Carbon dioxide (R744) is widely used as refrigerant in supermarkets located in cold weather sites thanks to its negligible environmental impact and its favourable thermo-physical properties. Due to its low critical temperature, transcritical operations in CO2 refrigeration systems can commonly take place, increasing the energy consumption substantially. On the other hand, the high temperatures reached by the CO2 in the high pressure heat exchanger (gas cooler) potentially allow recovering a large amount of heat at different temperature levels according to the supermarket needs. The paper deals with the energy performance evaluation of a R744 refrigeration system, which provides the selected supermarket with DHW and heating, besides satisfying the cooling load required by the refrigerated and frozen food storage equipment. The system is equipped with an additional air-cooled evaporator which can be used as a supplemental heat source, to increase the amount of heat recovered and meet the full heating demand of the building. Different control strategies are examined in order to minimize the electric consumption and, contemporary, maximize the heat recovery.

Energy analysis of a transcritical CO2 supermarket refrigeration system with heat recovery

POLZOT, Alessio;D'AGARO, Paola;CORTELLA, Giovanni
2017

Abstract

Carbon dioxide (R744) is widely used as refrigerant in supermarkets located in cold weather sites thanks to its negligible environmental impact and its favourable thermo-physical properties. Due to its low critical temperature, transcritical operations in CO2 refrigeration systems can commonly take place, increasing the energy consumption substantially. On the other hand, the high temperatures reached by the CO2 in the high pressure heat exchanger (gas cooler) potentially allow recovering a large amount of heat at different temperature levels according to the supermarket needs. The paper deals with the energy performance evaluation of a R744 refrigeration system, which provides the selected supermarket with DHW and heating, besides satisfying the cooling load required by the refrigerated and frozen food storage equipment. The system is equipped with an additional air-cooled evaporator which can be used as a supplemental heat source, to increase the amount of heat recovered and meet the full heating demand of the building. Different control strategies are examined in order to minimize the electric consumption and, contemporary, maximize the heat recovery.
File in questo prodotto:
File Dimensione Formato  
rj30.pdf

accesso aperto

Tipologia: Versione Editoriale (PDF)
Licenza: Creative commons
Dimensione 420.01 kB
Formato Adobe PDF
420.01 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11390/1100071
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 30
  • ???jsp.display-item.citation.isi??? 26
social impact