CN108072205B

CN108072205B - Absorber and absorption heat pump

Info

Publication number: CN108072205B
Application number: CN201711055889.3A
Authority: CN
Inventors: 竹村与四郎
Original assignee: Ebara Refrigeration Equipment and Systems Co Ltd
Current assignee: Ebara Refrigeration Equipment and Systems Co Ltd
Priority date: 2016-11-08
Filing date: 2017-11-01
Publication date: 2022-03-22
Anticipated expiration: 2037-11-01
Also published as: CN108072205A

Abstract

The invention provides an absorber and an absorption heat pump. The absorber (10) is provided with a plurality of heat transfer tubes (12) through which a medium (W) to be heated, at least a part of which is liquid, flows, and is further provided with a reversing section (14r) which guides the medium (W) to be heated, which flows inside the heat transfer tubes (12A), to other heat transfer tubes (12B) so as to flow inside the other heat transfer tubes (12B) in opposite directions, wherein the plurality of heat transfer tubes are configured into a plurality of paths (P1, Pf) through the reversing section, the plurality of paths are configured so that the cross-sectional areas of the paths are the same, and the medium to be heated, which flows inside the heat transfer tubes, is heated by absorption heat generated when an absorption liquid (Sa) outside the heat transfer tubes absorbs vapor (Ve) of a refrigerant, and the liquid (Wq) of the medium to be heated is boiled. The absorption heat pump is provided with: an absorber; and a regenerator for introducing and heating the absorption liquid (Sw) having a decreased concentration by absorbing the vapor of the refrigerant in the absorber, and for separating the refrigerant to increase the concentration of the absorption liquid.

Description

Absorber and absorption heat pump

Technical Field

The present invention relates to an absorber and an absorption heat pump, and more particularly, to an absorber and an absorption heat pump that prevent a heat transfer pipe through which liquid does not flow and suppress a decrease in evaporation performance of a medium to be heated.

Background

Absorption heat pumps are known, which are: the refrigerant vapor generated in the evaporator is guided to the absorber, and the liquid of the medium to be heated is heated by the absorption heat generated when the refrigerant vapor is absorbed in the absorption solution in the absorber, thereby generating vapor of the medium to be heated. In order to prevent the flow of the medium to be heated from becoming unstable due to the increase in volume being hindered when the liquid of the medium to be heated becomes vapor, the absorber is configured as follows. In this absorber, a plurality of pipes through which a medium to be heated flows are horizontally arranged. And water chambers are respectively arranged at two ends of the plurality of pipes. The water chamber is divided into a plurality of parts by a plurality of division plates. A plurality of tubes are connected to each of the water chambers partitioned by the partition plate. The partition plate is provided to divide the water chamber so that the entire heating medium, which flows as a single fluid, flows from below to above, with the tubes and the water chamber as a whole. In addition, the partition plate is provided with: the total area of the flow channel cross-sectional areas of the set of tubes through which the heating medium flows out of a certain header is larger than the total area of the flow channel cross-sectional areas of the set of tubes through which the heating medium flows into the header (see, for example, patent document 1).

Patent document 1: japanese patent laid-open No. 2010-164248 (paragraphs 0034 to 0037, etc.)

The heated medium flowing in the pipe is heated by absorbing heat, and thus a part of the liquid is evaporated and flows along with the gas. In this case, for example, when the medium to be heated is water, the volume of the evaporated gas is several hundred times larger than the volume of the liquid, and therefore, in some of the water chambers, when the medium to be heated flows out from the lower tube group and flows into the next upper tube group, there is a case where a tube into which the liquid does not flow due to the flowing state appears. In the pipe into which the liquid does not flow, the absorption heat is not efficiently transferred to the heated medium.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an absorber and an absorption heat pump that prevent the occurrence of a heat transfer pipe into which the liquid of the medium to be heated does not flow, and that suppress the deterioration of the evaporation performance of the medium to be heated.

In order to achieve the above object, an absorber according to a first aspect of the present invention is provided in an absorption heat pump 1 (see fig. 1), as shown in, for example, fig. 1 and 2, the absorption heat pump 1 draws heat of the introduced heat source fluid h by an absorption heat pump cycle of the absorbent S and the refrigerant V, wherein the absorber 10 includes a plurality of heat transfer tubes 12 through which a medium to be heated W at least a part of which is liquid flows, the absorber 10 further includes a reversing section 14r, the inversion section 14r guides the medium W to be heated flowing inside the heat transfer pipe 12A to the other heat transfer pipe 12B so as to flow in the opposite direction inside the other heat transfer pipe 12B, the plurality of heat transfer pipes 12 are configured as a plurality of paths P1, Pf via the inversion section 14r, the plurality of paths P1, Pf are configured such that the flow path cross-sectional areas are the same, and the absorber 10 is configured such that: the medium W to be heated flowing inside the heat transfer tubes 12 is heated by the absorption heat generated when the vapor Ve of the refrigerant is absorbed by the outer absorption liquid Sa of the heat transfer tubes 12, and the liquid Wq of the medium to be heated is boiled.

With this configuration, when the ratio of the vapor of the medium to be heated increases with the flow to the downstream side of the flow, the flow path cross-sectional areas of the respective paths are configured to be approximately the same, and therefore, as the flow rate of the medium to be heated increases with the flow to the downstream side of the flow, the liquid of the medium to be heated flows into the respective heat transfer tubes along with the flow of the vapor of the medium to be heated, and therefore, the occurrence of heat transfer tubes into which the liquid does not flow can be avoided, and the deterioration of the evaporation performance of the liquid of the medium to be heated can be suppressed.

In the absorber according to the second aspect of the present invention, as shown in fig. 2, for example, in the absorber 10 according to the first aspect of the present invention, the plurality of paths P1 and Pf are configured so that the flow path cross-sectional areas are uniform.

With this configuration, the following balance can be achieved: the balance between the increase in flow resistance associated with an increase in the flow velocity of the heating medium with the downstream-side path and the reduction in evaporation performance is suppressed.

In the absorber according to the third aspect of the present invention, as shown in fig. 2, for example, in the absorber 10 according to the first aspect of the present invention, the paths P1 and Pf are respectively configured as follows: the ratio of the flow path cross-sectional areas is within a predetermined range in which the heat transfer tubes 12 are prevented from flowing in the liquid Wq of the medium to be heated.

With this configuration, the heat transfer tube into which liquid does not flow can be prevented from occurring.

In the absorber according to the fourth aspect of the present invention, as shown in fig. 2, for example, in the absorber 10 according to the first aspect of the present invention, the paths P1 and Pf are respectively configured as follows: the ratio of the flow path cross-sectional areas is within a predetermined range in which the occurrence of the heat transfer pipe 12 into which the small flow rate of the liquid Wq of the heating medium W can be prevented to such an extent that the decrease in the amount of vapor generation of the heating medium W substantially exceeds the allowable range.

With this configuration, not only the occurrence of the heat transfer pipe into which no liquid flows but also the occurrence of the heat transfer pipe into which the flow rate of the liquid of the heating target medium is too small can be avoided, and the deterioration of the evaporation performance can be further suppressed.

An absorber according to a fifth aspect of the present invention is, for example, as shown in fig. 2, the absorber 10 according to any one of the first to fourth aspects of the present invention, wherein the absorber includes a gas-liquid separator 80 that separates the gas Wv from the liquid Wq of the medium W to be heated, the plurality of paths include a first path P1 and a final path Pf, the first path P1 is a path into which the medium W to be heated first flows, the final path Pf is a path into which the medium W to be heated last flows, and the gas-liquid separator 80 is configured to: the pressure of the liquid heating medium Wq fed from the gas-liquid separator 80 to the first path P1 while the gas-liquid mixed heating medium Wm is introduced from the final path Pf and the separated liquid heating medium Wq is fed to the first path P1 is configured as follows: the difference in height between the heat transfer pipe 12 and the gas-liquid separator 80 provided above the heat transfer pipe 12 is given, or the pump for pressurizing the liquid medium Wq to be heated is given, and the number of the paths is: the flow rate of the medium to be heated Wq flowing into the first path P1 can be ensured at a predetermined flow rate by the pressing pressure of the medium to be heated Wq supplied to the first path P1.

With this configuration, the medium to be heated supplied to each heat transfer pipe can be efficiently evaporated.

In the absorber 10 according to the sixth aspect of the present invention, as shown in fig. 2, for example, the horizontal cross-sectional area of the inverting portion 14r is configured such that: the outlet liquid chamber 14f is connected to the outlet side of the path Pf, into which the heated medium W finally flows, among the plurality of paths, and is smaller than the horizontal sectional area of the outlet liquid chamber 14 f.

With this configuration, the occurrence of the heat transfer pipe in which the amount of vapor generated is reduced due to no inflow of the liquid of the medium to be heated can be suppressed.

