Integrated heating and cooling CO2 heat pump system in a modern distribution centre.

Industry is responsible for about 25-30 % of the global primary energy demand (Elmegaard, Zühlsdorf et al. 2017), and around two thirds of this is used for heating and cooling (Elmegaard, Zühlsdorf et al. 2017). Several recent innovations can improve the thermal energy efficiency and enable smart utilization of sun and/or surplus heat in several plants, yet they are not well-known and therefore rarely used. Novel approaches for supplying heating and cooling by integrated CO2 heat pump systems are presented; including: direct heat exchange with CO2, multiejectors, solutions to avoid implosion in CO2 refrigeration systems at low ambient temperature, integration with high temperature heat pumps (above 100°C), ground condensers and optimal insulation. Some of these technologies are implemented, some are under construction and others still remain at concept level.