CN215002363U

CN215002363U - Absorption refrigerator

Info

Publication number: CN215002363U
Application number: CN202120600914.7U
Authority: CN
Inventors: 青山淳
Original assignee: Ebara Refrigeration Equipment and Systems Co Ltd
Current assignee: Ebara Refrigeration Equipment and Systems Co Ltd
Priority date: 2020-04-09
Filing date: 2021-03-24
Publication date: 2021-12-03
Anticipated expiration: 2031-03-24
Also published as: JP2021167684A; CN113513857A

Abstract

The utility model provides an absorption refrigerator which simplifies the structure of the driving liquid of a cooling and air-extracting device. An absorption refrigerator (1) is provided with: an evaporator (20) which has a fluid to be cooled (21) in which a fluid to be cooled (C) flows, and which removes latent heat of evaporation necessary for evaporating a refrigerant liquid (Vf) into a refrigerant vapor (Ve) from the fluid to be cooled flowing through the fluid to be cooled (C) and cools the fluid to be cooled; an absorber (10) that introduces the refrigerant vapor generated in the evaporator (20) and absorbs the absorption liquid (Sa); an air extraction device (51) for extracting the non-condensable gas (Ng) in the absorber (10), and configured to introduce and pass the absorption liquid (S) in the absorber (10) as a driving liquid (Sd) to suck the non-condensable gas (Ng); and a driving liquid cooling unit (52) for cooling the driving liquid (Sd) introduced into the air-extracting device (51) by means of the refrigerant (V) of the evaporator (20).

Description

Absorption refrigerator

Technical Field

The present invention relates to an absorption refrigerator, and more particularly to an absorption refrigerator having a simplified structure of a driving liquid of a cooling and air-extracting device.

Background

In an absorption refrigerator that cools cold water by an absorption refrigeration cycle of an absorption liquid and a refrigerant, if a non-condensable gas such as hydrogen gas is generated in the absorption refrigerator or the non-condensable gas enters the absorption refrigerator from the outside, the refrigerating capacity is reduced and the inside is corroded, and therefore an ejector is used to extract the non-condensable gas (for example, see patent document 1). The ejector described in patent document 1 introduces a part of the dilute solution sent from the absorber to the regenerator as a driving fluid. On the other hand, in an absorption heat pump having a structure similar to that of an absorption refrigerator, a cooling unit for cooling a driving fluid is provided in order to reduce the vapor pressure of the driving fluid and improve the air extraction capacity (for example, see patent document 2).

Patent document 1: japanese laid-open patent publication No. 11-118301

Patent document 2: japanese laid-open patent publication No. 2007-147148

The cooling unit described in patent document 2 uses external cooling water to cool the driving fluid, and requires a separate heat exchanger for cooling the external cooling water and the driving fluid.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, an object of the present invention is to provide an absorption refrigerator having a simplified structure for cooling a driving liquid of an air extractor for extracting a non-condensable gas.

In order to achieve the above object, an absorption refrigerator according to a first embodiment of the present invention, for example, as shown in fig. 1, includes: an evaporator 20 that has a cooling target fluid flow path 21 in which a cooling target fluid C flows, and cools the cooling target fluid C by taking latent heat of evaporation necessary for evaporating a refrigerant liquid Vf, which is a liquid of a refrigerant V, from the cooling target fluid C flowing through the cooling target fluid flow path 21 to turn into a refrigerant vapor Ve, which is a vapor of the refrigerant V; an absorber 10 that introduces the refrigerant vapor Ve generated in the evaporator 20 and absorbs the absorption liquid Sa; an air extractor 51 for extracting the non-condensable gas Ng in the absorber 10, and configured to introduce and pass the absorbing liquid S in the absorber 10 as a driving liquid Sd to suck the non-condensable gas Ng; and a driving liquid cooling unit 52 for cooling the driving liquid Sd introduced into the air-extracting device 51 by the refrigerant V of the evaporator 20.

With this configuration, the refrigerant in the absorption refrigerator cools the drive liquid, so that a heat exchanger for exchanging heat with an external cooling fluid is not required, and the apparatus configuration can be simplified.

In addition, in the absorption refrigerator 1 according to the first embodiment of the present invention, as shown in fig. 1, for example, the driving liquid cooling unit 52 is disposed inside the evaporator 20.

With this configuration, the device configuration can be further simplified.

In addition, in the absorption refrigerator 1 according to the first embodiment of the present invention, for example, as shown in fig. 1, the evaporator 20 includes the refrigerant liquid spraying device 22 that sprays the refrigerant liquid Vf toward the cooling target fluid flow path 21, and the driving liquid cooling unit 52 is disposed at a position where the refrigerant liquid Vf sprayed from the refrigerant liquid spraying device 22 can come into contact with.

With this configuration, the driving liquid in the driving liquid cooling portion can be cooled by latent heat of evaporation of the sprayed refrigerant liquid.

In addition, in the absorption refrigerator according to the fourth embodiment of the present invention, for example, as shown in fig. 1, in the absorption refrigerator according to the second or third embodiment of the present invention, the driving liquid cooling portion 52 is disposed between the minimum level and the maximum level of the refrigerant liquid Vf in the evaporator 20.