In the absorber according to the seventh aspect of the present invention, as shown in fig. 3, for example, in the absorber 10A according to the sixth aspect of the present invention, the inverting section 14r is formed in plural, and the horizontal cross-sectional area of each of the plural inverting sections 14r is configured as follows: the horizontal cross-sectional area of the inlet liquid chamber 14e connected to the inlet side of the path P1 into which the medium W to be heated first flows out of the plurality of paths is configured to be gradually reduced from the downstream side toward the upstream side in the flow direction of the medium W to be heated: is smaller than the horizontal cross-sectional area of the most upstream inversion section 14r or is about the same as the horizontal cross-sectional area of the most upstream inversion section 14 r.

With this configuration, the liquid and the vapor in the medium to be heated passing through each inversion portion can approach the flow velocity at which they flow integrally, and variation in the flow rate of the liquid of the medium to be heated flowing into each heat transfer pipe can be suppressed.

In the absorber according to the eighth aspect of the present invention, as shown in fig. 2, for example, in the absorber 10 according to any one of the first to sixth aspects of the present invention, the inverting portion 14r is formed of one.

With this configuration, the two paths are formed, and the medium to be heated is likely to boil in the heat transfer pipe constituting the first path, thereby improving the bubble pump effect.

An absorber according to a ninth aspect of the present invention is, for example, as shown in fig. 2, the absorber 10 according to any one of the first to eighth aspects of the present invention, wherein: a part of the liquid Wq of the heating medium boils inside the heat transfer pipe 12A constituting the path P1 into which the heating medium W first flows out of the plurality of paths.

With this configuration, the effect of the bubble pump can be improved.

An absorption heat pump according to a tenth aspect of the present invention, as shown in fig. 1, for example, includes: the absorber 10 according to any one of the first to ninth aspects of the present invention described above; and a regenerator 30 for introducing and heating the absorption liquid Sw whose concentration has decreased by absorbing the vapor Ve of the refrigerant in the absorber 10, and for separating the refrigerant Vg to increase the concentration of the absorption liquid Sw.

With this configuration, the absorption heat pump is suppressed in the decrease in the efficiency of extracting the vapor of the heating medium.

According to the present invention, since the flow path cross-sectional areas of the respective paths are configured to be approximately the same when the ratio of the vapor of the medium to be heated increases with the downstream side of the forward flow, the liquid of the medium to be heated flows into the respective heat transfer tubes with the flow of the vapor of the medium to be heated as the flow speed of the medium to be heated increases with the downstream side of the forward flow, and thus the occurrence of heat transfer tubes into which the liquid does not flow can be avoided, and the deterioration of the evaporation performance of the liquid of the medium to be heated can be suppressed.

Drawings

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

Fig. 2 is a sectional view around an absorber of an embodiment of the present invention.

Fig. 3 is a cross-sectional view of the periphery of an absorber according to a first modification of the embodiment of the present invention.

Fig. 4 is a sectional view of the periphery of an absorber according to a second modification of the embodiment of the present invention.

Fig. 5 is a schematic system diagram of a two-stage heating absorption heat pump according to a modification of the embodiment of the present invention.

Description of reference numerals: 1.1 a … absorption heat pump; 10. 10A, 10B … absorber; 12 … heat transfer tubes; 14e … inlet liquid chamber; 14f … outlet liquid chamber; 14r … reversal liquid chamber; 30 … regenerator; 80 … gas-liquid separator; h … hot water of heat source; a P1 … first path; pf … final path; s … absorbing liquid; sw … diluted solution; v … refrigerant; ve … evaporator refrigerant vapor; vg … regenerator refrigerant vapor; w … heated medium; wq … is heated with the medium liquid; wv … is heated with the medium vapor.

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.

First, an absorption heat pump 1 according to an embodiment of the present invention will be described with reference to fig. 1. Fig. 1 is a schematic system diagram of an absorption heat pump 1. First, the overall structure and operation of the absorption heat pump 1 will be described, and then the absorber 10, which is one of the components of the absorption heat pump 1, will be described in detail. The absorption heat pump 1 includes: the absorption heat pump cycle includes an absorber 10, an evaporator 20, a regenerator 30, and a condenser 40, which constitute main devices for performing an absorption heat pump cycle of an absorption liquid S (Sa, Sw) and a refrigerant V (Ve, Vg, Vf).

In the present specification, the absorption liquid is referred to as "dilute solution Sw" or "concentrated solution Sa" depending on the properties and the position on the heat pump cycle in order to facilitate the distinction of the heat pump cycle, but is collectively referred to as "absorption liquid S" or "solution S" when the properties and the like are not concerned. Similarly, the refrigerant is referred to as "evaporator refrigerant vapor Ve", "regenerator refrigerant vapor Vg", "refrigerant liquid Vf", and the like, depending on the properties and the position on the heat pump cycle, in order to facilitate the distinction in the heat pump cycle, but is collectively referred to as "refrigerant V" when the properties and the like are not different. In the present embodiment, an aqueous LiBr solution is used as the absorbent S (mixture of the absorbent and the refrigerant V), and water (H) is used₂O) as refrigerant V. The medium W is a general term for a liquid Wq of the medium W to be heated as a liquid to be supplied to the absorber 10, a vapor Wv of the medium to be heated as a gas, a mixed medium Wm of the medium to be heated in a state where the liquid and the gas are mixed, and a makeup water Ws of a makeup liquid as a makeup liquid of the medium to be heated to be replenished from outside the absorption heat pump 1. In the present embodiment, water (H) is used₂O) as the heating medium W.

The absorber 10 has therein: a heat transfer pipe 12 constituting a flow path of the medium W to be heated, and a concentrated solution spreading nozzle 13 for spreading the concentrated solution Sa. The absorber 10 generates absorption heat when the rich solution Sa is dispersed from the rich solution dispersing nozzle 13, and the rich solution Sa absorbs the evaporator refrigerant vapor Ve. The medium W to be heated flowing through the heat transfer pipe 12 is heated by the absorption heat, and the medium W to be heated is thereby heated.

The absorber 10 has a gas-liquid separator 80 in addition to the above structure. The gas-liquid separator 80 is a device that introduces the heating medium W heated by flowing through the heat transfer pipe 12 and separates the heating medium vapor Wv from the heating medium liquid Wq. The gas-liquid separator 80 is connected to the heat transfer pipe 12 via a heating medium liquid pipe 82 and an outflow pipe 84, the heating medium liquid pipe 82 guiding the heating medium liquid Wq in the gas-liquid separator 80 to the heat transfer pipe 12, and the outflow pipe 84 guiding the heating medium W flowing through the heat transfer pipe 12 and heated to the gas-liquid separator 80. A heating target medium steam pipe 89 is connected to the gas-liquid separator 80, and the heating target medium steam pipe 89 guides the separated heating target medium steam Wv to the outside of the absorption heat pump 1. Further, a makeup water pipe 85 is provided, and the makeup water pipe 85 introduces makeup water Ws for replenishing the heating medium W in a portion supplied to the outside of the absorption heat pump 1 mainly as steam from the outside of the absorption heat pump 1. The makeup water pipe 85 is constituted by: is connected to the heating medium liquid pipe 82, and joins the makeup water Ws and the heating medium liquid Wq flowing through the heating medium liquid pipe 82. A makeup water pump 86 is disposed in the makeup water pipe 85, and the makeup water pump 86 pressure-feeds the makeup water Ws toward the heating medium liquid pipe 82.

The evaporator 20 includes a heat source tube 21 and a refrigerant liquid distribution nozzle 22 therein, the heat source tube 21 forming a flow path of heat source hot water h as a heat source fluid, and the refrigerant liquid distribution nozzle 22 distributing a refrigerant liquid Vf toward the heat source tube 21. The evaporator 20 is constituted by: the refrigerant liquid Vf is distributed from the refrigerant liquid distribution nozzle 22, and the distributed refrigerant liquid Vf is evaporated by the heat of the heat source hot water h flowing in the heat source tube 21, thereby generating evaporator refrigerant vapor Ve. The absorber 10 and the evaporator 20 are formed in a cylinder in such a manner as to communicate with each other. The absorber 10 is configured to communicate with the evaporator 20, and thereby the evaporator refrigerant vapor Ve generated in the evaporator 20 can be supplied to the absorber 10.

The regenerator 30 has: a heat source pipe 31 inside which a heat source hot water h as a heat source fluid for heating the dilute solution Sw flows; and a dilute solution dispersing nozzle 32 which disperses the dilute solution Sw. The heat source hot water h flowing through the heat source pipe 31 may be the same fluid as the heat source hot water h flowing through the heat source pipe 21 or may be a different fluid. The regenerator 30 is configured to: the dilute solution Sw sprayed from the dilute solution spraying nozzle 32 is heated by the heat source hot water h, whereby the refrigerant V evaporates from the dilute solution Sw to generate the concentrated solution Sa whose concentration rises. The refrigerant V evaporated from the weak solution Sw is constituted: moves as regenerator refrigerant vapor Vg toward the condenser 40.

