JPH0251114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a cooling device for a refrigerator or the like that includes a blower and an evaporator in a duct.

(b) Prior art Publication of Utility Model Publication No. 49-29481 (JPC.68A41) states:
evaporation tubes arranged in parallel and in communication with each other;
fins, and second fins each having one side approximately half the width of the first fins, and second fins are arranged vertically and alternately between the first fins, and there is a part where the second fins are not provided. A finch-tube type evaporator is shown, which is characterized by parallel ventilation passages.
With such a configuration, even if the part where the second fin is attached is blocked due to frost formation, the ventilation in the upper and lower parts where the second fin is not attached will not be obstructed, and the space between the fins will be completely blocked due to frost clogging. Moreover, even in the event of frost formation, it forms a ventilation detour and achieves the effect of uniform heat exchange. In addition, the ventilation path between the first fins without fins, which is the upper or lower stage of the second fin, is the second fin.
Since the height and width are the same as the fins, the amount of air passing through the ventilation passage where the static pressure is lower is greater than the amount of air passing between the first and second fins where the static pressure is higher. The wind passing through the duct came into contact only with the first fin and flowed out of the evaporator. As a result, a drawback occurred in that heat exchange of the air passing through the ventilation passage was poor (in other words, the amount of frost formed on the first fin surface was small). Also, since this evaporator flows the reduced pressure liquid refrigerant from the opposite side of the wind passage direction, the temperature is higher at the rear part, which is the air outlet side, than at the front part, which is the air inlet side, of both the first and second fins. As time passes, the frost that initially adheres to the front part gradually transfers to the rear part due to the evaporation effect of the wind and the temperature gradient of both the first and second fins. Refrigerators have a low load entering the compartment when closed.
The frost that has moved to the rear of both the first and second fins causes the rear to become clogged before the front, requiring defrosting.
Cooling operation time has become shorter.

(c) Purpose of the invention The purpose of the present invention is to solve the drawbacks of the prior art.

(d) Structure of the invention In a cooling device in which an evaporator and a blower for circulating cold air heat exchanged with the evaporator are disposed in a duct, the evaporator is connected to evaporation pipes arranged in parallel in a meandering manner; The evaporator is composed of first fins installed perpendicularly to the evaporator with an appropriate pitch, and second fins having a smaller surface area than the first fins and installed between the first fins, A ventilation passage without fins is formed in both the air inlet and outlet parts between one fin and in a part orthogonal to these parts, so that the cold air passing between the two fins is detoured in a dogleg shape, and the air passage on the air outlet side is A cooling device that stores frost that has transferred to the ventilation duct.

(E) Embodiments of the Invention Below, embodiments of the present invention will be described based on the drawings. 1 is a main body composed of a heat insulating wall 4 equipped with a door 3 that can open and close an opening 2 for loading and unloading products on the front side; In this cooling device, such as a refrigerator, a partition plate 5 is arranged at an appropriate distance from the inner wall of the heat insulating wall, a plate fin type evaporator 6 and an axial flow blower 7 are arranged, and A cold air circulation duct 10 having an air outlet 8 along the inside edge and an inlet 9 along the inside lower edge of the opening, a plurality of horizontally arranged shelves 11, and a vertically arranged fluorescent lamp 12. By forming a storage chamber 13 equipped with to cool the storage chamber.

Reference numeral 14 denotes a machine room formed directly below the heat insulating wall, in which a refrigerant compressor 15, a plate fin condenser 16, and an axial blower 17, which together with the evaporator constitute a refrigeration cycle, are housed.

