Heat exchange unit for absorption refrigeration machine, absorption refrigeration machine and heat exchange method

Abstract

The heat exchange unit (1) for an absorption refrigeration machine of the present invention comprises a first container (5a), a first heat-conducting tube group (6f), a first dripper (7a), a second container (5b), a second heat-conducting tube group (6s), and a second dripper (7b). The first dripper (7a) has a plurality of first dripping parts (74a) arranged along the length direction of the first heat-conducting tube (6a). The refrigerant liquid drips from the first dripping parts (74a) toward the first heat-conducting tube group (6f). The second dripper (7b) has a plurality of second dripping parts (74b) arranged along the length direction of the second heat-conducting tube (6b). The solution drips from the second dripping parts (74b) toward the second heat-conducting tube group (6s). The interval (P2) between adjacent second dripping parts (74b) in the length direction of the second heat-conducting tube (6b) is smaller than the interval (P1) between adjacent first dripping parts (74a) in the length direction of the first heat-conducting tube (6a).

Description

Technical Field

[0001] The invention relates to a heat exchange unit for an absorption refrigeration machine, an absorption refrigeration machine and a heat exchange method. Background Art

[0002] Conventionally, there is known a liquid spreading device for an absorption refrigerator having a structure for dripping liquid.

[0003] For example, the liquid spreading device described in Patent Document 1 includes a tray and a guide body. The tray has a long strip structure for receiving the liquid to be spread. The guide body has a plurality of dripping ports arranged along the length direction, from which the liquid drips. The guide body is provided with an intercepting wall, which includes a long-side weir portion and a short-side weir portion. The long-side weir portion intercepts the long-side open end of the liquid receiving portion of the guide body. The short-side weir portion intercepts the short-side open end of the liquid receiving portion.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 7-4782 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] The present invention provides a heat exchange unit for an absorption refrigerator, which is advantageous for improving the wettability of a solution having a higher viscosity than a refrigerant liquid in an evaporator of the absorption refrigerator in a heat transfer pipe.

[0009] Solutions to Problems

[0010] The heat exchange unit for an absorption refrigeration machine in the present invention comprises:

[0011] a first container;

[0012] a first heat-conducting pipe group including a plurality of first heat-conducting pipes arranged in multiple layers and multiple rows inside the first container;

[0013] a first dripper having a plurality of first dripping parts arranged along the length direction of the first heat transfer tube and dripping the refrigerant liquid from the first dripping parts toward the first heat transfer tube group;

[0014] a second container;

[0015] a second heat-conducting pipe group including a plurality of second heat-conducting pipes arranged in multiple layers and multiple rows inside the second container; and

[0016] The second dripper has a plurality of second dripping parts arranged along the length direction of the second heat transfer tube, and drips the solution from the second dripping parts toward the second heat transfer tube group.

[0017] The interval between the second dripping portions adjacent to each other in the longitudinal direction of the second heat transfer tube is smaller than the interval between the first dripping portions adjacent to each other in the longitudinal direction of the first heat transfer tube.

[0018] Effects of the Invention

[0019] The absorption chiller heat exchange unit of the present invention facilitates the formation of a uniform liquid film on the second heat transfer pipe by reducing the spacing between the droplets of solution dripping from the plurality of second dripping portions. Therefore, the absorption chiller heat exchange unit of the present invention is advantageous for improving the wettability of the heat transfer pipe with a solution having a higher viscosity than the refrigerant liquid in the evaporator of the absorption chiller. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram showing the heat exchange unit according to the first embodiment.

[0021] Figure 2A It shows Figure 1 A cross-sectional view of a first dripper and a first heat conducting pipe of a heat exchange unit.

[0022] Figure 2B It shows Figure 1 FIG. 5 is a diagram showing a cross section of a first dripper and a first heat pipe of a heat exchange unit.

[0023] Figure 3A It shows Figure 1 A cross-sectional view of a second dripper and a second heat conducting pipe of a heat exchange unit.

[0024] Figure 3B It shows Figure 1 FIG. 5 is a diagram showing a cross section of a second dripper and a second heat pipe of a heat exchange unit.

[0025] Figure 4 It is a figure which shows the cross section of the dripper and the heat transfer pipe of a reference example.

[0026] Figure 5A This is a diagram showing a cross section of a second dripper and a second heat transfer pipe of a heat exchange unit according to Embodiment 2 at time t.

[0027] Figure 5B This is a diagram showing a cross section of the second dripper and the second heat transfer pipe of the heat exchange unit according to the second embodiment at time t+Δt.

[0028] Figure 6A 1 and 2 are diagrams showing a cross section of a dripper and a heat transfer pipe of a reference example at time t.

[0029] Figure 6B1 and 2 are diagrams showing a cross section of a dripper and a heat transfer pipe of a reference example at time t+Δt.

