JPH10185360A - Condenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure stabilized cooling performance by a method wherein the tip end opening of an outlet tube in an upper side header pipe is positioned at a lower part than the upper end openings of heat transfer tubes, opened in the header pipe, in a condenser provided with a plurality of heat transfer tubes between a pair of upper and lower header pipes. SOLUTION: A condenser for a vapor compression type refrigerating machine is provided with a pair of upper and lower header pipes 6b, arranged in horizontal direction, a plurality of pieces of heat transfer tubes 7, whose upper and lower ends are opened in the header pipes 6b, and fins, provided between the header pipes while an outlet tube 13 is provided in the upper header pipe 6b. In this case, the upper end openings 15, 15 of respective heat transfer tubes 7, 7 are situated at the substantially central part of the up-and-down direction while the tip end opening 14a of the outlet tube 13a is situated in the lower half of the header pipe 6b. According to this method, liquid refrigerant can be sent into the outlet tube 13a even when the amount of liquid refrigerant, stayed in the header pipe 6b, is comparatively small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A condenser according to the present invention is incorporated in series between a compressor and an evaporator of a vapor compression refrigerator constituting an air conditioner for an automobile. Then, the refrigerant compressed by the compressor is radiated and condensed, and then sent out to the evaporator via the liquid tank.

[0002]

2. Description of the Related Art A vapor compression refrigerator is incorporated in an automotive air conditioner for cooling and dehumidifying the interior of an automobile.
FIG. 4 is a circuit diagram showing a basic configuration of a vapor compression refrigerator described in Japanese Patent Laid-Open No. 4-95522. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 exchanges heat with air while passing through the condenser 2 to lower the temperature and condense and liquefy. The resulting liquid refrigerant is once stored in the liquid tank 3, sent to the evaporator 5 via the expansion valve 4, and evaporates in the evaporator 5. Since the temperature of the evaporator 5 decreases due to the deprivation of latent heat of vaporization, the flow of air for air-conditioning through the evaporator 5 reduces the temperature of the air and simultaneously removes the water vapor contained in the air. Can be. The refrigerant evaporated and vaporized in the evaporator 5 is sucked by the compressor 1 and compressed, and the cycle is repeated again.

[0005] Next, FIG. 5 shows a capacitor 2 to which the present invention is applied. The condenser 2 is of a so-called vertical flow type, in which a refrigerant flows vertically between a pair of upper and lower header pipes 6a and 6b which are horizontally arranged at an interval vertically. Such a vertical flow type capacitor 2 has been studied in order to make the radiator compact by using a common fin with a radiator core (not shown) disposed close to the radiator. Each header pipe 6 constituting such a capacitor 2
One or more partition walls are provided inside each of the a and 6b, and the inside of each of the header pipes 6a and 6b is partitioned into a plurality of chambers while maintaining airtightness and liquid tightness. Further, a plurality of heat transfer tubes 7 constituting the core 9 of the condenser 2,
7 is between the pair of header pipes 6a and 6b,
Fins 8, between heat transfer tubes 7, 7 horizontally adjacent to each other,
8 are arranged in the up-down direction while sandwiching them. Also, a core portion 9 composed of each of the heat transfer tubes 7, 7 and the fins 8, 8
Side plates 10a,
10b is provided.

An inlet block 11 is brazed and fixed to the upper surface of one end (the right end in FIG. 5) of the upper header pipe 6b. The entrance block 11 is provided with an entrance port 12, which communicates with the inside of one end of the upper header pipe 6b. As shown by the arrow in FIG. 5, the refrigerant sent from the inlet port 12 flows while returning between the pair of header pipes 6a and 6b.

Further, an outlet pipe 13 is fixed to the other end (left end in FIG. 5) of the upper header pipe 6b on the upper surface of a portion corresponding to the chamber located at the most downstream side of the condenser 2. . The outlet pipe 13 is connected to the upper header pipe 6.
b. The refrigerant flowing into the condenser 2 and flowing through the condenser 2 as indicated by an arrow in FIG. 5 reaches the inside of the other end of the upper header pipe 6b. Then, this refrigerant is discharged from the outlet pipe 13 and sent to the evaporator 5 (see FIG. 4) through the liquid tank 3 and the expansion valve 4.

In the case of the capacitor 2 which has been conventionally considered,
As shown in FIG. 6, the outlet pipe 13 is inserted into the header pipe 6b through a connection hole 16 provided on the upper surface of the upper header pipe 6b, and opens to the upper space of the header pipe 6b. The outer peripheral surface of the outlet pipe 13 and the inner peripheral edge of the connection hole 16 are air-tightly and liquid-tightly joined by brazing. The upper end of the heat transfer tube 7 is inserted into the header pipe 6b through a connection hole 17 provided on the lower surface of the upper header pipe 6b. And the heat transfer tube 7
Of the upper header pipe 6b in the vertical direction. Therefore, as shown in FIG. 6, when the amount of the liquid refrigerant remaining in the upper header pipe 6b is small (at a high load), the liquid level 21 is changed to the outlet pipe 1.
The liquid level 22 when the liquid refrigerant does not reach the tip opening 14 of the third pipe 3 and the amount of the liquid refrigerant is large (at a low load) is equal to the tip opening 1 of the outlet pipe 13.
It reaches up to 4. Note that the term “high load” means that the difference between the set temperature of the vehicle air conditioner and the actual temperature inside the vehicle is large, and the refrigerant flowing through the vehicle air conditioner frequently circulates. Is a state in which the difference between the set temperature of the vehicle air conditioner and the actual temperature inside the vehicle is small, and the circulation of the refrigerant flowing in the vehicle air conditioner is small.

