Heat exchanger

A heat exchanger of a loop thermosyphon type comprising:

• a base plate with a first surface for receiving a heat load from one or more electric components,
• an evaporator with evaporator channels, the evaporator being in thermal contact with a second surface of the base plate for transferring said heat load into a first fluid in the evaporator channels,
• a condenser with condenser channels having upper ends for receiving first fluid from upper ends of the evaporator channels and for dissipating heat from the first fluid in the condenser channels, and
• a collector space for receiving first fluid from the condenser, wherein the collector space is located higher than the lower ends of the evaporator channels and is in fluid communication with lower ends of the evaporator channels,
• wherein the evaporator is provided with individual tubes having internal longitudinal walls dividing the tubes into the evaporator channels, and
• wherein the evaporator comprises a plurality of said individual tubes stacked against each other along the second surface of the base plate to be parallel with each other such that the evaporator channels of the tubes extend parallel with each other, and
• wherein the first fluid received from the condenser to the collector space is passed to the lower ends of the evaporator channels in an operating state of the heat exchanger,
• wherein the heat exchanger comprises a chamber in an upper part of the heat exchanger which is in fluid communication with the upper ends of the evaporator channels and with the upper ends of the condenser channels for passing the first fluid from the evaporator to the condenser, and
• wherein the heat exchanger is enclosed by a housing having a first section where the base plate and the evaporator are arranged in a vertical position, and a second section where the condenser is arranged in a vertical position.