JPS61191889A - Heat exchanger - Google Patents

Abstract

PURPOSE:To improve heat exchanging performance by a method wherein a flat pipe is provided with recessed grooves at the central section thereof and is equipped with an inlet header, an outlet header and a communicating header. CONSTITUTION:The heat exchanger is formed by bending the flat pipe 7 and the inlet header 3 as well as the outlet header 4 are connected to one end thereof while the communicating header 6 is connected to the other end thereof and corrugated fins 2 are brazed integrally with the bent flat pipe. Refrigerant enters through the inlet header 3, flows through the fat pipe 7 at the downstream side 7' of airflow and enters into the communicating header 6 under being evaporated. The refrigerant flows through respective small refrigerant paths 5, the refrigerant, having ununiform gas/liquid ratio is mixed in the communicating header 6 and is uniformed, then, flows through respective small refrigerant paths 5 at the upstream side 7'' of the airflow to the outlet header 4 and, thereafter, flows out as refrigerant gas having proper superheated degree. One part of condensed water flows along the corrugated fins 2 and the other part of the same flows through the recessed grooves 8 of the flat pipe 7, thereafter, is discharged. Thus, a return trip circuit may be formed by one piece of flat pipe 7, the gas/liquid ratio of the refrigerant may be uniformed and the condensed water may be discharged smoothly, therefore, the heat exchanging performance may be improved.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an air conditioning heat exchanger.

Conventional technology In recent years, there has been a desire for indoor heat exchangers for automotive cooling systems to be lightweight and space-saving, and for this reason, corrugated fins are used as the air side fins, and all-aluminum heat exchangers are integrally brazed with flat tubes. The vessel is known.

An example of the conventional heat exchanger mentioned above will be described below with reference to the drawings.

FIG. 4 shows a conventional heat exchanger. In FIG. 4, reference numeral 1 indicates an extruded flat tube serving as a refrigerant passage. 2 is a corrugated fin formed from a plating sheet material with brazing material clad on both sides. 3 is the inlet side header where refrigerant enters and exits from the ladder to the outlet side of 4. The flat tube 1 is bent into a meandering shape, with corrugated fins 2 interposed therebetween, and integrally joined by furnace brazing material.

The inlet header 3 and the outlet header 4 are also joined to the flat tube 1 at the same time.

FIG. 5 is a cross section of a flat tube of a conventional heat exchanger.

It is separated by a plurality of walls, and a small refrigerant passage 6 is formed.

FIG. 6 shows a state in which condensed water 6 condensed due to latent heat exchange accumulates in the corrugated fin 2 portion.

The refrigerant passes through the inlet header 3, evaporates from liquid in the flat tube 1, becomes gas, and exits from the outlet header 4. Air flows in the direction of the arrow, is cooled by the refrigerant, and air moisture is condensed by latent heat exchange. The condensed water flows downward along the corrugated fins, but some of it accumulates at the base of the corrugated fins 2, as shown in FIG.

Problems to be Solved by the Invention However, there are two major problems with the above configuration. First, the refrigerant is evenly distributed and flows from the inlet header 3 to the refrigerant passage 6 of the flat tube 1, but the heat load (heat exchange amount) of each refrigerant passage 6 is large on the windward side, and On the outlet header 4 side of the flat tube 1, for each small refrigerant passage (
The problem was that the (gas/liquid) ratio was different, with overheated gas being present on the windward side and the (gas/liquid) ratio being large on the leeward side, resulting in the heat exchanger not being fully utilized.

Second, as shown in Figure 6, condensed water accumulated, blocking the air passage, reducing the amount of inflowing air, and lowering the heat exchange performance. Furthermore, the temperature of the refrigerant in the heat exchanger is lowered, which tends to accelerate the freezing of condensed water.

In view of the above-mentioned problems, the present invention aims, firstly, to equalize the (gas/liquid) ratio on the windward side and the leeward side in the small refrigerant passage 6, and secondly, to improve the draining performance of condensed water. The purpose of this is to improve heat exchange performance.

