JPH11287575A - Brazing plate type heat-exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformalize the dispersion of refrigerant liquid and to improve performance by a method wherein a narrow mixing space is formed between a refrigerant inlet nozzle hole and a refrigerant passage, and after mixing of gas and liquid in the mixing space, the mixture is caused to flow in the refrigerant passage. SOLUTION: Mixing spaces 7 are annular comparatively narrow space and communicate with each other effected through a small hole 9 formed through a heat transfer plate 1. The outer peripheral edge of the mixing space 7 communicates with a refrigerant passage R through an annular narrow gap 8 extending throughout a whole periphery, and refrigerant liquid entering a refrigerant inlet nozzle 5 first enters the refrigerant inlet nozzle hole 5A and advances in the mixing space 7 through the gap 5b of the opening 5a part of the adjoining heat transfer plates 1. Since the sectional area of a small hole 9 is set to greater than the section area of the annular gap 8, air bubbles and liquid are mixed together in the whole mixing space. Thus air bubbles are made small and simultaneously uniformly dispersed in the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing plate type heat exchanger used as a refrigerant evaporator.

[0002]

2. Description of the Related Art As shown in FIGS. 2 to 4, a brazing plate type heat exchanger comprises a plurality of stacked heat transfer plates (1) sandwiched between a pair of end frames (2). It is constructed by permanently joining with materials.
As in the case of a normal plate heat exchanger, alternate fluid passages for high-temperature fluid and low-temperature fluid are formed between the heat transfer plates (1), and an inlet / outlet nozzle for a heat exchange medium is attached to the end frame (2). ing. By way of example, a hot fluid inlet nozzle (3) and an outlet nozzle (4), and a cold fluid inlet nozzle (5) and an outlet nozzle (6).

For example, when used as a refrigerant evaporator, water is supplied to a high-temperature fluid inlet nozzle (3) and a refrigerant is supplied to a low-temperature fluid inlet nozzle (5). The refrigerant evaporates by taking heat from the water flowing in the adjacent high-temperature fluid passage while flowing through the low-temperature fluid passage formed between the heat transfer plates (1), and the generated refrigerant vapor flows from the low-temperature fluid outlet nozzle (6). Taken out. The water deprived of heat by the refrigerant and cooled is discharged as cold water from the high-temperature fluid outlet nozzle (4).

When used as a condenser for refrigerant vapor, refrigerant vapor is supplied to the high-temperature fluid inlet nozzle (3) and cold water is supplied to the low-temperature fluid inlet nozzle (5). The refrigerant vapor condenses by applying heat to the cold water flowing in the adjacent low-temperature fluid passage while flowing through the high-temperature fluid passage, and the refrigerant in the liquid phase is taken out from the high-temperature fluid outlet nozzle (4). The water that has taken heat from the refrigerant and has raised the temperature is discharged from the low-temperature fluid outlet nozzle (6).

[0005]

In a conventional brazing plate type heat exchanger which is used as an evaporator for flowing a refrigerant from below to above, when a refrigerant liquid containing bubbles enters from a refrigerant inlet nozzle, bubbles are formed in an arbitrary refrigerant. The refrigerant tends to flow into the passage and exit from the refrigerant outlet nozzle. Therefore, there is a problem that the dispersion of the refrigerant liquid is not uniform between the refrigerant passages and the performance is reduced.

Accordingly, an object of the present invention is to improve the performance by making the distribution of the refrigerant liquid in the refrigerant passage uniform.

[0007]

According to the present invention, a narrow mixing space is provided between a refrigerant inlet nozzle hole and a refrigerant passage in a brazing plate type heat exchanger used as an evaporator for flowing a refrigerant from below to above. The gas-liquid is mixed in the mixing space and then flows into the refrigerant passage.

A specific configuration of the mixing space may be a plurality of annular spaces which are concentric with the coolant inlet nozzle holes and communicate with each other through small holes arranged in a ring.

It is preferable that a flow path from the mixing space to the refrigerant passage is narrowed so that the refrigerant liquid in the mixing space is uniformly dispersed and flows into the refrigerant passage.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments illustrated in the drawings will be described.

First, the overall configuration will be described taking heat exchange between a refrigerant and water as an example. As described above with reference to FIGS. 2 to 4, the brazing plate heat exchanger is configured such that a plurality of superposed heat transfer plates (1) are sandwiched between two end frames (2). It is constituted by being permanently joined by brazing or the like. The heat transfer plate (1) has openings (3a, 4a, 5) at four corners as shown in FIG.
a, 6a), and although not shown in the drawings, a heat transfer surface having a heat transfer performance enhanced by imparting irregularities of a herringbone shape or other appropriate pattern is provided. The periphery of the adjacent heat transfer plate (1) is joined in a watertight manner, and the coolant passages (R) and the water passages (W) are alternately formed between the opposed heat transfer surfaces. In adjacent heat transfer plates (1) forming a water passage (W) between them, annular gaps are formed at predetermined intervals around the openings (3a, 4a) and around the openings (5a, 6a). Are joined to each other in a watertight manner. In adjacent heat transfer plates (1) forming a refrigerant passage (R) between each other,
Annular clearances at predetermined intervals are formed around the openings (5a, 6a), and the periphery of the openings (3a, 4a) are joined to each other in a watertight manner.

