JPS6125986B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-stage absorption refrigerator that can obtain cold water using a relatively low temperature heat source.

Two-stage absorption refrigerators are used to obtain cold water by effectively utilizing a relatively low-temperature heat source, such as 100°C or less. As shown in Figure 2, this two-stage absorption refrigerator consists of two cycles A and B on the vapor pressure diagram of the absorption liquid, and in the intermediate stage connecting these two cycles, there is a low-pressure side cycle I. The steam generated in the regenerator is absorbed by the absorber in the high-pressure cycle. That is, as shown in FIG. 1, this two-stage absorption refrigerator has an evaporator 1 in which the fluid to be cooled gives heat of evaporation to the refrigerant and becomes cold water.
, an absorber 2 that absorbs the refrigerant evaporated and vaporized in the evaporator 1 into an absorption liquid, an intermediate regenerator 3 that heats the dilute absorption liquid that has absorbed the refrigerant in the absorber 2, and evaporates the refrigerant; An intermediate absorber 4 that absorbs the refrigerant evaporated and vaporized in the regenerator 3 into an absorption liquid, a regenerator 5 that heats the dilute absorption liquid that has absorbed the refrigerant in the intermediate absorber 4, and evaporates the refrigerant, and a regenerator. and a condenser 6 for cooling and condensing the refrigerant evaporated in step 5. In addition, 7 and 8 are heat exchangers provided in the middle of the movement route of the low-pressure side and high-pressure side absorption liquid, respectively. Therefore, the above configuration requires an extra intermediate regenerator and intermediate absorber compared to a normal absorption refrigerator, which has the disadvantage of increasing costs and complicating the system.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a two-stage absorption refrigerator that can eliminate the above-mentioned drawbacks.

That is, the present invention provides an evaporator that absorbs heat from a fluid to be cooled and cools it to evaporate a refrigerant, an absorber and an intermediate absorber that absorb the evaporated refrigerant into an absorption liquid, and a dilute absorption liquid that absorbs the refrigerant. A regenerator for obtaining a concentrated absorption liquid by evaporating the refrigerant from the refrigerant, and a condenser for condensing the evaporated refrigerant are provided, and the absorption liquid is distributed over the absorber, the intermediate absorber, and the regenerator in any order. Provide an absorption liquid circulation path to circulate,
A part of the refrigerant condensed in the condenser is guided to the evaporator, and the remaining refrigerant is heated and evaporated by the heat of absorption generated in the absorber and guided to the intermediate absorber. It is a stage absorption refrigerator.

According to this configuration, it is possible to eliminate the need for an intermediate regenerator while maintaining the capability of a conventional two-stage absorption refrigerator.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. 11 is an evaporator that evaporates refrigerant (e.g. water) A, 12 is an absorber that absorbs the evaporated refrigerant into an absorption liquid (e.g. lithium bromide), 13 is also an intermediate absorber, and 14 is a dilute absorber that absorbs the refrigerant. A regenerator 15 heats the liquid B1 to evaporate its refrigerant to obtain a concentrated absorption liquid B2, and a condenser 15 cools and condenses the evaporated refrigerant. A cooled pipe 16 through which a cooled fluid (for example, water) C flows is inserted into the evaporator 11, and
A cooling pipe 17 through which a cooling fluid (e.g., cooling water) D flows is inserted into the intermediate absorber 13, and a heating pipe 18 through which a heating fluid (e.g., waste hot water) E flows is provided in the regenerator 14. A cooling pipe 19 through which a cooling fluid D flows is inserted into the condenser 15 . Note that 20 is a refrigerant circulation pipe that circulates refrigerant within the evaporator 11. and,
The absorbent liquid is configured to circulate through the absorber 12, the regenerator 14, and the intermediate absorber 13 in this order. That is, the regenerator 14 and the intermediate absorber 13 are connected to a concentrated absorption liquid transfer pipe (hereinafter simply referred to as a concentrated absorption liquid pipe) 21.
The intermediate absorber 13 and the absorber 12 are connected by an intermediate (concentration) absorption liquid transfer pipe (hereinafter simply referred to as the intermediate absorption liquid pipe) 22, and the absorber 12 and the regenerator 14 are connected by a dilute absorption liquid transfer pipe 22. They are connected through a liquid transfer pipe (hereinafter simply referred to as a dilute absorption liquid pipe) 23. Further, a part of the refrigerant condensed in the condenser 15 is guided to the evaporator 11, and the remaining refrigerant is once heated and evaporated in the absorber 12, and then transferred to the intermediate absorber 13.
guided by. That is, the condenser 15 and the refrigerant circulation pipe 20 of the evaporator 11 are connected by the first refrigerant transfer pipe 24, and the condenser 15 and the absorber 12 are branched from the first refrigerant transfer pipe 24. They are connected by a second refrigerant transfer pipe 25, and further, the absorber 12 and intermediate absorber 13 are connected by a refrigerant vapor transfer pipe 26. Note that between the dilute absorption liquid pipe 23 and the intermediate absorption liquid pipe 22, between the dilute absorption liquid pipe 23 and the first refrigerant transfer pipe 24, and between the dilute absorption liquid pipe 23 and the concentrated absorption liquid pipe 21. are the heat exchanger 27,
28 and 29 are interposed to achieve heat recovery. Further, pumps 30 to 34 are installed in the refrigerant circulation pipe 20, the concentrated absorption liquid pipe 21, the intermediate absorption liquid pipe 22, the dilute absorption liquid pipe 23, and the first refrigerant transfer pipe 24, respectively.

