US20090056912A1

US20090056912A1 - Thermal device for heat exchange

Info

Publication number: US20090056912A1
Application number: US12/200,354
Authority: US
Inventors: Tom Kerber
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-08-29
Filing date: 2008-08-28
Publication date: 2009-03-05

Abstract

A thermal device for heat exchange between a substance in solid state and a substance in liquid state comprising a housing formed by two heat conducting plates disposed in parallel wherein wire-made grid-like 3-dimensional bracing is disposed between said plates and adapted to provide turbulent flow of said substance in liquid state; wires of said bracing are mechanically connected together and to said plates. A thermal device for heat exchange between a substance in solid state and a substance in gaseous state. A heat pipe container having a working fluid enclosed therein, said container formed by two heat conducting plates disposed in parallel against each other and sealed along their perimeter; said container having a capillary microchannel system for reversible fluid-gas circulation, wherein said capillary microchannel system is formed by wire-made grid-like 3-dimensional bracing disposed between said plates; wires of said bracing are mechanically connected together and to said plates.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is a non-provisional patent application claiming benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/935,736, filed Aug. 29, 2007, the entire contents of which are hereby expressly incorporated by reference into this disclosure as if set forth fully herein.

FIELD OF THE INVENTION

The present invention pertains generally to heating and/or cooling thermal devices and refers more particularly to compact plate-shaped heat devices.

BACKGROUND OF THE INVENTION

Delivering heat to any physical body by means of fluid or gaseous thermal transfer agents or extracting heat from this body in the same way is implemented by a thermal transfer device. This device is adapted to bring about a thermal contact between a heated/cooled body and a thermal transfer agent. Commonly this device is made of heat conducting metal. The effectiveness of the heat transfer depends on many variables including type and thickness of the metal, surface conditions on sides, heat transfer agent velocity and temperatures on both sides.
For efficiency, thermal devices are designed to maximize the surface area of thermal contact between the two bodies, while minimizing resistance to fluid flow through the device. The device's performance can also be affected by the addition of fins or corrugations that increases surface area and may and induce flow turbulence. U.S. Pat. Nos. 4,131,159, 4,854,382, 5,487,424 disclose a plate-type heat exchanger core comprising pleat-folded metal sheets. These patent specifications teach formed fins providing turbulence of heat transfer agent for more efficient heat exchange.
US Patent Application 2007/0144711A1 describes a heat exchanger plate comprising a number of turbulence-promoting protuberances having surface profiles effective in breaking up layers of laminar flow.
A common feature of these technical solutions is heat exchange occurring by means of thermal contact of the thermal transfer agent with the metal plates. Higher heat transfer efficiency can be achieved by means of increasing the number of metal plates used. However, metal fins disposed at shorter distance from each other increase flow resistance of the thermal device. A technical solution that increases thermal contact area and turbulent flow thermal exchange, but does not increase flow resistance is hence a long felt need.

SUMMARY OF THE INVENTION

It is hence one object of the invention to disclose a thermal device for heat exchange between a solid substance in solid state and a substance in liquid state comprising a housing formed by two heat conducting plates disposed in parallel against each other and sealed along their perimeter. At least one of the plates is thermally contacted with the substance in solid state. The housing has an input and an output ports for inflowing and outflowing the substance in liquid state. It is a core purpose of the invention wherein a wire-made grid-like 3-dimensional bracing is disposed between the plates and adapted to provide turbulent flow of the substance in liquid state. The wires of the bracing are mechanically connected together and to the plates.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above made of copper.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above made of aluminum.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above made of tin plated steel.
Another object of the invention is to disclose plates mechanically connected by soldering.
Another object of the invention is to disclose plates mechanically connected by welding.
A further object of the invention is to disclose a thermal device for heat exchange between a substance in solid state and a substance in gaseous state comprising a housing formed by two heat conducting plates disposed in parallel against each other and sealed along their perimeter. At least one plate is in thermal contact with the substance in solid state. The housing has input and an output ports for inflowing and outflowing the substance in gaseous state. It is a core purpose of the invention wherein a wire-made grid-like 3-dimensional bracing is disposed between the plates and adapted to provide turbulent flow of the substance in gaseous state. The wires of the bracing are mechanically connected together and to the plates.
A further object of the invention is to disclose a heat exchanger device for heat exchange between two heat transfer agents comprising two thermal devices. It is in the core of the invention wherein said thermal devices are thermally contacted with each other.
A yet further object of the invention is to disclose heat transfer agents, in both the thermal devices, in fluid state.
A still further object of the invention is to disclose heat transfer agents, in both the thermal devices, in gaseous state.
Lastly, a further object of the invention is to disclose heat exchange carried out between said heat transfer agents in fluid and gaseous states.
A further object of the invention is to disclose a heat pipe container having a working fluid enclosed therein. The container is formed by two heat conducting plates disposed in parallel against each other and sealed along their perimeter. The container has a capillary microchannel system for reversible fluid-gas circulation. It is a core purpose of the invention wherein the capillary microchannel system is formed by wire-made grid-like 3-dimensional bracing disposed between said plates. Wires of the bracing are mechanically connected together and to the plates.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above made of copper.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above made of aluminum.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above made of tin plated steel.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above are mechanically connected by soldering.
Another object of the invention is to disclose plates and wire-made grid-like 3-dimensional bracing as defined above are mechanically connected by welding.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be implemented in practice, a plurality of embodiments is adapted to now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which

FIG. 1 is a general isometric view of the thermal device;

FIG. 2 is an exploded isometric view of the thermal device;

FIG. 3 is a schematic isometric view of the exemplary wire arrangement;

FIG. 4 is a general isometric view of the heat exchanger; and

FIG. 5 is an exploded isometric view of the heat pipe.

