JPS61107097A - Heat exchanger - Google Patents

Abstract

PURPOSE:To facilitate the heat transfer with an increase in resistance of air passage being suppressed, by putting a plurality of fins together, passing a heat transfer pipe through a heat transfer pipe through-hole, and contacting colors and the heat transfer pipe firmly. CONSTITUTION:In a heat exchanger, each fin 11 having a thickness on the order of 80-100mum is formed with a heat transfer pipe through-hole 12 around which colors 13 arranged, and a flare 14 is formed around the inner circumference of each color 13 and is bent outward with respect to the heat transfer pipe through-hole 12. Two projections 13 are extended from the fin 11 in a circumferential space of the heat transfer pipe through-hole 12. The projections 13 are for restricting the size of the fin pitch, and the uprise size l1 of the color 13 is equal to the fin pitch. The uprise size l2 of the color 13 is smaller than l1. In this arrangement, the heat transfer pipe 16 and the fins 11 can be brought in firm contact with each other, and the heat resistance at the contact section of each fin 11 and the heat transfer pipe 16 is made low to facilitate the heat transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cross-fin tube heat exchanger that is often used in air conditioners and the like.

Conventional configuration and its problems In order to promote heat transfer between the heat exchanger and the airflow flowing between the fins, it is conceivable to increase the heat transfer area of the heat exchanger unit volume.

Conventionally, in cross-fin tube heat exchangers, the fin pitch has been reduced (approximately 2 mm or less) based on this idea. In addition, reducing the fin pitch also increases ventilation resistance and impedes heat transfer, but in order to suppress this and to reduce fin material costs, the fin wall thickness is also reduced. It was

Meanwhile, a conventional manufacturing method for joining the fins and heat transfer tubes of this type of heat exchanger is as follows.

1. Provide a through hole in the fin that is larger than the outside diameter of the heat transfer tube. Further, a collar for regulating the fin pitch is provided around the heat exchanger tube through hole.

2. Insert the heat exchanger tube into the heat exchanger tube through hole.

3. Insert a tube expansion ball larger than the inner diameter of the heat transfer tube into the heat transfer tube to expand the heat transfer tube and bring it into pressure contact with the inner surface of the collar.

If the fin wall thickness is made too thin in order to adopt the method described above, the collar will crack due to the force F1 applied to the inner surface of the collar 2 provided on the fin 1 due to tube expansion, as shown in Fig. 4, and the collar will be forced into pressure contact. becomes impossible. For this reason, the adhesion between the fins 1 and the heat exchanger tubes 2 deteriorates, which becomes a factor that inhibits heat transfer from the heat exchanger tubes 2 to the fins 1. For this reason, there is a limit to reducing the thickness of the fin.

Since the rounded collar also has the role of regulating the fin pitch, it covers the entire surface of the heat exchanger tube, and the apparent thickness of the upper part of the heat exchanger tube increases, increasing thermal resistance.

Therefore, this was also one of the factors that inhibited heat transfer.

Purpose of the Invention The present invention solves these conventional problems, and aims to improve heat transfer by increasing the heat transfer area per unit volume of a heat exchanger, reducing thermal resistance, and suppressing an increase in ventilation resistance. to promote
The objective is to obtain a heat exchanger that can suppress an increase in fin material costs.

Structure of the Invention The heat exchanger of the present invention includes a collar formed around a heat exchanger tube through hole provided in a fin, and a flare formed by curving the entire inner circumference of the collar outward with respect to the heat exchanger tube through hole. form,
Further, a protrusion is formed in the vicinity of the heat exchanger tube through hole of the fin, the height of the collar is lower than the height of the protrusion, and a plurality of the fins thus formed are stacked to form the heat exchanger tube. The heat exchanger tube is penetrated through a heat tube through hole, and the collar and the heat exchanger tube are brought into close contact with each other. With the above configuration, it is possible to increase the heat transfer area per unit volume of the heat exchanger, reduce thermal resistance, suppress an increase in ventilation resistance, promote heat transfer, and suppress an increase in fin material costs.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In Figures 1 and 2, 11 is 80~ thinner than the conventional example.
A fin with a wall thickness of about 10011 m, 12 is a heat exchanger tube through hole formed in the fin 11, 13 is a collar provided around the heat exchanger tube through hole 12, and a heat exchanger tube through hole is provided on the entire inner circumference of the collar 13. A flare 14 is formed by curving outward with respect to 12.

A protrusion 5 base 2 is provided in the gap in the outer circumferential direction of the heat exchanger tube through hole 12. Two risers 15 are formed standing up from the fins 11.

The protrusion 15 is provided for regulating the fin pitch. Therefore, the rising dimension of the protrusion 15 is equal to the fin pitch.

The rising dimension 22 of the collar 13 is such that the strength of the collar 13 will not be maintained if the fin wall is thin, so if it is made high, the strength of the collar 13 will not be maintained, and the entire heat transfer tube 16 is not covered with the collar 13, but a portion is directly exposed to the fluid for heat exchange. For, I! ,1
It's small.

A plurality of fins 11 configured in this way are stacked together,
FIG. 3 shows a cross-fin tube heat exchanger constructed by inserting and expanding heat transfer tubes 16. In addition, Figure 1,
Components that are the same as those in FIG. 2 are given the same numbers and their explanations will be omitted.

As shown in FIG. 3, the fin pinch is limited and determined by the contact of the protrusion 15 with the adjacent fin surface. Furthermore, by forming the flare 14 on the collar 13, the fin base 17a and the tip 17b of the collar 13 have considerable strength, and even if the heat transfer tube 16 is expanded in the conventional manner, the flow 1, - Even though the inner wall thickness is small, the collar 13 does not crack, so the heat exchanger tube 16 and the fin 11 can be brought into close contact with each other. Therefore, the thermal resistance at the contact portion between the fins 11 and the heat transfer tubes 16 is reduced, and heat transfer is promoted.

However, the ability to reduce the thickness of the fins does not mean that even though the fin pitch is narrower than before, the amount of air blown decreases significantly in order to suppress the increase in ventilation resistance. Therefore, the amount of heat transfer increases as the heat transfer area increases. It is also possible to reduce the cost of fin materials.

In addition, the rise of the collar 13/burr dimension overflow is the protrusion 15
Because the two dimensions are smaller than 1°C, the heat exchanger tube 1
A surface 18 is formed where 6 is in direct contact with the airflow. This side 1
8 has a lower thermal resistance than the other parts covered with the collar 13, so heat transfer can be promoted more than in the conventional case where the entire surface of the heat exchanger tube is covered with the collar.

Effects of the Invention As described above, according to the present invention, a collar is formed around the heat exchanger tube through hole provided in the fin, and the entire inner circumference of the collar is curved outward with respect to the heat exchanger tube through hole. further, the height of the collar is made lower than the height of the protrusion, a plurality of the fins formed in this manner are stacked, a heat exchanger tube is passed through the heat exchanger tube through hole, and the collar and the By closely fitting the heat transfer tubes, the fin wall thickness can be made thinner than before, increasing the heat transfer area of the unit volume of the heat exchanger, reducing thermal resistance, and suppressing the increase in ventilation resistance. A good heat exchanger can be obtained by promoting heat, suppressing the increase in fin material cost, and using the same manufacturing method as the conventional method.

[Brief explanation of drawings]

FIG. 1 is a front view of a heat exchanger fin according to an embodiment of the present invention, FIG. 2 is a half-sectional view of the same side, and FIG. 3 is a half-sectional view of a heat exchanger according to an embodiment of the present invention. FIG. 4 is a half-sectional view of a conventional heat exchanger. 11...Fin, 12...Heat transfer tube (hole,
13...Color, 14...Reflare,
15... Protrusion, 16... Heat exchanger tube.

Claims (1)

[Claims] A collar is formed around the heat exchanger tube through hole provided in the fin,
The entire circumference of the tip of the collar is curved outward with respect to the heat exchanger tube through hole to form a flare, and a protrusion is further formed in the vicinity of the heat exchanger tube through hole of the fin, so that the height of the collar is The heat exchanger has a height lower than that of the protrusion, a plurality of the fins formed in this manner are stacked, the heat exchanger tube is passed through the heat exchanger tube through hole, and the collar and the heat exchanger tube are brought into close contact.