JPH0321825B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an absorption refrigerating machine (hereinafter referred to as an absorption chiller) that utilizes an absorption refrigeration cycle and is used for making chilled water for air conditioning, making ice, or for heat pumps.

The absorption chiller that has been commonly used for a long time is
As shown in FIG.
The refrigerant body 5 is provided between the absorber 3 and the absorber 3, and has a structure in which the refrigerant vaporized in the evaporator 2 is absorbed by the absorption liquid flowing down the surface of the heat exchanger 4 of the absorber. The absorber 3 and the evaporator 2 each have a group of heat transfer tubes to form heat exchangers 4 and 6, and the refrigerant gas vaporized in the evaporator 2 flows laterally into the absorber 3 and is absorbed. The absorption efficiency of the absorber 3, the relationship between the absorption liquid concentration and the temperature gradient, etc., were not particularly considered.

The structure of conventional absorption chillers like this does not pose a problem in combinations of refrigerant and absorbent where the vapor pressure of the absorbent is extremely low, such as absorption chillers using a water-lithium halide absorption refrigeration cycle. Absorption coolers that use organic absorbents, for example, the combination of refrigerant and absorbent is Freon 22-tetraethylene glycol dimethyl ether,
In the case of the TFE (trichloroethanol)-N-methyl-2-pyrrolidone system, not only does the absorbent move into the refrigerant vapor as a mixed flow, but also the absorbent evaporates. That is, when the above-mentioned organic absorbent is used, not only is the refrigerant absorbed into the absorption liquid, but as the refrigerant is absorbed in the absorber, the absorbent vaporizes and changes into a vapor phase.

The present invention, which has been made in consideration of these points, has a structure in which the evaporator and absorber are communicated at the lower part so that the vapor composition in each cross section in the absorber of an absorption chiller approaches an equilibrium state with the absorption liquid concentration. The refrigerant gas vaporized in the evaporator flows from the bottom of the absorber to the top of the absorber.The main purpose of this is to improve the absorption efficiency of refrigerant in the absorber. It is something.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In Fig. 2, 7 has a combustion device 8 for kerosene, gas, etc., which heats and boils an absorption liquid that has absorbed a large amount of refrigerant (hereinafter referred to as concentrated liquid) to gasify and separate the refrigerant. 9 is a rectifier for separating the absorbent components from the rising refrigerant gas; 10 is a rectifier for cooling the gas stream sent from the rectifier 9 with a heat exchanger 11 for final separation of the absorbent components; The liquid separated in the dephlegmator 10 is led to the liquid dispersion device 12, and is dispersed from the upper part of the rectifier 9 to form a gas-liquid for separating the refrigerant and the absorbent. Used as part of the contact liquid. 13
17 is an evaporator which incorporates a heat exchanger 14 with a pipe wound in a helical shape, and which vaporizes the liquid refrigerant whose pressure is lowered by a pressure reducing valve 15 and is sprayed from a sprayer 16; The absorption liquid (hereinafter referred to as diluted liquid) with a low refrigerant concentration is depressurized by the pressure reducing valve 18 and sprayed from above, thereby absorbing the refrigerant gas vaporized in the evaporator 13. This causes the evaporator 13 to reach a low temperature level. This is an absorber that continuously absorbs heat from a heat source fluid, and the evaporator 13 and absorber 17 are communicated with each other through an opening 18 at the bottom, and the absorber 17 is located outside or inside the evaporator 13. It has a concentric arrangement. 19 is absorber 1
7 is a solution pump that returns the concentrated liquid that has absorbed the refrigerant to the generator 7, and the concentrated liquid pipe 20 having the solution pump 19 is connected to a heat exchanger 21 that cools the inside of the dephlegmator 10, and from the generator 7 A heat exchanger 22 is provided that exchanges heat with the dilute liquid sent to the absorber 17 to preheat the concentrated liquid.

Further, the rectifier 9 is surrounded by a heat insulating material 23, and a generator 13 and an absorber 1 are arranged on the outside thereof.
7 and is thermally separated from the dispersion device 12 inside.
The concentrating section 25 includes a filler that brings the liquid sprayed by the generator 7 into gas-liquid contact with the gas flow flowing from the generator 7 toward the condenser 24, and the concentrator 25 includes a filler that also promotes gas-liquid contact between the gas flow and the concentrated liquid. The collection part 26 containing the liquid is vertically installed, and the liquid that has fallen between the filling materials in the concentrating part 25 flows down the collection part 26 together with the concentrated liquid that is sprayed on the filling materials by the sprayer 27. and returns to the generator 7.

Furthermore, the absorber 17 and the condenser 24 have built-in heat exchangers 28 and 29 formed in a coil shape that goes around the rectifier 9, and water or brine is supplied to the heat exchangers 28 and 29 as indicated by the dashed-dotted line arrow. By distributing the heat in the absorber 7 and condenser 24, the heat in the absorber 7 and condenser 24 can be discharged outside the machine (used in the case of a heat pump). The vessel 11 has a cooling function for the dephlegmator 10.