With this configuration, when the refrigerant level inside the evaporator is low at the time of low load of the absorption chiller, the driving liquid inside the driving liquid cooling unit can be cooled by the latent heat of evaporation of the refrigerant liquid, and when the refrigerant level inside the evaporator is high at the time of high load of the absorption chiller, the driving liquid inside the driving liquid cooling unit can be cooled by the sensible heat of the refrigerant liquid.

In addition, in an absorption refrigerator according to a fifth embodiment of the present invention, for example, as shown in fig. 2, in the absorption refrigerator according to the first embodiment of the present invention, the evaporator 20 is configured by housing the cooling target fluid flow path 21 and the refrigerant V in the evaporator tank 27, and the driving liquid cooling unit 52 is disposed outside the evaporator tank 27 and connected to the evaporator tank 27 via the heat transfer unit 52 w.

With this configuration, the driving liquid cooling unit is additionally provided to the evaporator.

In order to achieve the above object, an absorption refrigerator according to a sixth embodiment of the present invention, as shown in fig. 1 and 2, for example, includes: an evaporator 20 that has an evaporator in which a fluid to be cooled 21 through which a fluid to be cooled C flows and that cools the fluid to be cooled C by taking latent heat of evaporation necessary for evaporating a refrigerant liquid Vf, which is a liquid of a refrigerant V, from the fluid to be cooled C flowing through the fluid to be cooled 21 to become a refrigerant vapor Ve, which is a vapor of the refrigerant V; an absorber 10 that introduces the refrigerant vapor Ve generated in the evaporator 20 and absorbs the absorption liquid Sa; an air extractor 51 for extracting the non-condensable gas Ng in the absorber 10, and configured to introduce and pass the absorbing liquid S in the absorber 10 as a driving liquid Sd to suck the non-condensable gas Ng; and a driving liquid cooling unit 52 that cools the driving liquid Sd introduced into the air extractor 51; the evaporator 20 has an evaporator structure including: the driving liquid cooling unit 52 is provided in contact with the evaporator structure 27(24) so as to transfer heat to and from the evaporator structure 27(24), and includes an evaporator tank 27 for housing the cooling target fluid flow path 21 and the refrigerant V, and a cooling target fluid chamber structural member 24 which is disposed adjacent to the evaporator tank 27 and constitutes a cooling target fluid chamber 24r communicating with the cooling target fluid flow path 21.

With this configuration, the driving liquid cooling unit can be additionally provided to the evaporator.

In addition, in an absorption refrigerator according to a seventh embodiment of the present invention, for example, as shown with reference to fig. 2, in the absorption refrigerator according to the sixth embodiment of the present invention, the driving liquid cooling portion 52 is disposed so as to contact the cooling target fluid chamber structural member 24 along the cooling target fluid chamber structural member 24 outside the cooling target fluid chamber structural member 24.

With this configuration, the drive liquid can be cooled by the cooling target fluid with a simple configuration.

According to the present invention, the fluid in the absorption refrigerator cools the driving liquid, and therefore, a heat exchanger for exchanging heat with the external cooling fluid is not required, and the structure of the device can be simplified.

Drawings

Fig. 1 is a schematic system diagram of an absorption refrigerator according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a part of the structure around the evaporator of an absorption refrigerator according to a modification of the embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or similar reference numerals are given to the same or corresponding components, and redundant description is omitted.

In the present specification, the "absorption chiller" is generally a machine that forms an absorption cycle by a regenerator, a condenser, an absorber, an evaporator, etc. by supplying a heating source to the regenerator, and supplies cold water (a cooling target fluid that is a cooled temperature adjustment target fluid), that is, a narrowly defined absorption chiller, but it also includes a machine that forms an absorption cycle by supplying a heating source to the regenerator, and supplies cold water (a cooling target fluid that is a cooled temperature adjustment target fluid) and/or hot water (a heated temperature adjustment target fluid), that is, an absorption chiller.

First, an absorption refrigerator 1 according to an embodiment of the present invention will be described with reference to fig. 1. FIG. 1 is absorption refrigerationSchematic system diagram of a machine 1. The absorption refrigerator 1 includes, as main constituent devices for performing an absorption refrigeration cycle, an absorber 10, an evaporator 20, a regenerator 30, and a condenser 40, and further includes an ejector 51 as an air-extracting device. The absorption refrigerator 1 is a device that circulates a refrigerant V while changing its phase with respect to an absorption liquid S to perform heat transfer, thereby lowering the temperature of cold water C as a cooling target fluid. In the following description, the absorption liquid is referred to as "dilute solution Sw" or "concentrated solution Sa" depending on the properties and the position on the absorption refrigeration cycle in order to facilitate the distinction in the absorption refrigeration cycle, but is collectively referred to as "absorption liquid S" when the properties and the like are not taken into consideration. The refrigerant is referred to as "evaporator refrigerant vapor Ve", "regenerator refrigerant vapor Vg", "refrigerant liquid Vf" and the like depending on properties and positions on the absorption refrigeration cycle in order to facilitate distinction in the absorption refrigeration cycle, but is collectively referred to as "refrigerant V" when properties and the like are not taken into consideration. In the present embodiment, an aqueous LiBr solution is used as the absorbent S (mixture of the absorbent and the refrigerant), and water (H) is used as the refrigerant V₂O), but is not limited thereto, and other combinations of refrigerants and solutions (absorbents) may be used.

