JPS61114063A - Refrigerant evaporator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a refrigerant evaporator of a refrigeration cycle used in an automobile cooling system or the like.

(Prior Art) A conventional refrigerant evaporator is shown in Fig. 10, in which a flat tube l made of a metal with good thermal conductivity, such as aluminum, is formed into a meandering curve, and in order to promote heat exchange, a flat tube l made of a metal with good thermal conductivity, such as aluminum, is used. Heat transfer fins 3 made of metal with good heat conduction and formed into a corrugated shape are joined by brazing or the like so as to be heat conductive. A plurality of refrigerant passages 1a are provided inside the flat tube 1 by extrusion molding, and on the refrigerant inflow side and refrigerant outflow side, a refrigerant inlet vibrator 5 and a refrigerant outlet vibrator 6 are both connected to the air upstream side of the evaporator. It is designed to be placed in

In the refrigerant evaporator configured as described above, the refrigerant is
As shown by the arrow in Figure 0 (, inlet vibe 5, refrigerant distribution pipe 2,
The refrigerant flows through the flat tube 1, the refrigerant collecting pipe 4, and the outlet vibe 6 in this order, and evaporates within the flat tube 1. At this time, the flat tube 1 and the heat transfer fins 3 remove latent heat for evaporating the refrigerant from the surrounding air, so that the surrounding air is cooled. Therefore,
Air flowing from the upstream side A of the evaporator between the heat transfer fins 3 and the flat tubes 1 of the evaporator as shown by the arrow is cooled as it passes through, becomes cold air, and is discharged to the downstream side. The distribution pipe 2 and the refrigerant collecting pipe 4 are joined together by brazing, and as shown in FIG. 10, an inlet vibrator and an outlet vibe 6 made of aluminum are respectively joined by brazing.

In this case, a temperature-operated expansion valve 7 is attached to adjust the flow rate of refrigerant flowing into the flat tube 1, and a temperature-sensitive cylinder 8 for detecting the refrigerant temperature is attached to the outlet vibe 6. Since the opening degree of the valve is adjusted according to the temperature detected by the temperature sensing tube 8, the inlet vibrator 5 and the outlet vibrator 6
It is preferable to arrange them as close as possible. Also,
There is less temperature variation on the air upstream side A of the evaporator than on the air downstream side B, and high-temperature refrigerant flows through the high-pressure side pipe 9. The side is preferable. Further, the heat load on the air upstream side of the flat tube 1 is greater than that on the air downstream side, so it is necessary to flow more refrigerant to the air upstream side of the plurality of refrigerant passages 1a. Therefore, in a conventionally known refrigerant evaporator, as shown in FIG. 10, the refrigerant is introduced in the opposite direction to the flow of the wind, so that a large amount of the refrigerant flows on the air upstream side of the refrigerant distribution pipe 2.

(Problems to be Solved by the Invention) However, for this purpose, the inlet vibrator 5 must be disposed from the air upstream side to the air downstream side, and there is a problem that the piping arrangement becomes complicated.゛Therefore, the present invention aims to solve the problem of allowing a large amount of refrigerant to flow to the air upstream side of the plurality of refrigerant passages provided in the flat tube without complicating the arrangement of the piping of the inlet vibrator 5. Consider it a technical issue.

(Means for Solving the Problems) Therefore, in order to achieve the above-mentioned technical problem, the present invention provides a flat tube having a plurality of refrigerant passages, and a heat transfer foil joined to the tube in a heat conductive manner. a longitudinal portion is joined to the refrigerant inflow opening end of the flat tube such that the refrigerant introduction end is located on the air upstream side of the flat tube and the heat transfer fin, and distributes the refrigerant to the refrigerant passage. A technical means is adopted in which a refrigerant distribution pipe and a plurality of louvers are provided inside the refrigerant distribution pipe in the longitudinal direction from the refrigerant introduction end and guide the refrigerant to the refrigerant passage side.

(Function) By adopting the above technical means, the refrigerant introduced into the refrigerant distribution pipe from the air upstream side of the refrigerant evaporator is arranged in multiple rows in the flat tube by the plurality of louvers provided in the refrigerant distribution pipe. Among the refrigerant passages, the air is sequentially introduced from the upstream side to the downstream side of the refrigerant evaporator. In this case, since the amount of refrigerant on the air upstream side of the refrigerant distribution pipe is larger than that on the downstream side, a large amount of refrigerant flows into the refrigerant passage located furthest upstream of the air due to the louver, and the refrigerant on the downstream side of this refrigerant passage The remaining refrigerant is sequentially introduced into the passage in the same manner. Therefore, the flow rate of refrigerant decreases toward the downstream side of the air, and the flow rate of refrigerant introduced into the refrigerant passage increases on the upstream side of the air compared to the downstream side of the air.

