REGENERATOR FOR A THERMAL CYCLE ENGINE

Abstract

The regenerator has a central axis. The regenerator has a multitude of web layers wound around the central axis. The web layers are formed by two or more metal fiber or metal wire having webs wound around the central axis. When observed from the central axis to the outside of the regenerator, at least one web layer of a web of a first width is followed by a web layer of a web of a width larger than the web of a first width.

Claims

1-15. (canceled)

16. A regenerator for a thermal cycle engine, wherein the regenerator has a central axis; wherein the regenerator comprises a multitude of web layers wound around the central axis; wherein the web layers are formed by two or more metal fiber or metal wire comprising webs wound around the central axis; wherein when observed from the central axis to the outside of the regenerator, at least one web layer of a web of a first width is followed by a web layer of a web of a width larger than the web of a first width.

17. The regenerator as in claim 16, wherein when observed from the central axis to the outside of the regenerator, the width of the web forming the first web layer of the regenerator and the width of the web forming the last web layer of the regenerator are larger than the width of a web forming intermediate web layers in the regenerator.

18. The regenerator as in claim 16, wherein a number of web layers are formed by web of a first width wound around the central axis, with in between these web layers, web layers are formed by web of larger width than the web of a first width wound around the central axis.

19. The regenerator as in claim 16, wherein the side ends of web layers of webs of different widths are aligned at one end of the regenerator.

20. The regenerator as in claim 16, wherein the regenerator has over its axial length a constant cross sectional shape and size.

21. The regenerator as in claim 16, wherein the open surface area of the cross section of the regenerator available for working fluid to flow is lower at one end than at the other end of the regenerator.

22. The regenerator as in claim 16, wherein the regenerator has over its axial length different levels of porosity.

23. The regenerator as claim 16, wherein the regenerator does not comprise metallic bonds between the metal fibers or metal wires of the webs.

24. The regenerator as in claim 16, wherein the regenerator comprises metallic bonds between the metal fibers or metal wires of the different webs in the regenerator.

25. The regenerator as in claim 16, wherein the web layers are formed by metal fiber comprising webs and wherein the metal fibers in the metal fiber comprising webs have an average length of at least 12 mm.

26. A method to manufacture a regenerator for a thermal cycle engine as in claim 16, comprising the steps of providing two or more webs comprising metal fibers or metal wires, wherein webs of a number of different widths are provided; winding the webs around a shaft or a core, thereby building up web layers of the web or webs being wound; wherein after forming a web layer by winding a web of a first width, a web layer is formed from a web of a width larger than the web of a first width.

27. The method as in claim 26, wherein the width of the web first wound and the width of the web last wound are larger than the width of at least one web wound in between.

28. The method as in claim 26, wherein a number of web layers are formed by winding webs of a first width, and in between these web layers, web layers are formed by winding webs of larger width than the webs of a first width.

29. The method as in claim 26, comprising the additional step of bringing the regenerator to shape.

30. A thermal cycle engine comprising a regenerator as in claim 16, wherein the cross section of the regenerator has at its hot side a larger area of voids between the metal fibers or metal wires for fluid to flow than at its cold side.

Description

BRIEF DESCRIPTION OF FIGURES IN THE DRAWINGS

[0042] FIG. 1 shows a regenerator ring according to the invention.

[0043] FIG. 2 shows another regenerator ring according to the invention.

[0044] FIG. 3 shows the layer built up of the regenerator rings of FIGS. 1 and 2.

MODE(S) FOR CARRYING OUT THE INVENTION

[0045] FIG. 1 shows an example 100 of a regenerator ring according to the invention. The regenerator has a central axis of symmetry 101. The regenerator has over its axial length H.sub.1 a constant cross sectional shape and size. The regenerator ring has an axial length H.sub.1, e.g. 72 mm. The inner diameter is ID, e.g. 143 mm and the outer diameter is OD, e.g. 221 mm. The regenerator ring has three sections with different porosity levels, a first section 103 with a length H.sub.3, e.g. of 48 mm of a first porosity of e.g. 90%, a second section 105 with a length H.sub.2-H.sub.3 (e.g. 60 mm-48 mm=12 mm) of a higher porosity than the first porosity, e.g. 92.4%; and a third section 107 with a length H.sub.1-H.sub.2 (e.g. 72 mm-60 mm=12 mm) of a still higher porosity, e.g. 94.6%.

