Innovative fully integrated transcritical R744 refrigeration systems for a HFC-free future of supermarkets in warm and hot climates

Abstract

General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Pressure Exchanger for Energy Recovery in a Trans-Critical CO2 Refrigeration System

“…This leads to lower system performance at warmer ambient conditions and higher expansion losses, respectively. However, researchers are continuously improving refrigeration technology to overcome the lower system performance in warm and hot climates [3]. Figure 1a shows a typical CO 2 vapor compression cycle.…”

An experimental investigation of performance and instabilities of the R744 vapour compression rack equipped with a two-phase ejector based on short-term, long-term and unsteady operations

“…The energy performance improvement of both configurations facilitates utilisation in cold and moderate climate zones, and the R744 booster supermarket system with gas removal can achieve up to a 35% COP improvement [13]. However, the significant COP degradation of R744-based systems at transcritical conditions has forced an implementation of efficient devices and enhanced system configuration [14].…”

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

“…Se consideró que cada válvula de expansión es capaz de mantener un sobrecalentamiento constante en el evaporador de 10K, como suponen muchos autores (Gullo, 2019). Este sobrecalentamiento considera dos sobrecalentamientos: uno interno útil de 5K y otro de 5K en la línea de succión.…”

“…Como asumen muchos autores (Gullo, 2019;Gullo et al, 2018bGullo et al, , 2017a, en los sistemas de refrigeración, la presión de condensación es controlada a temperaturas ambiente inferiores a 15 o 20°C para garantizar una diferencia de presión mínima a través de la válvula de expansión. Una diferencia de presión demasiado baja implica un menor flujo másico de refrigerante suministrado al evaporador, reduciéndose la demanda de refrigeración.…”

“…Al igual que en el estudio de Gullo (2019), se obtuvo una tendencia decreciente para la temperatura de aproximación del enfriador de gas (Fig. 14b), que varía entre 2.7°C y 3.8°C.…”