KR20210101035A - Absorbed chiller and control method thereof - Google Patents

Abstract

According to an embodiment of the present invention, a chiller includes: an evaporator including a refrigerant spray part spraying a refrigerant, and exchanging heat between cold water and the refrigerant sprayed through the refrigerant spray part; an absorber receiving a gaseous refrigerant from the evaporator, through which coolant passes; a connection line connecting the absorber with a circulation line connected to the refrigerant spray part such that the refrigerant is injected into the evaporator, and including a first valve; a regenerator heating an absorbent supplied from the absorber; a condenser receiving a gasified refrigerant generated by the regenerator, through which coolant passes; and a control part opening and closing the first valve in accordance with the concentration of a liquefied refrigerant in the evaporator to send the liquefied refrigerant in the evaporator to the absorber. The control part determines the degree of opening of the first valve in accordance with state information of the absorbent discharged from the regenerator. Therefore, when determining whether the refrigerant is mixed with the absorbent, and subsequently performing a blowdown, the present invention can secure efficiency. Therefore, time to reach normal efficiency, which is an issue of existing technology, can be reduced, and, as a result, a system can be prevented from being entirely turned off.

Description

Absorption chiller {ABSORBED CHILLER AND CONTROL METHOD THEREOF}

The present invention relates to an absorption chiller, and more specifically, an absorption chiller capable of automatically measuring the degree of mixing of an absorption liquid in a refrigerant, and separating the absorption liquid from the refrigerant through a regenerator when more than a predetermined amount of absorption liquid is mixed in the refrigerant is about

The absorption chiller is a device for cooling the cold water by exchanging the refrigerant and the cold water without a separate compressor.

1 is a schematic view of a general absorption chiller (1).

Referring to Figure 1, the conventional absorption iron (1) is an evaporator (2) for exchanging refrigerant and cold water, an absorber (3) for absorbing the gaseous refrigerant evaporated in the evaporator (2) through an absorbent liquid, the absorber (3) and a regenerator (4) for separating the gaseous refrigerant from the absorption liquid supplied from the regenerator (4), and a condenser (5) for condensing the gaseous refrigerant by exchanging heat with the gaseous refrigerant separated in the regenerator (4) and cooling water.

The evaporator 2 and the absorber 3 may be implemented through a single shell, and the regenerator 4 and the condenser 5 may also be implemented through a single shell.

The cycle of the absorption chiller 1 will be described as follows.

The low-concentration absorption liquid (ie, the absorption liquid containing a relatively large amount of gaseous refrigerant) from the absorber 3 is supplied to the regenerator 4 through the low-concentration pipe 3'.

When the low-concentration absorption liquid is heated in the regenerator 4, the gaseous refrigerant is separated from the low-concentration absorption liquid. The high-concentration absorption liquid from which the gaseous refrigerant is separated (ie, the absorption liquid containing relatively little gas-phase refrigerant) is supplied back to the absorber 3 through the high-concentration pipe 4'.

A cooling water pipe 7 passes into the absorber 3, and the cooling water pipe 7 lowers the temperature in the absorber 3 to increase the absorption efficiency of the gaseous refrigerant by the absorber.

The gaseous refrigerant separated from the low-concentration absorption liquid in the regenerator 4 is supplied to the condenser 5 provided at one side of the regenerator 4 .

The condenser 5 is formed to condense the gaseous refrigerant by exchanging heat with the gaseous refrigerant and cooling water.

For example, a cooling water pipe 6 passes into the condenser 5 , and the cooling water pipe 7 exchanges heat with the gaseous refrigerant in the condenser 5 .

The liquid refrigerant condensed in the condenser 5 is supplied to the evaporator 2 through the high-pressure pipe 5 ′, and the liquid refrigerant and cold water exchange heat in the evaporator 2 .

For example, a cold water pipe 6 passes into the evaporator 2 , and the cold water pipe 6 and the liquid refrigerant exchange heat to cool the cold water.

The gaseous refrigerant generated by evaporation of the liquid refrigerant in the evaporator 2 is supplied to the absorber 3 on one side of the evaporator 2 .

