JP2000154947A - Ammonia absorption refrigeration machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ammonia absorption refrigeration machine capable of sufficiently extracting and evaporating ammonia liquid even if a refrigerant regenerator is enlarged in size. SOLUTION: A double pipe structure comprising an inner tube 11 connected to an ammonia, extraction pipe 5 and an outer tube 12 connected to an ammonia liquid conveyance pipe 3 is employed for a refrigerant regenerator 6 provided between the ammonia liquid extraction pipe 5 for extracting ammonia solution containing water from an evaporator 1 and the ammonia liquid conveyance pipe 3 for conveying the ammonia liquid from a condenser to the evaporator 1, and the inner diameter d2 of an inlet section of the inner tube 11 is reduced. Because liquid flow quantity flowing inside the inner tube 11 is reduced in relation to heat transfer area in the inner tube 11, the ammonia liquid containing water is sufficiently heated and effective evaporation is performed.

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, and more particularly to a refrigerant regeneration section for heating and evaporating an ammonia liquid taken out of an evaporator.

[0002]

2. Description of the Related Art Conventionally, in an evaporator of an ammonia absorption refrigerator, a fluid to be cooled is cooled by latent heat when an ammonia liquid evaporates. However, in order to improve thermal efficiency, that is, cooling efficiency, the following method is used. The configuration was adopted.

[0003] That is, as shown in FIG.
In the middle of an ammonia vapor transfer pipe 61 for transporting the ammonia vapor evaporated in the above to an absorber (not shown), a condenser 52 is provided.
A supercooler 71 for cooling the ammonia solution transferred from the container via the ammonia solution transfer pipe 62 is provided. Further, in order to prevent water concentration in the evaporator 51, that is, accumulation of water (water Accumulates, the cooling efficiency of the fluid to be cooled is reduced), and the ammonia liquid (actually, an aqueous ammonia solution) collected in the lower portion of the evaporator 51 is condensed in the middle of an ammonia liquid extraction pipe 72. A high-temperature ammonia liquid is introduced from the heater 52 through the ammonia liquid transfer pipe 62 to heat the ammonia liquid flowing through the ammonia liquid take-out pipe 72 so as to simultaneously perform the evaporation of ammonia and the evaporation of water. Was provided. As the refrigerant regenerator 73, a double-tube type having an inner cylinder through which the ammonia liquid from the evaporator 51 flows and an outer cylinder through which the ammonia liquid from the condenser 52 flows is used.

[0004]

In the conventional structure described above, if the size of the refrigerator is to be increased, the processing capacity of the refrigerant regenerator also needs to be increased. In this case, the inner diameter of the inner cylinder and the outer cylinder is increased,
Since the increase in the flow rate of the liquid flowing through the inner cylinder is larger than the increase in the heat transfer area, which is the outer surface area of the inner cylinder, the evaporation amount of the ammonia liquid in the refrigerant regenerator decreases. Therefore, when the ammonia concentration in the evaporator decreases, the evaporating temperature of the ammonia liquid increases, so that the amount of evaporation of the ammonia liquid in the refrigerant regenerator further decreases, and the air lift function of removing the ammonia liquid is not performed, and the refrigerant regeneration function is not performed. Cannot be exhibited.

Accordingly, an object of the present invention is to provide an ammonia absorption refrigerator capable of sufficiently removing and evaporating the ammonia liquid even when the size of the refrigerant regenerator is increased.

[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 through an ammonia solution transfer pipe, and the evaporator. In an ammonia absorption refrigerator having an ammonia vapor transfer pipe for guiding the ammonia vapor evaporated in the absorber to an absorber, an ammonia liquid take-out pipe for taking out an ammonia liquid from a lower part of the evaporator and leading the ammonia liquid to the ammonia vapor transfer pipe is provided. A supercooling section for performing heat exchange between the ammonia vapor transfer pipe and the ammonia liquid transfer pipe; a refrigerant regeneration section for performing heat exchange between the ammonia liquid extraction pipe and the ammonia liquid transfer pipe; and The regeneration unit has a double pipe structure including an inner cylinder connected to the ammonia liquid extraction pipe and an outer cylinder connected to the ammonia liquid transfer pipe. A, it is obtained by reducing the inlet side of the inner diameter of the inner cylinder.

In each of the above constructions, since the inner diameter of the refrigerant regeneration section on the inlet side of the inner cylinder is reduced, the flow rate of the liquid flowing through the inner cylinder is reduced with respect to the heat transfer area of the inner cylinder. The ammonia liquid containing water flowing in the inside is sufficiently heated, and the evaporation is efficiently performed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ammonia absorption refrigerator according to a first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, the ammonia absorption refrigerator according to the first embodiment mainly includes an evaporator 1 for evaporating an ammonia liquid as a refrigerant and an ammonia vapor evaporated by the evaporator 1. An absorber (not shown) that is guided through an ammonia vapor transfer pipe 2 and absorbs the ammonia aqueous solution, and an ammonia aqueous solution transport pipe (not shown) that absorbs the ammonia vapor and increases the concentration by the absorber. A regenerator (not shown) for guiding ammonia through the regenerator, and a condenser (not shown) for guiding and condensing ammonia vapor obtained by the regenerator via an ammonia vapor transfer pipe (not shown) And an ammonia solution transfer pipe 3 for transferring the ammonia solution obtained by the condenser to the evaporator 1.

