JP2001263878A - Absorption refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an absorption refrigerating machine from running into an unoperatable state due to a refrigerant shortage even when the load is low or the temperature of cooling water drops. SOLUTION: This absorption refrigerating machine is constituted in such a way that, when the concentration of an absorbent detected by means of a concentration sensor 20 becomes lower than a set value, the gas extraction by means of this absorption refrigerating machine is limited or the gas extracting function of this machine is stopped by narrowing a flow control valve 16 installed to a bleeding tube 17 which connects the gas-phase section of an absorber 1 to the ejector 11 of a gas extracting device 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorption refrigerator (including an absorption chiller / heater).

[0002]

2. Description of the Related Art When an absorption refrigerator is operated at a low load or when the temperature of cooling water decreases, the concentration of the absorption liquid decreases, and the refrigerant to be evaporated by an evaporator becomes insufficient, so that the operation cannot be continued. Because there is a fear, a refrigerant pool is provided inside the machine,
It is designed so that operation can be continued even if the temperature of the cooling water drops.

[0003]

However, in order to continue the operation even if the temperature of the cooling water is considerably lowered, if the capacity of the refrigerant storage section is increased to hold a large amount of the refrigerant, the size of the apparatus can be reduced. Disappears. Therefore, it is necessary to be able to continue the operation without any problem even when the load is low or the temperature of the cooling water is lowered, and to reduce the size of the apparatus.

[0004]

SUMMARY OF THE INVENTION The present invention is, as a specific means for solving the above-mentioned problems of the prior art, in an absorption refrigerator equipped with an extraction device for extracting non-condensable gas in the device.

[0005] An absorption refrigerator having a first configuration, which comprises means for controlling the capacity of the bleeding device based on the concentration of the absorption liquid;

An absorption refrigerating machine having a second structure, comprising means for returning the non-condensable gas accumulated in a tank for storing the non-condensable gas of the bleeding device to the inside of the apparatus based on the concentration of the absorbing solution;
To solve the above-mentioned problem of the prior art.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. The absorption chiller illustrated divides the absorption liquid sent from the absorption liquid pump 2 by the absorption liquid pump 2 from the absorber 1 to a regenerator (not shown), and uses the absorption liquid returned to the absorber 1 as a power source to generate gas in the absorber 1. Is provided with an extraction device 10 for extracting air.

The bleeding device 10 has an ejector 11 at its upper part, and a main part 13 having a gas-liquid separating part 12 at its lower part.
And an absorption liquid introduction pipe that branches from the absorption liquid pipe 3 downstream of the absorption liquid pipe 3 extending from the bottom of the absorber 1 to a regenerator (not shown) with the absorption liquid pump 2 provided on the upstream side to reach the ejector 11. 14, an absorbent return pipe 15 extending from the bottom of the gas-liquid separation unit 12 to the gas phase of the absorber 1, and a flow control valve 16 on the way from the gas phase of the absorber 1 to the ejector 11. The non-condensable gas tank 18 provided in communication with the extended bleed pipe 17, the gas phase part 12 </ b> A in which the non-condensable gas of the gas-liquid separation part 12 is stored, and the non-condensable gas tank 18. Control for controlling the flow rate control valve 16 based on the concentration of the absorbing solution detected by the concentration sensor 20 and the concentration sensor 20 for detecting the concentration of the absorbing solution collected at the bottom of the absorber 1. Vessel 21
It is composed of

The end of the absorbent return pipe 15 rises to the middle of the gas-liquid separator 12 and opens to the gas phase of the absorber 1. Therefore, the absorbing liquid sent to the gas-liquid separating section 12 by the absorbing liquid pump 2
Accumulates from the bottom to the middle, not above it.

[0010] Then, the absorbing liquid pump 3
From the ejector 11 through the absorbent introduction pipe 14.
The gas in the absorber 1 is drawn into the ejector 11 through the bleed pipe 17 by the negative pressure created by the absorbing liquid that is supplied to the air and vigorously ejected, and the gas and liquid integrally enter the gas-liquid separation unit 12. .

The refrigerant vapor in the gas which is drawn into the gas-liquid separation unit 12 from the absorber 1 in a gas-liquid manner is absorbed by the absorption liquid in the gas-liquid separation unit 12. However, the non-condensable gas that is not absorbed by the absorbing liquid such as hydrogen generated in the machine due to metal corrosion or the like is separated from the absorbing liquid, floats, accumulates in the gas phase part 12A, and enters the non-condensing gas tank 18. Then, through the palladium cell 19 heated to a predetermined temperature by an electric heater (not shown), hydrogen of the non-condensable gas is discharged outside the apparatus.

In the absorption refrigerator of the present invention, the controller 21 controls the opening degree of the flow control valve 16 based on the concentration of the absorbent in the absorber 1 detected by the concentration sensor 20, for example, as shown in FIG.