[0030] Figure 7 This is a diagram showing an absorption refrigerator according to a third embodiment. DETAILED DESCRIPTION

[0031] (Foundation forming the basis of the present invention)

[0032] Until the present inventors came up with the present invention, as a technology for improving the wettability of the liquid in the heat transfer pipe in an absorption chiller, devices of the dispersion type and the spray type were considered. It is difficult to adapt the spray type device to the absorber of the absorption chiller. From the perspective of commonality of components in the evaporator and the absorber, a dispersion type device is generally used in both the evaporator and the absorber. Under such circumstances, the present inventors focused on the fact that the wettability of the solution in the heat transfer pipe of the absorber is lower than the wettability of the refrigerant liquid in the heat transfer pipe of the evaporator, and came up with the idea of ​​constructing a dropper in the absorber in a manner specifically for dripping the solution. In order to realize their idea, the present inventors found that there is a problem that a high-viscosity solution is difficult to spread when it adheres to the heat transfer pipe by dripping, and in order to solve this problem, they came up with the subject matter of the present invention.

[0033] Therefore, the present invention provides a heat exchange unit for an absorption refrigerator that is advantageous in improving the wettability of a solution having a higher viscosity than the refrigerant liquid in an evaporator of an absorption refrigerator in a heat transfer pipe.

[0034] The following describes the embodiments in detail with reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical structures may be omitted. It should be noted that the drawings and the following description are provided to enable those skilled in the art to fully understand the present invention and are not intended to limit the subject matter described in the patent technical solutions.

[0035] (Implementation 1)

[0036] Below, use Figure 1 、 Figure 2A 、 Figure 2B 、 Figure 3A as well as Figure 3B Embodiment 1 will be described. In the accompanying drawings, the negative z-axis direction corresponds to the direction of gravity. The x-axis, y-axis, and z-axis are orthogonal to each other.

[0037] [1-1. Structure]

[0038] like Figure 1As shown, the absorption refrigeration heat exchange unit 1 includes a first container 5a, a first heat transfer pipe group 6f, a first dripper 7a, a second container 5b, a second heat transfer pipe group 6s, and a second dripper 7b. The first heat transfer pipe group 6f includes a plurality of first heat transfer pipes 6a arranged in multiple layers and rows inside the first container 5a. Figure 2A as well as Figure 2B As shown, the first dripper 7a has a plurality of first dripping parts 74a arranged along the longitudinal direction (X-axis direction) of the first heat transfer tube 6a. In addition, the first dripper 7a drips the refrigerant liquid from the first dripping parts 74a toward the first heat transfer tube group 6f. The second heat transfer tube group 6s includes a plurality of second heat transfer tubes 6b arranged in multiple layers and multiple rows inside the second container 5b. Figure 3A as well as Figure 3B As shown, the second dripper 7b has a plurality of second dripping parts 74b arranged along the length direction of the second heat transfer tube 6b. In addition, the second dripper 7b drips the solution from the second dripping parts 74b toward the second heat transfer tube group 6s. Figure 2B as well as Figure 3B As shown, the interval P2 between adjacent second dripping portions 74b in the longitudinal direction (X-axis direction) of the second heat transfer tube 6b is smaller than the interval P1 between adjacent first dripping portions 74a in the longitudinal direction of the first heat transfer tube 6a.

[0039] As long as the interval P2 is smaller than the interval P1, the value of the ratio of the interval P2 to the interval P1 (P2 / P1) is not limited to a specific value.

[0040] The first dripper 7a is disposed above the first heat transfer tube group 6f in the direction of gravity, and the second dripper 7b is disposed above the second heat transfer tube group 6s in the direction of gravity.

[0041] like Figure 1 As shown, heat exchange unit 1 includes, for example, evaporator 2, absorber 3, and vapor flow path 4. Heat exchange unit 1 is filled with a refrigerant and a solution. Evaporator 2 generates refrigerant vapor. Absorber 3 absorbs the refrigerant vapor generated by evaporator 2. Vapor flow path 4 guides the refrigerant vapor generated by evaporator 2 to absorber 3.

[0042] Evaporator 2 is a shell-and-tube heat exchanger. This is a typical distributed-type shell-and-tube heat exchanger. For example, when using a refrigerant such as water, whose saturated vapor pressure at room temperature (20°C ± 15°C) is negative, the refrigerant head's influence on the evaporation pressure in a flooded shell-and-tube heat exchanger is likely to be significant. Therefore, when using a refrigerant such as water, it is advantageous to use a distributed-type shell-and-tube heat exchanger for evaporator 2.

