JPH0996459A - Heat-exchanger for absorption refrigerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a high or intermediate concentration absorbent from boiling in a heat-exchanger due to a pressure reduction by a method wherein plates to partition respective absorbent passages are laminated in a casing, and a high concentration absorbent passage has a high concentration absorbent outlet for which an outlet pipe with contracting holes on the top is inserted while penetrating almost all the plates. SOLUTION: In a main body 61, an open hole 64a for a specified inlet, an open hole 64b for outlet, and an unevenness 64c to partition two kinds of absorbents, a high concentration absorbent which flows upward and a low concentration absorbent which flow downward, are provided. A large number of plates 64 are fitted in, and an absorbent passage is formed between respective plates 64. On the left side of an intermediate part of a lid body 63, a high concentration absorbent inlet 75 is formed, and on the right side of the upper end part, a high concentration absorbent outlet 76 is formed. Then, a high concentration absorbent passage L4 facing the upper end from an intermediate part of a casing 6, is provided. The high concentration absorbent outlet 76 is formed in such a manner that an outlet pipe 8 on which a slit 81 in the axial direction is provided so that it may communicate with respective high concentration absorbent passages L4, as a contracting hole 82, is made to penetrate almost all the plates 64.

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 using an aqueous solution such as lithium bromide as an absorption liquid.

[0002]

2. Description of the Related Art In an absorption type refrigerating apparatus, an aqueous solution (absorption liquid) of low concentration such as lithium bromide is heated and boiled in a high temperature regenerator to obtain a solution (refrigerant) such as water and an intermediate concentration absorption liquid (absorption liquid). Lithium bromide solution of medium concentration). Further, the low-temperature regenerator re-evaporates the refrigerant from the medium-concentration absorbent to generate a high-concentration absorbent. The refrigerant is liquefied in a condenser provided with a cooling coil, supplied to the evaporator, and takes heat of evaporation from the evaporation coil arranged in the evaporator to evaporate. The high-concentration absorption liquid is guided to an absorber provided with a cooling coil, absorbs the refrigerant that has been dropped on the cooling coil and then evaporated to become a low-concentration absorption liquid, and is returned to the high temperature regenerator.

The low concentration absorbent returned to the high temperature regenerator has a low temperature, the high concentration absorbent supplied to the absorber has an intermediate temperature, and the medium concentration absorbent supplied to the low temperature regenerator has a high temperature. There is. From the viewpoint of thermal efficiency, it is desirable that the low concentration absorbent has a high temperature and the high concentration absorbent has a low temperature. For this reason, the absorption refrigerating apparatus is provided with a heat exchanger for exchanging heat between the high-concentration absorption liquid or the medium-concentration absorption liquid and the low-concentration absorption liquid.

[0004]

In the heat exchanger of this absorption refrigeration system, when the inlet of the high-concentration absorbing liquid or the medium-concentrating absorbing liquid is downward and the outlet is upward, the pressure becomes lower as it flows upward due to the head difference. . Further, the outlet is connected to a low temperature regenerator or an absorber, and the pressure becomes lower as the flow path itself goes downstream. For these reasons, as the gas flows downstream in the heat exchanger, the pressure is reduced, the absorbing liquid is evaporated, and vapor lock is likely to occur. If this vapor lock occurs in the heat exchanger, there arises a problem that the heat exchange rate with the low-concentration absorbent is lowered. An object of the present invention is to prevent the high-concentration absorbent or the medium-concentrated absorbent from depressurizing and boiling in the heat exchanger, so that the smooth flow and reliable heat exchange in the liquid phase in the heat exchanger are ensured. It is possible to provide a heat exchanger for an absorption type refrigeration system.

