Heat engine system

Patent metadata

Field	Value
Publication number	US-10358945-B2
Application number	US-201615064730-A
Country	US
Kind code	B2
Filing date	Mar 9, 2016
Priority date	Dec 21, 2012
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

An improved heat engine includes at least one heat pipe containing a working fluid flowing in a thermal cycle between vapor phase at an evaporator end and liquid phase at a condenser end. The heat pipe may have an improved capillary structure configuration with a continuous or stepwise gradient in pore size along the capillary flow direction. The heat engine may have an improved generator assembly configuration that includes an expander (e.g. rotary/turbine or reciprocating piston machine) and generator along with magnetic bearings, magnetic couplings, and/or magnetic gearing. The expander-generator may be wholly or partially sealed within the heat pipe. A heat engine system (e.g. individual heat engine or array of heat engines in series and/or in parallel) for converting thermal energy to useful work (including heat engines operating from a common heat source) is also disclosed. The system can be installed in a vehicle or facility to generate electricity.

First claim

The invention claimed is:

1. A heat engine system comprising:
at least one heat engine comprising at least one heat pipe;
a generator assembly comprising an expander and a generator;
wherein the at least one heat pipe contains a working fluid and comprises an evaporator section and a condenser section;
wherein the at least one heat pipe has a capillary structure for the flow of working fluid in liquid phase from the condenser section to the evaporator section;
wherein the expander is installed within the at least one heat pipe;
wherein the expander is coupled to the generator by a coupling system that includes a magnetic coupling between the expander and the generator, the magnetic coupling including a first rotating member within the at least one heat pipe and a second rotating member outside the at least one heat pipe and magnetically coupled to the first rotating member; and
wherein the capillary structure comprises a first capillary region adjacent the evaporator section having a first feature size and a second capillary region adjacent the condenser section having a second feature size, wherein the first feature size is smaller than the second feature size and gradually changes from the first feature size to the second feature size.

2. The system of claim 1 wherein the generator assembly generates electrical power.

3. The system of claim 1 wherein the expander comprises a turbine system within the heat pipe.

4. The system of claim 3 wherein the turbine system comprises a multistage turbine within the heat pipe.

5. The system of claim 3 wherein the generator assembly is at least partially installed within the heat pipe.

6. The system of claim 1 further comprising a heat engine array with a first heat pipe and a second heat pipe.

7. The system of claim 6 wherein a shaft couples an expander within the first heat pipe to an expander within the second heat pipe.

8. The system of claim 1 wherein the generator assembly comprises a bearing system with bearings mounted on a rim for a shaftless rotor of the expander.

9. The system of claim 1 wherein the expander comprises a turbine system.

10. The system of claim 1 comprising a bearing system for the generator assembly.

11. The system of claim 1 wherein the capillary structure comprises a passage asymmetrically around an axial turbine system.

12. The system of claim 1 wherein the expander comprises multiple turbines within the heat pipe.

13. The system of claim 1 comprising a first passage within the heat pipe and a second passage external to the heat pipe for the working fluid in vapor phase.

14. The system of claim 1 wherein the heat engine system comprises a first evaporator section and a second evaporator section.

15. The system of claim 1 wherein the heat engine system comprises a first condenser section and a second condenser section.

16. The system of claim 1 wherein the heat engine system comprises a heat pipe with a chamber at the evaporator section and at the condenser section.

17. The system of claim 1 further comprising a common reservoir to provide flow return for the working fluid to the evaporator section of the at least one heat pipe.

18. The system of claim 17 further comprising a pump to increase a pressure differential of the working fluid supplied to the evaporator section.

19. The system of claim 1 wherein each heat engine comprises a first heat pipe with a first operating temperature range in thermal series with a second heat pipe with a second operating temperature range below the first operating temperature range.

20. The system of claim 19 wherein the first heat pipe comprises an expander-generator and the second heat pipe comprises an expander-generator.

21. The system of claim 20 wherein the first heat pipe and the second heat pipe are coupled by a shaft.

22. The system of claim 20 wherein a turbine system of the first heat pipe and a turbine system of the second heat pipe are coupled by a coupling.

23. The system of claim 22 wherein the coupling is a magnetic coupling.

24. The system of claim 22 wherein the coupling comprises a gear system.

25. The system of claim 22 wherein a rotor of the first expander and a rotor of the second expander share a common shaft.

26. The system of claim 1 wherein the generator assembly comprises multiple generators.

27. The system of claim 1 wherein the generator assembly comprises a magnetic gear system.

28. The system of claim 1 wherein the heat pipe comprises an internal rotary turbine.

29. The system of claim 28 wherein the internal rotary turbine comprises an integral tip magnet.

30. The system of claim 28 wherein the internal rotary turbine comprises a rotor and a stator with separate ring magnets.

31. The system of claim 30 wherein the stator comprises a stationary magnetic coupling structure.

32. The system of claim 30 wherein the rotor comprises a ring magnet system.

33. The system of claim 30 wherein the rotor comprises an armature.

34. The system of claim 30 wherein the rotor comprises a coil.

35. The system of claim 30 wherein the stator comprises a coil.

36. The system of claim 28 wherein the internal rotary turbine generates rotation at a shaft coupled to the generator and the generator generates AC current.

37. A heat engine system comprising:
at least one heat engine comprising at least one capillary-pumped heat pipe;
a generator assembly comprising an expander and a generator;
a magnetic coupling to couple the expander to the generator, the magnetic coupling including a first rotating member within the at least one heat pipe and a second rotating member outside the at least one heat pipe and magnetically coupled to the first rotating member;
wherein the at least one heat pipe contains a working fluid and comprises an evaporator section and a condenser section;
wherein the expander is installed within the at least one heat pipe between the evaporator section and the condenser section;
wherein the at least one heat pipe has a capillary structure with a first capillary region adjacent the evaporator section having a first feature size and a second capillary region adjacent the condenser section having a second feature size; and
wherein for at least one heat pipe the first feature size is smaller than the second feature size;
so that the capillary structure supports a pressure differential between the evaporator section and the condenser section to facilitate high-efficiency operation of the heat engine with the working fluid in vapor phase performing useful work through the expander.

Assignees

• Elwha Llc

Inventors

• Kare Jordin T
• Myhrvold Nathan P
• Petroski Robert C
• Wood Jr Lowell L

Classifications

• F01K13/00

  General layout or general methods of operation of complete plants · CPC title

• F28D15/04

  with tubes having a capillary structure · CPC title

• H02K7/1823

  structurally associated with turbines or similar engines · CPC title

• F01K25/12

  the vapours being metallic, e.g. mercury · CPC title

• F28D2015/0291

  comprising internal rotor means, e.g. turbine driven by the working fluid · CPC title