Between the evaporator (2) and the absorber (3), the gaseous refrigerant from the evaporator (2) is supplied to the absorber (3), and the absorption liquid in the absorber (3) is not supplied to the evaporator (2) An eliminator 9 may be provided.

That is, the eliminator 9 passes the gaseous refrigerant generated in the evaporator 2 toward the absorber 3 and prevents the absorption liquid supplied to the absorber 3 from flowing into the evaporator 2 . can be formed to

On the other hand, even if the eliminator 9 is provided between the evaporator 2 and the absorber 3 , it is difficult to completely prevent the absorption liquid in the absorber 3 from flowing into the evaporator 2 .

That is, the absorption liquid in the absorber 3 may be introduced into the evaporator 2 little by little during operation of the absorption chiller 1 . When the absorption liquid flows into the evaporator 2 , not only the evaporation performance (ie, cooling performance of cold water) decreases, but also the operation efficiency of the absorption type chiller 1 as a whole may decrease.

In the case of the conventional absorption chiller (1), when the operating efficiency of the absorption chiller (1) or the cooling performance of the cold water decreases, a portion of the liquid refrigerant in the evaporator (2) is extracted to determine whether the absorbent liquid is mixed with the refrigerant did.

However, it is difficult to conclude that the decrease in the operating efficiency of the absorption chiller or the cooling performance of the cold water is necessarily due to the absorption liquid mixed in the refrigerant. (2) A part of the liquid refrigerant inside is extracted.

In addition, in the case of the conventional absorption chiller 1, if it is determined that the absorption liquid is mixed with the refrigerant more than a set amount, the blow valve 8 is opened to supply a part of the liquid refrigerant in the evaporator 2 to the absorber 3 .

In this case, a part of the liquid refrigerant in the evaporator 2 is supplied to the absorber 3, but the remaining liquid refrigerant is again supplied into the evaporator from the upper side of the evaporator 2, so that the refrigerant is not completely separated from the refrigerant. There is a problem in that the absorption chiller (1) is circulated.

In addition, with respect to the blowdown of such an absorption chiller, Korean Patent No. 10-1809963 discloses that the driver directly samples the refrigerant, measures the specific gravity to determine the level of the contaminated refrigerant, and then performs the blowdown so that the valve is automatically activated through an electrical signal. Performing on-off is disclosed.

However, with respect to this prior art, when the blowdown starts, the operation of the entire chiller is stopped, and accordingly, the entire refrigerant is moved to the absorber 3 and is driven in a very low efficiency state for a period of time to be filled again to a predetermined level. is paused Accordingly, since the operation continuity of the chiller is lowered, it is difficult to control the integrated system in the whole system, and the return time until the normal efficiency is very long, so there is a problem that the efficiency is lowered.

Korean Patent 10-1809963 (2018.01.18. Announcement)

A first object to be solved by the present invention is to provide an absorption chiller capable of ensuring efficiency when determining whether an absorption liquid is mixed with a refrigerant and performing a blowdown according thereto.

That is, an object of the present invention is to provide an absorption chiller capable of preventing the entire system from being turned off by reducing the time required to reach the normal efficiency, which has been a problem in the prior art.

Condensation may occur in the inlet pipe through which the refrigerant with a low temperature and high concentration in the absorber is introduced back to the regenerator, which may adversely affect the flow.

Accordingly, the second object to be solved by the present invention is to provide a blowdown method capable of preventing dew condensation from occurring in an inlet pipe in which a refrigerant having a low temperature and a high concentration in the absorber is introduced back to the regenerator.

Another object of the present invention is to provide a blowdown method capable of adjusting the blowdown speed by controlling the degree of opening and closing of the valve according to the temperature and concentration of the absorbent liquid without completely opening the blow valve during blowdown.

In order to achieve the above object, an evaporator having a refrigerant injection unit for injecting a refrigerant, and exchanging heat with the refrigerant injected through the refrigerant injection unit and cold water; an absorber through which a gaseous refrigerant is supplied from the evaporator, and through which cooling water passes; a connection line connecting the absorber to the circulation line connected to the refrigerant injection unit so that the refrigerant is injected into the evaporator and having a first valve; a regenerator for heating the absorbent liquid supplied from the absorber; a condenser to which the gaseous refrigerant generated in the regenerator is supplied and the cooling water passes through; and a control unit for flowing the liquid refrigerant of the evaporator to the absorber by opening and closing the first valve according to the concentration of the liquid refrigerant in the evaporator, wherein the control unit operates the first valve according to the state information of the absorption liquid discharged from the regenerator. It provides an absorption chiller, characterized in that determining the opening and closing amount.

