Featured Application: Novel combined ORC-VCR cycle and its comparison with usual ORC-VCR cycle are explained. Performance of different working fluids is investigated. Effects of various operational parameters on system performance are shown.Abstract: This paper presents energy and exergy analysis of two vapor compression refrigeration cycles powered by organic Rankine cycle. Refrigeration cycle of combined system was designed with single and dual evaporators. R134a, R1234ze(E), R227ea, and R600a fluids were used as working fluids in combined systems. Influences of different parameters such as evaporator, condenser, boiler temperatures, and turbine and compressor isentropic efficiencies on COP sys and η ex,sys were analyzed. Second law efficiency, degree of thermodynamic perfection, exergy destruction rate, and exergy destruction ratio were detected for each component in systems. R600a was determined as the most efficient working fluid for proposed systems. Both COP sys and η ex,sys of combined ORC-single evaporator VCR cycle was detected to be higher than the system with dual evaporator.

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Gelişmekte olan ülkemizde, artan enerji talebinin karşılanması için yeni yatırımlar yapılmakla beraber, mevcut enerji kapasitesinin tasarruflu ve verimli kullanılmasına yönelik çalışmalar hız kazanmıştır. Bu çerçevede beyaz eşyalarda enerji sınıflandırılmaları yapılarak, elektrik tüketimi az olan cihazların üretimleri gerçekleştirilmiştir. Bu çalışmada, farklı beyaz eşya markalarına ait çamaşır makinesi, kurutma makinesi, buzdolabı ve derin dondurucu ürünlerinin enerji sınıflandırmaları, elektrik tüketim değerleri ve fiyat değişimleri incelenmiştir. Sonuçlarda, daha verimli cihazların satış fiyatlarının yüksek olduğu, elektrik tüketimi yüksek ürünlere göre geri ödeme sürelerinin 6 yıl-18,5 yıl aralığında değiştiği görülmüştür.

The use of new generation low GWP refrigerants in cooling systems is becoming increasingly common due to thermal performance and less environmental impact. In this study, the thermal performance of the new generation R290 refrigerant and the old generation R404A refrigerant in the same cooling system were investigated experimentally and numerically. The thermal performance values of both gases were compared, provided that the temperature of the cold room cooled by the vapor compression cooling system drops to 0?C. -5?C, 0?C, 5?C evaporator temperatures and 25?C, 30?C, 35?C condenser temperatures were used as operating parameters. The experimental results revealed that the highest COP values in the system for R290 and R404A were 4.68 and 3.94, respectively. An average of 9.38 % increase in cooling capacity was detected with R290 compared to R404A refrigerant. In the numerical analysis part of the study, the evaporator surface temperature and air velocity distributions of both refrigerants in the cold room were shown numerically by using Ansys Fluent 19.1. As a result of the study, it was stated that R290 had higher thermal performance than R404A, according to both experimental and numerical analysis results.