JPH07190548A - Absorption type refrigerator - Google Patents

Abstract

PURPOSE:To remarkably reduce the reserving capacity of an ammonia aqueous solution having irritating odor by very increasing a heat transfer area as compared with a conventional shell and tube type by employing a plate fin type structure as a structure of a heat exchanger and hence simplifying the exchanger when an apparatus of the same heat transfer amount is formed. CONSTITUTION:An ammonia absorption type refrigerator comprises an evaporator, absorber, regenerator, fractionating tower and condenser, wherein a heat exchanger 31 provided at least in the regenerator 4 of the evaporator, the absorber, the tower and the condenser has flat platelike partition walls 32 disposed in parallel, fluid passages 33 formed between the walls 32, and waveformlike fins 34 disposed at the passages 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator using an aqueous ammonia solution as an absorption liquid.

[0002]

2. Description of the Related Art Conventionally, as an absorption type refrigerator using an aqueous ammonia solution as an absorbing liquid, for example, JP-A-61-2 is known.
There is one disclosed in Japanese Patent No. 11673.

This absorption refrigerator has an evaporator for evaporating ammonia, an absorber for absorbing the ammonia gas evaporated in the evaporator into an aqueous ammonia solution, and an aqueous ammonia solution in which the ammonia is absorbed by the absorber. It has a regenerator that heats to obtain ammonia gas, a rectification column for removing the moisture associated with the ammonia gas obtained by this regenerator, and a condenser that condenses the ammonia gas from this rectification column. is doing.

In this absorption refrigerator, ammonia is used as a refrigerant to cool the fluid to be cooled by the evaporator.
The heat generated when the ammonia gas is absorbed in the aqueous ammonia solution by the absorber is cooled by the cooling fluid.

By the way, heat is exchanged in the evaporator, the absorber, the regenerator and the condenser, and a shell-and-tube type heat exchange structure has been adopted in this heat exchange section.

According to this shell-and-tube heat exchange structure, the diameter of the tubes for heat exchange is about 16 to 32 mm, and a large number of tubes are arranged at equal intervals with a square pitch. Met.

[0007]

As described above, the evaporator,
Since the structure of the heat exchange part in the absorber, regenerator and condenser is shell and tube type, the filling rate of the heat transfer tube is poor, and therefore a certain amount of heat transfer is obtained when dealing with toxic solutions such as ammonia. Therefore, there is a drawback that the amount of the solution held increases.

Further, in the shell-and-tube type, the size of the main body is large, and the height is particularly high, which causes inconvenience in putting it in a building. Therefore, an object of the present invention is to provide an absorption refrigerator that can solve the above problems.

[0009]

In order to solve the above problems, the first means of the present invention is an evaporator, an absorber, a regenerator,
In an absorption refrigerator having a rectification column and a condenser, and using ammonia as a refrigerant and ammonia water as an absorption liquid, one of the evaporator, absorber, regenerator, rectification column and condenser , A plurality of heat exchange portions provided in at least one of the plate-shaped partition walls arranged in parallel, each fluid passage formed between these partition walls, and each of these fluid passages or every other fluid passage. It is an absorption refrigerating machine composed of the corrugated fins.

In order to solve the above-mentioned problems, the second means of the present invention is the same as the first means, wherein the corrugated fins arranged in the fluid passage are arranged in the width direction parallel to the wave forming direction. This is an absorption refrigerator in which small fins are cut at predetermined intervals to form small fins, and adjacent small fins are arranged so that their phases are shifted from each other in the wave forming direction.

Further, in order to solve the above-mentioned problems, the third means of the present invention is the same as the first means, wherein the heat exchange section of the regenerator is formed with a plurality of partition walls and between these partition walls. A first fluid passage which is configured by corrugated fins arranged in each fluid passage, and in which fins in adjacent fluid passages are arranged so that the arrangement directions of the waves of the fins are orthogonal to each other and the waves are bent in the horizontal direction. To supply the concentrated aqueous ammonia solution to the second fluid passage provided with fins whose waves bend in the vertical direction, and to supply the concentrated aqueous ammonia solution to the upper part of the second fluid passage. And a supply port for supplying the concentrated ammonia aqueous solution supplied to the supply passage portion to the partition wall corresponding to the supply passage portion substantially evenly in the first fluid passage. A plurality formed absorption chiller.