[0046] FIG. 2 shows another example 200 of a regenerator ring according to the invention. The regenerator has a central axis of symmetry 201. The regenerator has over its axial length H.sub.1, e.g. 72 mm, different cross sectional shapes and sizes. The inner diameter is ID, e.g. 143 mm. Over a first length H.sub.3, e.g. 48 mm, the regenerator has an outer diameter OD.sub.1, e.g. 221 mm. The outer diameter is then reducing. At a length H.sub.2, e.g. 60 mm, the outer diameter is OD.sub.2, e.g. 205 mm. At the other end of the regenerator (at a length H.sub.1 e.g. 72 mm), the outer diameter is OD.sub.3, e.g. 189 mm. The porosity is substantially constant over the regenerator, and is e.g. 90%.

[0047] Both the regenerators of FIGS. 1 and 2 have been made using the same metal fiber webs. FIG. 3 shows the arrangement of the web layers of the regenerators of FIGS. 1 and 2 (virtually) unwound from the regenerators. FIG. 3 is also illustrating the way the regenerators can be manufactured. Side 26 shows the side of the web layers when starting unwinding the regenerator from the outer diameters. Side 22 shows the side of the web layers at the inner diameter of the regenerator. The way the regenerator is build-up will be explained by describing the way the regenerator has been made.

[0048] The regenerators of FIGS. 1 and 2 can be made in the following way, as illustrated by means of FIG. 3. Three rectangular webs 32, 34 and 36 are provided, wherein two webs 34 and 36 are put on top of web 32 in the way as shown in FIG. 3.

[0049] The first web 32 has a length L.sub.1 of 32.22 m and a width H.sub.1 of 72 mm. On top of it, and at the leading edge 22 of the first web 32 and aligned with the first web 32, the second web 34 is put. The length L.sub.2 of the second web 34 is 13.06 m and its width H.sub.2 is 60 mm. At the end of the length of the second web 34, and on top of the first web 32, the third web 36 is put in the way as indicated in FIG. 3. The third web 36 has a length L.sub.3 of 14.31 m and a width H.sub.3 of 48 mm. When putting the webs on top of each other, there is a certain sticking of the fibers of the different webs, creating cohesion that is helpful when winding the webs. Instead of using webs of the length indicated, web panels of shorter length can be positioned one after the other to obtain the required length of web of a specific width. The three webs 32, 34 and 36 are identical in composition and specific weight. For the examples shown in FIGS. 1 and 2, a carded stainless steel fiber web (bundle drawn AISI 316L steel fibers of 30 m equivalent diameter) of 300 g/m.sup.2 has been used. For the invention, it is also possible to use for the three webs, webs of different composition and/or of different specific weight. Using webs with different properties can facilitate the setting of properties of the regenerator over its axial length.

[0050] The so formed stack of webs 30 is wound around a core of appropriate diameter, starting from the leading edge 22 of the stack of webs. The leading edge 22 is positioned parallel to the core and winding is started. By winding, the web layers of the regenerator ring are formed. Winding stops when the full length of the stack of webs has been wound, ending at edge 26 of the stack of webs 30, which is in this example also the end of the first web 32.

[0051] An alternative approach instead of putting web panels on top of each other is unwinding webs from rolls and winding them together onto a core.

[0052] The wound web layers can then be pressed into a specific shape to form a regenerator. The web layers can be pressed into a shape with constant inner and outer diameter over the axial length of the regenerator, thereby arriving at the regenerator of FIG. 1, with the exemplary dimensions as provided in the description of the regenerator of FIG. 1.

[0053] Alternatively, the web layers can be pressed into a regenerator ring shape that has varying cross section and/or shape over the axial length of the regenerator ring, e.g. the regenerator of FIG. 2, with the exemplary dimensions as provided in the description of the regenerator of FIG. 2.