Through the above solution, it is determined whether the absorbent liquid is mixed with the refrigerant, and when the blowdown is performed according to the determination, efficiency can be secured. Accordingly, it is possible to prevent the system from being turned off as a whole by reducing the time taken to reach the normal efficiency, which has been a problem in the prior art.

Further, it is possible to prevent dew condensation from occurring in the inlet pipe through which the refrigerant having a low temperature and a high concentration in the absorber is introduced back to the regenerator.

According to the present invention, the blowdown speed can be adjusted by controlling the degree of opening and closing of the valve according to the temperature and concentration of the absorbent liquid without completely opening the blow valve during blowdown.

1 is a view showing a conventional absorption chiller.
2 is a view showing an absorption type chiller according to the present invention.
FIG. 3 is a view showing the evaporator and the absorber shown in FIG. 2 .
4 is a flowchart illustrating an operation of the chiller including the blowdown control unit of FIG. 3 .
FIG. 5 is a view showing the flow of the absorbent liquid when the blowdown of FIG. 4 is applied.
6A and 6B are graphs showing the efficiency before and after applying the blowdown of FIG. 4 .

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. As used herein, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and/or "comprising" means that a referenced component, step and/or action excludes the presence or addition of one or more other components, steps and/or actions. I never do that.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly specifically defined.

In the drawings, the thickness or size of each component is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component do not fully reflect the actual size or area.

In addition, angles and directions mentioned in the process of describing the structure of the embodiment are based on those described in the drawings. In the description of the structure constituting the embodiment in the specification, if the reference point for the angle and the positional relationship are not clearly mentioned, reference is made to the related drawings.

2 is a view showing an absorption chiller according to the present invention, and FIG. 3 is a view showing the evaporator and the absorber shown in FIG. 2 .

2, the absorption chiller 10 according to the present invention is an evaporator 200 for exchanging a refrigerant (eg, water) and cold water, an absorber 300 to which a gaseous refrigerant is supplied from the evaporator 200, It may include a regenerator 400 for heating the absorbent liquid supplied from the absorber 300 and a condenser 500 to which the gaseous refrigerant generated in the regenerator 400 is supplied.

The evaporator 200 and the absorber 300 may be implemented as a single shell, and the regenerator 400 and the condenser 500 may also be implemented as a single shell.

The evaporator 200 may include a refrigerant pump 251 for pressurizing the refrigerant therein, and a refrigerant injection unit 252 for injecting the refrigerant pressurized by the refrigerant pump 251 .

Specifically, the liquid refrigerant supplied from the condenser 500 through the high-pressure pipe 550 may be accommodated in the evaporator 200 . The liquid refrigerant contained in the evaporator 200 is pressurized by the refrigerant pump 251 provided at the lower end of the evaporator 200 , and is guided to the upper part of the evaporator 200 through the circulation line 250 .

The liquid refrigerant guided to the upper part of the evaporator 200 through the circulation line 250 may be injected into the evaporator 200 through the refrigerant spray unit 252 . At this time, the refrigerant spraying unit 252 may be formed to spray the liquid refrigerant in the form of fine particles.

That is, the refrigerant spraying unit 252 may be provided above the evaporator 200 . More specifically, the refrigerant injection unit 252 may be provided at an upper portion of the evaporator 200 .

A cold water pipe 600 through which cold water flows may pass through the evaporator 200 . That is, a part of the cold water pipe 600 may be disposed in the evaporator 200 .

Accordingly, the refrigerant sprayed from the refrigerant spraying unit 252 and the cold water flowing through the cold water pipe 600 exchange heat to cool the cold water. The cooled cold water may be used as a heat exchange medium in a separate air conditioner (not shown) or an indoor unit (not shown).

The absorber 300 may be formed such that a gaseous refrigerant is supplied from the evaporator 200 and an absorbent liquid is supplied through the regenerator 400 described above. The absorption liquid may be a lithium bromide (LiBr) aqueous solution.

