JP2651239B2 - Double-effect air-cooled absorption refrigerator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a double-effect air-cooled absorption refrigerator,
The present invention relates to a double-effect air-cooled absorption refrigerator having a refrigerant piping system suitable for the return of a refrigerant flow path and the overflow function in a configuration in which the liquid level of an air-cooled condenser is located at a lower part of the entire apparatus.

[Prior Art] In a conventional water-cooled absorption refrigerator, the liquid level of the condenser is arranged higher than the liquid level of the evaporator, and the condensed refrigerant is returned to the evaporator by a position head.

For example, according to “Absorption refrigerator and its application” (edited by the Japan Refrigeration Association, published on October 20, 1972), P.33
55, Fig. 2 on page 45, Fig. 2 on page 60, and Fig. 2 on page 75, in all of the absorption refrigeration cycles, the condenser is installed at a higher position than the evaporator. Then, the condensed refrigerant from the condenser is returned to the evaporator by the position head.

[Problems to be Solved by the Invention] In the water-cooled absorption chiller, since the water is cooled by the cooling water of the cooling tower, installation work, maintenance, and water management are costly. It has been advanced.

For example, as an air-cooled absorption chiller using water as a refrigerant and lithium bromide as an absorbent, the technology described in JP-A-61-49970 has been developed, and the absorber and the condenser are cooled by the flow of air by fan. For this purpose, a vertical tube having a fin provided outside the tube is used.

By the way, when the liquid level of the air-cooled condenser is changed to the air-cooled type from the water-cooled type and the liquid level of the air-cooled condenser is in the lower part of the entire device, the condensed refrigerant flows to the evaporator due to the pressure difference between the air-cooled condenser and the evaporator in the operation at the specification point However, when the pressure difference is small, such as when the load is low or when starting, there is a problem that the condensed refrigerant cannot be returned to the evaporator.

When the load is high and the operation is higher than the rating (specification point), the solution may enter the crystal region due to the high concentration of the solution. At this time, the amount of the refrigerant in the evaporator exceeds the set point. However, the air-cooled absorption chiller has a problem that the refrigerant cannot be sent to the air-cooled absorber only by natural fall, and a means for overflowing the refrigerant is required, and the overflow does not function properly.

The present invention has been made in order to solve the above-described problems in the prior art, and when the liquid level of the air-cooled condenser is at a position lower than the liquid level of the evaporator, a refrigerant return system that returns the condensed refrigerant to the evaporator, and It is an object of the present invention to provide a double-effect air-cooling absorption refrigerator capable of optimally functioning a refrigerant piping system of a refrigerant overflow system.

[Means for Solving the Problems] In order to achieve the above object, a first invention of a double-effect air-cooled absorption refrigerator according to the present invention comprises an evaporator, an air-cooled absorber, an air-cooled condenser, and a low-temperature condenser. A regenerator, a high-temperature regenerator, a solution heat exchanger, a solution circulation pump, a refrigerant spray pump, and a piping system for operatively connecting these, the air-cooled absorber, and a fan for supplying cooling air to the air-cooled condenser In the double effect air-cooled absorption refrigerator, the evaporator is located higher than the air-cooled condenser in the middle of the refrigerant return pipe connecting the air-cooled condenser and the evaporator, and the liquid level of the air-cooled condenser and the evaporator liquid level And a weir means that overflows when the working fluid level becomes higher than a preset coolant level in the evaporator. From the weir means to the air-cooled absorber Alternatively, a refrigerant pipe for returning to the solution system is provided.

In addition, the second effect air-cooled absorption refrigerator of the present invention has a second effect.
The invention comprises an evaporator, an air-cooled absorber, an air-cooled condenser, a low-temperature regenerator, a high-temperature regenerator, a solution heat exchanger, a solution circulation pump, a refrigerant spray pump, and a piping system operatively connecting these. In the double-effect absorption refrigerator including a fan for supplying cooling air to the air-cooled absorber and the air-cooled condenser, the air-cooled condenser includes a refrigerant tank communicating with a refrigerant container of the evaporator. A liquid level switch is provided so as to maintain the liquid level at substantially the same level, a U-shaped tubular refrigerant return pipe connecting the air-cooled condenser and the refrigerant tank is provided, and a refrigerant spray pump connected to the refrigerant tank. And a refrigerant blow pipe branched from the refrigerant spray pipe and provided with an electromagnetic valve and connected to an air-cooled absorber or a part of the solution system. It is obtained so as to open and close the solenoid valve by.

