CN-115053107-B - Inner spiral groove pipe and heat exchanger having excellent heat transfer property

CN115053107BCN 115053107 BCN115053107 BCN 115053107BCN-115053107-B

Abstract

The inner spiral groove tube of the present invention comprises a tube main body, a plurality of grooves and a plurality of fins arranged in an inner circumferential direction of the tube main body, wherein the plurality of grooves and the plurality of fins are formed in a spiral shape in a longitudinal direction of the tube main body, an outer diameter of the tube main body is 3mm or more and 10mm or less, the number of the fins formed on an inner circumferential surface of the tube main body is 30 to 60, the inner spiral groove tube is made of a metal, a cross-sectional shape of each of the fins in a cross section of the tube main body is a rectangle having a tip angle of 0.+ -. 10 degrees, a ratio h/f is 0.90 or more and 3.40 or less, h is a fin height, f is a fin width, a ratio c/f is 0.50 or more and 3.80 or less, c is a fin pitch between fins adjacent in the inner circumferential direction of the tube main body, and an average value obtained by summing the ratio h/f and the ratio c/f and dividing the sum by two is 0.8 or more and 3.3 or less.

Inventors

Toshihiro Harada
MASAYUKI NAKAMOTO
Ogawa Tuomi
NAKAURA SUKENORI

Assignees

MA铝株式会社

Dates

Publication Date: 20260508
Application Date: 20201127
Priority Date: 20191129

Claims (4)

1. An inner spiral groove tube comprising a tube main body, a plurality of grooves and a plurality of fins arranged in the inner circumferential direction of the tube main body, characterized in that, The plurality of grooves and the plurality of fins are formed in a spiral shape along a longitudinal direction of the tube main body, The outer diameter of the pipe body is 3mm to 10mm, The number of the fins formed on the inner peripheral surface of the tube main body is 30 to 60, The aforementioned inner helical grooved tube is made of metal, The cross-sectional shape of each of the aforementioned fins in the cross-section of the aforementioned tube main body is a rectangle having a tip angle of 0 + 2.5 degrees, The ratio h/f is more than 1.75 and less than 3.161, h is the fin height, f is the fin width, A ratio c/f of 1.547 to 2.965, c being a fin pitch between fins adjacent in the inner circumferential direction of the tube main body, And an average value obtained by summing the ratio h/f and the ratio c/f and dividing the sum by two is 2.4 or more and 2.6 or less, The rectangle having the vertex angle of 0 + 2.5 degrees means, The fin includes an isosceles trapezoid shape in which each side wall portion is inclined to 0 to +2.5 ゚ so that the side wall portions are slightly narrowed above each other, and an inverted isosceles trapezoid shape in which each side wall portion is inclined at an angle of-2.5 ゚ lower than 0 ° so that the side wall portions are slightly widened above each other, with respect to a vertex angle of 0 ° when the side wall portions are completely parallel to each other.
2. The inner helical groove pipe according to claim 1, wherein, The plurality of fins are arranged at equal intervals in the inner circumferential direction of the tube main body.
3. The inner helical groove pipe according to claim 1 or 2, wherein, The pipe body is made of aluminum or an aluminum alloy.
4. A heat exchanger, characterized in that, An inner helical groove pipe according to any one of claims 1 to 3.

Description

Inner spiral groove pipe and heat exchanger having excellent heat transfer property Technical Field The present invention relates to an inner spiral groove tube and a heat exchanger excellent in heat transfer property. The present application claims priority based on japanese patent application publication No. 2019-217440, 11-29 of 2019, the contents of which are incorporated herein by reference. Background Conventionally, a heat transfer tube of a fin tube type heat exchanger has been used, but a heat transfer tube of an aluminum alloy having light weight, low cost and excellent recyclability has been used because of exhaustion of copper resources, an increase in copper ingot price, and recyclability. Among heat transfer tubes using copper alloy or aluminum alloy, a heat transfer tube having spiral grooves on the inner surface thereof has been proposed in order to improve the thermal characteristics thereof. By spiraling the grooves on the inner surface, the area of the inner circumference of the tube is increased, and the wettability is improved by capillary phenomenon, whereby the refrigerant is rolled up, and the circumference length contributing to heat transfer can be increased. As a method for manufacturing an inner spiral groove pipe, a groove rolling method is known in which a groove plug supported by a connecting rod is disposed inside a pipe body, a rolling ball is rotatably disposed on an outer surface side of the pipe body in a circumferential direction, and the pipe body is pulled out while pressing an outer peripheral wall of the pipe body by the rolling ball, thereby performing groove processing (see patent document 1). However, when an inner spiral groove pipe having a small diameter is manufactured by the groove rolling method, it is difficult to adjust the shape of the spiral groove, and therefore, a technique has been proposed in which a drawing process and a twisting process are simultaneously performed on a drawn pipe having a linear groove provided on the inner surface thereof to form an inner spiral groove having an adjusted shape (see patent document 2). Further, by a method in which drawing and twisting are performed simultaneously, it is possible to manufacture an inner spiral groove tube having a groove shape with a groove opening smaller than the groove bottom width, that is, a spiral fin with an inverted trapezoidal cross section, which cannot be manufactured by the groove rolling method (see patent document 3). Patent document 1 Japanese patent laid-open No. 6-190476. Patent document 2 Japanese patent publication No. 6391140. Patent document 3 Japanese patent application laid-open No. 2018-091610. As described above, various improvements have been made in the manufacturing technology of the inner spiral groove pipe made of aluminum alloy, but in recent years, further improvement in the heat transfer characteristics of the inner spiral groove pipe has been demanded due to the response to environmental influences and the like. Disclosure of Invention The object of the present invention is to provide an inner helical groove tube with better heat transfer properties. The inner helical groove tube of the present invention comprises a tube main body, a plurality of grooves and a plurality of fins arranged in an inner circumferential direction of the tube main body, wherein the plurality of grooves and the plurality of fins are formed in a helical shape in a longitudinal direction of the tube main body, an outer diameter of the tube main body is 3mm or more and 10mm or less, the number of the fins formed on an inner circumferential surface of the tube main body is 30 to 60, the inner helical groove tube is made of a metal, a cross-sectional shape of each of the fins in a cross section of the tube main body is a rectangle having a tip angle of 0.+ -. 10 degrees, a ratio h/f is 0.90 or more and 3.40 or less, h is a fin height, f is a fin width, a ratio c/f is 0.50 or more and 3.80 or less, c is a fin pitch between fins adjacent in the inner circumferential direction of the tube main body, and an average value obtained by summing the ratio h/f and the ratio c/f and dividing the sum by two is 0.8 or less. The fin having a rectangular cross section as referred to in the present invention is different from a high-thin fin shape such as a fin manufactured by a slot rolling method, for example. In the inner helical groove tube of the present invention, the plurality of fins are preferably arranged at equal intervals in the inner circumferential direction of the tube main body. In the inner helical groove tube of the present aspect, it is preferable that the cross-sectional shape of each of the fins in the cross-section of the tube main body is a rectangle having a tip angle of 0±10°, and the average value of the ratio h/f and the ratio c/f is 2.0 to 2.8. In the inner helical groove tube of the present invention, it is preferable that the cross-sectional shape of each of the fins is rectangul