JPH03294033A - Manufacture of heat exchanger - Google Patents

Abstract

PURPOSE:To improve the heat exchange capacity by expanding a heat exchanger tube in a state that grooves of a rugged shape are eliminated temporarily by a temperature variation and the inside surface of the heat exchanger tube is almost flattened, and allowing a heat exchanger fin and the heat exchanger tube to adhere closely to each other. CONSTITUTION:Heat exchanger fins are arranged in parallel at a prescribed interval, and gas is allowed to flow between them. A heat exchanger tube 11 is inserted vertically into this heat exchanger fin. The heat exchanger tube 11 is constituted of a shape memory alloy or a shape memory resin 15 which is subjected to reversible transformation in accordance with a temperature variation. Also, grooves 12, 13 of a rugged shape are formed in the heat exchanger tube 11. Subsequently, in a state that the grooves 12, 13 of a rugged shape are eliminated temporarily by a temperature variation and the inside surface of the heat exchanger tube 11 is almost flatted, the heat exchanger tube 11 is expanded, and the heat exchanger fin and the heat exchanger tube 11 are allowed to adhere closely to each other. In such a way, a heat transfer coefft. of the inside of the tube being equal to a single tube can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat exchanger that transfers heat between a refrigerant and a fluid such as air, which is widely used in refrigeration equipment and air conditioning equipment.

BACKGROUND OF THE INVENTION In recent years, there has been a demand for higher efficiency in equipment, and there is an urgent need to improve the efficiency of heat exchangers used in refrigeration equipment and air-source heat pump air conditioners.

An example of a conventional method for manufacturing a heat exchanger will be described below with reference to the drawings.

Figure 4 is a perspective view of a conventional heat exchanger, where 3o is a heat exchanger;
31 is a heat transfer fin arranged in parallel at regular intervals; 32 is a heat transfer tube inserted into the heat transfer fin 31 at right angles and has a spiral groove formed on its inner surface; the air flow is indicated by an arrow. . FIG. 5 is a side view of the heat transfer tube 32 when it is a single tube, 33 is a substantially spiral groove machined into the heat transfer tube 32, and 34 is a substantially triangular peak of the groove 33. FIG. 6 shows a tube expansion process in which the heat transfer fins 31 and the heat transfer tubes 32 are brought into close contact with each other, and 35 is a mandrel jig, and the arrow indicates its insertion direction. FIG. 7 is a side view of the heat exchanger tube 32 after expansion, and 36 is a mountain deformed by expansion. FIG. 8 compares the tube inside heat transfer coefficient and evaporation performance during refrigerant evaporation between the heat transfer tube 32 alone and the heat exchanger.

The operation of the conventional heat exchanger configured as shown in FIG. 4 will be explained below. Air flows between heat transfer fins 31 as shown by the arrow, and refrigerant flows through heat transfer tubes 32 to exchange heat. . At this time, boiling or condensation of the refrigerant is promoted by the grooves 33 and the substantially triangular peaks 34 of the heat transfer tube 32, improving the heat transfer coefficient inside the tube and improving the heat exchange performance.

Problem to be Solved by the Invention However, in the heat exchanger manufacturing method as described above, the approximately triangular peaks 34 of the heat exchanger tubes 32 shown in FIG. 36 and becomes the deformed mountain 36 shown in FIG. As a result, as shown in Fig. 8, when compared during refrigerant evaporation, the heat exchanger tube 32
The heat transfer coefficient inside the tube is lower in the heat exchanger 30 than in the heat exchanger 30 alone, and theoretical calculations based on the performance of the heat exchanger tube alone also have the problem of decreasing evaporation performance. In addition, in Fig. 8,
A is the data for a single tube, B is the calculation ability for the single tube data,
C and D show data for the heat exchanger.

Also, when comparing the refrigerant condensation, there is a problem that the heat transfer coefficient inside the tube is lower in the heat exchanger 3o than in the heat exchanger tube 32 alone, and the condensation performance is lower than in the theoretical calculation. was.

In view of the above problems, the present invention provides a heat exchanger that exhibits heat transfer performance equivalent to that of a single tube.

Means for Solving the Problems In order to solve the above problems, the method for manufacturing a heat exchanger of the present invention includes heat transfer fins that are arranged in parallel at regular intervals and through which gas flows, and a heat exchanger that is perpendicular to the heat transfer fins. The heat exchanger tube is inserted into the tube and has an uneven groove on the inner surface made of a shape memory alloy or shape memory resin that undergoes reversible transformation in response to temperature changes. The heat transfer tube is expanded with the inner surface of the heat transfer tube made substantially flat, and the heat transfer fins and the heat transfer tube are brought into close contact with each other.