The absorber 10 is a device that absorbs the evaporator refrigerant vapor Ve generated by the evaporator 20 by the rich solution Sa. The absorber 10 includes a cooling pipe 11 serving as a cooling water flow path through which cooling water D flows, and a concentrated solution spray nozzle 12 for spraying the concentrated solution Sa toward the outer surface of the cooling pipe 11, in an absorber tank 17. The concentrated solution spray nozzle 12 is disposed above the cooling pipe 11 so that the sprayed concentrated solution Sa falls on the cooling pipe 11. The absorber 10 is configured such that the sprayed rich solution Sa absorbs the evaporator refrigerant vapor Ve, the diluted solution Sw having a reduced concentration is stored in the storage portion 13 at the lower portion of the absorber tank 17, and the cooling water D deprives the rich solution Sa of absorption heat generated when the evaporator refrigerant vapor Ve is absorbed.

The evaporator 20 is a device that cools the cold water C by evaporating the refrigerant liquid Vf using the heat of the cold water C to generate evaporator refrigerant vapor Ve. The evaporator 20 includes an evaporation tube 21 serving as a cooling fluid flow path through which cold water C flows, and a refrigerant liquid spray nozzle 22 for spraying a refrigerant liquid Vf toward an outer surface of the evaporation tube 21, in an evaporator tank 27. The refrigerant liquid spray nozzle 22 is disposed above the evaporation tube 21 so that the sprayed refrigerant liquid Vf falls on the evaporation tube 21. The evaporator 20 has: a refrigerant liquid pipe 28 for guiding the refrigerant liquid Vf stored in the storage portion 23 at the lower portion of the evaporator tank 27 to the refrigerant liquid spray nozzle 22, and a refrigerant pump 29 for sending the refrigerant liquid Vf in the refrigerant liquid pipe 28 to the refrigerant liquid spray nozzle 22. The evaporator 20 further includes an evaporator refrigerant level meter 25 that detects a high level and a low level of the refrigerant liquid Vf in the reservoir 23. The variation in the level of the refrigerant liquid Vf in the reservoir 23 corresponding to the load of the absorption chiller 1 is designed to be contained between a high level and a low level. The evaporator 20 is configured to cool the cold water C by depriving the cold water C flowing in the evaporation tube 21 of heat of vaporization of the refrigerant liquid Vf sprayed to the outer surface of the evaporation tube 21 to become the evaporation heat of the evaporator refrigerant vapor Ve, and to accumulate the refrigerant liquid Vf that is not evaporated among the sprayed refrigerant liquid Vf in the accumulation portion 23 of the evaporator tank 27.

The evaporator 20 is further provided with a driving liquid cooling unit 52 (hereinafter, simply referred to as "cooling unit 52") that cools the driving liquid Sd introduced into the ejector 51. The cooling section 52 is generally constituted by a pipe through which the driving liquid Sd flows, and is provided inside the evaporator tank 27 in the present embodiment. The cooling portion 52 is generally provided below the evaporation tube 2. The evaporation tubes 21 are generally formed by arranging a plurality of tubes (a plurality of passages) in parallel and/or winding the tubes to form a bundle (tube bundle) of tubes, which constitute the evaporation tubes 21. The cooling portion 52 is provided below the evaporation tubes 21 (tube bundle) configured as described above, and thus the refrigerant liquid Vf sprayed from the refrigerant liquid spray nozzle 22 comes into contact with the outer surfaces of the evaporation tubes 21 and then comes into contact therewith, and/or comes into direct contact with the evaporation tubes 21 through the gaps therebetween. The cooling portion 52 is normally provided between the high liquid level and the low liquid level of the refrigerant liquid Vf in the storage portion 23, and is configured to be submerged by the liquid when the liquid level of the refrigerant liquid Vf in the storage portion 23 becomes the high liquid level and to be exposed (to be in the gas phase portion) when the liquid level becomes the low liquid level due to load fluctuation or the like. In this way, in the present embodiment, the cooling portion 52 is disposed at a position where the refrigerant liquid Vf sprayed from the refrigerant liquid spraying nozzle 22 can contact. Here, the contactable position is a position that is contacted when the cooling portion 52 is not submerged in the refrigerant liquid Vf. The driving liquid Sd passing through the cooling portion 52 is cooled by sensible heat of the refrigerant liquid Vf when submerged in the refrigerant liquid Vf, and is cooled by latent heat when the refrigerant liquid Vf sprayed from the refrigerant liquid spray nozzle 22 and directly or indirectly brought into contact with the cooling portion 52 evaporates when not submerged in the refrigerant liquid Vf. In short, the driving liquid Sd passing through the cooling section 52 is cooled by the refrigerant V in the evaporator 20. The cooling unit 52 is usually installed in the evaporator tank 27 when the evaporation tube 21, the refrigerant liquid spray nozzle 22, and the like are installed in the evaporator tank 27 during the manufacture of the absorption chiller 1.

In the present embodiment, the absorber 10 is disposed adjacent to the evaporator 20, and the upper portion of the absorber tank 17 communicates with the upper portion of the evaporator tank 27. With this configuration, the evaporator refrigerant vapor Ve generated inside the evaporator tank 27 can be guided to the inside of the absorber tank 17. A cooling water inlet pipe 11a into which the cooling water D is introduced is connected to one end of the cooling pipe 11. The cooling water communication tube 14 is connected to the other end of the cooling tube 11. A cooling water supply pipe (not shown) for guiding the cooling water D from a cooling tower (not shown) outside the absorption chiller 1 to the absorber 10 is connected to the cooling water inlet pipe 11 a. A cold water inlet pipe 21a for guiding the cold water C is connected to one end of the evaporation pipe 21, and a cold water outlet pipe 21b for allowing the cold water C to flow out is connected to the other end of the evaporation pipe 21. The chilled water C flowing from the chilled water inlet pipe 21a to the chilled water outlet pipe 21b through the evaporation pipe 21 flows by operation of a chilled water pump (not shown) provided outside the absorption chiller 1.