The condenser 40 has a cooling water pipe 41, and cooling water c as a cooling medium flows through the cooling water pipe 41. The condenser 40 is constituted: the regenerator refrigerant vapor Vg generated by the regenerator 30 is introduced, and is cooled and condensed by the cooling water c. The regenerator 30 and the condenser 40 are formed in one cylinder in such a manner as to communicate with each other. The structure is as follows: the regenerator 30 is in communication with the condenser 40, and thereby the regenerator refrigerant vapor Vg generated by the regenerator 30 can be supplied to the condenser 40. Further, the structure is as follows: the absorber 10 and the evaporator 20 are disposed at a higher position than the regenerator 30 and the condenser 40, and the absorption liquid S in the absorber 10 can be sent to the regenerator 30 and the refrigerant liquid Vf in the evaporator 20 can be sent to the condenser 40 by momentum.

The portion of the regenerator 30 that stores the rich solution Sa is connected to the rich solution distribution nozzle 13 of the absorber 10 through a rich solution pipe 35 through which the rich solution Sa flows. A solution pump 35p for pressure-feeding the concentrated solution Sa is provided in the concentrated solution pipe 35. The portion of the absorber 10 that stores the dilute solution Sw is connected to the dilute solution distribution nozzle 32 through a dilute solution pipe 36 through which the dilute solution Sw flows. A solution heat exchanger 38 that exchanges heat between the rich solution Sa and the lean solution Sw is disposed in the rich solution pipe 35 and the lean solution pipe 36. The portion of the condenser 40 storing the refrigerant liquid Vf is connected to the refrigerant liquid distribution nozzle 22 of the evaporator 20 via a refrigerant liquid pipe 45 through which the refrigerant liquid Vf flows. A refrigerant pump 46 for pressurizing and feeding the refrigerant liquid Vf is disposed in the refrigerant liquid pipe 45. The portion of the evaporator 20 where the refrigerant liquid Vf is stored without being evaporated is connected to the condenser 40 by a refrigerant liquid pipe 25, and the refrigerant liquid pipe 25 returns the refrigerant liquid Vf that has been distributed from the refrigerant liquid distribution nozzle 22 without being evaporated to the condenser 40. A refrigerant heat exchanger 48 is disposed in the refrigerant liquid pipe 25 and the refrigerant liquid pipe 45, and the refrigerant heat exchanger 48 performs heat exchange between the refrigerant liquids Vf flowing through the

pipes

25 and 45, respectively.

The operation of the absorption heat pump 1 will be described with continued reference to fig. 1. First, the refrigerant-side cycle is explained. The condenser 40 receives the regenerator refrigerant vapor Vg evaporated in the regenerator 30, and is cooled and condensed by the cooling water c flowing through the cooling water pipe 41 to become a refrigerant liquid Vf. The condensed refrigerant liquid Vf is sent to the refrigerant liquid distribution nozzle 22 of the evaporator 20 by the refrigerant pump 46. The refrigerant liquid Vf sent to the refrigerant liquid distribution nozzle 22 is distributed toward the heat source tube 21, and is heated and evaporated by the heat source hot water h flowing through the heat source tube 21 to become the evaporator refrigerant vapor Ve. The evaporator refrigerant vapor Ve generated in the evaporator 20 moves toward the absorber 10 communicating with the evaporator 20. The refrigerant liquid Vf that has been distributed from the refrigerant liquid distribution nozzle 22 without being evaporated returns to the condenser 40 through the refrigerant liquid pipe 25.

Next, circulation on the solution side will be described. In the absorber 10, the rich solution Sa is dispersed from the rich solution dispersing nozzle 13, and the dispersed rich solution Sa absorbs the evaporator refrigerant vapor Ve moving from the evaporator 20. The concentrated solution Sa having absorbed the evaporator refrigerant vapor Ve becomes a dilute solution Sw as a result of a decrease in concentration. In the absorber 10, absorption heat is generated when the rich solution Sa absorbs the evaporator refrigerant vapor Ve. The medium W to be heated flowing through the heat transfer pipe 12 is heated by the absorption heat. The rich solution Sa having absorbed the evaporator refrigerant vapor Ve in the absorber 10 is reduced in concentration to become a lean solution Sw and is stored in the lower portion of the absorber 10. The stored dilute solution Sw flows in the dilute solution pipe 36 toward the regenerator 30 due to gravity and a difference between the internal pressures of the absorber 10 and the regenerator 30, and exchanges heat with the concentrated solution Sa by the solution heat exchanger 38, and the temperature thereof is lowered to reach the regenerator 30.

The dilute solution Sw sent to the regenerator 30 is sprayed from the dilute solution spraying nozzle 32, and is heated by the heat source hot water h (about 80 ℃ in the present embodiment) flowing through the heat source pipe 31, so that the refrigerant in the sprayed dilute solution Sw evaporates to become the concentrated solution Sa, which is stored in the lower portion of the regenerator 30. On the other hand, the refrigerant V evaporated from the lean solution Sw moves to the condenser 40 as the regenerator refrigerant vapor Vg. The rich solution Sa stored in the lower part of the regenerator 30 is pressurized and fed by the solution pump 35p to the rich solution distribution nozzle 13 of the absorber 10 via the rich solution pipe 35. The rich solution Sa flowing through the rich solution pipe 35 exchanges heat with the lean solution Sw in the solution heat exchanger 38, and flows into the absorber 10 after the temperature rises, and is dispersed from the rich solution dispersion nozzle 13. The concentrated solution Sa returned to the absorber 10 absorbs the evaporator refrigerant vapor Ve, and thereafter, the same cycle is repeated.

In the absorber 10, while the absorption liquid S and the refrigerant V are in the absorption heat pump cycle as described above, the heating medium liquid Wq is heated by the absorption heat generated when the evaporator refrigerant vapor Ve is absorbed by the rich solution Sa, and a part of the heating medium liquid Wq is boiled into wet vapor (mixed with the heating medium Wm) and guided to the gas-liquid separator 80. The mixed heating medium Wm that flows into the gas-liquid separator 80 is separated into the heating medium vapor Wv and the heating medium liquid Wq. The heating medium vapor Wv separated by the gas-liquid separator 80 flows out to the heating medium vapor pipe 89, and is supplied to a vapor utilization place (demand destination) outside the absorption heat pump 1. That is, the heating medium vapor Wv is taken out of the absorption heat pump 1. In this way, the absorption heat pump 1 is configured as a second absorption heat pump capable of extracting the medium W to be heated, which is at a temperature equal to or higher than the temperature of the driving heat source. On the other hand, the heating medium liquid Wq separated by the gas-liquid separator 80 flows through the heating medium liquid pipe 82 and is supplied into the heat transfer pipe 12. At this time, when the makeup water Ws flows from the makeup water pipe 85, the makeup water Ws merges with the heating medium liquid Wq flowing through the heating medium liquid pipe 82, and is supplied into the heat transfer pipe 12 as the heating medium liquid Wq. Typically, the medium to be heated W is supplied to the outside as the amount of the medium to be heated vapor Wv, and is supplied from the outside of the absorption heat pump 1 as the makeup water Ws. Each device constituting the absorption heat pump 1 is controlled by a control device (not shown).

Next, referring to fig. 2, the absorber 10, which is one of the components of the absorption heat pump 1 (see fig. 1), will be described in detail. Fig. 2 is a sectional view around the absorber 10 of the absorption heat pump 1 shown in fig. 1. The absorber 10 is constituted: the heat transfer pipe 12 and the concentrated solution scattering nozzle 13 are housed in the cylinder 11, and a liquid chamber forming member 14Q as a heated medium chamber forming member is provided outside the cylinder 11. The liquid chamber forming member 14Q is a member in which the liquid chambers 14, which are the heated medium chambers, are formed, and the liquid chambers 14 supply the heated medium W to the heat transfer tubes 12 or collect the heated medium W from the heat transfer tubes 12. In the present embodiment in which the medium to be heated W is water, the liquid chamber 14 may be referred to as a water chamber instead. The cylinder 11 is typically formed in a transverse elongated shape when provided.

