JP2002277089A - Absorption refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce in size a two-stage absorption refrigerator (1) by decreasing sizes of an evaporator (5) and an absorber (6) of the apparatus (1). SOLUTION: The absorption refrigerator comprises a plate type heat exchanger (30) having the evaporator (5) and the absorber (6) in which a plurality of hollow panels (32) are arrayed at a predetermined interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigeration system, and more particularly to an absorption refrigeration system in which an absorber and an evaporator are arranged in two stages on a low pressure side and a high pressure side, respectively, to perform a two-stage absorption refrigeration cycle. It is related to.

[0002]

2. Description of the Related Art Generally, an absorption refrigerating apparatus is provided with a generator, a condenser, an evaporator, an absorber, and a heat exchanger, for example, as disclosed in JP-A-2000-74521. Some absorption refrigeration systems use water as a refrigerant and a lithium bromide aqueous solution as an absorption medium to cool water and the like in a utilization side circuit while circulating them.

[0003] For example, as shown in FIG.
In (1), the generator (2,3), condenser (4), evaporator (5)
, Absorber (6), and heat exchanger (7, 8) are connected in this order so as to form a closed circuit, while cooling water pipe (9) is connected from absorber (6) to condenser (4). ) Is connected and the evaporator (5)
Is provided with a water pipe (10) of a utilization side circuit through which cooling water for cooling or the like flows. From the generator (2,3) to the absorber (6),
Solution piping for supplying high-concentration lithium bromide aqueous solution
(18) is connected.

In this absorption refrigeration system (1), a generator (2,
The dilute aqueous solution of lithium bromide is heated in step 3) to generate steam, which is then cooled by cooling water in a condenser (4) to condense. The condensed water is evaporated by the heat of the water in the use side circuit in the low-pressure evaporator (5), and the liquid to be cooled such as cooling water for cooling is cooled. The water vapor generated at this time is absorbed by the absorber (6).
It is led to. In the absorber (6), the concentrated lithium bromide aqueous solution concentrated in the generators (2, 3) is cooled with cooling water while absorbing steam, and the lithium bromide aqueous solution is again made into a dilute aqueous solution. The dilute aqueous lithium bromide solution thus generated is sent to the generators (2, 3) by a pump (not shown) and reheated. At this time, the concentrated lithium bromide aqueous solution flowing down from the generator (2,3) and the dilute aqueous solution of lithium bromide at room temperature exchange heat with the heat exchangers (7,8) to achieve high concentration. The solution is cooled and the low concentration solution is heated. By circulating the aqueous lithium bromide solution as described above, the water in the use side circuit is cooled.

[0005] In the conventional absorption refrigeration system (1), a shell-and-tube type heat exchanger is generally used for the evaporator (5) and the absorber (6). The shell-and-tube heat exchanger is a heat exchanger in which a number of cooling tubes (tubes) are arranged in a steel plate cylinder (shell) placed horizontally, for example. Then, condensed water or an absorbing medium solution is supplied into the shell, and water or the like is supplied into the tube.

[0006]

By the way, conventionally,
In an absorption refrigeration system, a two-stage absorption refrigeration cycle may be used for the purpose of adjusting the concentration difference of the absorption solution between the inlet side and the outlet side of the absorber to increase the COP (coefficient of performance). . In the two-stage absorption refrigeration cycle, two evaporators and two absorbers are divided into two stages, a low-pressure side and a high-pressure side, and are arranged at the top and bottom to constitute a low-pressure body. The process is performed in two stages.

However, when a two-stage absorption refrigeration system is constructed using an evaporator and an absorber constituted by a shell-and-tube heat exchanger, if the evaporator and the absorber are arranged vertically, the same capacity can be obtained in a single stage. The total volume of the evaporator and the absorber is considerably larger than that of the absorption refrigeration system of No.
There is a problem that the size is increased about five times.

The present invention has been made in view of the above problems, and has as its object to reduce the size of an evaporator and an absorber of a two-stage absorption refrigeration system to reduce the size of the system. It is to plan.

[0009]

According to the present invention, a plate-type heat exchanger (30) is used for the evaporator (5) and the absorber (6) of the two-stage absorption refrigeration system (1). is there.

More specifically, the solution taken by the present invention is based on the premise that an evaporator (5) and an absorber (6) are provided in two stages, respectively, to perform an absorption refrigeration cycle with two stages. I have. The absorption refrigeration system (1) is
(5) and absorber (6) are each a plate heat exchanger (3
0). The plate heat exchanger (30) is constituted by a heat exchanger unit (31). This heat exchanger unit (31) has a plurality of hollow panels.
(32) are arranged at predetermined intervals and integrated, and the entrance passages (36, 36, ...) communicating with the internal space of each panel (32)
And an outlet passage (37, 37, ...), and furthermore, a protection plate (35) for protecting the panel (32) is provided outside the panels (32) at both ends connected by brazing or welding. I have.