Specifically, the gaseous refrigerant evaporated through heat exchange with cold water in the evaporator 200 may be supplied to the absorber 300 provided at one side of the evaporator 200 .

A first eliminator E1 is provided between the evaporator 200 and the absorber 300 . The first eliminator E1 may be formed to pass a gas and block a liquid. In addition, the pressure inside the evaporator 200 is higher than the pressure inside the absorber 300 .

Accordingly, the gaseous refrigerant generated in the evaporator 200 may be guided to the absorber 300 through the first eliminator E1 . The gaseous refrigerant guided to the absorber 300 may be absorbed in the absorption liquid supplied to the absorber 300 .

On the other hand, the absorbent liquid in the absorber 300 cannot be guided to the evaporator 200 by the first eliminator E1. That is, the first eliminator E1 may be formed to prevent the absorption liquid in the absorber 300 from being guided into the evaporator 200 .

A cooling water pipe 700 may pass through the absorber 300 . This is to lower the temperature in the absorber 300 because heat is generated when the absorption liquid absorbs the gaseous refrigerant.

That is, the absorption efficiency of the gaseous refrigerant by the absorption liquid may be increased by the cooling water pipe 700 passing through the absorber 300 .

An absorption liquid pump 351 may be provided at a lower end of the absorber 300 . The absorbent liquid that has absorbed the gaseous refrigerant in the absorber 300 may be guided to the regenerator 400 by driving the absorbent liquid pump 351 .

More specifically, the absorber 300 may be connected to the regenerator 400 through an absorbent liquid supply line 350 , and the absorbent liquid pump 351 may be provided on the absorbent liquid supply line 350 .

The regenerator 400 may be formed to heat the absorbent liquid supplied from the absorber 300 (hereinafter, also referred to as “low-concentration absorbent liquid”).

The regenerator 400 may be formed to heat the low-concentration absorbent liquid supplied from the absorber 300 by a heat source (eg, steam, hot water or gas, etc.) in the high-temperature regenerator 100 .

When the absorbent liquid is heated in the regenerator 400 , a gaseous refrigerant may be separated from the absorbent liquid. The gaseous refrigerant separated from the absorption liquid is guided to the condenser 500 at one side of the regenerator 400 .

In this case, a second eliminator E2 may be provided between the regenerator 400 and the condenser 500 provided on one side of the regenerator. The second eliminator E2 may be formed to pass a gas and block a liquid. In addition, the pressure inside the regenerator 400 is higher than the pressure inside the condenser 500 . Accordingly, the gaseous refrigerant generated in the regenerator 400 may be guided to the condenser 500 through the second eliminator E2 . The gaseous refrigerant guided to the condenser 500 is condensed into the liquid refrigerant in the condenser 500 .

On the other hand, the liquid refrigerant in the condenser 500 cannot be guided to the regenerator 400 by the second eliminator E2. That is, the second eliminator E2 may be formed to prevent the liquid refrigerant in the condenser 500 from being guided into the regenerator 400 .

The absorbent liquid from which the gaseous refrigerant is separated by being heated in the regenerator 400 may be recovered to the absorber 300 through the absorbent liquid recovery line 450 . At this time, in order to recover the absorbent liquid through the absorbent liquid recovery line 450 , the absorber 300 is preferably disposed below the regenerator 400 .

One end of the absorbent liquid recovery line 450 may communicate with the regenerator 400 , and the other end of the absorbent liquid recovery line 450 may communicate with the absorber 300 .

An absorbent liquid spraying unit 452 may be provided at the other end of the absorbent liquid recovery line 450 . The absorbent liquid spraying unit 452 may be formed to spray the absorbent liquid into the absorber 300 in the form of fine particles. When the absorbent liquid is sprayed in the form of fine particles, absorption efficiency of the gaseous refrigerant by the absorbent liquid may be increased.

The absorbent liquid supply line 350 may be formed to heat exchange with the absorbent liquid recovery line 450 . Specifically, a portion of the absorption liquid supply line 350 may exchange heat with a portion of the absorption liquid recovery line 450 through the absorption liquid heat exchanger 900 .