In the present embodiment, the heat transfer pipe 12 is formed linearly, but a plurality of heat transfer pipes are provided in the cylinder block 11. The flow path cross-sectional area of each heat transfer pipe 12 is formed uniformly over the entire length. In the present embodiment, all the heat transfer tubes 12 have the same diameter. The heat transfer pipe 12 is joined to one end of the transversely elongated cylinder 11 and the other end on the opposite side. The surface of the cylinder block 11 to which the heat transfer tubes 12 are joined is formed as a tube plate (heat transfer tube plate) having a hole through which the heat transfer tubes 12 can be inserted. The interiors of the heat transfer tubes 12 joined to the tube plates at both ends of the cylinder block 11 are not communicated with the interior of the cylinder block 11. In other words, the heating medium W flowing through the heat transfer tubes 12 is not mixed with the fluid (the absorbent S and the refrigerant V) flowing into and out of the cylinder 11 and existing outside the heat transfer tubes 12. In a specific example of the mode of joining the heat transfer tubes 12 to the tube plate, the heat transfer tubes 12 are expanded and fixed to holes formed in the tube plate of the cylinder block 11.

In the present embodiment, each heat transfer pipe 12 is arranged such that the axis thereof is horizontal. If it is considered that the heating medium liquid Wq is heated and boiled in the heat transfer tubes 12, it is also considered that the heat transfer tubes 12 are arranged such that the axis lines thereof are vertical. However, in the present embodiment, the heat transfer tubes 12 are arranged so that the axis thereof is horizontal, from the viewpoint of making the scattered absorption liquid S a thin liquid film and making contact with the outer surface of the heat transfer tubes 12 as much as possible. The heat transfer tubes 12 arranged with their axes horizontal have theoretically 100% horizontal components and 0% vertical components, and have no vertical components. The plurality of heat transfer pipes 12 provided in the cylinder block 11 are arranged in parallel with each other. Further, each heat transfer pipe 12 may be arranged such that: the axis is inclined with a rising slope within a range where the wetting of the absorption liquid S along the outer surface spreads to such an extent that a desired absorption heat can be obtained. The rising gradient is for causing the gas generated by boiling of the heating medium liquid Wq in the heat transfer pipe 12 to flow downstream.

The heat transfer pipe 12 disposed at the lowermost portion in the vertical direction among the heat transfer pipes 12 provided in the cylinder 11 is disposed at a position where a portion (space) for storing the dilute solution Sw therebelow is secured. With this configuration, during normal operation, the heat transfer tubes 12 do not enter the absorbent S, and the evaporator refrigerant vapor Ve is absorbed by the concentrated solution Sa wetting and spreading on the surfaces of the heat transfer tubes 12, so that the contact area between the concentrated solution Sa and the evaporator refrigerant vapor Ve can be increased, and the generated absorption heat can be quickly transferred to the medium W to be heated flowing through the heat transfer tubes 12, thereby accelerating recovery of the absorption capacity. On the other hand, the heat transfer pipe 12 disposed at the uppermost portion of the cylinder 11 is disposed at a position where a space in which the concentrated solution scattering nozzle 13 can be disposed is secured.

The liquid chamber forming members 14Q are attached to both surfaces (tube plates) of the cylinder 11 to which the end portions of the heat transfer tubes 12 are joined. The liquid chamber forming member 14Q is a rectangular parallelepiped member having one open surface, and is attached to the tube plate of the cylinder 11 so that the open surface covers one end of the plurality of heat transfer tubes 12 attached to the tube plate of the cylinder 11. The liquid chamber forming member 14Q may be provided with a detachable cover on a surface other than the surface of the opening (for example, a surface facing the surface of the opening). By attaching the liquid chamber forming member 14Q to the tube plate of the cylinder 11, a space surrounded by the liquid chamber forming member 14Q and the tube plate of the cylinder 11 becomes the liquid chamber 14. In the present embodiment, since the liquid chamber forming member 14Q is formed in a rectangular parallelepiped shape, the shape and size of the horizontal cross section of the liquid chamber 14 are constant without changing in the vertical direction. The liquid chamber 14 communicates with the inside of each heat transfer pipe 12. That is, the medium W flows into and out of the liquid chamber 14. In the case where a plurality of liquid chambers 14 are formed by dividing the inside of the liquid chamber forming member 14Q, partition plates 15 are provided inside the liquid chamber forming member 14Q. One end of the heat transfer pipe 12 through which the medium W to be heated flowing into the liquid chambers 14 flows and/or one end of the heat transfer pipe 12 through which the medium W to be heated flowing out of the liquid chambers 14 flows are communicated with each liquid chamber 14.

The partition plate 15 is provided with: the medium W to be heated is caused to flow into one or two or more heat transfer tubes 12 flowing out of one liquid chamber 14, and communicates with different liquid chambers 14 in the liquid chamber 14 on the opposite side. The heating target medium W flowing through the heat transfer tubes 12 and the liquid chambers 14 is configured to: from the liquid chamber 14 located at the most upstream, the liquid flows in one direction through the heat transfer pipe 12 communicating with the liquid chamber 14, and in the liquid chamber 14 on the opposite side, the flow direction is changed, and the liquid flows in the direction opposite to the one direction through the other heat transfer pipe 12 communicating with the liquid chamber 14 on the opposite side, and the configuration is such that: the whole becomes a jet of fluid that changes direction and travels through the cylinder 11. The partition plate 15 is provided to partition the liquid chamber 14 so that the medium W to be heated, which is a single fluid flow with the heat transfer tubes 12 and the liquid chamber 14 as a whole, flows from below to above with the cylinder 11 as a whole.

In the present embodiment, of the two liquid chamber forming members 14Q attached to the respective both surfaces of the cylinder 11, the liquid chamber 14 in one liquid chamber forming member 14Q is divided into the inlet liquid chamber 14e and the outlet liquid chamber 14f by one partition plate 15. The liquid chamber 14 in the other liquid chamber forming member 14Q is entirely the reversed liquid chamber 14r without the partition plate 15. The reversal liquid chamber 14r is a liquid chamber 14 that receives the medium W to be heated that flows inside the heat transfer pipe 12 through which the medium W to be heated flows (referred to as "heat transfer pipe 12A" for distinction) before flowing into the reversal liquid chamber 14r, and guides the received medium W to the heat transfer pipe 12 (referred to as "heat transfer pipe 12B" for distinction) that communicates with the reversal liquid chamber 14r other than the heat transfer pipe 12A, and the reversal liquid chamber 14r corresponds to a reversal portion. In the absorber 10 of the present embodiment, one reversal liquid chamber 14r is formed, and the plurality of heat transfer tubes 12 provided in the cylinder 11 are configured as two paths through the one reversal liquid chamber 14 r. Here, the "path" refers to a unit of a flow path through which a fluid flowing through a certain heat transfer tube 12 does not merge with a fluid flowing through another heat transfer tube 12 and flows without changing the flow direction by 180 degrees. The paths do not depend on the number of heat transfer tubes 12 as long as the fluid flowing through the heat transfer tubes 12 does not change the flow direction by 180 degrees and does not join in the middle.

The inlet liquid chamber 14e is a liquid chamber 14 that receives the heating medium liquid Wq flowing through the heating medium liquid pipe 82 and guides the received heating medium liquid Wq to the heat transfer pipe 12A. The inlet liquid chamber 14e is connected to one end of the heat transfer pipe 12A, but not to the other heat transfer pipe 12. The path formed by the heat transfer pipe 12A connected to the inlet liquid chamber 14e is a path into which the heating medium W first flows, and is referred to as a first path P1. The outlet liquid chambers 14f are liquid chambers 14 that receive the medium W to be heated flowing through the heat transfer pipe 12B and guide the received medium W to the outflow pipe 84. The outflow pipe 84 is connected to an upper portion (typically, the top portion) of the outlet liquid chamber 14 f. The outlet liquid chamber 14f is connected to one end of the heat transfer pipe 12B, but is not connected to the other heat transfer pipes 12. The path formed by the heat transfer pipe 12B connected to the outlet liquid chamber 14f is a path into which the heating medium W finally flows, and is referred to as a final path Pf. The absorber 10 of the present embodiment is composed of two paths, i.e., a first path P1 and a final path Pf, because the two paths are two paths.

The first path P1 and the final path Pf of the absorber 10 are configured to have uniform flow path cross-sectional areas. The flow path cross-sectional area of the path is the sum of the flow path cross-sectional areas of all the heat transfer tubes 12 constituting the path. The equalization of the flow path cross-sectional areas of the plurality of paths means that the ratio of the cross-sectional area in the path having the largest flow path cross-sectional area to the cross-sectional area in the path having the smallest flow path cross-sectional area (the largest cross-sectional area/the smallest cross-sectional area) is ideally 1, but strictly speaking, the ratio of the cross-sectional areas (the largest cross-sectional area/the smallest cross-sectional area) is included in the concept of being equalized even if the ratio of the cross-sectional areas (the largest cross-sectional area/the smallest cross-sectional area) deviates from 1 due to design or manufacturing constraints, errors, and the like, and includes, for example, the case where the ratio is 1.1 or less. As an example in which the respective paths cannot be made exactly the same area, there is a case where the shape of the region where the heat transfer tubes 12 are arranged (the shape of the outer edge of the heat transfer tubes 12 where a plurality are arranged) is an inverted trapezoid when viewed in the entire cylinder 11 in a cross section perpendicular to the axis of the heat transfer tubes 12 (in this case, the number of heat transfer tubes 12 in the upper path and the lower path cannot be made equal in many cases). In the present embodiment, since the first path P1 and the final path Pf connected to the single reversal liquid chamber 14r are configured to have uniform flow path cross-sectional areas, the flow rate of the heated medium W at the outlet of the first path P1 is equal to the flow rate of the heated medium W at the inlet of the final path Pf.