[0005]

The present invention comprises a heating source,
A high-temperature regenerator having a heating tank for boiling the low-concentration absorption liquid by the heating source to separate it into a refrigerant and a medium-concentration absorption liquid, and a refrigerant recovery tank for recovering the evaporated refrigerant, and a medium concentration using the refrigerant recovery tank as a heat source. A low-temperature regenerator that reboils the absorption liquid and separates it into a refrigerant vapor and a high-concentration absorption liquid, a condenser that condenses the refrigerant generated by the high-temperature regenerator and the low-temperature regenerator, and evaporates the condensed refrigerant liquid. An evaporator for cooling the cold / hot water for cold heat source, and a refrigerator main body including an absorber for absorbing the evaporated refrigerant vapor into the high-concentration absorption liquid,
The high-concentration absorption liquid generated in the low-temperature regenerator is passed through the high-concentration absorption liquid heat exchanger to exchange heat with the low-concentration absorption liquid discharged from the absorber, and then the high-concentration absorption liquid is introduced into the absorber. In the absorption type refrigerating apparatus including a liquid flow path, the high-concentration absorbent heat exchanger has a structure in which plates for partitioning the respective absorbent paths are stacked in a casing, The flow path has a high-concentration absorbent inlet at a lower part of the casing and a high-concentration absorbent outlet at an upper part, and the high-concentration absorbent outlet is provided for each high-concentration absorbent formed between the stacked plates in the casing. It is characterized in that an outlet pipe with a throttle hole communicating with the liquid flow path is formed by inserting substantially all plates into the casing.

According to the second aspect of the present invention, the heating source, the heating tank for boiling the low-concentration absorption liquid by the heating source to separate it into the refrigerant and the medium-concentration absorption liquid, and the refrigerant recovery tank for recovering the evaporated refrigerant. A high-temperature regenerator having a low-temperature regenerator for re-boiling the medium-concentration absorbent using the refrigerant recovery tank as a heat source to separate the refrigerant vapor and the high-concentration absorbent into the high-temperature regenerator and the low-temperature regenerator. Refrigerator body consisting of a condenser for condensing the condensed refrigerant, an evaporator for evaporating the condensed refrigerant liquid to cool the cold / hot water for the cold heat source, and an absorber for absorbing the evaporated refrigerant vapor into the high-concentration absorption liquid And the high-concentration absorbent produced in the low-temperature regenerator is passed through the high-concentration absorbent heat exchanger to exchange heat with the low-concentration absorbent discharged from the absorber, and then introduced into the absorber. Concentrated absorbent flow path The concentration absorption solution in generated in the regenerator,
In an absorption type refrigerating apparatus having a medium-concentration absorbent liquid flow path that leads to the low-temperature regenerator after heat exchange with the low-concentration absorbent liquid discharged from the absorber by passing through the medium-concentration absorbent liquid heat exchanger, The medium-concentration absorption liquid heat exchanger has a structure in which medium-concentration plates that partition the respective absorption liquid channels are stacked in the medium-concentration casing, and the medium-concentration absorption liquid channel is the medium-concentration casing. The medium-concentration absorption liquid inlet is provided at the lower level, and the middle-concentration absorption liquid outlet is provided at the upper level. Is formed by inserting an outlet pipe with a throttle hole communicating with the inside of the medium-concentration casing through almost all the medium-concentration plates and exchanging the low-concentration absorption liquid discharged from the absorber with the high-concentration absorption liquid heat exchange. And heat exchange of medium-concentration absorbent Intermediate concentration absorption solution and the high concentration absorption solution and heat-exchanged by, characterized in that a low concentration absorption solution flow path for feeding back into the high-temperature regenerator.

In the structure according to the third aspect, the high-concentration absorbent heat exchanger and the medium-concentration absorbent heat exchanger are provided vertically in the same vertically elongated casing, and the low-concentration absorbent The flow passage has a low-concentration absorbent inlet at the upper end of the casing and a low-concentration absorbent outlet at the lower end, and is formed along the entire length of the casing. A high-concentration absorbent inlet is provided in the middle of the casing, and a high-concentration absorbent inlet is formed along the middle of the casing along the middle of the casing. It has a concentration absorbing liquid outlet and is formed along the upper end from the middle of the casing.

In the heat exchanger of the absorption refrigerating device according to the fourth aspect, the throttle hole is constituted by an axial slit formed in the outlet pipe. In the heat exchanger of the absorption refrigeration apparatus according to the fifth aspect, the throttle hole is formed in the upper part of the outer peripheral surface of the outlet pipe.

