JP2000065435A - Ammonia absorption refrigerator - Google Patents

Abstract

(57) Abstract: An ammonia absorption refrigerator having an inexpensive subcooler is provided. A heat exchange is performed between an ammonia vapor transfer line for guiding ammonia vapor from an evaporator and an ammonia solution transfer line for guiding an ammonia solution from a condenser to convert the heat of the ammonia solution to ammonia. In an ammonia absorption refrigerator including a supercooler 21 for recovering on the steam side, the supercooler 21 is inserted into an outer pipe 22 forming an ammonia vapor transfer pipe 11 and an inside of the outer pipe 22. Inner pipe 2 which forms ammonia liquid transfer pipe 12
3 and an annular fin 24 attached to the outer peripheral surface of the inner tube 23.
Are disposed below the center of the outer tube 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ammonia absorption refrigerator.

[0002]

2. Description of the Related Art Conventionally, in an ammonia absorption refrigerator, sensible heat of an ammonia liquid condensed in a condenser is recovered in order to improve thermal efficiency.

[0003] That is, as shown in FIG.
Ammonia vapor transfer pipe line 61 for transferring the ammonia vapor evaporated in step A to absorber 52 and ammonia liquid transfer pipe line 62 for transferring the ammonia liquid condensed in condenser 53 to evaporator 51 are provided between A supercooler 71 for cooling the ammonia liquid by steam is disposed. As the supercooler 71, a plurality of thin plate members are stacked to form alternately fluid passages, and a fluid passage is formed in each passage. Laminated plate fin type heat exchangers provided with a large number of fins so as to flow uniformly are used.

[0004]

According to the above conventional structure, the supercooler 71 for supercooling the ammonia liquid has the following features.
Since a plate-fin type heat exchanger is used, the production cost is high.

[0005] Therefore, an object of the present invention is to provide an ammonia absorption refrigerator having an inexpensive supercooling section.

[0006]

In order to solve the above-mentioned problems, an ammonia absorption refrigerator of the present invention comprises an evaporator for evaporating an ammonia solution introduced from a condenser via an ammonia solution transfer line, and an evaporator for evaporating the ammonia solution. The heat exchange between the ammonia vapor transfer pipe and the ammonia liquid transfer pipe and the ammonia liquid transfer pipe is conducted to guide the ammonia vapor evaporated by the vessel to the absorber, and the heat of the ammonia liquid is recovered to the ammonia vapor side. In an ammonia absorption refrigerator having a supercooling unit, the supercooling unit is inserted into an outer pipe forming an ammonia vapor transfer pipe and an ammonia liquid transfer pipe by being inserted into the outer pipe. It comprises an inner tube and fins attached to the outer peripheral surface of the inner tube. In the above structure, the inner tube is opposed to the center of the outer tube. Te, those disposed below closer.

In the above structure, the supercooling section for performing heat exchange between the ammonia vapor transfer pipe and the ammonia liquid transfer pipe is composed of an outer pipe and an inner pipe having fins attached to the outer peripheral surface. Due to the double tube structure, the manufacturing cost can be reduced as compared with the case of using a laminated plate fin type heat exchanger.

Further, since the inner tube is disposed below the center of the outer tube, for example, the ammonia vapor from the evaporator is wet vapor, and the double tube composed of the outer tube and the inner tube is formed. Even when gas-liquid separation occurs in the horizontal portion of the tube, the liquid flowing at the bottom of the outer tube comes into contact with the fins, so that heat exchange can be sufficiently performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ammonia absorption refrigerator according to an embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the ammonia absorption refrigerator according to the present embodiment has an evaporator 1 for evaporating an ammonia liquid as a refrigerant, and an ammonia vapor transfer pipe for evaporating the ammonia vapor evaporated by the evaporator 1. An absorber 2 which is guided through a passage 11 and is absorbed by an aqueous ammonia solution; and an ammonia aqueous solution having an increased concentration by absorbing the ammonia vapor by the absorber 2 is guided through an ammonia aqueous solution transfer pipe (not shown). A regenerator (not shown) for regenerating
And a condenser 3 for guiding and condensing the ammonia vapor obtained by the regenerator through an ammonia vapor transfer pipe (not shown), and transferring the ammonia liquid obtained by the condenser 3 to the evaporator 1. And an ammonia liquid transfer line 12.

Then, in order to improve the thermal efficiency of the refrigerator, the ammonia liquid transferred from the condenser 3 is transferred to the middle of the ammonia vapor transfer pipe 11 for transferring the ammonia vapor from the evaporator 1 to the absorber 2. A supercooler (supercooling unit) 21 for performing cooling is arranged.

As shown in FIGS. 2 and 3, the subcooler 21 includes an outer tube 22 forming at least a part (or all) of the ammonia vapor transfer line 11, and an outer tube 22 of the outer tube 22. Ammonia liquid transfer pipe 1 inserted inside
2, and a plurality of annular fins 24 attached to the outer periphery of the inner tube 23 at predetermined intervals.
The insertion position of No. 3 is set to a lower position with respect to the center of the outer tube 22. Of course, the above-mentioned annular fin 24
Is provided to compensate for the shortage of heat exchange between tubes (shortage of heat transfer).