As shown in FIG. 3, the openings (3a, 4a, 5a, 6a) of the heat transfer plate (1) are aligned, respectively.
Water inlet nozzle hole (not shown), water outlet nozzle hole (4
A), refrigerant inlet nozzle hole (5A), refrigerant outlet nozzle hole (
(Not shown). A water inlet nozzle (3), a water outlet nozzle (4), a coolant inlet nozzle (5), and a coolant outlet nozzle (6) are attached to the end frame (2) so as to correspond to these nozzle holes. The water passage (W) communicates with the water inlet nozzle hole at the upper end, and the water outlet nozzle hole (4
A). On the other hand, the refrigerant passage (R) communicates with the refrigerant inlet nozzle hole (5A) at the lower end and communicates with the refrigerant outlet nozzle hole at the upper end. Therefore, water is supplied to the water inlet nozzle (3)
Through the water inlet nozzle hole (3A) from there, disperses into the water passage (W), flows therethrough, and gives heat to the refrigerant flowing in the adjacent refrigerant passage (R) while flowing in the water passage (W). The cooled water flows out of the water outlet nozzle (4) through the water outlet nozzle hole (4A). The refrigerant entering from the refrigerant inlet nozzle (5) flows into the refrigerant passage (R) through the refrigerant inlet nozzle hole (5A), and the vapor generated in the refrigerant passage (R) passes through the refrigerant outlet nozzle hole and passes through the refrigerant outlet nozzle. Outflow to (6).

The flow of the heat exchange medium shown here is one example, and the present invention is not limited to this. For example, in some cases, the refrigerant is supplied from the nozzle (5) and taken out from the nozzle (3), and the water is supplied from the nozzle (6) and taken out from the nozzle (4).

Next, the embodiment shown in FIG. 1 will be described. FIG. 1 is a cross-sectional view of a refrigerant inlet nozzle (5).
Referring to (A), the coolant inlet nozzle (5) is aligned with the coolant inlet nozzle hole (5A), and the coolant inlet nozzle hole (5A) passes through the mixing space (7) and the annular clearance (8). And the refrigerant passage (R). As can be understood from FIG. 1B, which is a front view of the heat transfer plate (1) in the mixing space (7), the mixing space (7) is an annular relatively narrow space, and the heat transfer plate (1). Are communicated with each other through a small hole (9) penetrating therethrough. The outer peripheral edge of the mixing space (7) communicates with the refrigerant passage (R) through an annular narrow gap (8) extending over the entire circumference.

The refrigerant liquid entering from the refrigerant inlet nozzle (5) first enters the refrigerant inlet nozzle hole (5A), from which the gap (5a) between the adjacent openings (5a) of the heat transfer plate (1).
b) into the mixing space (7). The cross-sectional area of the small hole (9) is set to be sufficiently larger than the cross-sectional area of the annular clearance (8), so that the bubbles and the liquid are mixed in all the mixing spaces (7), and the bubbles become smaller and Is evenly dispersed. The refrigerant in which the bubbles and the liquid are mixed in the mixing space (7) in this way flows into each refrigerant passage (R) through the annular clearance (8).

[0016]

As described above, according to the present invention, a narrow mixing space is provided between a refrigerant inlet nozzle hole and a refrigerant passage in a brazing plate type heat exchanger used as an evaporator for flowing refrigerant from bottom to top. After the gas-liquid is mixed in the mixing space, the gas is caused to flow into the refrigerant passage, so that the bubbles that have caused the performance degradation are mixed with the liquid and changed into small bubbles, and the uniformity of the air to each refrigerant passage is reduced. A flow is created. Therefore, according to the present invention, it is possible to make the most of the original heat transfer surface.

[Brief description of the drawings]

FIG. 1A is a partial longitudinal sectional view showing an embodiment,
(B) is a partial front view of a mixing space portion of the heat transfer plate.

FIG. 2 is a perspective view of a brazing plate type heat exchanger.

FIG. 3 is a cross-sectional view of the brazing plate heat exchanger of FIG. 2 passing through a refrigerant inlet nozzle and a water outlet nozzle.

FIG. 4 is a front view of a heat transfer plate.

[Explanation of symbols]

 R refrigerant passage W water passage 1 heat transfer plate 2 end frame 3 water inlet nozzle 3a opening 4 water outlet nozzle 4A water outlet nozzle hole 4a opening 5 refrigerant inlet nozzle 5A refrigerant inlet nozzle hole 5a opening 5b gap 6 refrigerant outlet nozzle 6a opening 7 Mixing space 8 Annular clearance 9 Small hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Bando 4-2-14-1 Fushimi-cho, Chuo-ku, Osaka-shi, Osaka Inside Hisaka Works Co., Ltd. (72) Inventor Shoji Okumura 4 Fushimi-cho, Chuo-ku, Osaka-shi, Osaka 2-14 Chome Inside Hisaka Manufacturing Co., Ltd.

Claims (3)

[Claims] In a brazing plate heat exchanger used as an evaporator for flowing a refrigerant from below to above, a narrow mixing space is provided between a refrigerant inlet nozzle hole and a refrigerant passage, and gas-liquid is mixed in the mixing space. A brazing plate type heat exchanger, wherein the brazing plate heat exchanger is made to flow into a refrigerant passage. 2. The brazing plate type heat exchanger according to claim 1, wherein said mixing space is an annular space concentric with the nozzle hole and communicates through small holes arranged in an annular shape. 3. The brazing plate according to claim 1, wherein a flow path from the mixing space to the refrigerant passage is narrowed so that the refrigerant liquid in the mixing space is uniformly dispersed and flows into the refrigerant passage. Type heat exchanger.