[0009]

The heat exchanger of the absorption refrigerating apparatus of the present invention has a high-concentration absorption liquid outlet or a medium-concentration absorption liquid heat exchanger medium concentration of the high-concentration absorption liquid heat exchanger arranged above. Since the absorbing liquid outlet is formed by the outlet pipe with a throttle hole which communicates with each flow path in the casing, it is possible to prevent the pressure drop of the high-concentration absorbing liquid or the medium-concentrating absorbing liquid in the heat exchanger.
As a result, it is possible to prevent the occurrence of vapor lock due to the pressure reduction of the absorbing liquid in the heat exchanger.

Further, in the heat exchanger, a plurality of partitioned absorption liquid flow paths are formed between the laminated plates, and the flow rate of each absorption liquid flow path is restricted by the restriction holes. Therefore, on the upstream side of the outlet pipe, the liquid state of the absorbing liquid is kept uniform in each of the absorbing liquid flow paths, and uneven flow is prevented.
As a result, a smooth flow of the absorbing liquid can be obtained, and the heat exchange efficiency with the low-concentration absorbing liquid can be improved.

According to the third aspect of the present invention, the high-concentration absorbing liquid heat exchanger and the medium-concentrating absorbing liquid heat exchanger are integrated so that the wearability can be improved. With the configuration according to the fourth aspect, it is possible to easily form the aperture hole. In the structure according to the fifth aspect, the effect of the throttling is easily made uniform in the length direction of the throttling hole, and the flow is uniform because the uneven flow is strongly prevented, and the effect of improving the heat exchange efficiency is great.

[0012]

1 to 3 show a heat exchanger H in which a high-concentration absorption liquid heat exchanger and a medium-concentration absorption liquid heat exchanger are integrated.
Is attached to the refrigerator main body 200 of the absorption refrigeration apparatus 100 shown in FIG. The refrigerator main body 200 has a vertical cylindrical shape, and the heat exchanger H has a vertically long and flat box shape.
It is vertically fastened to the outer wall surface of the refrigerator main body 200 and is housed in one side of the housing A. On the other side of the housing A, a cooling tower (cooling tower) CT and a cooling blower CB shown in FIG. 5 are housed.

As shown in FIG. 5, the absorption refrigeration system 100 includes a refrigerator main body 200 and a cooling tower (cooling tower).
It is composed of CT and an indoor unit CU is attached to form a cooling / heating device. The absorption refrigeration system 100 includes a high temperature regenerator 1 for heating and boiling a low concentration absorption liquid to separate it into a medium concentration absorption liquid and a refrigerant vapor.

The high temperature regenerator 1 comprises a heating tank 11 and a heating tank 1 in which a gas burner B as a heating source is arranged below.
1 is provided with a medium-concentration absorbent partition 12 that is a cylinder that extends upward from the upper end and that has an open upper end, and a refrigerant recovery tank 10 that is a vertical cylindrical container that is disposed on the outer periphery of the middle-concentration absorbent partition 12. .

In the middle-concentration absorbent partition 12, the middle-concentrated absorbent having a medium concentration due to the evaporation of the refrigerant remains in the lower portion 121, and the middle-concentrated absorbent is boiled from the upper end opening 122 (refrigerant vapor).
Is blowing into the refrigerant recovery tank 10. A low temperature regenerator 2 having a function of improving thermal efficiency is provided on the outer periphery of the refrigerant recovery tank 10.

The low temperature regenerator 2 has a vertical cylindrical shape, and is provided with a low temperature regenerator case 20 having a refrigerant vapor outlet 21 opened on the ceiling. In the low-temperature regenerator case 20, heat is passed from the lower portion 121 of the medium-concentrated absorbent partition 12 through the lower half of the heat exchanger H (medium-concentrated absorbent heat exchanger portion) through the medium-concentrated absorbent flow path L1. The exchanged medium-concentration absorption liquid is supplied. The medium-concentration absorption liquid is re-evaporated by using the outer peripheral surface of the refrigerant recovery tank 10 as a heat source, and is separated into the high-concentration absorption liquid and the refrigerant vapor.