Specifically, a portion of the absorption liquid supply line 350 and a portion of the absorption liquid recovery line 450 may pass through the absorption liquid heat exchanger 900 . That is, through the absorption liquid heat exchanger 900 , heat exchange may be performed between the low concentration absorption liquid in the absorption liquid supply line 350 and the high concentration absorption liquid in the absorption liquid recovery line 450 .

At this time, the low concentration absorption liquid in the absorption liquid supply line 350 may absorb heat, and the high concentration absorption liquid in the absorption liquid recovery line 450 may release heat.

Here, the low-concentration absorption liquid may indicate an absorption liquid in a state in which the gaseous refrigerant is absorbed by the absorber 300 , and the high-concentration absorption liquid may indicate an absorption liquid in a state in which the vapor-phase refrigerant is separated in the regenerator 400 .

By the absorption liquid heat exchanger 900 , the separation efficiency of the gaseous refrigerant from the absorbent liquid in the regenerator 400 (ie, the regeneration efficiency of the absorbent liquid) is increased, and at the same time, the absorption efficiency of the gaseous refrigerant by the absorbent liquid in the absorber 300 is increased. (that is, the absorption efficiency of the absorbent liquid) can be increased.

At this time, when the high concentration absorption liquid passing through the absorption liquid heat exchanger 900 performs heat exchange with the low concentration absorption liquid in a state where the absorption liquid concentration is high, if a large amount of refrigerant is injected into the low concentration absorption liquid from the absorber 300, the temperature is lowered. When the low-temperature, low-concentration absorbent liquid and the high-concentration absorbent liquid in the absorbent liquid recovery line 450 perform heat exchange, crystals may occur on the absorbent liquid recovery line 450 side.

Such crystallization of the high-concentration absorption liquid may become a factor impeding the flow in the recovery line 450 , thereby greatly reducing the efficiency of the apparatus.

To this end, in the embodiment of the present invention, the sensor 451 is formed in the outlet region of the absorption liquid heat exchanger 900 and the temperature or concentration of the recovery line 450 in the outlet region of the heat exchanger 900 is sensed.

In addition, in the embodiment of the present invention, the blowdown control unit 150 for controlling the degree of opening and closing of the blow valve 261 based on the sensed value from the sensor 451 may be provided separately.

When the blowdown starts, the blowdown control unit 150 periodically reads the concentration or temperature from the corresponding sensor 451 and controls the degree of opening and closing of the valve 261 according to the detected value to prevent crystallization. carry out

In addition, since other modules of the chiller 10 operate normally during the blowdown operation, the refrigerant is discharged and the low-concentration refrigerant is re-injected at the same time, so that the blowdown can be performed without a section in which the efficiency is 0%.

Therefore, even during blowdown, the operation of the chiller 10 that satisfies 50% or more of efficiency is maintained, thereby preventing the chiller 10 from being turned off and then turned on again during blowdown, and the waiting period until normal operation is reduced. can be shortened.

The blowdown control unit 150 may open the blow valve 261 with a specific value of opening/closing amount according to a temperature or concentration applied according to a formula programmed as a control module such as a microcomputer.

Alternatively, the blowdown control unit 150 is a simple opener, and may perform an operation of opening and closing the blow valve 261 by a corresponding size according to the opening/closing amount received from the external main control unit (not shown), but is limited thereto. no.

Such blowdown will be described in detail later.

On the other hand, the condenser 500 may be formed so that the gaseous refrigerant generated in the regenerator 400 is supplied. That is, the gaseous refrigerant separated from the absorption liquid in the regenerator 400 may be supplied to the condenser 500 .

The aforementioned cooling water pipe 700 may pass through the condenser 500 . Accordingly, the gaseous refrigerant supplied into the condenser 500 may be condensed by heat exchange with the cooling water pipe 700 .

The cooling water pipe 700 may be provided to sequentially pass through the absorber 300 and the condenser 500 described above.

This is because the absorber 300 requires more cooling water than the condenser 500 .

The cooling water guided to the cooling water pipe 700 may pass through the absorber 300 and the condenser 500 and then be cooled again through a separate cooling tower (not shown).

