JP2002213834A - Absorption refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bleed pipe line which is not influenced by variation of the external temperature and can be readily held in a state close to vacuum. SOLUTION: Refrigerant liquid, pumped out from the lower part of an evaporator 1 by a pump P1, is circulated through a pipe line 30 which extends along a core 25, and sprayed by a spray 1b onto the core 25. The pipe line 30 is branched into a bleed line 24 at a joint 31. The bleed line 24 extends through an absorber 2 along a core 26 and is drawn out of the end of the absorber 2, so as to be connected to a rectifier. Thus the bleed line 24 for supplying the refrigerant liquid from the evaporator to the top part of the rectifying tower is piped, penetrating the absorber 2 in which the pressure is low and the temperature is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigeration apparatus, and more particularly to an absorption refrigeration apparatus capable of maintaining good purity of a refrigerant liquid contained in an evaporator.

[0002]

2. Description of the Related Art In an absorption refrigerating apparatus, an absorbent solution (dilute solution) diluted by absorbing refrigerant vapor in an absorber is sent to a regenerator. The absorbent solution whose refrigerant has been extracted and whose concentration has been increased in the regenerator is returned to the absorber. On the other hand, the refrigerant vapor extracted from the absorbent solution is condensed in the condenser to become a refrigerant liquid and sent to the evaporator. Although the refrigerant liquid sent to the evaporator has a higher purity, a slightly mixed absorbent therein accumulates during a long-term operation, and gradually lowers the purity of the refrigerant liquid in the evaporator. In order to prevent a decrease in the purity of the refrigerant liquid, it is common practice to extract a predetermined amount of the refrigerant liquid in the evaporator and send it to a rectifier.

[0003]

The conduit (bleed tube) for supplying the refrigerant liquid from the evaporator to the rectifier is a relatively small tube because it supplies a small amount of refrigerant. The length is long. Therefore, it is easily affected by the temperature of the arrangement environment, and it is necessary to eliminate the thermal influence from the environment by winding a heat insulating material or the like.

Further, since the environment in which the bleed pipe is piped, that is, the atmosphere, has a relatively higher pressure than the inside of the bleed pipe, it is necessary to maintain the degree of vacuum in the bleed pipe by controlling the bleed pipe at a predetermined leak rate. is there. For example, 50
In order to ensure a pressure of not more than mmHg, it was necessary to devise a joint and to strictly control the leak rate of the bleed tube itself.

[0005] It is an object of the present invention to provide an absorption refrigeration apparatus which can easily manage the thermal influence and the leak rate on the bleed line as described above.

[0006]

SUMMARY OF THE INVENTION The present invention provides an evaporator for containing a refrigerant liquid, an absorber for absorbing refrigerant vapor generated by the evaporator with an absorbent solution, and an absorbent for absorbing the refrigerant liquid. In order to recover, a regenerator for heating the absorbent solution to extract refrigerant vapor, a rectifier for rectifying the refrigerant vapor extracted by the regenerator, and a refrigerant vapor rectified by the rectifier And a condenser that supplies the refrigerant to the evaporator, and a refrigerant liquid in the evaporator is used as a gas-liquid contact liquid in the rectifier, so that a part of the refrigerant liquid is transferred from the evaporator to the rectifier. A bleed line for feeding to an upper portion, wherein the bleed line is piped so as to pass through the inside of the absorber and reach from the evaporator to the rectifier. .

Further, the present invention comprises a sensible heat exchanger for exchanging heat with the outside air and an air-cooling section comprising a cooling fan disposed opposite to the sensible heat exchanger, wherein the regenerator and the rectifier are provided. With the rectifier up, with the regenerator down, placed beside the air-cooling unit, and arranging the absorber on the air-cooling unit, from the inner end of the absorber A second feature resides in that the bleed conduit is provided in the upper part of the rectifier.

[0008] Further, the present invention provides the evaporator, wherein the evaporator is disposed adjacent to a side of the air cooling unit opposite to the regenerator, and passes through the inside of the evaporator. A refrigerant liquid circulation line that circulates the refrigerant liquid in the upper part, wherein the refrigerant liquid circulation line is branched into an evaporator interior spraying means and the bleed line at the upper part of the evaporator. There is a third feature.

According to the first feature, since the bleed line is placed in a low-pressure, stable and relatively high temperature environment in the absorber, the temperature control of the bleed tube is easy and the leak rate is low. Is easy to manage. Moreover, since the temperature of the refrigerant liquid from the evaporator is raised by heat exchange in the absorber and fed to the rectifier, the rectification efficiency is not impaired, and the effect of cooling the absorber is obtained.