That is, when the concentration of the absorbing solution detected by the concentration sensor 20 is 56% or more, the flow control valve 16 is fully opened, and when the concentration is 56% or less, the flow control valve 16 is opened.
Is fully closed, and when the density is in the range of 54 to 56%, the opening is controlled to be proportional to the density.

Therefore, the temperature of the cooling water supplied to the absorber 1 and the condenser (not shown) from the cooling water pipe 4 at a low load or the cooling water pipe is low, and the absorption of the refrigerant vapor by the absorbing liquid in the absorber 1 proceeds excessively. When the concentration of the absorbent detected by the concentration sensor 20 becomes lower than 56%, the opening degree of the flow control valve 16 is reduced, and the non-condensable gas in the absorber 1 and the evaporator 5 attached to the absorber 1 is removed. Emissions are reduced.

For this reason, the concentration of the non-condensable gas in the gas phase portion of the absorber 1 and the evaporator 5 increases, and the evaporation of the refrigerant in the evaporator 5 is suppressed. Accordingly, the amount of the refrigerant vapor supplied from the evaporator 5 to the absorber 1 is reduced, and the refrigerant is not excessively absorbed by the absorbent in the absorber 1, so that the decrease in the concentration of the absorbent is suppressed, and the refrigerant is suppressed. Inconvenience such as a shortage of the refrigerant sprayed on the cold water pipe 7 in the evaporator 5 by the pump 6 does not occur.

Second Embodiment Hereinafter, a second embodiment of the present invention will be described mainly with reference to FIG. The only difference between the absorption refrigerator illustrated in FIG. 3 and the absorption refrigerator illustrated in FIG. 1 is the installation position of the flow control valve 16.

That is, in the absorption refrigerator shown in FIG. 1, the flow control valve 16 is provided in the bleed pipe 17 extending from the absorber 1 to the ejector 11, but the flow control valve 16 shown in FIG.
In the absorption refrigerator of the embodiment, the flow control valve 16 is connected to the absorption liquid introduction pipe 14 extending from the absorption liquid pipe 3 to the ejector 11.
The flow control valve 16 is controlled by the controller 21 as shown in FIG.

Even if the flow control valve 16 installed in the absorption liquid introduction pipe 14 is controlled as shown in FIG. 2, the cooling water supplied to the absorber 1 and the condenser (not shown) from the cooling water pipe 4 at low load or when the cooling water pipe 4 is used. When the temperature of the water is low and there is a concern that the absorption of the refrigerant vapor by the absorbing liquid in the absorber 1 may proceed excessively, the opening of the flow control valve 16 is narrowed to remove the non-condensable gas in the absorber 1 and the evaporator 5. Emissions are reduced.

Therefore, also in the absorption refrigerator of this configuration, the concentration of the non-condensable gas in the absorber 1 and the evaporator 5 increases, and the evaporation of the refrigerant in the evaporator 5 is suppressed.
The amount of the refrigerant vapor supplied from the evaporator 5 to the absorber 1 is reduced, and the refrigerant is not excessively absorbed by the absorbing liquid in the absorber 1, whereby the chilled water pipe in the evaporator 5 by the refrigerant pump 6 is provided. There is no inconvenience such as a shortage of the refrigerant to be sprayed on 7.

[Third Embodiment] A third embodiment of the present invention will be described below mainly with reference to FIG. The absorption chiller illustrated in FIG. 4 is different from the absorption chiller illustrated in FIG. 1 in equipment configuration in that the gas phase unit of the absorber 1 and the non-condensing gas tank 18 are further provided with a gas having an on-off valve 22. Return pipe 2
3.

In the absorption refrigerator shown in FIG. 4, the controller 21 controls the flow control valve 16 provided in the bleed pipe 17 based on the concentration of the absorption liquid detected by the concentration sensor 20 as shown in FIG. When the control is performed and the flow control valve 16 is fully closed to stop the bleeding from the absorber 1, that is, when the concentration of the absorbing liquid detected by the concentration sensor 20 becomes 54% or less, the on-off valve 22 is fully opened. Non-condensable gas tank 18
The non-condensable gas accumulated in the reservoir 1 is returned to the absorber 1 and the evaporator 5 via the gas return pipe 23, so that the absorption of the refrigerant by the absorbing liquid in the absorber 1 is positively inhibited.

When the on-off valve 22 is fully opened, the temperature of the cooling water flowing through the cooling water pipe 4 decreases so that a considerable amount of non-condensable gas is returned from the non-condensable gas tank 18 to the absorber 1. Also, the controller 21 is configured so as to reduce the hydrogen discharge function of the palladium cell 19 and to refrain from energizing a heater (not shown).