Further, the configuration of the third invention of the double-effect air-cooled absorption refrigerator according to the present invention includes an evaporator, an air-cooled absorber, an air-cooled condenser,
It consists of a low-temperature regenerator, a high-temperature regenerator, a solution heat exchanger, a solution circulation pump, a refrigerant spray pump, and a piping system operatively connecting these, and the fan for supplying cooling air to the air-cooled absorber and air-cooled condenser. The double effect air-cooling absorption refrigerator includes a refrigerant tank that communicates with a refrigerant container of the evaporator, and the refrigerant tank includes a main refrigerant tank and an auxiliary refrigerant tank having a cross-sectional area smaller than the cross-sectional area of the main refrigerant tank. The auxiliary refrigerant tank is provided with a weir means that overflows when the refrigerant exceeds a set liquid level, and a refrigerant pipe connected from the weir means to the air-cooled absorber. The one having a U-shaped refrigerant return pipe arranged higher than the liquid level of the air-cooled absorber at the lowest concentration and connecting the air-cooled condenser and the refrigerant tank. A.

[Operation] The first invention is a technical means when the liquid level of the evaporator is higher than the liquid level of the air-cooled condenser and higher than the differential pressure liquid column head.

In this case, the return of the condensed refrigerant from the air-cooled condenser to the evaporator is performed by refrigerant supply means such as a refrigerant pump or a refrigerant ejector. Refrigerant overflow in the evaporator is performed by the opening weir and the refrigerant overflow pipe, and returns the refrigerant to the air-cooled absorber or the solution system.

The second invention is a technical means when the liquid level of the evaporator is equal to the liquid level of the air-cooled condenser.

In this case, the condensed refrigerant easily flows to the evaporator side refrigerant tank through the U-shaped tubular refrigerant return pipe. However, in order to flow the refrigerant overflow for avoiding crystallization to the air-cooled absorber at the same position as the air-cooled condenser (or to prevent the solution from flowing back to the piping system), it is necessary to use a refrigerant spray pump or the like. The refrigerant is returned to the air-cooled absorber or the solution system by the refrigerant blow pipe via the refrigerant supply means.

The third invention is a technical means in a case where the evaporator or the auxiliary refrigerant tank is located at an intermediate position between the first and second inventions.

In this case, the condensed refrigerant flows to the evaporator-side refrigerant tank by the U-shaped tubular refrigerant return pipe at the position head and the operating differential pressure during operation. In the refrigerant overflow, an opening weir for overflow is provided in the auxiliary refrigerant tank at a position higher than the maximum liquid level of the air-cooled absorber, and the refrigerant is returned to the air-cooled absorber or the solution system by the refrigerant overflow pipe.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a cycle diagram of a double-effect air-cooled absorption refrigerator according to one embodiment of the first invention.

In FIG. 1, 1 is an evaporator, 2 is an evaporator liquid level, 3 is an air-cooled condenser, 4 is an air-cooled condenser liquid level, and 5 is an air-cooled condenser 3
A refrigerant return pipe connecting the evaporator 1 and the evaporator 1, 6 is a refrigerant pump related to refrigerant supply means provided in the refrigerant return pipe 5, 7 is a bypass pipe, 8 is an orifice provided in a bypass pipe 7, 9 is , An open weir relating to overflow weir means provided in the refrigerant container of the evaporator 1,
Overflow pipe to 14; refrigerant spray pump 11; refrigerant spray pipe 12; air-cooled absorber 14; high-temperature regenerator 16; low-temperature regenerator 16; air-cooled condenser 3 and air-cooled absorber 14 A fan for supplying air, 25 is a cold water pipe passing through the evaporator 1, 26 is a steam passage connecting the evaporator 1 and the air-cooled absorber 14, 27 is a solution circulation pump, and 28 is an air-cooled absorber
Dilute solution piping connecting the solution container of 14 with the solution heat exchanger 29, 29
Is the solution heat exchanger, 30 is the solution heat exchanger 29 and the high-temperature regenerator 15
The dilute solution tube connecting the solution heat exchanger 29 and the low temperature regenerator
Dilute solution pipe connecting to 16, 32 is a refrigerant vapor pipe, 33 is a vapor passage,
34 is a concentrated solution pipe connecting the high temperature regenerator 15 and the solution heat exchanger 29, 35 is a concentrated solution pipe connecting the low temperature regenerator 16 and the solution heat exchanger 29, and 36 is a solution heat exchanger 29 and air cooling. This is a concentrated solution pipe connecting the absorber 14.