In the above configuration, the refrigerant gas regenerated by the generator 7 comes into contact with the concentrated liquid flowing down in the recovery section 26 at the lower stage of the rectifier, and then comes into contact with the reflux liquid condensed in the demultiplexer 10 in the concentration section 25. After being brought into contact and having its absorbed liquid components reduced, it is guided from the dephlegmator 10 to the condenser 24 . In the condenser 24 , the refrigerant gas is condensed by the heat exchanger 29 , the liquefied refrigerant is sprayed from the upper part of the evaporator 13 , and the refrigerant gas that has been vaporized by obtaining heat from the heat source fluid is transferred to the evaporator 13 and the absorber 17 . It flows from below into the absorber 17 through the opening 18 at the bottom of the partition wall between the absorbent liquid and the absorbent liquid, and is absorbed by the absorbent liquid while forming a concentration gradient and a temperature gradient.

The absorption liquid (concentrated liquid) that has absorbed the refrigerant is sucked into the solution pump 19 from the bottom of the absorber 17, heated by the heat exchanger 21 of the dephlegmator, and passed through the absorption liquid heat exchanger 22 to the rectifier 9. The diluted liquid from which the refrigerant has been separated in the generator 7 is passed through the disperser 27 between the concentrating section 25 and the recovery section 26 and refluxed to the generator 7. 17 sprayers 30.

If chilled water or brine from the load is circulated through the heat exchanger 14 of an absorption chiller that has a closed circulation cycle of refrigerant and absorption liquid as shown by the solid line arrow, this absorption chiller can be used as an air conditioner or a refrigerator. This absorption chiller can be used as a heat pump by supplying the heat source fluid to the heat exchanger 14 and circulating the fluid supplied to the load through the circuit of the heat exchangers 28, 29, and 11. .

Therefore, in the absorption chiller of the present invention, as described above, the evaporator and absorber are connected at the lower part,
The structure is such that refrigerant gas vaporized in the evaporator flows from the bottom to the top of the absorber, and the refrigerant gas is absorbed by the absorption liquid flowing down from the top of the absorber, so that the vapor composition in each cross section in the absorber is can be brought close to equilibrium with the absorption liquid concentration.

In other words, when the absorption liquid sprayed in the absorber flows down while absorbing refrigerant gas, the absorption liquid concentration and vapor concentration of this absorption liquid both increase as it absorbs the refrigerant, and the concentration decreases as it absorbs the refrigerant. It will increase. On the other hand, when refrigerant gas flows from below to above the absorber, the amount of refrigerant gas is large at the bottom of the absorber and decreases as it goes upwards. A similar increase/decrease trend can be provided in each cross section of the vessel. In other words, in each part of the absorber, a pseudo-equilibrium state is created between the refrigerant gas concentration and the vapor concentration of the absorption liquid, so that the increasing concentration of refrigerant gas does not deviate greatly from the vapor concentration of the absorption liquid. Even in absorption refrigerating machines that use a refrigerant-based absorbent and may be accompanied by vaporization of the absorbent, it is possible to form an absorption mechanism that suppresses the generation of vapor from the absorbent, making it possible to improve refrigerant absorption efficiency. It is.

Furthermore, since the refrigerant gas flowing from the bottom of the absorber has a low temperature and the absorption liquid flowing down from the top has a high temperature, if the refrigerant gas and the absorption liquid are brought into contact with each other in counterflow as in the present invention, , inside the absorber, a temperature gradient can be formed in which the temperature gradually decreases from the top to the bottom, and by forming such a temperature gradient, the evaporation of the absorption liquid is suppressed and the refrigerant is absorbed. It is possible to improve efficiency, and it is possible to provide a smaller absorber with the same absorption capacity.

In addition, the formation of such a temperature gradient in the absorber is particularly preferable when operating the absorption chiller as a heat pump. By recirculating the concentrated liquid in the lower part of the absorber into the absorber, heat pump operation with a high temperature rise can be realized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an absorption evaporator cylinder of a conventional absorption chiller, and FIG. 2 is a cycle block diagram showing an embodiment of the absorption chiller according to the present invention. 7... Generator, 9... Rectifier, 13... Evaporator, 17... Absorber, 18... Opening.

Claims (1)

[Claims] 1. A generator that separates the absorbent component from the gas stream heated and vaporized by the generator to obtain a refrigerant gas stream, a condenser that cools and liquefies the refrigerant gas, and a condenser that obtains heat from the fluid outside the machine and converts it into a liquid refrigerant. An evaporator that vaporizes the refrigerant, and an absorber that absorbs the vaporized refrigerant by dispersing an absorption liquid in which the refrigerant is separated and the refrigerant components are reduced in the generator, and these generators, condensers,
In a refrigerant-absorbent circulation cycle in which an evaporator and an absorber are connected with airtight piping, the evaporator and absorber are arranged to communicate at the bottom, and the refrigerant gas vaporized in the evaporator is An absorption chiller characterized by being configured such that the flow flows from the bottom to the top of the absorber.