[0043] The evaporator 2 includes a first container 5a, a first heat-conducting tube group 6f, and a first dripper 7a. The first container 5a is, for example, a container having thermal insulation and pressure resistance. A refrigerant liquid is stored in the first container 5a. Furthermore, the first container 5a isolates the refrigerant vapor inside the first container 5a from external gases such as air at atmospheric pressure. In the first heat-conducting tube group 6f, a plurality of first heat-conducting tubes 6a are arranged parallel to one another and in multiple layers in the direction of gravity. The plurality of first heat-conducting tubes 6a are arranged, for example, in a square grid or a rectangular grid in a plane perpendicular to the longitudinal direction of the first heat-conducting tubes 6a. The first heat-conducting tubes 6a are made of copper or stainless steel. Grooves may also be formed on the inner and outer surfaces of the first heat-conducting tubes 6a.

[0044] like Figure 2A as well as Figure 2B As shown, the first dripper 7a includes a tray 71a, a retaining member 73a, and a slit member 77a. A storage space 70a is formed within the tray 71a, and refrigerant liquid 18 is stored in the storage space 70a. The tray 71a is elongated, for example, extending parallel to the length of the first heat transfer tube 6a. A plurality of distribution holes 72a are formed at the bottom of the tray 71a. The distribution holes 72a are arranged parallel to the length of the first heat transfer tube 6a. The retaining member 73a is joined to the bottom surface of the tray 71a. The retaining member 73a has an inclined surface directly below the distribution holes 72a. Furthermore, the retaining member 73a has a side surface connected to the inclined surface and extending toward the first heat transfer tube group 6f. The end of this side surface forms a first dripping portion 74a. The first dripping portion 74a is, for example, plate-shaped. The first dripping portion 74a has a first front end portion 75a that tapers toward the first heat transfer tube group 6f. The first front end portion 75a has an edge or vertex. The first front end portion 75a is, for example, plate-shaped. The slit member 77a is joined to the side surface of the retaining member 73a, and a groove 78a is formed between the slit member 77a and the side surface of the retaining member 73a. Figure 2B As shown, the slit member 77a has openings 76a formed near the first dripping portion 74a. Therefore, the plurality of openings 76a are arranged along the longitudinal direction of the first heat transfer pipe 6a.

[0045] The tray 71a, the holder 73a, and the slit member 77a can each be manufactured by, for example, press-working a stainless steel plate. The first dripper 7a can be manufactured by welding the tray 71a, the holder 73a, and the slit member 77a.

[0046] The absorber 3 is a shell and tube heat exchanger. The absorber is a typical distributed shell and tube evaporator.

[0047] The absorber 3 includes a second container 5b, a second heat-conducting tube group 6s, and a second dripper 7b. The second container 5b is, for example, a container with thermal insulation and pressure resistance. A solution is stored in the second container 5b. Furthermore, the second container 5b isolates the refrigerant vapor inside the second container 5b from external air, such as air at atmospheric pressure. In the second heat-conducting tube group 6s, multiple second heat-conducting tubes 6b are arranged parallel to each other and in multiple layers in the direction of gravity. The multiple second heat-conducting tubes 6b are arranged, for example, in a square or rectangular grid in a plane perpendicular to the longitudinal direction of the second heat-conducting tubes 6b. The second heat-conducting tubes 6b are made of copper or stainless steel. Grooves are formed on the inner and outer surfaces of the second heat-conducting tubes 6b.

[0048] like Figure 3A as well as Figure 3B As shown, the second dripper 7b includes a tray 71b, a retaining member 73b, and a slit member 77b. A storage space 70b is formed within the tray 71b, and the solution 26 is stored in the storage space 70b. The tray 71b extends, for example, parallel to the length of the second heat-conducting tube 6b. A plurality of distribution holes 72b are formed on the bottom of the tray 71b. These distribution holes 72b are arranged, for example, parallel to the length of the second heat-conducting tube 6b. The retaining member 73b is joined to the bottom surface of the tray 71b. The retaining member 73b has an inclined surface directly below the distribution holes 72b. Furthermore, the retaining member 73b has a side surface connected to the inclined surface and extending toward the second heat-conducting tube group 6s. The end of this side surface forms a second dripping portion 74b. The second dripping portion 74b has a second front end portion 75b that tapers toward the second heat-conducting tube group 6s. The second dripping portion 74b is, for example, plate-shaped. The second front end portion 75b has a ridge or vertex. The second front end portion 75b is, for example, plate-shaped. The slit member 77b is joined to the side surface of the retaining member 73b, and a groove 78b is formed between the slit member 77b and the side surface of the retaining member 73b. Figure 3B As shown in FIG. 1 , the slit member 77b has openings 76b formed near the second dripping portion 74b. Therefore, the plurality of openings 76b are arranged along the longitudinal direction of the second heat transfer pipe 6b.

[0049] The tray 71b, the holder 73b, and the slit member 77b can each be manufactured by, for example, press-working a stainless steel plate. The second dripper 7b can be manufactured by welding the tray 71b, the holder 73b, and the slit member 77b.

[0050] The interior space of the first container 5a and the interior space of the second container 5b are connected by the vapor flow path 4. A separator 12 is disposed in the vapor flow path 4. The vapor flow path 4 includes a portion curved by the separator 12. This prevents the refrigerant liquid in the first container 5a from being dragged into the interior of the second container 5b by the flow of the refrigerant vapor.