Further, in the above configuration, the plate heat exchanger (30) may have a configuration in which a plurality of heat exchanger units (31) are connected.

Further, in the above configuration, the plate heat exchanger (30) may have a configuration in which a plurality of heat exchanger units (31) are connected in series.

In the above configuration, the plate-type heat exchanger (30) includes a plurality of heat exchanger units (31) which are connected between the heat exchanger units (31) through connecting pipes (43, 44). Connected.

Further, in the above configuration, the plate heat exchanger (30) may have a configuration in which the protection plates (35) of the plurality of heat exchanger units (31) are directly connected to each other.

-Operation- The operation of the refrigeration system of the two-stage absorption refrigeration cycle, for example, as shown in FIG. 1, will be described. This refrigeration system (1) is a double effect absorption refrigeration system that performs a two-stage absorption refrigeration cycle, and includes a high-temperature generator (2), a low-temperature generator (3), and a condenser (4). , Evaporator (5), absorber (6), low-temperature heat exchanger (7) and high-temperature heat exchanger (8) constitute a closed circuit, in which water (refrigerant) and lithium bromide (absorption medium) It is configured to circulate inside. The device (1) includes a solution pipe (18) through which a high-concentration aqueous solution of the absorbing medium is supplied from the low-temperature generator (3) to the absorber (6) via the low-temperature heat exchanger (7). The evaporator (5) was provided with a chilled water pipe (10) for the use side circuit, and the absorber (6) was provided with a chilled water pipe (9) for flowing cooling water etc. from the condenser (4). It has a configuration.

In this configuration, first, water vapor generated by heating an aqueous solution of an absorbing medium such as lithium bromide in the high-temperature generator (2) and an aqueous solution of intermediate concentration concentrated at that time are mixed with the low-temperature generator ( And the intermediate concentration solution is heated in the low temperature generator (3). The steam generated by heating in the low-temperature generator (3) is supplied to the condenser (4), where it exchanges heat with cooling water and liquefies. In the steam generated from the high-temperature generator (2), the liquefied refrigerant is simultaneously supplied to the condenser (4) via the low-temperature generator (3). The condensed water flows into the low-pressure evaporator (5) and exchanges heat with a liquid to be cooled such as cooling water for cooling, and cools and evaporates the cold water. The vapor generated at this time is introduced into the absorber (6) and is absorbed by the concentrated aqueous solution of the absorbing medium concentrated in the low-temperature generator (3), and the solution becomes a dilute aqueous solution. Then, the diluted aqueous solution of the absorbing medium is passed through the low-temperature heat exchanger (7) and the high-temperature heat exchanger (8),
(2) to complete one cycle.

As described in the above cycle, the absorption medium and water are circulated in the circuit while the absorption medium solution is heated by the high-temperature generator (2), so that the water or the like in the utilization side circuit (10) is covered. The cooling liquid is cooled, and the cold heat can be used for cooling or the like.

In the above solution, the evaporator (5) and the absorber (6) are arranged in two stages on the low pressure side and the high pressure side, respectively, so that the evaporation process and the absorption process are performed in two stages. hand,
It becomes a two-stage absorption refrigeration cycle. In the two-stage absorption refrigeration cycle, the evaporator (5) and the absorber (6) are set at a slightly higher pressure on the lower side than the upper side in FIG. After being absorbed by the high-concentration solution of the absorption medium in the side absorber (16), the vapor obtained by evaporating the condensed water in the high-pressure side evaporator (15) is further reduced in the high-pressure side absorber (17) by the low-pressure side absorber (16). To a low concentration solution.

In the above configuration, the evaporator (5) and the absorber (6) are constituted by the plate-type heat exchanger (30) in which hollow panels (32) are arranged at predetermined intervals and integrated. Therefore, in the evaporator (5), the liquid to be cooled such as cold water flowing in each panel (32) and the liquid generated in the condenser (6)
The heat exchanges with the condensed water supplied to the outer space of the panel, while the absorber (6) absorbs the water that is concentrated by the low-temperature generator (3) and supplied to the outer space of each panel (32). The aqueous solution of the medium exchanges heat with the cooling water flowing through each panel (32).

[0020]

According to the above solution, since the evaporator (5) and the absorber (6) are constituted by the plate type heat exchanger (30), the evaporator (5) and the absorber (6) The size of the apparatus can be reduced as compared with a conventional two-stage absorption refrigeration apparatus using a shell-and-tube heat exchanger. In particular, evaporators
Both the low pressure side and the high pressure side of the (5) and the absorber (6) are plate heat exchangers (30), so if they are arranged vertically, they are all shell and tube heat exchangers. Compared to using a heat exchanger, the effect of reducing the size of each heat exchanger is superimposed, so that the overall size can be significantly reduced. Also, when assembling a shell-and-tube heat exchanger, it is necessary to expand the settle, and the number of heat transfer tubes increases with the increase in refrigeration capacity. And an inexpensive refrigerator can be provided.

