A plate fin heat exchanger includes adjacent flow paths that transfer heat from a hot flow to a cooling flow. The flow paths are defined by a combination of plates and fins that are arranged to transfer heat from one flow to another flow. The plates and fins are created from sheet metal material brazed together to define the different flow paths. Thermal gradients present in the sheet material create stresses that can be very high in certain locations. The stresses are typically largest in one corner where the hot side flow first meets the coldest portion of the cooling flow. In an opposite corner where the coldest hot side flow meets the hottest cold side flow the temperature difference is much less resulting in unbalanced stresses across the heat exchanger structure. Increasing temperatures and pressures can result in stresses on the structure that can exceed material and assembly capabilities.
Turbine engine manufactures utilize heat exchangers throughout the engine to cool and condition airflow for cooling and other operational needs. Improvements to turbine engines have enabled increases in operational temperatures and pressures. The increases in temperatures and pressures improve engine efficiency but also increase demands on all engine components including heat exchangers.
Turbine engine manufacturers continue to seek further improvements to engine performance including improvements to thermal, transfer and propulsive efficiencies.
In a featured embodiment, a plate fin heat exchanger includes a first cast plate assembly includes at least two plate portions separated by at least one cooling channel. Each of the two plate portions include a plurality of internal passages extending between a corresponding plurality of inlets and outlets. A common inlet perimeter surrounds the plurality of inlets from each of the two plate portions and an outlet perimeter surrounds the plurality of outlets from each of the two plate portions. An inlet manifold is attached at an inlet joint to the inlet perimeter. An outlet manifold is attached at an outlet joint to the outlet perimeter.
In another embodiment according to the previous embodiment, a second cast plate assembly includes a second inlet perimeter attached to the outlet perimeter of the first cast plate assembly at an intermediate joint and the outlet manifold is attached to the outlet perimeter of the second cast plate assembly.
In another embodiment according to any of the previous embodiments, the first cast plate assembly includes a plurality of fin portions that extend from top and bottom surface of the plate portions.
In another embodiment according to any of the previous embodiments, at least one additional cast plate assembly with an inlet perimeter is attached at an additional inlet joint to the inlet manifold and an outlet perimeter is attached at an additional inlet joint to the outlet manifold.
In another embodiment according to any of the previous embodiments, the inlet manifold and the outlet manifold include a first passage in communication with the first cast plate assembly and a second passage in communication with the second cast plate assembly.
In another embodiment according to any of the previous embodiments, the at least two plate portions include three plate portions including a top plate portion, an intermediate plate portion and bottom plate portion with a cooling channel defined on either side of the intermediate plate portion.
In another embodiment according to any of the previous embodiments, the at least two plate portions include four plate portions including a top plate portion, a first intermediate plate portion, a second intermediate plate portion and a bottom plate portion with the cooling channel defined between the plate portions.
In another embodiment according to any of the previous embodiments, the inlet joint includes a brazed joint between the inlet perimeter and an internal surface of the inlet manifold and the outlet joint includes a brazed joint between the outlet perimeter and an internal surface of the outlet manifold.
In another embodiment according to any of the previous embodiments, the common inlet perimeter and the common outlet perimeter include smooth surfaces on outer surfaces of opposing distal ends.
In another embodiment according to any of the previous embodiments, the common inlet perimeter and the common outlet perimeter are parts separate from the first cast plate assembly.
In another embodiment according to any of the previous embodiments, the common inlet perimeter and the common outlet perimeter are integral parts of the first cast plate assembly.
In another embodiment according to any of the previous embodiments, the cast plate assembly includes a single unitary cast item.
In another featured embodiment, a plate fin heat exchanger includes a first cast plate assembly including at least two plate portions separated by at least one cooling channel. Each of the two plate portions include a plurality of internal passages extending between a corresponding plurality of inlets and outlets. An inlet perimeter surrounds the plurality of inlets from each of the two plate portions and an outlet perimeter surrounds the plurality of outlets from each of the two plate portions. A second cast plate assembly includes at least two second plate portions separated by at least one second cooling channel. Each of the two second plate portions include a second plurality of internal passages extending between a second corresponding plurality of inlets and outlets. The second cast plate assembly includes a second inlet perimeter surrounding the second plurality of inlets of the second cast plate that is attached to the outlet perimeter of the first cast plate assembly. An inlet manifold is attached at an inlet joint to the first inlet perimeter of the first cast plate assembly. An outlet manifold is attached at an outlet joint to the outlet perimeter of the second cast plate assembly.
In another embodiment according to the previous embodiment, the first cast plate assembly and the second cast plate assembly both include a plurality of fin portions that extend from top and bottom surfaces of the plate portions.
In another embodiment according to any of the previous embodiments, the inlet perimeter and the outlet perimeter are parts separate from the first cast plate assembly and the second cast plate assembly.
In another embodiment according to any of the previous embodiments, the inlet perimeter and the outlet perimeter are integral parts of the first cast plate assembly and the second cast plate assembly.
In another embodiment according to any of the previous embodiments, first cast plate assembly and the second cast plate assembly each include separate unitary cast items.