[0012]

According to the above construction, since the plate fin type structure is adopted as the structure of the heat exchange section in at least one of the evaporator, the absorber, the regenerator, the rectification column and the condenser, For example, the heat transfer area per unit volume is much larger than that of the shell-and-tube type, so that when configuring a device with the same heat transfer amount, the heat exchange section can be made compact and therefore has an irritating odor. The holding capacity of the aqueous ammonia solution can be significantly reduced.

Further, since the fins have a predetermined width and the small fins having the predetermined width are arranged so that their phases are alternately shifted, the flow path of the heat exchange fluid can be made to meander. The heat exchange rate can be improved by sufficiently bringing the two kinds of fluid into contact with each other.

Further, in the heat exchange section of the regenerator, since the plurality of supply ports for supplying the concentrated aqueous ammonia solution to the first fluid passage are formed substantially evenly in the partition wall, the concentrated aqueous ammonia solution is provided in the first fluid passage. It can be dispersed and supplied, so that the heating efficiency of the concentrated aqueous ammonia solution can be improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. First, a schematic configuration of an ammonia absorption refrigerator (hereinafter, simply referred to as an absorption refrigerator) that uses ammonia as a refrigerant and an aqueous ammonia solution as an absorption liquid will be described with reference to FIG.

That is, the absorption refrigerator 1 according to this embodiment.
Is an evaporator 2 for evaporating an ammonia solution to obtain an ammonia gas, an absorber 3 for absorbing the ammonia gas evaporated by the evaporator 2 into a dilute aqueous ammonia solution having a low concentration, and an absorber 3 for absorbing the ammonia gas. The regenerator 4 that absorbs the ammonia gas to heat the concentrated aqueous ammonia solution in which the ammonia concentration has become high to separate the ammonia gas and regenerate the ammonia, and the moisture accompanying the ammonia gas separated by the regenerator 4 A rectification column 5 for removing by an ammonia liquid introduced from a condenser (described later) and a condenser 6 for condensing the ammonia gas from which water has been removed by the rectification column 5 are provided. A plate fin type heat exchange unit is arranged in the container body of each of these devices.

The absorption refrigerator 1 includes an evaporator 2
For transferring ammonia gas from the absorber to the absorber 3
An ammonia gas transfer pipe 11, a concentrated ammonia aqueous solution transfer pipe 12 for transferring the concentrated aqueous ammonia solution in the absorber 3 to the regenerator 4, and a first ammonia gas transfer pipe for transferring the ammonia gas from the regenerator 4 to the rectification column 5. 2 Ammonia gas transfer pipe 13
A third ammonia gas transfer pipe 14 for transferring the ammonia gas from the rectification column 5 to the condenser 6, and an ammonia liquid transfer pipe 15 for transferring the ammonia liquid from the condenser 6 to the evaporator 2. An ammonia liquid return pipe 16 for returning a part of the ammonia liquid in the ammonia liquid transfer pipe 15 into the rectification column 5 and a dilute ammonia aqueous solution whose concentration is thinned by the evaporation of ammonia in the regenerator 4. A dilute ammonia solution transfer pipe 17 for transferring to the absorber 3, an ammonia liquid circulation pipe 18 for recirculating the ammonia liquid accumulated at the bottom of the evaporator 2 to the upper portion thereof, and absorbing a part of this ammonia liquid as necessary. Ammonia liquid bypass pipe 1 to supply to vessel 3
9, a cooled fluid supply pipe 21 for supplying a cooled fluid (also referred to as brine) to the heat exchange section in the evaporator 2,
A heating fluid supply pipe 22 for supplying steam as a heating fluid to the heat exchange section in the regenerator 4, and the absorber 3
And as a cooling fluid in each heat exchange section in the condenser 6,
For example, a cooling fluid supply pipe 23 for supplying cooling water is provided.

Further, in the absorption refrigerator 1, the diluted ammonia aqueous solution transfer pipe 17 and the concentrated ammonia aqueous solution transfer pipe 1 are provided.
First heat exchanger (solution heat exchanger) 7 provided between
And a second heat exchanger (liquid gas heat exchanger) 8 provided between the first ammonia gas transfer pipe 11 and the ammonia liquid transfer pipe 15.