First, the operation of the basic cycle of such a double-effect air-cooled absorption refrigerator will be described.

The refrigerant (water) in the evaporator 1 is supplied to a refrigerant spray pump 11,
The refrigerant is sprayed on the cold water pipe 25 through which the cold water passes through the refrigerant spray pipe 12, takes away the heat of evaporation from the cold water, becomes low-pressure refrigerant vapor, and flows into the air-cooled absorber 14 via the vapor passage 26. The air-cooled absorber 14 is air-cooled by the fan 17, and the refrigerant vapor is scattered from above and absorbed by the lithium bromide concentrated solution flowing down the vertical tube to become a dilute solution.

The diluted solution is supplied to the diluted solution piping by the solution circulation pump 27.
28, and passed through the solution heat exchanger 29 to dilute solution tubes 30, 31
Are sent to the high-temperature regenerator 15 and the low-temperature regenerator 16 via the.

An external heat source is supplied to the high temperature regenerator 15, and the high temperature regenerator 15 concentrates the dilute solution by the heat of combustion of the furnace 15a to generate steam. The generated refrigerant vapor heats and concentrates the dilute solution in the low-temperature regenerator 16 via the heat transfer tube section 16a of the refrigerant vapor pipe 32.

The vapor generated from the dilute solution concentrated in the low-temperature regenerator 16 flows into the vertical pipe of the air-cooled condenser 3 through the vapor passage 33, is air-cooled by the fan 17, condensed and liquefied, becomes a liquid refrigerant, and becomes a liquid refrigerant. Evaporator 1 from container via refrigerant return pipe 5
Return to the refrigerant container.

The solutions concentrated in the high-temperature regenerator 15 and the low-temperature regenerator 16 respectively pass through the solution heat exchanger 29 by the concentrated solution pipes 34 and 35, and then are sent to the upper header of the air-cooled absorber 14 via the concentrated solution pipe 36 and dispersed. And the absorption process is repeated again.

Next, the features of this embodiment will be described in more detail.

During operation, the evaporator liquid level 2 is higher than the air-cooled condenser liquid level 4 by the operating pressure difference (for example, condenser 50 mmHg-evaporator 7 mmHg = 42 mmHg).
= 571mmAg) or higher. At the pressure difference between the two, the condensed refrigerant does not return from the air-cooled condenser 3 to the evaporator 1.

Therefore, in the embodiment of FIG. 1, a refrigerant pump 6 is provided in the refrigerant return pipe 5 as a refrigerant supply means having a capacity exceeding the working pressure liquid column height, and the condensed refrigerant is pumped from the air-cooled condenser 3 to the evaporator. I'm going back to 1.

In order to balance suction pressure of the refrigerant pump 6 and prevent cavitation, a bypass pipe 7 having an orifice 8 (or a throttle valve) is provided before and after the refrigerant pump 6.

On the other hand, when the concentration of the solution becomes high and the refrigerant is abnormally separated, the refrigerant overflows through the opening weir 9 formed in the refrigerant container of the evaporator 1, and the refrigerant flows into the solution of the air-cooled absorber 14 via the overflow pipe 10. Dilute the solution flowing into the container.

According to the embodiment of FIG. 1, the liquid refrigerant flows from the air-cooled condenser 3 to the evaporator 1 even when the evaporator liquid level 2 is higher than the air-cooled condenser liquid level 4 and higher than the differential pressure liquid column head. It is possible to reliably return the refrigerant, and to make the refrigerant overflow in the evaporator 1 function properly, so that the double-effect air-cooled absorption refrigerator can be safely operated.

In the embodiment shown in FIG. 1, an example has been described in which all the overflowed refrigerant is sent to the air-cooled absorber. However, the refrigerant may be returned to another solution system to dilute the solution.

Next, FIG. 2 is a cycle diagram of a double-effect air-cooling absorption refrigerator according to another embodiment of the first invention. In FIG. 2, the same reference numerals as those in FIG. 1 denote the same parts, and a description thereof will be omitted.

2 differs from the embodiment of FIG. 1 in that the refrigerant supply means includes a refrigerant return pipe 5A from the air-cooled condenser 3 and a refrigerant spray pump 11 of a refrigerant spray pipe 12.
Is connected via a refrigerant ejector 13 to the discharge side of the.

