VANES FOR HEAT EXCHANGERS

A heat exchanger includes a vane positioned between an inlet and an outlet of a heat exchanger manifold. The vane includes a leading edge proximate the inlet and a trailing edge proximate the outlet. The vane includes opposing first and second surfaces between the leading and trailing edges. The first and second surfaces are porous to provide fluidic communication between the first surface and the second surface to resist fluid separation along the first surface and/or the second surface to minimize fluid pressure drop between the inlet and the outlet of the manifold.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to heat exchangers, and, in particular, to vanes for manifolds in heat exchangers.

2. Description of Related Art

Heat exchangers are used in a variety of systems, for example, in engine and environmental control systems of aircraft. These systems tend to require continual improvement in heat transfer performance, reductions in pressure loss, and reductions in size and weight. Heat exchangers can include manifolds leading into and/or out of the heat exchanger core. These manifolds can direct fluid flow into and out of the heat exchanger core and can cause a pressure drop between an inlet pipe and the heat exchanger core.

Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for systems and methods that allow for improved heat exchangers. The present invention provides a solution for these problems.

SUMMARY OF THE INVENTION

A heat exchanger includes a vane positioned between an inlet and an outlet of a heat exchanger manifold. The vane includes a leading edge proximate the inlet and a trailing edge proximate the outlet. The vane includes opposing first and second surfaces between the leading and trailing edges. The first and second surfaces are porous to provide fluidic communication between the first surface and the second surface to resist fluid separation along the first surface and/or the second surface to minimize fluid pressure drop between the inlet and the outlet of the manifold.

A flow path can be defined between the inlet and the outlet of the heat exchanger manifold. The inlet can define an inlet axis substantially parallel to the flow path at the inlet. The outlet can define an outlet axis angled with respect to the inlet axis. In accordance with some embodiments, the porosity of the vane is defined by at least one of a plurality of apertures, a foam structure, slot perforations, hole perforations, and a wire mesh. It is contemplated that the vane can be a first vane and that the heat exchanger can include additional vanes positioned between the inlet and the outlet of the heat exchanger manifold. The additional vanes can be similar to the first vane described above. The first surface can be a concave surface and the second surface can be a convex surface.

The heat exchanger can include a heat exchanger core operatively connected to and in fluid communication with the outlet of the manifold. The heat exchanger can include a second-manifold vane positioned between an inlet and an outlet of a second heat exchanger manifold. The inlet of the second heat exchanger manifold can be operatively connected to an outlet of the heat exchanger core. The second heat exchanger manifold can define a second-manifold flow path between the inlet and the outlet of the second heat exchanger manifold. The inlet of the second heat exchanger manifold can define a second-manifold inlet axis substantially parallel to the second-manifold flow path at the outlet of the heat exchanger core. The outlet of the second heat exchanger manifold can define a second-manifold outlet axis angled with respect to the second-manifold inlet axis. The second-manifold vane can include a leading edge proximate the outlet of the heat exchanger core and a trailing edge proximate the outlet of the second heat exchanger manifold. The second-manifold vane can include porous first and second surfaces, similar to the vane describe above. The porosity of the second-manifold vane can be defined by apertures.

In accordance with some embodiments, the second-manifold vane is a first second-manifold vane. The heat exchanger can include additional second-manifold vanes positioned between an inlet and an outlet of the second heat exchanger manifold. The additional second-manifold vanes can be similar to the first second-manifold vane described above.

In accordance with another aspect, a method of manufacturing a vane for a heat exchanger, similar to the vanes described above, includes forming a vane body having a leading edge and a trailing edge with a first surface and an opposing second surface between the leading and trailing edges. The first and second surfaces are porous to provide fluidic communication between the first surface and the second surface. The forming can be via additive manufacturing, for example, direct metal laser sintering.

These and other features of the systems and methods of the subject invention will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a perspective view of an exemplary embodiment of a heat exchanger in accordance with the disclosure is shown inFIG. 1and is designated generally by reference character100. Other embodiments of heat exchanger100in accordance with the disclosure, or aspects thereof, are provided inFIGS. 2-6, as will be described. The heat exchangers described herein provide for reduced fluid pressure drop and increased flow uniformity as compared with traditional heat exchangers.

As shown inFIG. 1, a heat exchanger100includes vanes102positioned between an inlet104and an outlet106of a heat exchanger manifold108. A flow path110is defined between inlet104and outlet106of heat exchanger manifold108. Inlet104defines an inlet axis A substantially parallel to the flow path at inlet104. Outlet106defines an outlet axis B angled with respect to inlet axis A. In an embodiment, the angle between the inlet axis A and the outlet axis B is about 90 degrees. Each vane102includes a leading edge112proximate inlet104and a trailing edge114proximate outlet106. Each vane102includes opposing first and second surfaces,116and118respectively, between leading and trailing edges,112and114, respectively. First surface116is a concave surface and second surface118is a convex surface. It is contemplated that manifold108can include any suitable number of vanes102, for example, manifold108can include a single vane102or a plurality of vanes102. It is contemplated that vanes can all be porous vanes102, as will be describe below, or the vanes can be a mixture of porous and non-porous vanes. In accordance with an embodiment, it is also contemplated both porous and non-porous sections can be included in a single vane.

