JPH042380Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention is used in an air conditioner for automobiles,
This invention relates to a serpentine capacitor for automobiles that is installed at the front of the engine room.

(Prior Art) An air conditioner for an automobile is equipped with a cooling cycle for the purpose of cooling the interior of the vehicle. The cooling cycle requires a condenser to condense the gaseous refrigerant that has become high temperature and high pressure in the compressor.

As shown in FIG. 4, in the case of an automobile, this capacitor 1 is mounted on the front of a radiator 3 at the forefront of an engine room 2. The condenser 1 and the radiator 3 are connected to the running wind from the lower gap 6 of the grille 4 or bumper 5, or to the engine 7.
It is designed to be cooled by suction air from a fan 8 which is rotationally driven by a fan 8.

As a capacitor 1 installed in a car,
As shown in FIG. 5, a serpentine type is used in which fins 10 are interposed between flat tubes 9 bent in a serpentine shape to form an air circulation space 20. In particular, recently, in order to reduce the flow resistance of the refrigerant, the flow path from the inlet pipe 11 is divided into two to form an upper heat exchange section 12 and a lower heat exchange section 13, and these are joined at the outlet pipe 14. so-called 2
Pass-type serpentine capacitors are often used.

(Problem to be Solved by the Invention) However, in the case of such a two-pass serpentine condenser 1, the vertical flow path length X of the upper heat exchange section 12 and the vertical direction of the lower heat exchange section 13 It has been found that the ratio to the flow path length Y greatly affects the performance of the capacitor (Japanese Patent Application Laid-open No. 57-187571).
(see publication). However, the ratio of flow path lengths that produces optimal performance also changes depending on the distribution of the wind acting on the capacitor, and with this in mind, a two-pass type that takes into account the ratio of flow path lengths is used. There were no serpentine capacitors.

In particular, in recent years, in order to reduce the ventilation resistance when the car is running, the use of slant noses (lowering the vehicle height at the tip of the bonnet 15, as shown in Figure 4) has progressed, and the opening area of the grille 4 has increased. As the capacitor 1 has become smaller, the distribution of airflow acting on the capacitor 1 has become different from that in the past, and a two-pass serpentine capacitor corresponding to this has become necessary.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a two-pass serpentine capacitor for automobiles that has optimal performance in accordance with the recent trend toward slant noses.

(Means for Solving the Problems) In order to achieve the above object, the present invention is a flat structure that is installed in the frontmost part of the engine room of an automobile, where the amount of air passing through is different at the upper and lower parts, and through which the refrigerant flows. Compared to the flow path in the upper heat exchange section where the tubes are bent in a serpentine shape to form an air circulation space between each tube, and the flow path is installed in a part where a relatively small amount of air passes through from one inlet tube through each tube. In a two-pass type serpentine condenser for automobiles, in which the refrigerant that has passed through the flow paths in the lower heat exchanger section installed at a portion with a large amount of passing air flows out from one outlet pipe, the lower heat exchanger section The serpentine condenser for automobiles is characterized in that the length of the flow path is shorter than the length of the flow path of the upper heat exchange section.

(Function) When the two-pass type serpentine capacitor for automobiles having such a configuration is installed in the frontmost part of the engine room of a car with a slant nose, it is possible to reduce the amount of wind that enters into the engine room from the grille when the car is running. Since more air flows in from the lower part of the bumper, the amount of air hitting the lower heat exchange section is greater. Since the length of the flow path in the lower heat exchange section is shorter than the length of the flow path in the upper heat exchange section, the flow resistance of the refrigerant is lower in the lower heat exchange section, and a relatively large amount of refrigerant flows in the lower heat exchange section. Therefore, even if the heat transfer area of the lower heat exchange section is somewhat smaller than that of the upper heat exchange section, the flow rate of refrigerant is larger, so that the lower heat exchange section can exchange a larger amount of heat. Moreover,
By making the vertical passage length of the lower heat exchange section, which has a high heat exchange capacity, relatively short, the flow resistance of the refrigerant is lowered and the refrigerant flow rate is increased, allowing a large amount of refrigerant to be heat exchanged. Therefore, the heat exchange capacity as a whole is improved.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

Fig. 1 is a front view of a two-pass serpentine capacitor for automobiles showing an embodiment of the present invention, Fig. 2 is a schematic diagram illustrating the operation of the embodiment, and Fig. 3 is a diagram explaining the operation of the embodiment. It is a graph, and the fourth and fifth
Components common to those shown in the figures are given the same reference numerals.

