Claims
- 1. A method for fabricating heat transfer protuberances for conducting heat through a cylindrical wall between a fluid exterior to the cylindrical wall and a working gas interior to the cylindrical wall, the method comprising casting of the cylindrical wall and the heat transfer protuberances in a single operation.
- 2. A method in accordance with claim 1, wherein the step of casting the cylindrical wall and heat transfer protuberances includes at least one of investment casting, sand casting, and die casting.
- 3. A method in accordance with claim 1, further comprising:
a. fabricating a plurality of negative molds, each mold being of a group of substantially parallel holes; and b. assembling the plurality of negative molds to form a negative form for casting the cylindrical wall and heat transfer protuberances.
- 4. A method in accordance with claim 1, further comprising fabricating a single positive form for investment casting, the form having a plurality of groups of substantially parallel heat transfer protuberances.
- 5. A method in accordance with claim 1, further comprising:
a. fabricating a negative mold by die-casting or metal injection, the negative mold having a plurality of sections, at least one section having a negative mold of a group of substantially parallel heat transfer protuberances; and b. pulling apart the plurality of sections for releasing a cast part.
- 6. A method in accordance with claim 1, further comprising inserting longitudinal dividing structures between groups of substantially parallel heat transfer protuberances.
- 7. A method for fabricating heat transfer protuberances for conducting heat through a cylindrical wall between a fluid exterior to the wall and a working gas interior to the cylindrical wall, the method comprising:
a. integrally fabricating at least one backing panel including a segment of a cylinder and a group of substantially parallel heat transfer protuberances having axes normal to the cylindrical axis; and b. bonding the at least one backing panel to a structure in thermal contact with the cylindrical wall.
- 8. A method in accordance with claim 7, wherein the step of integrally fabricating the at least one backing panel includes casting the backing panel.
- 9. A method in accordance with claim 7, wherein the step of integrally fabricating the at least one backing panel includes injection molding the backing panel.
- 10. The method of claim 7, wherein the step of bonding includes mechanically attaching the panel to the heater head.
- 11. The method of claim 7, wherein the step of bonding includes brazing the panel of the array of heat transfer pins to the heater head.
- 12. The method of claim 7, wherein the step of bonding includes transient liquid-phase bonding of the panel of the array of heat transfer pins to the heater head.
- 13. A method in accordance with claim 7, further comprising inserting longitudinal dividing structures between groups of substantially parallel heat transfer protuberances.
- 14. A method for enhancing efficiency of thermal transfer through a heater head to a working gas in a thermal cycle engine, the heater head having an interior surface, the method comprising the step of applying one or more layers of high-thermal-conductivity metal to the at least one of the interior and exterior surfaces of the heater head.
- 15. In a heater head for a thermal cycle heat engine, the heater head having a substantially cylindrical wall section, an improvement comprising a plurality of ribs interior to the substantially cylindrical wall section for providing enhanced hoop strength.
- 16. In a heater head for a thermal cycle heat engine, the heater head having a substantially cylindrical wall section and a central longitudinal axis, an improvement comprising a plurality of passages within the substantially cylindrical wall section extending parallel to the central longitudinal axis.
- 17. In a heater head for a thermal cycle heat engine, the heater head having a substantially cylindrical wall section and a central longitudinal axis, an improvement comprising a plurality of ribs interior to the substantially cylindrical wall section for providing enhanced hoop strength and a plurality of passages substantially parallel to the central longitudinal axis and passing through the ribs.
- 18. In a heater head for a thermal cycle heat engine, the heater head having a substantially cylindrical wall section, an improvement comprising a substantially helical channel within the substantially cylindrical wall section.
- 19. In a heater head for a thermal cycle heat engine, the heater head having a dome, an improvement comprising a plurality of ribs interior to the dome for providing enhanced dome strength.
- 20. In the heater head of any of claims 15 through 19, the additional improvement of a plurality of flow diverters extending transversely from a hot sleeve disposed internally to, and concentrically with, the cylindrical wall section.
- 21. In a thermal cycle engine of the type having a piston undergoing reciprocating linear motion within an expansion cylinder, the expansion cylinder having a cylindrical wall and containing a working fluid heated by conduction through a heater head of heat from an external thermal source, the conduction characterized by a heat transfer coefficient, the improvement comprising:
a. a heat exchanger for transferring thermal energy across the heater head from a heated external fluid to the working fluid, the heat exchanger comprising a set of heat transfer protuberances, each heat transfer protuberance having an axis directed substantially away from the cylindrical wall of the expansion cylinder; and b. means for increasing the heat transfer coefficient in a direction of flow of the heated external fluid.
- 22. A heat exchanger for transferring thermal energy from a heated external fluid across a cylindrical wall, the cylindrical wall characterized by a length direction parallel to a central axis of the cylindrical wall, the heat exchanger comprising:
a. a set of staggered heat transfer protuberances, each heat transfer protuberance having an axis directed substantially away from the cylindrical wall; b. a plurality of dividers disposed substantially along the length of the cylindrical wall, for forcing fluid flow through the staggered heat transfer protuberances.
- 23. A heat exchanger for transferring thermal energy from a heated external fluid across a cylindrical wall characterized by an axial direction, the heat exchanger comprising:
a. a set of heat transfer protuberances, each heat transfer protuberance having an axis directed substantially away from the cylindrical wall; b. a backer for guiding the heated external fluid in a flow path substantially along the axial direction of the cylindrical wall past the set of heat transfer protuberances.
- 24. The heat exchanger of claim 18, wherein a gap between the backer and the cylindrical wall decreases in the axial direction.
- 25. The heat exchanger of claim 18, wherein the heat transfer protuberances have a surface area transverse to the flow path that increases in the axial direction.
- 26. The heat exchanger of claim 18, wherein the heat transfer pins have a population density that increases in the axial direction.
- 27. The heat exchanger of claim 18, wherein at least one of the height and density of the heat transfer pins varies with distance in the axial direction.
Parent Case Info
[0001] The present application is a continuation-in-part of U.S. application Ser. No. 09/517,245, filed Mar. 2, 2000, itself a continuation-in-part application of U.S. application Ser. No. 09/115,383, filed Jul. 14, 1998, and issued May 16, 2000 as U.S. Pat. No. 6,062,023, and a continuation-in-part also of Ser. No. 09/115,381, filed Jul. 14, 1998 and now abandoned, claiming priority from U.S. provisional application No. 60/052,535, filed Jul. 15, 1997, all of which applications are herein incorporated by reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60052535 |
Jul 1997 |
US |
Continuation in Parts (3)
|
Number |
Date |
Country |
Parent |
09517245 |
Mar 2000 |
US |
Child |
09884436 |
Jun 2001 |
US |
Parent |
09115383 |
Jul 1998 |
US |
Child |
09517245 |
Mar 2000 |
US |
Parent |
09115381 |
Jul 1998 |
US |
Child |
09115383 |
Jul 1998 |
US |