The regenerator 30 is a device that introduces and heats the dilute solution Sw, and separates the refrigerant V from the dilute solution Sw to generate the concentrated solution Sa. In the regenerator 30, the refrigerant V desorbed from the lean solution Sw is in a vapor state, and this vapor of the refrigerant V is referred to as regenerator refrigerant vapor Vg. The regenerator 30 includes a heating unit 31 for heating the dilute solution Sw, and a regenerator tank 37 for storing the introduced absorbent S. The heating unit 31 is disposed inside the regenerator tank 37. The heating unit 31 is generally configured to be able to heat the absorbent S by heat of steam, hot water, or the like introduced from the outside by combustion heat of a burner. The dilute solution pipe 18 for introducing the dilute solution Sw is connected to the bottom of the regenerator tank 37, and the concentrated solution pipe 38 for allowing the generated concentrated solution Sa to flow out is connected to the upper side surface of the regenerator tank 37. The regenerator 30 is configured such that the dilute solution Sw flowing in from the bottom of the regenerator tank 37 is heated by the heating unit 31, rises, gradually concentrates, and becomes the concentrated solution Sa, and the concentrated solution Sa reaching the liquid level of the concentrated solution pipe 38 flows out from the regenerator tank 37. As the regenerator 30, a cross-flow type regenerator, a flue-pipe type regenerator, a liquid-pipe type regenerator, or the like can be used.

The condenser 40 is a device that introduces and cools the regenerator refrigerant vapor Vg evaporated from the lean solution Sw in the regenerator 30 to condense the vapor, thereby generating the refrigerant liquid Vf to be sent to the evaporator 20. The condenser 40 includes a condenser tube 41, which is a member forming a flow path for the cooling water D, inside the condenser tank 47. The condenser 40 is configured as an accumulating portion 43 that accumulates the generated refrigerant liquid Vf in the lower portion of the condenser tank 47. The other end of the cooling water communication tube 14, one end of which is connected to the cooling tube 11, is connected to one end of the condensation tube 41. A cooling water outlet pipe 41b through which the cooling water D flows out is connected to the other end of the condensation pipe 41. A cooling water return pipe (not shown) for guiding the cooling water D to a cooling tower (not shown) outside the absorption chiller 1 is connected to the cooling water outlet pipe 41 b. According to such a configuration, the cooling water D flowing through the cooling water return pipe (not shown) is cooled by the cooling tower (not shown) and supplied to the cooling water supply pipe (not shown).

The condenser tank 47 is disposed close to the regenerator tank 37. In the present embodiment, the upper portion of the regenerator tank 37 and the upper portion of the condenser tank 47 communicate with each other through the regenerator refrigerant vapor flow path 35. The condenser 40 is configured to introduce the regenerator refrigerant vapor Vg from the regenerator 30 through the regenerator refrigerant vapor flow path 35, deprive the cooling water D flowing through the condensation pipe 41 of heat of the regenerator refrigerant vapor Vg, and condense the regenerator refrigerant vapor Vg into the refrigerant liquid Vf. In the present embodiment, the condenser tank 47 and the regenerator tank 37 are disposed above the evaporator tank 27 and the absorber tank 17. The reservoir 43 of the condenser tank 47 and the evaporator tank 27 are connected by a condensed refrigerant liquid pipe 48, and the refrigerant liquid Vf in the condenser tank 47 can be guided into the evaporator tank 27 by the momentum and the difference between the internal pressures of the two.

The storage section 13 of the absorber tank 17 is connected to the regenerator tank 37 via the dilute solution pipe 18. A solution pump 19 is provided in the dilute solution pipe 18. The absorption refrigerator 1 is configured to be able to transfer the dilute solution Sw in the absorber tank 17 into the regenerator tank 37 by the solution pump 19. As the introduced lean solution Sw moves from the inlet to the outlet in the regenerator tank 37, the refrigerant V is separated from the lean solution Sw and the concentration thereof increases. A drive liquid pipe 53 for guiding a part of the dilute solution Sw flowing toward the regenerator 30 (for example, about 20% of the dilute solution Sw flowing out from the absorber 10) to the ejector 51 as the drive liquid Sd is connected to the dilute solution pipe 18 on the discharge side of the solution pump 19. The drive liquid pipe 53 is configured to sandwich the cooling unit 52 before reaching the ejector 51. In the present embodiment, the drive liquid pipe 53 is configured to include: an upstream driving liquid pipe 53a from the lean solution pipe 18 to the cooling part 52, and a downstream driving liquid pipe 53b on the downstream side of the cooling part 52.

