During the last decade, the progressive phase-out of high GWP refrigerants has shifted the refrigerant options towards natural or HFOs refrigerants. In light of this trend, it is worthwhile to investigate and optimize refrigeration systems, focusing on HFO alternatives with acceptable GWP levels, as well as other natural refrigerant options. To accomplish this goal, refirming current designs and investigating alternative solutions are essential. This involves conducting thermal system simulations to thoroughly assess systems from thermodynamic (energy efficiency) and dynamic/control ( dynamics, thermal responses) perspectives. The authors have developed/adapted Modelica models to analyse road transport refrigeration units. Firstly, the numerical model is introduced and validated using empirical data from a refrigeration system utilizing a blend of HFCs/HFOs (R452A). Subsequently, the model is applied to conduct numerical simulations. On one hand, the impact of using an internal heat exchanger is assessed, revealing a potential increase in cooling capacity of up to 11 %. On the other hand, the impact of switching to a hydrocarbon (R290) is analyzed, revealing an increased cooling capacity of up to 7% compared to R452A.

Project CPP2021-009066 funded by MCIN/ AEI /10.13039/501100011033 and by European Union NextGenerationEU/ PRTR. Carles Oliet, as a Serra Hunter Associate Professor, acknowledges the Catalan Government for the support through this Program.