[0051] The steam flow path 4 is made of a metal material such as iron having heat-insulating and pressure-resistant properties. The separator 12 is produced by welding parts formed by pressing stainless steel plates.

[0052] As the refrigerant filling the heat exchange unit 1, for example, hydrofluorocarbon (HFC)-based Freon-based refrigerant or natural refrigerant such as water and ammonia is used. In addition, as the solution filling the heat exchange unit 1, for example, lithium bromide aqueous solution and ionic fluid are used.

[0053] like Figure 1 As shown, the heat exchange unit 1 further includes, for example, a first pump 8 , a circulation path 9 , a first supply path 13 , a second supply path 14 , a discharge path 15 , and a second pump 16 .

[0054] The first pump 8 is, for example, a canned pump. The first pump 8 is disposed in a circulation path 9. One end of the circulation path 9 is connected to the first container 5a. The operation of the first pump 8 pressurizes the refrigerant liquid stored in the first container 5a through the circulation path 9.

[0055] The first supply path 13 is connected to the first container 5a. The refrigerant liquid is supplied to the first container 5a through the first supply path 13. The refrigerant liquid supplied to the first container 5a is directed to the first dripper 7a. The other end of the circulation path 9 is connected to the first circulation path 13, and the refrigerant liquid that has passed through the circulation path 9 is supplied to the first container 5a again.

[0056] The second supply path 14 is connected to the second container 5b. The solution is supplied to the second container 5b through the second supply path 14. The solution supplied to the second container 5b is guided to the second dropper 7b.

[0057] The discharge path 15 is connected to the second container 5 b. A second pump 16 is disposed in the discharge path 15. The second pump 16 is, for example, a speed-type canned motor pump. The operation of the second pump 16 pumps the solution stored in the second container 5 b to the outside of the absorber 3 under pressure.

[0058] The circulation path 9 , the first supply path 13 , the second supply path 14 , and the discharge path 15 are each formed of a flow path member having heat insulating properties and pressure resistance, for example.

[0059] [1-2. Action]

[0060] The operation and function of the heat exchange unit 1 constructed as described above will be described below. When the heat exchange unit 1 is left at a specific time, such as at night, the temperature inside the heat exchange unit 1 is approximately equal to and uniform to the room temperature, and the pressure inside the heat exchange unit 1 also becomes uniform. For example, when the room temperature is 25°C, the interior of the heat exchange unit 1 also becomes uniform at 25°C. When the heat exchange unit 1 is in use, a heat medium such as water that has absorbed heat from the outside of the heat exchange unit 1 flows inside the first heat conduction tube 6a of the first heat conduction tube group 6f. This heat medium flows into the first heat conduction tube 6a at, for example, 12°C. On the other hand, a heat medium such as water that has dissipated heat to the outside of the heat exchange unit 1 flows inside the second heat conduction tube 6b of the second heat conduction tube group 6s. This heat medium flows into the second heat conduction tube 6b at, for example, 32°C.

[0061] When the heat exchange unit 1 is started to be used, the refrigerant liquid is first supplied to the interior of the evaporator 2 through the first supply path 13. The temperature of the supplied refrigerant liquid is, for example, about 35°C. Figure 2A as well as Figure 2B As shown, the refrigerant liquid 18 supplied to the evaporator 2 is stored in the storage space 70a of the tray 71a of the first dripper 7a. The refrigerant liquid 18 stored in the storage space 70a is distributed by the distribution holes 72a and the opening 76a and drips from the first dripping portion 74a toward the first heat transfer tube group 6f. The dripped refrigerant liquid 18 forms droplets 24, flows down the outer surface of the first heat transfer tube 6a, and is stored in the lower portion of the first container 5a. The refrigerant liquid 18 stored in the lower portion of the first container 5a is pumped by the pump 8 through the circulation path 9 and directed back into the evaporator 2. In this way, the refrigerant liquid 18 circulates inside and outside the evaporator 2. When the absorption chiller equipped with the heat exchange unit 1 is operating at rated load, the flow rate of the refrigerant liquid 18 is, for example, approximately 30 liters / minute. The amount of refrigerant liquid 18 dripping from the first dripper 7a is also roughly equal to this flow rate.