According to the embodiment of FIG. 2, the condensed refrigerant is a refrigerant ejector.
The evaporator 1 is operated via the refrigerant spray pipe 12 by the operation of 13.
The same effect as that described in the embodiment of FIG. 1 can be expected.

Next, FIG. 3 is a cycle system diagram of a double effect air-cooled absorption refrigerator according to one embodiment of the second invention. In FIG. 3, the same reference numerals as those in FIG. 1 denote the same parts, and a description thereof will be omitted.

In FIG. 3, reference numeral 18 denotes a refrigerant tank which communicates with the refrigerant container of the evaporator 1. The refrigerant liquid level 2 '(corresponding to the evaporator liquid level) in this refrigerant tank is substantially the same as the air-cooled condenser liquid level 4. It is provided at a position that can be maintained at the level. 19 is an air-cooled absorber liquid level, 20 is a liquid-level switch for controlling the refrigerant liquid level 2 'to the same level as the air-cooled condenser liquid level 4, 21 is an electromagnetic valve, and 23 is an electromagnetic valve branched from the refrigerant spray pipe 12B. This is a refrigerant blowpipe provided with a valve 21 and connected to the air-cooled absorber 14.

In the double effect air-cooled absorption refrigerator shown in FIG. 3, when the operation is started, the condensed refrigerant collects in the refrigerant container of the air-cooled condenser 2, the liquid level rises, and the refrigerant tank passes through the refrigerant U-shaped refrigerant return pipe 5B. Return to 18. Further, a differential pressure is generated by the operation, and the pressure also returns by the pressure.

On the other hand, the liquid level 19 of the air-cooled absorber is almost the same level. Therefore, if the overflow pipe is provided from the liquid level of the refrigerant in the refrigerant tank, the solution flows backward and the refrigerant is contaminated.

Therefore, a liquid level switch 20 is provided as a liquid level sensor at the refrigerant liquid level 2 '(set liquid level) of the refrigerant tank 18.

When the refrigerant liquid level 2 'rises, the solenoid valve 21 is opened by the signal of the liquid level switch 20, and the power of the refrigerant spray pump 11 causes
Refrigerant blow pipe 23 from a high position where there is no concern about backflow of the solution
The refrigerant flows to the air-cooled absorber 14 via to dilute the solution.

According to the embodiment of FIG. 3, even when the refrigerant liquid level 2 'of the refrigerant tank 18 corresponding to the evaporator liquid level is at the same level as the air-cooled condenser liquid level 4, the liquid refrigerant is supplied from the air-cooled condenser 3 to the evaporator. In addition to being able to reliably return the refrigerant to the refrigerant tank 18 on the first side, the refrigerant that exceeds the set refrigerant level is reliably sent to the air-cooled absorber 14 without backflow of the solution, and fulfills the refrigerant overflow function. Can be safely driven.

Next, FIG. 4 is a cycle diagram of a double-effect air-cooled absorption refrigerator according to one embodiment of the third invention. In the drawings, those having the same reference numerals as those in FIGS. 1 and 3 are the same parts as those of the embodiments, and the description thereof will be omitted.

In the embodiment of FIG. 4, the refrigerant liquid level of the operating refrigerant tank is located between the evaporator liquid level 2 of FIG. 1 and the refrigerant liquid level 2 ′ of the refrigerant tank of FIG. It is.

In FIG. 4, reference numeral 18 'denotes a refrigerant tank which communicates with the refrigerant container of the evaporator 1. This refrigerant tank 18' is composed of a main refrigerant tank and an auxiliary refrigerant tank 18a having a smaller sectional area than that of the main refrigerant tank. It is formed integrally. The refrigerant liquid level 2 ″ in the auxiliary refrigerant tank 18a is at a level higher by HmmAg than the air-cooled condenser liquid level 4.

When the load is low, the refrigerant liquid level of the refrigerant tank 18 ′ is substantially the same as the liquid level of the air-cooled condenser 14, and when the load is high, the refrigerant liquid level is higher at the upper part of the main refrigerant tank. An auxiliary refrigerant tank 18a having a small sectional area is formed.

9A is an open weir provided in the auxiliary refrigerant tank 18a.
A is a weir means that overflows when the refrigerant exceeds the set liquid level. 10A is an overflow pipe connected from the opening weir 9A to the air-cooled absorber 14. The opening weir 9A is arranged higher than the liquid level 19 of the air-cooled absorber at the lowest concentration of the solution, that is, the maximum liquid level of the air-cooled absorber 14.

