JP2774820B2 - Heat exchanger - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger used for an evaporator of a refrigerator, a freezer, a freezing showcase, and the like, in particular, a large number of independent fins and a meandering refrigerant pipe inserted therethrough. The present invention relates to a fin-tube heat exchanger comprising:

2. Description of the Related Art When this kind of heat exchanger is used for the above-mentioned applications, since the surface temperature is used under a condition of 0 ° C. or less,
The occurrence of frosting is inevitable. For this reason, as shown in FIG. 11, a heat source (100) such as a heater may be provided near one side of the heat exchanger (101) as a defrosting device. In the figure, (102) is a meandering refrigerant pipe, (10)
3) is a number of independent fins inserted through the straight pipe section of the pipe.

Problems to be Solved by the Invention In this case, defrosting is performed by radiant heat from the heat source (100), heat conduction and convection by the independent fins (103). However, as the distance from the heat source (100) increases, heat transfer becomes more difficult. Therefore, there is a disadvantage that the overall defrosting efficiency is not sufficient. Such a drawback occurs more remarkably as the number of meandering stages of the refrigerant pipe (102) increases, in other words, as the distance from the heat source to the fastest part increases. Further, when the heat source (100) is operated for a long time to perform sufficient defrost, another drawback is that power consumption increases.

The present invention has been made in order to solve such a drawback, and provides a heat exchanger that can surely transmit heat from a heat source to a range that radiant heat does not directly reach, thereby improving defrosting efficiency. It is intended for.

Means for Solving the Problems In order to achieve the object described above with reference to the reference numerals in the drawings, a number of independent fins (1) are provided on each straight pipe portion (2a) of a meandering refrigerant pipe (2). In the heat exchanger in which the defrosting heat source (9) is arranged outside the outermost straight pipe portion, the heat exchanger extends over all the straight pipe portions (2a) of the refrigerant pipe (2). One or a plurality of continuous fins (3) are provided in a pipe fitting notch (7) provided at an intermediate portion excluding both ends of the straight pipe portion (2a) and at a side edge thereof.
This is achieved by a heat exchanger characterized in that (7 ') is fitted in each straight pipe portion (2a) of the pipe (2) so as to be provided in close contact with each other.

The heat given to the continuous fins (3) from the heat source (9)
The heat is transmitted to the straight pipe portions (2a) of the refrigerant pipe (2) that is in contact with the continuous fin by heat conduction inside the continuous fin, and further transmitted from the pipe (2) to the independent fin (1).

EXAMPLE Next, an example in which the present invention is applied to an aluminum evaporator for a freezer will be described.

1 and 2, (A) is an evaporator, (1) is an independent fin composed of a number of small pieces, (2) is a meandering refrigerant pipe, (3) is a continuous fin, and (4) ( 4) is a side plate, and (5) is an accumulator.

The refrigerant pipe (2) is a front and rear pipe row (21) (22)
Is formed to meander in the vertical direction in a shape having a straight pipe portion (2a) and a U vent portion (2b). On the other hand, as shown in FIG. 5, the independent fin (1) has a pair of holes (6) and (6) for inserting refrigerant pipes in the front and rear, and the front and rear refrigerant pipes (2) are inserted in the holes (6). Is inserted in a state parallel to and adhered to each straight pipe portion (2a) of the refrigerant pipe.
Further, the continuous fin (3) is composed of one long fin, and as shown in FIG. 4, a plurality of cutouts (7) for fitting a refrigerant pipe are formed on one side edge in the width direction. I have. As shown in FIGS. 1 and 3, the continuous fins (3) are located near both ends and near the center in the intermediate portion of the refrigerant pipe (2) except for both ends of the straight pipe portion (2a). Three straight pipes (2a) are arranged in the notch (7) from the front side of the front pipe row (21) in the vertical direction.
Are fitted so as to straddle each straight pipe portion (2a).

In order to configure the evaporator (A), first, as shown in FIG. 5, a pair of refrigerant pipe insertion holes (6) are opened before and after a number of independent fins (1). Then, the fins are arranged so as to be parallel to each other, and a U-shaped refrigerant pipe (2) is inserted into each of the holes (6) as shown in FIG.
If necessary, these are expanded so as to be in close contact with the periphery of the hole over the entire circumference. At this time, the arrangement of the group of independent fins (1) is arranged so as to avoid the part where the meandering bending of the refrigerant pipe (2) is performed as shown in FIG.

Next, the refrigerant pipe (2) is bent in a meandering manner so that a portion having each independent fin (1) group becomes a straight pipe portion (2a). As shown in FIGS. 7 and 8, in order to facilitate the bending and to prevent the pipe from being crushed, a portion of the refrigerant pipe (2) serving as a U vent portion (2b) along the outer periphery is formed along the outer periphery. It is also recommended to provide a plurality of annular grooves (8) in advance. Preferably, the groove (8) has a depth h of 0.2 to 2 mm, a width m of 1 to 6 mm, and a groove pitch p of 3 to 15 m.
It is good to set to m. Pipe bent in this way (2)
, Side plates (4) and (4) are attached to the U-bend portions (2b) and (2b).

