Heat exchanger

A heat exchanger adapted to be used in a vapor compression system, comprising:

• a shell with a longitudinal center axis extending generally parallel to a horizontal plane;
• a distributing part disposed inside of the shell, and configured and arranged to distribute a refrigerant;
• and
• a tube bundle including a plurality of heat transfer tubes disposed inside of the shell below the distributing part so that the refrigerant discharged from the distributing part is supplied onto the tube bundle, the heat transfer tubes extending generally parallel to the longitudinal center axis of the shell and arranged in a plurality of columns extending parallel to each other when viewed along the longitudinal center axis of the shell, the tube bundle having at least one of
• an arrangement in which a vertical pitch between adjacent ones of the heat transfer tubes in at least one of the columns is larger in an upper region of the tube bundle than in a lower region of the tube bundle, and
• an arrangement in which a horizontal pitch between adjacent ones of the columns is larger in an outer region of the tube bundle than in an inner region of the tube bundle.