fluids that cause global warming and ozon layer decay will be used from natural cooling fluids, carbon dioxide (CO2) in low-temperature circle and ammonia (NH3) in high-temperature circle. The cooling capacity is considered stable for both evaporators. As the design parameters, the first and second evaporator temperatures (T_b1,T_b2), the freezing temperature (T_y) and the temperature difference (∆T) in the cascade freezing were addressed and worked for -35 °C to -45 °C, -45 °C to -55 °C, 35 °C to 45 °C, 3 °C to 5 °C values respectively. The results showed that the COP value was largely dependent on the evaporating temperature and that the COP value could reach 2.566 in the studied intervals.

Anahtar Kelimeler: