Aluminum Heat Exchange Tube and Process for Fabricating Same

• US 20080047683A1
• Filed: 06/28/2005
• Published: 02/28/2008
• Est. Priority Date: 06/28/2004
• Status: Abandoned Application

• Current Assignee: Showa Denko KK
• Original Assignee: Showa Denko KK
• Inventors: Takahashi, Kazuyuki
• Application Number:
  US11/571,361
• Publication Number:
  US 20080047683A1
• Time in Patent Office: Days
• US Class Current: 165/41
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: F25B 2309/061 with cycle highest pressure above the supercritical pressure
• CPC Class Codes: F28D 1/05383 with multiple rows of conduits or with multi-channel conduits F28D1/05391 takes precedence
• CPC Class Codes: F28D 2021/0084 Condensers
• CPC Class Codes: F28D 2021/0085 Evaporators
• CPC Class Codes: F28F 1/04 polygonal, e.g. rectangular F28F1/022 takes precedence
• CPC Class Codes: F28F 21/084 from aluminium or aluminium alloys
• CPC Class Codes: Y10T 29/4935 Heat exchanger or boiler making

Abstract

An aluminum heat exchange tube 4 is made of an alloy comprising 0.90 to 1.50 mass % of Mn, and the balance Al and inevitable impurities, and has electric conductivity of 30 to 43% IACS. The tube 4 is fabricated from a tube blank made of an alloy comprising 0.90 to 1.50 mass % of Mn, and the balance Al and inevitable impurities, by holding the blank heated at 550 to 600 C in the atmosphere or in an inert gas atmosphere for 10 to 600 minutes and subsequently cooling the blank. The tube is easy and inexpensive to make and satisfactory in resistance to pitting corrosion.

Claims

1. An aluminum heat exchange tube made of an alloy containing 0.90 to 1.50 mass % of Mn, the balance being Al and impurities, the tube having electric conductivity of 30 to 43% IACS.

2. An aluminum heat exchange tube according to claim 1 wherein the impurities include Cu, and the content of Cu is up to 0.05 mass %.

3. An aluminum heat exchange tube according to claim 1 wherein the impurities include Fe, and the content of Fe is up to 0.25 mass %.

4. An aluminum heat exchange tube according to claim 1 wherein the impurities include Si, and the content of Si is up to 0.25 mass %.

11. A heat exchanger comprising an aluminum heat exchange tube according to claim 1.

12. A refrigeration cycle which comprises a compressor, a capacitor and an evaporator and wherein a chlorofluorocarbon refrigerant is used, the condenser being a heat exchanger according to claim 11.

13. A vehicle having installed therein refrigeration cycle according to claim 12 as a motor vehicle air conditioner.

14. A supercritical refrigeration cycle which comprises a compressor, a gas cooler, an evaporator and an intermediate heat exchanger for subjecting a refrigerant flowing of the gas cooler and a refrigerant flowing out of the evaporator to heat exchange and wherein a supercritical refrigerant is used, the gas cooler comprising a heat exchanger according to claim 11.

15. A vehicle having installed therein a refrigeration cycle according to claim 14 as a motor vehicle air conditioner.

5. A process for fabricating an aluminum heat exchange tube wherein a tube blank made of an alloy comprising 0.90 to 1.50 mass % of Mn, and the balance Al and impurities is held heated at 550 to 600°

C. in the atmosphere or in an inert gas atmosphere for 10 to 600 minutes and subsequently cooled.

6. A process for fabricating an aluminum heat exchange tube according to claim 5 wherein the alloy making the tube blank contains Cu as included among the impurities, and the content of Cu is up to 0.05 mass %.

7. A process for fabricating an aluminum heat exchange tube according to claim 5 wherein the alloy making the tube blank contains Fe as included among the impurities, and the content of Fe is up to 0.25 mass %.

8. A process for fabricating an aluminum heat exchange tube according to claim 5 wherein the alloy making the tube blank contains Si as included among the impurities, and the content of Si is up to 0.25 mass %.

9. A process for fabricating an aluminum heat exchange tube according to claim 5 wherein the temperature is raised at a rate of 20 to 130°

C./min for heating the blank.

10. A process for fabricating an aluminum heat exchange tube according to claim 5 wherein the blank is cooled at a rate of at least 47°

C./min after the heating.