JPS6014280B2 - Heat exchanger with fins - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a finned heat exchanger, which reduces the contact thermal resistance between the fins of the finned heat exchanger and the heat exchanger tube, improves the thermal conductivity of the heat transfer tube wall part, and improves the thermal conductivity of the heat exchanger tube. A finned heat exchanger with good heat transfer performance is now available at a low price even when using polymeric materials with low thermal conductivity, such as rubber tubes or synthetic resin tubes, which were considered unsuitable for heat transfer support for finned heat exchangers. The purpose is to provide

The front view of a conventional finned heat exchanger is shown in Fig. 1, and Fig. 2 shows its front view.
As shown in the figure's 0-Ro cross section, a heat exchanger tube 1, a large number of fins 2 with high thermal conductivity, and a part of the fins 2 are arranged parallel to the tube axis of the heat exchanger tube 1 and surrounding the outer periphery of the heat exchanger tube 1. It consists of a bent fin collar 3, and is constructed by covering the coal-fired tube 1 and bringing the outer periphery of the heat exchanger tube 1 and the fin collar 3 into close contact in order to maintain good thermal contact between the heat exchanger tube 1 and the fins 2. It had been.

In the fin heat exchanger configured in this way, it is necessary to use a relatively flexible and extensible metal tube such as copper or aluminum as the material of the heat exchanger tube 1, and the fins that are a part of the heat exchanger tube 1 and the fins 2 must be used. Since the heat transfer tube 1 is brought into close contact with the collar 3 by tube expansion, there are restrictions on the material that can be used for the heat transfer tube 1, and its external shape remains the same as when it was manufactured, but it can be changed depending on the installation situation without affecting the heat transfer performance. was difficult. In view of this point, the present invention replaces the fin collar 3 with the heat exchanger tube 1.
This is an attempt to eliminate the drawbacks of conventional heat exchangers with fins, such as limitations on heat tube material and fixed shape, without deteriorating heat transfer performance.

The details of this invention will be explained below with reference to illustrated embodiments.

3 to 6 clearly explain the features of this invention in comparison with a conventional finned heat exchanger.

1 is a heat exchanger tube made of a thermoplastic polymer material with a low heat exchange coefficient such as rubber or synthetic resin; 2 is a metal fin with good thermal conductivity; one end of this is parallel to the heat exchanger tube 1; A newly bent fin collar 3 is embedded near the center of the tube wall portion of the heat exchanger tube 1 and is integrally formed with the heat exchanger tube 1. As shown in FIG. 5, the fin 2 is cut in advance at the center of a fin collar 3 to form a symmetrical shape, and a penetrating hole or cutout 4 is formed in the fin collar 3. There is.

In the finned heat exchanger configured as described above, heat from the heat medium flowing in the heat transfer tube 1 is first transferred to the inner surface of the heat transfer tube 1, and then transferred from the inner surface through the tube wall portion by conduction.

Heat is transferred from the pipe wall to the fin collar 3 embedded therein by conduction, and heat is transferred from the outer surface of the fin 2, which is integrated with the fin collar 3, to the fluid flowing between the fins. moves, and the fluid inside the tube and the fluid outside the tube exchange heat. In the above heat exchange process, when a material with low thermal conductivity is used for the tube material, if the fins 2 are attached to the outer circumference of the tube as in the conventional case, the thermal resistance of the tube wall portion or the relationship between the fins 2 and the heat exchanger tube 1 will increase. The heat transfer performance of a finned heat exchanger deteriorates due to contact thermal resistance, etc., but according to the present invention, the fin collar 3 with excellent thermal conductivity is embedded near the center of the tube wall, so the tube wall The thermal resistance of the finned heat exchanger is approximately half that of when fins are attached to the outer circumference of the tube, and even if a material with low thermal conductivity is used for the tube material, the heat transfer performance of a finned heat exchanger may be significantly reduced. Moreover, since the fin 2 is divided into multiple pieces in advance,
When attaching to the heat exchanger tube 1, it is not necessary to insert the heat exchanger tube 1 from one end as in the case of a follower, and the workability is good. Moreover, since the tube and the fin are completely joined, the contact resistance can be reduced to zero.

In particular, in the fin collar 3 portion of the fin 2, a penetrating hole or notch 4 is provided, so that a portion of the thermoplastic polymer material constituting the heat exchanger tube 1 escapes into this hole or notch 4 when the fin 2 is embedded. , resulting in fin color 3
will definitely be embedded.

7 to 12 show examples in which the shape of the fin 2 is changed in various ways.

The shapes of these fins are configured as appropriate depending on the convenience of manufacturing or using the finned heat exchanger, and FIG. It is divided into many parts along the .

It is the same as the former that the three fin collars of each divided piece are embedded in the tube meat group. FIG. 8 shows a plate-shaped fin bent into a U-shaped fin 2, in which three fin collars are embedded in the tube wall parallel to the tube axis.

FIG. 9 is a sectional view thereof, and FIG. 10 is a perspective view of the fin 2.

FIG. 11 is an example in which the long U-shaped fin shown in FIG. 10 is cut into shorter pieces. FIG. 12 shows that fin material is formed into an L-shape to form fins 2 and fin collars 3.
Three parts of the fin collar are embedded in the tube wall part of the coal heating tube 1.

It is of course possible to construct a finned heat exchanger by cutting long L-shaped fins into a large number of short fins as shown in FIG. As described above, the present invention forms the fin portion and the fin collar portion using a fin material with good thermal conductivity for convenience in manufacturing or processing the heat exchanger, and the fin collar portion is attached to the wall portion of the heat exchanger tube. In order to configure a heat exchanger with fins by embedding the heat exchanger in the heat exchanger, a heat transfer tube that allows the heat medium to flow inside, and a plurality of metal fins with good thermal conductivity are attached to this heat transfer tube in a direction that intersects with the tube axis. In the heat exchanger with fins, the heat exchanger tube is made of a thermoplastic polymer material and has a circular cross section, and the fins are divided in advance into a plurality of pieces in the circumferential direction of the heat exchanger tube, and A fin collar bent parallel to the heat exchanger tube is provided at each end, a penetrating hole or notch is formed in the fin collar, and a plurality of fins are arranged in the circumferential direction of the heat exchanger tube. Since the fin collar part is embedded in the pipe wall of the 6-reed heat tube, even if the material of the 6-reed heat tube is a thermoplastic polymer material with a thermal conductivity of 4. The shape of the finned heat exchanger can be freely manufactured without significantly reducing the exchange rate, and even after manufacturing, the heat exchanger tube can be easily bent or otherwise processed.

In addition, the six-reed heat tube can be made of inexpensive materials, and the fins can be easily attached and reliably embedded, so the whole can be constructed at low cost.

[Brief explanation of drawings]

Fig. 1 is a front view of a conventional finned heat exchanger, Fig. 2 is a low D sectional view thereof, Fig. 3 is a front view of a finned heat exchanger showing an embodiment of the present invention, and Fig. 4 is a front view of a conventional finned heat exchanger. Its W-W sectional view,
FIG. 5 is a front view of the fin, FIG. 6 is a sectional view of the fin, FIG. 7 is a front view of another embodiment of the fin, and FIG. 8 is a further embodiment of the present invention. FIG. 9 is a longitudinal sectional view of the fin heat exchanger, FIG. 9 is a KK sectional view, FIG. 10 is a perspective view of the fin shown in FIG. 8, and FIG. FIG. 12 is a longitudinal sectional view of a finned heat exchanger showing still another embodiment of the present invention. In addition, the same reference numerals in the figures indicate the same or equivalent parts, 1 is a heat exchanger tube, 2 is a fin, 3 is a fin collar, and 4 is a hole or notch. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] 1. In a heat exchanger with fins, which includes a heat transfer tube through which a heat medium flows, and a plurality of metal fins with good thermal conductivity attached to the heat transfer tube in a direction intersecting the tube axis, the heat transfer tube is made of thermoplastic material. The fins are made of a polymer material and have a circular cross section, and the fins are divided into a plurality of pieces in the circumferential direction of the heat exchanger tube, and one end of each of these fins is folded parallel to the heat exchanger tube. A bent fin collar is provided,
A heat exchanger with fins in which a penetrating hole or notch is formed in the fin collar, a plurality of fins are arranged in the circumferential direction of the heat exchanger tube, and the fin collar portion is embedded in the wall of the heat exchanger tube. .