[0062] Next, solution 26 is supplied to absorber 3 through second supply path 14. The temperature, solute concentration, and viscosity of the supplied solution 26 are, for example, 50°C, 63% by mass, and approximately 0.00678 Pa·s, respectively. The viscosity of solution 26 can be approximately 4.8 times the viscosity of the refrigerant liquid supplied to evaporator 2. Solution 26 supplied to absorber 3 is stored in storage space 70b within tray 71b of second dripper 7b. Solution 26 stored in storage space 70b is distributed by distribution holes 72b and opening 76b and drips from second dripping portion 74b toward second heat transfer tube group 6s. The dripped solution 26 forms droplets 27, flows down the outer surface of second heat transfer tube 6b, and is stored in the lower portion of second container 5b. Solution 26 stored in the lower portion of second container 5b is pumped by second pump 16 and discharged to the exterior of heat exchange unit 1 through discharge path 15. When the absorption chiller equipped with the heat exchange unit 1 is operated at rated load, the flow rate of the solution 26 supplied from the second supply path 14 and dripped by the second dripper 7b is, for example, approximately 16 liters / minute. This flow rate is approximately half the flow rate of the refrigerant liquid 18 when the absorption chiller is operated at rated load.

[0063] As solution 26 flows down the outer surface of second heat transfer tube 6b, the refrigerant vapor filling heat exchange unit 1 is absorbed by solution 26. This causes the temperature of solution 26 to rise. Simultaneously, the heat medium flowing inside second heat transfer tube 6b cools solution 26, so absorption by the supercooled solution 26 continues. Consequently, the pressure inside the heat exchange unit decreases. Simultaneously, refrigerant liquid 18 flowing down the outer surface of first heat transfer tube 6a evaporates. This evaporation lowers the temperature of refrigerant liquid 18. However, at the same time, the heat medium flowing inside first heat transfer tube 6a superheats refrigerant liquid 18, causing it to evaporate continuously. This maintains the pressure inside heat exchange unit 1 within a predetermined range, achieving a stable state. The temperature and viscosity of refrigerant liquid 18 in this stable state are approximately 7°C and 0.001427 Pa·s, respectively. On the other hand, the temperature, solute concentration, and viscosity of the solution 26 discharged from the absorber 3 are approximately 36° C., 57% by mass, and 0.004768 Pa·s, respectively.

[0064] use Figure 2A 、 Figure 2B 、 Figure 3A 、 Figure 3B as well as Figure 4 The operations of the first dripper 7a and the second dripper 7b will be described.

[0065] like Figure 2A as well as Figure 2BAs shown, the refrigerant liquid 18 supplied to the first dripper 7a through the first supply path 13 is stored in the storage space 70a. The refrigerant liquid 18 stored in the storage space 70a is distributed from the multiple distribution holes 72a arranged along the length of the tray 71a while flowing down. The refrigerant liquid 18 is guided toward the inclined surface of the retaining member 73a and flows down the surface of the retaining member 73a. Next, the refrigerant liquid 18 is guided toward the groove 78a and stored again. Thereafter, the refrigerant liquid 18 is distributed again and flows down through the multiple openings 76a arranged along the length of the tray 71a. The refrigerant liquid 18 that has passed through the openings 76a is guided toward the first dripping portion 74a and drips from the first front end portion 75a of the first dripping portion 74a. The refrigerant liquid 18 dripped from the first dripping portion 74a forms droplets 24, then spreads on the surface of the first heat transfer pipe 6a and flows down while forming a liquid film 25.

[0066] like Figure 3A as well as Figure 3B As shown, the solution 26 supplied to the second dripper 7b through the second supply path 14 is stored in the storage space 70b. The solution 26 stored in the storage space 70b is distributed from the multiple distribution holes 72b arranged along the length direction of the tray 71b while flowing down. The solution 26 is guided toward the inclined surface of the retaining member 73b and flows down the surface of the retaining member 73b. Next, the solution 26 is guided toward the groove 78b and stored again. Thereafter, the solution 26 is distributed again and flows down through the multiple openings 76b arranged along the length direction of the tray 71b. The solution 26 that has passed through the openings 76b is guided toward the second dripping portion 74b and drips from the second front end portion 75b of the second dripping portion 74b. The solution 26 dripped from the second dripping portion 74b forms droplets 27, then spreads on the surface of the second heat transfer pipe 6b and flows down while forming a liquid film 28.

[0067] Figure 4 1 and 2 schematically show a state in which a solution 26 is dripped using a dripper 7p of a reference example instead of the second dripper 7b. The dripper 7p has the same configuration as the first dripper 7a.

[0068] [1-3. Effects, etc.]

[0069] As described above, in this embodiment, the absorption chiller heat exchange unit 1 includes a first container 5a, a first heat transfer tube group 6f, a first dripper 7a, a second container 5b, a second heat transfer tube group 6s, and a second dripper 7b. The first heat transfer tube group 6f includes a plurality of first heat transfer tubes 6a arranged in multiple layers and rows within the first container 5a. The first dripper 7a has a plurality of first dripping portions 74a arranged along the length of the first heat transfer tubes 6a. The first dripper 7a drips the refrigerant liquid from the first dripping portions 74a toward the first heat transfer tube group 6f. The second heat transfer tube group 6s includes a plurality of second heat transfer tubes 6b arranged in multiple layers and rows within the second container 5b. The second dripper 7b has a plurality of second dripping portions 74b arranged along the length of the second heat transfer tubes 6b. The second dripper 7b drips the solution from the second dripping portions 74b toward the second heat transfer tube group 6s. A distance P2 between adjacent second dripping portions 74b in the longitudinal direction (X-axis direction) of the second heat transfer tube 6b is smaller than a distance P1 between adjacent first dripping portions 74a in the longitudinal direction of the first heat transfer tube 6a.