As shown in FIG. 1, the capacitor 1a according to this embodiment has a flat tube 9 bent in a meandering shape.
This is a serpentine type capacitor in which a fin 10 is interposed between each tube 9 and an air circulation space 20 is formed. Moreover, this capacitor 1a is
The flow path from the inlet pipe 11 is divided into two to create an upper heat exchange section 1.
This is a two-pass type condenser in which a lower heat exchanger 2a and a lower heat exchanger 13a are formed, and these are joined at an outlet pipe 14.

Particularly in this embodiment, the upper heat exchange section 12a
The lower heat exchange section 13 for the vertical flow path length X of
The ratio Y/X of the vertical flow path length Y of a is set to 0.8 to 1.0. This is because the location where the two-pass serpentine capacitor 1a is installed is considered. That is, in the case of the condenser 1a installed at the frontmost part of the engine room in a car with a slant nose, the air volume hitting the lower heat exchange part 13a is larger than the air volume hitting the upper heat exchange part 12a, so this is used. This is to maximize the overall amount of heat exchange.

Lower heat exchange section 13 for upper heat exchange section 12a
As shown in Figure 3, it has been confirmed through experiments that the heat exchange amount of the entire condenser is maximized when the ratio Y/X of the vertical flow path length of a is 0.8 to 1.0. The reason may be as follows.
As shown in FIG. 2, the amount of air hitting the upper heat exchange section 12a is smaller than the amount of air hitting the lower heat exchange section 13a. Therefore, in order to increase the overall heat exchange amount,
Lower heat exchange section 1 with large air volume and sufficient cooling capacity
A relatively large amount of refrigerant may be allowed to flow through 3a. To flow a large amount of refrigerant without changing the size of tube 9,
The flow resistance may be reduced by reducing the length of the flow path of the tube 9, that is, the length Y of the flow path in the vertical direction. It is thought that this allows a relatively large amount of refrigerant to flow into the lower heat exchange section 13a, thereby increasing the amount of heat exchange there. However, if the channel length is too short, the heat exchange area becomes small, and even if the air volume and refrigerant flow rate are large, the amount of heat exchange ends up decreasing. Therefore, if these are considered, there exists an optimum value for the flow path length ratio Y/X that maximizes the amount of heat exchange, and that value is Y/X=0.8 to 1.0.

(Effects of the invention) As explained above, according to the invention, the length of the flow path in the lower heat exchanger section is made shorter than the length of the flow path in the upper heat exchanger section. This has the excellent effect of achieving optimal heat exchange performance.

[Brief explanation of drawings]

Fig. 1 is a front view of a two-pass serpentine capacitor for automobiles showing an embodiment of the present invention, Fig. 2 is a schematic diagram illustrating the operation of the embodiment, and Fig. 3 is a diagram explaining the operation of the embodiment. 4 is a schematic sectional view of the main parts of an automobile showing the position where the capacitor is installed, and FIG. 5 is a front view of a conventional two-pass serpentine capacitor H for an automobile. 1, 1a...Condenser, 2...Engine room, 4...Grill, 5...Bumper, 9...Tube, 11...Inlet pipe, 12, 12a...Upper heat exchange section, 13, 13a...Lower Heat exchange section, 14...
...Exit pipe, 20...Air circulation space, X, Y...Vertical flow path length.

Claims (1)

[Scope of utility model registration request] The flat tubes 9, which are installed in the frontmost part of the engine room of an automobile at positions where the amount of air passing through differs between the upper and lower parts, and through which the refrigerant flows inside, are bent in a meandering manner to form air circulation spaces 20 between each tube. ,
A flow path in the upper heat exchange section 12a that passes through each tube from one inlet pipe 11 and is attached to a portion where a relatively small amount of air passes through, and a lower heat exchange section 13 that is attached to a section where a relatively large amount of air passes through.
In a two-pass serpentine condenser for automobiles, the refrigerant that has passed through the flow paths in a and 14a flows out from one outlet pipe 14a,
A serpentine condenser for an automobile, characterized in that the passage length of the lower heat exchange section 13a is shorter than the passage length of the upper heat exchange section 12a.