The part of the regenerator tank 37 from which the rich solution Sa flows out is connected to the rich solution spray nozzle 12 of the absorber 10 via a rich solution pipe 38. The absorption chiller 1 is configured to feed the dilute solution Sw to the regenerator tank 37 by the solution pump 19, and to introduce the concentrated solution Sa, which is generated by separating the refrigerant V in the regenerator tank 37, to the concentrated solution spray nozzle 12 through the concentrated solution pipe 38. That is, the solution pump 19 can circulate the absorption liquid S between the absorber 10 and the regenerator 30. A solution heat exchanger 81 is inserted into the dilute solution pipe 18 and the concentrated solution pipe 38, and the solution heat exchanger 81 performs heat exchange between the dilute solution Sw flowing through the dilute solution pipe 18 and the concentrated solution Sa flowing through the concentrated solution pipe 38. The solution heat exchanger 81 is provided in the dilute solution pipe 18 at a position downstream of the branching portion between the dilute solution Sw and the driving liquid pipe 53 as viewed from the flowing direction of the dilute solution Sw.

The ejector 51 is a device for ejecting the noncondensable gas Ng accumulated in the absorber tank 17 to the outside of the machine. The discharger 51 includes a nozzle (not shown) for depressurizing and accelerating the driving liquid Sd, and an inlet 51a for introducing the non-condensable gas Ng as the suction material. An extraction pipe 54 for guiding the non-condensable gas Ng in the absorber tank 17 to the ejector 51 is connected to the inlet 51a of the ejector 51. The nozzle of the ejector 51 is inserted into the downstream drive liquid pipe 53 b. The downstream driving liquid pipe 53b is connected to the suction tank 55 on the downstream side of the ejector 51. The solution pump 19 is a pump for pressure-feeding the dilute solution Sw in the absorber tank 17 to the regenerator 30, and also serves as a drive liquid pump for pressure-feeding the dilute solution Sw in the absorber tank 17 to the ejector 51 and the gas suction tank 55 as the drive liquid Sd.

The gas suction tank 55 is a tank into which the driving liquid Sd and the non-condensable gas Ng of the suction material can be introduced, and stores the collected non-condensable gas Ng. A downstream drive liquid pipe 53b is inserted into the evacuation tank 55. The end of the downstream drive liquid pipe 53b in the evacuation tank 55 opens into the drive liquid Sd stored in the evacuation tank 55. A return driving liquid pipe 56 for returning the driving liquid Sd in the suction tank 55 to the absorber tank 17 is connected to the bottom of the suction tank 55. The return driving liquid pipe 56 is disposed in a U-shape between the evacuation tank 55 and the condensation absorber tank 17 so as to form a liquid collector and to temporarily descend below the bottom of the evacuation tank 55 and the bottom of the absorber tank 17, and is filled with the driving liquid Sd without gas flow when the solution pump 19 is stopped. Thus, the non-condensable gas Ng introduced into the evacuation tank 55 is prevented from flowing back into the absorber 10. A discharge pipe 57 for discharging the separated non-condensable gas Ng to the outside of the system is connected to the ceiling of the evacuation tank 55. A two-way valve 57v is disposed in the discharge pipe 57, and a vacuum pump 57p for discharging the non-condensable gas Ng in the evacuation tank 55 to the outside of the system is disposed downstream of the two-way valve 57 v.

The absorption chiller 1 configured as described above is normally controlled in its operation by the control device 60. The controller 60 is electrically connected to the solution pump 19, the refrigerant pump 29, and the vacuum pump 57p by wires or wirelessly, and can control the start and stop of these pumps. The controller 60 is electrically connected to the evaporator refrigerant level gauge 25 by wire or wirelessly, and can receive the detected liquid level as a signal. The controller 60 is electrically connected to the bidirectional valve 57v by wire or wirelessly, and is configured to be able to adjust the opening degree of the valve.

The operation of the absorption chiller 1 will be described with continued reference to fig. 1. First, the operation of the absorption chiller 1 during steady operation will be described. During the steady operation of the absorption chiller 1, the solution pump 19 and the refrigerant pump 29 are operated by commands from the control device 60. When the circulation of the refrigerant V side is observed, the regenerator refrigerant vapor Vg introduced from the regenerator 30 to the condenser 40 through the regenerator refrigerant vapor flow path 35 is cooled and condensed by the cooling water D flowing through the condensation pipe 41, becomes the refrigerant liquid Vf, and is stored in the storage portion 43 of the condenser tank 47. The cooling water D that cools the regenerator refrigerant vapor Vg rises in temperature, flows out from the cooling water outlet pipe 41b, and is supplied to a cooling tower (not shown). The refrigerant liquid Vf in the condenser tank 47 is introduced into the evaporator tank 27 through the condensed refrigerant liquid pipe 48.

The refrigerant liquid Vf introduced from the condenser tank 47 to the evaporator tank 27 is mixed with the refrigerant liquid Vf sprayed from the refrigerant liquid spray nozzle 22 without being evaporated and is stored in the storage portion 23 of the evaporator tank 27. The refrigerant liquid Vf in the evaporator tank 27 passes through the refrigerant pump 29, flows in the refrigerant liquid pipe 28 and reaches the refrigerant liquid spray nozzle 22. The refrigerant liquid Vf having reached the refrigerant liquid spray nozzle 22 is sprayed toward the evaporation tube 21, obtains heat of the cold water C flowing through the evaporation tube 21, and is partially evaporated to become evaporator refrigerant vapor Ve, which is introduced into the absorber tank 17. The sprayed refrigerant liquid Vf takes up the hot cold water C, lowers the temperature, flows out of the cold water outlet pipe 21b, and is supplied to the use position of the cold water C such as an air conditioner. The refrigerant liquid Vf that is sprayed from the refrigerant liquid spray nozzle 22 and is not evaporated mixes with the refrigerant liquid Vf introduced from the condenser tank 47, and is stored in the storage portion 23 of the evaporator tank 27.