The heat exchangers 7 and 8 are for recovering heat within the system of the absorption cycle, and are provided with heat exchange sections like the respective devices 2 to 6. .

Here, a schematic refrigeration cycle will be described. That is, the ammonia liquid as the refrigerant supplied from the condenser 6 is sent to the evaporator 2, where it is decompressed and evaporated. At this time, heat is taken from the fluid to be cooled (brine) supplied to the heat exchange section in the evaporator 2 to cool the fluid to be cooled.

The ammonia gas generated in the evaporator 2 enters the absorber 3 where it is absorbed by the dilute aqueous ammonia solution to generate heat. This heat is cooled by cooling water. Next, the concentrated ammonia aqueous solution, which has absorbed ammonia gas in the absorber 3 and has a high concentration, is sent into the regenerator 4, where it is heated by steam to evaporate ammonia. That is, the ammonia is separated from the concentrated aqueous ammonia solution to be regenerated.

The ammonia gas separated in the regenerator 4 enters the rectification column 5, where a part of the ammonia liquid already condensed in the condenser 6 is introduced and brought into contact with the ammonia gas to be contained in the ammonia gas. The contained water is removed along with the ammonia solution.

The ammonia gas from which the water has been removed is
The water is sent to the condenser 6, where it is cooled by the cooling water passing through the absorber 3 and condensed. Then, the condensed ammonia liquid is supplied to the inside of the evaporator 2 after its heat is given to the ammonia gas by the second heat exchanger 8. In the first heat exchanger 7, the heat of the diluted ammonia solution is given to the concentrated ammonia solution side.

The above absorption cycle is carried out continuously,
The fluid to be cooled is cooled. Next, the above devices 2 to 8
The structure of the heat exchange section provided in the above will be described with reference to the drawings.

A plate fin type heat exchanger is used as the heat exchange section in each of the devices 2 to 8. For example, focusing on the heat exchange section in the regenerator 4, as shown in FIG. 2, the heat exchange section 31 has a plurality of flat plate-shaped partition walls 32 arranged in parallel and between these partition walls 32. Each of the fluid passages 33 formed and the corrugated fins 34 arranged in each of the fluid passages 33 are formed. In each of the fluid passages 33, alternately, that is, in every other fluid passage 33. The directions of the arranged fins 34 are orthogonal to each other.

That is, the first fins 34A arranged in the first fluid passage 33A to which the concentrated aqueous ammonia solution is supplied through the supply pipe portion 12a are arranged so that the bending direction of the wave is horizontal. The second fins 34B arranged in the second fluid passage 33B to which the steam is supplied are arranged such that the wave bending direction is the vertical direction.

More specifically, the concentrated aqueous ammonia solution is flown down in the vertical direction and the steam is passed horizontally. As described above, by using the plate fin type heat exchange section 31, the heat transfer area per unit volume is increased ten times or more as compared with the conventional shell and tube type, and therefore the same amount of heat is exchanged. In this case, the amount of the aqueous ammonia solution held can be greatly reduced, for example,
It can be reduced to about 4.

In FIG. 2, the wave bending direction of each fin 34 in each fluid passage 33 is shown to be the same over the entire width. However, the wave bending direction is changed in the middle depending on the direction in which the fluid is discharged. You may change it.

That is, as shown in FIG. 3, the flow direction of the steam B in the second fluid passage 33B of the regenerator 4 is
It may be changed downward from the horizontal direction. In this case, the bending direction of the wave of the second fin 34B is changed by 90 degrees on the way.

Further, in FIG. 2 and FIG. 3, the partition wall 32
Although the fins are arranged in all of the fluid passages 33 formed between them, for example, one fin 34 may be placed in the fluid passage 33 depending on the device.

Furthermore, in some cases, each fluid passage 33
The bending direction of the waves of the fins 34 provided inside is made horizontal, and the flow directions of the fluids supplied to the first fluid passages 33A and the second fluid passages 33B provided alternately are opposite to each other. May be.

Next, a second embodiment of the present invention will be described with reference to FIGS.
It will be explained based on. In the above embodiment, the waves of the fins arranged in each fluid passage are arranged so as to be continuous,
For example, the fins may be shortened in the width direction, and the positions (phases) of wave peaks (or valleys) may be alternately shifted.

