The performance evaluation of R744 transcritical ejector and R290/R744 cascade refrigeration systems for Turkey

Abstract

In this study, performance of two different environmentally friendly systems with natural refrigerant solutions, R744 transcritical booster system with ejector and a R290/R744 cascade system are examined theoretically by using engineering equation solver software. Operating conditions are determined to represent different climatic regions in Turkey using summer dry bulb temperatures of various cities. The transcritical and the cascade system are assumed to operate at two different evaporation temperatures of-10 °C and-32 °C. The overall energy efficiency ratio values for each system with respect to the same ambient and evaporation conditions are compared and evaluated. Finally, performance of both systems has been compared and the appropriate solution for each city has been suggested. For cold and mild climate regions of Turkey, the performance of transcritical alternative is found better than the proposed cascade system. Moreover, the performance of transcritical system is observed slightly lower than those of the cascade system in hot climate regions of Turkey such as Aegean, Mediterranean, and SouthEast Anatolian regions. It is also found that the performance of the transcritical system is better in regions having lower ambient conditions such as near the Black Sea and eastern regions of Turkey. Therefore, for the mild and cold regions of Turkey, the transcritical ejector option is the better alternative due to having higher performance compared to the cascade system.

Thermodynamic and Environmental Analysis of Novel Cascade Refrigeration Cycles with Ejector and Intercooler for Ultralow Temperatures Using Eco‐Friendly Refrigerants

“…[ 30 ] The equation m ref × (240s) is used to calculate the charge of each refrigerant entering the circuit. [ 31 ] The mass flow rate values of RE170/R170 for CVCRC, CERC, CEBRC, and CEIRC were determined as (0.04378/0.029) kg s −1 , (0.07047/0.05003) kg s −1 , (0.07091/0.05351) kg s −1 , (0.1378/0.101) kg s −1 , respectively, for the selected refrigeration capacity of 10 kW at and −80 °C evaporator temperature and 30 °C condenser temperature. Each pair of cases was treated, and the refrigerant details for TEWI evaluation are listed in Table 2.…”

“…[30] The equation m ref  (240s) is used to calculate the charge of each refrigerant entering the circuit. [31] The mass flow rate values of RE170/R170 for CVCRC, CERC, CEBRC, and CEIRC were determined as (0.04378/0.029) kg s À1 , (0.07047/0.05003) kg s À1 , Bold Values represent the total value of the parameters.…”

Particle image velocimetry as a teaching with technology resource in oscillatory laminar fluid flow

“…They continue to be employed and upgraded, mainly due to their reliability and accuracy when taking vector flow measurements in studies of dynamic situations. Examples of PIV methodology applied to oscillatory flows can be found in [4][5][6][7][8]. Unsurprisingly, this methodology has also spread into pedagogical contexts, mainly in the form of commercially distributed PIV systems such as FLOWCOACH and ePiv [9][10][11][12][13].…”

Modelación de sistemas de refrigeración basados en R744 (CO2) para supermercados en Chile.

“…En la bibliografía, la mayoría de los estudios sobre refrigeración en supermercados se desarrollan mediante modelos termodinámicos y simplificados (Fu et al, 2019;Yilmaz et al, 2019), con expresiones ideales para modelar el control de alta presión y los compresores (Huang et al, 2018). Pocos investigadores han introducido métodos de modelado detallados en este campo (Sacasas et al, 2022;Sun et al, 2021).…”