In the present embodiment, the horizontal cross-sectional area of the reversal liquid chamber 14r is formed smaller than the horizontal cross-sectional area of the outlet liquid chamber 14 f. The horizontal cross-sectional area of the reversal liquid chamber 14r should be set according to the ratio of the volume flow rate of the mixed heated medium Wm in the reversal liquid chamber 14r to the volume flow rate in the outlet liquid chamber 14f (volume flow rate of the reversal liquid chamber 14 r/volume flow rate of the outlet liquid chamber 14 f) from the viewpoint of suppressing an increase in the flow resistance of the heated medium W and the viewpoint of ensuring the flow rate of the heated medium W, but typically, the horizontal cross-sectional area of the reversal liquid chamber 14r is preferably substantially 0.8 times or less with respect to the horizontal cross-sectional area of the outlet liquid chamber 14 f. A purge discharge pipe 17 capable of discharging the heating medium liquid Wq is provided at a lower portion (typically, a bottom portion) of the reversal liquid chamber 14 r. A purge discharge valve 17v is disposed in the purge discharge pipe 17.

The concentrated solution distribution nozzle 13 housed in the cylinder 11 is disposed so as to extend over a wide range covering the heat transfer tubes 12 when viewed from vertically above, so that the concentrated solution Sa can be distributed to the heat transfer tubes 12 without fail. A concentrated solution pipe 35 connected to the concentrated solution distribution nozzle 13 penetrates one surface of the cylinder 11. As described above, although the plurality of heat transfer tubes 12 are arranged horizontally in the cylinder 11, the horizontal arrangement is not strictly required to be horizontal, and may be horizontal to such an extent that the flow of the heating medium W is not obstructed even if the direction of the flowing heating medium W changes from liquid to vapor in the heat transfer tubes 12 as a stream of fluid in the cylinder 11. However, from the viewpoint of increasing the amount of the concentrated solution Sa spread from the concentrated solution spreading nozzle 13 in contact with the outer surface of the heat transfer pipe 12, the closer to the level is more preferable. A dilute solution pipe 36 for guiding the dilute solution Sw stored at the bottom of the cylinder 11 to the regenerator 30 (see fig. 1) is connected to the bottom of the cylinder 11.

A heating medium liquid pipe 82 that guides the heating medium liquid Wq in the gas-liquid separator 80 to the cylinder 11 is connected to the inlet liquid chamber 14e, and the inlet liquid chamber 14e is the most upstream liquid chamber in the flow of the heating medium W in the cylinder 11. The supplementary water pipe 85 is connected to the heated medium liquid pipe 82. According to this configuration, the connection portion of the pipe through which the medium W to be heated flows into the cylinder 11 may be located at one position, and the configuration can be simplified, and the maintenance and inspection work when opening the liquid chamber 14 can be facilitated. An outflow pipe 84 for guiding the wet vapor (mixed heating medium Wm) generated in the cylinder 11 to the gas-liquid separator 80 is connected to the outlet liquid chamber 14 f. The structure is as follows: by connecting the liquid chamber 14 provided on the end surface of the cylinder 11 to the gas-liquid separator 80 via the heated medium liquid pipe 82 and the outflow pipe 84, the heated medium W can be circulated between the heat transfer pipe 12 disposed in the cylinder 11 and the gas-liquid separator 80. In the present embodiment, since the heating medium liquid pipe 82 and the outflow pipe 84 are configured as two paths, the liquid chamber 14 on the same side is connected to the cylinder 11, and the gas-liquid separator 80 is provided in the vicinity of the liquid chamber 14, whereby the gas-liquid separator 80 and the cylinder 11 can be connected in a short distance, the flow loss of the heating medium W can be reduced, and the manufacturing cost can be reduced. In addition, in the present embodiment, since a pump for pushing the heating medium liquid Wq in the gas-liquid separator 80 into the inlet liquid chamber 14e is not provided, the gas-liquid separator 80 is provided at a height at which a pressure capable of pushing the heating medium liquid Wq in the gas-liquid separator 80 into the inlet liquid chamber 14e can be obtained.

The pressing pressure required to press the heating medium liquid Wq in the gas-liquid separator 80 into the inlet liquid chamber 14e differs depending on the number of paths. When a predetermined number of heat transfer tubes 12 arranged in the cylinder 11 are divided into a plurality of paths and the flow path cross-sectional areas of the respective paths are equalized, if the number of paths is reduced, the number of heat transfer tubes 12 per path of the respective paths increases, the flow resistance of the heating medium W in the heat transfer tubes 12 decreases, and the number of reversal liquid chambers 14r decreases, the flow resistance decreases, and even with a small pressing pressure, the flow rate required for the heating medium W to flow into the first path P1 can be secured. Conversely, if the number of paths is increased, the number of heat transfer tubes 12 per path of each path is decreased, so that the flow resistance of the heating medium W in the heat transfer tubes 12 increases, and further, the number of reversal liquid chambers 14r is increased, so that the flow resistance increases, and the flow rate of the heating medium W flowing into the first path P1 decreases. Even in this case, it is sufficient if the pressure for pushing the heating medium liquid Wq in the gas-liquid separator 80 into the inlet liquid chamber 14e is sufficient, and the desired flow rate of the heating medium liquid Wq corresponding to the pressure can be secured. A sufficient pressing pressure can be obtained by providing a bubble pump effect generated by a difference in level between the group of heat transfer pipes 12 and the gas-liquid separator 80 provided above the group of heat transfer pipes 12 (the bottom of the gas-liquid separator 80 provided above the uppermost heat transfer pipe 12) or by providing a pressing pump (not shown), but in the present embodiment, the structure is simplified by using the bubble pump effect. Further, either one of the difference in height between the gas-liquid separator 80 and the group of heat transfer tubes 12 and the push-in pump or both of them may be used. The gas-liquid separator 80 is disposed at least above the heat transfer tubes 12 so as to obtain a flow rate of the heating medium W required by the bubble pump action. If the difference in height between the gas-liquid separator 80 and the heat transfer tube 12 group is enlarged, the bubble pump effect can be enlarged, and the circulation flow rate can be increased. In the present embodiment, the two paths are formed, so that the heating medium liquid Wq partially boils in the heat transfer tubes 12A of the first path P1.

Next, referring mainly to fig. 2, and appropriately to fig. 1, the action around the absorber 10 will be described. The concentrated solution Sa dispensed from the concentrated solution dispensing nozzle 13 is sent under pressure from the regenerator 30 by the solution pump 35 p. When the concentrated solution Sa is sprayed from the concentrated solution spraying nozzle 13, it falls by gravity and falls on the heat transfer pipe 12. The concentrated solution Sa first falls on the heat transfer tubes 12 disposed above in the cylinder 11, moves so as to fall on the heat transfer tubes 12 disposed below, moves to portions not in contact with the heat transfer tubes 12 disposed above, and drops on the surfaces of the heat transfer tubes 12, and wets and spreads along the surfaces of the heat transfer tubes 12. The concentrated solution Sa wetting and spreading along the surface of each heat transfer pipe 12 absorbs the evaporator refrigerant vapor Ve supplied from the evaporator 20, and heats the medium W to be heated flowing therein by the heat of absorption generated at this time. The rich solution Sa having absorbed the evaporator refrigerant vapor Ve becomes a lean solution Sw and is temporarily stored in the lower portion of the cylinder 11, and then is guided to the regenerator 30 through the lean solution pipe 36.

