Evaporator and heat exchanger with external loop, as well as heat pump system and air conditioning system comprising said evaporator or heat exchanger

An evaporator of plate type having at least one inlet and at least one outlet allowing a medium to enter into and exit from said evaporator, said evaporator comprising:

• a plurality of interconnected evaporation chambers disposed in parallel, having at least one common inlet and at least one common outlet allowing a medium to enter into and exit from said chambers;
• an external loop configured to drain said medium from lower parts of said evaporation chambers and introduce said medium back into the evaporation chambers.

A heat exchanger of plate type comprising:

• interacting alternating plates having a groove pattern forming at least first and second separate duct loop systems allowing a first medium to circulate in the first of said duct systems under heat exchange with a second medium circulating in the second of said duct systems, wherein said first duct loop system comprises a part forming a plurality of interconnected evaporation chambers having at least one common inlet and at least one common outlet allowing said first medium to enter into, and exit from, said chambers,
• wherein said evaporation chambers include an additional outlet connected to a drainage means for said first medium from said evaporation chambers' lower parts in an external loop and to introduce said first medium back into said evaporation chambers.