JP2003254681A - Heat exchanger and absorption refrigerating machine using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and strong heat exchanger by forming a constant falling liquid film, and also to provide a compact and high performance absorption refrigerating machine using it. <P>SOLUTION: In this heat exchanger, heats are exchanged between in-pipe fluid flowing inside a heat exchanger pipe 3 and out-pipe fluid flowing outside the pipe. A plurality of the heat exchanger pipes 3 are arranged in a horizontal direction, and stacked in an upward and downward direction, so as to form a heat exchanger pipe unit 4. A plurality of the units 4 are arranged in a horizontal direction at predetermined intervals, and both ends of the pipe 3 are jointed with a pipe plate 2 or a header for in-pipe fluid. A plate-like fin 12 is installed at the bottom of the pipes 3 in a manner that it is almost brought into close contact with the top face of the pipe 3 arranged at a lower stage of the pipes 3. The outer surface of the pipe 3 had better to be applied with a hydrophilic treatment for improving wettability. In this absorption refrigerating machine, the heat exchanger is used for at least one facility of an evaporator, an absorber, a regenerator and condenser constituting the absorption refrigerating machine. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat exchanger,
In particular, it relates to a compact and high-performance falling-film heat exchanger and an absorption refrigerator using the same.

[0002]

2. Description of the Related Art Conventional heat exchangers for absorption refrigerators, particularly evaporators, absorbers, regenerators and condensers, have mainly been shell-and-tube type as falling-film heat exchangers. . This heat exchanger has become considerably compact due to the development of various high-performance heat transfer tubes, but in recent years, a plate heat exchanger has been proposed for further compactness and higher performance. However, the conventional plate heat exchanger has the following problems to be solved. The uneven part provided in the periphery of the thin plate and in the internal flow path,
Although they are joined by brazing, welding, or the like, if there is an incomplete portion in a portion of this joint, airtightness is poor and strength is insufficient, and it is difficult to secure reliability. It is difficult to form a thin and uniform falling film over the wide heat transfer surface. High cost compared to commercial heat transfer tubes. In addition, the refrigerant vapor flow velocity is considerably high in the absorption refrigerator, and the pressure loss due to this is a factor causing the performance of the absorption refrigerator to deteriorate.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, forms a uniform falling liquid film, and is an inexpensive and strong heat exchanger, and a compact and high-performance heat exchanger using the same. An object is to provide an absorption refrigerator.

[0004]

In order to solve the above problems, the present invention provides a heat exchanger for exchanging heat between an in-tube fluid flowing inside a heat transfer tube and an out-tube fluid flowing outside thereof. The heat transfer tubes are arranged in a horizontal direction, and a plurality of outer surfaces of the heat transfer tubes are vertically stacked at a predetermined interval to form a heat transfer tube unit. Both ends of the heat tube are joined to a tube plate or a header for a fluid in the tube, and plate fins are provided at a predetermined interval below the heat transfer tube so that an upper surface of the heat transfer tube installed in a lower stage of the heat transfer tube is almost in close contact with the heat transfer tube. It was decided. In the heat exchanger, the outer surface of the heat transfer tube is preferably subjected to a hydrophilic treatment for improving wettability.

Further, in the present invention, the above-mentioned heat exchanger is used for at least one of the evaporator, the absorber, the regenerator, and the condenser constituting the absorption refrigerating machine. It was an opportunity. In the absorption refrigerator of the present invention, the heat exchanger can be used as a condenser, or can be used as an evaporator by providing a refrigerant spraying device on the upper part of the heat transfer tube unit, and can also be used as a heat transfer tube unit. It can be used as an absorber or a regenerator by providing an absorbing solution spraying device on the upper part of the. Further, the absorption refrigerator of the present invention,
The heat exchanger, a refrigerant spraying device alternately provided on the upper part of the heat transfer tube unit, an absorbing solution spraying device, and a recovering device for separating and recovering either the refrigerant or the absorbing solution at the lower part,
Alternately used as an evaporator, an absorber, or the heat exchanger, for providing an absorbing solution spraying device every other row in the upper part of the heat transfer tube unit, for separating and recovering either the refrigerant or the absorbing solution in the lower part A recovery device may be provided and used as a regenerator and a condenser alternately.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a cross-sectional configuration diagram showing an example of the heat exchanger of the present invention. In FIG. 1, six heat transfer tube units 4 are arranged in a container composed of a shell 1 and tube plates 2 at both ends. FIG. 2 is a cross-sectional configuration diagram showing another example of the heat exchanger of the present invention, (a) is a front view, (b) is a side view,
(C) is a cross-sectional view taken along line XX of (a), and (d) is Y of (a).
FIG. FIG. 2A shows a state in which the heat transfer tube unit 4 in which five heat transfer tubes 3 are stacked is joined to the tube plates at both ends. The tube plate and the heat transfer tube may be fixed by any of tube expansion, welding and brazing. A liquid spraying device 5 is provided above the heat transfer tube unit 4 so that the liquid flows down to the outside of the heat transfer tube.