On the other hand, the heating medium liquid Wq from the gas-liquid separator 80 flows into the inlet liquid chamber 14e through the heating medium liquid pipe 82. At this time, since the inlet liquid chamber 14e is disposed below the storage portion 81 of the gas-liquid separator 80, the inlet liquid chamber 14e is filled with the heating medium liquid Wq by setting the liquid level in the normal operation in the storage portion 81 of the gas-liquid separator 80. The makeup water Ws is appropriately mixed with the heating medium liquid Wq flowing into the inlet liquid chamber 14e by the operation of the makeup water pump 86 before flowing into the inlet liquid chamber 14 e. From the viewpoint of efficiently evaporating the heating medium liquid Wq in each heat transfer pipe 12, the total mass flow rate of the heating medium liquid Wq flowing from the makeup water pipe 85 and the gas-liquid separator 80 into the inlet liquid chamber 14e is preferably: the mass flow rate of the heating medium vapor Wv generated in the cylinder 11 is preferably 2 times or more, and more preferably 10 times or less, from the viewpoint of suppressing an increase in the size of the gas-liquid separator 80. If the flow rate of the heating medium liquid Wq is large, the gas-liquid separation capability of the gas-liquid separator 80 may need to be increased (along with an increase in the size of the gas-liquid separator 80). On the other hand, if the flow rate of the heating medium liquid Wq is small, the heat transfer tubes 12 may be caused to flow in some cases, so that the heating medium liquid Wq does not flow into them. The mass flow rate of the heating medium liquid Wq flowing into the inlet liquid chamber 14e is 2 times or more the mass flow rate of the heating medium vapor Wv generated in the cylinder 11, and this means that: the flow rate of the heated medium liquid Wq flowing into the inlet liquid chamber 14e is at least half the mass flow rate of the heated medium liquid Wq flowing out of the outlet liquid chamber 14f in a liquid state. In this way, the sufficient pressing pressure for pressing the heating medium liquid Wq into the inlet liquid chamber 14e typically means: the inlet liquid chamber 14e can be filled with the heating medium liquid Wq, and the pressure of the mass flow rate (the appropriate flow rate) of the heating medium liquid Wq, which is 2 to 10 times the mass flow rate of the heating medium vapor Wv, can be pushed in.

The heating medium liquid Wq flowing into the inlet liquid chamber 14e flows into the heat transfer tubes 12A constituting the first path P1. At this time, since the inlet liquid chamber 14e is filled with the heating medium liquid Wq, the gas does not flow in, but the heating medium liquid Wq flows into all the heat transfer tubes 12A. The heating medium liquid Wq flowing through each heat transfer pipe 12A (the first path P1) is heated by the absorption heat generated when the evaporator refrigerant vapor Ve is absorbed by the rich solution Sa wetting and spreading on the outer surface of the heat transfer pipe 12A, and partially boils until reaching the reversal liquid chamber 14 r. Therefore, the liquid flows into the reversal liquid chamber 14r to be mixed with the medium to be heated Wm (a mixed fluid of the liquid to be heated Wq and the medium to be heated vapor Wv generated by evaporation of a part of the liquid to be heated Wq). The reason why the part of the heating medium liquid Wq boils in the first path P1 is to appropriately set the pressure of the heating medium liquid Wq into the inlet liquid chamber 14e, the number of paths in the cylinder 11, and the operating conditions. Since the mixed heating target medium Wm flows in the inside of the reversal liquid chamber 14r, the temperature is maintained at a temperature close to the saturation temperature. The mixed heating medium Wm flowing through each heat transfer pipe 12A and flowing into the reversal liquid chamber 14r rises while changing the direction of flow, and flows into each heat transfer pipe 12B constituting the final path Pf. In this way, the medium W to be heated flows from below to above as a whole. At this time, when the flow rate is small, the gas and the liquid may not flow together depending on the flow conditions, and as a result, the heat transfer tube 12B into which the liquid does not flow may be generated. The term "not to flow in liquid" strictly means not only that no liquid flows in, but also that a small amount of liquid flows in to such an extent that the amount of vapor generated is reduced even if a small amount of liquid flows in. In the heat transfer tubes 12 in which the inflow amount of liquid is smaller than the amount of vapor generated in the heat transfer tubes 12 leading to the largest amount of vapor generated among the amounts of vapor generated in the heat transfer tubes 12 in the same route, the amount of vapor generated is significantly smaller than the largest amount of vapor generated (to the extent that the amount of vapor generated is reduced beyond the allowable range). Therefore, from the viewpoint of avoiding the decrease in evaporation performance, it is more preferable to avoid the occurrence of the heat transfer tubes 12 having the decreased evaporation performance if the occurrence of the heat transfer tubes 12 into which a small amount of liquid flows is avoided as compared with the maximum amount of vapor generated in the heat transfer tubes 12 in the same path. That is, the inflow amount of a small amount of liquid to the extent that the amount of vapor generated is reduced means: including up to the inflow of liquid less than the maximum vapor production of the heat transfer tubes 12 in the same path. If the heat transfer pipe 12B into which the liquid does not flow is present, the efficiency of heat absorption in the heat transfer pipe 12B and heat transfer to the heating medium liquid Wq are deteriorated. However, in the absorber 10 of the present embodiment, the heat transfer tubes 12B into which the heating medium liquid Wq does not flow can be avoided for the following reason.

As described above, the absorber 10 of the present embodiment is configured such that: the horizontal sectional area of the reversal liquid chamber 14r is smaller than that of the outlet liquid chamber 14f, and the flow path sectional areas of the first path P1 and the final path Pf are configured equally. This can suppress the flow resistance of the heating medium W and allow the mixed heating medium Wm to uniformly flow into the heat transfer tubes 12B forming the final path Pf. In addition, the heated medium W flowing into the reversal liquid chamber 14r has a volume increased by an amount corresponding to evaporation of a part of the liquid into a gas, and the flow rate of the liquid is decreased, as compared with the heated medium W flowing into the inlet liquid chamber 14 e. In addition, the heated medium W in the outlet liquid chamber 14f has a volume further increased by an amount equivalent to further evaporation of the liquid into a gas, and the flow rate of the liquid is further decreased, as compared with the heated medium W in the reversal liquid chamber 14 r. Therefore, the flow velocity at which the medium W to be heated in the inside of the reversal liquid chamber 14r rapidly rises can be realized by making the horizontal cross-sectional area of the reversal liquid chamber 14r smaller than the horizontal cross-sectional area of the outlet liquid chamber 14f by an amount equivalent to the volume of the medium W to be heated smaller than the outlet liquid chamber 14 f. When the ascending flow velocity of the medium W to be heated in the reversing liquid chamber 14r is accelerated, the liquid and the vapor in the medium Wm are mixed together in the reversing liquid chamber 14r, the flow is nearly uniform, and when the mixed medium Wm flows from the reversing liquid chamber 14r into the heat transfer tubes 12B constituting the final path Pf, the liquid in the mixed medium Wm uniformly flows into the heat transfer tubes 12B of the final path Pf. Assuming that the flow rate of mixing the heated medium Wm is decreased, there are the following cases: due to the flow condition, the liquid and the vapor in the mixed heating medium Wm are not integrated, and the heat transfer pipe 12B in which the liquid in the mixed heating medium Wm does not flow or the flow rate of the liquid flowing in is small appears. However, if the medium W to be heated in the heat transfer pipe 12 is: as the flow velocity increases further downstream of the flow in which the flow rate of the liquid relatively decreases, the flow velocity of the heating medium W is accelerated in the order of the inflow velocity into the heat transfer tubes 12A of the first path P1, the outflow velocity from the heat transfer tubes 12A of the first path P1, the inflow velocity into the heat transfer tubes 12B of the final path Pf, and the outflow velocity from the heat transfer tubes 12B of the final path Pf, so that the occurrence of heat transfer tubes 12B in which the heating medium liquid Wq does not flow or the occurrence of heat transfer tubes 12B in which the flow rate of the inflow heating medium liquid Wq is small and evaporation performance decreases can be avoided, and a decrease in efficiency of the transfer of the absorption heat to the heating medium W can be suppressed. At the same time, evaporation residues and the like generated by evaporation of the heating medium liquid Wq can be prevented from adhering to and remaining on the inner surface of the heat transfer tube 12. Further, by configuring the horizontal cross-sectional area of the reversal liquid chamber 14r to be smaller than the horizontal cross-sectional area of the outlet liquid chamber 14f, the internal volume of the reversal liquid chamber 14r can be compressed, the holding amount of the heated medium W in the absorber 10 can be reduced, the heating amount of the heated medium W at the time of starting the absorption heat pump 1 can be reduced, and the thermal efficiency can be improved. Similarly, if the horizontal cross-sectional area of the inlet liquid chamber 14e is made to be approximately the same as or smaller than the horizontal cross-sectional area of the reversal liquid chamber 14r connected to the outlet of the first path P1, the holding amount of the heating target medium W can be further reduced, and the thermal efficiency can be improved.