An airtight, vertical cylindrical evaporation / absorption case 30 is concentrically installed on the outer periphery of the low temperature regenerator 2. An absorber 3 is provided in the evaporation / absorption case 30, and an evaporator 4 is provided on the outer periphery of the absorber 3. On the outer periphery of the low temperature regenerator 2 and above the evaporation / absorption case 30, an airtight vertical cylindrical condenser case 50 is concentrically installed, and a condenser 5 having a cooling coil 51 arranged therein is provided.
Is provided.

In the absorber 3, a cooling coil 31 wound in a vertical cylindrical shape is arranged inside the evaporation / absorption case 30, and a high-concentration absorbent is sprayed above the cooling coil 31. A high-concentration absorbent sprayer 32 is attached. The evaporator 4 includes an evaporation coil 41 wound in a vertical cylindrical shape on the outer side of the evaporation / absorption case 30, and a refrigerant liquid sprinkler 42 arranged above the evaporation coil 41.

High temperature regenerator 1, low temperature regenerator 2, absorber 3,
The evaporator 4 and the condenser 5 are concentrically arranged and, as shown in FIG. 4, are integrally welded to form a vertical cylindrical refrigerator main body 200. The refrigerator main body 200 is
It is supported by a stand 201 and stands vertically inside the housing A.

Between the bottom of the absorber 3 and the bottom of the heating tank 11, the low-concentration absorbing liquid discharged from the absorber 3 is passed through the whole part from the upper end to the lower end of the heat exchanger H, They are connected by a low-concentration absorbent liquid flow path L2 for returning to the heating tank 11 of the high temperature regenerator 1. Low concentration absorbent flow path L
An absorption liquid pump P1 for circulating a low-concentration absorption liquid is installed at 2.

The upper part of the low-temperature regenerator 2 is a gas-liquid separating part 22, which is separated from the upper part of the condenser 5 by a gap 5.
It communicates via A. The lower part 121 of the medium-concentration absorbent partition 12 communicates with the top or bottom (the top in the figure) of the low-temperature regenerator 2 through the middle-concentration absorbent flow path L1.

A refrigerant liquid receiving portion 10a is provided between the refrigerant recovery tank 10 and the medium-concentration absorbing liquid partition cylinder 12, and communicates with the condenser 5 through a refrigerant flow path L3. The refrigerant liquid is sucked by the low pressure in the condenser case 50 and supplied to the condenser 5. A part of the refrigerant liquid flowing into the condenser 5 is vaporized due to the low pressure, and the vaporized refrigerant is cooled and condensed by the cooling coil 51 together with the refrigerant of the low temperature regenerator supplied from the gap 5A.

High-concentration absorbent receiving part 23 of low-temperature regenerator 2
Is connected to the high-concentration absorbent sprayer 32 of the absorber by the high-concentration absorbent flow path L4. The high-concentration absorption liquid is sucked by the low pressure in the evaporation / absorption case 30 and passes through the upper half of the heat exchanger H (high-concentration absorption liquid heat exchanger portion) for heat exchange, and then the high-concentration absorption liquid sprayer 32.

The lower part of the condenser 5 and the evaporation coil 4 of the evaporator 4
The refrigerant liquid spraying tool 42 installed above 1 is communicated with the refrigerant liquid supply path L5. The refrigerant is sprayed from the refrigerant liquid spraying tool 42 onto the surface of the evaporation coil 41, takes the evaporation heat from the evaporation coil 41 and evaporates, and cools cold / hot water as a heat medium flowing through the inside of the refrigerant coil of the absorber 3. The surface of 31 is absorbed by the high-concentration absorbent dropped from the high-concentration absorbent sprayer 32. The absorbing liquid that has absorbed the refrigerant and becomes a low concentration,
It is returned to the heating tank 11 by the low-concentration absorbent flow path L2.

