ShareUK: Transcritical CO2 for Harrods
The world-famous London luxury store Harrods has installed an innovative parallel CO2 compression refrigeration system in its food department in order to replace its ageing R22 and R404A systems.
The world-famous London luxury store Harrods has installed an innovative parallel CO2 compression refrigeration system in its food department in order to replace its ageing R22 and R404A systems.
The purpose-built plant room houses three high-temperature/low-temperature (HT/LT) transcritical R744 systems which deliver 160 kW each, enough to cool all the cold rooms and more. In a normal CO2 transcritical system, the flash gas is passed through a pressure reducing valve and fed to the main compressor suction port at a pressure of 27 bar. In this parallel compression system, it is fed into a separate compressor operating a suction pressure of 37 bar, resulting in 40-45% of the total refrigerant flow being compressed through a pressure ratio of 2.43:1 instead of 3.33:1 with a significant overall reduction in compressor power input. Waste heat generated by the system is used to heat water for the store.
The system was nominated in several categories of the 2012 CIBSE Building Performance Awards.
The purpose-built plant room houses three high-temperature/low-temperature (HT/LT) transcritical R744 systems which deliver 160 kW each, enough to cool all the cold rooms and more. In a normal CO2 transcritical system, the flash gas is passed through a pressure reducing valve and fed to the main compressor suction port at a pressure of 27 bar. In this parallel compression system, it is fed into a separate compressor operating a suction pressure of 37 bar, resulting in 40-45% of the total refrigerant flow being compressed through a pressure ratio of 2.43:1 instead of 3.33:1 with a significant overall reduction in compressor power input. Waste heat generated by the system is used to heat water for the store.
The system was nominated in several categories of the 2012 CIBSE Building Performance Awards.