That is, as shown in FIG. 4, the heat exchange section 41 in the absorber 3 will be described. A first fluid passage 42A through which the dilute aqueous ammonia solution flows down from the supply pipe section 17a and also the ammonia gas flows. The plurality of small fins 43a, which are shortened in the width direction, are arranged side by side in the fins 43 arranged at, and the wave pitches of the small fins 43a provided at intervals of one are shifted by half.
The peaks (or valleys) of the waves are provided such that the wave phases are shifted in the vertical direction.

The second fluid passage 4 through which the cooling water passes
2B is not provided with fins. With such a structure, as shown in FIG.
Since the dilute aqueous ammonia solution flowing down to 2A flows in a complicated path so as to meander in the horizontal direction from the upper part to the lower part, the contact with the ammonia gas becomes good and the absorption efficiency of the ammonia gas improves.

Further, in the above embodiment, the bending direction of the wave is described as the vertical direction. However, for example, like the heat exchange section 51 of the regenerator 4 shown in FIG. 6, the concentrated ammonia aqueous solution is flowed down from the supply pipe section 12a. The width of the fin 53 provided in the first fluid passage 52A may be narrowed, and the bending direction of the wave in the narrowed small fin 53a may be horizontal.

Further, in FIG. 6, the fins 5 are provided only in the first fluid passage 52A through which the concentrated aqueous ammonia solution flows down.
3, the fins 53 similar to the above may be arranged in both the first and second fluid passages 52A and 52B, as shown in FIG. 7, for example.

Next, a third embodiment of the present invention will be described with reference to FIG. In the first embodiment, one of the two types of fluid for heat exchange is made to fall from the supply pipe portion provided above the fluid passage, but this third embodiment In the embodiment, the fluid is supplied from the partition wall forming the fluid passage.

That is, as shown in FIG. 8, the heat exchange section 61 of the regenerator 4 comprises a plurality of partition walls 62 and the respective partition walls 6 thereof.
It is composed of corrugated fins 64 arranged in each fluid passage 63 formed between two, and the arrangement directions of the waves of the fins 64 in adjacent fluid passages 63 are orthogonal to each other.

Further, the dilute aqueous ammonia solution is flowed down into the first fluid passage 63A provided with the first fins 64A in which the waves bend in the horizontal direction, and the second fins 64B in which the waves bend in the vertical direction are provided. Steam is supplied to the second fluid passage 63B.

Further, a plurality of partition members (also referred to as side seals) 65 are provided above the second fluid passage 63B.
Is inserted in the horizontal direction to form a supply passage portion 66 for the concentrated aqueous ammonia solution.

In the partition wall 62 corresponding to the supply passage portion 66, a plurality of fluid supply ports 67 opening to the first fluid passage 63A side are formed at predetermined intervals (equally). A plurality of partition members 65 are provided for sealing and reinforcement.

Therefore, when the concentrated ammonia aqueous solution is supplied into the regenerator 4, the concentrated ammonia aqueous solution is guided to the supply passage portion 66 and is evenly distributed and supplied from the supply ports 67 into the first fluid passage 63A. To be done.

That is, the heating efficiency of the concentrated aqueous ammonia solution is improved. In each of the above-mentioned embodiments, the case where the structure of the heat exchange section is applied to the regenerator 4 or the absorber 3 has been described. This is applicable to the heat exchange section, and the plate fin type and the shell and tube type can be used together.

Further, the fins are attached to the partition walls in each heat exchange section by brazing.

[0045]

As described above, according to the configuration of the present invention, in an absorption refrigerator using ammonia as a refrigerant and an aqueous ammonia solution as an absorbing liquid, an evaporator, an absorber, a regenerator, and a rectification column are provided. And, as the structure of the heat exchange section in at least one of the condensers,
Since the plate fin type structure is adopted, the heat transfer area per unit volume of the heat exchanger is much larger than that of the conventional shell and tube type, so when configuring devices of the same heat transfer amount, heat exchange The part can be made compact, and therefore the holding capacity of the aqueous ammonia solution having an irritating odor can be significantly reduced. Further, since the size of the device itself can be reduced, and especially the height can be reduced, the installation space can be small, which is advantageous for transportation, for example.

The plate fin type fins have a predetermined width, and the small fins having the predetermined width are
By arranging the phases so that they are alternately shifted, the flow path of the heat exchange fluid can be made to meander,
The heat exchange rate can be improved by sufficiently bringing the two kinds of fluid into contact with each other.

