A heat exchanger (1) for thermally coupling a first fluid to a second fluid so as to transfer heat and in a fluidically separate manner includes a securing assembly (8) of two cover parts (9) and at least one, preferably a plurality of guide parts (11), through which duct tubes (5) of the heat exchanger (1) pass. The duct tubes (5) extend inside a housing tube (2) along the longitudinal axis of the housing tube (2). The first fluid passes through the housing tube (2) outside of the duct tubes (5), and the second fluid passes through the duct tubes (5). The duct tubes (5) may have circular or flattened cross-sections.

A heat exchanger and heat exchanger core are provided. The heat exchanger core includes a plurality of columnar passages extending between an inlet plenum of the heat exchanger core and an outlet plenum of the heat exchanger core, the columnar passages formed monolithically in a single fabrication process.

Heat exchangers, heat exchanger systems, and hypersonic vehicles are provided. For example, a heat exchanger is provided that comprises a first chamber for receipt of a flow of cool fluid and a second chamber for receipt of a flow of hot fluid. The heat exchanger further comprises a buffer fluid flowpath for circulation of a buffer fluid therethrough. The buffer fluid circulates within the buffer fluid flowpath disposed between the first chamber and the second chamber to transfer heat from the hot fluid to the cool fluid. In certain embodiments, a hypersonic vehicle comprises such a heat exchanger, and the cool fluid is cryogenic or near-cryogenic fuel of the hypersonic vehicle and the hot fluid is engine bleed air from a hypersonic propulsion engine of the vehicle.

A heat exchanger includes a first fluid pathway enclosed in a heat exchanger body to convey a first fluid through the heat exchanger body and a second fluid pathway enclosed in the heat exchanger body to convey a second fluid through the heat exchanger body and facilitate thermal energy exchange between the first fluid and the second fluid. The first fluid pathway and the second fluid pathway together are arranged in a spiral arrangement extending along a central axis of the heat exchanger.

A header for a high-pressure heat exchanger includes a first high-pressure transition section with inlets for multiple first high-pressure flow channels that are spaced from one another in a radial direction and collectively arranged in a substantially circular shape. The inlets for the multiple first high-pressure flow channels on a radially outer edge of the first high-pressure transition section are spaced further apart in a circumferential direction from adjacent inlets of the multiple first high-pressure flow channels than radially inward inlets are spaced from adjacent radially inward inlets of the multiple first high-pressure flow channels. The header also includes multiple first high-pressure flow channels extending from the first high-pressure transition section to a second-high pressure transition section that is configured to divide each of the multiple first high-pressure flow channels into at least two first high-pressure sub-flow channels. Each flow channel of the multiple first high-pressure flow channels and each sub-flow channel of the first high-pressure sub-flow channels have a round cross-sectional shape.

A heat exchanger includes a first fluid pathway enclosed in a heat exchanger body to convey a first fluid through the heat exchanger body and a second fluid pathway enclosed in the heat exchanger body to convey a second fluid through the heat exchanger body and facilitate thermal energy exchange between the first fluid and the second fluid. The first fluid pathway and the second fluid pathway together are arranged in a spiral arrangement extending along a central axis of the heat exchanger.

In one instance, a multistage microchannel condenser is provided for use as an aspect of a heating, ventilating, and air conditioning (HVAC) system. The multistage microchannel condenser includes at least two pluralities of flat tubes having microchannels, each associated with a different refrigeration circuit, that are interspersed so that when only one refrigeration circuit is operational, the multistage microchannel condenser still does not have any substantial thermal dead spots. Manifolds are used on each end of the multistage microchannel condenser to fluidly couple members of the at least two pluralities of flat tubes such that the refrigerant in each refrigeration circuit remains separated while still using a majority of the area of the face of the multistage microchannel condenser. Other aspects are presented.

A heat exchanger includes a core and a header tank. The header tank includes a partition, a first inlet pipe, and a second inlet pipe. The partition divides an inside passage of the header tank into a first tank and a second tank. The first inlet pipe introduces a first fluid into the first tank. The second inlet pipe introduces a second fluid into the second tank. The first inlet pipe is inclined at a predetermined angle except a right angle relative to an outer surface of the header tank such that a flow direction of the first fluid flowing from the first inlet pipe to the first tank includes a component in a predetermined direction from a first end of the first tank provided with the partition to a second end of the first tank opposite to the first end.

A heat exchanger for a gas turbine engine includes a heat exchanger body having a first surface and a second surface oriented at least partially at an oblique angle relative to the first surface. The heat exchanger body defines a plenum extending between the first and second surfaces. Furthermore, the heat exchanger body defines a fluid passage extending through the second surface such that the fluid passage is in fluid communication with the plenum. The fluid passage, in turn, includes first and second portions. The first portion intersects the plenum at an intersection and defines a line of projection extending normal to the second surface. The second portion defines a line of projection extending normal to the first surface. The fluid passage further includes a curved portion extending from the first portion to the second portion.

A heat exchanger includes a core. The core includes a first layer and a second layer. The first layer includes a first plurality of fluid inlets. The second layer includes a second plurality of fluid inlets. The heat exchanger also includes a fluid header attached to the core adjacent the first plurality of fluid inlets and the second plurality of fluid inlets. The fluid header includes an inlet, an outlet, a plenum between the inlet and the outlet, and a flow control mechanism within the plenum. The flow control mechanism selectively directs fluid through the first plurality of fluid inlets, through the second plurality of fluid inlets, or through both the first plurality of fluid inlets and the second plurality of fluid inlets.