Function The present invention uses the above-described manufacturing method to ensure a tube inside heat transfer coefficient equivalent to that of a single tube and improve heat exchange performance.

EXAMPLE Hereinafter, a method for manufacturing a heat exchanger according to an example of the present invention will be described with reference to the drawings.

Conventionally, a heat exchanger consists of heat transfer fins (not shown) arranged in parallel at regular intervals, inserted at right angles to the heat transfer fins, and made of a shape memory alloy or a shape memory alloy that undergoes reversible transformation in response to temperature changes on the inner surface. It is composed of a heat exchanger tube 11 made of shape memory resin and provided with uneven grooves.

FIG. 1 is a side view of a heat exchanger tube 11 used in the heat exchanger of the present invention, in which 12 is a concave shape, 13 is a convex shape, 14 is a groove formed by the above-mentioned uneven shape, and 16 is a groove formed by the above-mentioned 14 Shape memory alloy or shape memory resin that forms the grooves. FIG. 2 is a side view of the heat exchanger tube 11 at the time of tube expansion in which the heat exchanger fins and the heat exchanger tube are brought into close contact with each other, and 22 is the deformation of the recess 12, and 23 is the deformation of the convex portion. 24 is the substantially flat groove 14;
It is. FIG. 3 compares the tube inside heat transfer coefficient and evaporation performance during evaporation between the heat transfer tube 11 alone and the heat exchanger.

The method for manufacturing the heat exchanger of the present invention will be explained below. FIG. 1 is a side view of the heat exchanger tube before and after expansion, and the tube expansion process shown in FIG. It is done. After pipe expansion, the grooves shown in Figure 1 are re-formed due to temperature changes, maintaining the same groove shape before and after pipe expansion.

As a result, during evaporation, as shown in FIG.
Achieves the same heat transfer coefficient inside the tube as a single heat exchanger,
The performance of the conventional heat exchanger is improved.

Note that in No. 30, A is the data of the single tube used in the present invention, B is the calculation ability of the single tube, and Σ.

F shows data for the heat exchanger of the present invention.

As described above, by providing the inner surface with uneven grooves made of shape memory alloy or shape memory resin that undergoes reversible transformation in response to temperature changes, the heat exchanger exhibits superior heat exchange performance compared to conventional products. This is a manufacturing method that can provide the following.

Effects of the Invention As described above, the present invention consists of heat transfer fins that are arranged in parallel at regular intervals and through which gas flows, and that are inserted perpendicularly to the heat transfer fins and that have a structure that undergoes reversible transformation in response to temperature changes on the inner surface. The heat exchanger tube is made of a shape memory alloy or shape memory resin and has grooves in an uneven shape. By expanding the heat tube and bringing the heat transfer fins into close contact with the heat exchanger tube, a heat transfer coefficient inside the tube equivalent to that of a single tube is secured, and the heat exchange capacity is improved compared to the conventional method.

[Brief explanation of drawings]

FIG. 1 is a side view showing the shape of a heat transfer tube used in a heat exchanger according to an embodiment of the present invention before and after expansion when the heat transfer tube is brought into close contact with heat transfer fins, and FIG. 2 is a side view showing the shape of the heat transfer tube of FIG. Figure 3 is a characteristic diagram comparing the performance of the heat exchanger with the heat exchanger tube; Figure 4 is a perspective view of a conventional heat exchanger; Figure 6 6 is a side view of a heat transfer tube used in a conventional heat exchanger before expansion, FIG. 6 is a cross-sectional view showing the tube expansion process in which the heat transfer tube of FIG. FIG. 8 is a side view of the heat exchanger tube after tube expansion, and FIG. 8 is a characteristic diagram comparing the performance of the heat exchanger tube and the heat exchanger in a heat exchanger manufactured by a conventional manufacturing method. 11...Heat transfer tube, 14...Substantially spiral groove, 15...Shape memory alloy or shape memory resin, 31...Heat transfer fin.

Claims (1)

[Claims] Heat transfer fins arranged in parallel at regular intervals, through which gas flows, and projections and depressions inserted perpendicularly into the heat transfer fins and made of a shape memory alloy or shape memory resin that reversibly transforms in response to temperature changes on the inner surface. The uneven grooves are temporarily removed due to a temperature change, and the heat exchanger tube is expanded with the inner surface of the heat exchanger tube made substantially flat, and the heat exchanger fins and the heat exchanger tube are expanded. A method of manufacturing a heat exchanger that brings the