In the above configuration, during the operation of the refrigeration cycle, a high-temperature ammonia liquid (for example, an ammonia liquid having a concentration of 99.8% at 40 ° C.) from the condenser 3 flows through the inner pipe 23. And low-temperature ammonia vapor from the evaporator 1 (for example, at −34 ° C., 99.8%
Concentration of ammonia vapor) is passed through the outer tube 22.
Therefore, the heat of the ammonia liquid flowing in the outer tube 22 is recovered by the ammonia vapor flowing in the inner tube 23.

At this time, when the ammonia vapor from the evaporator 1 is wet vapor, and gas-liquid separation occurs at the horizontal portion of the double pipe portion composed of the outer pipe 22 and the inner pipe 23, In this case, the liquid flows through the bottom of the outer tube 22. However, since the inner tube 23 is disposed at a lower position, for example, the annular fins 24 come into contact with the liquid, and heat exchange is sufficiently performed.

As described above, the supercooler for performing heat exchange between the ammonia vapor transfer pipe and the ammonia liquid transfer pipe is
Because it was a double tube structure consisting of an outer tube and an inner tube with fins attached to the outer peripheral surface, as compared with the conventional case using a laminated plate fin type heat exchanger,
The manufacturing cost can be reduced, and there is no need to install a heat exchanger provided separately from the pipeline, so that the installation space for the equipment can be reduced.

Also, since the inner tube is disposed lower than the center of the outer tube, for example, the ammonia vapor from the evaporator 1 is wet vapor and the outer tube 22 and the inner tube 23 When gas-liquid separation occurs at the horizontal portion of the double pipe section, the liquid flowing at the bottom of the outer pipe body 22 comes into contact with the annular fin 24, and heat exchange can be sufficiently performed.

In the above embodiment, the fin attached to the inner tube is formed in a ring shape, but may be a band-like fin parallel to the tube axis direction, for example.

[0018]

As described above, according to the structure of the present invention, the supercooling section for performing heat exchange between the ammonia vapor transfer pipe and the ammonia liquid transfer pipe is provided with fins on the outer pipe and the outer peripheral surface. The inner pipe body has a double-pipe structure, so that the manufacturing cost can be reduced as compared with the conventional case using a laminated plate fin-type heat exchanger, There is no need to install a heat exchanger provided separately from the piping, and the installation space for the equipment is reduced.

Further, since the inner tube is disposed lower than the center of the outer tube, for example, the ammonia vapor from the evaporator is wet vapor, and the double tube composed of the outer tube and the inner tube is formed. Even when gas-liquid separation occurs in the horizontal portion of the tube, the liquid flowing at the bottom of the outer tube comes into contact with the fins, so that heat exchange can be sufficiently performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a main configuration of an ammonia absorption refrigerator according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a supercooler in the ammonia absorption refrigerator.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a block diagram showing a main configuration of an ammonia absorption refrigerator in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Evaporator 2 Absorber 3 Condenser 11 Ammonia vapor transfer line 12 Ammonia liquid transfer line 21 Subcooler 22 Outer tube 23 Inner tube 24 Annular fin

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takashi Onishi 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Yukio Hiranaka 4-chome, Hirano-cho, Chuo-ku, Osaka-shi, Osaka 1-2 Inside Osaka Gas Co., Ltd. (72) Noboru Tsubakihara, Inventor 4-1-2 Hiranocho, Chuo-ku, Osaka City, Osaka Prefecture Inside Osaka Gas Co., Ltd. (72) Katsuo Iwata 1-10 Fusocho, Amagasaki City, Hyogo Prefecture Within Sumitomo Precision Industries Co., Ltd. (72) Inventor Masaharu Furuji 1-89, Minamikohoku, Suminoe-ku, Osaka, Osaka Prefecture 7-89 Hitachi Zosen Corporation (72) Inventor Yu Fujita 1-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka 7-89 Inside Hitachi Zosen Corporation (72) Inventor Takeshi Yano Osaka 7-89 Minami Kohoku, Suminoe-ku, Osaka-shi F-term in Hitachi Zosen Corporation (reference) 3L093 LL05 MM02

Claims (2)

[Claims] An evaporator for evaporating an ammonia liquid introduced from a condenser via an ammonia liquid transfer pipe, an ammonia vapor transfer pipe for introducing ammonia vapor evaporated by the evaporator to an absorber, and the ammonia liquid In an ammonia absorption refrigerator having a supercooling unit for exchanging heat between a transfer pipe and an ammonia vapor transfer pipe and recovering heat of the ammonia liquid to an ammonia vapor side, the supercooling unit includes an ammonia vapor An outer tube forming a transfer line;
An ammonia absorption refrigerator comprising: an inner tube inserted into the outer tube to form an ammonia liquid transfer passage; and fins attached to an outer peripheral surface of the inner tube. 2. The ammonia absorption refrigerator according to claim 1, wherein the inner tube is disposed below the center of the outer tube.