JPS59104285A - Production of heat transmitting pipe - Google Patents

Abstract

PURPOSE:To develop a heat transmitting pipe having a high heat transmission rate in the pipe by laminating fine particles of the same metal as a metallic plate material having excellent heat transmission on the surface of said metallic plate material, joining both materials by heating and pressing in a vacuum furnace then forming the laminate into a pipe shape with the fine metallic particle layer on the inside. CONSTITUTION:Pulverous powder 2 of Cu or Al is sprayed on a metallic plate 1 of likewise Cu or Al having excellent heat conductivity. Both materials are sandwiched and pressed by means of jigs 4 from above and below and are subjected to diffusion bonding in a vacuum furnace. The joined material is formed into a pipe shape with the layer 2 on the inside, and both ends 5 are joined by resistance welding, thereby manufacturing a heat transmitting pipe having a circular section. The inside surface of the heat transmitting pipe is porous and has many voids, which play the roll of fins and the heat transmitting pipe having a high heat transmission rate in the pipe is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a heat transfer tube suitable for use in a refrigerant evaporator.

In evaporators used in refrigerators and air conditioners, the heat transfer characteristics of the air flowing outside the heat transfer tubes have been improved. There is a growing need to improve the heat transfer coefficient on the side.

In order to improve the heat transfer inside the heat transfer tube heavy metal.

Conventionally, methods have been used to form inner diameter fins on the inner surface of a tube by extrusion processing, but even if the shape of the inner diameter fins is changed, there is a limit to the improvement in heat transfer coefficient.

In view of the above, the present invention seeks to provide a method for manufacturing a heat exchanger tube with a high intra-tube transfer coefficient.

The following description will be made based on an embodiment shown in the drawings.

First, as shown in Fig. 1, copper or aluminum powder 2 in the form of J:Kf fine particles of a copper or aluminum plate-like tube material 1 is sprinkled to a constant thickness using a pumper 3.

Next, the tube material 1 on which the powder 2 has been sprinkled in this manner is pressurized from above and below with a jig 4 as shown in FIG. 2, and is diffusion bonded (or sintered) in a vacuum furnace, as shown in FIG. The particles 2 are bonded to the upper surface of the tube material 1 in this way, and the particles 2 are also bonded together.

The long tube material 1 produced as described above is formed into a tube shape with the π fine particle layer inside as shown in FIG. They are joined by resistance welding to produce a heat exchanger tube with a circular cross section.

The average evaporative heat transfer coefficient within the tube of the evaporator using the heat transfer tube manufactured in this manner was increased by 20 to 30% compared to a smooth tube.

Specific Example ■ Copper particles having an average particle size of 60 mm/yu are uniformly scattered on a copper plate (material: DCupl) having a thickness of 07 mm and a width of 50 mm to a thickness of 0.15 mm.

■ Tighten the copper plate sprinkled with the above copper particles from above and below using a complete jig so that the average surface pressure is 0.5 kg/w112.

(2) The copper plate tightened with a jig is cooled in a vacuum furnace at 1 Torr at 500 to 600°C for 1 hour with nitrogen gas as a holding layer.

■ A long plate with copper particles fully sintered on a copper plate in the process described above is manufactured using electric resistance welded pipe manufacturing equipment using high-frequency induction heating to an outer diameter of approximately 8 zm 9! Form into a circular tube of J.

The cross-sectional void of the porous portion on the inner surface of the tube produced as described above was 30 to 50 mm wide.

[Brief explanation of drawings]

1 to 4 are explanatory diagrams for explaining one embodiment of the method of the present invention. Kan Sori 1. Fine particles...2゜

Claims (1)

[Claims] A first step in which fine particles such as copper or aluminum are scattered and laminated on the tube material, and a second step in which the fine particle layer is pressurized and heated in a vacuum furnace to be diffusion bonded or sintered to the tube material. A method for producing a heat exchanger tube, comprising a third step of electrically welding the tube material to form the tube so that the fine particle layer becomes the inner surface of the tube.