JP2636399B2 - Heat exchanger - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, and more particularly to a header type heat exchanger used efficiently as a condenser in an air conditioning cycle.

[Prior Art] Header type heat exchangers have attracted attention because they are easy to manufacture and have good heat exchange efficiency (for example, JP-A-63-34466), and the schematic structure is shown in FIG.

In the figure, a large-diameter tubular header 1A provided at the left and right positions,
1B, small-diameter tubes 2 are vertically arranged in parallel with both ends connected to these opposing side walls.
The corrugated fins 3 are provided between them. The above header
The inside of 1A is vertically partitioned, and a gaseous refrigerant is supplied to the upper chamber 1a from a refrigerant input 11 provided at the upper end. The supplied gaseous refrigerant flows through the tube 2 connecting the upper chamber 1a and the header 1B, and is cooled during this time to reach the header 1B. The gaseous refrigerant flows downward in the header 1B, and reaches the lower chamber 1b of the header 1A via another tube 2. During this time, the entire gas refrigerant is cooled and condensed into a liquid refrigerant, and is sent out from a refrigerant outlet 12 provided at the lower end.

[Problems to be Solved by the Invention] By the way, a part of the gas refrigerant is condensed and liquefied in the tube 2 from the header 1A to the header 1B, and falls down in the header 1B together with the gas refrigerant. Depending on the condition of the refrigerant outlet side, the liquid may accumulate at the bottom of the header to increase the liquid level (L in FIG. 8), and the lower end and the inside of the tube 2 near the lower end may be filled with the liquid refrigerant. When such a state occurs, the gas refrigerant cannot flow through the tube 2 filled with the liquid refrigerant, and the number of tubes contributing to heat exchange is reduced, resulting in a decrease in heat exchange efficiency.

An object of the present invention is to provide a heat exchanger capable of effectively preventing a rise in the liquid level of a liquid refrigerant accumulated at the header bottom and avoiding a decrease in heat exchange efficiency.

[Means for Solving the Problems] The configuration of the present invention will be described with reference to FIG. 1. A plurality of tubes are connected between the headers 1A and 1B erected at the left and right positions by connecting both ends to the side walls of the headers 1A and 1B. 2 are arranged in parallel in the vertical direction, and radiation fins 3 are provided between the tubes 2 so that the gas supplied from the refrigerant inlet 11 provided in one of the headers 1A and 1B and flowing through the tubes 2 The heat exchanger that condenses the refrigerant into a liquid and sends it out from the refrigerant outlet 12 provided in any of the headers 1A and 1B is a heat exchanger.
1B is characterized in that the gaseous refrigerant is blown upward from below in at least the lower half of the header 1A in which the refrigerant outlet 12 is not provided.

[Operation] In the heat exchanger having the above configuration, the gaseous refrigerant blows upward from below at least in the lower end portion of the header 1B where the refrigerant outlet 12 is not provided. Thus, the liquid refrigerant accumulated at the bottom in the header 1B is blown up together with the gas refrigerant and does not increase the liquid level. Thus, there is no problem that the liquid refrigerant enters and closes the lower end and the tube 2 near the lower end, and the heat exchange efficiency is kept good.

First Embodiment In FIG. 1, a large-diameter cylindrical header 1A is provided at the left and right positions.
A number of small-diameter tubes 2 are provided in the vertical direction by connecting the opposed side walls of the headers 1A and 1B. Each tube 2 is arranged in parallel, and a corrugated heat radiation fin 3 is provided between them.

The inside of the header 1A is vertically divided by a partition wall 13 provided slightly below the center, and a refrigerant inlet 11 is provided at an upper end of the header 1A and a refrigerant outlet 12 is provided at a lower end. On the other hand, a partition wall 14 is provided inside the header 1B at a position corresponding to the partition wall 13, and a circular cylindrical portion 15 protruding downward is formed at the center of the partition wall 14 (FIG. 2). , FIG. 3), the tip of which extends downward from the lowermost tube and reaches near the bottom wall of the header 1B.

In the heat exchanger having the above structure, the gaseous refrigerant flowing from the refrigerant inlet 11 reaches the upper chamber 1c of the header 1B from the upper chamber 1a of the header 1A via the tube 2 and changes its direction downward to pass through the inside of the cylindrical portion 15. It circulates, changes its direction and hits the header bottom wall and blows up (arrows in FIGS. 1 and 2). The blown-up gas refrigerant flows through the tubes 2 through the openings of the tubes 2 connected to the lower chamber 1d, and flows into the lower chamber 1b of the header 1A.
And is discharged from the refrigerant outlet 12.