When the heat exchanger unit (31) constituting the plate type heat exchanger (30) has a structure in which a plurality of hollow panels (32) are arranged at predetermined intervals, each panel (32) The thickness of the heat transfer surface is inevitably thin in view of its function, but since the protection plates (35) are provided on the panels (32) on both sides of the heat transfer surfaces, heat exchange is performed by the protection plates (35). Unit
Each panel (32) can be protected while securing the strength of (31).
For this reason, it is difficult to put it to practical use simply by arranging the hollow panels (32) at predetermined intervals.However, according to the above configuration, the plate-type heat exchanger (30) used in the absorption refrigeration system (1) is used. It can be practically used.

When the plate-type heat exchanger (30) has a structure in which a plurality of heat exchanger units (31) are connected, the number of panels (32) of each heat exchanger unit (31) is relatively small. However, by connecting the heat exchanger units (31) to each other, a plate-type heat exchanger (30) having a required size and a required capacity can be easily configured.

Further, the plate type heat exchanger (30) may have a configuration in which a plurality of heat exchanger units (31) are arranged in series, or each heat exchanger unit (31) may be connected to a connecting pipe (43, 44). ), The heat exchanger units (31) can be easily connected to each other.

Further, when the protection plates (35) of the plurality of heat exchanger units (31) are directly connected to each other, the plate type heat exchanger (30) can be further downsized, so that the apparatus can be further downsized. It becomes possible.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings.

-Circuit Configuration- FIG. 1 is a circuit diagram of the absorption refrigeration system (1) of the present embodiment. In this absorption refrigeration system (1), water is used as a refrigerant,
The liquid to be cooled such as water in the utilization side circuit is cooled by using lithium bromide as an absorption medium and used for cooling or the like.
Further, the absorption refrigeration system (1) of the present embodiment is such that a two-stage absorption refrigeration cycle is performed by a double effect absorption refrigeration system.

As shown in FIG. 1, the absorption refrigeration system
(1) High-temperature generator for concentrating aqueous lithium bromide (2)
And a low-temperature generator (3), a condenser (4) in which steam generated in the low-temperature generator (3) condenses, water condensed in the condenser (4) and steam generated from the high-temperature generator (2). Evaporator (5) where the liquefied water evaporates via the low-temperature generator (3), and the evaporator (5)
An absorber (6) that absorbs the water vapor generated in the process into an aqueous solution of lithium bromide, a low-temperature heat exchanger (7) that exchanges heat between a high-concentration solution and a low-concentration solution of lithium bromide, and an intermediate concentration of lithium bromide. A high-temperature heat exchanger (8) for exchanging heat between the solution and the low-concentration solution is connected to a pipe to form a closed circuit. Although not shown, a pump for circulating the solution is provided between the absorber (6) and the high-temperature generator (2).

The absorber (6) and the condenser (4) are provided with a cooling water pipe (9) through which cooling water flows, and the evaporator (5) is provided with a cooling water pipe (10) of a use side circuit. Have been. Cooling water piping
In (9), the lower part of the absorber (6) is formed on the inlet side, and communicates from the upper part of the absorber (6) to the lower part of the condenser (4), and the upper part of the condenser (4) is the outlet side. Is configured. In the chilled water pipe (10), the lower part of the evaporator (5) is formed on the inlet side, and the upper part of the evaporator (5) is formed on the outlet side.

The high-temperature generator (2) includes a gas burner (11).
Are provided, and the lithium bromide aqueous solution is heated by the combustion gas.

The low-temperature generator (3) and the condenser (4) are arranged in a single body (not shown) to form an upper body (12). On the other hand, the evaporator (5) and the absorber (6) are arranged in one body (20) (see FIGS. 2 and 3),
(13) is constituted. This low-pressure body (13) is
It is located below 2).

-Low-Pressure Body- The evaporator (5) and the absorber (6) of the low-pressure body (13) are respectively arranged vertically in two parts. The evaporator (5)
A low-pressure side evaporator (1) whose evaporation pressure is set to a predetermined low pressure
4) and a high-pressure side evaporator (15) slightly higher in pressure. Similarly to the evaporator (5), the absorber (6) is composed of a low-pressure side absorber (16) of a predetermined low pressure and a high-pressure side absorber (17) of a slightly higher pressure. I have.

As described above, the evaporator (1) is provided in the low-pressure body (13).
4,15) and absorbers (16,17) are arranged one above the other,
The evaporating process and the absorbing process are configured to be performed in two stages of a low pressure side and a high pressure side. The low-pressure body (13) is, specifically,
As shown in FIGS. 2 and 3, the shell (21) and the end plate
The inside of the body (20) consisting of (22) and the stand (23) is divided into upper and lower parts, and the evaporators (14, 15) and the absorbers (16, 17) are placed on the upper low pressure side and the lower high pressure side, respectively. Are located. Evaporators (14, 15) and absorbers (16, 17)
An eliminator (24) is provided between them to separate water droplets and water vapor and supply the water vapor to the absorbers (16, 17).

