Energetic, exergetic and exergoeconomic assessment of transcritical CO2 reversible system combined with dedicated mechanical subcooling (DMS) for residential heating and cooling

Numerical performance of a water source transcritical CO2 heat pump with mechanical subcooling

“…Dai et al have published different papers in which they have numerically studied DMS systems from different perspectives and using R1234yf as refrigerant in the auxiliary cycle [20][21][22][23][24]. In [20,21] As pointed out by Mohammadi [5], above the critical pressure there is no real subcooling and therefore the term "subcooling" should not be used.…”

“…Dai et al have published different papers in which they have numerically studied DMS systems from different perspectives and using R1234yf as refrigerant in the auxiliary cycle [20][21][22][23][24]. In [20,21] As pointed out by Mohammadi [5], above the critical pressure there is no real subcooling and therefore the term "subcooling" should not be used. Despite the authors acknowledging that, from a thermodynamic point of view, it would be more appropriate to use the term "after-cooling", the term "subcooling" is widely used in most of the published research work dealing with transcritical refrigeration and heat pump systems and this work will follow that nomenclature.…”

Impact of an internal heat exchanger on a transcritical CO2 heat pump under optimal pressure conditions

“…Different methods can be considered to improve the COP of a CO 2 transcritical cycle, both in the heating and the refrigeration cycle, in most cases focused on achieving a certain level of subcooling at the gas cooler outlet. One of the most investigated techniques is Dedicated Mechanical Subcooling (DMS) [5,6]. D'Agaro et al [6] show a great effectiveness of DMS when compared with other alternatives.…”

Thermodynamic, economic, and environmental analyses of various novel ejector refrigeration subcooled transcritical CO 2 systems

“…Nebot‐Andrés et al 20 experimentally optimized the gas cooler pressure of mechanical subcooled CO 2 refrigeration system. Recently, some exergy, economic, thermoeconomic, and environmental assessments were withal conducted on this system 21‐23 . Nebot‐Andres et al 24 used a mechanical subcooler and showed that the optimum pressure is dependent on the gas cooler exit temperature but independent of the level of evaporation.…”