COOP Norge operates over 900 supermarkets in Norway. To improve their distribution centre productivity the business required a new fully automated distribution centre. The 51,000m2 distribution centre with chamber heights up to 27m has been built near Oslo airport. The building consists of fifteen warehouse chambers with product storage temperatures ranging from -25oC to +25oC, plus banana ripening chambers and four separate office locations spread around the building. The majority of the warehouse chambers require both cooling; this is due to the high level of automation; and heating due to the -30oC outside temperatures seen in winter. COOP required the building cooling & heating solution to have low operating and capital cost. GSE Norway, the main contractor, employed Star Technical Solutions to carryout the following work during the 3 year build project:
- Refrigeration feasibility study to determine the most effect method of cooling & heating the warehouses.
- CFD modelling of two chilled chambers to identify the refrigeration requirements, to allow two product ranges, with differing storage temperature needs, to be stored at different heights within the same chamber. The 0oC to +2oC products are stored below 6m and +2oC to +4oC products are stored from 6m to 22m.
- Detailed refrigeration tender technical specification.
- Tender review of prospective contractors for the refrigeration systems.
- Continuous review of the refrigeration system detailed technical design and installation.
- Review of the design and installation of the freezer insulated envelope.
- Dehumidification of narrow voids between freezer area and concrete firewalls.
The refrigeration system specified and installed for the building cooling & heating system uses ammonia as the primary refrigerant, with +6oC glycol for the chambers ranging from +13oC to +25oC, offices and banana ripening chambers, -6oC glycol for chambers ranging from 0oC to +7oC and a CO2 low stage system for the -10oC and -25oC chambers. A +20oC warm glycol circuit is used to heat the 0oC to +25oC chambers, providing defrost heating for 0oC to +5oC chambers and is used as a heat source for each of the office fluid heat pumps. The +20oC warm glycol circuit generates its heat from that rejected by the refrigeration system. However, as back up there is a 1000kW glycol electric heater available, for when there is not enough heat been generated from the refrigeration system.