The liquid refrigerant condensed in the condenser 500 may be guided to the evaporator 200 through the refrigerant pipe 550 . At this time, in order to guide the liquid refrigerant through the refrigerant pipe 550 , the condenser 500 may be disposed above the evaporator 200 .

On the other hand, it is preferable that the inside of the evaporator 200 is maintained so that only the pure refrigerant not containing the absorption liquid exists. When the absorption liquid is included in the evaporator 200 , the evaporation efficiency and the overall efficiency of the absorption chiller 10 may be reduced. When the efficiency is reduced as described above, the efficiency of the absorption chiller 10 may be improved by performing blowdown.

Hereinafter, the operation of the chiller according to the embodiment of the present invention will be described with reference to FIGS. 3 to 6 .

3 is an enlarged view of the chiller 10 including the blowdown control unit 150, FIG. 4 is a flowchart illustrating the operation of the chiller including the blowdown control unit of FIG. 3, and FIG. 5 is the blowdown application of FIG. It is a view showing the absorption liquid flow at the time, and FIGS. 6A and 6B are graphs showing the efficiency before and after applying the blowdown of FIG. 4 .

The absorption chiller 10 according to the present invention may include an evaporator sensor 210 for detecting the concentration or specific gravity of the liquid refrigerant contained in the evaporator 200 .

The evaporator sensor 210 may be provided on one side of the evaporator 200 to detect the amount of the absorption liquid in the liquid refrigerant contained in the evaporator 200 .

At this time, based on the concentration of the refrigerant contained in the evaporator 200 , blowdown, which is the driving of the absorption chiller 10 for separating the absorption liquid from the refrigerant, may be performed.

Referring to FIG. 3 , the absorption chiller 10 according to the present invention may further include a connection line 260 connecting the aforementioned circulation line 250 and the absorber 300 , and the connection line 260 . A blow valve 261 may be provided.

First, as shown in FIG. 4 , while the absorption chiller 10 is normally driven ( S10 ) and the absorption liquid flows, the blowdown control unit 150 detects the specific gravity of the refrigerant or the concentration of the refrigerant in the evaporator 200 .

As such, the detection of the refrigerant may read the specific gravity of the refrigerant through the evaporator sensor 210 or a specific gravity sensing unit (not shown), but is not limited thereto.

In addition, when the blowdown control unit 150 decreases the efficiency of the absorption chiller 10 to below the reference value (S20), it is determined that the absorbent liquid is contained in the evaporator 200 of the absorption chiller 10 beyond a predetermined range. can

As such, when it is determined that the refrigerant in the evaporator is mixed with the refrigerant in the evaporator 200 by a predetermined amount or more, the blowdown control unit 150 commands the blowdown driving.

When the blowdown driving is received from the main controller, the blowdown control unit 150 controls the blowdown valve 261 to open the blowdown valve 261 by an initial value (S30).

As described above, the above-described refrigerant pump 251 is driven in a state in which the blow valve 261 is opened as much as the initial value, and the refrigerant in the evaporator 200 is supplied to the absorber 300 .

That is, when the blow valve 261 is opened together with the driving of the refrigerant pump 251 , the refrigerant in the evaporator 200 sequentially passes through the absorber 300 and the regenerator 400 .

At this time, the blowdown control unit 150 reads a detection value for the temperature or concentration of the recovery line 450 in the outlet region of the heat exchanger 900 from the sensor 451 in the outlet region of the absorption liquid heat exchanger 900 . (S40).

In this case, the blowdown control unit 150 may store a program for calculating the degree of opening and closing of the blow valve 261 for the corresponding temperature, and calculates the opening/closing value of the blow valve 261 for the corresponding temperature.

On the other hand, the blowdown control unit 150 may store a program for calculating the degree of opening and closing the blow valve 261 for the corresponding concentration, and may calculate the opening and closing value of the blow valve 261 for the corresponding concentration accordingly.

At this time, when the corresponding temperature or concentration is within the critical range (S50), the blowdown control unit 150 calculates an open/close value of the blow valve 261 according to the programmed value, and transmits it to the blow valve 261 to correspond to It is possible to open the blow valve 261 only by the opening/closing value (S60).

As described above, the calculated value may be calculated as a value capable of preventing crystallization in the recovery line of the high-concentration recovery solution due to the temperature of the low-concentration recovery solution crossing in the recovery solution heat exchanger during blowdown being too low.