In another featured embodiment, a method of assembling a heat exchanger includes joining a first cast plate assembly to an inlet manifold at an inlet joint. The first cast plate assembly includes at least two plate portions separated by at least one cooling channel to an inlet manifold. Each of the at least two plate portions include a plurality of internal passages extending between a corresponding plurality of inlets and outlets and an inlet perimeter surrounds the plurality of inlets from each of the two plate portions and an outlet perimeter surrounds outlets from each of the two plate portions. An outlet manifold is joined at an outlet joint to the outlet perimeter of the first cast plate assembly.
In another embodiment according to the previous embodiment, second cast plate assembly is joined between the first cast plate and the outlet manifold. The second cast plate is identical to the first cast plate and a second inlet perimeter of the second cast plate is joined to the first outlet perimeter of the first cast plate at an intermediate joint and a second outlet perimeter of the second cast plate is jointed at the outlet joint to the outlet manifold.
In another embodiment according to any of the previous embodiments, the first cast plate and the second cast plate both include a plurality of fin portions extending from top and bottom surfaces of the at least two plate portions.
In another embodiment according to any of the previous embodiments, first cast plate assembly and the second cast plate assembly each include separate unitary cast items.
Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.
These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description.
Referring to
Each of the cast plates 12, 58 includes a leading edge 30, a top surface 34, a bottom surface 36 and a trailing edge 32. Cooling airflow 44 enters cooling channels 22 disposed between plate portions 14 defined as part each of cast plates 12, 58. Fin portions 24 extend from top and bottom surfaces of each of the plate portions 14.
Referring to
The plurality of fins portions 24 extend from top and bottom surfaces 34, 36 of each of the plate portions 14. The cooling airflow through the cooling channels 22 flows between the plurality of fin portions 24 disposed on each of the plate portions 14.
The disclosed example cast plate 12 includes four plate portions 14 that define internal passages 16. Between the plate portions 14 are the cooling channels 22 for the cooling air flow 44. In this example there are three cooling channels 22 disposed between the four plate portions 14. Cooling air flow 44 will also flow over the top and bottom of the cast plate 12.
The plurality of inlets 18 and the plurality of outlets 20 are surrounded by a corresponding inlet perimeter and outlet perimeter 26, 28. The inlet perimeter 26 surrounds and defines an outer border around the inlets 18 on the common inlet face 27. The outlet perimeter 28 surrounds and defines an outer border around the outlets 20 on the common outlet face 25. The outlet perimeter 28 includes a smooth machined or ground surface that mates with an inner surface of the exhaust manifold 40.
Referring to
It should be appreciated that although identical plates are shown and disclosed by way of example that different cast plates 12 can be used to address application specific requirements.
In this example each of the intake manifold 38 and the exhaust manifold 40 includes separate sections illustrated at 62. Although not shown, the intake manifold 38 includes separate sections similar to those shown in the exhaust manifold 40. Each of the separate sections 62 correspond to one of the separate cast plates 12, 58 mated to the either the inlet manifold 38 or the outlet manifold 40. Although the example inlet manifold 38 and exhaust manifold 40 are shown and disclosed by way of example as including separate sections 62, a single open area to each of the inlet manifold 38 and exhaust manifold could also be utilized and is within the contemplation of this disclosure. Moreover, any combination of separate sections would also work with the cast plates 12, 58 disclosed by way of example.
The example heat exchanger 15 includes three first cast plates 12 stacked one on top of the other that are joined to the inlet manifold 38 at one of the separate portions 62. Each of the inlet manifold 38 and the exhaust manifold 40 includes the interior mating surface 60 that receives a corresponding one of the cast plates 12, 58.
As appreciated the example heat exchanger illustrated in
Referring to
The joints 50, 52, 54, 50′, 52′ and 54′ are disclosed by way of example as brazed joints. However, other joining and welding processes and method as are known could be utilized and are within the contemplation of this disclosure. For example, friction welding, laser welding and plasma welding may be utilized for form one or all of the disclosed joints. Additionally, the number of joints required to form the disclosed example heat exchangers are significantly reduced as compared to traditional heat exchanger construction and therefore enables the use of welding, brazing techniques not previously practical.
Referring to
Referring to
Both cast plates 64 and 66 include inlet perimeters 78 and outlet perimeters 80 that surround the corresponding inlet face 70 and outlet face 72. The perimeters 78, 80 provide a surface for forming a desired joint with another cast plate or a manifold.
Each of disclosed cast plates 12, 58, 12′, 58′, 64 and 66 are single one piece unitary cast structures that are formed complete with internal passages, fin portions and perimeters. Secondary machining to refine the joint surfaces defined at the perimeters is all that may be desired. The inclusion of the fin portion with the plate portions as a casting eliminates many joints that can complicate assembly and limit operational capabilities.
Referring to
In this disclosed example, the first cast plate 92 and the second cast plate are identically shaped and configured cast structures. Once the intermediate joint 110 is complete, the exhaust manifold 108 is joined at an outlet joint 104 as indicated at 97. The outlet joint 104 is also a brazed or welded joint between the outlet perimeter 102 and an inner surface of the exhaust manifold 108. Accordingly, the disclosed heat exchangers can be constructed with a minimal number of joints.
Moreover, the disclosed example heat exchangers maybe scaled up or down depending on application specific requirements by adding additional cast plates that are joined to corresponding manifolds in a serial or parallel manner.
Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this disclosure.