[0007]

In the above conventional structure, when a small amount of the liquid refrigerant stays in the upper header pipe 6b, the liquid level 21 of the refrigerant is higher than the opening 14 at the tip end of the outlet pipe 13. As a result, the liquid refrigerant does not flow into the outlet pipe 13. For this reason, the amount of the liquid refrigerant sent from the condenser 2 to the expansion valve 4 decreases, and the evaporator 5
The temperature of (FIG. 4) cannot be lowered, and the cooling capacity of the air conditioner for an automobile cannot be sufficiently exhibited.

On the other hand, the upper header pipe 6
When a large amount of the liquid refrigerant stays in b, the liquid level 22 reaches above the opening 14 at the end of the outlet pipe 13, and instead of eliminating the above-described inconvenience, the following problem occurs. That is, as a result of the liquid surface 22 being located above the upper end opening 15 of the heat transfer tube 7, the refrigerant that rises in the heat transfer tube 7 and flows into the upper header pipe 6 b is
The liquid refrigerant staying inside the pipe enters the header pipe 6b while being pushed away. Liquid refrigerant has a higher viscosity than refrigerant vapor, and has higher resistance to being pushed away. Accordingly, the resistance of the refrigerant from entering the upper header pipe 6b from the heat transfer tube 7 and thus the resistance of the condenser 2 increase. An increase in the resistance of the condenser 2 is not preferable because it leads to a decrease in the performance of the vapor compression refrigerator incorporating the condenser 2. The capacitor of the present invention has been invented in order to eliminate any of these disadvantages.

[0009]

According to the present invention, there is provided a capacitor comprising:
As with the previously considered conventional capacitors,
A pair of upper and lower header pipes, which are arranged in the horizontal direction at an interval in the vertical direction, and are provided between the pair of header pipes, and both upper and lower ends are opened inside the respective header pipes. The plurality of parallel heat transfer tubes, the fins provided between the heat transfer tubes adjacent in the horizontal direction, and the outlet pipe provided in the upper header pipe of the pair of header pipes. Prepare. In particular, in the condenser of the present invention, the tip opening of the outlet pipe present in the upper header pipe is located below the upper end opening of the heat transfer pipe.

Further, preferably, the outlet pipe is provided so as to vertically penetrate the upper surface of the upper header pipe, and at least one projecting piece provided at a lower end edge of an opening of the outlet pipe is provided. The leading edge is abutted on the bottom surface of the upper header pipe and between the heat transfer tubes adjacent to each other on the left and right.

[0011]

The condenser according to the present invention having the above-described structure has a configuration in which the opening at the end of the outlet pipe provided on the upper header pipe is located lower than the upper end opening of the heat transfer pipe adjacent in the horizontal direction. Even when the amount of the liquid refrigerant is relatively small, the opening of the distal end of the outlet pipe is located below the liquid surface.
For this reason, it is possible to feed the liquid refrigerant into the outlet pipe. The upper end openings of the plurality of heat transfer tubes always protrude above the liquid surface of the liquid refrigerant staying in the upper header pipe. For this reason, the accumulated liquid refrigerant does not become a resistance against the discharge from the plurality of heat transfer tubes into the upper header pipe, and the resistance of the condenser can be reduced. Furthermore, if the leading edge of the outlet pipe abuts against the bottom surface of the upper header pipe, the support rigidity of the outlet pipe with respect to this header pipe can be improved.

[0012]

1 and 2 show a first embodiment of the present invention. The basic configuration of the capacitor of this example is the same as that of the conventional structure shown in FIG. However, in the condenser of the present invention, the point of the positional relationship between the end opening 14a of the outlet pipe 13a provided in the upper header pipe 6b and the upper end opening 15 of the heat transfer tubes 7, 7 horizontally adjacent to each other is as follows. This is different from the conventional capacitor described above. Therefore, for the same parts as those of the conventional structure described above, overlapping illustration and description will be omitted or simplified, and the following description will focus on features of the present invention.