Means for Solving the Problems In order to solve the above problems, the heat exchanger of the present invention provides a concave groove in the center of the flat tube over the entire length of the flat tube, and also connects an inlet header, an outlet header, and a connecting ladder. It has the following configuration.

Effect: With the above configuration, the present invention allows refrigerant to enter from the inlet header on the leeward side, pass through the flat tube, be mixed at the connecting header, enter the flat tube on the outward path again, and exit from the ladder to the outlet on the windward side. As a result, the (gas/liquid) ratio is equalized in the connecting header. In addition, the condensed water flows down smoothly through the flat pipe groove, preventing condensed water from accumulating.

EXAMPLE Hereinafter, a heat exchanger according to an example of the present invention will be described with reference to the drawings.

1 to 3 show a heat exchanger in an embodiment of the present invention. In the figure, 6 is a connecting header, and 7 is a flat tube, which has a concave groove 8 over its entire length on both sides of the center portion.

In the heat exchanger, a flat tube 7 having a cross section as shown in FIG. 2 is first bent and formed, and one end is notched as shown in FIG. 3.

An inlet header 3 and an outlet header 4 are joined to one notched end, and a communication header 6 is joined to the other end, which are integrally brazed together with the corrugated fins 2.

The operation will be explained below using FIG.

The refrigerant enters from the inlet header 3 and flows along the leeward side 7' of the flat tube 7, and the refrigerant liquid enters the connecting header 6 while evaporating. The refrigerants flowing through the small refrigerant passages 6 of the flat tubes 7 and having non-uniform (gas/liquid) ratios are mixed in the communication header 6. Once again, the refrigerant (gas/liquid) is homogenized, flows through each of the small refrigerant passages 6 on the windward side 7'', reaches the outlet header 4, and flows out as refrigerant gas with an appropriate degree of superheat.

Also, the air is cooled and air moisture is condensed due to latent heat exchange. A portion of the condensed water flows along the corrugated fins 2, and a portion flows through the concave grooves 8 of the flat tube 7, and is discharged.

As described above, according to this embodiment, the concave groove 8 of the flat tube 7 allows the inlet header 3 and the outlet header 4 to be located at the same end of the flat tube, and the connecting header is placed at the other end. 6 can be positioned, a reciprocating circuit can be formed with a single flat tube 7 for the refrigerant, and the (gas/liquid) ratio of the refrigerant can be made uniform.
Heat exchange performance is improved by making full use of the flat tubes 7. Moreover, on the other hand, the condensed water does not accumulate in the corrugated fin 2 portion and is smoothly discharged, and the heat exchange performance is improved due to the increase in the amount of incoming air.

Effects of the Invention As described above, the present invention greatly improves heat exchange performance by providing an inlet header and an outlet header at one end, a connecting header at the other end, and a flat tube with a concave groove. This makes it possible to achieve weight reduction and space savings. Further, problems such as freezing of condensed water can also be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a heat exchanger in an embodiment of the present invention;
Figure 2 is a sectional view of the flat tube of the heat exchanger, Figure 3 is a perspective view of the main part of the flat tube, Figure 4 is a perspective view of a conventional heat exchanger, and Figure 6 is the flat tube of Figure 4. A sectional view of the tube, FIG. 6 is an enlarged view of the main part of FIG. 4. 2... Corrugate fin, 3... Inlet side header, 4... Outlet side header, 6...
...Communication header, 7...Flat tube, 8...
...Concave groove. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 21. , corrugate fin 3... to the entrance, rig °- 4゛shirohezug °- 6... continuous, active hetsu °- 7... false flat surface... concave groove No. 2123 5... Rei 4 Kankodori J each 7... IA hand tube I... Concave groove Fig. 3 516. Tokoi Road 7...Kashi? -Pu1-r! 5ffS skin figure 4

Claims (1)

[Claims] A flat tube with a porous refrigerant passage formed inside is formed into a meandering shape, and an inlet header and an outlet header are installed at right angles to the refrigerant passage, and a connecting header is connected to the flat tube at the other end, so that the flat tubes are connected to each other. A corrugated fin is installed in between,
A heat exchanger characterized in that a concave groove is provided in the center portion of the flat tube over the entire length.