Further, according to the second feature, since the refrigerant liquid can be fed from the absorber to the rectifier in a short distance, it is hardly affected by outside air, so that the heat efficiency is good. Further, heat exchange components are compactly arranged around the air cooling unit.

Further, according to the third feature, since the bleed pipe branches off from the spraying means at the upper part in the evaporator, the bleed pipe leading to the inside of the absorber can be shortened.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 2 is a system block diagram showing a main configuration of the absorption refrigeration apparatus according to one embodiment of the present invention. Here, an absorption cooling and heating device is assumed as an embodiment of the absorption refrigeration device. The evaporator 1 contains a fluorinated alcohol such as trifluoroethanol (TFE) as a refrigerant, and the absorber 2 contains dimethylimidazolidinone (DMI) or a derivative thereof as a solution containing an absorbent. The refrigerant is not limited to the fluorinated alcohol, and may be any one that can have a wide non-freezing range. The solution is not limited to the DMI derivative, and can have a wide non-crystalline range.
Any absorbent having a higher normal pressure boiling point than FE and capable of absorbing TFE may be used.

The evaporator 1 and the absorber 2 are fluidly connected to each other via an evaporating (refrigerant) passage (not shown).
When these spaces are kept under a low pressure environment of, for example, about 30 mmHg, the refrigerant in the evaporator 1 evaporates and enters the absorber 2 through the passage. The mist (mist-like refrigerant) remaining in the refrigerant vapor is heated to vaporize, and the condenser 9
Pre-cooler 18 to reduce the temperature of the TFE
Is provided. The absorbent vapor in the absorber 2 absorbs the refrigerant vapor, and the absorption refrigeration operation is performed.

First, when the burner 7 is ignited and the solution concentration in the absorber 2 is increased by the regenerator 3 (the burner, the regenerator and the solution concentration will be described later), the solution in the absorber 2 absorbs the refrigerant vapor. Then, the inside of the evaporator 1 is cooled by the latent heat due to the evaporation of the refrigerant. Inside the evaporator 1, a pipe line 1a through which cold water passes is provided. One end (outlet end in the figure) of the pipeline 1a is connected to the # 1 opening of the first four-way valve V1, and the other end (inlet end in the figure) is connected to the # 1 opening of the second four-way valve V2.

The refrigerant is guided by the pump P1 to the spraying means 1b provided in the evaporator 1, and is sprayed on the pipeline 1a through which the cold water passes. The refrigerant removes the heat of evaporation from the cold water in the pipe 1a to become a refrigerant vapor, and flows into the absorber 2 through the evaporation passage. As a result, the temperature of the cold water in the pipe 1a drops. The refrigerant in the evaporator 1 is guided to the spraying means, and a part of the refrigerant passes through a filter 4 and is supplied to a rectifier 6 as a gas-liquid contact liquid (hereinafter, referred to as “bleed”) as described later. You. A flow control valve V5 is provided between the evaporator 1 and the filter 4. The supply amount of the bleed can be adjusted by controlling the discharge amount of the pump P1, and the opening degree of the flow control valve V5 can be changed (for example,
It is also possible to make a change by this switching. As the cold water flowing through the pipe 1a, it is preferable to use an ethylene glycol or propylene glycol aqueous solution.

When the vapor of the fluorinated alcohol, that is, the refrigerant vapor is absorbed by the solution in the absorber 2, the temperature of the solution increases due to the heat of absorption. The absorption capacity of a solution increases as the temperature of the solution decreases and as the concentration of the solution increases. Therefore, in order to suppress a rise in the temperature of the solution, a pipe 2a is provided inside the absorber 2, and cooling water is passed through the pipe 2a. After passing through the condenser 9 at one end (outlet end in the figure) of the pipe line 2a, the # 4 of the first four-way valve V1 is
The other end (the inlet end in the figure) of the pipeline 2a is connected to the # 2 opening of the second four-way valve V2, respectively. As the cooling water passing through the pipe 2a, the same aqueous solution as the cold water is used.

The solution is guided to the spraying means 2b provided in the absorber 2 by the pump P2, and is sprayed on the pipeline 2a. As a result, the solution is cooled by the cooling water passing through the pipe 2a. On the other hand, the temperature of the cooling water rises because it absorbs heat. The solution in the absorber 2 absorbs the refrigerant vapor, and when the concentration of the absorbent decreases, the absorption capacity decreases. Therefore,
By separating and generating the refrigerant vapor from the absorbent solution in the regenerator 3 and the rectifier 6, the concentration of the solution is increased to recover the absorption capacity.