As described above, by setting the critical range so as not to lower the crystallization temperature of the high-concentration recovery liquid, and opening and closing the blow valve 261 while controlling blowdown, it is possible to prevent a significant decrease in efficiency due to crystallization.

At this time, since the blow-down operation is not performed in the state in which the blow valve 261 is completely opened and closed, the absorption chiller 10 continuously maintains the operation (S70).

Therefore, when the specific gravity of the refrigerant in the evaporator 200 is very high and the refrigerant is out of the contaminated state (S80), the blow valve 261 is turned off to end the blowdown operation (S90).

On the other hand, when the temperature or concentration of the absorbent liquid completely deviates from the critical range, it is determined that the blowdown must be performed urgently, and the blowdown is urgently performed by completely opening and closing the blow valve 261 ( S100 ).

In this case, the temperature of the high-concentration recovery solution is very high or the concentration is very low, and it may be defined as a state in which crystallization is difficult to occur.

As described above, within the stable range of crystallization, the blow-down can be selectively performed according to the current state by completely opening and closing the blow valve 261 to proceed with the emergency blow-down (S110).

When the blow-down is performed in this way, as shown in FIG. 5 , the refrigerant of the evaporator 200 passes through the absorber 300 , and the low-concentration absorption liquid of the absorber 300 is changed to an ultra-low-concentration absorption liquid having a very low temperature.

As the low-temperature, ultra-low-concentration absorbent liquid flows along the circulation line 250, heat exchange is performed between the high-temperature, high-concentration absorbent liquid of the regenerator 400 and the absorbent liquid heat exchanger 900, and is again injected into the regenerator 400 and separated.

As shown in Figure 6b, if the blowdown is performed from the point in time t6 when it is determined that the refrigerant is in a contaminated state because the efficiency is lowered, the blowdown operation of the present invention is performed again until the efficiency is 100% and the refrigerant is out of the contaminated state ( BD: t6 to t7) proceeds.

Accordingly, as shown in FIG. 6a in the related art, all the blow valves 261 are opened at once and the efficiency of the chiller 10 is 0% (t2 to t3), that is, after all the refrigerant is discharged to the evaporator 200, the refrigerant is not contaminated Without the chiller off state until it is full, the chiller 10 continuously operates with an efficiency of 50% or more as shown in FIG. 6B to perform blowdown.

As shown in Fig. 5a, blowdown is started (t2) by such a blowdown drive, and the blowdown proceeds within a shorter time than the time taken until the normalization time t4 when the refrigerant is completely filled while filling the refrigerant again, such a short time Efficiency is further secured because the chiller 10 is not turned off even inside.

In addition, it is possible to perform blowdown while preventing crystallization of the high-concentration recovery solution, thereby preventing all malfunctions occurring during blowdown.

In addition, according to the absorption chiller 10, the separation of the absorption liquid from the coolant can be performed automatically based on the determination of whether the absorption liquid is contained in the coolant.

In the above, preferred embodiments of the present invention have been shown and described, but the present invention is not limited to the specific embodiments described above, and in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Various modifications may be made by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Claims (20)