Next, the cooling effect will be explained. Evaporator 11
The fluid C to be cooled flowing through the pipe 16 to be cooled is cooled by evaporation of the refrigerant in the evaporator 11 .
On the other hand, the refrigerant A evaporated in the evaporator 11 is absorbed by the absorption liquid in the absorber 12, and the dilute absorption liquid B1 that has absorbed this refrigerant is led to the regenerator 14 via the dilute absorption liquid pipe 23. This dilute absorption liquid is heated by the heating fluid E flowing through the heating tube 18 in the regenerator 14, and the absorbed refrigerant is evaporated. The concentrated absorption liquid B2 regenerated by the regenerator 14 is guided to the intermediate absorber 13 via the concentrated absorption liquid pipe 21, where it is passed through the condenser 1.
5 and while passing through the absorber 12,
The evaporated refrigerant is absorbed by the absorption heat generated within the absorber 12. The intermediate absorption liquid B3 that has absorbed the refrigerant in the intermediate absorber 13 reaches the absorber 12 via the intermediate absorption liquid pipe 22, where it absorbs the refrigerant from the evaporator 11. When the above absorption liquid cycle is expressed as a vapor pressure diagram, it becomes as shown in FIG. 4. In this way, the absorption liquid is transferred to the regenerator 14 and the intermediate absorber 13.
The absorbers 12 and 12 are circulated in series, and the refrigerant entering the intermediate absorber 13 is evaporated using the absorption heat in the absorber 12, so the intermediate regenerator retains the conventional two-stage absorption function. can be made unnecessary.

Next, another embodiment will be explained based on FIGS. 5 and 6. In the above embodiment, the absorption liquid is transferred from the regenerator 14 → intermediate absorber 13 → absorber 12 →
While the absorbent liquid was circulated in the order of the regenerator 14, in other embodiments, the absorbent liquid was circulated in the order of the regenerator 14 → absorber 12 → intermediate absorber 13 → regenerator 14. ing. That is,
The concentrated absorption liquid B2 regenerated by the regenerator 14 is guided to the absorber 12 via the concentrated absorption liquid pipe 21, and the concentrated absorption liquid introduced into the absorber 12 absorbs the refrigerant from the evaporator 11. This intermediate absorption liquid B3 is led to the intermediate absorber 13 via the intermediate absorption liquid pipe 22, where the intermediate absorption liquid is further mixed with the refrigerant sent through the refrigerant vapor transfer pipe 26. This diluted absorption liquid B1 is returned to the regenerator 14 via the diluted absorption liquid pipe 23. In addition, in the above configuration, the heat exchanger 3 for heat recovery
Two numbers 5 and 36 are provided. Further, FIG. 6 shows the cycle of the above-mentioned absorption liquid.

[Brief explanation of the drawing]

Figures 1 and 2 show conventional examples.
The figure is a flow sheet diagram, Figure 2 is a diagram showing the absorption liquid cycle, Figures 3 and 4 show an embodiment of the present invention, Figure 3 is a flow sheet diagram, and Figure 4 is a diagram showing the absorption liquid cycle. Figures 5 and 6 showing the liquid cycle show other embodiments. Figure 5 is a flow sheet diagram, and Figure 6 is a diagram showing the absorption liquid cycle. 11... Evaporator, 12... Absorber, 13... Intermediate absorber, 14... Regenerator, 15... Condenser, 2
0... Refrigerant circulation pipe, 21... Concentrated absorption liquid transfer pipe, 2
2...Intermediate absorption liquid transfer pipe, 23...Dilute absorption liquid transfer pipe, 24...First refrigerant transfer pipe, 25...Second refrigerant transfer pipe, 26...Refrigerant vapor transfer pipe.

Claims (1)

[Claims] 1. An evaporator that extracts heat from the fluid to be cooled and cools it to evaporate the refrigerant, an absorber and an intermediate absorber that absorb the evaporated refrigerant into an absorption liquid, and an evaporator that evaporates the refrigerant from the dilute absorption liquid that has absorbed the refrigerant. An absorption liquid that is provided with a regenerator that obtains a concentrated absorption liquid and a condenser that condenses the evaporated refrigerant, and that circulates the absorption liquid through the absorber, intermediate absorber, and regenerator in any order. A circulation path is provided so that a part of the refrigerant condensed in the condenser is guided to the evaporator, and the remaining refrigerant is heated and evaporated by the absorption heat generated in the absorber and guided to the intermediate absorber. A two-stage absorption refrigerator featuring: