Port opening with supercooling

A plate heat exchanger comprising a number of plates provided with a pressed pattern of ridges and grooves arranged to keep the plates on a distance from one another under formation of interplate flow channels for media to exchange heat with a heat exchange fluid, the interplate flow channels communicating with port openings, and the interplate flow channels include a first interplate flow channel and a second interplate flow channel, wherein the first interplate flow channel is constructed to flow one of the media or the heat exchange fluid therethrough, and the second interplate flow channel is constructed to flow another of the media or the heat exchange fluid therethrough so that the media and the heat exchange fluid do not contact each other, wherein one of the port openings is constructed for connection to a downstream side of an expansion valve such that coolant from the expansion valve may enter one of the interplate flow channels via the one port opening, and wherein a heat exchanging means is provided inside the one port opening, said heat exchanging means being arranged for exchanging heat between coolant downstream of the expansion valve and coolant about to enter the expansion valve.