DETAILED DESCRIPTION OF THE INVENTION

The following description is provided, alongside all chapters of the present invention, so as to enable any person skilled in the art to make use of said invention and sets forth the best modes contemplated by the inventor of carrying out this invention. Various modifications, however, is adapted to remain apparent to those skilled in the art, since the generic principles of the present invention have been defined specifically to provide a thermal device for heat exchange between a substance in solid state and a substance in liquid or gaseous state.
Reference is now made to FIG. 1, in accordance with the invention a thermal device 10 for heat exchange between a substance in solid state and a substance in liquid or gaseous state comprises a housing 12 having inlet and outlet ports 14 and 16, respectively, for inflowing and outflowing a heat transfer agent.
Reference is now made to FIG. 2, the housing 12 is formed by two heat conducting plates 20 disposed at a definite distance in parallel against each other and sealed along the housing perimeter by side and front battens 30 and 32, respectively. A wire-made grid-like 3-dimensional bracing 22 is located in the space between the heat conducting plates 20. Wires forming the bracing 22 are soldered or welded against each other and to the plates 20.
Reference is now made to FIG. 3 shows an exemplary wire arrangement 22 consisting of wires 24. The wires form a rigid structure providing a sufficient space for flowing of the thermal transfer agent and for thermal contact to be achieved between the wires and the heat conducting plates. The arrangement can have an ordered or chaotic structure. For example, the wires 24 can be shaped into a wave-like interwoven form. Extreme points 26 of the wires 24 are mechanically fixated (e.g. soldered or welded) on the internal surface of the heat conducting plates 20. The wires 24 are coupled in the same way together at points 28, as well.
Reference is now made to FIG. 4, a heat exchanger 50 comprising two heat devices 10 a and 10 b formed by three heat conducting plates 20 with wire-made grid-like 3-dimensional bracing 22 between them (not shown). The heat devices 10 a and 10 b are furnished by inlet and outlet ports 14 a, 14 b, 16 a, and 16 b, respectively. Heat exchange occurs through the heat conducting plate 12 located inside of the heat exchanger 50.
Reference is now made to FIG. 5, a heat pipe-like device embodies a container 60 formed by two heat conducting plates 20 disposed at a definite distance in parallel against each other and sealed along the housing perimeter by side and front battens 30 and 32, respectively. The distance between the heat conducting plates 20 is adapted to provide capillary conditions for an enclosed fluid. A wire-made grid-like 3-dimensional bracing 22 is located in the space between the heat conducting plates 20. Wires forming the bracing 22 are soldered or welded against each other and to the plates 20.
Velocity of heat transfer depends on the area of thermal contact and the degree of turbulence of the heat transfer agent flow. Incorporating the wire bracing 22 into the space between the heat conducting plates 20 increases both the area of thermal contact and the turbulence. Additionally, flow resistance is enhanced to a small extent. Such a thermal device 10 can effectively heat or cool any solid body due to heat conduction.
In accordance with one embodiment of the invention the heat transfer agent inflows through inlet port 14, comes in thermal contact with turbulence inducing wire-made bracing 22 and the heat conducting plates 12. Efficiency of heat transfer is increased in comparison with prior art due to the higher turbulence inducing capability of the wire-made bracing 22 and the possibility of incorporating large number of wires 24 without significantly increasing flow resistance. The heat transfer agent outflows from the thermal device 10 through outlet port 16.
According to different embodiments of the invention, the heat conducting plates 12 and the wire-made bracing 22 are made of copper, aluminum, tin plated steel or other heat conductive materials.
It should be noted that the wire-made bracing 22 is a continuous strength reinforcing framework element for internal high pressure conditions.
According to further different embodiments of the invention the heat transfer agent is selected from the group consisting of liquid agents like water, antifreeze, mineral, silicon, transformer, and fluorocarbon oils, refrigerants (Freons™ and others) and gaseous agents like air, inert gases, nitrogen, carbon dioxide, sulfur hexafluoride, or other heat transfer agents.
According to a further different embodiment of the invention which is non limiting and offered as an example, a pair of the thermal devices 10 being in thermal contact can be used as a heat exchanger 50 between fluid and gaseous heat transfer agents. As shown in the FIG. 4, fluid or gaseous agents are delivered into the thermal devices 10 a and 10 b through inlet ports 14 a and 14 b, respectively. Heat is transferred from the hotter agent to the cooler one. On the supposition that the hotter agent flows through the thermal device 10 a, the hotter agent transfers heat to the heat conducting plate. Further heat is transferred to the heat conducting plate and is extracted by the cooler agent. It is worthy of note that the efficiency of heat transfer is enhanced in both liquid and gaseous media.
According to a further different embodiment of the invention sandwich-type device is used as a heat pipe. In this case there is no heat transfer agent flowing through the device. The container 60 is completely sealed.
Heat pipes employ evaporative cooling to transfer thermal energy from one point to another by the evaporation and condensation of a working fluid or coolant. When one end of the heat pipe is heated the working fluid inside the pipe at that end evaporates and increases the vapor pressure inside the cavity of the heat pipe. The latent heat of evaporation absorbed by the vaporization of the working fluid reduces the temperature at the hot end of the pipe.
The vapor pressure over the hot liquid working fluid at the hot end of the pipe is higher than the equilibrium vapor pressure over condensing working fluid at the cooler end of the pipe, and this pressure difference drives a rapid mass transfer to the condensing end where the excess vapor condenses, releases its latent heat, and warms the cool end of the pipe.
The condensed working fluid then flows back to the hot end of the pipe. In the case of vertically-oriented heat pipes the fluid may be moved by the force of gravity. In the case of heat pipes containing wicks, the fluid is returned by capillary action.
Thus, incorporation of the wire-made bracing 22 into the space between two heat conducting plates 20 increases the area of thermal contact. This technical solution enables efficiency enhancement of heat transfer both heat exchanger 50 and heat pipe 60. The proposed devices can be used as effective heaters, coolers, thermal isolating screens, heat exchangers and for other purposes.

