JP3167491B2 - Absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller, and more particularly to an absorption chiller of a type in which the start / stop of a heat source side device is controlled by the start / stop of an indoor device.

[0002]

2. Description of the Related Art In a conventional absorption refrigerator, when the operation is stopped, a heat source side device is stopped prior to a secondary side device such as a fan coil. By this operation, the evaporator is supplied with the cold water whose temperature has risen due to heat exchange in the secondary device to the end, so that the evaporation of the refrigerant in the evaporator is not hindered to the end. For this reason, in the absorber, absorption of the refrigerant by the absorbing liquid proceeds, and dilution is performed by circulating the absorbing liquid, thereby preventing crystallization of the absorbing liquid after stopping.

However, in recent years, for the purpose of improving air conditioning, the start / stop of the heat source side device is not started / stopped mainly by the heat source side device but is started / stopped from the indoor side, that is, the air conditioner terminal side. There is an increasing demand in the market for controlled absorption chillers.

However, when the secondary device is stopped before the heat source device, the cold water flows back to the evaporator at a low temperature while maintaining a low temperature, so that the chilled water system is further cooled even if the evaporation amount of the refrigerant decreases. As a result, not only does the cooling water become supercooled when this state progresses, but also there is a problem that the refrigerant in the evaporator freezes.If the cooling water pump is stopped to avoid this state, it will be absorbed this time. This causes a problem that the flow of the absorbing solution is obstructed and the absorbing solution cannot be diluted because the pressure of the vessel and the condenser increases.

As described above, when the heat-source-side device follows the start / stop of the secondary-side device, the chilled water is not supercooled when the refrigeration load is rapidly reduced, and the refrigerant is not frozen. There is a need. For this purpose, it is necessary to quickly reduce the refrigerating capacity after stopping the secondary device, and it is also necessary to rapidly reduce the concentration difference energy obtained by concentrating the absorbing solution. If this is solved, it is possible to greatly reduce the conventionally required dilution operation time.

[0006] In order to prevent the supercooling of the cold water and the freezing of the refrigerant, a temperature corresponding to the cold water or the refrigerant is set in advance, and when the temperature of the cold water or the refrigerant decreases to this temperature, the heat source side device (high temperature regenerator). ) Or stop the absorption liquid pump,
Measures were taken to stop the operation of the cooling water pump. However, with this measure alone, the high-concentration absorbing liquid that had been created to maintain the refrigeration capacity remains as it is, so when the cooling water pump is started again, the cold water will be supercooled again, and the refrigerant will freeze. Or the absorption liquid crystallized.

On the other hand, as a technique for diluting the absorbing liquid in a short time, the refrigerant storage chamber and the concentrated liquid pipe on the inlet side of the low-temperature heat exchanger are connected to each other via an on-off valve, and the dilution operation during stoppage is performed. Or, when the cooling water temperature falls below a certain set temperature,
There is a type in which a refrigerant is press-fitted into a concentrated liquid pipe using a pressure of a high-temperature regenerator to be diluted. However, in this method, since the refrigerant and the absorbing liquid having a remarkably large concentration difference are mixed violently in the concentrated liquid pipe, not only a large mixing noise is generated, but also the piping system may be damaged due to vibration generated during mixing. There was a problem that there was.

[0008]

That is, a method in which the start / stop of the heat source side device can be controlled by the start / stop from the indoor side, that is, the air conditioner terminal side, and the secondary side device suddenly stops. Even if the refrigeration load suddenly decreases, the development of an absorption refrigerator that can dilute the absorption liquid even when the temperature of the chilled water is low without supercooling the chilled water or freezing the refrigerant has been an issue. Was.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and includes an absorber, an evaporator, a condenser, a high-temperature regenerator, a low-temperature regenerator, a low-temperature heat exchanger, In a double-effect absorption refrigerator that connects a high-temperature heat exchanger and an absorption liquid pump to form a circulation cycle of refrigerant and absorption liquid, the discharge-side piping of the absorption liquid pump and the low-temperature regenerator to the low-temperature heat exchanger At least one of the concentrated liquid pipe and the intermediate liquid pipe from the high-temperature regenerator to the high-temperature heat exchanger is provided with a normally closed on-off valve, and the diluted liquid discharge port is opened in the liquid flow direction of the inflow-side pipe. An absorption refrigerator, which is connected so as to be able to communicate via a branch pipe and is provided with a controller that opens the on-off valve when the operation of the absorption refrigerator is stopped,