The cooling coil 31 is connected to the cooling coil 51, and is further connected to the cooling tower CT through the cooling water circulation path 33, and the cooling water is supplied from the cooling water pump P2 to the cooling tower CT → cooling coil 31 → cooling coil 51 → It circulates in the order of the cooling tower CT. The evaporation coil 41 is connected to the indoor unit CU through a cold / hot water circulation path 43 having a cold / hot water pump P3.

As shown in FIGS. 1 to 3, the heat exchanger H has a casing 6 having a vertically elongated rectangular cross section, and brackets 60, 60 welded to the side surfaces of the casing 6 are provided on the outer wall surface of the refrigerator main body 200. It is fastened to 202 with fasteners. The casing 6 includes a container body 61 that is press-molded and a lid body 63 that is press-molded and has a fitting edge 62 provided around the outer periphery thereof. The lid 63 is fitted in the main body 61 and the fitting surface is welded.

Inside the main body 61, there are formed a predetermined inlet opening 64a, an outlet opening 64b, and a high-concentration absorbing liquid flowing upward and a low-concentration absorbing liquid flowing downward.
A large number of plates 64 provided with concavities and convexities 64c for partitioning the seed absorbing liquid are fitted into the plates 64, 64.
An absorbing liquid flow path is formed between them. In addition, the formed absorption liquid flow paths alternately flow absorption liquids of different concentrations,
One of the flowing absorbing liquids is different between the upper and lower parts in the main body 61.

That is, in the upper half of the main body 61, the high-concentration absorption liquid and the low-concentration absorption liquid flow, and in the lower half, the medium-concentration absorption liquid and the low-concentration absorption liquid flow. Note that FIG. 1 shows details of the upper half of the heat exchanger H. The lid 63 has a low-concentration absorbent inlet 71 at the upper left corner and a low-concentration absorbent outlet 72 at the lower right corner, and has a low-concentration absorbent flow path from the upper end to the lower end in the casing 6. L2 is provided.

A middle-concentration absorption liquid inlet 73 is provided on the left side of the lower end of the lid 63, and a middle-concentration absorption liquid outlet 74 is provided on the right side of the middle part. A flow path L1 is provided. A high-concentration absorbent inlet 75 is formed on the left side of the middle part of the lid 63, and a high-concentration absorbent outlet 76 is formed on the right side of the upper end, and the high-concentration absorbent flow path extends from the middle to the upper end of the casing 6. L4 is provided.

That is, in this embodiment, the casing 6
The upper half is the high-concentration absorbent heat exchanger and the lower half is the medium-concentrated absorbent heat exchanger. As in this embodiment, the configuration in which the heat exchange between the low-concentration absorption liquid and the medium-concentration absorption liquid and the high-concentration absorption liquid is performed by one heat exchanger H is independent.
There is an advantage that piping can be simplified as compared with the case of using two heat exchangers.

FIG. 6 shows the temperature change of the absorbing liquid that is heat-exchanged in the heat exchanger H. The low-temperature low-concentration absorption liquid discharged from the absorber 3 is supplied to the heat exchanger H by the absorption liquid pump P1, is heat-exchanged with the high-concentration absorption liquid and the medium-concentration absorption liquid, and then heated. It is returned to 11, heated again and boiled.

The medium-concentration absorption liquid in the medium-concentration absorption liquid separation cylinder 12 has a high temperature, is heat-exchanged with the low-concentration absorption liquid in the heat exchanger H, is cooled, and then is supplied to the low-temperature regenerator by a pressure difference. To be done. The high-concentration absorption liquid generated in the low-temperature regenerator 2 is heat-exchanged with the low-concentration absorption liquid in the heat exchanger H to be cooled, and is supplied to the high-concentration absorption liquid sprayer 32 with a pressure difference.

As shown in FIG. 1, the high-concentration absorption liquid outlet 76 is an axial slit 8 so as to communicate with each high-concentration absorption liquid flow path formed between the plates 64, 64 as a throttle hole.
The outlet pipe 8 provided with 1 is formed so as to penetrate almost all the plates 64.