Claims

1. A thermal device for heat exchange between a substance in solid state and a substance in liquid state comprising a housing formed by two heat conducting plates disposed in parallel against each other and sealed along their perimeter, at least one said plate is thermally contacted with said substance in solid state; said housing has an input and an output ports for inflowing and outflowing said substance in liquid state; wherein wire-made grid-like 3-dimensional bracing is disposed between said plates and adapted to provide turbulent flow of said substance in liquid state; wires of said bracing are mechanically connected together and to said plates.

2. A thermal device for heat exchange according claim 1, wherein said plates and wires are made of copper.

3. A thermal device for heat exchange according claim 1, wherein said plates and wires are made of aluminum.

4. A thermal device for heat exchange according claim 1, wherein said plates are made of tin plated steel.

5. A thermal device for heat exchange according claim 1, wherein said wires and said plates are mechanically connected by soldering.

6. A thermal device for heat exchange according claim 1, wherein said wires and said plates are mechanically connected by welding.

7. A thermal device for heat exchange between a substance in solid state and a substance in gaseous state comprising a housing formed by two heat conducting plates disposed in parallel against each other and pressurized along their perimeter, at least one said plate is thermally contacted with said substance in solid state; said housing has an input and an output ports for inflowing and outflowing said substance in gaseous state; wherein wire-made grid-like 3-dimensional bracing is disposed between said plates and adapted to provide turbulent flow of said substance in liquid state; wires of said bracing are mechanically connected together and to said plates.

8. A thermal device for heat exchange according claim 7, wherein said plates and wires are made of copper.

9. A thermal device for heat exchange according claim 7, wherein said plates and wires are made of aluminum.

10. A thermal device for heat exchange according claim 7, wherein said plates are made of tin plated steel.

11. A thermal device for heat exchange according claim 7, wherein said wires and said plates are mechanically connected by soldering.

12. A thermal device for heat exchange according claim 7, wherein said wires and said plates are mechanically connected by welding.

13. A heat exchanger device for heat exchange between two heat transfer agents comprising two said thermal devices wherein said thermal devices are thermally contacted with each other.

14. A heat exchanger device for heat exchange according to claim 13 wherein said heat transfer agents in both said thermal devices are in fluid state.

15. A heat exchanger device for heat exchange according to claim 13 wherein said heat transfer agents in both said thermal devices are in gaseous state.

16. A heat exchanger device for heat exchange according to claim 13 wherein heat exchange is carried out between said heat transfer agents in fluid and gaseous states.

17. A heat pipe container having a working fluid enclosed therein, said container formed by two heat conducting plates disposed in parallel against each other and sealed along their perimeter; said container having a capillary microchannel system for reversible fluid-gas circulation, wherein said capillary microchannel system is formed by wire-made grid-like 3-dimensional bracing disposed between said plates; wires of said bracing are mechanically connected together and to said plates.

18. A heat pipe container according claim 17, wherein said plates and wires are made of copper.

19. A heat pipe container according claim 17, wherein said plates and wires are made of aluminum.

20. A heat pipe container according claim 17, wherein said plates are made of tin plated steel.

21. A heat pipe container according claim 17, wherein said wires and said plates are mechanically connected by soldering.

22. A heat pipe container according claim 17, wherein said wires and said plates are mechanically connected by welding.