[0010] A double connection in which an absorber, an evaporator, a condenser, a high-temperature regenerator, a low-temperature regenerator, a low-temperature heat exchanger, a high-temperature heat exchanger and an absorbent pump are connected by piping to form a circulation cycle of the refrigerant and the absorbent. In a utility absorption refrigerator, a normally closed on-off valve is interposed between the discharge pipe of the absorption pump and the concentrated pipe from the low-temperature regenerator to the low-temperature heat exchanger, and the diluted liquid discharge port is connected to the inflow pipe. Connected communicably via a branch pipe that opens in the liquid flow direction, and when at least one of the chilled water temperature, the chilled water temperature, or the refrigerant temperature in the evaporator drops to a predetermined temperature, the on-off valve is opened. An object of the present invention is to solve the above-mentioned problem of the related art by providing an absorption refrigerator having a controller provided.

[0011]

When the operation of the absorption refrigerator is stopped, when the temperature of the cold water drops to a predetermined temperature, when the temperature of the cooling water drops to a predetermined temperature, or when the temperature of the refrigerant in the evaporator drops to a predetermined temperature, The on-off valve of the branch pipe whose diluent discharge port opens in the liquid flow direction of the inflow side pipe is opened, and the dilute liquid is pumped by the absorbent pump to the concentrated liquid pipe from the low-temperature regenerator to the low-temperature heat exchanger and / or. Since the liquid is supplied to the intermediate liquid pipe from the high temperature regenerator to the high temperature heat exchanger, the concentrated liquid in the concentrated liquid pipe and the intermediate liquid in the intermediate liquid pipe are diluted in a short time. For this reason, the refrigerating capacity is quickly reduced and the pressure of the evaporator is increased, so that the cooling water is not overcooled or the refrigerant is not frozen.

[0012]

(Embodiment 1) A first embodiment will be described with reference to FIG.
A high-temperature regenerator that includes a combustion device 2 such as kerosene and generates a refrigerant vapor by heating a dilute liquid and concentrates the intermediate liquid into an intermediate liquid. A high-temperature regenerator 3 separates the refrigerant vapor pumped from the regenerator and the intermediate liquid. , A low-temperature regenerator that heats the intermediate liquid with the refrigerant vapor from the separator to make it a concentrated liquid, 5 a condenser that cools and condenses the refrigerant vapor from both the regenerators 1 and 4, and 6 a condenser An evaporator 7 for spraying and dropping the refrigerant liquid from the refrigerant distributor 30 to evaporate the refrigerant. An absorption unit 7 absorbs the refrigerant vapor from the evaporator into the concentrated liquid from the low-temperature regenerator 4 to maintain the inside of the container at a low pressure. 8 is a bubble pump for pumping the unevaporated refrigerant in the evaporator 6 with the residual heat of the refrigerant after heating the intermediate liquid in the low-temperature regenerator 4; 9 and 10 are low- and high-temperature heat exchangers; Liquid pipe 11, intermediate liquid pipe 12, concentrated liquid pipe 1
3, diluent pipe 15 having absorbent pump 14, refrigerant pipe 1
6, connected by a refrigerant liquid pipe 17 and a refrigerant return pipe 18 to form a circulation cycle of the refrigerant and the absorbing liquid,

Further, a branch pipe 22 having a normally closed on-off valve 19 allows communication between the inflow side of the dilute tube 15 into the low-temperature heat exchanger 9 and the inflow side of the concentrated tube 13 into the low-temperature heat exchanger 9. And a branch pipe 2 having a normally closed on-off valve 20
3 connects the inflow side of the diluent tube 15 to the low-temperature heat exchanger 9 and the inflow side of the intermediate liquid tube 12 to the high-temperature heat exchanger 10 while allowing the refrigerant reservoir 24 of the evaporator 6 to communicate. And the absorber 7 are communicably connected via a refrigerant blow pipe 25 having a normally closed on-off valve 21.