In the double-effect air-cooled absorption refrigerator shown in FIG.
As described above, the liquid level 4 of the air-cooled condenser is lower than the refrigerant level 2 ″ of the auxiliary refrigerant tank by HmmAg. Therefore, when the pressure difference between the two sections during operation exceeds H / 13.6mmHg, the condensed refrigerant is not generated until the liquid level increases. The air flows from the air-cooled condenser 3 to the refrigerant tank 18 'via the U-shaped refrigerant return pipe 5B (for example, if H = 200 mmAg, the pressure difference is 14.7 mmHg).
Until the refrigerant flows into the air-cooled condenser 3, the refrigerant accumulates in the refrigerant container of the air-cooled condenser 3 and the liquid level rises.

In case of abnormal separation of the refrigerant, the auxiliary refrigerant tank 18
The refrigerant overflows from the opening weir 9A provided in a, and the refrigerant is returned to the air-cooled absorber 14 via the overflow pipe 10A to dilute the solution. At this time, as described above, the opening weir 9A
Is arranged higher than the maximum liquid level of the absorber, so that the refrigerant is not contaminated by the backflow of the solution.

Next, FIG. 5 is a cycle system diagram of a double-effect air-cooled absorption refrigerator according to still another embodiment of the first invention.
In the figure, components having the same reference numerals as those of FIG. 1 are the same as those of the embodiment of FIG. 1, and the description thereof will be omitted.

5 is different from the embodiment of FIG. 1 in that the cavitation of the refrigerant pump 6 is prevented by the bypass pipe in the embodiment of FIG. A liquid level switch 22 is provided in the refrigerant container,
A flow control valve 24 interlocked with the liquid level switch 22 is provided on the refrigerant return pipe 5C discharge side of the refrigerant return pipe 5C.
Of circulating air to prevent cavitation.

That is, if the liquid level of the air-cooled condenser 4 drops, cavitation may occur in the refrigerant pump 6. Therefore, the liquid level is detected by the liquid level switch 22, and when the liquid level is lowered, the flow control valve 24 is opened. The refrigerant circulation amount is controlled with a small degree.

According to the embodiment of FIG. 5, the same effect as that described in FIG. 1 is expected.

[Effects of the Invention] As described above, according to the present invention, when the liquid level of the air-cooled condenser is lower than the liquid level of the evaporator, the refrigerant return system for returning the condensed refrigerant to the evaporator, and the refrigerant overflow It is possible to provide a double-effect air-cooled absorption refrigerator capable of optimally functioning a system refrigerant piping system.

[Brief description of the drawings]

FIG. 1 is a cycle system diagram of a double-effect air-cooled absorption refrigerator according to one embodiment of the first invention, and FIG. 2 is a double-effect air-cooled absorption refrigerator according to another embodiment of the first invention. FIG. 3 is a cycle system diagram of a refrigerator, FIG. 3 is a cycle system diagram of a double-effect air-cooled absorption refrigerator according to one embodiment of the second invention, and FIG.
FIG. 5 is a cycle diagram of a double-effect air-cooled absorption refrigerator according to an embodiment of the present invention. FIG. 5 is a cycle diagram of a double-effect air-cooled absorption refrigerator according to still another embodiment of the first invention. It is. 1 ... evaporator, 2 ... evaporator liquid level, 2 ', 2 "... refrigerant liquid level, 3 ... air-cooled condenser, 4 ... air-cooled condenser liquid level, 5,5A, 5
C: refrigerant return line, 5B, U-shaped refrigerant return line, 6
... refrigerant pump, 7 ... bypass pipe, 8 ... orifice, 9, 9A ... open weir, 10, 10A ... overflow pipe,
11 ... refrigerant spray pump, 12, 12B ... refrigerant spray pipe, 13 ... refrigerant ejector, 14 ... air-cooled absorber, 15 ...
High temperature regenerator, 16 …… Low temperature regenerator, 17 …… Juan, 18,1
8 ': refrigerant tank, 18a: auxiliary refrigerant tank, 19: air-cooled absorber liquid level, 20, 22, liquid level switch, 23: refrigerant blow pipe, 24: flow control valve, 27: solution Circulation pump,
29 …… Solution heat exchanger.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeyoshi Kurosawa 2-26 Kanamecho, Toshima-ku, Tokyo (72) Inventor Yoshikazu Nagaoka 5-22-4 Kami-Soshigaya Heights 302, Kami-Soshigaya Heights 302 (72) Inventor Shinichi Kanou 4-9-1-4-303 Takawashi, Habikino-shi, Osaka (72) Inventor Sadatoshi Takemoto 11-8, Tonencho, Chigusa-ku, Nagoya, Aichi Prefecture 603 Hitachi, Ltd. Tsuchiura Plant (72) Inventor Tomohisa Ouchi 502, Kunitachi-cho, Tsuchiura-shi, Ibaraki Pref. Hitachi, Ltd. Machinery Research Institute (56) References JP-A-2-50058 (JP, A) Hei 1-63965 (JP, U)

