[EN] The performance of vapor-compression systems working with subcritical refrigerants varies with the degree of subcooling. There is an optimal subcooling that maximizes efficiency. However, it depends on the operating conditions and the control of the system needs to be adapted. Most of the works available in literature are able to operate in optimal conditions only at the design point or if a system is designed to be able to adapt its subcooling, only complex control algorithms that usually are difficult to set and time-costly, are used. This work focuses on the study of the main variables influencing the optimal subcooling and analyzes two different control methodologies from the theoretical point of view. Based on the theoretical study a final control strategy is selected and tested experimentally. The reliability, stability and robustness of the selected strategy are experimentally demonstrated for a wide set of operating conditions. (c) 2018 Elsevier Ltd and IIR. All rights reserved.Part of the work presented was carried by Estefania Hervas Blasco with the financial support of a PhD scholarship from the Spanish government SFPI1500 x 074478XV0. The authors would like also to acknowledge the Spanish 'MINISTERIO DE ECONOMIA Y COMPETITIVIDAD', through the project. "MAXIMIZACION DE LA EFICIENCIA Y MINIMIZACION DEL IMPACTO AMBIENTAL DE BOMBAS DE CALOR PARA LA DESCARBONIZACION DE LA CALEFACCION/ACS EN LOS EDIFICIOS DECONSUMO CASI NULO" with the reference ENE2017-83665-C2-1-P for the given support.Hervas-Blasco, E.; Pitarch, M.; Navarro-Peris, E.; Corberán, JM. (2018). Study of different subcooling control strategies in order to enhance the performance of a heat pump. International Journal of Refrigeration. 88:324-336. https://doi.org/10.1016/j.ijrefrig.2018.02.003S3243368
