Abstract: A tube bundle heat exchanger having a tube sheet, an outer shell and an interior. The heat exchanger includes a tube bundle having tubes located in the interior for fluid flow. The tubes have outside ribs and a channel is formed between adjacent ribs. The tube sheet has openings as passage points. Outer fins of the tubes project into the openings, and a joint gap is formed between an inner surface defining the opening and the outer fins of a tube located therein. The tubes are bonded to the tube sheet by joining material with the involvement of the outer fins. The bond is only formed in a first portion of the opening. The first portion is filled with joining material such that a second portion of the opening remains which is not filled with joining material, and the tube has outer fins adjacent the second portion.

Abstract: A cooling system for the liquid immersion cooling of electronic components. The cooling system includes a container having a container wall and, in the interior, a reservoir for liquid heat transfer fluid in which positioning devices for electronic components are arranged. The container has a gas chamber for gaseous heat transfer fluid. In the gas chamber of the container, there is a heat exchanger device with heat exchanger tubes for liquefying gaseous heat transfer fluid, the heat exchanger tubes having outer fins on their outer sides. The heat exchanger tubes pass into the container wall or through the container wall at passage points. The heat exchanger tubes have an integral bond with the container wall at these passage points.