Next, when the circulation of the solution S side of the absorption chiller 1 is observed, the dilute solution Sw stored in the storage unit 13 in the absorber tank 17 flows through the dilute solution pipe 18 by the solution pump 19, is not branched into the drive liquid pipe 53, is increased in temperature by the solution heat exchanger 81, and is then introduced into the regenerator tank 37. The dilute solution Sw introduced into the regenerator tank 37 is heated by the heating unit 31, and the refrigerant V is desorbed to become the concentrated solution Sa. On the other hand, the refrigerant V desorbed from the lean solution Sw is sent as the regenerator refrigerant vapor Vg into the condenser tank 47 through the regenerator refrigerant vapor flow path 35. The rich solution Sa generated in the regenerator tank 37 flows through the rich solution pipe 38, and reaches the rich solution spray nozzle 12 after the temperature thereof is lowered by heat exchange with the lean solution Sw in the solution heat exchanger 81.

The concentrated solution Sa reaching the concentrated solution spray nozzle 12 is sprayed toward the cooling pipe 11, absorbs the evaporator refrigerant vapor Ve introduced from the evaporator 20, and decreases in concentration to become a dilute solution Sw. In the absorber tank 17, absorption heat is generated when the rich solution Sa absorbs the evaporator refrigerant vapor Ve. The generated absorption heat is removed by the cooling water D introduced from the cooling water inlet pipe 11a and flowing through the cooling pipe 11. The cooling water D flowing through the cooling pipe 11 absorbs heat and increases in temperature, flows out to the cooling water communication pipe 14, and is supplied to the condensation pipe 41 of the condenser 40. The dilute solution Sw generated in the absorber tank 17 is stored in the storage portion 13 in the absorber tank 17.

When the absorption liquid S and the refrigerant V perform an absorption refrigeration cycle during operation of the absorption refrigerator 1 as described above, a steel material constituting the absorber tank 17 and the like may react with the absorption liquid S to generate hydrogen gas. In addition, the inside of the absorption refrigerator 1 becomes a negative pressure (less than atmospheric pressure) to promote evaporation of the refrigerant V, and atmospheric air may enter from a pipe connection portion or the like. Such hydrogen gas and atmospheric air that may be present inside the absorption refrigerator 1 are non-condensable gases Ng that are not condensed inside the absorption refrigerator 1. If the non-condensable gas Ng is generated in the absorption refrigerator 1, it tends to concentrate on the absorber 10 having a relatively low pressure in the absorption refrigerator 1. The non-condensable gas Ng adversely affects the absorption of the evaporator refrigerant vapor Ve by the rich solution Sa in the absorber 10 and hinders the heat transfer, so that the capacity of the absorption refrigerator 1 is reduced. In the present embodiment, the noncondensable gas Ng that causes such a failure is sucked by the ejector 51 and discharged from the absorption refrigerator 1 in the following manner.

In the operation of the absorption refrigerator 1, most of the dilute solution Sw flowing through the dilute solution pipe 18 after being discharged from the absorber 10 by the solution pump 19 flows toward the regenerator 30, and a part of the dilute solution Sw is branched to enter the upstream driving liquid pipe 53a as the driving liquid Sd. The driving liquid Sd flowing through the upstream driving liquid pipe 53a enters the cooling unit 52 provided in the evaporator tank 27, and is cooled in the cooling unit 52 by the refrigerant V in the evaporator tank 27. In the present embodiment, since the cooling unit 52 is constituted by the piping provided inside the evaporator tank 27 as described above and exchanges heat with the refrigerant V inside the evaporator tank 27, the driving liquid Sd can be cooled with a simple configuration, compared to a case where heat exchange is performed with an external cooling fluid using, for example, a plate-type heat exchanger, a double-pipe heat exchanger, or the like. The cooled driving liquid Sd flows through the downstream driving liquid pipe 53b and flows into the ejector 51. The driving liquid Sd flowing into the discharger 51 is depressurized and accelerated by a nozzle (not shown) in the discharger 51, and the non-condensable gas Ng is sucked from the absorber 10 through a suction pipe 54 connected to the introduction port 51 a. At this time, the driving liquid Sd flowing into the ejector 51 is cooled by the cooling portion 52, so that the evaporation thereof can be suppressed, and the saturated vapor pressure can be reduced as compared with the dilute solution Sw flowing out from the absorber 10, and the suction performance of the ejector 51 can be improved.

The driving liquid Sd flowing into the ejector 51 is mixed with the non-condensable gas Ng, flows out of the ejector 51, flows through the downstream driving liquid pipe 53b, and flows into the evacuation tank 55. The mixed fluid of the driving liquid Sd and the non-condensable gas Ng flowing into the gas evacuation tank 55 is separated, and the driving liquid Sd is accumulated in the lower portion of the gas evacuation tank 55 and the non-condensable gas Ng is accumulated in the upper portion of the gas evacuation tank 55. The driving liquid Sd in the suction tank 55 is returned to the absorber 10 through the return driving liquid pipe 56. The extraction of the non-condensable gas Ng from the absorber 10 to the extraction tank 55 is performed at all times during the operation of the absorption refrigerator 1. The evacuation tank 55 can accumulate the non-condensable gas Ng even if the evacuation from the discharge pipe 57 is not always performed. The non-condensable gas Ng in the evacuation tank 55 is discharged to the outside of the system through the discharge pipe 57 by opening the two-way valve 57v which is activated by the vacuum pump 57p and is always closed. In this way, the non-condensable gas Ng in the absorber 10 is discharged from the absorption refrigerator 1. The timing of discharging the non-condensable gas Ng from the evacuation tank 55 may be performed, for example, each time the absorption refrigerator 1 is started and/or stopped, or may be performed by controlling the opening and closing of the two-way valve 57v by a timer (not shown) for a predetermined time.