The slit 81 serves as a throttle hole 82 for a number of high-concentration absorbent liquid flow paths L4 provided in the heat exchanger H. The throttle hole 82 can prevent the pressure of the high-concentration absorbent or the medium-concentrated absorbent in the heat exchanger from decreasing. As a result, it is possible to prevent the occurrence of vapor lock due to the pressure reduction in the heat exchanger. The same effect can be obtained by applying the present invention to the medium-concentration absorption liquid outlet 74 in the medium-concentration absorption liquid heat exchanger.

That is, when the medium-concentration absorption liquid and the high-concentration absorption liquid that flow due to the pressure difference form a flow path from the bottom to the top in the heat exchanger H, the factor of the head difference is further added and the flow proceeds further downstream. The pressure is reduced and it becomes easier to boil. As in the present invention, the pressure on the upstream side of the outlet pipe 8 is maintained at a predetermined level or higher to prevent boiling due to the reduced pressure, and the absorption liquid is retained to maintain the liquid phase state, whereby the heat exchange rate can be further improved.

The slit 81 is formed in the upper end portion of the outlet pipe 8 so that the high-concentration absorption liquid is exposed to the high-concentration absorption liquid outlet 76.
When it flows out of the outlet pipe, it passes through the side of the outlet pipe 8 and turns upward. Therefore, the effect of the restriction is easily made uniform in the length direction of the slit, the flow becomes uniform, and the heat exchange efficiency can be further improved. The throttle hole 82 may be a row of holes formed corresponding to each high-concentration absorbent liquid flow path L4 in the heat exchanger H, but the use of the slit 81 reduces the labor of processing. Of course, other heat sources such as an electric heater can be used as the heating source.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a heat exchanger.

FIG. 2 is a front view of a heat exchanger.

FIG. 3 is a side view of the heat exchanger.

FIG. 4 is a perspective view of an absorption refrigeration system.

FIG. 5 is a configuration diagram of an absorption refrigeration system.

FIG. 6 is a graph showing a heat exchange action by a heat exchanger.

[Explanation of symbols]

 1 High Temperature Regenerator 2 Low Temperature Regenerator 3 Absorber 4 Evaporator 5 Condenser 6 Casing 8 Outlet Pipe 10 Refrigerant Recovery Tank 11 Heating Tank 64 Plate 71 Low Concentration Absorption Liquid Inlet 72 Low Concentration Absorption Liquid Inlet 73 Medium Concentration Absorption Liquid Inlet 74 Medium concentration absorption liquid outlet 75 High concentration absorption liquid inlet 76 High concentration absorption liquid outlet 81 Slit 82 Throttling hole 100 Absorption type refrigerator 200 Refrigerator body B Gas burner (heating source) H Heat exchanger L1 Medium concentration absorption liquid flow path L2 Low Concentrated absorbent flow path L4 Highly concentrated absorbent flow path

Continuation of the front page (72) Inventor Tsutomu Maruhashi 2-26 Fukuzumi-cho, Nakagawa-ku, Nagoya City Rinnai Co., Ltd. ) Inventor Norio Kaedo 4-1-2, Hirano-cho, Chuo-ku, Osaka, Osaka Gas Co., Ltd. (72) Inventor Kaoru Watanabe 2-49, Numame, Isehara, Kanagawa Prefecture

Claims (5)

