Expansion unit for a vapour compression system

Abstract

An expansion device unit () for a vapor compression system (), and a vapor compression system () are disclosed. The expansion device unit () comprises an inlet opening () arranged to receive fluid medium, at least two outlet openings () arranged to deliver fluid medium, a main expanding section () adapted to expand fluid medium received via the inlet opening () before delivering the fluid medium to the outlet openings (), and a distribution section () arranged to split the fluid flow received via the inlet opening () into at least two fluid flows to be delivered via the outlet openings (). The main expanding section () and/or the distribution section () is/are arranged to cause pressures in fluid delivered via at least two of the outlet openings () to be distinct. The main expanding section () is operated on the basis of one or more parameters measured in the fluid flow delivered by one of the outlet openings (). The distinct pressure levels allow distinct evaporating temperature in evaporator paths () connected to the outlet openings (). Thereby a large temperature difference between inlet temperature and outlet temperature of a secondary fluid flow across the evaporator () can be obtained, without requiring that the entire mass flow must be compressed from a low pressure level by the compressor (). Thereby energy is conserved.