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.

A multi-stacked heat exchanger comprises a first heat exchanger and a second heat exchanger. A first end of the first heat exchanger receives a first fluid in a first conduit flowing in a first direction within a plane. A first end of the second heat exchanger receives the first fluid from the first heat exchanger in a second direction flowing opposite to the first direction within the plane. A flow of a second fluid is communicated through the second heat exchanger and then through the first heat exchanger, in a second direction orthogonal to the first direction. The second fluid is in thermal communication with the first fluid in the second heat exchanger and then in the first heat exchanger. By doubling the flowed first fluid back upon itself, embodiments achieve counterflow between the first fluid and second fluid within a compact space.

A container for warming fluids comprises an inlet port, an outlet port, a fluid conduit configured for fluidly communicating the inlet and outlet ports, and deflection sections. The fluid conduit has a non-constant maximum width in a direction of fluid flow through the fluid conduit. The deflection sections further comprise an entry section and an exit section, each respective exit section being arranged downstream, in the direction of fluid flow, from each respective entry section. The maximum width of the fluid conduit decreases along the direction of fluid flow through the entry section over a first distance and the maximum width of the fluid conduit increases along the direction of fluid flow through the exit section over a second, different distance. A blood treatment apparatus including the above-described container is also provided.

A heat exchanger includes a distributor, and a first heat transfer tube and a second heat transfer tube connected in parallel with each other with respect to the distributor. The first heat transfer tube is disposed above the second heat transfer tube. The first heat transfer tube has a first inner circumferential surface, and at least one first groove recessed relative to the first inner circumferential surface and arranged side by side in a circumferential direction of the heat transfer tube. The second heat transfer tube has a second inner circumferential surface, and at least one second groove recessed relative to the second inner circumferential surface and arranged side by side in a circumferential direction. An internal pressure loss of the first heat transfer tube is smaller than an internal pressure loss of the second heat transfer tube.

An un-finned heat exchanger (100). The heat exchanger (100) comprises: a heat exchange tube (1), which comprises a body; a fluid channel (11) formed inside the body; and a collecting tube (2) connected to the heat exchange tube (1). Using the heat exchanger can reduce accumulation of dirt on the heat exchanger.

A heat exchanger includes plural heat exchanger cores, each of which includes plural tabular fins with notches formed therein and plural heat transfer tubes. The plural fins are disposed such that planes of the fins face each other. The plural heat transfer tubes are hairpin tubes each of which is bent in a U-shape. The hairpin tubes are placed in the notches in the fins so as to extend in a direction crossing the planes of the fins. The plural heat exchanger cores are placed side by side in a direction crossing the direction of the notches in the fins and at the same time a direction along the planes of the fins. A brazing sheet is disposed between adjacent ones of the heat exchanger cores. The adjacent ones of the heat exchanger cores are brazed together by the brazing sheet.

A heat transfer fin according to the present disclosure includes a fin body and a plurality of through-holes formed through the fin body and spaced apart from each other in a first direction. When a flow direction of combustion gas that is to flow along a surface of the fin body is referred to as a second direction, the fin body includes a distal surrounding part that surrounds a first distal area located at the farthest upstream side of each of the through-holes. The shortest distance between an inner and an outer boundary of the distal surrounding part that is obtained in an area of the distal surrounding part located at the farthest upstream side is smaller than the shortest distance between the inner and the outer boundary that is obtained in an area of the distal surrounding part located at the farthest downstream side.

The present disclosure relates to a heat exchanger including a tube having a length, and a cross-sectional geometry defined by an inner boundary and an outer boundary extending along the length. The tube is configured to flow a refrigerant fluid within the inner boundary to transfer heat. The cross-sectional geometry varies at respective transition points along the length of the tube. The tube is seamless and undeformed at the transition points.

An air-conditioning apparatus, including: a heat source-side heat exchanger including a plurality of heat transfer tubes each having a flattened shape and being arranged in parallel, the heat source-side heat exchanger being used at least as a condenser of a refrigeration cycle; and an outdoor fan for generating flows of air passing through the heat source-side heat exchanger in a predetermined air velocity distribution. The heat source-side heat exchanger is configured to exchange heat between the air and refrigerant flowing through the heat transfer tubes and includes a plurality of refrigerant paths, each including at least one of the plurality of heat transfer tubes and a plurality of two-phase paths for allowing gas refrigerant to flow into and out as two-phase refrigerant; and a plurality of liquid-phase paths for allowing the two-phase refrigerant flowing out of the plurality of two-phase paths to flow out as subcooled liquid refrigerant.

Heat exchanger fins and heat exchangers are disclosed. The heat exchanger fins disclosed herein comprise louvers and winglet-type vortex generators arranged to improve heat transfer efficiency.