The solution diluted by absorbing the refrigerant vapor in the absorber 2, that is, the dilute solution, is guided to the spraying means 2 b, and is also fed to the rectifier 6 through the pipe 7 b by the pump P 2 to the regenerator 3. It is made to flow down. The regenerator 3 has a burner 7 for heating the dilute solution supplied from the absorber 2. The burner 7 is preferably a gas burner, but may be any other type of heating means. The solution (concentrated solution) heated by the regenerator 3 to increase the concentration by extracting the refrigerant vapor is returned to the absorber 2 via the pipe 7a. An on-off valve V4 is provided on the pipe 7a, and the concentrated liquid is sprayed on the pipe 2a by the spraying means 2c.

When the rare liquid supplied to the regenerator 3 is heated by the burner 7, refrigerant vapor is generated. This refrigerant vapor is sent to the rectifier 6, where the absorbent solution mixed therein is separated. In this way, the refrigerant vapor having a higher purity is supplied to the condenser 9. The refrigerant that has been cooled and condensed and liquefied in the condenser 9 is sent to the evaporator 1 via the precooler 18 and the pressure reducing valve 11, and is dispersed on the pipeline 1a.

Although the purity of the refrigerant supplied from the condenser 9 to the evaporator 1 is extremely high, an extremely small amount of the absorbent component is mixed. It is inevitable that the absorbent component accumulates over a long operation cycle and the purity of the refrigerant in the evaporator 1 gradually decreases. Therefore, as described above, only a small part of the refrigerant is supplied from the evaporator 1 to the rectifier 6 via the filter 4 so as to pass through a cycle for increasing the purity again together with the refrigerant vapor generated from the regenerator 3. ing.

The high-temperature concentrated liquid in the pipe 7a discharged from the regenerator 3 is discharged from the absorber 2 by the heat exchanger 12 provided in the middle of the pipe connecting the absorber 2 and the rectifier 6. After being cooled by exchanging heat with the dilute solution, it is collected in the absorber 2. On the other hand, the diluted liquid preliminarily heated in the heat exchanger 12 is supplied to the regenerator 3. Although the thermal efficiency is improved in this way, the heat of the concentrated liquid refluxed is further transferred to the absorber 2 or the condenser 9.
The heat exchanger (not shown) for transmitting to the cooling water in the pipe line 2a exiting from the water is provided, so that the temperature of the concentrated liquid refluxed to the absorber 2 is further reduced, and the cooling water temperature is further reduced. A configuration that can be raised may be adopted.

A pipe 4a is passed through the chilled water or a sensible heat exchanger 14 for exchanging heat between the chilled water and the outside air.
5 is provided with a conduit 3a. One end (the inlet end in the figure) of each of the conduits 3a, 4a is the opening # 3, 4 of the first four-way valve V1, and the other end (the outlet end, the opening) is the opening # 3, 4 of the second four-way valve V2. Respectively. The indoor unit 15 is provided in a room that performs cooling and heating, and is provided with a cooling air or warm air blowing fan (both are common) 10 and a blowing outlet (not shown). The sensible heat exchanger 14 is placed outdoors, and the fan 19 forcibly exchanges heat with the outside air.

The evaporator 1 has a level sensor L1 for detecting the amount of the refrigerant and a temperature sensor T1 for detecting the temperature of the refrigerant.
Is provided. The absorber 2 is provided with a level sensor L2 for sensing the amount of the solution. The condenser 9 is provided with a level sensor L9 for detecting the amount of condensed refrigerant, a temperature sensor T9 for detecting the temperature of the refrigerant, and a pressure sensor PS9 for detecting the pressure in the condenser 9.

The sensible heat exchanger 14 has a temperature sensor T14 for sensing the outside air temperature, the indoor unit 15 has a temperature sensor T15 for sensing the temperature of the room to be cooled and heated, and the regenerator 3 senses the temperature of the solution. Temperature sensors T3 are provided. Further, a temperature sensor T6 is provided at the top of the rectifier 6 to sense the internal temperature of the rectifier 6, that is, the temperature of the refrigerant vapor rectified by the rectifier 6 (tower top temperature).

During the cooling operation, the first and second four-way valves V1 and V2 are switched to positions where the # 1 and # 3 openings are respectively connected and the # 2 and # 4 openings are connected. Thereby, the cold water whose temperature has been lowered by the refrigerant being sprayed on the pipeline 1a is guided to the pipeline 3a of the indoor unit 15 to cool the room.

During the heating operation, the first and second four-way valves V1 and V2 are switched to positions where the # 1 and # 4 openings are respectively connected and the # 2 and # 3 openings are connected. Thereby, the warmed cooling water in the pipeline 2a is guided to the pipeline 3a of the indoor unit 15 to heat the room.