As described above, according to the absorption refrigerator 1 of the present embodiment, the cooling portion 52 provided inside the evaporator tank 27 cools the driving liquid Sd flowing into the ejector 51 by the refrigerant V, so that a heat exchanger for exchanging heat with an external cooling fluid is not required, and the structure can be simplified. Further, the cooling section 52 is provided below the bundle of the evaporation tubes 21 in the evaporator tank 27 and between the high liquid level and the low liquid level in the storage section 23, therefore, under the condition that the concentration of the absorption liquid S in the absorption refrigeration cycle is low (the refrigeration load is low, the temperature of the cooling water D is low, etc.), the refrigerant liquid Vf sprayed from the refrigerant liquid spray nozzle 22 contacts the exposed cooling portion 52 with the liquid level of the refrigerant liquid Vf in the storage portion 23 lowered, and the driving liquid Sd in the cooling portion 52 can be cooled by the latent heat of evaporation of the refrigerant liquid Vf in contact, under the condition that the concentration of the absorption liquid S in the absorption refrigeration cycle is high (the refrigeration load is high, the temperature of the cooling water D is high, scale adheres to the cooling water D, and the like), the driving liquid Sd in the cooling unit 52 submerged by the increase in the liquid level of the refrigerant liquid Vf in the storage unit 23 can be cooled by the sensible heat of the surrounding refrigerant liquid Vf. Further, since the temperature difference between the refrigerant liquid Vf and the dilute solution Sw becomes large at the time of high load, the driving liquid Sd can be sufficiently cooled even by the sensible heat of the refrigerant liquid Vf.

Next, an absorption refrigerator 2 according to a modification of the embodiment of the present invention will be described with reference to fig. 2. Fig. 2 is a partial schematic diagram of the periphery of the evaporator 20 constituting the absorption refrigerator 2. Hereinafter, the portions different from the absorption refrigerator 1 (see fig. 1) will be mainly described, and the description of the same portions will be omitted. In fig. 2, the absorber 10, the regenerator 30, the condenser 40, and the attached parts, which are not shown, are configured in the same manner as the absorption refrigerator 1 shown in fig. 1. The absorption chiller 2 is different from the absorption chiller 1 (see fig. 1) in that the cooling unit 52 is not provided inside the evaporator tank 27 but outside the evaporator tank 27. In fig. 2, the structure around the evaporator 20 is shown in more detail. The evaporator tank 27 has a pair of tube sheets 26. The pair of tube plates 26 are arranged in parallel with a space therebetween. The tube plate 26 is disposed so that the normal line thereof is horizontal. The evaporation tube 21 in the form of a tube is disposed between the pair of tube plates 26. The evaporation tubes 21 have one end connected to one tube sheet 26 and the other end connected to the other tube sheet 26. The tube plate 26 has a hole through which the tube of the evaporation tube 21 can be inserted at a position where the tube of the evaporation tube 21 is connected. The tube ends of the evaporation tubes 21 are inserted through holes formed in the tube sheet 26, and the tube ends are expanded outside the tube sheet 26, so that the tube ends of the evaporation tubes 21 are fixed to the tube sheet 26. The interior of the tubes of the evaporator tube 21, both ends of which are joined to the tube sheet 26, do not communicate with the interior of the evaporator tank 27. In other words, the cold water C flowing through the tubes of the evaporation tubes 21 is not mixed with the refrigerant V in the evaporator tank 27.

A water chamber forming member 24 is provided on the outer side of each of the pair of tube plates 26. Header forming member 24 is a member in which header 24r, which is a cooling target fluid chamber for supplying cold water C to the tubes of evaporation tube 21 or collecting cold water C from the tubes of evaporation tube 21, is formed, and corresponds to a cooling target fluid chamber component. The header forming member 24 is a rectangular parallelepiped member having an opening on one surface, and is attached to the outer side of each of the pair of tube plates 26 so that the opening covers the end portions of all the tubes of the evaporation tubes 21 attached to the respective tube plates 26. The water chamber forming member 24 is attached to the tube plate 26, and thus a space surrounded by the water chamber forming member 24 and the tube plate 26 becomes the water chamber 24 r. The evaporator 20 having the pair of tube sheets 26 and the water chamber forming part 24 forms two water chambers 24 in the case of one channel. Each of the water chambers 24r communicates with the inside of the tube of the evaporation tube 21. That is, the cold water C flows into or out of the water chamber 24 r. One end of the tube of evaporation tube 21 opens into one header 24r that supplies cold water C to the tube of evaporation tube 21, and the other end of the tube of evaporation tube 21 opens into the other header 24r that collects cold water C from the tube of evaporation tube 21. The evaporator structure is composed of an evaporator tank 27, a tube sheet 26, and a water chamber forming member 24.