While flowing through the tube 2 from the header 1A to the header 1B, the gaseous refrigerant exchanges heat with the air flowing through the radiating fins 3 to partially condense and liquefy. The liquid refrigerant drops in the header 1B together with the gas refrigerant and accumulates at the bottom of the header.
In FIG. 2 and FIG. 2, L), the gas refrigerant changes direction upward and blows up, so that the gas refrigerant mixes with the gas refrigerant and is wound up. As a result, the refrigerant level at the bottom of the header does not rise. Absent.

The gaseous refrigerant mixed with the liquid refrigerant is blown up and circulates in the tube 2 from the header 1B to the header 1A, and the entire amount is condensed and liquefied by heat exchange during this time.

However, according to the heat exchanger having the above structure, the rise of the refrigerant liquid level is suppressed, so that the liquid refrigerant does not flow into the tube at the lower position, fills the tube, and does not block. The tube contributes to heat exchange, and efficient heat exchange is performed.

This effect is shown in FIG. The line x in the figure is the present invention, and the line y is a conventional example. As is known from the figure, the present invention is excellent in heat radiation performance, which is the amount of heat radiation per unit time, and this is more remarkable as the front wind speed flowing into the heat exchanger is higher.

[Second embodiment] When the refrigerant inlet 11 can be provided at the lower end of the header, the structure of the heat exchanger moves the partition 13 in the header 1A slightly upward from the center as shown in FIG. At least, it is only necessary to secure the number of tubes through which the high-temperature gaseous refrigerant flows.

In the figure, the gaseous refrigerant flowing into the lower chamber 1b of the header 1A reaches the header 1B via the tube 2, and blows up the inside of the header 1B (arrow in the figure). A part of the gaseous refrigerant is liquefied while flowing through the tube 2, but this liquid refrigerant is wound up in the header 1B together with the gaseous refrigerant, and as a result, the rise of the refrigerant level at the header bottom is suppressed. The entire amount of the gaseous refrigerant including the liquid refrigerant is liquefied in the tube 2 from the header 1B to the header 1A, reaches the upper chamber 1a of the header 1A, and is sent out from the refrigerant outlet 12 at the upper end of the header.

With such a structure, the same effect as in the above embodiment can be obtained.

[Third Embodiment] When the installation of the refrigerant inlet and the refrigerant outlet is possible only on the side of the header, the structure shown in Fig. 6 can be adopted. That is, the refrigerant inlet 11 is opened in the side wall of the header 1A, and the refrigerant outlet 12 is formed by joining a plurality of tubes 2 at the center position and drawing out to the side of the header 1A.

The gaseous refrigerant flowing into the header 1A from the refrigerant inlet 11 is separated into upper and lower parts, flows through the tubes 2 at the upper and lower positions, and reaches the header 1B. Thus, the gas refrigerant flows downward toward the tube 2 at the center position in the upper half of the header 1B, but flows upward toward the tube 2 in the lower half (arrow in the figure), and flows downward in the header bottom. The liquid refrigerant that accumulates in the water is wound up by the upward flow, and the rise of the liquid level is prevented.

According to this embodiment, the same effects as those of the above embodiments can be obtained.

[Effects of the Invention] As described above, the heat exchanger of the present invention has a structure in which the gas refrigerant blows up at least the lower half of the header having no refrigerant outlet, so that the liquid level of the liquid refrigerant accumulated at the bottom of the header rises. Thus, by eliminating the blockage of the tube by the liquid refrigerant, efficient heat exchange is enabled.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 4 show a first embodiment of the present invention.
FIG. 2 is an overall schematic sectional view of the heat exchanger, FIG. 2 is an enlarged sectional view of the lower half of the header, FIG. 3 is a perspective view thereof, FIG. 4 is a graph showing a heat radiation effect, and FIG. FIG. 6 is an overall schematic cross-sectional view of a heat exchanger showing a second embodiment, FIG. 6 is an overall schematic cross-sectional view of a heat exchanger showing a third embodiment of the present invention, FIG. 7 and FIG. FIG. 7 is an overall schematic sectional view of the heat exchanger, and FIG. 8 is an enlarged sectional view of the lower half of the header. 1A, 1B Header 11 Refrigerant inlet 12 Refrigerant outlet 13, 14 Partition wall 15 Tube section 2 Tube 3 Radiation fins

Claims (1)

(57) [Claims] 1. A plurality of tubes are installed in parallel in the vertical direction by connecting both ends to the side wall of each header between headers erected at the left and right positions, and a radiation fin is provided between the tubes. In the heat exchanger supplied from the refrigerant inlet provided in any of the above, the gas refrigerant flowing through each of the tubes is condensed into a liquid, and is sent out from the refrigerant outlet provided in any of the headers. A heat exchanger characterized in that a gas refrigerant is blown upward from below at least in a lower half of a header having no refrigerant outlet.