If the outside air temperature becomes extremely low during the heating operation, it becomes difficult to pump heat from the outside air through the sensible heat exchanger 14, and the heating capacity is reduced. For such a case,
A reflux passage 9a and an on-off valve 17 are provided to bypass between the condenser 9 and the regenerator 3 (or the rectifier 6). Thus, when it is difficult to pump heat from the outside air, the absorption refrigeration cycle operation is stopped, the steam generated in the regenerator 3 is circulated between the condenser 9 and the heat generated by the burner 7 and the heat generated in the Thus, the temperature of the cooling water is increased by a direct fired operation in which the cooling water is efficiently transmitted to the cooling water in the pipe line 2a to improve the heating capacity.

The concentration of the dilute solution fed from the absorber 2 to the regenerator 3 changes depending on the outside air condition and the load condition. Therefore, in order to maintain the purity of the refrigerant vapor at the top of the rectifier 6 well and to maintain the purity of the refrigerant liquid supplied to the evaporator 1 at a high level, the purity of the refrigerant is changed along with the concentration of the diluted liquid. It is necessary to change the amount of bleed supplied to the retainer 6. Therefore, the discharge amount of the pump P1 can be controlled based on the tower top temperature of the rectifier 6 by the temperature sensor T6, and the bleed supply amount can be adjusted. Regarding bleed supply control,
The description of JP-A-2000-55503 is incorporated herein by reference, and a detailed description thereof will be omitted.

FIG. 3 is a perspective view of the absorption type air conditioner, showing a state in which a cover is partially removed so that the arrangement of the main part can be observed. 2, the same reference numerals as those in FIG. 2 denote the same parts, and only the main parts of the support members and the piping are illustrated. This absorption type cooling and heating device has a substantially rectangular parallelepiped shape as a whole, and a fan 19 having an axis extending in the directions F and B indicated by arrows A, that is, in the front-back direction of the chassis 20, is disposed in the center of the rectangular parallelepiped housing 20. . The sensible heat exchanger 14 is located behind the fan 19, that is,
Are arranged (not shown). The periphery of the fan 19 is surrounded by a cylindrical air guide 21 for guiding the wind from the fan 19 to the sensible heat exchanger 14.

A regenerator 3 is arranged at the lower part on the right side (R direction indicated by an arrow A) of the housing 20. Above the regenerator 3, a cylindrical rectification extending upward along the right wall surface of the housing. The vessel 6 is arranged. A heat exchanger 12 is tied to the rectifier 6.

On the other hand, the evaporator 1 is vertically arranged on the wall surface on the left side (L direction indicated by an arrow) of the housing 20. Evaporator 1
Above the evaporator 1, an absorber 2 is disposed so as to lie adjacent to the upper part of the evaporator 1 and extends from the evaporator 1 toward the right side of the housing 20. Above the absorber 2, that is, in the vicinity of the upper surface of the housing 20, the condenser 9 is disposed horizontally long along the absorber 2.

The top of the rectifier 6 and the right end of the condenser 9 are used to introduce refrigerant vapor from the rectifier 6 to the condenser 9.
They are connected to each other by a connecting pipe 23. A conduit (bleed tube) 24 for feeding the refrigerant liquid as bleed from the evaporator 1 to the top of the rectifier 6 passes through the interior of the absorber 2 and extends from the right end of the absorber 2 It protrudes and is connected to the rectifier 6.

A pump P3 for circulating cooling water is provided at the lower left portion of the housing 20. The pump P4 is disposed behind the pump P3. Further, a pump P1 for circulating the solution is disposed below the evaporator 1. A conduit 30 drawn from the pump P1 passes through the inside of the evaporator 1 and extends upward.
4 is connected. As described above, the fan 19 and the sensible heat exchanger 14 are arranged at the center, and the main components are compactly accommodated in the space between the fan 19 and the wall surface of the housing 20.

FIG. 4 shows an evaporator 1, an absorber 2 and a condenser 9
Is a view (rear view) as viewed from the back side, that is, the side B of the arrow A. FIG. 1 is a perspective view of the evaporator 1 and the absorber 2 and shows a state where a cover is removed. In both figures, the evaporator 1, the absorber 2 and the condenser 9 are provided with heat exchange cores 25, 26 and 27. Core 25,
26 and 27 are formed by arranging a large number of thin plates, and a cooling water pipe is provided through the thin plates. These cores 25,
26, 27, the inlets 251,
61, 271 and outlets 252, 262, 272 are provided to protrude. Above the core 25 of the evaporator 24, a spraying means or a spray 1 for recirculating the refrigerant.
a spraying means for recirculating the solution, that is, a spray 2b, and a spraying means 2 for spraying the concentrated liquid circulating from the regenerator 2 onto the core 26 above the absorber 2.
c is provided.

