Efficient NH₃ dry expansion thanks to intelligent planning and modern system components

As part of the consolidation of several locations, REWE Dortmund SE & Co. KG built a new logistics center in Dortmund in 2020. Covering an area of over 45,000 m², it supplies more than 400 REWE stores in the Ruhr, Sauerland and Münsterland regions with fresh goods. The use of modern refrigeration technology saves around 30% energy and CO₂ compared to conventional systems.

Holistic refrigeration planning by cold.world Engineering

cold.world took over the complete planning and technical support of the refrigeration system – from the initial concept idea through to commissioning. In close coordination with the operator, the decision in favor of the natural refrigerant ammonia (NH₃) was made in the early planning phase.

The challenge:

A cooling capacity of around 4 MW was to be provided with a filling quantity of less than 3 tons of ammonia – with the aim of avoiding a complex BImSchG approval procedure.

Our solution:

The choice fell on direct evaporation with NH₃ (ammonia). By dispensing with an NH₃ pump system with flooded evaporation, the total filling volume could be reduced to around a third.

Efficient system components – specifically planned

In order to realize the cooling capacity within the set filling limit, cold.world placed particular focus on the selection of suitable evaporators and condensers, as well as on the exact dimensioning of the pipes and their routes in the building.

A total of 88 evaporators were installed in two different temperature zones.

Result: Efficiency meets sustainability

The planning by cold.world Engineering resulted in an ultra-modern and energy-efficient refrigeration system that meets the high requirements of REWE Dortmund in terms of quality, security of supply and environmental compatibility – without any complex BImSchG procedure.