The medium W to be heated flowing from the reversing liquid chamber 14r into each heat transfer tube 12B constituting the final path Pf is heated by absorption heat generated when the evaporator refrigerant vapor Ve is absorbed by the rich solution Sa wetting and spreading on the outer surface of the heat transfer tube 12B when each heat transfer tube 12B flows. The heating medium W flowing through and heated in each heat transfer pipe 12B boils until approximately 10% to 50% of the heating medium liquid Wq flowing into the inlet liquid chamber 14e reaches the outlet liquid chamber 14 f. The medium W to be heated, which is heated when flowing through each heat transfer pipe 12, is a mixed medium Wm in a gas-liquid mixed state, and reaches the outlet liquid chamber 14 f. The ratio of the medium vapor to be heated Wv in the mixed medium to be heated Wm in the outlet liquid chamber 14f is larger than the ratio of the medium vapor to be heated Wv in the mixed medium to be heated Wm in the reversal liquid chamber 14 r. Since the mixed heating target medium Wm flows in the outlet liquid chamber 14f, the temperature is maintained at a temperature close to the saturation temperature. The mixed heating medium Wm in the outlet liquid chamber 14f flows out through the outflow pipe 84. The mixed heating medium Wm flowing out of the outlet liquid chamber 14f flows into the gas-liquid separator 80 through the outflow pipe 84 by the bubble pump effect. The mixed heating medium Wm flowing into the gas-liquid separator 80 collides with the baffle 80a to be separated into gas and liquid, and is separated into the heating medium liquid Wq and the heating medium vapor Wv. The separated heating medium vapor Wv flows through the heating medium vapor pipe 89 toward a vapor utilization place outside the absorption heat pump 1. On the other hand, the heating medium liquid Wq separated in the gas-liquid separator 80 is stored in the storage portion 81 at the lower part of the gas-liquid separator 80. The heating medium liquid Wq stored in the storage portion 81 flows through the heating medium liquid pipe 82. The heating medium liquid Wq flowing through the heating medium liquid pipe 82 joins the makeup water Ws from the makeup water pipe 85 as necessary, and flows into the inlet liquid chamber 14e, and the above-described operation is repeated below.

As described above, according to the absorber 10 of the present embodiment, the plurality of heat transfer tubes 12 are divided into two paths, the flow path sectional areas of the first path P1 and the final path Pf are equally configured, and the horizontal sectional area of the inside of the reversing liquid chamber 14r is configured to be smaller than the horizontal sectional area of the outside liquid chamber 14f, so that the flow velocity of the heating medium W boiling in a part of the liquid in the first path P1 increases toward the downstream side of the flow, and the flow of the heating medium W in the reversing liquid chamber 14r becomes nearly uniform, and it is possible to avoid the occurrence of heat transfer tubes 12 into which the heating medium liquid Wq does not flow, or the occurrence of heat transfer tubes 12 into which the flow rate of the heating medium liquid Wq flowing in is small and evaporation performance is deteriorated. Further, since the reversing liquid chamber 14r is formed by one and two paths, the heating medium liquid Wq is also easily boiled in the heat transfer pipe 12A constituting the first path P1, and the bubble pump effect can be improved.

In the above description, the reversal liquid chamber 14r is formed in one, and the plurality of heat transfer tubes 12 are formed of two paths, but may be formed of three or more paths. In the case of being constituted by three or more paths, the reversal liquid chambers 14r (reversal portions) are formed in the number of subtracting 1 from the number of paths. In this case, although a plurality of the reversal liquid chambers 14r are formed, the liquid chambers 14 on the upstream side in the flow direction of the heating target medium W may have a smaller horizontal cross-sectional area. Fig. 3 shows an example of a structure in which the horizontal cross-sectional area decreases toward the liquid chamber 14 on the upstream side in the flow direction. The absorber 10A shown in fig. 3 is configured as four paths, and three reversal liquid chambers 14r are provided. The absorber 10A is provided with a detachable cover 14Qc on a surface of the liquid chamber forming member 14Q facing the tube plate. A filling member 14S is attached to the inside of the cover 14Qc, and the filling member 14S protrudes in a convex shape toward the inside of the inlet liquid chamber 14e and the inverted liquid chamber 14r, thereby reducing the internal volume of the liquid chamber 14. The size of the embedding member 14S protruding into the liquid chamber 14 is adjusted according to the liquid chamber 14. Thus, in the present modification, the liquid chamber 14 on the upstream side in the flow direction is configured such that the horizontal cross-sectional area is smaller for the same liquid chamber forming member 14Q: the horizontal sectional area of the liquid chamber 14 gradually decreases toward the flow direction upstream side. In the absorber 10A configured as described above, the flow velocity of the medium W to be heated which rises in each of the reversal liquid chambers 14r can be set to a velocity at which the liquid and the vapor in the medium W to be heated are mixed and flow together, and even if there are a plurality of reversal liquid chambers 14r, the liquid in which the medium W to be heated is mixed can be made to flow uniformly into the heat transfer pipes 12 connected to the respective reversal liquid chambers 14r while suppressing the flow resistance of the medium W to be heated. Further, the internal volume of each of the reversal liquid chambers 14r can be compressed, the amount of the medium W held in the absorber 10A can be reduced, the amount of heat of the medium W when the absorption heat pump 1 is started can be reduced, and the thermal efficiency can be improved.

In addition, when a predetermined number of heat transfer tubes 12 arranged in the cylinder 11 are divided into a plurality of paths and the flow path cross-sectional areas of the respective paths are equalized, if the number of paths is increased, the number of heat transfer tubes 12 per path is decreased, and the range of increase in the flow velocity of the heating medium W that accelerates toward the downstream side of the flow can be increased, but from the viewpoint of suppressing an increase in flow resistance, it is preferable that 10 paths or less are used, and 4 paths, or 3 paths or 5 paths that are odd numbers are used. On the other hand, when the number of paths is reduced, the number of heat transfer tubes 12 per path increases, and the flow resistance of the heating medium W in the heat transfer tubes 12 decreases, so that there is an advantage that the flow rate of the heating medium W can be increased by the bubble pump effect. In the final path Pf, a part of the heating medium liquid Wq boils and flows out as the mixed heating medium Wm to the outlet liquid chamber 14f, regardless of whether the number of paths is large or small. Further, the flow velocity of the mixed heating medium Wm flowing in the heat transfer tubes 12 increases as the downstream path in which the amount of liquid in the mixed heating medium Wm decreases, and the decrease in the flow rate of the heating medium liquid Wq flowing into the heat transfer tubes 12 is suppressed, so that the decrease in the evaporation performance of the heat transfer tubes 12 can be suppressed. Further, depending on the operating conditions and the number of paths, unlike the case of the absorber 10 of the present embodiment, there are cases where a part of the heating medium liquid Wq does not boil in the first path P1, but if the reversal liquid chamber 14r into which the non-boiling heating medium liquid Wq flows is filled with the heating medium liquid Wq and an appropriate flow rate of the heating medium liquid Wq is secured as in the case of the inlet liquid chamber 14e, a part of the heating medium liquid Wq may not necessarily boil in the first path P1. Even when the part of the heating medium liquid Wq does not boil in the path on the downstream side of the first path P1 and on the upstream side of the final path Pf, if the inversion liquid chamber 14r into which the non-boiling heating medium liquid Wq flows is filled with the heating medium liquid Wq and an appropriate flow rate of the heating medium liquid Wq is secured, the part of the heating medium liquid Wq may not boil in the path on the downstream side of the first path P1 and on the upstream side of the final path Pf. Here, the term "a part of the heating medium liquid Wq does not boil" means that: the case where the heating medium liquid Wq is not boiled at all includes a case where even in the case of boiling, bubbles that are boiled are actually mixed in the flow of the liquid in small particles (particles that are actually small enough to be regarded as a liquid) and flow.

In the above description, the plurality of paths are formed to have uniform flow path cross-sectional areas, but may be formed to have the same degree. The flow path cross-sectional areas of the respective paths are the same: the term "uniform area" also includes a case where the ratio of the flow path cross-sectional areas of the respective paths is within a predetermined range. The ratio of the flow path cross-sectional areas of the respective paths within a predetermined range means: the flow channel cross-sectional area ratio is within a range of flow velocity that can provide the medium W with a flow velocity that can avoid the occurrence of heat transfer tubes 12 into which the heating medium liquid Wq does not flow, or the occurrence of heat transfer tubes 12 in which the flow rate of the inflow heating medium liquid Wq is small and evaporation performance is reduced. As an example of the predetermined range, depending on the conditions, a ratio of a cross-sectional area of a path having a largest flow path cross-sectional area to a cross-sectional area of a path having a smallest flow path cross-sectional area (maximum cross-sectional area/minimum cross-sectional area) is 1.5 or less. The respective paths having the flow path cross-sectional areas within the range of the ratio are not restricted in the order of arrangement from the upstream to the downstream, and the order of arranging the paths is not related to the flow path cross-sectional area. With this configuration, the occurrence of the heat transfer tubes 12 into which the heating medium liquid Wq does not flow or the occurrence of the heat transfer tubes 12 in which the evaporation performance is reduced due to a small flow rate of the heating medium liquid Wq flowing into the heat transfer tubes 12 can be avoided, so that the heat transfer efficiency of the heat transfer tubes 12 can be improved, the increase in the flow resistance of each path can be suppressed, and the flow rate of the heating medium liquid Wq circulating between the heat transfer tubes 12 and the gas-liquid separator 80 can be sufficiently ensured.

