36 // End User
CO2 rack by Advansor.
of the four CO 2 booster rack systems at the Hamburg logistics facility. Ejector technology has been thriving in Europe thanks to the energy savings it promises. A study, supported by the Swiss Federal Office of Energy (SFOE) and published in 2017 by the German magazine Kälte Klima Aktuell, reports that, “according to estimates, several hundred [CO 2] ejector systems are currently in use, the majority of which are in Europe”. Coop, Switzerland’s second-largest retail chain and the parent company of Transgourmet, has also opted to use ejectors, according to the study. “Refrigeration needs in food markets account for about half of the electricity consumption, which is why the ejector makes a significant contribution to the reduction of energy consumption,” said Thomas Häring, head of energy and technology at Coop, in the report. Transgourmet itself also has previous experience of using ejectors. “We have already put several transcritical CO 2 refrigeration systems with ejectors into operation,” Michael Zammert, who is responsible for purchasing capital goods like refrigeration systems, LED lighting and shelves at Transgourmet, told Accelerate Europe.
The estimated payback time for an ejector is between one and six years depending on the size of the supermarket, according to the report.
Inside the Hamburg facility The low - temperature side of the installation has been running since the beginning of March and the mediumtemperature side since the beginning of April. One of the CO 2 booster systems utilises parallel compressors and the gas and liquid ejectors to provide a further 400 kW for the air conditioning system. Heat recovered from the refrigeration system is used to provide tap water (120 kW at 65-55°C) and space heating (320 kW at 38-25°C), and to defrost the deep-freezer units. A heat pump is also integrated for peak load periods. It uses the ambient air as a heat source via evaporator coils in the gas coolers. The total yearly energy consumption of the system is 2,600,000 kWh.
Zammert told Accelerate Europe. “We can say that all the running has been smooth.” Af te r th e ini tial s ta r tu p p hase , Transgourmet will carry out training. “The personnel responsible will get new training from the manufacturer and will be introduced to all the impor tant par ts of the syste m ,” Zammert says. “Additionally, documents containing CO 2 refrigeration instru ctions and information will be created. These will be integrated in the regular workprotection trainings.” With the use of CO 2 in distribution centres currently being fulfilled as an important part of Transgourmet’s strategy, Accelerate Europe has learned that this will not be the last installation to harness ejectors. “We are currently planning with FrigoConsulting another transcritical CO 2 system with ejectors,” Zammert says. “This will have even more cooling power than the current system in Hamburg. We assume that the handover will be in the summer and will be a new milestone in our plan.” CM
Transgourmet is happy about the running of the installation so far. “This system has been working for a short time now,” Accelerate Europe // Summer 2018