TY - JOUR 
A1 - Sánchez Velasco, Francisco Javier
AU - Haddouche, Mohammed Reda
AU - Illán Gómez, Fernando
AU - García Cascales, José Ramón
T1 - Experimental characterization of the coupling and heating performance of a CO2 water-to-water heat pump and a water storage tank for domestic hot water production system
Y1 - 2022
SN - 1872-6178
UR - http://hdl.handle.net/10317/12129
AB - This work presents an experimental study of the dynamic performance of a CO2 water-to-water heat pump in a domestic hot water production system. A facility was developed and used to characterize the time evolution of the COP of this heat pump, the heating and stratification processes of the hot-water storage tank, and the global COP of the system. Results showed that, when heating the water storage tank, strategies based on promoting stratification to reach Ri ∼40, such as the use of vertical tank filling velocities  ∼ 10-4 m·s−1 with low water flow rates between the tank and the heat pump gas cooler, permits an increase of ∼12.4% in the system global COP and a reduction of ∼16% of the compressor energy consumption compared to other strategies. However, strategies based on considering higher water flow rates (i.e. Ri ∼1) increase the thermal energy available in the tank (∼6% when flow rate and increases a factor 3.6) but enhance the water mixing and extend the heating time which reduces the global COP of the system. Besides, an increase of the evaporator inlet water temperature from 5 °C to 20 °C increases the system global COP by 59% and reduces the heating time ∼40%.
KW - Mecánica de Fluidos
KW - Heat pump
KW - Storage tank
KW - Hot water production
KW - CO2
KW - 3309.95 Transmisión de Calor en Refrigeración y Calefacción
KW - 2204.04 Mecánica de Fluidos
LA - eng
PB - ELSEVIER
ER -