In the above description, the horizontal cross-sectional area of the reversing liquid chamber 14r is smaller than the horizontal cross-sectional area of the outlet liquid chamber 14f, but the horizontal cross-sectional area of the reversing liquid chamber 14r may not be smaller than the horizontal cross-sectional area of the outlet liquid chamber 14f if a flow rate can be given to such an extent that the occurrence of the heat transfer tubes 12 into which the heating medium W does not flow or the occurrence of the heat transfer tubes 12 into which the flow rate of the heating medium Wq is small and evaporation performance is reduced can be avoided.

In the above description, the reversing section is constituted by the reversing liquid chamber 14r, and the reversing liquid chamber 14r supplies the medium W to be heated received from the plurality of heat transfer tubes 12 to the plurality of heat transfer tubes 12, but as shown in fig. 4, the medium W to be heated received from one heat transfer tube 12 may be formed into a U-shaped tubular configuration to be supplied to one heat transfer tube 12. In the absorber 10B of the modification shown in fig. 4, one heat transfer pipe 12A constituting the first path P1 and one heat transfer pipe 12B constituting the final path Pf are connected by one inversion pipe 14P. The inversion tubes 14p are provided in the number of heat transfer tubes 12 in each path. In the absorber 10B shown in fig. 4, the flow direction of the medium W to be heated flowing through the heat transfer pipe 12A constituting the first path P1 and the flow direction of the medium W to be heated flowing through the heat transfer pipe 12B constituting the final path Pf are changed by 180 degrees, and therefore the first path P1 and the final path Pf are different paths. In the absorber 10B shown in fig. 4, since the inlet liquid chambers 14e are filled with the heating medium liquid Wq, it is possible to reliably avoid the occurrence of the heat transfer tubes 12 into which the heating medium liquid Wq does not flow, or the occurrence of the heat transfer tubes 12 into which the flow rate of the heating medium liquid Wq flowing in is small and the evaporation performance is reduced.

In the above description, the supplementary water pipe 85 is connected to the heated medium liquid pipe 82, but may be configured such that: the makeup water pipe 85 is connected to the gas-liquid separator 80, and the makeup water Ws merges with the heated medium liquid Wq in the gas-liquid separator 80.

In the above description, the absorption heat pump 1 is described as a single stage, but the absorption heat pump 1 may be configured as a plurality of stages. Fig. 5 illustrates a structure of a two-stage heating type absorption heat pump 1A. For the absorption heat pump 1A, the absorber 10 and the evaporator 20 in the absorption heat pump 1 shown in fig. 1 are divided into: a high-temperature absorber 10H and a high-temperature evaporator 20H on the high-temperature side, and a low-temperature absorber 10L and a low-temperature evaporator 20L on the low-temperature side. The internal pressure of the high temperature absorber 10H is higher than the internal pressure of the low temperature absorber 10L, and the internal pressure of the high temperature evaporator 20H and the internal pressure of the low temperature evaporator 20L are higher. The high temperature absorber 10H and the high temperature evaporator 20H communicate with each other at the upper portion thereof so that the vapor of the refrigerant V in the high temperature evaporator 20H can move to the high temperature absorber 10H. The low temperature absorber 10L and the low temperature evaporator 20L communicate with each other at the upper portion thereof so that the vapor of the refrigerant V in the low temperature evaporator 20L can move to the low temperature absorber 10L. The heating medium liquid Wq is heated by the high temperature absorber 10H. The heat source hot water h is introduced into the low-temperature evaporator 20L. The low-temperature absorber 10L is constituted by: the refrigerant liquid Vf in the high temperature evaporator 20H is heated by the absorption heat when the vapor of the refrigerant V transferred from the low temperature evaporator 20L is absorbed by the absorption liquid S, the vapor of the refrigerant V is generated in the high temperature evaporator 20H, and the generated vapor of the refrigerant V in the high temperature evaporator 20H heats the heating medium liquid Wq by the absorption heat when the vapor moves to the high temperature absorber 10H and is absorbed by the absorption liquid S in the high temperature absorber 10H. Thus, in the absorption heat pump 1A, the structure around the absorber 10 shown in fig. 2 is typically applied to the high-temperature absorber 10H. The structure around the absorber 10 shown in fig. 2 is typically applied to an absorber having the highest internal temperature and internal pressure even in the case of an absorption heat pump having three or more stages. However, in the absorption heat pump 1A, the refrigerant V flowing through the heat transfer pipe in the low-temperature absorber 10L corresponds to the medium to be heated, in addition to the medium to be heated W. Since the medium to be heated flowing in the heat transfer pipe is the refrigerant V, the low-temperature absorber 10L can perform the setting of the purge drain pipe of the medium to be heated (refrigerant V), and the purge drain operation. In addition, in the

absorption heat pumps

1 and 1A, the absorber 10A shown in fig. 3 and the absorber 10B shown in fig. 4 can be applied instead of the absorber 10 shown in fig. 2.

Claims

1. An absorber is arranged on an absorption heat pump, the absorption heat pump absorbs the heat of a heat source fluid introduced by the absorption heat pump circulation of absorption liquid and refrigerant, the absorber is characterized in that,

a plurality of heat transfer tubes through which a medium to be heated at least a part of which is liquid flows,

the absorber further includes a reversing portion that guides the medium to be heated flowing inside the heat transfer pipe to another heat transfer pipe so as to flow in a reverse direction inside another heat transfer pipe,

the plurality of heat transfer pipes are configured as a plurality of paths by the inversion portion,

the plurality of paths are respectively configured such that the flow path cross-sectional areas are the same,

the absorber is configured to: heating the medium to be heated flowing inside the heat transfer tubes by absorption heat generated when the absorption liquid absorbs the vapor of the refrigerant outside the heat transfer tubes, thereby boiling the liquid of the medium to be heated,

the absorber further includes a gas-liquid separator that separates a liquid of the heated medium from a gas,

the plurality of paths are configured to include a first path that is a path into which the heated medium first flows, and a final path that is a path into which the heated medium finally flows,

the gas-liquid separator is configured to: introducing the medium to be heated in a gas-liquid mixed state from the final path, supplying the separated gas medium to a vapor utilization place outside the absorption heat pump, and supplying the separated liquid medium to the first path,

the pressure of the heated medium of the liquid supplied from the gas-liquid separator to the first path is given by a difference in height between the heat transfer pipe and the gas-liquid separator provided above the heat transfer pipe,

a predetermined flow rate can be secured in the flow rate of the medium to be heated flowing into the first path by the pressing pressure of the medium to be heated supplied to the first path,

the gas-liquid separator is arranged at the following height: the heated medium of the liquid flowing into the first path is given a height of pressure capable of pressing a mass flow rate of the heated medium of the liquid that is 2 times or more and 10 times or less a mass flow rate of the heated medium of the gas generated between the first path and the final path into the first path,

the reverse rotation portion is composed of one,

the heated medium is water.

2. The absorber of claim 1,

the plurality of paths are configured to have a uniform flow path cross-sectional area.

3. The absorber of claim 1,

the plurality of paths are respectively configured to: the ratio of the flow path cross-sectional areas is within a predetermined range in which the occurrence of heat transfer tubes into which the liquid of the medium to be heated does not flow can be avoided.

4. The absorber of claim 1,

the plurality of paths are respectively configured to: the ratio of the flow path cross-sectional areas is within a predetermined range in which the occurrence of the heat transfer pipe into which the liquid of the heating medium flows can be prevented at a small flow rate to the extent that the decrease in the amount of vapor generated in the heating medium exceeds the allowable range.

5. The absorber according to any one of claims 1 to 4,

the horizontal cross-sectional area of the inversion portion is configured as follows: is smaller than a horizontal sectional area of an outlet liquid chamber connected to an outlet side of a path into which the heated medium flows last among the plurality of paths.

6. The absorber according to any one of claims 1 to 4,

the structure is as follows: a part of the liquid of the medium to be heated boils inside the heat transfer pipe that constitutes a path into which the medium to be heated first flows out of the plurality of paths.

7. An absorption heat pump is characterized by comprising:

an absorber according to any one of claims 1 to 6; and

and a regenerator that introduces and heats the absorption liquid, which has a decreased concentration by absorbing the vapor of the refrigerant in the absorber, and that separates the refrigerant to increase the concentration of the absorption liquid.