[0010] In order to improve the thermal efficiency of the refrigerator, the ammonia liquid transferred from the condenser is cooled in the middle of the ammonia vapor transfer pipe 2 for transferring the ammonia vapor from the evaporator 1 to the absorber. A supercooler (supercooling unit) 4 is provided, and furthermore, in order to prevent concentration of water in the evaporator 1, that is, accumulation of water, the ammonia liquid (ammonia liquid containing a small amount of water) in the evaporator 1 is removed. The ammonia liquid from the condenser is guided through the ammonia liquid transfer pipe 3, and the ammonia liquid guided from the evaporator 1 is heated to evaporate ammonia and water. A refrigerant regenerator (refrigerant regenerating unit) 6 for simultaneous operation is provided.

The refrigerant regenerator 6 has a double pipe structure. That is, the refrigerant regenerator 6 includes the ammonia liquid extraction pipe 5
And an outer cylinder 12 connected to the ammonia liquid transfer pipe 3, and a lower inlet portion of the inner cylinder 11 extends over a predetermined height (L) of an upper portion thereof. The inner diameter (d ₂ ) is smaller (smaller) than the inner diameter (d ₁ ). Further, an orifice 13 is provided at a connection portion (of course, in the vicinity of the connection portion) of the ammonia liquid extraction pipe 5 to the inner cylinder 11 so that a flow rate of the orifice 13 is made as uniform as possible.

The relationship between the inner diameter of the outer cylinder 12 and the inner diameter of the inner cylinder 11 is set, for example, as shown in the following equation (1). d ₂ ≦ 0.8d ₁ (1) In addition to the relationship shown in the above equation (1), the inner diameter d of the small diameter portion
₂ is in the range of 25 mm or less, and the length L of the small diameter portion is 2
It is set to a range of 0 mm or more.

The ammonia liquid transfer pipe 3 is connected in series to the subcooler 4 and the refrigerant regenerator 6, and the inlet 12a of the outer cylinder 12 of the refrigerant regenerator 6 is provided below the side wall. And the outlet 12b of the outer cylinder 12
It is provided on the upper part of the side wall part. Reference numeral 7 denotes an expansion valve provided in the middle of the ammonia liquid transfer pipe 3 downstream of the refrigerant regenerator 6.

In the above configuration, the ammonia liquid transferred from the condenser to the evaporator 1 via the ammonia liquid transfer pipe 3 is evaporated and transferred to the absorber via the ammonia vapor transfer pipe 2.

During the operation of the refrigeration cycle, the ammonia liquid transferred from the condenser to the evaporator 1 is cooled by the ammonia vapor from the evaporator 1 in the supercooler 4 to improve the thermal efficiency. At the same time, the ammonia liquid that has not been evaporated by the evaporator 1 and contains water is taken out into the ammonia liquid take-out pipe 5 and the inner cylinder 11 of the refrigerant regenerator 6
Here, it is heated by the ammonia liquid from the condenser flowing in the annular space chamber a between the inner cylinder 11 and the outer cylinder 12, and the evaporation of the ammonia and the water is performed, and the regeneration of the refrigerant is performed. Done. The evaporated ammonia vapor and water vapor enter the ammonia vapor transfer pipe 2 and are transferred to the absorber.

In the above-mentioned refrigerant regenerator 6, since the inner diameter of the inlet portion of the inner cylinder 11 is narrowed down to a predetermined height, the heat transfer area per unit area of the inner cylinder in this portion is increased. That is, the heat of the ammonia liquid flowing in the annular space chamber a is efficiently transmitted, and the ammonia liquid and water flowing in the inner cylinder 11 are sufficiently evaporated.
As described above, when the evaporation is actively performed, the air lift function is sufficiently exhibited, so that the ammonia liquid containing water is efficiently extracted from the evaporator 1.

As described above, the inner cylinder 1 in the refrigerant regenerator 6
Since the inner diameter of the inlet portion of the first cylinder 1 is reduced (squeezed), the heat transfer area in the inner cylinder 11 with respect to the flow rate of the liquid passing through the inner cylinder 11 increases. Thus, evaporation is promoted, and the air lift action in this portion is sufficiently exhibited, so that the refrigerant regeneration capacity is increased, and it is possible to cope with an increase in the size of the ammonia absorption refrigerator.

Next, an ammonia absorption refrigerator according to a second embodiment of the present invention will be described with reference to FIG. The difference between the ammonia absorption refrigerator of the second embodiment and that of the first embodiment described above is as follows.
Since it is in the refrigerant regenerator, in this description, only this portion will be described.