[0070] like Figure 2A as well as Figure 2B As shown, the viscosity of the refrigerant liquid 18 dripping from the first dripper 7a is low, and the flow rate of the refrigerant liquid 18 is also large. Therefore, even when the interval P1 is relatively large, the wettability of the refrigerant liquid 18 in the first heat transfer pipe 6a is easily improved. Figure 4 As shown, when the solution 26 is dripped using a dripper 7p having the same structure as the first dripper 7a, the liquid film 28 formed on the surface of the second heat conducting tube 6b is difficult to spread. This is because the viscosity of the solution 26 is approximately 4.8 times higher than that of the refrigerant liquid 18. Therefore, when the dripper 7p is used, the area of ​​the surface of the second heat conducting tube 6b not wetted by the solution 26 increases, making it difficult to achieve good wettability of the solution 26 in the second heat conducting tube 6b. On the other hand, according to this embodiment, the spacing P2 is smaller than the spacing P1, so when the solution 26 is dripped by the second dripper 7b, the spacing between the droplets 27 is reduced. As a result, the liquid film 28 is uniformly formed on the surface of the second heat conducting tube 6b, and the wettability of the solution 26 in the second heat conducting tube 6b is easily improved.

[0071] According to this embodiment, a heat exchange method including the following matters (I), (II), and (III) can be provided.

[0072] (I) A first heat medium is supplied into the interior of a first heat transfer tube group 6f, which includes a plurality of first heat transfer tubes 6a arranged in multiple layers and rows within a first container 5a. Furthermore, a refrigerant liquid 18 is dripped into the first heat transfer tube group 6f from a plurality of locations arranged at first intervals P1 along the longitudinal direction of the first heat transfer tubes 6a.

[0073] (II) The second heat medium is supplied into the interior of the second heat transfer tubes 6b in the second heat transfer tube group 6s, which includes a plurality of second heat transfer tubes 6b arranged in multiple layers and rows within the second container 5b. Furthermore, the solution 26 is dripped into the second heat transfer tube group 6s from a plurality of locations arranged at second intervals P2 along the longitudinal direction of the second heat transfer tubes 6b.

[0074] (III) The first interval P2 is smaller than the first interval P1.

[0075] (Implementation Method 2)

[0076] Below, use Figure 5A as well as Figure 5B The second embodiment will be described. The heat exchange unit of the second embodiment is configured similarly to the heat exchange unit 1 of the first embodiment except for the parts specifically described. Figure 5A The second dripper 7c of the second embodiment shown is constructed identically to the second dripper 7b, except for portions specifically described. Components of the second dripper 7c that are identical to or correspond to those of the second dripper 7b are denoted by the same reference numerals, and detailed descriptions thereof are omitted. The descriptions regarding the first embodiment are fully applicable to the second embodiment, provided there are no technical inconsistencies.

[0077] [2-1. Structure]

[0078] like Figure 5A As shown, in the second dripper 7c, the second dripper portion 74a has a second tip 75b that tapers toward the second heat transfer tube group 6s. The second tip 75b is more pointed than the first tip 75a. In other words, the width of the second projection at a specific distance from the tip of the second projection is smaller than the width of the first projection at a specific distance from the tip of the first projection. The second projection is obtained by projecting the second tip 75b onto a plane parallel to the longitudinal direction of the second heat transfer tube 6b in a direction perpendicular to the longitudinal direction of the second heat transfer tube 6b. The first projection is obtained by projecting the first tip 75a onto a plane parallel to the longitudinal direction of the first heat transfer tube 6a in a direction perpendicular to the longitudinal direction of the first heat transfer tube 6a.

[0079] [2-2. Action]

[0080] The following describes the operation and function of the second dripper 7c configured as described above. When an absorption chiller equipped with a heat exchange unit 1 is operating at a load of approximately 50%, the amount of refrigerant vapor generated by the evaporator 2 and absorbed by the absorber 3 is approximately half. Meanwhile, the circulation rate of the refrigerant liquid 18 dripped from the first dripper 7a toward the first heat transfer tube group 6f remains constant, for example, at approximately 30 liters / minute, regardless of the load of the absorption chiller. This is because the refrigerant liquid 18 stored in the first container 5a circulates through the circulation path 9 within and outside the evaporator 2 under the action of the first pump 8. Meanwhile, the flow rate of the solution 26 dripped from the second dripper 7c is determined by the load of the absorption chiller. Therefore, when the absorption chiller is operating at a load of approximately 50%, the flow rate of the solution 26 dripped from the second dripper 7c is, for example, approximately 8 liters / minute, which is approximately one-quarter of the flow rate of the refrigerant liquid 18.

[0081] like Figure 5A as well as Figure 5B As shown, the solution 26 supplied via the second supply path 14 is stored in the storage space 70b. The solution 26 stored in the storage space 70b is distributed from the multiple distribution holes 72b arranged along the longitudinal direction of the tray 71b while flowing down. The solution 26 is guided to the inclined surface of the retaining member 73b and flows down on the surface of the retaining member 73b. Next, the solution 26 is guided to the groove 78b and stored again. Thereafter, the solution 26 is distributed again and flows down through the multiple openings 76b arranged along the longitudinal direction of the tray 71b. The solution 26 that has passed through the openings 76b is guided to the second dripping portion 74b and drips from the second front end portion 75b of the second dripping portion 74b. At this time, the solution 26 flows down and drips, for example, in a state inscribed in the second projection of the second front end portion 75b. Figure 5A as well as Figure 5B The states of the liquid film 28 of the solution 26 at time t and time t+Δt are shown respectively.

[0082] [2-3. Effects, etc.]

[0083] As described above, in this embodiment, the second front end portion 75b is sharper than the first front end portion 75a. For example, when the absorption refrigeration machine equipped with the heat exchange unit of this embodiment is operated at a load of about 50%, the flow rate of the solution 26 dripped by the second dripper 7c is greatly reduced. This flow rate can be, for example, 1 / 4 of the flow rate of the refrigerant liquid 18 dripped by the first dripper 7a, and can be half of the flow rate of the solution 26 dripped by the second dripper 7c during the rated operation of the absorption refrigeration machine. For example, Figure 6A as well as Figure 6BAs shown, consider the case where the dripper 7p of the reference example is used instead of the second dripper 7c. In this case, even if the liquid film 28 extends over a wide area on the surface of the second heat transfer tube 6b at time t, the area of ​​the second heat transfer tube 6b covered by the liquid film 28 at time t+Δt is reduced. Consequently, the wetting state of the solution 26 on the surface of the second heat transfer tube 6b may become uneven over time. This is because the diameter of the droplets 27 of the solution 26 is approximately the same as, and larger than, the diameter of the droplets 24 of the refrigerant liquid 18.

[0084] On the other hand, in this embodiment, the second tip 75b is more pointed than the first tip 75a, and the solution 26 drips down along this more pointed second tip 75b. Consequently, the diameter of the solution 26 droplets 27 is reduced. When the flow rates of solution 26 in the second dripper 7c and the dripper 7p are equal, the time interval between drops of solution 26 in the second dripper 7c is shortened. In other words, the solution 26 drips continuously toward the second heat transfer tube group 6s in a temporally uniform manner. Therefore, even when an absorption chiller equipped with the heat exchange unit of this embodiment is operated at a load approximately 50% lower than the flow rate of solution 26, temporal nonuniformity in the wetting state of the solution 26 on the surface of the second heat transfer tube 6b is suppressed. Consequently, a good liquid film 28 can be formed on the surface of the second heat transfer tube 6b.

[0085] (Implementation 3)

[0086] Below, use Figure 7 Implementation method 3 will be described.

[0087] [3-1. Structure]

[0088] like Figure 7 As shown, the absorption refrigerator 100 includes a heat exchange unit 1. The absorption refrigerator 100 further includes, for example, a regenerator 80 and a condenser 90. The absorption refrigerator 100 is, for example, a single-effect cycle absorption refrigerator.

[0089] [3-2. Action]

[0090] The operation and function of the absorption refrigeration machine 100 constructed as described above will be described below. The solution 26 stored in the second container 5b is guided to the regenerator 80 through the discharge path 15. The solute concentration of the solution 26 is increased by heating in the regenerator 80. The solution 26 with increased solute concentration is guided to the absorber 3 through the second supply path 14. On the other hand, refrigerant vapor is generated by heating the solution 26 in the regenerator 80. The refrigerant vapor is guided to the condenser 90, where it is cooled and condensed to generate a refrigerant liquid. After being decompressed, the refrigerant liquid is guided to the evaporator 2 through the first supply path 13, for example.

[0091] [3-3. Effect]

[0092] As described above, in this embodiment, absorption chiller 100 includes heat exchange unit 1. In heat exchange unit 1, liquid film 28 of solution 26 is uniformly formed on the surface of second heat transfer tube 6b, and the wettability of solution 26 in second heat transfer tube 6b is easily improved. Consequently, the coefficient of performance (COP) of absorption chiller 100 is easily improved.

[0093] (Other embodiments)

[0094] As described above, embodiments 1, 2, and 3 have been described as examples of the technology disclosed in this application. However, the technology of the present invention is not limited to these embodiments and can also be applied to embodiments that have been modified, replaced, added, or omitted. In addition, the components described in embodiments 1 and 2 can be combined to form new embodiments. Therefore, other embodiments are described below.