As shown in FIGS. 1 and 2, the evaporator includes meandering evaporation tubes 18 that are arranged in parallel in a plurality of rows and stages and that form refrigerant flow paths, each of which is perpendicular to the evaporation tubes, A plurality of first fins 19, 19... are attached to each other with a pitch (L), and a plurality of first fins are attached alternately with a pitch of L/2 between each of the first fins, perpendicular to the evaporation tube. The second of many
It is composed of fins 20, 20, . . . and allows the reduced pressure liquid refrigerant to flow in the direction from X to Y in FIG. The width of the vertical height and depth of this second fin is the same as that of the first fin.
9, 19..., that is, the surface area of the second fins 20, 20... is slightly shorter than that of the first fin 1.
The fins are smaller than those of the first fins 19, 19, and the upper part on the air outlet side, the lower part on the air inlet side, and the front part perpendicular to both the upper and lower parts are the fins. No part and no part, these three parts are ventilation passages 21, 22, 2
It is set at 3. Of these ventilation passages, the ventilation passage 22 on the air inlet side has a fin pitch of L/2 and has a viscous Due to the increased resistance, the static pressure becomes greater than that in the other ventilation passages 21, 23, and the cold air to be heat exchanged passes through the evaporator 6 as indicated by the arrow in FIG. In addition, if we look at the magnitude relationship between the static pressures of both the ventilation passages 21 and 23, since the ventilation passage 21 is deeper than the ventilation passage 23,
21<23.

Referring to FIG. 1, the flow of cold air passing through the evaporator 6 will be explained in detail.
Out of (b) and (c), (i) passes through the ventilation passage 23 with a small static pressure, but the ventilation passage 2 with a larger static pressure than this ventilation passage.
2. Under the influence of the ventilation passage 21 with low static pressure, it is detoured in an approximately dogleg shape, and after passing through the lower ventilation passage 22 where static pressure is high, the ventilation passage 23 side of the front stage where static pressure is low The air is further directed to the upper ventilation passage 21 side where the static pressure is lower than that of this ventilation passage 23, and passes through the evaporator 6. That is, the cold air passing through the evaporator 6 detours in a dogleg shape as a whole due to the magnitude relationship of the static pressures in the ventilation passages 21, 22, 23, and as a result, the first fins 19, 19, . . . 2
The amount of cold air coming into contact with the surfaces of the fins 20, 20 increased, and it was possible to improve the heat exchange of the evaporator 6.

In addition, in addition to the ventilation passage 22 on the air inlet side, the ventilation passage 21 is also formed on the air outlet side, so that the air initially adheres to the air inlet side edges of the first fins 19, 19... and the second fins 20, 20... Even if the frost gradually transfers to the air outlet side edge due to the temperature gradient of the two fins and the evaporation effect of cold air, the ventilation passage 21 can slow down the clogging of the air outlet side by the frost, and as a result, the air The air outlet side is no longer clogged with frost earlier than the inlet side, and it is possible to lengthen the cooling operation time during which frost transfer is absorbed by the ventilation passage 21.

(F) Effects of the Invention Since the present invention is configured as described above, it achieves the effects listed below.

Since ventilation passages are formed around the second fin in at least three directions, the cold air passing through the evaporator can be detoured in a dogleg shape and brought into contact with both the first and second fins. The passage distance between the fins was increased, making it possible to improve heat exchange in the evaporator.

Since ventilation channels are formed on both the air inlet and outlet sides of the evaporator, even if frost transfer occurs, it is possible to avoid the situation where the air outlet side is blocked by frost before the air inlet side. This allows the frost transfer to be absorbed by the ventilation duct on the air outlet side, making it possible to lengthen the cooling operation time.

[Brief explanation of the drawing]

The drawings all show embodiments of the cooling device of the present invention,
Figure 1 is an enlarged view of Figure 3B, Figure 2 is Figure 1A-
A' sectional view and FIG. 3 are longitudinal sectional views of the cooling device. 6... Evaporator, 7... Blower, 10... Duct, 18... Evaporation pipe, 19, 19... First fin, 20, 20... Second fin, 21, 22, 2
3...Ventilation duct.

Claims (1)

[Claims] 1. In a cooling device in which an evaporator and a blower for circulating cold air heat exchanged with the evaporator are arranged in a duct, the evaporator is connected to an evaporator pipe arranged in a meandering manner and to the evaporator, respectively. The structure includes first fins that are orthogonal to each other and are installed at an appropriate pitch, and second fins that have a smaller surface area than the first fins and are installed between the first fins, and the air between the first fins is A cooling device in which a ventilation passage without fins is formed in both the inlet and outlet parts and in a part orthogonal to these parts.