The upper end openings 15, 1 of the heat transfer tubes 7, 7 are provided.
5 is located substantially at the center in the vertical direction of the upper header pipe 6b, while the tip opening 14a of the outlet pipe 13a is located in the lower half of the header pipe 6b.
Therefore, the distal end opening 14a is connected to each of the heat transfer tubes 7, 7
Are present below the upper end openings 15, 15. Since the distal end opening 14a of the outlet pipe 13a is located in the lower half of the header pipe 6b, even when the amount of the liquid refrigerant remaining in the header pipe 6b is relatively small, the outlet 14a can be used. The tip opening 14a of the tube 13a is located below the liquid level 21. Therefore, even when the liquid refrigerant is relatively small, it is possible to feed the liquid refrigerant into the outlet pipe 13a. The upper end openings 15 of the plurality of heat transfer tubes 7 are always connected to the upper header pipe 6.
b protrudes above the liquid refrigerant that accumulates in b. For this reason, the refrigerant that has risen in the plurality of heat transfer tubes 7, 7 is always discharged into the refrigerant vapor in the header pipe 6b. In other words, the upper end openings 15, 1 of these heat transfer tubes 7, 7
5 does not discharge the refrigerant into the staying liquid refrigerant. Therefore, the accumulated liquid refrigerant does not become a resistance to the refrigerant discharged from the plurality of heat transfer tubes 7 into the header pipe 6b. Therefore, capacitor 2
Resistance can be kept low.

Further, it is possible to effectively prevent the lubricating oil mixed in the refrigerant and passing through the condenser 2 from remaining at the downstream end of the upper header pipe 6b. That is, in the refrigerant passing through the condenser 2, the compressor 1 (FIG. 4)
Lubricating oil for lubrication is mixed. In addition, the flow velocity of the refrigerant at the downstream end in the flow direction of the refrigerant in a part of the upper header pipe 6b is reduced due to a volume decrease due to condensation and liquefaction of the refrigerant. For this reason, in the case of the conventional structure shown in FIG. 6 described above, the lubricating oil that has reached the portion located at the downstream end is located near the bottom surface of the upper header pipe 6b based on the decrease in fluidity. It stays and becomes difficult to be discharged to the outlet pipe 13. On the other hand, in the case of the condenser of the present invention, since the lubricating oil that has reached the downstream end is efficiently sent into the outlet pipe 13a, the stagnation of the lubricating oil in this portion is reduced, and the vapor compression is performed. The circulation property of the lubricating oil in the cycle of the type refrigerator can be improved.

FIG. 3 shows a second embodiment of the present invention.
An example is shown. The condenser of the present example is configured in the same manner as the condenser of the first example described above, and is provided at the lower end edge of the distal end opening 14b of the outlet pipe 13b.
Are formed in a pair in the axial direction. Then, the tip edges 20, 20 of the protruding pieces 19, 19
At the bottom of the upper header pipe 6b between the heat transfer tubes 7, 7 adjacent to each other on the left and right sides (see FIG. 2), and the butted portion is brazed. The number of the protruding pieces 19 is not limited to two, and at least one is sufficient. In addition, a sufficient passage for passing the liquid refrigerant is provided between the lower end edge of the portion of the end opening 14b of the outlet pipe 13b deviating from the protruding pieces 19, 19 and the bottom surface of the upper header pipe 6b. Should be secured.

In the case of the present embodiment constructed as described above, the outlet pipe 13b is provided at the periphery of the connection hole 16 (see FIGS. 1 and 2) provided in the upper header pipe 6b, and at the bottom of the header pipe 6b. It is supported and fixed at two positions. For this reason, the mounting strength of the outlet pipe 13b is improved. Other configurations and operations are the same as those of the above-described first example, and duplicated illustration and description will be omitted.

[0017]

As described above, the condenser of the present invention is constructed and operated as described above, so that it is less affected by the amount of liquid refrigerant accumulated in the upper header pipe and exhibits stable cooling performance. It is possible to improve the performance of the automotive air conditioner by reducing the resistance.

[Brief description of the drawings]

FIG. 1 is a view showing a first example of an embodiment of the present invention and corresponding to an enlarged BB cross section of FIG. 5;

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an end perspective view of an outlet pipe used in a second example of the embodiment of the present invention.

FIG. 4 is a circuit diagram of a vapor compression refrigerator incorporating a condenser.

FIG. 5 is a schematic perspective view showing an example of a capacitor to which the present invention is applied.

FIG. 6 is a view similar to FIG. 1, showing a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Liquid tank 4 Expansion valve 5 Evaporator 6a, 6b Header pipe 7 Heat transfer tube 8 Fin 9 Core part 10a, 10b Side plate 11 Inlet block 12 Inlet port 13, 13a, 13b Outlet pipe 14, 14a, 14b Tip opening Part 15 Upper end opening 16 Connection hole 17 Connection hole 19 Protrusion piece 20 Tip part 21, 22 Liquid level

Claims (2)

[Claims] 1. A pair of upper and lower header pipes which are arranged in the horizontal direction at an interval in the vertical direction, respectively, and are provided between the pair of header pipes. A plurality of heat transfer tubes parallel to each other, which are opened inside the pipe, fins provided between heat transfer tubes adjacent in the horizontal direction, and provided on an upper header pipe of the pair of header pipes. Wherein the tip opening of the outlet tube present in the upper header pipe is located below the upper end opening of the heat transfer tube. 2. An outlet pipe is provided so as to vertically penetrate an upper surface of an upper header pipe, and a leading edge of at least one protruding piece provided at a lower edge of an opening of the outlet pipe is provided.
The capacitor according to claim 1, wherein the capacitor abuts on a bottom surface of the upper header pipe and between heat transfer tubes adjacent to each other on the left and right.