HEAT TRANSFER CONTROLLING MECHANISM AND FUEL CELL SYSTEM HAVING THE HEAT TRANSFER CONTROLLING MECHANISM

• US 20100221627A1
• Filed: 10/24/2007
• Published: 09/02/2010
• Est. Priority Date: 10/27/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nakakubo, Toru
• Granted Patent: US 8,020,613 B2
• Time in Patent Office: Days
• US Class Current: 429/434
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence
• CPC Class Codes: F28D 15/043 forming loops, e.g. capillary pumped loops
• CPC Class Codes: F28D 15/06 Control arrangements therefor
• CPC Class Codes: F28F 2245/02 hydrophilic
• CPC Class Codes: F28F 2245/04 hydrophobic
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04074 Heat exchange unit structures specially adapted for fuel cell
• CPC Class Codes: H01M 8/04208 Cartridges, cryogenic media or cryogenic reservoirs
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A heat transfer controlling mechanism and a fuel cell system, which allow working fluid to flow in a predetermined direction in a loop-shaped flow path without a back flow, having a simple structure independent of the orientation during use, low power consumption, and efficient heat transfer and size reduction. The mechanism includes a vaporizing portion, a condensing portion, and a loop-shaped flow path connecting the vaporizing and the condensing portions so as to seal working fluid. The mechanism transports heat by vaporizing the fluid in the vaporizing portion and condensing the fluid in the condensing portion to control heat transfer. The mechanism further includes a gas passage suppressing portion on one side in the flow path, for allowing liquid, but not gas, to pass therethrough and a liquid passage suppressing portion on the other side in the flow path, for allowing gas, but not liquid, to pass therethrough.

Claims

1. A heat transfer controlling mechanism comprising a vaporizing portion;

a condensing portion; and

a loop-shaped flow path connecting the vaporizing portion and the condensing portion such that a working fluid is sealed therein,

the heat transfer controlling mechanism serving to perform heat transport by an action of vaporization of the working fluid in the vaporizing portion and by an action of condensation of the working fluid in the condensing portion to thereby control heat transfer,

the heat transfer controlling mechanism further comprising;

a gas passage suppressing portion provided on one side in the loop-shaped flow path, for allowing a liquid to pass therethrough and suppressing passage of a gas; and

a liquid passage suppressing portion provided on the other side in the loop-shaped flow path, for allowing a gas to pass therethrough and suppressing passage of a liquid.

2. The heat transfer controlling mechanism according to claim 1, wherein the gas passage suppressing portion is formed of a member having hydrophilicity provided in a surface of the flow path.

3. The heat transfer controlling mechanism according to claim 1, wherein the liquid passage suppressing portion is formed of a member having hydrophobicity provided in a surface of the flow path.

4. The heat transfer controlling mechanism according to claim 1, wherein at least one of the gas passage suppressing portion and the liquid passage suppressing portion comprises a wettability changing portion comprising a material whose contact angle is changed at a predetermined temperature.

5. The heat transfer controlling mechanism according to claim 4, wherein the wettability changing portion comprises a material whose property changes from hydrophilicity to hydrophobicity at a predetermined temperature or more.

6. The heat transfer controlling mechanism according to claim 1, comprising a heat transfer controlling member adjacent to at least one of the vaporizing portion and the condensing portion, for changing an amount of heat transport by the actions of vaporization and condensation of the working fluid depending on a temperature state of the vaporizing portion or the condensing portion.

7. The heat transfer controlling mechanism according to claim 6, wherein the heat transfer controlling member is provided adjacent to the vaporizing portion or the condensing portion and changes a flow path resistance of the loop-shaped flow path depending on a temperature of the vaporizing portion or the condensing portion.

8. The heat transfer controlling mechanism according to claim 6, wherein the heat transfer controlling member is formed of a bimetal or a shape memory alloy.

9. The heat transfer controlling mechanism according to claim 6, wherein the heat transfer controlling member is formed of a material which undergoes phase transition depending on temperature to change the volume thereof.

10. A fuel cell system comprising:

a fuel tank;

a fuel cell unit for performing power generation using a fuel supplied from the fuel tank; and

the heat transfer controlling mechanism according to claim 1 provided between the fuel tank and the fuel cell unit,

wherein the condensing portion is disposed on the fuel tank side and the vaporizing portion is disposed on the fuel cell unit side.

11. A fuel cell system comprising:

a fuel tank;

a fuel cell unit for performing power generation using a fuel supplied from the fuel tank; and

the heat transfer controlling mechanism according to claim 1 provided between the fuel tank and the fuel cell unit,

wherein the fuel cell unit and a radiating plate having an air hole for supplying air are connected through a wettability changing portion whose contact angle changes at a predetermined temperature or through a heat transfer member having a thermal junction which operates at a predetermined temperature or more, and wherein the thermal junction includes a heat transfer controlling member in the heat transfer controlling mechanism.

12. The fuel cell system according to claim 11, further comprising a water flow path for guiding water produced by power generation in the fuel cell unit to the radiating plate.

13. The fuel cell system according to claim 12, wherein a pattern comprising a hydrophilic portion and a hydrophobic portion is formed on a surface of the water flow path.

14. The fuel cell system according to claim 11, wherein a water absorbing member is provided on a surface of the radiating plate.

15. The fuel cell system according to claim 14, wherein the water absorbing member comprises a member whose air permeation rate increases with increase of absorbed water amount.

16. A fuel cell system comprising a heat spreader for uniformizing a variance of heat produced by power generation in a fuel cell unit, wherein the heat spreader comprises the heat transfer controlling mechanism according to claim 1.

17. The fuel cell system according to claim 16, wherein the heat spreader also serves as at least one of the heat transfer controlling mechanism provided between the fuel cell unit and the fuel tank according to claim 10 and the radiating plate according to claim 11.