In FIG. 2B, pitches P1 and P2 are provided at the end of the heat transfer tube as spaces for fixing to the tube sheet 2.
Is provided. The pitches P1 and P2 can be arbitrarily determined according to the outer diameter of the heat transfer tube 3. In FIG. 2B, the heat transfer tube unit 4 including five and four heat transfer tubes 3 is three.
Individually arranged. Further, the heat transfer tubes are arranged in a staggered pattern, but of course they may be arranged in a grid pattern.
In the XX cross-sectional view of (a) of FIG. 2 (c), the heat transfer tube having the plate fins 12 at the lower part is intimately stacked on the upper surface of the lower heat transfer tube to form the heat transfer tube unit 4. . A state in which the refrigerant or the absorbing solution sprayed from the spraying device flows down to the outside of the heat transfer tube 3 is illustrated.

Normally, when the heat transfer tube 3 is joined to the tube plate,
The space for joining was indispensable, and this space has not been effectively utilized until now. According to the present invention, the plate-shaped fins 12 are provided in the lower portion of the heat transfer tube 3, the plate-shaped fins are utilized as a heat transfer element, and the liquid (refrigerant or absorbing solution) flowing down from the upper heat transfer tube 3 is reliably transferred to the lower stage. Can be guided to the heat transfer tube 3. However, the plate fins can be omitted in the lowermost heat transfer tube. The contact gap between the plate fin 12 and the upper surface of the heat transfer tube 3 is not particularly specified, but is preferably about 0 to 2 mm. The plate fin may be formed integrally with the heat transfer tube or may be formed independently. In order to enhance the wettability and spreadability of the heat transfer surface, it is preferable that the surface of the heat transfer tube be subjected to hydrophilic treatment. The hydrophilic treatment can be achieved by forming irregularities on the surface of the heat transfer tube by means of an oxide film, shot blasting, metal spraying, or the like. The end shape of the heat transfer tube 3 is, as shown in FIG.
The plate fin 12 is provided in the central portion of the heat transfer tube 3 and is not provided in the end portion near the tube sheet.

FIG. 3 is a sectional structural view showing an example in which the heat exchanger of the present invention is used in an absorption refrigerator. In FIG. 3, an evaporator heat transfer tube unit 4E and an absorber heat transfer tube unit 4A are arranged on the left and right in a container surrounded by the shell 1.
In the evaporator heat transfer tube unit 4E, the cold water flows inside the heat transfer tube, and the refrigerant liquid flows down from the liquid spraying device 5E to the outside of the heat transfer tube. During cooling, the refrigerant water exchanges heat with the cold water and a part of the refrigerant liquid evaporates. . In the absorber heat transfer tube unit 4A, the cooling water flows inside the heat transfer tube, and the absorbing solution flows down from the liquid spraying device 5A to the outside of the heat transfer tube, and absorbs the refrigerant vapor from the evaporator during the flow.

An eliminator 6 is arranged between the evaporator and the absorber to prevent the droplets from scattering. Further, in order to prevent heat loss between the refrigerant reservoir in the lower part of the evaporator and the absorbent solution reservoir in the lower part of the absorber, an inverted U-shaped heat insulating space is provided. It is also possible to replace the evaporator part with a regenerator and further replace the absorber part with a condenser. In this case, the liquid spraying device 5A is unnecessary in the condenser section. In the heat exchanger tube unit for a regenerator, a heating fluid (steam, hot water, etc.) flows in the heat exchanger tube, an absorbing solution flows down outside the heat exchanger tube, and a refrigerant vapor is generated from the absorbing solution in the middle of the flowing down. In the heat transfer tube unit for the condenser, the cooling water flows inside the heat transfer tube, the refrigerant vapor from the regenerator is condensed outside the heat transfer tube, and the condensed refrigerant liquid flows down.