Next, a notch (7) for pipe fitting is formed on one side edge of the independent fin (1), and each straight pipe portion (2a) in the vertical direction of the front pipe example (21) is formed in this notch (7). After fitting, the continuous fins (3) are tightly attached across the straight pipe portions (2a) to obtain the desired evaporator (A).

The evaporator (A) connects both ends of the refrigerant pipe (2) to a piping system of a refrigeration cycle including a compressor for compressing the refrigerant and a condenser for liquefying the compressed refrigerant, and also connects a heating element such as a heater. Becoming heat source (9)
Is disposed near the lower end of the evaporator (A), and air is circulated by a blower in the direction of the arrow (W) in FIG. 1 to cool the inside of the refrigerator. At the time of defrosting, after the operation of the refrigeration cycle is stopped, the heat source (9) is energized. Then, due to the radiant heat to be generated from now on, the area covered by the heat source is directly heated, and the melting of frost proceeds. In addition, the radiant heat given to the lower end of the continuous fin (3) is transmitted by the fin itself to each of the upper refrigerant pipes (2) and further transmitted from the pipe to the independent fin (1). Efficiently transmitted to the upper end of the evaporator that does not reach,
An efficient defrosting action is realized for the entire evaporator by adding a defrosting action by convection.

In the above embodiment, the pipe fitting notch (7) is provided on one side edge of the continuous fin (3) and attached to the front pipe row (21), but is attached to the rear pipe row (22). May be. Alternatively, notches (7 ') for pipe fitting are provided on both side edges of the continuous fin (3') as shown in FIGS. 9 and 10, and the continuous fin (3 ') is connected to the front and rear refrigerants. The front and rear pipes (2 ') may be fitted into the cutouts (7') by being interposed between the pipe rows. Furthermore, it is not always necessary to provide a plurality of continuous fins, but a single fin may be provided.

According to the present invention, as described above, in a heat exchanger in which a number of independent fins are attached to each straight pipe portion of a meandering refrigerant pipe by being inserted through the refrigerant pipe, all of the refrigerant pipes Since one or more continuous fins are provided in close contact with each other over the straight pipe portion, the radiant heat applied to the continuous fins from the heat source is applied to the continuous fins when performing defrosting. The heat can be directly transmitted to each straight pipe portion in contact with the continuous fin by its own heat conduction, and further transmitted from the straight pipe portion to the independent fin. Therefore, sufficient heat can be transferred to a range that is not directly affected by the radiation from the heat source, and the defrosting efficiency of the entire heat exchanger can be improved.
Moreover, even a large-sized heat exchanger having a large number of meandering stages can reliably transfer heat over a wide range, and can perform effective defrosting. In addition, it is not necessary to secure a long defrosting time for a long time, so that power consumption for driving the heat source can be reduced.

Furthermore, since the continuous fins are provided in the middle portion except for both ends of the pipe straight pipe portion, heat from the continuous fins is transmitted to both side portions of the continuous fins in each straight pipe portion,
A wide area of the straight pipe is heated. Therefore, the defrosting efficiency of the entire heat exchanger can be improved in each stage as compared with the case where the continuous fins are provided at both ends of the straight pipe portion of the pipe.

Furthermore, since the continuous fin is provided by fitting the pipe fitting notch provided on the side edge thereof to each straight pipe portion, when the continuous fin is attached to each straight pipe portion, the pipe fitting is performed. Just fit the joint notch into each straight pipe,
The work of attaching the continuous fins can be performed extremely easily as compared with the case where the continuous fins are provided with through holes and the straight pipe portion is inserted through the through holes.

[Brief description of the drawings]

FIG. 1 is a front view of the entire heat exchanger, FIG. 2 is a side view of the same, FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1, FIG. FIG. 5 is a side view showing the shape of the independent fins, FIG. 6 is a plan view showing the arrangement of the independent fins at the time of assembly, and a state in which a refrigerant pipe is inserted therein,
FIG. 9 is a front view of a portion (bent portion) where a U-bend is to be formed, FIG. 8 is an enlarged front view showing a part of FIG. 7, and FIGS. 9 and 10 show another embodiment. Fig. 10 is a side view of the continuous fin, and Fig. 10 is a state where the continuous fin of Fig. 9 is attached.
FIG. 11 is a cross-sectional view as seen from the same direction as the figure, and FIG. 11 is a schematic front view of a conventional heat exchanger. (1) ... independent fin, (2) ... refrigerant pipe, (2a)
... straight pipe, (3) (3 ') ... continuous fin, (7)
(7 ') ... notch, (9) ... heat source.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25D 21/08 F25B 47/02 F28F 1/32

Claims (1)

(57) [Claims] A straight pipe portion (2) of a meandering refrigerant pipe (2).
a) a plurality of independent fins (1) are inserted through the refrigerant pipe and attached, and the heat exchanger (9) for defrosting is disposed outside the outermost straight pipe portion; One or a plurality of continuous fins (3) are provided in the middle portion except for both ends of the straight pipe portion (2a) and on the side edges thereof, across all the straight pipe portions (2a) of the pipe (2). Heat exchange characterized by being provided in close contact with each other by fitting the pipe fitting notches (7) (7 ') into the straight pipe portions (2a) of the pipe (2). vessel.