A pump P1 is connected to the solution outlet 28 of the evaporator 1, and a conduit 30 connected to the outlet 29 of the pump P1.
Extends upward along the core 25 to form the joint 3 for branching.
Connected to 1. Conduit 30 branched at joint 31
One is connected to the spray 1b and the other is a bleed tube 2
4, extends through the absorber 2 along the core 26 to the end of the absorber 2 and to the top of the rectifier 6 as described with reference to FIG.

A pump P2 is arranged on the side of the evaporator 1, and a conduit 32 for introducing a solution from the absorber 2 is connected to an inlet of the pump P2. The outlet of the pump P2 is connected to an upwardly extending conduit 33 which branches at a joint 34 into the spray 2b side and a conduit 35 which is part of the conduit 7b extending to the heat exchanger 12.

A precooler 18 is provided between the evaporator 1 and the absorber 2. A conduit 36 for feeding the refrigerant liquid from the condenser 9 passes through the absorber 2 and is connected to the precooler 18.
Further, a conduit 37 connected to the outlet side of the precooler 18 extends over the core 25 of the evaporator 1 via the pressure reducing valve 11 and guides the refrigerant liquid into the evaporator 1.

[0038]

According to the present invention, since the bleed conduit is placed in a stable temperature environment inside the absorber, there is no need to take measures against heat influence from the external environment, such as winding a heat insulating material. In addition, since the refrigerant liquid undergoes heat exchange in a relatively high temperature atmosphere in the absorber and rises in temperature, there is also a cooling effect of the absorber. Further, the bleed line is, for example, 10 mmHg to 3 mm.
Since the piping is provided in the absorber in a low-pressure environment of 0 mmHg, it is easy to hold the piping in a state close to vacuum.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of a cooling and heating device according to an embodiment of the present invention.

FIG. 2 is a system block diagram illustrating a configuration of a cooling and heating device according to an embodiment of the present invention.

FIG. 3 is a perspective view of a cooling and heating device according to the embodiment of the present invention.

FIG. 4 is a main part rear view of the cooling and heating device according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Evaporator, 1a ... Pipe for cold water, 2 ... Absorber, 2
a: cooling water pipe 3: regenerator, 4: filter, 6
... rectifier, 9 ... condenser, 12 ... heat exchanger, 14 ... sensible heat exchanger, 19 ... fan, 20 ... housing, 21 ... air guideway, 23 ... connecting pipe, 24 ... bleed pipe, 25,
26, 27 ... core, 28 ... solution outlet

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsuyoshi Muto 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3L093 AA02 BB01 BB22 DD06 GG02 HH12 LL01 LL11 MM03 MM07

Claims (3)

[Claims] 1. An evaporator for containing a refrigerant liquid, an absorber for absorbing refrigerant vapor generated by the evaporator with an absorbent solution, and the absorbent solution for recovering the absorbent concentration of the absorbent solution. A rectifier that heats and extracts a refrigerant vapor, a rectifier that rectifies the refrigerant vapor extracted by the regenerator, and a refrigerant vapor rectified by the rectifier to condense to the evaporator. A condenser to be supplied; and a bleed line for feeding a part of the refrigerant liquid from the evaporator to the upper part of the rectifier in order to use the refrigerant liquid in the evaporator as a gas-liquid contact liquid in the rectifier. Wherein the bleed conduit is provided so as to pass through the interior of the absorber and reach from the evaporator to the rectifier. 2. A sensible heat exchanger for exchanging heat with outside air, and an air cooling unit including a cooling fan disposed opposite to the sensible heat exchanger, wherein the regenerator and the rectifier are rectified. With the vessel up and the regenerator down, placed on the side of the air-cooling section, the absorber is placed on the air-cooling section, and the rectifier 2. The absorption refrigeration system according to claim 1, wherein said bleed conduit is provided in an upper portion of the inside. 3. The evaporator is disposed adjacent to a side of the air-cooling unit opposite to the regenerator, and passes through the inside of the evaporator to allow a refrigerant liquid in the evaporator to pass therethrough. A refrigerant liquid circulation line for circulating the refrigerant to the upper part, wherein the refrigerant liquid circulation line is branched at an upper part inside the evaporator into a means for spraying the inside of the evaporator and the bleed line. Item 3. An absorption refrigeration apparatus according to Item 2.