-Plate type heat exchanger- The evaporator (14, 15) and the absorber (16, 17) are each constituted by a plate type heat exchanger (30) configured similarly to each other. As shown in FIG. 4, the plate heat exchanger (30) is configured by connecting a plurality (two in the figure) of heat exchanger units (31) in series by welding or brazing.

Each heat exchanger unit (31) has a structure in which a plurality of hollow panels (32) are arranged at predetermined intervals and integrated. Each panel (32) is formed by joining two thin heat transfer plates (33) formed by press working to each other at a peripheral edge (34) by brazing. Further, a protection plate (35) is joined to each heat exchanger unit (31) by brazing outside the panels (32, 32) at both ends.

The inner shape of the two heat transfer plates (33) constituting each panel (32) is shown in FIG. 5, the outer shape is shown in FIG.
FIG. 7 shows the appearance of the protection plate (35). Each of the heat transfer plates (33) is formed in a shallow box shape with one surface opened, and the peripheral portions (34) are overlapped to join the two heat transfer plates (33). That is, the peripheral portion (34) forms a joint.

Each of the heat transfer plates (33) has a joint (34)
Water inlet opening (36) and outlet opening (3
7) are arranged vertically. And this entrance opening (36)
A concave fitting part (38) is formed between the outlet opening (37) and the joint part (34b) on the side opposite to the joint part (34a) on which these openings (36, 37) are located. When the two heat transfer plates (33) are put together, the recesses (38, 38) allow each panel (3
The internal space of 2) is formed. The concave fitting portion (38) communicates with an inlet opening (36) and an outlet opening (37) at upper and lower ends.

The concave fitting portion (38) has a large number of ridges (39) extending in the horizontal direction in order to form a water flow path. The ridges (39) are vertically arranged in the concave fitting portion (38). The end surface of each ridge (39) is located on the same plane as the end surface (joint surface) of the joint (34). These ridges
(39) is slightly shorter than the left and right width of the concave fitting portion (38), and the concave fitting portion (3
8) It is located alternately on the right side and on the left side. In this way, the numerous ridges (39) are formed in an arrangement in which comb teeth are engaged with each other from the left and right, and a water flow path is provided therebetween.

The inlet opening (36) and the outlet opening (37) are formed in the shape of a short rectangular tube protruding outward from the heat transfer plate (33), and the ends thereof are formed at the bottom of the concave fitting portion (38). (The heat transfer surface). Further, a plurality of convex portions (40) projecting in a truncated cone shape are formed on the peripheral edge portion (34) of the heat transfer plate (33) at predetermined intervals over the entire periphery thereof. The end face of each projection (40) has an inlet opening (36) and an outlet opening (3
It is located on the same plane as the end face of 7). And the entrance opening
(36), the outlet opening (37), and the convex portion (40) are formed to have a larger protruding height than the concave fitting portion (38).

Further, openings (41, 42) for attaching headers are formed in the protective plate (35) at positions corresponding to the inlet opening (36) and the outlet opening (37) of the heat transfer plate (33). Have been.

FIG. 8 is an exploded perspective view of the heat exchanger unit (31). In this figure, the heat transfer plate (33)
Although only four heat transfer plates (33) are used in practice, a larger number and an even number of heat transfer plates (33) are used. Heat transfer plate (33)
Are joined by heating the two pieces together in a state where the brazing material is applied to the inner surface side of the peripheral portion (34) of the panel (32) and the end face of the ridge (39), whereby each panel ( 32) is formed. Further, each panel (32) is joined by overlapping and heating a plurality of panels with the brazing material applied to the end faces of the inlet opening (36) and the outlet opening (37) and the end face of the convex portion (40). You.

The projecting height of the inlet opening (36), the outlet opening (37) and the projecting portion (40) is larger than the projecting height of the concave fitting portion (38). In the above, a space is formed between the heat transfer surfaces of the adjacent panels (32).
Thus, condensed water or a high concentration solution can be supplied to the outer surface of each panel (32). In addition, each panel (32)
Since the inlet opening (36) and the outlet opening (37) are continuously joined, the inlet opening (36) and the outlet opening (37)
An entrance passage (36, 36, ...) communicating with the internal space of each panel (32)
・) And outlet passages (37, 37, ・ ・).

As shown in FIG. 8, the protection plate (3
Header pipes (43, 44) are attached to the openings (41, 42) of (5). The protection plate (35) is joined to the panel (32) by brazing.