Further, in the heat exchange section of the regenerator, the plurality of supply ports for supplying the concentrated aqueous ammonia solution to the first fluid passage are formed substantially evenly on the partition wall, so that the concentrated aqueous ammonia solution is introduced into the first fluid passage. It can be dispersed and supplied, so that the heating efficiency of the concentrated aqueous ammonia solution can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic overall configuration of an absorption refrigerator according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a structure of a heat exchange section in the absorption refrigerator according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a structure of a modified example of the heat exchange section in the absorption chiller according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a structure of a heat exchange section in an absorption refrigerator according to a second embodiment of the present invention.

FIG. 5 is a partially cutaway front view for explaining the operation of the heat exchange section in the second embodiment.

FIG. 6 is a perspective view showing the structure of a modification of the heat exchange section in the regenerator of the second embodiment.

FIG. 7 is a perspective view showing the structure of a modification of the heat exchange section in the regenerator of the second embodiment.

FIG. 8 is a perspective view showing a structure of a heat exchange section in an absorption refrigerator according to a third embodiment of the present invention.

[Explanation of symbols]

 1 Absorption Refrigerator 2 Evaporator 3 Absorber 4 Regenerator 5 Fractionator 6 Condenser 7 First Heat Exchanger 8 Second Heat Exchanger 31 Heat Exchange Section 32 Partition Wall 33 Fluid Passage 34 Fin 41 Heat Exchange Section 42A No. 1 fluid passage 42B 2nd fluid passage 43 fin 43a small fin 51 heat exchange section 52A 1st fluid passage 52B 2nd fluid passage 53 fin 53a small fin 61 heat exchange section 62 partition wall 63 fluid passage 64 fin 66 supply passage section 67 supply port

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Konishi 4-1-2 Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture Osaka Gas Co., Ltd. (72) Inventor Takashi Onishi 4-chome, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture No. 1-2 Osaka Gas Co., Ltd. (72) Inventor Tetsuji Horie 1-10 Fuso-cho, Amagasaki City, Hyogo Prefecture Sumitomo Precision Industries Co., Ltd. (72) Katsio Iwata 1-10 Fuso-cho, Amagasaki City, Hyogo Prefecture Sumitomo Precision Industries Co., Ltd. (72) Inventor Tetsuro Furukawa 5-3 28 Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd. (72) Kimio Ochi, Nishikujo 5-chome, Konohana-ku, Osaka City, Osaka Prefecture 3-28 Hitachi Shipbuilding Co., Ltd. (72) Inventor Mitsufumi Matsuda 5-3-8 Nishikujo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd.

Claims (3)

[Claims] 1. An absorption refrigerating machine having an evaporator, an absorber, a regenerator, a rectification column and a condenser, wherein ammonia is used as a refrigerant and ammonia water is used as an absorbing liquid. Among the absorber, the regenerator, the rectification column and the condenser, a heat exchange portion provided in at least one of the flat plate-shaped partition walls arranged in parallel,
An absorption refrigerator comprising: each fluid passage formed between these partition walls; and a wave-shaped fin arranged in each fluid passage or every other fluid passage. 2. A corrugated fin disposed in the fluid passage,
It is characterized in that it is cut into small fins at predetermined intervals in the width direction parallel to the wave forming direction, and that adjacent small fins are arranged so that their phases are shifted from each other in the wave forming direction. The absorption refrigerator according to claim 1. 3. The heat exchange section of the regenerator comprises a plurality of partition walls and corrugated fins arranged in the respective fluid passages formed between the respective partition walls, and in each adjacent fluid passage. The fins are arranged such that the wave arrangement directions are orthogonal to each other, the concentrated ammonia aqueous solution is supplied to the first fluid passage provided with the fins in which the waves bend in the horizontal direction, and the fins in which the waves bend in the vertical direction are provided. A heating fluid is supplied to the fluid passage, and a supply passage portion for supplying a concentrated aqueous ammonia solution is formed on the upper portion of the second fluid passage, and a partition corresponding to the supply passage portion and a supply passage portion are formed. The absorption refrigerator according to claim 1, wherein a plurality of supply ports are formed to supply the supplied concentrated aqueous ammonia solution in the first fluid passage substantially uniformly.