That is, as shown in FIG. 2, the lower part of the outer cylinder 12 corresponding to the outer periphery of the inner cylinder 11 whose inner diameter has been reduced over a predetermined height is, similarly to the inner cylinder 11, the upper part of the upper part. smaller than the inner diameter D ₁ (thin) is obtained by the inner diameter D _2.

As described above, the inner diameter of the outer cylinder 12 is also
Since the diameter of the ammonia liquid supplied to the inlet of the outer cylinder 12 is reduced as in the case of the inner cylinder 11, the flow rate of the ammonia liquid increases at this small diameter portion, and the amount of heat applied to the liquid flowing through the inner cylinder 11 increases. And the evaporation of water are performed more efficiently than in the first embodiment. That is, even when the size of the ammonia absorption refrigerator is increased, the air lift function in the refrigerant regenerator is further increased as compared with the first embodiment.

In each of the above embodiments,
It has been described that the orifice 13 is provided at the connection portion of the ammonia liquid extraction pipe 5 to the inner cylinder 11, but the length L of the small diameter portion is further increased, and the pressure loss at the elongated portion is the same as the pressure loss due to the orifice. by it is possible to omit the orifice and the inner diameter of the small diameter portion of the inner cylinder 11, as may be exerted also added throttling by the orifice, into smaller inner diameter d ₃ by the so that,
Orifices can be omitted.

[0022]

As described above, according to the structure of the present invention, the inner diameter of the refrigerant regeneration section on the inlet side of the inner cylinder is reduced, so that the flow rate of the liquid flowing through the inner cylinder is reduced with respect to the heat transfer area of the inner cylinder. As a result, the ammonia liquid containing water flowing in the inner cylinder is sufficiently heated to promote evaporation, and thus the air lift action in this portion is sufficiently exhibited, thereby coping with the enlargement of the ammonia absorption refrigerator. can do.

Further, by reducing the inner diameter of the outer cylinder corresponding to the small diameter portion of the inner cylinder, the flow rate of the ammonia liquid for heating flowing in the outer cylinder is reduced with respect to the flow rate of the ammonia liquid containing water flowing in the inner cylinder. The passage speed is increased, so that the evaporation in the refrigerant regeneration section can be further promoted.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a main configuration of an ammonia absorption refrigerator according to a second embodiment of the present invention.

FIG. 3 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 Ammonia vapor transfer pipe 3 Ammonia liquid transfer pipe 4 Subcooler 5 Ammonia liquid discharge pipe 6 Refrigerant 11 Inner cylinder 12 Outer cylinder 13 Orifice

Continuation of the front page (72) Inventor Takashi Onishi 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Yukio Hiranaka 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Osaka Gas Co., Ltd. (72) Inventor Noboru Tsubakihara 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Osaka Gas Co., Ltd. (72) Inventor Katsuo Iwata 1-10 Fuso-cho, Amagasaki-shi, Hyogo Sumitomo Precision Industries (72) Inventor Masaharu Kodera 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka Hitachi Zosen Corporation (72) Inventor Yu Fujita 1-7-89, Minami-Kohita, Suminoe-ku, Osaka-shi, Osaka No. Hitachi Zosen Corporation (72) Inventor Mitsumi Matsuda 1-7-89 Minami Kohoku, Suminoe-ku, Osaka City, Osaka Prefecture F-term in Hitachi Zosen Corporation 3L093 BB01 BB37 LL05 MM02

Claims (3)

[Claims] An ammonia absorption type having an evaporator for evaporating an ammonia liquid introduced from a condenser through an ammonia liquid transfer pipe and an ammonia vapor transfer pipe for introducing ammonia vapor evaporated by the evaporator to an absorber. In the refrigerator, an ammonia liquid take-out pipe is provided for taking out the ammonia liquid from the lower part of the evaporator and leading the ammonia liquid to the ammonia vapor transfer pipe, and a supercooling section for performing heat exchange between the ammonia vapor transfer pipe and the ammonia liquid transfer pipe. A refrigerant regenerating section for performing heat exchange between the ammonia liquid extracting pipe and the ammonia liquid transferring pipe is provided, and the refrigerant regenerating section is connected to the inner cylinder connected to the ammonia liquid extracting pipe and the ammonia liquid transferring section. With a double pipe structure consisting of an outer cylinder connected to the pipe,
An ammonia absorption refrigerator having a reduced inner diameter on the inlet side of the inner cylinder. 2. The ammonia absorption refrigerator according to claim 1, wherein an orifice is provided near a connection of the ammonia liquid extraction pipe to the inner cylinder in the refrigerant regeneration section. 3. The ammonia absorption refrigerator according to claim 1, wherein the inside diameter of a predetermined portion of the outer cylinder corresponding to the small diameter portion of the inner cylinder in the refrigerant regeneration section is reduced.