[Claims] 1. A high-temperature regenerator having a heating source, a heating tank for boiling the low-concentration absorption liquid by the heating source to separate it into a refrigerant and a medium-concentration absorption liquid, and a refrigerant recovery tank for recovering the evaporated refrigerant. A low-temperature regenerator that re-boils the medium-concentration absorption liquid using the refrigerant recovery tank as a heat source to separate the refrigerant vapor and the high-concentration absorption liquid, and a condenser that condenses the refrigerant generated in the high-temperature regenerator and the low-temperature regenerator. And a refrigerator main body including an evaporator that evaporates the condensed refrigerant liquid to cool the cold / hot water for the cold heat source, and an absorber that absorbs the evaporated refrigerant vapor into the high-concentration absorption liquid, and the low temperature regenerator. The generated high-concentration absorption liquid is passed through a high-concentration absorption liquid heat exchanger to exchange heat with the low-concentration absorption liquid discharged from the absorber, and then a high-concentration absorption liquid flow path is introduced to the absorber. In the absorption type refrigeration equipment equipped with The high-concentration absorbent heat exchanger has a structure in which plates for partitioning the respective absorbent channels are stacked in a casing, and the high-concentration absorbent channel is a high-concentration absorbent under the casing. An inlet, having a high-concentration absorbent outlet at the upper level, the high-concentration absorbent outlet is an outlet pipe with a throttle hole that communicates with each high-concentration absorbent channel formed between the stacked plates in the casing. An absorption type refrigerating apparatus, which is formed by penetrating and inserting substantially all plates in a casing. 2. A high-temperature regenerator having a heating source, a heating tank for boiling the low-concentration absorption liquid by the heating source to separate it into a refrigerant and a medium-concentration absorption liquid, and a refrigerant recovery tank for recovering the evaporated refrigerant. A low-temperature regenerator that re-boils the medium-concentration absorption liquid using the refrigerant recovery tank as a heat source to separate the refrigerant vapor and the high-concentration absorption liquid, and a condenser that condenses the refrigerant generated in the high-temperature regenerator and the low-temperature regenerator. And a refrigerator main body including an evaporator that evaporates the condensed refrigerant liquid to cool the cold / hot water for the cold heat source, and an absorber that absorbs the evaporated refrigerant vapor into the high-concentration absorption liquid, and the low temperature regenerator. The high-concentration absorbent generated, after passing through a high-concentration absorbent heat exchanger to exchange heat with the low-concentration absorbent discharged from the absorber, a high-concentration absorbent flow path leading to the absorber, Medium concentration produced by the high temperature regenerator An absorption type having a medium-concentration absorption liquid flow path that guides the low-concentration absorption liquid discharged from the absorber after passing through the medium-concentration absorption liquid heat exchanger to the low-temperature regenerator. In the refrigeration system, the medium-concentration absorbent heat exchanger has a structure in which medium-concentration plates that partition the respective absorption liquid channels are stacked in a medium-concentration casing, and the medium-concentration absorbent liquid channel is The medium-concentration casing has a medium-concentration absorption liquid inlet at a lower level and an upper-level medium concentration absorption liquid outlet, and the medium-concentration absorption liquid outlets are formed at intermediate concentrations of the medium-concentration plates stacked in the medium-concentration casing. An outlet pipe with a throttle hole that communicates with the absorbing liquid flow path is formed by inserting substantially all of the medium concentration plate into the medium concentration casing, and the low concentration absorbing liquid discharged from the absorber is converted into the high concentration Absorption liquid heat exchanger and medium concentration Intermediate concentration absorption solution by Osamueki heat exchanger and the high concentration absorption solution and heat exchange, absorption refrigerating apparatus is characterized in that a low concentration absorption solution flow path for feeding back into the high-temperature regenerator. 3. The high-concentration absorption liquid heat exchanger and the medium-concentration absorption liquid heat exchanger according to claim 1 or 2, wherein the high-concentration absorption liquid heat exchanger and the medium-concentration absorption liquid heat exchanger are vertically arranged in the same vertically long casing. The channel has a low-concentration absorbent inlet at the upper end of the casing and a low-concentration absorbent outlet at the lower end, and is formed along the entire length of the casing, and the medium-concentration absorbent channel is at the lower end of the casing. A high concentration absorbent inlet is provided in the middle of the casing and a high concentration absorbent inlet is formed in the middle of the casing. An absorption type refrigerating apparatus having a concentrated absorbent outlet and formed from the middle to the upper end of the casing. 4. The absorption refrigerating device according to claim 1, wherein the throttle hole is an axial slit formed in the outlet pipe. 5. The absorption refrigeration system according to claim 1, wherein the throttle hole is formed in an upper portion of an outer peripheral surface of the outlet pipe.