Therefore, in the absorption refrigerator of the third embodiment shown in FIG. 4, the effect of suppressing the absorption of the refrigerant by the absorption liquid is smaller than in the absorption refrigerators of the first and second embodiments. Since it is strong and the evaporation of the refrigerant in the evaporator 5 is further suppressed, the amount of the refrigerant vapor supplied from the evaporator 5 to the absorber 1 is effectively reduced, and the refrigerant in the absorber 1 is excessively absorbed by the absorbing liquid. Things disappear quickly. Thus, the disadvantage that the refrigerant pump 6 runs short of the refrigerant sprayed on the cold water pipe 7 in the evaporator 5 does not occur.

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, in the absorption refrigerator of the second embodiment shown in FIG. 2, the gas phase part of the absorber 1 and the non-condensable gas tank 18 are connected to the open / close valve 2 as in the absorption refrigerator shown in FIG.
When the concentration of the absorbing solution detected by the concentration sensor 20 becomes 54% or less, the flow control valve 16 is fully closed to stop the bleeding from the absorber 1 when the concentration is 20% or less. The on-off valve 22 is fully opened, and the non-condensable gas stored in the non-condensable gas tank 18 is removed from the absorber 1 and the evaporator 5.
, The absorption of the refrigerant by the absorbing liquid can be positively inhibited.

The flow control valve 16 and the on-off valve 22 are controlled not by the concentration of the absorbing liquid whose absorption liquid concentration has been reduced by absorbing the refrigerant by the absorber 1, but by evaporating and separating the refrigerant by a high-temperature regenerator (not shown). It is also possible to detect the concentration of the concentrated intermediate absorption liquid or the concentration of the concentrated absorption liquid concentrated by evaporating and separating the refrigerant by a low-temperature regenerator (not shown), and perform the detection based on the detected concentration.

Further, a vacuum pump may be provided in the non-condensable gas tank 18 instead of the palladium cell 19, and the non-condensable gas accumulated in the non-condensable gas tank 18 may be periodically discharged, for example.

[0028]

As described above, according to the absorption refrigerator of the first aspect, means for controlling the capacity of the extraction device based on the concentration of the absorbing liquid is provided. Stopping the bleed function suppresses the discharge of non-condensable gas in the absorber and evaporator, thereby increasing the concentration of non-condensable gas in the gas phase of the absorber and evaporator, and evaporating the refrigerant in the evaporator. Thus, the amount of refrigerant vapor supplied from the evaporator to the absorber can be reduced to prevent the absorbing liquid from excessively absorbing the refrigerant in the absorber.

Therefore, when the load starts to be excessively absorbed by the absorbing liquid at a low load or as the cooling water temperature decreases, and the concentration of the absorbing liquid decreases, the capacity of the extraction device is limited or the extraction function is restricted. By stopping the operation, it is possible to prevent the operation from being disabled due to a shortage of the refrigerant. As a result, two contradictory problems, that is, downsizing of the device and expansion of the operation range, can be simultaneously achieved.

According to the second aspect of the present invention, there is provided an absorption refrigerator having means for returning the non-condensable gas accumulated in the tank for storing the non-condensable gas of the bleeding device to the inside of the apparatus based on the concentration of the absorbing liquid. By returning the non-condensable gas accumulated in the tank to the inside of the device, the evaporation of the refrigerant in the evaporator can be easily suppressed.

Therefore, the operation of reducing the amount of the refrigerant vapor supplied from the evaporator to the absorber and suppressing the absorption of the refrigerant by the absorbing liquid can be performed more quickly than the absorption refrigerator of the first aspect. Operational effects equal to or higher than those of the refrigerator can be obtained.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing a control example in the absorption refrigerator of the first embodiment.

FIG. 3 is an explanatory diagram showing a configuration of a second embodiment.

FIG. 4 is an explanatory diagram illustrating a configuration of a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorber 2 Absorbent pump 3 Absorbent pipe 4 Cooling water pipe 5 Evaporator 6 Refrigerant pump 7 Cold water pipe 10 Extraction device 11 Ejector 12 Gas-liquid separation part 13 Main body part 14 Absorbent liquid introduction pipe 15 Absorbent liquid return pipe 16 Flow control valve 17 Bleed tube 18 Non-condensable gas tank 19 Palladium cell 20 Concentration sensor 21 Controller 22 On-off valve 23 Gas return tube

Claims (2)

[Claims] 1. An absorption refrigerator having an extraction device for extracting non-condensable gas in the device, comprising: means for controlling the capacity of the extraction device based on the concentration of the absorbing liquid. 2. An absorption refrigerator having an extraction device for extracting non-condensable gas in the device, wherein the non-condensable gas stored in a tank for storing the non-condensable gas in the extraction device is returned to the device based on the concentration of the absorbing liquid. An absorption refrigerator comprising means.