FIG. 4 is a sectional structural view showing another example in which the heat exchanger of the present invention is used in an absorption refrigerator. In FIG. 4, an evaporator heat transfer tube unit 4E is provided in a container surrounded by the shell 1.
And three heat transfer tube units 4A for absorbers are arranged alternately. With this arrangement, the refrigerant vapor evaporated in the evaporator flows toward the adjacent absorber heat transfer tube unit, so the vapor flow velocity is extremely low, so the pressure loss is small and the performance of the absorption refrigerator can be improved. . In the heat transfer tube unit for an evaporator, cold water flows inside the heat transfer tube, the refrigerant liquid flows down to the outside of the heat transfer tube, and heat is exchanged with the cold water during the flow to partially evaporate the refrigerant liquid. In the heat transfer tube unit for the absorber, cooling water flows inside the heat transfer tube, the absorbing solution flows down outside the heat transfer tube, and the refrigerant vapor from the evaporator is absorbed during the flow.

At the top of the evaporator heat transfer tube unit 4E,
Refrigerant spraying device 5E is also used for absorber heat transfer tube unit 4A.
The absorbent solution spraying device 5A is disposed on the upper part of.
The spraying devices 5E and 5A may be integrally formed with each heat transfer tube unit or may be installed independently. Also in this spraying device, it is preferable that the surface in contact with the liquid is subjected to hydrophilic treatment. This hydrophilic treatment makes it possible to obtain a good spraying state. At the lower part of the evaporator heat transfer tube unit 4E or the absorber heat transfer tube unit 4A, a collector 7 for separating and recovering the refrigerant and the absorbing solution is provided.
To provide. FIG. 4 shows an example in which the collector 7 is provided at the bottom of the evaporator heat transfer tube unit. The refrigerant liquid recovered by this collector can be guided to a refrigerant liquid reservoir (not shown) to prevent mixing with the absorbing solution.

Also in FIG. 4, the evaporator part may be replaced by a regenerator, and the absorber part may be replaced by a condenser. In this case, the liquid spraying device 5A is unnecessary in the condenser section. In the heat exchanger tube unit for a regenerator, a heating fluid (such as steam hot water) flows in the heat exchanger tube, an absorbing solution flows down outside the heat exchanger tube, and a refrigerant vapor is generated from the absorbing solution during the flow. In the heat transfer tube unit for the condenser, the cooling water flows inside the heat transfer tube, and the refrigerant vapor from the regenerator condenses outside the heat transfer tube.
This condensed refrigerant liquid flows down. FIG. 5 is a schematic configuration diagram showing the cold water and the header structure of the cooling water in FIG.
In FIG. 5, the structure of the cold water header attached to one tube sheet and the cooling water header is illustrated. In FIG.
Cold water flows into the header 10 through the inlet 8 and the branch passage 8E.
Through the evaporator heat transfer tube unit 4E and flows out from a header (not shown) provided on the tube plate at the other end.

The cooling water is supplied from the inlet 9 to the header 11
To the absorber heat transfer tube unit 4A from the branch passage 9A.
It flows out through a header (not shown) provided on the tube sheet at the other end. In Figure 5, with the cooling water header up,
The cold water header is located below, but of course the reverse is also true. Further, by providing the headers 10 and 11 with partition plates, it is possible to set an arbitrary number of passes. The illustrated example is not limited to a single-effect absorption refrigerator, but can naturally be applied to a multiple-effect absorption refrigerator or absorption cold / hot water machine. Further, the evaporator, the absorber, the regenerator, and the condenser can be housed in an integral shell or in a twin shell shell.

[0015]

EFFECTS OF THE INVENTION According to the present invention, the heat transfer tubes are brought into close contact with each other, so that the heat transfer tubes can be made compact and the ends of the tubes can be easily fixed, and an ordinary circular tube or the like can be used as the heat transfer tube. It was possible to obtain a heat exchanger that is reliable in terms of strength. Furthermore, the liquid flow in the horizontal direction was promoted on the close surface of the heat transfer tube, and as a result, a uniform liquid film was formed on the heat transfer surface, and a high performance heat exchanger could be obtained. Also,
Using the heat exchanger of the present invention, a compact and high-performance absorption refrigerator can be provided.