The heat exchanger unit thus formed
By joining a plurality of (31) as shown in FIG. 9, the plate heat exchanger (30) is formed. In the present embodiment, the header pipes (43, 44) of the protection plate (35)
By joining each other, multiple heat exchanger units (31, 31, ...)
Are joined. That is, the header pipes (43, 44) also serve as connection pipes for connecting the heat exchanger units (31).
In the completed plate heat exchanger (30), the header pipes (43, 44) on one side of the protection plates (35, 35) at both ends are closed. Alternatively, a protective plate (35) in which the openings (41, 42) are closed in advance may be used on the closed side.

When the heat exchanger unit (31) is prepared, as described above, the heat transfer plate (33) is
After a plurality of panels (32) are formed by bonding them one by one, these panels (32) and two protective plates (35) may be combined to form a heat exchanger unit (31). , 4
The heat exchanger unit (31) may be formed at a time by using more than one (even number) heat transfer plates (33) and two protective plates (35) and superposing and heating them. .

In the plate heat exchanger configured as described above, the water flowing from the inlet passages (36, 36,...) Branches into the respective panels (32) and flows through the respective panels (32). It flows upward from the bottom, then merges and exits through the outlet passages (37, 37, ...).

-Spraying device-On the other hand, in the low-pressure body (13), the upper part of each evaporator (14, 15) and the upper part of each absorber (16, 17) are arranged at the top and bottom.
Each is provided with a spraying device (25, 26). 10 to 13 show an upper spraying device (25) for the low-pressure side evaporator (14) and the low-pressure side absorber (16). 10 is a plan view of the upper spraying device (25), FIG. 11 is a front view, FIG. 12 is a side view, and FIG. 13 is a partially enlarged view. In addition, this upper spraying device (25)
Accordingly, the condensed water of the condenser (4) is sprayed on the low-pressure side evaporator (14), and the high-concentration solution from the low-temperature generator (3) is sprayed on the low-pressure side absorber (16).

As shown in the figure, a solution pipe (18) or a condensed water pipe (19) is provided above a plate heat exchanger (30) constituting the low pressure side evaporator (14) and the low pressure side absorber (16). ) (See FIG. 1) is provided with a header pipe (51). The header pipe (51) has a rectangular cylindrical shape, and both ends are closed by end plates (52). And the distribution part (53) is provided in the header pipe (51) in the position corresponding to each heat exchanger unit (31).

Each distributing section (53) includes a bottom plate (54a) and a front plate (54b).
Are formed in a tub shape from an L-shaped plate (54) in which are integrated and side plates (55) attached to both ends thereof. And, on the side surface (51a) of the header pipe (51), each distribution part (5
A plurality of small holes (51b) communicating with (3) are formed, and a plurality of small holes (54c) are also formed in the bottom plate (54a). ).

At the upper end of each heat exchanger unit (31), a liquid reservoir (46) is provided for each panel (32) (omitted in FIGS. 4 to 9). The liquid is passed from the distributor (53) to the liquid reservoir (46). The liquid reservoirs (46) of each panel (32) are arranged closely. A communication hole (47a) for connecting the liquid reservoirs (46) to each other is provided on the contact surface of the liquid reservoir (46) of each panel (32), as shown in FIG.

A small hole is formed in the lower surface of the liquid reservoir (46) of each panel (32).
(47b) is formed. Also, each panel (32) and panel
Between (32), a guide plate formed by bending into a substantially U-shape
(48) are provided in such a manner that the upper side is a bent portion so as to leave a slight gap from each panel (32). The guide plate (48) has a plurality of small protrusions (48a) on the contact surface with each panel (32), and also has convex portions (48b) projecting downward at both longitudinal ends of the lower edge. Have. As a result, a small gap is secured between the guide plate (48) and each panel (32), and the liquid passes through the gap and travels on the heat transfer surface.

As described above, the guide plate (48) is provided between the adjacent panels (32), and the liquid is transmitted between the guide plate (48) and the panel (32). , Simply the panel (3
If the liquid is simply dropped into the space between 2) and the panel (32), the liquid may flow in a streak form and the wettability may be reduced. Enhanced.

Further, in this embodiment, as described above, the headers (43, 44) are integrally formed with the plate-type heat exchanger (30), and the liquid is evenly applied to the plate-type heat exchanger (30). The configuration for distribution is also integrated, and these are unitized. Therefore, it is possible to easily assemble the device.

The high pressure side evaporator (15) and the high pressure side absorber
The lower spraying device (26) for (16) is not shown in detail,
A liquid seal structure is adopted to maintain a pressure difference between the low pressure side and the high pressure side of the low pressure cylinder (13). The point that the solution or the condensed water is evenly distributed to the panel (32) of each heat exchanger (30) is the same as the upper spraying device (25).

-Operating operation- Next, the operating operation of the absorption refrigeration system (1) of the present embodiment will be described.

First, in the high-temperature generator (2), the aqueous lithium bromide solution is heated by the gas burner (11) to generate high-temperature steam, and the aqueous lithium bromide solution is concentrated to an intermediate concentration. Then, the high-temperature steam generated in the high-temperature generator (2) is introduced into the condenser (4) through the low-temperature generator (3), while the intermediate-concentration aqueous lithium bromide solution is supplied to the low-temperature generator (3). be introduced. In the low-temperature generator (3), the intermediate-concentration lithium bromide aqueous solution is heated by the high-temperature steam to generate steam, and the lithium bromide aqueous solution is concentrated to a high concentration.

The steam generated in the high-temperature generator (2) is cooled when passing through the low-temperature generator (3) and is introduced into the condenser (4). Also, the steam generated by the low-temperature generator (3) is introduced into the condenser (4). In the condenser (4), high-temperature steam exchanges heat with cooling water to condense and liquefy. The liquefied condensed water flows through the condensed water pipe (19) to the low-pressure evaporator (5),
The heat exchanges with the cooling water or the like flowing through the use side circuit (10) to evaporate, thereby cooling the cooling water.

At this time, the evaporation process of the condensed water is performed in two stages, the low pressure side and the high pressure side, in the low pressure body (13). That is, when the condensed water dropped on the low-pressure side evaporator (14) by the upper spraying device (25) travels down the surface of each panel (32) of the heat exchanger (30), the low-pressure side evaporator Each panel of (14)
While exchanging heat with the cooling water flowing from the bottom to the top in the (32), when the condensed water further flowing down from the low-pressure side evaporator (14) drops from the lower sprayer (26) to the high-pressure side evaporator (15), The condensed water exchanges heat with the cooling water flowing in the high-pressure side evaporator (15) to evaporate. In the low-pressure cylinder (13), water drops and water vapor are separated by the eliminator (24), and only the water vapor is absorbed by the absorber (6).
To

On the other hand, the high-concentration aqueous solution of lithium bromide concentrated in the low-temperature generator (3) flows through the solution pipe (18) and passes through the absorber.
(6). The aqueous lithium bromide solution is cooled by absorbing water vapor flowing from the evaporator (5) and exchanging heat with cooling water. This absorption step is also performed in two stages, like the evaporation step. In other words, first, the absorption process of the high-concentration aqueous solution from the low-temperature generator (3) and the water vapor from the low-pressure side evaporator (14) is performed in the low-pressure side absorber (16), and then the lithium bromide that has been diluted somewhat is removed. The intermediate-concentration aqueous solution is introduced from the lower spraying device (26) into the high-pressure side absorber (17), and a second absorption process is performed with the steam from the high-pressure side evaporator (15), and the lithium bromide aqueous solution is removed to a predetermined low level. Diluted to a concentration.

As described above, the lithium bromide aqueous solution diluted by absorbing water vapor in the absorber (6) in two stages is:
The solution is sent to the high-temperature generator (2) by a solution pump (not shown) and concentrated again. At this time, the low-concentration aqueous solution of lithium bromide diluted in the absorber (6) exchanges heat with the high-concentration aqueous solution of lithium bromide in the low-temperature heat exchanger (7), and then the high-temperature heat exchanger
In step (8), heat exchange is performed with an aqueous solution of lithium bromide having an intermediate concentration. This heats the dilute aqueous lithium bromide solution supplied to the high-temperature generator (2) while recovering the heat of the concentrated aqueous lithium bromide solution sent to the absorber (6).

Thus, one cycle of the flow of the aqueous solution of lithium bromide in the absorption refrigeration system (1) is completed. Thus, the lithium bromide aqueous solution is converted into a high-temperature
By repeating the above-described cycle while heating in the above, the cold water in the use side circuit (10) is cooled, so that the generated cold heat can be used for cooling or the like.

According to the present embodiment, since the evaporator (5) and the absorber (6) are constituted by the plate type heat exchanger (30), the evaporator
The size of the apparatus can be reduced as compared with a conventional two-stage absorption refrigeration apparatus using a shell-and-tube heat exchanger for the (5) and the absorber (6). In particular, evaporator (5) and absorber
Because all of (6) is a plate heat exchanger (30),
Significant miniaturization can be realized.

In the shell-and-tube type heat exchanger, it is necessary to insert and fix a number of heat transfer tubes into the tube sheet, and the assembling work is complicated. However, the plate type heat exchanger (30) The workability is improved by using
The processing cost is reduced, and the cost of the apparatus itself is also reduced.

Further, even in the case of a plate type heat exchanger using hollow panels, for example, each panel (32) is opened at the entrance.
(36) and the outlet opening (37) in the case of connecting via a short pipe, it is difficult to manufacture because there are many connecting steps, but in the above embodiment, the plate-type heat exchanger ( An inlet opening (36) and an outlet opening (37) are formed by press working on each panel (32) of the 30), and a brazing material is applied to the protruding ends of both openings (36, 37), and each panel (32) ) It is brazed by heating in the state of overlapping each other, so
The inlet passage (36,36, ...) and the outlet passage (37,
37, ..) can be manufactured. That is,
There is an advantage that the manufacture of the plate heat exchanger (30) is facilitated.

Further, in this embodiment, header pipes (43, 44) are provided on the protection plate (35) of each heat exchanger unit (31), and the header pipes (43, 44) are connected to each other to form a plate type. Since the heat exchanger (30) is configured, the heat exchanger units (31) can be easily connected to each other.

Further, since the protection plates (35) are provided at both ends of the heat exchanger unit (31), each panel (32) is protected while ensuring the strength of the heat exchanger unit (31). it can. In other words, since each panel (32) is formed to be thin in terms of heat exchange performance, it is difficult to secure sufficient strength without the protection plate (35), and it is difficult to attach header piping (43, 44) etc. While a defect such as a hole is likely to occur, the provision of the protection plate (35) increases the strength performance while securing the heat transfer performance.

Further, since the headers (43, 44) connected to the protection plate (35) are also integrated with the heat exchanger unit (31), they are excellent in handling such as pipe connection.

Further, since the plate heat exchanger (30) has a structure in which a plurality of heat exchanger units (31) are connected,
Even if the number of panels (32) of each heat exchanger unit (31) is relatively small, connecting the heat exchanger units (31) to each other enables the plate type heat exchanger (30 )
Can be easily configured. And each heat exchanger unit (31)
Since it can be made compact, it can be easily handled, such as assembling it to the low-pressure body (13) and storing stock.

In this embodiment, each plate-type heat exchanger (30) is described as being composed of a plurality of heat exchanger units (31). However, for example, four heat exchanger units (31) are provided.
Are connected in series as shown in FIG. If a configuration is used in which a plurality of heat exchanger units (31) are connected in this way, the same heat transfer plate (33)
Thus, it is possible to use a unit (31) in which the same number of panels (32) are arranged, and to cope with a change in performance only by changing the number of the units (31).

[0069]

Other Embodiments of the Invention The present invention may be configured as follows with respect to the above embodiment.

For example, in the above embodiment, the evaporator is connected by connecting a plurality of heat exchanger units (31) in series.
(5) and a plate-type heat exchanger (3) used as an absorber (6)
0), but the plate heat exchanger (30)
A plurality of heat exchanger units (31) may be connected in parallel.

Further, depending on the capacity of the refrigerating apparatus, one heat exchanger unit (31) may be used as a plate type heat exchanger (30) and used for the evaporator (5) and the absorber (6). . In this case, the header pipe (43) for the inlet passage (36, 36, ...) and the header for the outlet passage (37, 37, ...) are provided on one side of the protection plate (35) of the heat exchanger unit (31). A pipe (44) may be provided, and the other of the protection plates (35) may be closed at the openings (41, 42).

In the above embodiment, the heat exchanger units (31) are connected to each other via the header pipes (connection pipes) (43, 44) provided on the protection plate (35). Alternatively, as shown schematically in FIG. 15, the plate type heat exchanger (30) may be constructed by directly connecting the protection plates (35) without using the connecting pipes (43, 44). If you do this,
Since the plate-type heat exchanger (30) can be downsized compared to the connection via the header pipes (43, 44), the apparatus can be further downsized. This is particularly advantageous when the number of connected heat exchanger units (31) is large.

Further, in the above embodiment, the plate type heat exchanger (30) is used for the evaporator (5) and the absorber (6), but the plate type heat exchanger is used only for the evaporator (5). Using a shell-and-tube heat exchanger for the absorber (6) using the (30), or a plate-type heat exchanger (30) only for the absorber (6)
It is also possible to use a shell and tube type heat exchanger for the evaporator (5). In addition, evaporator (5)
And the absorber (6) with only the upper ones (14, 16) as plate heat exchangers (30) and the lower ones (15, 17) as shell and tube heat exchangers, or vice versa. Side stuff (15,17)
Only plate type heat exchanger (30) and upper one (14, 16)
Can be used as a shell-and-tube heat exchanger. Further, a part of the evaporator (14, 15) and / or a part of the absorber (16, 17) may be a plate heat exchanger (30), and the rest may be a shell and tube heat exchanger.

In some cases, other plate heat exchangers (low-temperature generator (3), condenser (4), low-temperature heat exchanger (7), high-temperature heat exchanger (8)) may be used. (30) can be used, and when performing an absorption refrigeration cycle of three or more stages, all or a part of the evaporator (5) and the absorber (6) may be a plate-type heat exchanger. It is also possible to use a vessel (30).

If two or three or more absorption refrigeration cycles are performed, a plurality of evaporators (14,
15) and a plurality of absorbers (16, 17) may be arranged other than in a vertical positional relationship.

In the above embodiment, the present invention is applied to a case where a two-stage absorption refrigeration cycle is performed by a double effect absorption refrigeration system using water as a refrigerant and lithium bromide as an absorption medium. However, the present invention is not limited to a double effect device, and may be a single effect absorption refrigeration device.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of an absorption refrigeration apparatus according to an embodiment of the present invention.

FIG. 2 is a structural view of a low-pressure body seen from the front side.

FIG. 3 is a structural view of a low-pressure body seen from a side.

FIG. 4 is a perspective view of a plate heat exchanger configured by connecting a plurality of heat exchanger units in series.

FIG. 5 is a perspective view showing an inner shape of a heat transfer plate constituting a panel of the plate heat exchanger.

FIG. 6 is a perspective view showing an outer shape of a heat transfer plate constituting a panel of the plate heat exchanger.

FIG. 7 is a perspective view illustrating an external shape of a protection plate of the plate heat exchanger.

FIG. 8 is an exploded perspective view of the heat exchanger unit.

FIG. 9 is a perspective view showing a state where a plurality of heat exchanger units are joined.

FIG. 10 is a plan view of the spraying device.

FIG. 11 is a front view of the spraying device.

FIG. 12 is a side view of the spraying device.

FIG. 13 is a partially enlarged view of the spraying device.

FIG. 14 is a schematic view of a plate heat exchanger constituted by four heat exchanger units.

FIG. 15 is a diagram showing a modification of FIG.

[Explanation of symbols]

 (1) Absorption refrigerator (2) High temperature generator (3) Low temperature generator (4) Condenser (5) Evaporator (6) Absorber (7) Low temperature heat exchanger (8) High temperature heat exchanger (9 ) Cooling water pipe (10) Cold water pipe (use side circuit) (13) Low pressure body (14) Low pressure side evaporator (15) High pressure side evaporator (16) Low pressure side absorber (17) High pressure side absorber (25 , 26) Sprayer (30) Plate heat exchanger (31) Heat exchanger unit (32) Panel (33) Heat transfer plate (35) Protection plate (36) Inlet opening (37) Outlet opening (36,36,・ ・) Inlet passageway (37,37, ・) Outlet passageway (43,44) Header piping (connecting piping)

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 000002853 Daikin Industries Co., Ltd. 2-4-1-12 Nakazaki Nishi, Kita-ku, Osaka-shi, Osaka Umeda Center Building (72) Inventor Atsushi Shitara 1-5-2, Kaigan, Minato-ku, Tokyo No. Tokyo Gas Co., Ltd. (72) Kenji Yamada, inventor 1-3-1 Kitako Shiratsu, Konohana-ku, Osaka-shi, Osaka No. Osaka Gas Co., Ltd. Inside Gas Company (72) Kenji Yasuda, Inventor 1304, Kanaokacho, Sakai City, Osaka Prefecture Daikin Industries, Ltd.Kanaoka Plant (72) Inventor Mitsuharu Numata, 1304, Kanaokacho, Sakai City, Osaka Daikin Industries, Ltd. Inside the Kanaoka Plant (72) Inventor Mitsuji Kawai 1304 Kanaokacho, Sakai City, Osaka Daikin Industries Kanaoka Works, Sakai Plant Co., Ltd. The internal F-term (reference) 3L093 AA05 BB12 BB13 BB22 LL03 MM02 3L103 AA05 BB50 CC02 DD13 DD44 DD52

Claims (5)

[Claims] 1. An absorption refrigerating apparatus in which an evaporator (5) and an absorber (6) are provided in two stages, respectively, to perform a two-stage absorption refrigerating cycle. 6) are each configured by a plate-type heat exchanger (30), the plate-type heat exchanger (30) is configured by a heat exchanger unit (31), and the heat exchanger unit (31) includes a plurality of heat exchanger units (31). Hollow panels (32) are arranged at predetermined intervals and integrated, and each panel
An inlet passageway (36, 36, ...) and an outlet passageway (37, 37, ...) communicating with the internal space of (32), and the outside of the panel (32) at both ends connected by brazing or welding And a protection plate (35) for protecting the panel (32). 2. The plate heat exchanger (30) is formed by connecting a plurality of heat exchanger units (31).
The absorption type refrigeration apparatus according to the above. 3. The absorption refrigeration system according to claim 1, wherein the plate heat exchanger (30) is constituted by connecting a plurality of heat exchanger units (31) in series. 4. The plate type heat exchanger (30) comprises a plurality of heat exchanger units (31) connected between the heat exchanger units (31) through connection pipes (43, 44). The absorption refrigeration apparatus according to claim 3. 5. The absorption refrigeration system according to claim 3, wherein the plate type heat exchanger (30) has the protection plates (35) of the plurality of heat exchanger units (31) directly connected to each other.