[0095] In Embodiment 1, a configuration comprising a tray 71a, a holder 73a, and a slit member 77a is described as an example of a first dripper 7a. The first dripper 7a can simply drip the refrigerant liquid from a plurality of first dripping portions 74a toward the first heat transfer tube group 6f. Therefore, the first dripper 7a is not limited to a configuration comprising a tray 71a, a holder 73a, and a slit member 77a. However, such a configuration of the first dripper 7a facilitates distribution of the refrigerant liquid along the length of the first heat transfer tube 6a.

[0096] In Embodiments 1 and 2, as examples of the second drippers 7b and 7c, a configuration comprising a tray 71b, a holder 73b, and a slit member 77b is described. The second drippers 7b and 7c only need to drip the solution from a plurality of second dripping portions 74b toward the second heat transfer tube group 6s. Therefore, the second drippers 7b and 7c are not limited to configurations comprising a tray 71b, a holder 73a, and a slit member 77a. However, such configurations of the second drippers 7b and 7c facilitate distribution of the solution along the length of the second heat transfer tubes 6b.

[0097] In Embodiments 1 and 2, the first dripping portion 74a is described as having a first, tapered tip 75a that projects toward the first heat transfer tube group 6f, and the second dripping portion 74b is described as having a second, tapered tip 75b that projects toward the second heat transfer tube group 6s. The first dripping portion 74a and the second dripping portion 74b only need to be capable of dripping refrigerant liquid and solution, respectively. Therefore, the first dripping portion 74a and the second dripping portion 74b may not have the tapered first and second tip 75a, respectively. However, if the first dripping portion 74a has the tapered first tip 75a, it is easier to adjust the diameter of the refrigerant liquid droplets dripping from the first dripping portion 74a to a desired size. Furthermore, if the second dripping portion 74b has the tapered second tip 75b, it is easier to adjust the diameter of the solution droplets dripping from the second dripping portion 74b to a desired size.

[0098] In embodiments 1 and 2, the first dripping portion 74a and the second dripping portion 74b are each plate-shaped. The first dripping portion 74a and the second dripping portion 74b can drip the refrigerant liquid and the solution, respectively. Therefore, the first dripping portion 74a and the second dripping portion 74b are not limited to being plate-shaped. However, if the first dripping portion 74a and the second dripping portion 74b are plate-shaped, it is easy to manufacture the first dripping portion 74a and the second dripping portion 74b. The first dripping portion 74a and the second dripping portion 74b can be tapered or have a hollow structure.

[0099] In Embodiment 3, a single-effect cycle absorption chiller is described as an example of an absorption chiller 100. The absorption chiller 100 only needs to include the heat exchange unit 1. Therefore, the absorption chiller 100 is not limited to a single-effect cycle absorption chiller. The absorption chiller 100 may also be a double-effect cycle or triple-effect cycle absorption chiller. When a gas burner is used as the heat source for the regenerator 80, the absorption chiller 100 can be a gas-type chiller.

[0100] It should be noted that the above-mentioned embodiments are provided to illustrate the technology in the present invention, and therefore various changes, substitutions, additions, and omissions can be made within the scope of the technical claims or the scope of their equivalents.

[0101] Industrial Applicability

[0102] The present invention can be applied to absorption refrigeration machines suitable for central air conditioners in buildings and refrigeration machines for process cooling.

Claims

1. A heat exchange unit for an absorption refrigeration machine, wherein: The absorption refrigeration machine heat exchange unit comprises: a first container; a first heat-conducting pipe group including a plurality of first heat-conducting pipes arranged in multiple layers and multiple rows inside the first container; a first dripper having a plurality of first dripping parts arranged along the length direction of the first heat transfer tube and dripping the refrigerant liquid from the first dripping parts toward the first heat transfer tube group; a second container; a second heat-conducting pipe group comprising a plurality of second heat-conducting pipes arranged in multiple layers and multiple rows inside the second container; as well as The second dripper has a plurality of second dripping parts arranged along the length direction of the second heat transfer tube, and drips the solution from the second dripping parts toward the second heat transfer tube group. The interval between the second dripping portions adjacent to each other in the longitudinal direction of the second heat transfer tube is smaller than the interval between the first dripping portions adjacent to each other in the longitudinal direction of the first heat transfer tube.

2. The heat exchange unit for an absorption refrigeration machine according to claim 1, wherein: The first dripping portion has a first front end portion that protrudes toward the first heat conduction pipe group and tapers. The second dripping portion has a second front end portion that protrudes toward the second heat conduction pipe group and becomes thinner. The second front end portion is sharper than the first front end portion.

3. An absorption refrigeration machine, wherein: The absorption refrigerator includes the heat exchange unit for an absorption refrigerator according to claim 1 or 2.

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