an evaporator having a refrigerant injection unit for injecting a refrigerant, and exchanging heat with the refrigerant injected through the refrigerant injection unit and cold water;
an absorber through which a gaseous refrigerant is supplied from the evaporator, and through which cooling water passes;
a connection line connecting the absorber to the circulation line connected to the refrigerant injection unit so that the refrigerant is injected into the evaporator and having a first valve;
a regenerator for heating the absorbent liquid supplied from the absorber;
a condenser to which the gaseous refrigerant generated in the regenerator is supplied and the cooling water passes through;
A control unit for flowing the liquid refrigerant of the evaporator to the absorber by opening and closing the first valve according to the concentration of the liquid refrigerant in the evaporator
including,
and the control unit determines the opening/closing amount of the first valve according to the state information of the absorbent liquid discharged from the regenerator. According to claim 1,
A sensor for detecting the concentration of the liquid refrigerant contained in the evaporator is disposed on one side of the evaporator to sense the amount of the absorption liquid in the liquid refrigerant, the absorption chiller. 3. The method of claim 2,
The absorption chiller, characterized in that it further comprises an absorption liquid recovery line for flowing a high-concentration absorption liquid regenerated from the regenerator. 4. The method of claim 3,
The absorption liquid recovery line is characterized in that extended to deliver the absorbent liquid of high concentration regenerated from the regenerator to the absorber, absorption chiller. 5. The method of claim 4,
The absorption chiller,
Absorption-type chiller, characterized in that it further comprises an absorption liquid supply line for discharging the low-concentration absorption liquid in the absorber. 6. The method of claim 5,
The absorption chiller,
The absorption-type chiller, characterized in that the absorption liquid supply line and the absorption liquid recovery line further include an absorption liquid heat exchanger for performing heat exchange. 7. The method of claim 6,
An absorption type chiller, characterized in that an absorption liquid sensor for detecting the state of the high concentration absorption liquid is further disposed in the absorption liquid recovery line passing through the absorption liquid heat exchanger. 8. The method of claim 7,
the control unit
The absorption-type chiller, characterized in that the opening/closing amount of the first valve is calculated according to the state information of the high-concentration absorption liquid from the absorption liquid sensor. 9. The method of claim 8,
Wherein the control unit controls the opening and closing amount of the first valve to maintain a state in which the high-concentration absorption liquid is not crystallized, the absorption chiller. 10. The method of claim 9,
When the concentration or temperature of the high-concentration absorption liquid is within a critical range, the control unit partially opens the first valve. 11. The method of claim 10,
The control unit, while the first valve is opened, characterized in that the control so that the absorption type chiller is operated, absorption chiller. an evaporator having a refrigerant injection unit for injecting a refrigerant, and exchanging heat with the refrigerant injected through the refrigerant injection unit and cold water; an absorber through which a gaseous refrigerant is supplied from the evaporator, and through which cooling water passes; a regenerator for heating the absorbent liquid supplied from the absorber; In the control method of an absorption chiller comprising a condenser to which the gaseous refrigerant generated in the regenerator is supplied and the cooling water passes,
discharging low-temperature cold water by normally driving the absorption chiller;
discharging the refrigerant of the evaporator to the absorber when the efficiency of the absorption chiller is lowered; and
adjusting the opening/closing amount of the first valve for discharging the refrigerant of the evaporator to the absorber according to the state information of the absorbent liquid discharged from the regenerator
A control method of an absorption chiller comprising a. 13. The method of claim 12,
The step of discharging the refrigerant of the evaporator to the absorber,
A control method of an absorption chiller, characterized in that the efficiency of the absorption chiller is determined according to the concentration of the liquid refrigerant in the evaporator. 14. The method of claim 13,
A sensor for detecting the concentration of the liquid refrigerant accommodated in the evaporator is disposed on one side of the evaporator to sense the amount of the absorption liquid in the liquid refrigerant, the control method of the absorption chiller. 15. The method of claim 14,
The absorption chiller includes an absorption liquid recovery line through which a high-concentration absorption liquid regenerated from the regenerator flows;
The control method of the absorption chiller, characterized in that it further comprises an absorption liquid supply line for discharging the low-concentration absorption liquid in the absorber. 16. The method of claim 15,
The method for controlling an absorption chiller, characterized in that it further comprises the step of performing heat exchange between the absorption liquid supply line and the absorption liquid recovery line in an absorption liquid heat exchanger. 17. The method of claim 16,
The step of adjusting the opening and closing amount of the first valve is
A control method of an absorption chiller, characterized in that the state of the high concentration absorption liquid is sensed in the absorption liquid recovery line passing through the absorption liquid heat exchanger. 18. The method of claim 17,
The step of adjusting the opening and closing amount of the first valve is
The control method of an absorption chiller, characterized in that the opening and closing amount of the first valve is controlled to maintain a state in which the high-concentration absorption liquid is not crystallized. 19. The method of claim 18,
The step of adjusting the opening and closing amount of the first valve is
When the concentration or temperature of the high-concentration absorbent liquid is within a critical range, the first valve is partially opened. 20. The method of claim 19,
While the first valve is opened, the control method of the absorption chiller, characterized in that the control to operate the absorption chiller.

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