An aluminum alloy fin stock material comprising about 0.9-1.2 wt. % Si, 0.3-0.5 wt. % Fe, 0.20-0.40 wt. % Cu, 1.0-1.5 wt. % Mn, 0-0.1% Mg and 0.0-3.0% Zn, with remainder Al and impurities at ≤0.15 wt. %. The aluminum alloy fin stock material is produced in a form of a sheet by a process comprising the steps of direct chill casting an ingot, hot rolling the ingot after the direct chill casting, cold rolling the aluminum alloy to an intermediate thickness, inter-annealing the aluminum alloy cold rolled to an intermediate thickness at a temperature between 200 and 400° C., and cold rolling the material after inter-annealing to achieve % cold work (% CW) of 20 to 40%. The aluminum alloy fin stock material possesses an improved combination of one or more of pre- and/or post-brazes strength, conductivity, sag resistance and corrosion potential. It is useful for fabrication of heat exchanger fins.

A cooling system includes a heat exchanger having one or more rows of multiple flat tubes, louvered fins disposed between pairs of flat tubes, and special header tube connections to form a counter flow heat exchanger. Heat exchangers having multiple rows may be placed near or close to the server racks and may be in fluid communication with an outdoor heat exchanger having one or more rows. A single-phase fluid is pumped through a fluid circuit or loop, which includes the heat exchangers at the server racks and the outdoor heat exchanger. The single-phase fluid circuit including the heat exchangers at the IT racks may alternatively be in thermal communication with a water circuit that includes an outdoor fluid cooler. The flat tubes can be formed tubes with one or more channels, or extruded tubes with multiple channels. The heat exchangers include header tubes/connections, which facilitate easy fabrication and connection between rows and inlet/outlet, and lower the pressure drop.

Each of tanks of a heat exchanger includes a tube joint portion and a tank body portion which define an internal space of the tank. The tube joint portions of the tanks constitute a single core plate. The tank body portions each have a claw protruding toward a core portion. The core plate is provided with a hole that fits with the claw. In a state in which the claw is fitted into the hole, the tank body portions are fixed to the core plate.

A method for joining a first metal part with a second metal part, the metal parts having a solidus temperature above 1100° C., includes applying a melting depressant composition on a surface of the first metal part, the melting depressant composition including a melting depressant component that includes at least 25 wt % boron and silicon for decreasing a melting temperature of the first metal part; bringing the second metal part into contact with the melting depressant composition at a contact point on said surface; heating the first and second metal parts to a temperature above 1100° C.; and allowing a melted metal layer of the first metal component to solidify, such that a joint is obtained at the contact point. The boron at least partly originates from a boron compound selected from any of the following compounds: boric acid, borax, titanium diboride and boron nitride. The melting depressant composition and related products are also described.

A heat exchanger includes: a header; and heat transfer tubes connected to the header. The header includes a first member, a second member, and a third member. A brazing layer between the second member and the third member has a melt rate, at predetermined temperature, that is larger than a melt rate, at the predetermined temperature, of at least one of: a brazing layer between the first member and the second member; and a brazing layer between the first member and the third member.

A plate heat exchanger has two metal plates brought into abutment, with a solder material between the plates. The plates are heated up to a first temperature. The plates are placed into a mold, the mold surfaces of which have cavities for envisaged channel structures. Channel structures are formed by local internal pressure forming of at least one plate under pressurization by the tool. The plates are heated up to a second temperature. The plates are solder bonded at the abuted surfaces. A plate heat exchanger has two metal plates, wherein channel structures have been formed in at least one plate and the plates are bonded to one another by soldering away from the channel structures. Eutectic microstructures having a longest extent of less than 50 micrometers are formed in the solder layer.

A method for manufacturing heat exchangers includes securing a plurality of tubes to first and second header plates such that each tube extends between the first and second header plates and such that each tube is spaced apart from adjacent tubes; disposing a portion of the plurality of fins between adjacent tubes of the plurality of tubes other than a preselected pair adjacent tubes of the plurality of tubes; disposing a spacer between the tubes of the preselected pair adjacent tubes; heating the first and second header plates, the plurality of tubes, the plurality of fins, and the spacer in a brazing furnace such that a brazing material joins the plurality of fins to the plurality of tubes; and dividing each of the first and second header plates between the tubes of the preselected pair of adjacent tubes to form two heat exchangers.

A method for producing a heat exchanger is disclosed. The method includes a) providing two heat exchanger plates of the heat exchanger that are to be joined to one another; b) wetting at least one common local joining zone of the two heat exchanger plates with solder; c) forming the heat exchanger by brazing the two heat exchanger plates via local heating of the at least one common joining zone.

A method for producing a brazed plate heat exchanger comprising a stack of heat exchanger plates provided with a pressed pattern adapted to provide contact points between neighboring heat exchanger plates, such that the heat exchanger plates are kept on a distance from one another under formation of interplate flow channels for media to exchange heat, wherein the interplate flow channels are in selective communication with port openings for the media to exchange heat and circumferentially sealed along an outer periphery in order to avoid external leakage, comprises the following method steps: a. Calculating the position of the contact points between neighboring plates; b. Calculating a force that must be transferred by each contact point when the heat exchanger is in use; c. Based on the method steps above, calculating a necessary amount of brazing material for each contact point; d. Providing a screen for screen printing the brazing material onto the heat exchanger plates, wherein the screen is provided with openings, the size, position, plate thickness and shape of which being adapted to provide the necessary amount of brazing material to each contact point; e. Screen printing the heat exchanger plates with brazing material using the screen; f. Stacking the heat exchanger plates in a stack; and g. Brazing the stack of the heat exchanger plates in order to join the plates together to form the heat exchanger.

Method for brazing or refilling comprising the following steps: providing at least one part (51) containing a metal or metal alloy, for example stainless steel, the part (51) having at least one face (59) defining a plurality of interstices (61) comprising at least two opposite edges separated on the face (59) by a maximum distance of not more than 250 micrometres; obtaining a coating (R) in contact with said face and comprising at least a first layer (85), located at least partially in the interstices, and a second layer (87) adjacent to the first layer, the first layer (85) comprising a first powder (A) containing a metal or metal alloy, the second layer comprising a mixture of a second powder (B) and a third powder (C), the second powder and the third powder being, respectively, different alloys suitable for brazing or refilling the part, and the solidus temperature TSC of the third powder being lower than the solidus temperature TSB of the second powder; heating the part and the coating at a heating temperature strictly lower than the solidus temperature TSA of the first powder, lower than the solidus temperature TSB, and strictly higher than the solidus temperature TSC, and at least partially melting the coating; and cooling the part and the coating to obtain a solidified residue attached to the part.