JPH0345034Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention consists of dividing the inside of a flat tube into a large number of passages by partition walls, and forming a flat tube by extrusion or pultrusion molding, in which inner fins are provided on the inner surface of each passage. This invention relates to improvement of passage type heat exchanger tubes.

(Prior art) Figure 1 shows a conventional flat multi-passage heat exchanger tube a.
As shown in the enlarged view of the passageway in Fig. 2, an inner fin b is machined on the inner circumferential surface of the passageway to form a square passageway d consisting of the inner fin b and a smooth part c, and the flow inside the multipassage heat exchanger tube a is formed. Efforts are being made to improve the heat transfer coefficient of refrigerants such as Freon.

(Problems to be solved by the invention) However, in the conventional flat multi-passage type heat exchanger tube, there is a limit to how thin the wall can be made in terms of pressure resistance because of the rectangular passages. It was difficult to form fins on the inner fins, and the number of inner fins was reduced, making it impossible to fully demonstrate the effect.

Furthermore, because the conventional heat transfer tube has a rectangular passage, the inner fins cannot be arranged at equal pitches. Therefore, in order to ensure that the refrigerant flowing between the inner fins has a uniform velocity, a moving force in the direction perpendicular to the flow direction, so-called double Secondary flow occurred, resulting in increased flow loss and problems in terms of heat transfer performance.

(Means for Solving the Problems) The present invention was proposed in order to eliminate such drawbacks.The inside of a flat tube is divided into a large number of passages by partition walls, and an inner fin is installed on the inner surface of each passage. In a flat passage-shaped heat exchanger tube formed by extrusion or pultrusion molding, each passage has a round cross-sectional shape, and inner fins are integrally molded around the entire inner circumference of each passage at approximately equal pitches. The present invention relates to a heat exchanger tube characterized by:

(Function) and (Effects of the invention) As described above in this invention, the cross-sectional shape of the passage in a flat multi-passage heat exchanger tube is changed from the conventional square shape to a round shape, and a large number of inner fins are arranged around the inner surface of the passage at approximately equal pitches. By arranging the passageway so that the refrigerant flows between the inner fins at a uniform speed, the heat transfer coefficient is improved, and since the passageway has a round cross section, it can be made thinner. Since the present invention has many advantages, it can be applied to heat exchanger tubes, heat exchangers, and air conditioners using these.

(Example) The present invention will be described below with reference to the illustrated embodiments.

In Fig. 3, reference numeral 1 denotes a passage in a flat multi-passage heat exchanger tube 2 formed by extrusion or pultrusion, in which the inside of the flat tube is divided by partition walls, and is formed with a round cross section and extends over the entire inner circumference of the tube. Inner fins 3 are arranged at even pitches.

According to the embodiment described above, since the passage 1 is formed to have a round cross section, there is no possibility that the inner fins cannot be arranged at equal pitches at the corner parts, unlike in the conventional square passage. , a large number of inner fins 3 can be arranged at approximately equal pitches.

Therefore, since the refrigerant such as Freon flowing through the passage 2 flows at a uniform speed between the inner fins 3, the heat transfer coefficient is improved, and since the passage 2 has a round cross section, the tube wall thickness t ₁ is acceptable in terms of pressure resistance. , t ₂ can be made thinner.

FIG. 4 shows another embodiment of the present invention, in which grooves 4 are formed on the outer surface of the flat multi-channel heat exchanger tube 2 between adjacent passages 1 and 1 having round cross sections, leaving at least a tube wall thickness t ₁ . processed and therefore suitable for eliminating dehumidified drain water from the air when applied to an evaporator.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional flat multi-channel heat exchanger tube, FIG. 2 is a partially enlarged view thereof, and FIGS. 3 and 4 are longitudinal sectional views showing respective embodiments of the heat exchanger tube according to the present invention. It is. 1... passage, 2... flat multi-passage type heat exchanger tube, 3...
…Innahuin.

Claims (1)

[Scope of utility model registration request] In a flat passage-shaped heat exchanger tube formed by extrusion or pultrusion, in which the inside of the flat tube is partitioned into a large number of passages by partition walls, and inner fins are provided on the inner surface of each passage, each passage has a round cross-sectional shape. In addition, a heat exchanger tube characterized in that inner fins are integrally molded at approximately equal pitches around the inner surface of each passage.