As shown in FIG. 5, the branch pipe 22 and the concentrated liquid pipe 13 or the branch pipe 23 and the intermediate liquid pipe 12 are connected to the open end of the branched pipe inside the concentrated liquid pipe 13 or the intermediate liquid pipe 12. And the opening is formed in the concentrated liquid pipe 13 or the intermediate liquid pipe 12.
It is installed in accordance with the flow direction of the absorbing liquid flowing through.

In particular, by forming the opening end portion to be narrowed as shown in (b), a still higher pressure can be applied, so that the absorption liquid can be circulated smoothly, and the intermediate liquid or the concentrated liquid can be concentrated. The effect of diluting the liquid is further enhanced.

Reference numeral 26 denotes a cooling water pipe connected through the interior of the evaporator 6, 27 denotes a cooling water pump, and a cooling water pipe connected via the interior of the absorber 7 and the condenser 5;
When the main body of the absorption chiller receives the operation stop signal, the operation of the cooling water pump 28 is stopped, and
The controller is provided so as to open 0.21 and stop the operation of the absorbent pump 14 with a delay of a predetermined time.

The order and timing of opening the on-off valves 19, 20 and 21 and the timing of stopping the operation of the absorbent pump 14 can be appropriately set by the controller 29.

In the absorption refrigerator having the above-mentioned structure, when the operation of the secondary side (not shown) is stopped and the refrigerating load is suddenly reduced, the refrigerant is returned to the evaporator 6 through the cold water pipe 26. The temperature of the chilled water continues to drop and drops to a temperature close to the evaporation temperature. For this reason, the operation stop of the absorption chiller body is instructed, and the control signal transmitted by the controller 29 stops the operation of the cooling water pump 28 to stop the cooling operation, and the on-off valves 19, 20, and 21. Are simultaneously opened, for example, and the refrigerant in the refrigerant reservoir 24 flows into the absorber 7 via the refrigerant blow pipe 25 and the on-off valve 21 to quickly dilute the absorbed liquid, and the diluted absorbed liquid is supplied to the absorbent pump. By the pump pressure 14, the concentrated liquid 13 is press-fitted into the low-temperature heat exchanger 9 on the inlet side through the branch pipe 22 and the on-off valve 19 to dilute the concentrated liquid in this part. Then, the intermediate liquid is press-fitted into the intermediate liquid pipe 12 at the inlet side of the high-temperature heat exchanger 10 to quickly dilute the intermediate liquid in this portion. Therefore, the concentration of the absorbing solution in the entire apparatus is rapidly reduced, the dilution time can be shortened, the crystallization of the absorbing solution can be avoided, and the absorber 7 significantly reduces the concentration of the absorbing solution to absorb the refrigerant. The cooling capacity of the evaporator 6 is suppressed, and the evaporation of the refrigerant in the evaporator 6 is suppressed, so that the cooling water in the chilled water pipe 26 is overcooled or the refrigerant is frozen.

(Embodiment 2) A second embodiment will be described with reference to FIG. This embodiment is different from the absorption refrigerator of the first embodiment in that a temperature detector 31 is provided.
Is installed so that the temperature of the refrigerant in the evaporator 6 can be detected, and the operation of the combustion device 2 can be controlled by the controller 29. The devices having the same functions as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted to the extent that the understanding of the first embodiment is not hindered.