[Brief description of drawings]

FIG. 1 is a plan view of a cross-sectional configuration diagram showing an example of a heat exchanger of the present invention.

FIG. 2 is a cross-sectional configuration diagram showing another example of the heat exchanger of the present invention, (a) is a front view, (b) is a side view, and (c) is (a).
3 is a cross-sectional view taken along line X-X of FIG.

FIG. 3 is a cross-sectional configuration diagram showing an example in which the heat exchanger of the present invention is used in an absorption refrigerator.

FIG. 4 is a cross-sectional configuration diagram showing another example in which the heat exchanger of the present invention is used in an absorption refrigerator.

5 is a schematic configuration diagram showing cold water and a header structure of the cooling water in FIG.

[Explanation of symbols]

1: Shell, 2: Tube plate, 3: Heat transfer tube, 4, 4A, 4E:
Heat transfer tube unit, 5, 5A, 5E: liquid spraying device, 6: eliminator, 7: collector, 8: cold water inlet, 9: cooling water inlet, 10: cold water header, 11: cooling water header, 1
2: Plate fins

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) F25B 39/04 F25B 39/04 Q F28F 1/22 F28F 1/22 Z 13/18 13/18 B (72 ) Inventor Ken Ishiyama 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo Inside the EBARA CORPORATION (72) Inventor Toshio Matsubara 11-11 Haneda-Asahi-cho, Ota-ku, Tokyo Inside the EBARA CORPORATION (72) Inventor Ito No. 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo (72) Inventor, Ekuha Co., Ltd. Kikuichi Mori 11-11 Haneda-Asahi-cho, Ota-ku, Tokyo (72) Inventor, Koichi Kunimasa Tokyo 11-1 Haneda Asahi-cho, Ota-ku, Ebara Corporation (72) Inventor Hiroshi Ishii 11-11 Haneda-Asahi-cho, Ota-ku, Tokyo (72) Inventor Yuko Imoto Hakata, Ota-ku, Tokyo 11-1 Taasahimachi F term in EBARA CORPORATION (reference) 3L093 BB00 MM02 MM05 3L103 AA11 AA18 AA35 BB33 CC18 CC30 DD08 DD33 DD95

Claims (7)

[Claims] 1. A heat exchanger for exchanging heat between an in-tube fluid flowing inside a heat transfer tube and an outside fluid flowing outside the heat transfer tube, wherein the heat transfer tubes are arranged in a horizontal direction, and an outer surface of the heat transfer tube is predetermined. A plurality of heat transfer tube units are vertically stacked at intervals to form a heat transfer tube unit, and a plurality of the heat transfer tube units are arranged in the horizontal direction at predetermined intervals, and both ends of the heat transfer tube are joined to a tube plate or a header for a fluid in the tube. A plate-like fin is provided at a predetermined interval below the heat transfer tube so as to be substantially in close contact with the upper surface of the heat transfer tube installed in the lower stage of the heat transfer tube. 2. The outer surface of the heat transfer tube is subjected to a hydrophilic treatment for improving wettability.
The heat exchanger described. 3. An evaporator, an absorber, which constitutes an absorption refrigerator,
An absorption refrigerator comprising the heat exchanger according to claim 1 or 2 as at least one of a regenerator and a condenser. 4. The absorption refrigerator according to claim 3, wherein the heat exchanger is used as a condenser, or a refrigerant spraying device is provided above the heat transfer tube unit to be used as an evaporator. Absorption refrigerator that does. 5. The absorption refrigerator according to claim 3, wherein the heat exchanger is used as an absorber or a regenerator by providing a device for spraying an absorbing solution on an upper part of a heat transfer tube unit. . 6. The absorption refrigerator according to claim 3, wherein the heat exchangers are alternately arranged on the upper part of the heat transfer tube unit as a refrigerant spraying device.
An absorption refrigerating machine comprising an absorption solution spraying device, a recovery unit for separating and recovering either a refrigerant or an absorption solution provided at a lower part, and alternately used as an evaporator and an absorption unit. 7. The absorption refrigerating machine according to claim 3, wherein the heat exchanger is provided with an absorbing solution spraying device at every other row on the upper part of the heat transfer tube unit, and the refrigerant or the absorbing solution is separated and recovered at the lower part. An absorption chiller characterized by being provided with a recovery device for use as a regenerator and a condenser alternately.