Claims (6)

(57) [Claims] An evaporator, an air-cooled absorber, an air-cooled condenser, a low-temperature regenerator, a high-temperature regenerator, a solution heat exchanger, a solution circulation pump, a refrigerant spray pump, and a piping system for operatively connecting these, In the double-effect air-cooled absorption refrigerator having a fan for supplying cooling air to the air-cooled absorber and the air-cooled condenser, in the middle of a refrigerant return pipe connecting the air-cooled condenser and the evaporator, the evaporator has an air-cooled condenser. A refrigerant supply means is provided when the height difference between the liquid level of the air-cooled condenser and the liquid level of the evaporator exceeds the differential pressure liquid column height, and is set in advance in the evaporator. A double-effect air-cooled absorption refrigerator comprising: a weir means that overflows when the working fluid level becomes higher than the refrigerant fluid level, and a refrigerant pipe returning from the weir means to an air-cooled absorber or a solution system. 2. The refrigerant supply device according to claim 1, wherein the refrigerant supply means includes a refrigerant pump in a refrigerant return pipe connecting the air-cooled condenser and the evaporator. A double-effect air-cooled absorption refrigerator comprising a bypass pipe provided with an orifice. 3. The refrigerant supply means according to claim 1, wherein the refrigerant supply means connects a refrigerant return pipe from the air-cooled condenser to a refrigerant spray pump discharge side of the refrigerant spray pipe via a refrigerant ejector. A double-effect air-cooled absorption refrigerator. 4. A liquid level switch is provided in a refrigerant liquid container of an air-cooled condenser according to claim 1, and said liquid level switch is provided on a refrigerant pump discharge side of a refrigerant return pipe from said air-cooled condenser. A double-effect air-cooled absorption chiller characterized by having a flow control valve interlocked with the chiller. 5. An evaporator, an air-cooled absorber, an air-cooled condenser, a low-temperature regenerator, a high-temperature regenerator, a solution heat exchanger, a solution circulation pump, a refrigerant spray pump, and a piping system for operatively connecting these, The air-cooled absorber, a double-effect air-cooled absorption refrigerator including a fan for supplying cooling air to the air-cooled condenser, includes a refrigerant tank communicating with a refrigerant container of the evaporator, and the refrigerant liquid level of the air-cooled condenser. A liquid level switch is provided so as to maintain the liquid level at substantially the same level, a U-shaped tubular refrigerant return pipe connecting the air-cooled condenser and the refrigerant tank is provided, and a refrigerant spray pump connected to the refrigerant tank. And a refrigerant blow pipe branched from the refrigerant spray pipe and provided with an electromagnetic valve and connected to an air-cooled absorber or a part of the solution system. Double-effect air-cooled absorption type refrigerating machine, characterized in that so as to open and close the solenoid valve by. 6. An evaporator, an air-cooled absorber, an air-cooled condenser, a low-temperature regenerator, a high-temperature regenerator, a solution heat exchanger, a solution circulation pump, a refrigerant spray pump, and a piping system for operatively connecting these. The air-cooled absorber, the double-effect air-cooled absorption refrigerator having a fan for supplying cooling air to the air-cooled condenser, a refrigerant tank communicating with a refrigerant container of an evaporator, the refrigerant tank is a main refrigerant tank and An auxiliary refrigerant tank having a cross-sectional area smaller than that of the main refrigerant tank is formed integrally with the auxiliary refrigerant tank, and the auxiliary refrigerant tank has a weir means that overflows when the refrigerant exceeds a set liquid level, and an air-cooled absorber from the weir means. And an overflow weir is disposed higher than the liquid level of the air-cooled absorber at the lowest concentration of the solution, and the air-cooled condenser and the refrigerant tank Double-effect air-cooled absorption type refrigerating machine, characterized in that a U-shaped refrigerant return pipe connecting the.