When the temperature of the refrigerant flowing through the refrigerant distributor 30 detected by the temperature detector 31 decreases to a predetermined temperature (for example, 2 ° C.), the controller 29 in this embodiment controls the cooling water pump 28 Since the operation of the combustion device 2 is stopped and the on-off valves 19, 20, and 21 are provided to be simultaneously opened, for example, when the refrigerant temperature decreases to a predetermined temperature during the operation, the refrigerant is discharged in the same manner as in the first embodiment. Reservoir 24
Flows into the absorber 7 to quickly dilute the absorbing liquid, and the diluted absorbing liquid is pumped by the absorbing liquid pump 14 through the branch pipe 22 and the on-off valve 19 to form the concentrated liquid pipe 1.
3 is press-fitted into the inlet side of the low-temperature heat exchanger 9 to dilute the concentrated liquid in this portion.
The intermediate liquid in this portion is rapidly diluted by being press-fitted into the inlet side of the high-temperature heat exchanger 10 of No. 2. Therefore, in the absorber 7, the absorption liquid concentration is significantly reduced, and the ability to absorb the refrigerant is reduced,
Since the evaporation of the refrigerant in the evaporator 6 is suppressed, it is possible to prevent the chilled water in the chilled water pipe 26 from being supercooled or the refrigerant from being frozen.

When the temperature detector 31 detects a decrease in the refrigerant temperature in the evaporator 6, even if the operation of the cooling water pump 28 is stopped, the circulation of the cooling water supplied through the cooling water pipe 26 must be stopped. Because there is no, there is no hindrance to cooling operation.

(Embodiment 3) A third embodiment will be described with reference to FIG. The absorption chiller exemplified here is capable of detecting the chilled water temperature after heat exchange of the temperature detector 32 with the evaporator 6 instead of the temperature detector 31 in the absorption chiller shown in FIG. This is installed at the outlet from the evaporator 6. Also in this case, the devices having the same functions as those of the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted to the extent that the understanding of the embodiments is not hindered.

In the absorption refrigerator having the above structure, the temperature of the chilled water detected by the temperature detector 32 is set to a predetermined temperature (for example, 3
° C), the controller 29 transmits a control signal similar to that transmitted by the controller 29 when the temperature detector 31 detects a predetermined temperature in the second embodiment. Therefore, when the temperature of the chilled water drops to a predetermined temperature, the operation of the cooling water pump 28 and the combustion device 2 is stopped, and the on-off valves 19, 20, and 21 are opened to dilute the absorbent in the absorber 7, and the diluted absorption The liquid is the inlet of the low temperature heat exchanger 9 of the concentrated liquid tube 13 and the high temperature heat exchanger 1 of the intermediate liquid tube 12.
It is press-fitted to the inlet side of 0 to dilute the concentrated liquid and intermediate liquid in this part. Therefore, as in the case of the first and second embodiments,
In the absorber 7, the absorption liquid concentration is greatly reduced and the ability to absorb the refrigerant is reduced, and the evaporation of the refrigerant in the evaporator 6 is suppressed. Therefore, the chilled water in the chilled water pipe 26 becomes supercooled or the refrigerant is frozen. That is avoided.

(Embodiment 4) A fourth embodiment will be described with reference to FIG. The absorption chiller exemplified here uses a temperature detector 33 instead of the temperature detector 31 in the absorption chiller shown in FIG. 2 so that the temperature of the cooling water flowing into the absorber 7 can be detected. It is provided at the inlet of the absorber 7. Also in this case, the same reference numerals are given to the devices having the same functions as those in the first embodiment and the like, and the description thereof is omitted without impairing the understanding of the embodiments.

In the absorption refrigerator having the above configuration, the cooling water temperature detected by the temperature detector 33 is equal to a predetermined temperature (for example, 2
When the temperature is lowered to 6 ° C.), the controller 29 is provided so as to transmit a control signal similar to that transmitted by the controller 29 when the absorption refrigerator is stopped in the first embodiment. Is lowered to a predetermined temperature, the operation of the cooling water pump 28 is stopped, and the on-off valves 19, 20, and 21 are opened to dilute the absorbent in the absorber 7, and the diluted absorbent is cooled to a low temperature in the concentrated pipe 13. It is press-fitted into the heat exchanger 9 inlet side and the high temperature heat exchanger 10 inlet side of the intermediate liquid pipe 12 to dilute the concentrated liquid and the intermediate liquid in this portion. Therefore, as in the case of the first, second and third embodiments, in the absorber 7, the absorption liquid concentration is greatly reduced, and the ability to absorb the refrigerant is reduced.
The evaporation of the refrigerant in the cooling water pipe 26 is suppressed.
It is avoided that the cold water becomes supercooled or the refrigerant freezes.

Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the spirit of the appended claims.

For example, the absorbent pump 14 and the branch pipe 22.
A check valve 34 is installed in the diluent pipe 15 between the suction pipe 23 and the suction pipe to prevent the concentrated liquid from flowing into the absorber 7 when the operation of the absorbent pump is stopped, or a check valve 35 is installed in the branch pipe 23. Thus, it is possible to prevent the concentrated liquid from flowing into the intermediate liquid.

Further, the temperature detector 31 may be installed so as to detect the temperature of the refrigerant in the refrigerant reservoir 24, and the temperature detector 32 may be the temperature of the cold water flowing into the evaporator 6 or the temperature of the evaporator 6. It is also possible to install it at the inlet or inside the evaporator 6 so as to detect the temperature of the cooled cold water.

A temperature detector 3 for detecting the temperature of the refrigerant
1, two or three temperature detectors 32 for detecting the temperature of the cooling water, and two or three temperature detectors 33 for detecting the temperature of the cooling water are installed at the same time. It is also possible that the controller 29 stops the cooling water pump 28 and opens the on-off valves 19, 20, and 21.

An absorption refrigerator having only one of the branch pipes 22 and 23 may be provided.

It is also possible to use a normal refrigerant pump instead of the bubble pump 8 or an absorption refrigerator having no separator 3.

[0032]

As described above, the absorption refrigerator according to the present invention comprises an absorber, an evaporator, a condenser, a high-temperature regenerator, a low-temperature regenerator, a low-temperature heat exchanger, a high-temperature heat exchanger and an absorbent pump. In a double-effect absorption refrigerator that connects the pipes to form a circulation cycle of the refrigerant and the absorption liquid, the piping on the discharge side of the absorption pump, the concentrated liquid piping from the low-temperature regenerator to the low-temperature heat exchanger, and the high-temperature regenerator At least one of the intermediate liquid pipes leading to the heat exchanger is connected to be able to communicate via a branch pipe with a normally closed on-off valve and a dilute liquid discharge port opened in the liquid flow direction of the inflow side pipe. And an absorption refrigerator characterized by having a controller that opens the on-off valve when the operation of the absorption refrigerator is stopped,

[0033] Duplexing which connects the absorber, evaporator, condenser, high-temperature regenerator, low-temperature regenerator, low-temperature heat exchanger, high-temperature heat exchanger and absorbent pump to form a circulation cycle of refrigerant and absorbent. In a utility absorption refrigerator, a normally closed on-off valve is interposed between the discharge pipe of the absorption pump and the concentrated pipe from the low-temperature regenerator to the low-temperature heat exchanger, and the diluted liquid discharge port is connected to the inflow pipe. Connected communicably via a branch pipe that opens in the liquid flow direction, and when at least one of the chilled water temperature, the chilled water temperature, or the refrigerant temperature in the evaporator drops to a predetermined temperature, the on-off valve is opened. Since it is an absorption refrigerator characterized by having a controller that performs

When the operation of the absorption refrigerator is stopped, when the temperature of the cooling water drops to a predetermined temperature, when the temperature of the cooling water drops to a predetermined temperature, or when the temperature of the refrigerant in the evaporator drops to a predetermined temperature, The on / off valve of the branch pipe is opened and the diluted liquid is supplied to the concentrated liquid pipe from the low-temperature regenerator to the low-temperature heat exchanger and / or the intermediate liquid pipe from the high-temperature regenerator to the high-temperature heat exchanger by the absorbing liquid pump. The concentrated liquid in the concentrated liquid tube and the intermediate liquid in the intermediate liquid tube are diluted in a short time. For this reason, the refrigerating capacity is quickly reduced and the pressure of the evaporator is increased, so that the cooling water is not overcooled or the refrigerant is not frozen. Further, since there is no mixing of the refrigerant and the absorbing liquid having a remarkably large concentration difference, there is no fear of generating a loud noise or vibration. Furthermore, even when the temperature of the chilled water is reduced, the concentration of the absorbing solution in the entire apparatus can be rapidly reduced, and as a result, the absorbing solution can be reliably diluted even when the temperature of the chilled water is reduced. Is played.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment.

FIG. 2 is an explanatory diagram of a second embodiment.

FIG. 3 is an explanatory diagram of a third embodiment.

FIG. 4 is an explanatory diagram of a fourth embodiment.

FIG. 5 is an explanatory diagram of piping of a branch pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Combustion apparatus 3 Separator 4 Low temperature regenerator 5 Condenser 6 Evaporator 7 Absorber 8 Bubble pump 9 Low temperature heat exchanger 10 High temperature heat exchanger 11 Pumping pipe 12 Intermediate liquid pipe 13 Concentrated liquid pipe 14 Absorption Liquid pump 15 Dilute liquid pipe 16 Refrigerant conduit 17 Refrigerant liquid pipe 18 Refrigerant recirculation pipe 19, 20, 21 Open / close valve 22, 23 Branch pipe 24 Refrigerant liquid reservoir 25 Refrigerant blow pipe 26 Cold water pipe 27 Cooling water pipe 28 Cooling water pump 29 Controller 30 Refrigerant distributor 31 ・ 32 ・ 33 Temperature detector 34 ・ 35 Check valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-363562 (JP, A) JP-A-55-17065 (JP, A) JP-A-4-340066 (JP, A) 155656 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 306 F25B 41/00

Claims (2)

(57) [Claims] 1. An absorber, an evaporator, a condenser, a high-temperature regenerator,
In a double-effect absorption refrigerator in which a low-temperature regenerator, a low-temperature heat exchanger, a high-temperature heat exchanger and an absorption liquid pump are connected by piping to form a circulation cycle of the refrigerant and the absorption liquid, the discharge-side piping of the absorption liquid pump and the low-temperature At least one of the concentrated liquid pipe from the regenerator to the low-temperature heat exchanger and the intermediate liquid pipe from the high-temperature regenerator to the high-temperature heat exchanger is provided with a normally closed on-off valve, and the diluted liquid discharge port is connected to the inflow side pipe. And a controller that opens and closes the on-off valve when the operation of the absorption chiller is stopped, the controller being connected to be communicable via a branch pipe that opens in the liquid flow direction. 2. An absorber, an evaporator, a condenser, a high-temperature regenerator,
In a double-effect absorption refrigerator in which a low-temperature regenerator, a low-temperature heat exchanger, a high-temperature heat exchanger and an absorption liquid pump are connected by piping to form a circulation cycle of the refrigerant and the absorption liquid, the discharge-side piping of the absorption liquid pump and the low-temperature The concentrated liquid pipe from the regenerator to the low-temperature heat exchanger can communicate with the concentrated liquid pipe through a branch pipe with a normally closed on-off valve and a diluted liquid discharge port opened in the liquid flow direction of the inflow side pipe. An absorption refrigerator connected with a controller that opens the on-off valve when at least one of the chilled water temperature, the chilled water temperature, and the refrigerant temperature in the evaporator drops to a predetermined temperature.