However, multiple louvers are installed inside the refrigerant distribution pipe not only on the air upstream side, but also from the upstream side to the downstream side, so that extreme refrigerant flow rates can occur between the air upstream side and the downstream side of the multiple refrigerant passages. (The refrigerant flow rate decreases smoothly from the upstream side to the downstream side. Therefore, the refrigerant flow rate is supplied to each refrigerant passage according to the air heat load, and the refrigerant evaporates uniformly. is obtained.

(Effects of the Invention) Therefore, according to the present invention, compared to the conventional method, only the inlet vibrator can be handled more easily, and the efficiency of piping work can be improved. In addition, since the inlet vibrator can be easily handled, the case in which the refrigerant evaporator is installed can be made smaller, which improves the ease of installation. Further, since the refrigerant is uniformly evaporated within each refrigerant passage, there is an effect that the air cooling efficiency of the refrigerant evaporator is improved.

(Example) The present invention will be explained in detail below with reference to embodiments shown in the drawings.

FIG. 9 shows the overall configuration of the refrigerant evaporator of the present invention, and as can be seen from the comparison with the conventional example shown in FIG.
The refrigerant collecting pipe 2 is connected to the refrigerant collecting pipe 2 by brazing. Inside this refrigerant collecting pipe 2, as shown in FIG. 1 which is a first embodiment of the present invention, a guide plate 1 made of a metal with good heat conduction such as aluminum having a plurality of louvers 10a is installed.
0 is set.

The configuration of the first embodiment will be explained in detail below. The number of refrigerant passages formed inside the flat tube 1 is approximately 26 in order to maximize the heat transfer area of the refrigerant when the width of the flat tube 1 is approximately 105 mm. The number of louvers 10a provided is preferably 7 to 8.

According to the present inventors, the reason is considered to be as follows. In other words, if the number of louvers 10a is too small, the difference in the amount of refrigerant flowing into the upstream refrigerant passage 1a and the downstream refrigerant passage becomes extremely large, making it impossible to uniformly evaporate the refrigerant. This is because if the number of 10a is too large, the resistance when the refrigerant flows becomes large and the pressure loss increases.

The louver 10a is easily formed by punching or pressing a guide plate.

In this case, for ease of processing, a louver 10 is used as shown in Fig. 2.
Eight portions 10b are formed at the tip of a.

As shown in FIG. 1, this louver 10a is formed so as to form a constant angle θ (for example, 20±5°) with respect to the inflow direction of the refrigerant. In this case, the angle θ of the louver 10a is set to 2
The reason why the angle θ is set to 0±5° is that if the angle θ is too large, the pressure loss increases, and if the angle θ is too small, the effect of changing the flow of the refrigerant in the direction of the refrigerant passage 1a is small.

A plan in which a plurality of louvers 10a are formed as described above.
After the IX inner plate 10 is installed in the refrigerant distribution pipe 2 whose inner and outer surfaces are clad with brazing material, the flat tube 1. Heat transfer fins 3. Refrigerant distribution pipe 2. Together with the refrigerant manifold pipe 4, it is integrally brazed in a furnace. Therefore, both sides 10A and IOB of the guide plate 10 are brazed to the inner surface of the refrigerant distribution pipe 2, as shown in FIG.

Next, the operation of this embodiment having the above configuration will be explained.

The refrigerant expanded under reduced pressure by the expansion valve 7 is introduced into the refrigerant distribution pipe 2 from the introduction pipe 2a side of the refrigerant distribution pipe 2 as shown by the arrow in FIG. 1 through the inlet vibrator 5 in a gas-liquid mixed state. Ru.

Here, the refrigerant passage 1a is formed in a direction perpendicular to the flow of refrigerant flowing inside the refrigerant distribution pipe 2, but the louver 1a
Since 0a is inclined at an angle of θ with respect to the flow of the refrigerant, the refrigerant introduced into the refrigerant distribution pipe 2 is transferred to the refrigerant passages 1 provided in multiple rows within the flat tube 1 by the louver 10a.
Of the air a, the air is sequentially introduced into the refrigerant passage from the upstream side to the downstream side. In this case, the refrigerant upstream side 2a of the refrigerant distribution pipe 2 (
Since the amount of refrigerant on the air upstream side A) is larger than that on the downstream side, the louver 10a in the refrigerant passage located on the air most upstream side
A large amount of refrigerant flows in as shown by the arrow, and the remaining refrigerant is similarly sequentially introduced into the refrigerant passage la on the downstream side of this refrigerant passage 1a. Therefore, the flow rate of refrigerant decreases toward the downstream side of the air, and the flow rate of refrigerant introduced into the refrigerant passage increases on the upstream side of the air compared to the downstream side of the air.