With continued reference toFIG. 1, heat exchanger100includes a heat exchanger core122operatively connected to and in fluid communication with outlet106of manifold102. It is contemplated that heat exchanger core122can be a plate-fin heat exchanger core, a counter-flow heat exchanger core, or any other suitable heat exchanger core. Heat exchanger100includes a second-manifold vane102′ positioned between an inlet104′ and an outlet106′ of a second heat exchanger manifold108′. Inlet104′ of second heat exchanger manifold108′ is connected to an outlet107of heat exchanger core122. Second heat exchanger manifold108′ defines a second-manifold flow path110′ between inlet104′ and outlet106′ of second heat exchanger manifold108′. Inlet104′ of the second heat exchanger manifold108′ defines a second-manifold inlet axis C substantially parallel to the second-manifold flow path at outlet107of heat exchanger core122. Outlet106′ of second heat exchanger manifold108′ defines a second-manifold outlet axis D angled with respect to second-manifold inlet axis C. The heat exchanger100being configured, in one embodiment, so that the flow out of the outlet106′ along axis D is substantially180degrees to the flow into the inlet104along axis A.

While vanes102and102′ are shown with varying thicknesses, those skilled in the art will readily appreciate that vanes102and/or102′ can be uniform in thickness. It is contemplated that manifolds108and/or108′ can have a variety of suitable shapes, for example, they can be semi-hemispherical, include a diffuser, or be any other suitable shape or variation depending on the design space provided. Manifolds108and/or108′ and vanes102and/or102′ can be made from a variety of suitable metals or alloys thereof, such as, nickel, copper, titanium, steel, and/or aluminum. In accordance with some embodiments, it is contemplated that the leading and trailing edges of vanes102and/or102′ can begin and end anywhere, as long as at least a portion of a given vane is positioned between the inlet and the outlet. It is also contemplated that the vanes may all be of the same length and spacing, or may have different lengths and spacing to achieve the desired flow distribution with minimal pressure drop.

As shown inFIG. 2, concave and convex surfaces,116and118, respectively, of each vane102, are porous to provide fluidic communication between concave surface116to convex surface118, shown schematically by arrows. The fluid flow from concave surface116to convex surface118acts to resist fluid separation on along convex118surface and minimizes fluid pressure drop between inlet104and outlet106of manifold108. With traditional heat exchanger vanes, fluid flow over the convex side of the vane tends to separate and can result increased pressure loss across the vane, and ultimately can result in increased pressure drop between the inlet and outlet of the manifold. The porosity of vane102acts as a flow control device to minimize separation from convex surface118and reduce the pressure loss across vane102in manifold108while still providing the desired flow distribution into heat exchanger core122. In accordance with the embodiment inFIG. 2, the porosity in vane102is achieved using apertures120between concave and convex surfaces,116and118, respectively.

As shown inFIGS. 3-6, it is contemplated that the porosity of vanes can be achieved with a variety of suitable geometries, for example, vanes can be a perforated sheet with either uniform or non-uniformly spaced holes, slits, or other features. In accordance with some embodiments, vanes202and302are sheets with hole-shaped or slot shaped perforations, shown inFIGS. 3 and 4, respectively. In accordance with the embodiment ofFIG. 5, vanes402resemble the construction of open-cell foam and/or reticulated foam, where pores of the foam allow flow from one surface to the other. As shown in the embodiment ofFIG. 6, vanes502include a wire mesh structure, similar to a metal screen.

With reference now toFIGS. 1 and 2, each of the second-manifold vanes102′ include a respective leading edge112′ proximate outlet107of heat exchanger core122and a respective trailing edge114′ proximate outlet106′ of second heat exchanger manifold108′. Each second-manifold vane102′ includes respective porous concave and convex surfaces,116′ and118′, respectively, similar to vane102describe above. For example, one or more of second-manifold vanes102′ can include apertures, similar to apertures120in vane102, described above. It is contemplated that manifold108′ can include any suitable number of vanes102′, for example, manifold108′ can include a single vane102′ or a plurality of vanes102′. It is contemplated that vanes102′ can all be porous vanes, or vanes102′ can be a mixture of porous and non-porous vanes. In accordance with an embodiment, it is also contemplated that both porous and non-porous sections can be included in a single vane.

In accordance with another aspect, a method of manufacturing a vane, e.g. vanes102and/or102′, for a heat exchanger, e.g. heat exchanger100, includes forming a vane body having a leading edge and a trailing edge, e.g. leading and trailing edges,112/112′ and114/114′, respectively, with a concave surface and an opposing convex surface, e.g. concave and convex surfaces116/116′ and118/118′, respectively, between the leading and trailing edges using additive manufacturing, for example, direct metal laser sintering. It is contemplated that the vanes can be formed in conjunction with their respective heat exchanger manifolds, e.g. heat exchanger manifolds108and/or108′.

While vanes102and102′ are shown and described herein as having an arcuate geometry, it is contemplated that vanes102and102′ do not have to be continuously curved. Vanes102and102′ can include straight sections, be entirely straight, or can create an s-curve, depending on the orientation of the inlet manifold, the core and the outlet manifold. Additionally, it is contemplated that while the flow path at inlet104is shown at ninety degrees with respect to core122, inlet104can be at a variety of angles with respect to core122. For example, they can be in direct alignment or at an angle less than or more then ninety degrees. This similarly can apply to the angle between core122and outlet106′ of second heat exchanger manifold108′.

The methods and systems of the present disclosure, as described above and shown in the drawings, provide for heat exchanger manifolds with vanes having superior properties including reduced pressure drop and flow uniformity. While the apparatus and methods of the subject disclosure have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the spirit and scope of the subject disclosure.