In the present modification, the cooling portion 52 is attached to the lower portion of the evaporator tank 27 outside the evaporator tank 27 by welding, with respect to the structure around the evaporator tank 27. The cooling portion 52 may be welded to the evaporator tank 27 at a plurality of positions, or the entire cooling portion 52 may be brought into close contact with the evaporator tank 27. The evaporator tank 27 and the cooling portion 52, which are attached by welding, perform heat transfer via the welded portion 52w, and therefore the welded portion 52w corresponds to a heat transfer portion. As in the present modification, if the cooling unit 52 is attached to the outside of the evaporator tank 27, the cooling unit 52 can be additionally installed in the conventional absorption refrigerator, and the efficiency of the ejector 51 can be improved by installing the cooling unit 52 by a modification. In the absorption refrigerator 2 in which the cooling unit 52 is disposed in this manner, when the driving liquid Sd flowing through the driving liquid pipe 53 passes through the cooling unit 52, the cold heat of the refrigerant V in the evaporator 20 is transferred to the cooling unit 52 via the welded portion 52w, is cooled, and then flows into the ejector 51. Therefore, as in the absorption refrigerator 1 (see fig. 1), the absorption refrigerator 2 can suppress its own evaporation, and can lower the saturated vapor pressure as compared with the dilute solution Sw flowing out from the absorber 10, thereby improving the suction performance of the ejector 51.

Instead of connecting cooling unit 52 to the lower side of evaporator tank 27, cooling unit 52 may be connected to water chamber forming member 24 by welding, as shown by the phantom line (two-dot chain line) in fig. 2. With such an arrangement, the degree of freedom in the arrangement of the cooling unit 52 can be improved. Alternatively, as another configuration, although not shown, the cooling unit 52 may be connected to the pipe for the cold water C and the pipe for the cooling water D via the heat transfer unit.

In the above description, when the cooling portion 52 is provided inside the evaporator tank 27, it is disposed below the bundle of the evaporation tubes 21, but it may be disposed above or on the side of the bundle of the evaporation tubes 21. However, from the viewpoint of preferentially absorbing the effect of the refrigeration cycle, it is preferable to dispose it below the bundle of evaporation tubes 21.

In the above description, for the sake of easy understanding, the absorption chiller 1 has a single-effect structure, but may be applied to a multi-effect absorption chiller having a plurality of regenerators or an absorption chiller having a plurality of evaporators/absorbers having different operating pressures.

Description of the reference numerals

1 … absorption refrigerator; 10 … absorber; 19 … solution pump; 20 … evaporator; 21 … evaporation tube; 22 … refrigerant liquid spray nozzles; 24 … water chamber forming part; 24r … water chamber; 26 … a tube sheet; 27 … evaporator tank; 30 … regenerator; a 40 … condenser; a 51 … ejector; 52 … cooling part; 52w … welded portion; c … Cold Water; ng … non-condensable gas; s … absorbing liquid; concentrated solution Sa …; sd … draw solution; v … refrigerant; vf … refrigerant liquid; ve … evaporator refrigerant vapor.

Claims

1. An absorption refrigerator, comprising:

an evaporator that has a cooling target fluid flow path in which a cooling target fluid flows, and cools the cooling target fluid by taking latent heat of evaporation necessary for evaporating a refrigerant liquid, which is a liquid of a refrigerant, from the cooling target fluid flowing through the cooling target fluid flow path to turn the refrigerant liquid into a refrigerant vapor, which is a vapor of the refrigerant;

an absorber that introduces the refrigerant vapor generated in the evaporator and absorbs an absorption liquid;

an air extractor configured to extract the non-condensable gas in the absorber, the air extractor being configured to introduce and pass the absorption liquid in the absorber as a driving liquid to suck the non-condensable gas; and

and a driving liquid cooling unit that cools the driving liquid introduced into the air-extracting device by the refrigerant of the evaporator.

2. An absorption chiller according to claim 1,

the driving liquid cooling unit is disposed inside the evaporator.

3. An absorption chiller according to claim 2,

the evaporator has a refrigerant liquid spraying device that sprays the refrigerant liquid toward the cooling target fluid flow path,

the driving liquid cooling portion is disposed at a position where the refrigerant liquid sprayed from the refrigerant liquid spraying device can contact.

4. An absorption chiller according to claim 2 or 3,

the driving liquid cooling portion is disposed between a lowest liquid level and a highest liquid level of the refrigerant liquid in the evaporator.

5. An absorption chiller according to claim 1,

the evaporator is configured by accommodating the cooling target fluid flow path and the refrigerant in an evaporator tank;

the driving liquid cooling unit is disposed outside the evaporator tank and connected to the evaporator tank via a heat transfer unit.

6. An absorption refrigerator, comprising:

a driving liquid cooling unit that cools the driving liquid introduced into the air-extracting device;

the evaporator has an evaporator structure including: an evaporator tank for housing the cooling target fluid flow path and the refrigerant, and a cooling target fluid chamber structural member disposed adjacent to the evaporator tank and constituting a cooling target fluid chamber communicating with the cooling target fluid flow path,

the driving liquid cooling unit is provided in contact with the evaporator structure so as to transfer heat to the evaporator structure.

7. An absorption chiller according to claim 6,

the driving liquid cooling unit is disposed outside the cooling target fluid chamber component so as to be in contact with the cooling target fluid chamber component along the cooling target fluid chamber component.