Moreover, since a plurality of louvers 10a are provided inside the refrigerant distribution pipe 2 not only on the air upstream side but also from the upstream side to the downstream side, there are extreme There is no change in the refrigerant flow rate, and the refrigerant flow rate decreases smoothly from the upstream side to the downstream side. Therefore, a refrigerant flow rate corresponding to the air heat load is supplied to each refrigerant passage la, and uniform refrigerant evaporation is obtained.

As described above, according to this embodiment, a large amount of refrigerant can be introduced into the refrigerant passage on the air upstream side without piping the inlet vibrator 5 to the air downstream side B.

Moreover, according to the first embodiment, as shown in FIG. 9, the inlet pipe 5 is hardly located in the air passage cooled by the refrigerant evaporator, so that the ventilation resistance can be reduced. In addition, since high-temperature and high-pressure refrigerant flows inside the high-pressure side pipe 9 on the upstream side of the expansion valve 8, if this part is located in the air passage as shown in FIG. Although this is undesirable as it increases the heat load, in this embodiment, since this portion is not located in the air passage, it also has the effect of reducing the heat load.

Next, other embodiments of the present invention will be described.

4 and 5 show a second embodiment, in which a guide plate 10
, the auxiliary louver 10d is installed in the opposite direction to the louver 10a.
is provided by punching, pressing, etc. By providing this auxiliary louver 10d, the refrigerant introduced into the refrigerant distribution pipe is more smoothly introduced into the refrigerant passage. Also,
The open end of the flat tube 1 is protruded by a length t inside the refrigerant distribution pipe 2 in order to ensure joint strength during brazing and to appropriately distribute the refrigerant to each refrigerant passage 1a. However, since the auxiliary louver 10d is formed on the guide plate 10, this amount of protrusion can be appropriately controlled.

Next, a third embodiment of the present invention will be described. One of the methods for forming the refrigerant passage 1a in the flat tube 1 is by extrusion molding.
A partition wall 1b is formed between them, as shown in FIG. Therefore, if the flat tube 1 is cut so as to leave the partition walls 1b every few partitions, the tip of the flat tube 1 will have a plurality of partition walls (7 in this third embodiment) as shown in FIG. Partition wall 1b of 1) is in a protruding state. If this partition wall 1b is bent by a certain angle θ (for example, 20±5°) as shown in FIG. 8, these partition walls 1d
However, the flow of the refrigerant can be changed similarly to the louver 10a of the first and second embodiments.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing the first embodiment of the present invention;
The figure is a plan view of a guide plate according to the first embodiment of the present invention.
6. FIG. 3 is a view taken in the direction of arrow E in FIG. 1, FIG. 4 is a schematic sectional view showing the second embodiment of the present invention, and FIG. 6 is a plan view of the tip of the flat tube, FIGS. 7 and 8 are plan views showing a third embodiment of the present invention, FIG. 9 is a perspective view of an evaporator to which the present invention is applied, and FIG. 10 is a perspective view of a conventional evaporator. 1... Flat tube, 1a... Refrigerant passage, 2...
Refrigerant distribution pipe, 3... Heat transfer fin, 4... Refrigerant collecting pipe, 5... Inlet vibe, 6... Outlet vibe, 7...
Expansion valve, 8... Temperature sensing cylinder, 9... High pressure side pipe, 10
...information board, 10a...louver.

Claims (1)

[Claims] A flat tube having a plurality of refrigerant passages, a heat transfer fin joined to the tube in a heat conductive manner, and a refrigerant introduction end located on the air upstream side of the flat tube and the heat transfer fin. a refrigerant distribution pipe whose longitudinal portion is joined to the refrigerant inflow opening end of the flat tube and distributes refrigerant to the refrigerant passage; and a plurality of refrigerant distribution pipes provided inside the refrigerant distribution pipe in the longitudinal direction from the refrigerant introduction end A refrigerant evaporator comprising: a louver that guides refrigerant to the refrigerant passage side.