Two-phase heat transfer device

• US 10,209,008 B2
• Filed: 05/28/2014
• Issued: 02/19/2019
• Est. Priority Date: 05/29/2013
• Status: Active Grant

• Current Assignee: Euro Heat Pipes SA
• Original Assignee: Euro Heat Pipes SA
• Inventors: Dupont, Vincent
• Primary Examiner(s): Raymond, Keith M
• Assistant Examiner(s): Diaz, Miguel A
• Application Number:
  US14/893,877
• Publication Number:
  US 20160116226A1
• Time in Patent Office: 1,728 Days
• Field of Search: 16510421, 16510422, 16510424, 220578, 220216, 220218, 220734
• CPC Class Codes: B60H 1/00492 comprising regenerative heating or cooling means, e.g. heat accumulators
• CPC Class Codes: B60H 1/3202 using evaporation, i.e. not including a compressor, e.g. involving fuel or water evaporation B60H1/3235 takes precedence; in general F25B19/00, F25D7/00
• CPC Class Codes: F25B 23/00 Machines, plants or systems, with a single mode of operation not covered by groups F25B1/00 - F25B21/00, e.g. using selective radiation effect
• CPC Class Codes: F25B 23/006 boiling cooling systems
• CPC Class Codes: F28D 15/025 having non-capillary condensate return means
• CPC Class Codes: F28D 15/043 forming loops, e.g. capillary pumped loops
• CPC Class Codes: F28F 2265/12 for preventing overpressure

Abstract

A two-phase heat transfer device that is capillary-driven or gravity-driven, has a two-phase working fluid contained in a closed general circuit, including an evaporator, a condenser, a reservoir having an inner volume with a liquid portion and a gas portion, a first vapor communication circuit, and a second liquid phase communication circuit. The reservoir comprises a plurality of floating bodies separating the liquid portion from the gas portion, by means of which the heat exchanges between the liquid portion and the gas portion are slowed down, which allows to diminish the effect of movement of the liquid portion or of an influx of cold or warm liquid into the reservoir.

Claims

1. A heat transfer device, subject to gravity, suitable for extracting heat from a heat source and for restoring this heat to a cold source by a two-phase working fluid contained in a closed general circuit, comprising:

at least one evaporator, having an inlet and an outlet,

at least one condenser,

a reservoir having an inner volume filled with a working fluid in two-phase form with a liquid portion and a gas portion separated by a liquid-gas interface, and at least one inlet and/or outlet port, the reservoir serving as an expansion tank for the working fluid,

a first communication circuit, for fluid mainly in the vapor phase, connecting the outlet of the evaporator to an inlet of the condenser,

a second communication circuit, for fluid mainly in the liquid phase, connecting an outlet of the condenser to the reservoir and to the inlet of the evaporator, wherein;

the reservoir comprises a plurality of floating bodies separating the liquid portion from the gas portion and forming a thermal barrier, by means of which heat exchanges between the liquid portion and the gas portion are slowed down, while allowing liquid-gas exchanges at the liquid-vapor interface at saturation conditions,

said floating bodies are enveloped in a net,

said plurality of floating bodies forms a plurality of superimposed layers, and

the net allows the floating bodies, whenever the reservoir is tilted, to reconfigure themselves spatially to occupy in a permeable manner all of the surface of the liquid-gas interface.

2. The heat transfer device according to claim 1, wherein all of said floating bodies have substantially the same shape.

3. The heat transfer device according to claim 1, wherein said floating bodies include a material chosen among stainless steel, polytetrafluorethylene, borosilicate, carbon, ceramics.

4. The heat transfer device according to claim 1, wherein said floating bodies have a spherical shape with a diameter that is between 0.5 and 10 mm.

5. The heat transfer device according to claim 1, wherein a volume occupied by the plurality of said floating bodies is between 3% and 12% of a total volume of the reservoir.

6. The heat transfer device according to claim 1, wherein the reservoir comprises an input stream deflector near the inlet port.

7. The heat transfer device according to claim 1, wherein the evaporator comprises a microporous mass suitable for performing the capillary pumping of fluid in the liquid phase.

8. The heat transfer device according claim 1, wherein the evaporator is placed below the condenser and the reservoir, so that gravity is used to move the liquid towards the evaporator.

19. The heat transfer device according to claim 1, wherein the net is attached to an internal side wall of the reservoir.

20. The heat transfer device according to claim 1, wherein the reservoir includes a top wall enclosing a top of the reservoir.

9. A heat transfer device, mainly subject to gravity, suitable for extracting heat from a heat source and for restoring this heat to a cold source by means of a two-phase working fluid contained in a closed general circuit, comprising:

at least one evaporator, having an inlet and an outlet,

at least one condenser,

a reservoir having an inner volume filled with a working fluid in two-phase form with a liquid portion and a gas portion separated by a liquid-gas interface, and at least one inlet and/or outlet port, the reservoir serving as expansion tank for the working fluid,

a first communication circuit, for fluid mainly in the vapor phase, connecting the outlet of the evaporator to an inlet of the condenser,

a second communication circuit, for fluid mainly in the liquid phase, connecting an outlet of the condenser to the reservoir and to the inlet of the evaporator, wherein;

the reservoir comprises a plurality of floating bodies separating the liquid portion from the gas portion and forming a thermal barrier, by means of which the heat exchanges between the liquid portion and the gas portion are slowed down, while allowing liquid-gas exchanges at the liquid-vapor interface at saturation conditions,

the reservoir comprises a lower grid and an upper grid, arranged respectively away from a bottom wall and away from a top wall of the reservoir, so that these two grids prevent the floating bodies from crossing them,

said plurality of floating bodies forms a plurality of superimposed layers, and

the floating bodies, whenever the reservoir is tilted, reconfigure themselves spatially to occupy in a permeable manner all of the surface of the liquid-gas interface.

10. The heat transfer device according to claim 9, wherein all of said floating bodies have substantially the same shape.

11. The heat transfer device according to claim 9, wherein said floating bodies are made of a material chosen among a group comprising stainless steel, polytetrafluoroethylene, borosilicate, carbon, ceramics.

12. The heat transfer device according to claim 9, wherein said floating bodies have a spherical shape, with a diameter that is between 0.5 and 10 mm.

13. The heat transfer device according to claim 9, wherein the volume occupied by the plurality of said floating bodies is between 3% and 12% of the total volume of the reservoir.

14. The heat transfer device according to claim 9, wherein the reservoir comprises an input stream deflector near the inlet port.

15. The heat transfer device according to claim 9, wherein the evaporator comprises a microporous mass suitable for performing the capillary pumping of fluid in the liquid phase.

16. The heat transfer device according to claim 9, mainly subject to gravity, wherein the evaporator is placed below the condenser and the reservoir, so that gravity is used to move the liquid towards the evaporator.

17. The heat transfer device according to claim 9, wherein the at least one inlet and/or outlet port includes an inlet port and an outlet port that are both located at the bottom wall of the reservoir.

18. The heat transfer device according to claim 9, wherein the upper grid is positioned above the liquid portion in the reservoir.